[Field of the Invention]

[0001]

The present invention relates to a roll forging machine and roll forging method in which forming with dies is performed on a material for forging using a pair of roll dies. More specifically, the present invention relates to a roll forging machine and roll forging method in which materials to be shaped are fed to a pair of roll dies one after another with two carrying units and shaping with dies is performed successively using the pair of roll dies to improve productivity.

[Background of the Invention]

[0002]

Regarding production of a forging as a metal part, a working method is known in which a desired product is formed through forging press, etc., after the material has been preformed beforehand into a desired form. This preforming is also called as preforging, etc., and a roll forging machine (also called as forging roll) is known as a kind of forging machine for performing such working (see, e.g., Patent Document l).

[0003]

Further, techniques of a robot hand for forging roll are known in which an impact can be prevented from being transferred to the robot hand even if such impact is applied to a metal material during roll forging in a forging roll (see, e.g., Patent Document 2). In such techniques, a robot hand is provided on the wrist of the second arm of the robot, and an arrangement is disclosed in which the robot is of an articulated type that has a first arm, a second arm and so on, and the robot controlling unit controls movement of the robot hand. Furthermore, techniques of a forging roll are known which necessitate a low cost without increasing the space for installation, improve the cycle time twice and allow an expensive forging press to be utilized efficiently (see, e.g., Patent Document 3).

[Prior Technical Documents]

[Patent Documents]

[0004] Patent Document 1 ^" Publication of Examined Patent Application No. S52-8783 (JP, S52-8783, B)

Patent Document 2- Publication of Examined Patent Application No. Hl-33262 (JP, H01-33262, B)

Patent Document 3: Publication of Patent Application No. H5-169176 (JP, H05-169176, A)

Patent Document 4: Publication of Patent Application No. 3435314 (JP, 3435314, B)

[Summery of the Invention]

[Problems to be Solved by the Invention]

[0005]

On the other hand, regarding a roll forging machine, there are plenty of requirements for improving productivity. However, although Patent Documents 1 and 2 disclose techniques of composition of roll forging machines, they do not disclose improvement of productivity by a roll forging machine. Also, although Patent Document 3 discloses techniques of composition of a robot hand, there is no disclosure of further improvement of productivity by a roll forging machine. Moreover, although Patent Document 4 discloses techniques of a forging roll having a purpose of improving the cycle time, the techniques require two sets of roll set, i. e., portions for performing roll forming, such as a first roll with a first manitong and a second roll with a second manitong, and remain to merely provide improvement of the cycle time twice compared with a previous roll forging machine having a set of roll set. Thus, many matters still remain to be improved.

[0006]

That is, there are problems of lowering productivity such that roll forging is not performed in the step where the billets is pushed out with the first pusher turned and caused to be gripped by the first manitong, in the step where the billet is pushed out with the second pusher turned and caused to be gripped by the first manitong, in the step of feeding out through a first outward conveyor or second outward conveyor, or the like. Further, the techniques of Patent Document 4 require a first roll set and second roll set that are expensive and bring problems such as economic problems, problems of maintenance in case when forming is not performed. [0007]

The present invention is made for solving the above mentioned problems, attaining the following objects.

It is an object of the present invention to provide a roll forging machine and roll forging method in which two carrying units are provided corresponding to a pair of roll dies, materials for forging are fed to a pair of roll dies one after another with the two carrying units and shaping with dies is performed successively using the pair of roll dies to improve productivity.

It is another object of the present invention to provide a roll forging machine and roll forging method in which interference between robot hands are prevented in case where two carrying units are provided corresponding to a pair of roll dies.

[Means to Solve the Problems]

[0008]

The present invention provides the following features for attaining the above mentioned objects.

The roll forging machine according to the first aspect of the invention comprises:

a pair of roll driving axles that are provided to be rotatable on the body of the roll forging machine and caused to be rotated driven by a driver, a pair of roll dies that are provided on the pair of roll driving axles respectively and on which a plurality of shaping dies for shaping are formed with a predetermined space therebetween, and

carrying units for carrying materials to be shaped to a receiving position of the materials to be shaped, to shaping positions with the plurality of shaping dies on the pair of roll dies and to a shaped article carrying out position, ^*

wherein the carrying units comprises ^*

a first robot having a robot hand moving along a first rectangular route for movement including a straight route for movement in shaping connecting the positions corresponding to the shaping positions with the plurality of shaping dies and a first route for turning aside spaced apart on one side by a predetermined amount from the straight route for movement in shaping, and

a second robot having a robot hand moving along a second rectangular route for movement including the straight route for movement in shaping and a second route for turning aside spaced apart on the other side by a predetermined amount from the straight route for movement in shaping! and wherein the first robot and the second robot is controlled respectively such that the robot hand of the second robot moves along the part of the second rectangular route for movement other than the straight route for movement in shaping when the robot hand of the first robot moves along the straight route for movement in shaping and the robot hand of the first robot moves along the part of the first rectangular route for movement other than the straight route for movement in shaping when the robot hand of the second robot moves along the straight route for movement in shaping.

[0009]

The roll forging machine according to the second aspect of the invention is such that, in the first aspect, the receiving position of the materials to be shaped and the shaped article carrying out position are disposed in the extension of the route for movement in shaping.

The roll forging machine according to the third aspect of the invention is such that, in any one of the first to second aspects, the first robot and the second robot are articulated robots respectively.

[0010]

The roll forging machine according to the fourth aspect of the invention is such that, in the third aspect, each of the first robot and the second robot comprises a turning base that is fixed to the machine body and able to make turning movement, a plurality of arms that are connected in series so as to make swinging movement or turning movement relative to each other and one end of the serial arms is connected to the turning base to be able to make swinging movement, and a robot hand that that has a gripping portion of a material to be shaped and is connected to the other end of the serial arms.

[0011]

The roll forging machine according to the fifth aspect of the invention is such that, in any one of the first to fourth aspect, one of the first robot and the second robot is one of a floor type and the other is one of a hung type.

The roll forging machine according to the sixth aspect of the invention is such that, in any one of the first to fourth aspect, the first robot and the second robot are ones of a floor type disposed on their respective positions having different heights. [0012]

The roll forging machine according to the seventh aspect of the invention is such that, in any one of the first to sixth aspect, the robot hand of the first robot moves from the receiving position to the first step position for shaping with dies, when the robot hand of the second robot moves from the final step position for shaping to the carrying out position, and the robot hand of the second robot moves from the receiving position to the first step position for shaping with dies, when the robot hand of the first robot moves from the final step position for shaping to the carrying out position.

[0013]

The roll forging method according to the eighth aspect of the invention is such that, using a roll forging machine comprising:

a pair of roll driving axles that are provided to be rotatable on the body of the roll forging machine and caused to be rotated driven by a driver, a pair of roll dies that are provided on the pair of roll driving axles respectively and on which a plurality of shaping dies for shaping are provided with a predetermined space therebetween, and

carrying units for carrying materials to be shaped to a receiving position of the materials to be shaped, to shaping positions with the plurality of shaping dies on the pair of roll dies and to a shaped article carrying out position,

said carrying unit comprising:

a first robot having a robot hand moving along a first rectangular route for movement including a straight route for movement in shaping connecting the positions corresponding to the shaping positions with the plurality of shaping dies and a first route for turning aside spaced apart on one side by a predetermined amount from the straight route for movement in shaping, and a second robot having a robot hand moving along a second rectangular route for movement including the straight route for movement in shaping and a second route for turning aside spaced apart on the other side by a predetermined amount from the straight route for movement in shaping!

wherein the robot hand of the second robot moves along the part of the second rectangular route for movement other than the route for movement in shaping when the robot hand of the first robot moves along the route for movement in shaping, the robot hand of the first robot moves along the part of the first rectangular route for movement other than the route for movement in shaping when the robot hand of the second robot moves along the route for movement in shaping, and

either one of the first robot and the second robot can perform shaping with the pair of roll dies.

[0014]

The roll forging method according to the ninth aspect of the invention is such that, in the eighth aspect, the robot hand of the first robot moves from the receiving position to the first step position for shaping with dies, when the robot hand of the second robot moves from the final step position for shaping to the carrying out position, and

the robot hand of the second robot moves from the receiving position to the first step position for shaping with dies, when the robot hand of the first robot moves from the final step position for shaping to the carrying out position.

[Advantageous Effects of the Invention]

[0015]

With the roll forging machine according to the present invention, shaping of materials to be shaped gripped by a first carrying unit (first robot) or a second carrying unit (second robot) can be performed one after another with a pair of roll dies while the pair of dies are kept rotating continuously, thus improving productivity. For example, when the robot hand of the first robot (or the second robot) moves from a receiving position of materials to be shaped to a position of first shaping step with dies (for example, a first step position), the robot hand of the second robot (or the first robot) moves from a position of final shaping step with dies (for example, fourth step position) to a shaped article carrying out position. In such a manner, the robot hands of the first robot and the second robot can be prevented from interfering with each other and shaping with a pair of dies cab be performed successively.

[0016]

With this roll forging machine, two robots are operated in rotation. For this sake, the time for feeding operation of materials to be shaped and the time for carrying out shaped articles are not loss time now, though these were loss times in conventional roll forging machines. Further, this roll forging machine has a composition such that two robot hands are disposed in the upper and lower positions individually so as to avoid interference therebetween, thus allowing two carrying units to be operated in rotation. With this, improvement in productivity by the roll forging machine can be attained.

[0017]

Further, although two sets of roll dies were necessary for improving productivity with conventional roll forging machines, this roll forging machine does not require two sets of roll dies, so that reduction of expense for fabricating dies, spaces for maintaining dies, operation times for exchanging dies, or the like can be attained. Therefore, a large economic merit can be obtained.

[0018]

The roll forging method in the roll forging machine is one in which roll forging (shaping with a pair of roll dies) is performed by controlling the two robots in a manner such that, when the robot hand of one robot moves along the route for movement in shaping, the robot hand of the other robot moves along a first route for turning aside or the second route for turning aside. As such, the robot hands of both robots do not interfere with each other and shaping is performed by feeding materials to be shaped to a pair of roll dies one after another, thus providing improvement in productivity.

[Brief Description of Drawings]

[0019]

Fig. 1 is a front view showing an embodiment of a roll forging machine according to the present invention.

Fig. 2 is a plan view of the roll forging machine.

Fig. 3 is a front view of the robot hand in the roll forging machine with a part of the robot hand shown in section.

Fig. 4 is a side view of the robot hand.

Fig. 5 is an explanatory view of showing schematically the roll dies in the roll forging machine.

Fig. 6 is an explanatory view showing routes for movement of the robot hands of the first robot and the second robot.

Fig. 7 is an explanatory view of operation showing relation among the first robot, the second robot and the roll forging machine.

Fig. 8 is an explanatory view 1 showing schematically positional relation between the first robot and the second robot. Fig. 9 is an explanatory view 2 showing schematically positional relation between the first robot and the second robot.

Fig. 10 is an explanatory view 3 showing schematically positional relation between the first robot and the second robot.

Fig. 11 is an explanatory view 4 showing schematically positional relation between the first robot and the second robot.

[Arrangements for Carrying Out the Invention]

[0020]

Arrangements for carrying out the roll forging machine and roll forging method according to the present invention will be explained below.

Fig. 1 is a front view showing an embodiment of a roll forging machine according to the present invention, Fig. 2 is a plan view of the roll forging machine, Fig. 3 is a front view of the robot hand in the roll forging machine with a part of the robot hand shown in section, Fig. 4 is a side view of the robot hand, Fig. 5 is an explanatory view of showing schematically the roll dies in the roll forging machine, Fig. 6 is an explanatory view showing routes for movement of the robot hands of the first robot and the second robot and Fig. 7 is an explanatory view of operation showing relation among the first robot, the second robot and the roll forging machine.

[0021]

Fig. 8 is an explanatory view 1 showing schematically positional relation between the first robot and the second robot, Fig. 9 is an explanatory view 2 showing schematically positional relation between the first robot and the second robot, Fig. 10 is an explanatory view 3 showing schematically positional relation between the first robot and the second robot and Fig. 11 is an explanatory view 4 showing schematically positional relation between the first robot and the second robot.

[0022]

Main body of a roll forging machine

The composition of a roll forging machine 1 will be explained, referring to Figs. 1 to 5. The roll forging machine 1 is composed of a main body 2 of the roll forging machine, a first robot 10 as a first carrying unit, a second robot 30 as a second carrying unit, or the like.

[0023]

A first roll driving axle 3 and a second roll driving axle 5 are held rotatably on the main body 2 of the roll forging machine. The first roll driving axle 3 and the second roll driving axle 5 are provided as forming a paired composition with the axes thereof being parallel each other. Both ends of the first roll driving axle 3 are held on the main body 2 via a bearing (not shown). Similarly, both ends of the second roll driving axle 5 also are held on the main body 2 via a bearing (not shown). The first roll driving axle 3 is driven to be rotated by output transmitted from a servomotor SM via a transmission gear mechanism (not shown). The second roll driving axle 5 is driven to be rotated by output transmitted from a servomotor (not shown but similar to one used for the first roll driving axle 3) via a transmission gear mechanism (not shown). In other words, the first roll driving axle 3 and the second roll driving axle 5, composed as a pair of upper and lower axles, are composed so as to be driven to be rotated by a pair of servomotors SM respectively.

[0024]

Here, the first roll driving axle 3 and the second roll driving axle 5 are usually controlled so as to be rotated and stop simultaneously. Further, the first roll driving axle 3 and the second roll driving axle 5 are usually controlled so as to be rotated in directions opposite to each other (direction R and direction R' in Fig. 5) and at the same rotational rate. A first roll die 4 is fixed detachably on the outer circumferential face of the first roll driving axle 3 and a second roll die 6 is fixed detachably on the outer circumferential face of the second roll driving axle 5.

[0025]

The first roll die 4 has a plurality of shaping dies 4a formed with a certain distance therebetween for performing shaping with dies through roll forging (shaping with a pair of roll dies). The second roll die 6 has a plurality of shaping dies 6a formed with a certain distance therebetween for performing roll forging.

[0026]

Carrying units

As shown in Figs. 1 and 2, a first carrying unit and a second carrying unit for feeding materials m to be shaped to shaping dies 4a and 6a, performing shaping with dies and carrying out articles shaped to have a desired configuration are provided in front of the main body 2 of the roll forging machine. The first carrying unit is a first robot 10 called an articulated robot and the second carrying unit is a second robot 30 called an articulated robot. While the first robot 10 and the second robot 30 are well known in the art as articulated robots that enable three dimensional movement of robot hands, explanation of arrangement will be made here briefly for easier understanding of explanation of this arrangement.

[0027]

First robot

The first robot 10 is a robot of a hung type provided to be hung on a hanging base 7. The hanging base 7, as a base body for hanging, is composed such that an upper plate 73 is fixed on the upper ends of three poles 72 fixed on a base plate 71 and vertically extending respectively.

[0028]

A robot base 11 of the first robot 10 is fixed to the underside face of the upper plate 73. A first turning mechanism 12 is provided between the robot base 11 and a first turning base 13. The first turning base 13 makes turning movement around the axis CI (in the direction by arrow Θ 1) relative to the robot base 11 and is positioned to be in a desired turning position. A first swinging mechanism 14 is provided between the first turning base 13 and a first arm 15. The first arm 15 makes swinging movement around the axis C2 (in the direction of arrow Θ 2) relative to the first turning base 13 and is positioned to be in a desired swinging position. A second swinging mechanism 16 is provided between the first arm 15 and a second arm 17. The second arm 17 makes swinging movement around the axis C3 relative to the first arm 15 in the direction of arrow Θ 3 and is positioned to be in a desired swinging position.

[0029]

A second turning mechanism 18 is provided between the second arm 17 and a third arm 19. The third arm 19 makes turning movement around the axis C4 (in the direction of arrow Θ 4) relative to the second arm 17 and is positioned to be in . ^" 'a desired turning position. A third swinging mechanism 20 is provided between the third arm 19 and a fourth arm 21. The fourth arm 21 makes swinging movement around the axis C5 in the direction of arrow Θ 5 relative to the third arm 19 and is positioned to be in a desired swinging position. A robot hand 25 is attached to the fourth arm 21. In the first robot 10, the first turning mechanism 12, the second turning mechanism 18, the first swinging mechanism 14, the second swinging mechanism 16, the third swinging mechanism 20 or the like are controlled by a first robot control apparatus (not shown) that controls driving and positioning of servomotors (not shown).

[0030]

The second robot 30 is a robot of a floor type. The robot base 31 of the second robot 30 is fixed on the upper face of the base plate place on the floor. A first turning mechanism 32 is provided between the robot base 31 and a first turning base 33. The first turning base 33 makes turning movement around the axis Cll (in the direction of arrow Θ 11) relative to the robot base 31 and is positioned to be in a desired turning position. A first swinging mechanism 34 is provided between the first turning mechanism 33 and a first arm 35. The first arm 35 makes swinging movement around the axis C12 in the direction of arrow Θ 12 relative to the first turning base 33 and is positioned to be in a desired swinging position. A second swinging mechanism 36 is provided between the first arm 35 and a second arm 37. The second arm 37 makes swinging movement around the C13 in the direction of arrow Θ 13 relative to the first arm 35 and is positioned to be in a desired swinging position.

[0031]

A second turning mechanism 38 is provided between the second arm 37 and a third arm 39. The third arm 39 makes turning movement around the axis C14 (in the direction of arrow Θ 14) relative to the second arm 37 and is positioned to be in a desired turning position. A third swinging mechanism 40 is provided between the third arm 39 and a fourth arm 41. The fourth arm 41 makes swinging movement around the axis C15 in the direction of arrow Θ 15 relative to the third arm 39 and is positioned to be in a desired swinging position. A robot hand 45 is attached to the fourth arm 41. In the second robot 30, the first turning mechanism 32, the second turning mechanism 38, the first swinging mechanism 34, the second swinging mechanism 36, the third swinging mechanism 40 or the like are controlled by a second robot control apparatus (not shown) that controls driving and positioning of servomotors (not shown).

[0032]

Robot hand

The robot hand 25 of the first robot 10 and the robot hand 45 of the second robot 30 will be explained, referring to Figs. 3 and 4. Here, the robot hand 25 and the robot hand 45 are of a same composition. So explanation of the arrangement will be made for the robot hand 25 as an example.

[0033]

In the robot hand 25, a robot hand base (referred to as a hand base below) 253 is attached to the fourth arm 21 or the fourth arm 41. A robot hand rotating axle (referred to as a hand rotating axle below) 254 is provided to be supported in a rotatable manner by bearings 255, 255 in the hand base 253. A pair of gripping pawls 251, 251 is provided for gripping a material m to be shaped at the front side of the hand axle 254. A robot hand opening- closing driving unit (referred to as a hand driving unit below) 252 is provided in the back side of the hand axle 254. Connecting rods (not shown) and linkages (not shown) for opening-closing of the hand are provided between the hand driving unit 252 and the pair of gripping pawls 251, 251. The hand driving unit 252 causes the connecting rods to be reciprocated in the lengthwise direction of the hand base 253 (parallel to the axis C6 in Fig. 3). The linkages for opening-closing of the hand convert reciprocation movement of the connecting rods to opening-closing movement of the gripping pawls 251, 251.

[0034]

In other words, the pair of gripping pawls 251, 251 performs opening-closing action with operation of the hand driving unit 252 via the linkages for opening-closing of the hand. Clamping spring (not shown) for retracting the connecting rods backward to cause the pair of gripping pawls 251, 251 make closing movement. A cylinder 252a is provided in the hand driving unit 252 for advancing the connecting rod forward against the clamping spring when pressurized fluid (e. g., pressurized oil) is supplied. The forward advancing movement of the connecting rod by the cylinder 252a causes the pair of gripping pawls 251, 251 to make opening movement via the linkages for opening-closing of the hand. When supply of pressurized fluid to the cylinder 252a is ceased, the clamping spring retracts the connecting rod backward with its stored force. The backward movement of the connecting rod by the clamping spring causes the pair of gripping pawls 251, 251 to make closing movement via the linkages for opening-closing of the hand. The forward and backward movement of the connecting rod by the hand driving unit 252 can be detected by an opening-closing movement detecting portion 252b. Such opening-closing mechanism of the robot hand comprising linkages for opening-closing of the hand, connecting rods or the like is well known in the art, thus explanation of further details are omitted here.

[0035]

A servomotor 261 for rotating and positioning the robot hand (referred to as a servomotor for the rotating axle below) to rotate the hand rotating axle 254 around the axis C6 (in the direction of arrow Θ 6 in Fig. 3) is attached to the hand base 253. A toothed pulley-toothed belt mechanism is provided between the output axle of the servomotor 261 for the rotating axle and the hand rotating axle 254. That is, one toothed pulley is attached to the output axle of the servomotor 261 for the rotating axle and the other toothed pulley 262 is attached to the hand rotating axle 254. A toothed belt is looped over the one toothed pulley and the other toothed pulley 262 to surround them. A robot hand rotating and positioning unit (referred to as a hand rotating unit below) 26 is composed of the servomotor 261 for the rotating axle and the toothed pulley-toothed belt mechanism. With the hand rotating unit provided, roll forging (shaping with a pair of roll dies) can be performed in such a manner where the hand rotating axle 254 turns the direction around the axis C6 by 90 degree, for example. Here, the toothed pulley-toothed belt mechanism may be replaced by another transmission mechanism such as a gear mechanism.

[0036]

A pair of roll dies

Working of shaping with a pair of roll dies 4, 6 (roll forging) will be explained, referring to Figs. 5, 6. In this roll forging machine, the robot hand 25 and the robot hand 45 move along the routes shown in Fig. 6 respectively. On the other hand, in the roll forging machine 1, the first roll die 4 has four shaping dies 4a (4al, 4a2, 4a3 and 4a4) formed thereon and the second roll die 6 has four shaping dies 6a (6al, 6a2, 6a3 and 6a4) formed thereon respectively. The shaping dies 4a and shaping dies 6a compose pairs of shaping dies. Specifically, the shaping die 4al and shaping die 6al compose a first shaping dies Fl, the shaping die 4a2 and shaping die 6a2 compose a second shaping dies F2, the shaping die 4a3 and shaping die 6a3 compose a third shaping dies F3 and the shaping die 4a4 and shaping die 6a4 compose a fourth shaping dies Fl (see Fig. 5).

[0037] Corresponding to this, the first robot 10 and the second robot 30 cause the robot hand 25 and the robot hand 45 to move to a first step position P2 corresponding to the first shaping dies Fl, to a second step position P3 corresponding to the second shaping dies F2, to a third step position P4 corresponding to the third shaping dies F3 and to a fourth step position P5 corresponding to the fourth shaping dies F4, respectively. For example, the roll forging machine 1 shapes the material to be shaped into a desired form with the shaping dies Fl comprising shaping die 4al and the shaping die 6al in the first step position P2. In other words, working of roll forging (shaping with a pair of dies) is performed on the material m to be shaped that is gripped by the pair of gripping pawl 251, 251 provided on the robot hands 25, 45 respectively with the first roll die 4 rotated in the direction R shown in Fig. 5 and the second roll die 6 rotated in the direction R'.

[0038]

These first shaping dies Fl, second shaping dies F2, third shaping dies F3 and fourth shaping dies F4 are generally used as follows. With the first shaping dies Fl in the first step position P2, the material m to be shaped is pressed. With the second shaping dies F2 in the second step position P3, corrective shaping is performed on the widened portion of the material m to be shaped pressed with the shaping dies Fl after rotating the pressed material around the axis C6 by 90 degrees with the hand rotating unit 26. With the third shaping dies F3 in the third step position P4, the material m to be shaped is rotated reversely around the axis C6 by 90 degrees by the hand rotating unit 26 and is pressed. With the fourth shaping dies F4 in the fourth step position P5, corrective shaping is performed on the widened portion of the material m to be shaped pressed with the shaping dies F3, thus forming a final shaped article that has a final form with a thin concave and convex along with substantially circular cross section.

[0039]

Roll forging method

A roll forging method using the roll forging machine 1 will be explained referring to Figs. 6 to 11. The first roll die 4 and the second roll die 6 are rotated at a predetermined rotational frequency. Also, rotation of the first roll driving axle 3 and the second roll driving axle 5 is controlled by a servomotor SM and the rotational positions of them are synchronized.

[0040] As shown in Fig. 6, a first route for movement 50A is formed such that the robot hand 25 of the first robot 10 moves so as to take the following positions sequentially: a receiving position of a material m to be shaped PI (referred to as a receiving position below) for receiving a material m to be shaped that has been heated to a determined temperature from the feeding unit of materials to be shaped (not shown), a first step position P2, a second step position P3, a third step position P4, a fourth step position P5, a position for carrying out the shaped article P6 for carrying out the shaped article onto a shaped article carrying out unit 8 (referred to as a carrying out position below), a position for turning aside P7 and a position before receiving a material to be shaped P8 (referred to as a position before receiving below). The first step position P2, the second step position P3, the third step position P4 and the fourth step position P5 are disposed in line and form a route for movement in shaping 51 for shaping the material m to be shaped. The receiving position PI and the carrying out position P6 are disposed in the extension of the route for movement in shaping 51. That is, the robot hand 25 moves along the first route for movement 50A with a box-shaped (closed-loop) form including the route for movement, which includes the route for movement in shaping 51 comprising the first step position P2, the second step position P3, the third step position P4 and the fourth step position P5 and in which the receiving position PI to the carrying out position P6 through are disposed in line, and also including a first route for turning aside 52 which is spaced apart from the route for movement in shaping 51 by a predetermined distance on one side (e.g. on the lower side in the shown arrangement).

[0041]

A second route for movement 50B is formed such that the robot hand 45 of the second robot 30 moves so as to take the following positions sequentially: the receiving position PI, the first step position P2, the second step position P3, the third step position P4, the fourth step position P5, the carrying out position P6, a position for turning aside P17 and a position before receiving a material to be shaped P18 (referred to as a position before receiving below). That is, the robot hand 45 moves along the second route for movement 50B with a box-shaped (closed-loop) form including the route for movement, which includes the route for movement in shaping 51 comprising the first step position P2, the second step position P3, the third step position P4, the fourth step position P5 and in which the receiving position PI to the carrying out position P6 through are disposed in line, and also including a second route for turning aside 53 which is spaced apart from the route for movement in shaping 51 by a predetermined distance on the other side (e.g. on the upper side in the shown arrangement).

[0042]

The movement of the first robot 10 and the second robot 30 will be explained, relating these with the movement on the side of the main body 2 of the roll forging machine 1. On the side of the main body 2 of the roll forging machine 1, the first roll driving axle 3 and the second roll driving axle 5 are rotated at a determined rotational frequency. Further explanation will be made referring to the "flow chart of movement and operation" shown in Fig. 7.

The robot hand 25 of the first robot 10 moves from the third step position P4 to the fourth step position P5. At this time, the robot hand 45 of the second robot 30 moves from the position before receiving P18 to the receiving position PI (see Fig. 9). The first robot 10 performs shaping with the fourth shaping dies F4 after the robot hand 25 has moved to the fourth step position P5. The second robot 30 receives the material m to be shaped from the feeding unit of materials to be shaped in the receiving position PI with the robot hand gripping the material. (Step Si)

[0043]

The robot hand 45 of the second robot 30 that has received the material m to be shaped moves from the receiving position PI to the first step position P2. At this time, the robot hand 25 of the first robot 10 moves from the fourth step position P5 to the carrying out position P6, releases gripping of the shaped article and transfers it to the shaped article carrying out unit 8. The second robot 30 performs shaping of the material m to be shaped gripped by the robot hand 45 with the first shaping dies Fl after the robot hand 45 has moved to the first step position P2. (Step S2)

The robot hand 45 of the second robot 30 moves from the first step position P2 to the second step position P3. At this time, the robot hand 25 of the first robot 10 moves from the carrying out position P6 to the position for turning aside P7. The second robot 30 performs shaping of the material m to be shaped gripped by the robot hand 45 with the second shaping dies F2 after the robot hand 45 has moved to the second step position P3. (Step S3) [0044]

The robot hand 45 of the second robot 30 moves from the second step position P3 to the third step position P4. At this time, the robot hand 25 of the first robot 10 moves from the position for turning aside P7 to the position before receiving P8 (see Fig. 10). The second robot 30 performs shaping of the material to be shaped gripped by the robot hand 45 with the third shaping dies F3 after the robot hand 45 has moved to the third step position P4. (Step S4)

[0045]

The robot hand 45 of the second robot 30 moves from the third step position P4 to the fourth step position P5. At this time, the robot hand 25 of the first robot 10 moves from the position before receiving P8 to the receiving position PI (see Fig. 11). The second robot 30 performs shaping of the material m to be shaped gripped by the robot hand 45 with the fourth shaping dies F4 after the robot hand 45 has moved to the fourth step position P5. The robot hand 25 of the first robot 10 receives a material m to be shaped from the feeding unit of materials to be shaped. (Step S5)

[0046]

The robot hand 45 of the second robot 30 moves from the fourth step position P5 to the carrying out position P6. At this time, the robot hand 25 of the first robot 10 moves from the receiving position PI to the first step position P2. The first robot 10 performs shaping of the material m to be shaped gripped by the robot hand 25 with the first shaping dies Fl after the robot hand 25 has moved to the first step position P2. The second robot 30 releases gripping by the robot hand 45 and hands over the shaped article to the shaped article carrying out unit 8 in the carrying out position P6. (Step S6)

[0047]

The robot hand 25 of the first robot 10 moves from the first step position P2 to the second step position P3. At this time, the robot hand 45 of the second robot 30 moves from the carrying out position P6 to the position for turning aside P17. The first robot 10 performs shaping of the material m to be shaped gripped by the robot hand 25 with the second shaping dies F2 after the robot hand 25 has moved to the step position P3. (Step S7)

[0048]

The robot hand 25 of the first robot 10 moves from the second step position P3 to the third step position P4. At this time, the robot hand 45 of the second robot 30 moves from the position for turning aside P17 to the receiving position P18 (see Fig. 8). The first robot 10 performs shaping of the material m to be shaped gripped by the robot hand 25 with the third shaping dies F3 after the robot hand 25 has moved to the third step position P4. (Step S8)

Returning to Step SI, operation of shaping with the shaping dies on materials to be shaped is repeated.

[0049]

Here, while aforementioned explanation of the arrangement regarding Fig. 6 is made with an example such that the receiving position PI, the first step position P2, the second step position P3, the third step position P4, the fourth step position P5 and the carrying out position P6 are disposed in line, the receiving position PI and the carrying out position P6 need not necessarily be disposed in the extension of the route for movement in shaping 51. For example, the receiving position PI and/or the carrying out position P6 may be disposed on the first route for turning aside or the second route for turning aside. Further, the receiving position PI and/or the carrying out position 8P6 may be disposed in the middle between the route for movement in shaping and the first route for turning aside or the second route for turning aside.

[0050]

In other words, such a composition may be possible that the robot hand 25 of the first robot 10 and the robot hand 45 of the second robot 30 do not perform shaping simultaneously coexisting on the route for movement in shaping 51 extending over the first step position P2, the second step position P3, the third step position P4 and the fourth step position P5.

[0051]

With this roll forging machine 1, the pair of roll dies 4 and 6 fixed to the pair of roll driving axles 3 and 5 respectively are caused to be rotated constantly and the first robot 10 and the second robot 30 are operated in rotation one after another so as to perform working of shaping (roll forging) with the pair of roll dies 4 and 6. Consequently, with this roll forging machine 1, shaping with the pair of roll dies 4 and 6 do not stop in receiving the material m to be shaped and handing over the shaped article, thus attaining improvement of productivity. For example, when the robot hand 25 of the first robot 10 (or the robot hand 45 of the second robot 30) is in the receiving position PI, the robot hand 45 of the second robot 30 (or the robot hand 25 of the first robot 10) is in the fourth step position P5. Further, when the robot hand 25 of the first robot 10 (or the robot hand 45 of the second robot 30) is in the carrying out position P6, the robot hand 45 of the second robot 30 (or the robot hand 25 of the first robot 10) is in the first step position P2. In such a manner, the robot hand 25 of the first robot 10 and the robot hand 45 of the second robot 30 do not interfere with each other as well as shaping with the roll die 4 and the roll die 6 at all times, thereby allowing improvement of productivity.

[0052]

Also, the first robot 10 and the second robot 30 are controlled such that the robot hand 45 of the second robot 30 moves along the route for movement including the second route for tuning aside 53 except the route for movement in shaping 51 of the second route for movement 50B when the robot hand 25 of the first robot 10 moves along the route for movement in shaping 51 of the first route for movement 50A and performs working of shaping in the positions from the first step position P2 to the fourth step position P5. On the other hand, the first robot 10 and the second robot 30 are controlled such that the robot hand 25 of the first robot 10 moves along the route for movement including the first route for tuning aside 52 except the route for movement in shaping 51 of the first route for movement 50A when the robot hand 45 of the second robot 30 moves along the route for movement in shaping 51 of the second route for movement 50B and performs working of shaping in the positions from the first step position P2 to the fourth step position P5. The first route for turning aside 52 for the first robot 10 and the second route and the second route for turning aside 53 for the second robot 30 are provided such that they are spaced apart by a predetermined distance upward or downward (as shown) from the route for movement in shaping 51 respectively.

[0053]

The predetermined distance of the first and second routes for turning aside 52 and 53 from the route for movement in shaping 51 are to be set as follows. As shown in Fig. 6, the distance from the first route for turning aside 52 to the route for movement in shaping 51 is LI and the distance from the second route for turning aside 53 to the route for movement in shaping 51 is L2, respectively. Let the maximum radiuses of the robot hands 25 and 45 of the first robot 10 and 30 be Rl and R2, respectively. In order to avoid interference between the robot hand 25 of the first robot 10 moving along the first route for turning aside 52 and the robot hand 45 of the second robot hand 45 of the second robot 30 moving along the route for movement in shaping 51, the distance Ll must be larger than R1+R2 by a certain amount Dl. This certain amount Dl is determined to securely avoiding interference between the two robot hands.

[0054]

Also, the case in which the robot hand 25 of the first robot 10 moves along the route for movement in shaping 51 and the robot hand 45 of the second robot 30 moves along the second route for turning aside 53 is considered similarly and the distance L2 must be must be larger than Rl +R2 by a certain amount D2. The amount of margin Dl and D2 may be taken as substantially the same. By setting the distance Ll, L2 from the routes for turning aside 52, 53 to the route for movement in shaping 51 so as to avoid interference between the two robot hands as above, the robot hand 25 of the first robot 10 and the robot hand 45 of the second robot 30 can move without interfering with each other.

[0055]

The necessity of avoiding interference between the robot hand 25 of the first robot 10 and the robot hand 45 of the second robot 30 is explained above. Further, regarding two articulated robots, it is required to avoid interference between the arms of both robots. To attain this, regarding the first robot 10 and second robot 30 of articulated type, movement of the arms composing both articulated robots need to be controlled so as not to interfere with each other. That is, conditions of movement of the robot arms, such as angles of swinging or turning of the arms, timing of such movement, or the like should be set to satisfy the requirement of avoid interference between the robot arms during the operation of the robots for performing roll forging and movement related to this.

[0056]

With this roll forging machine 1, it is possible for the first robot 10 and the second robot 30 to perform alternately shaping with the pair of roll dies 4 and 6 rotated constantly, thus improving productivity. For example, the robot hand 45 of the second robot 30 (or the robot hand 25 of the first robot 10) moves from the fourth step position P5 to the carrying out position P6 when the robot hand 25 of the first robot 10 (or the robot hand 45 of the second robot 30) moves from the receiving position PI to the first step position P2. In such a manner, the robot hand 25 of the first robot 10 and the robot hand 45 of the second robot 30 can move without interfering with each other and perform shaping with the pair of dies 4 and 6 at all times.

[0057]

Further, two robots 10 and 30 are operated in rotation in this roll forging machines 1. For this sake, the time for feeding the materials to be shaped and the time for carrying out the shaped articles, which were loss times for the conventional roll forging machine, are not loss times for this roll forging machine 1. This roll forging machine has a composition in which two robot hands 25 and 45 are disposed in upper and lower positions (as shown) respectively and interference between them can be avoided, so that rotational operation of the two robots 10 and 30 can be attained. For this sake, improvement of productivity by this roll forging machine can be attained.

[0058]

Moreover, while two sets of roll dies were required for improving productivity with a conventional roll forging machine, this roll forging machine does not require two sets of roll dies. For this sake, this roll forging machine enables reduction in expense of die fabrication, reduction in area of die preservation space and shortening the time for die exchange, which brings economical merits.

[0059]

With the roll forging machine 1 controlled in such a manner, cycle time can be shortened and temperature variation in the material to be shaped decreases, thus improvement of product quality can be attained. Further, rotation can be of same direction so that the direction of applied load is same with this roll forging machine 1, thus lifetime of the product by the roll forging machine 1 can be improved compared with the roll forging machine in which rotation is made both in one direction and in the other direction. Furthermore, successive shaping can be made with same roll dies, thus variation of form can be restrained and quality of products can be improved.

[0060] The roll forging method by the roll forging machine is such that roll forging is performed through controlling two robots in a manner in which, when the robot hand of one robot moves along the route for movement in shaping, the robot hand of the other robot moves along the route for movement including the first route for turning aside or the second route for turning aside except the route for movement in shaping. With this roll forging method, the robot hands 25 and 45 of both robots perform roll forging (shaping with a pair of dies) feeding materials to be shaped to the roll dies 4 and 6 alternately without interference of the robot hands with each other, so that improvement of productivity can be attained.

[0061]

While embodiments of the present invention has been explained above, it goes without saying that the present invention is not restricted to such embodiments. For example, the carrying unit may be a robot of orthogonal coordinate type or the like that can move in three axis directions. That is, it may be such a carrying unit that can control movement of the robot hand in three dimensional directions. With a composition in which movement in the direction orthogonal to the horizontal plane beside movement in the horizontal plane is possible, such a carrying unit can be composed that, when one robot hand is in a position from the first step position to the fourth step position moving along the route for movement in shaping, the other robot hand can be controlled so as to move along the route for movement except the route for movement in shaping (the first route for turning aside or the second route for turning aside) and interference of two robot hands with each other can be avoided. Further, the articulated robot may be one having another composition or with another number of axes, thus enabling such composition with which movement of robot hands can be controlled in three dimensional directions.

[0062]

Further, while the above explanation of embodiments has been made for the example of a pair of roll dies having four shaping dies formed on each roll die, the pair of roll dies may be ones on which a plurality of dies (e. g. two or six shaping dies) are formed. Also, while the embodiments has been made for the example in which working of shaping is performed through four steps, working of shaping may be performed through six steps or two steps or another number of steps if articles can be shaped. [0063]

Moreover, while explanation of the embodiments has been made regarding an example of carrying units comprising a robot of a hung type (a carrying unit) and a robot of a floor type (a carrying unit), a composition may be considered in which two carrying units of a floor type are provided on planes for mounting them (floors) with a height difference therebetween. For example, with a first floor plane for mounting one carrying unit, a bottom plane of a pit dug down below the first floor plane by a determined amount may be taken as a second floor plane for mounting the other carrying unit, thus mounting the other carrying unit on the plane for mounting in the pit.

[Explanation of reference notation]

[0064]

1 roll forging machine

2 main body of roll forging machine

3 first roll driving axle

4 first roll die

5 second roll driving axle

6 second roll die

7 hanging base

8 shaped article carrying out unit

10 first robot

11, 31 robot base

12, 32 first turning mechanism

13, 33 first turning base

14, 34 first swinging mechanism

15, 35 first arm

16, 36 second swinging mechanism

17, 37 second arm

18, 38 second turning mechanism

19, 39 third arm

20, 40 third swinging mechanism

21, 41 fourth arm

25, 45 robot hand

251, 251 a pair of gripping pawls 252 robot hand driving unit

252a cylinder

253 robot hand base

254 robot hand rotating axle

26 robot hand rotating and positioning unit

261 servomotor

30 second robot

31 second robot base

50A first route for movement

50B second route for movement

51 route for movement in shaping

52 first route for turning aside

53 second route for turning aside

PI receiving position of a material to be shaped

P2 first step position

P3 second step position

P4 third step position

P5 fourth step position

P6 position of carrying out a shaped article

P7, P17 position for turning aside

P8, P18 position before receiving a material to be shaped