BACKGROUND ART Generally, a grinding machine grinds a blade of a tool when the blade is worn away by using the tool mounted on a machine, or before a new tool is mounted on the machine. In a conventional grinding machine, a feed board of a machine body is moved frontward, backward, leftward and rightward, and a rotation portion for rotating a chuck holder for holding the tool is disposed on the feed board. The blade of the tool is ground by moving and rotating the chuck holder so that the tool reaches an optimal grinding position of an object placed on the grinding portion. However, in order to grind the tool with the above method, a grinding angle is adjusted using a skilled technique of a worker for a series of task processes for rotating the chuck holder holding the tool relative to the object so that the tool maintains a proper grinding angle.

Accordingly, there are problems that an angle of the ground blade of the tool is not correct on a certain surface and working efficiency is degraded.

Particularly, there is another problem that if grinding cause an incorrect angle of the blade as in an end mill, a surface is erroneously machined when the tool is mounted on the machine, resulting in an increased failure rate of a product.

DISCLOSURE OF THE INVENTION The present invention has been made to solve the aforementioned

problems, and it is an object of the present invention to provide a tool grinding machine wherein a hinge is formed at the center of a body of a chuck holder and a slope scale plate is attached to a top of the hinge, such that an angle of a under blade of a tool such as an end mill is accurately ground, and the first and second angles of the peripheral cutting blade of the tool is simultaneously ground using an angle adjustment lever in an end of the chuck holder ; and in an angle scale plate at a rotation portion, a measurement block gauge is adhered to a sin value of a desired angle on a basis of a fixed block gauge, thereby accurately grinding the under blade of the tool and the first and second angles of the peripheral cutting blade.

It is another object of the present invention to provide a tool grinding machine wherein a grinding body is divided into upper and lower portions so that the upper body rotates in a desired angle, and at the same time, an angle scale plate is formed so that a worker checks up the angle in a rotation state, thereby forming a spherical angle of the tool.

The present invention for achieving the objects is characterized in that a tool grinding machine comprises: a feed handle A at an end of a workable A in a body, for rotating a screw bar inside the workable A so that a workable B is moved leftward and rightward; a locking lever at the lower side of the workable B, for releasing or holding the workable B from and to the workable A; a knob at front of the workable A, the knob having a spur gear engaged with a rack gear formed in both ends of the workable B so that the workable B is moved frontward and backward; front and back block gauges in the guide groove formed at the side of the workable B, for setting a grinding travel distance value of the tool after the locking lever is released; a workable A between the front and back block gauges, the workable having a fixed

stopper for braking the tool after the grinding travel distance value of the tool is set by the worktable B ; a feed handle B at the back of the worktable B for moving the workable B over the workable A frontward and backward; a fixed angle scale plate at a rotational portion positioned on the workable B such that a value of a under blade grinding angle of the tool is checked up by the eyes; a stationary block gauge on the angle scale plate for allowing a grinding angle of the first and second angles of the peripheral cutting blade of the under blade of the tool to be ground by a sin value, and another stationary block gauge being adhered to the sin value by using as a reference the stationary block gauge; a workable D over a workable C held to the rotation portion, having a center gauge for setting a horizon with a center of the tool, a bar of 20 mm under the workable C being 0° of the sin value, and a lower guide groove in the guide protrusion having a wide top and a narrow bottom over the workable C so that the tool is ground by moving frontward and backward; a workable E with a lower guide groove at a guide protrusion having a wide top and a narrow bottom over the workable D so that the tool is ground by moving leftward and rightward; a chuck holder on a hinge shaft of the workable E for holding the tool ; a slope scale plate indicated at a upper side of the chuck holder so that a slope of the chuck holder is checked up after a bolt engaged with the hinge shaft is released ; an angle adjustment lever at a back of the chuck holder, the angle adjustment lever having an indicated angle scale plate returning in a reverse rotation by elasticity of a pressed plate spring, which is pressed by counterclockwise rotating the plate spring that is elastically disposed inside the chuck holder ; a bushing engaged with a bolt on a shaft inside the chuck holder, the bolt being engaged with a screw hole punched into one end of the plate spring, a bolt engaged with a circular clip

being engaged with a screw hole punched into the other end of the plate spring; a spring pressed bolt in a plurality of clip grooves, which are formed on a peripheral surface of the circular clip, for braking a rotation of the circular clip ; and a detachable lever at a upper center of the chuck holder, the lever having a protrusion at an end of the lever so that it is detachable to a 15° division plate disposed on a shaft of the chuck holder.

Moreover, the present invention is characterized in that a tool grinding machine comprises: a relief angle adjustment portion under a grinding portion disposed on a side of a workable A in a body, for allowing a relief angle of a under blade of a tool to be ground; a movable rotational piece and a stationary piece fixed to the workable A, at front of the relief angle adjustment portion; a plurality of bolts at the back of the relief angle adjustment portion, for allowing the rotational piece to be moved and stopped; a rack gear and a spur gear inside the rotational piece and a stationary piece, for allowing the rotational piece to be rotated by release of the bolt, the rack gear being in the rotational piece and the spur gear being in the stationary piece; and a relief angle scale plate at front of the stationary piece for allowing a rotation angle of the rotational piece to be checked up.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: Fig. 1 is a perspective view of the present invention; Fig. 2 is a side view of the present invention; Fig. 3 is a schematic front view showing an operation state of a feed

handle A for horizontally moving a work table B, and a grinding portion according to the present invention; Fig. 4 is an internal disassembled perspective view of a chuck holder of the present invention; Fig. 5 is an extracted perspective view of an angle division plate, which is a main part of the present invention ; Fig. 6 is a schematic view showing an operation state of a detachable lever of the present invention: (a) shows the operation state when a detachable lever is downward, and (b) shows the operation state when the detachable lever is upward; Fig. 7 is a front view showing an operation state of a spring pressed bolt applied to the present invention; Fig. 8 is a side view of a center gauge applied to the present invention; Fig. 9 is a schematic front view showing a vertical cross state of a grinding portion and a tool of the present invention: (a) shows a state before both contact each other, (b) shows formation of a first peripheral cutting angle of 6° of the tool, and (c) shows a formation of the second peripheral cutting angle of 15° of the tool P ; Fig. 10 is a view showing an operation state of a locking lever applied to the present invention; Fig. 11 is a side-sectional view showing an operation state of a chuck holder of the present invention;

Fig. 12 is a plan view showing an operation state of a stationary block gauge by sin measurement of the present invention: (a) shows a plane trigonometric function, (b) shows a state in which a stationary block gauge is adhered to a center ball after an angle of 0° is fitted by a dial gauge, and (c) shows an operation state of the stationary block gauge after an angle of 0° is fitted by a dial gauge rotated 90° ; Fig. 13 is a perspective view of a fixed groove of a bite showing another embodiment of the present invention; and Fig. 14 is a side-sectional view.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

A grinding whetstone 21, which is driven by a driving motor (not shown), is disposed on a shaft end of a grinding portion 20 in a body 10. A relief angle adjustment piece 22 positioned under the grinding portion 20 is divided into a upper rotational piece 23 and a lower stationary piece 24, wherein a relief angle scale plate 24a is formed in an arc shape in front of the stationary piece 24 and a plurality of bolts 24b are engaged with the back of the stationary piece 24, in which the bolts can hold the rotational piece 23 after a value of a relief angle of the rotational piece is set by releasing the rotational piece 23. Between the rotational piece 23 and the stationary piece 24, a rack gear 23a is formed in an arc shape in the rotational piece 23 and a spur gear 24c is formed in the stationary piece 24, so that the rotational piece 23 is rotated when the bolt 24b is released.

A screw bar 32 is integrally connected to a feed handle A 31 placed at an end of a workable A 30 in the body 10. This screw bar 32 is engaged with a lower screw groove 41 of the workable B 40 positioned over the workable A 30 so that the workable B 40 moves leftward and rightward. A locking lever 42 is formed under a side of the workable B 40 to hold or release the workable B 40 to and from the workable A 30. A spur gear 33' of a two-side knob 33 fixed to the back of the workable A 30 is engaged with the rack gear 43 formed at an end of the workable B 40. Front and back block gauges 45 and 45'are inserted into a guide groove 44 formed at the side of the workable B 40 in order to set a travel distance value within which the tool P can be ground, and then to grind it within the set value after frontward and backward movements of the workable B 40 are allowed by releasing the locking lever 42. Also, a stopper 34 is positioned on the workable A 30 between the front and back block gauges 45 and 45'.

A screw bar 46'is integrally connected to a feed handle B 46, which is formed at the back of the workable B 40. This screw bar 46'is engaged with a nut 35 of the workable A 30 so that the workable B 40 moves frontward and backward upon rotation of the feed handle B 46.

A fixed angle scale plate 51 is indicated in a circular shape at the rotational portion 50 disposed on the workable B 40 so that a grinding angle value of the under blade of the tool P is checked up by the eyes. A fixed block gauge 52 is positioned on the angle scale plate 51 so that the under blade and the first and second angles of the peripheral cutting blade of the tool are ground by a sin value. Also, another fixed block gauge 52'with a center angle on the same line is positioned.

A center gauge 61 for setting horizon with the tool center stands on the

workable C 60 positioned over the rotational portion 50. A bar 62 of 20mm corresponding to a sin value of 0° is inserted under the workable C 60. A guide groove 71 formed under the workable D 70 is engaged with a guide protrusion 63 having a wide top and a narrow bottom on the workable C 60.

A screw bar 73 of the angle adjustment lever 72 positioned at the workable D 70 is engaged with a screw groove 64 formed on the workable C 60 so that the workable D 70 moves frontward and backward. A guide groove 81 of a workable E 80 positioned at the upper workable D 70 is engaged with a guide protrusion 74 having a wide top and a narrow bottom on the workable D 70.

The screw bar 83 of an angle adjustment lever 82 positioned at the workable E 80 is engaged with a screw groove 75 of the workable D 70 so that the workable E 80 moves leftward and rightward. A chuck holder 90 inserted into a hinge shaft 84'is positioned at a side plate 84 stood on the workable E 80.

The slope scale plate 91 indicated on an upper side of this chuck holder 90 is formed such that a under blade slope of the fixed tool P is checked up by releasing a bolt 85 engaged with the hinge shaft 84'and then adjusting a slope of the chuck holder 90. An angle scale plate 93'is indicated on the angle adjustment lever 93 positioned at the back of the chuck holder 90. The angle adjustment lever 93 is disposed on the shaft 94, and a bolt 96 is engaged with a busing 95 disposed at the peripheral surface of the shaft 94. This bolt 96 is engaged with a screw hole 97a punched in a side end of the plate spring 97, and a bolt 99 engaged with a circular clip 98 is engaged with a screw hole 97b punched in another end of the plate spring 97.

A plurality of clip grooves 98'is formed at the peripheral surface of the circular

clip 98 so that it contacts and deviates to and from the end of the spring pressed bolt 100. A spring S is elastically disposed on a shaft 101 a of the detachable lever 101 positioned at the center of the chuck holder 90. A protrusion 101b of the detachable lever 101 is detached to a protrusion 102 of the chuck holder 90. A lower end of the shaft 101 a is connected and disconnected to and from a division plate 103 divided at 15° intervals, and the division plate 103 is disposed on the shaft 94.

Moreover, the chuck holder 90 and the side plate 84 on the workable E 80 are released and a bite 120 is disposed at that position. A side plate 121 of the bite 120 is stood on the workable E 80. A boss 123a of the bite holding piece 123 and a block 124 are engaged in a hole 122 of a track type punched in the side plate 121 by a bolt 125. Screw holes 121a and 124', with which a height bolt 126 is engaged, are punched in the side plate 121 and the upper portion of the block 124. Bolts 128 for holding the bite 127, which is inserted in the bite inserting hole 123c, are engaged with the screw holes 123b punched in the upper portion of the bite holding piece 123. A height scale 121 b is indicated on a side of the side plate 121 so that the height is checked up when the bite holding piece 123 moves upward and downward.

A rotation angle scale 123d is indicated on a side of the bite holding piece 123 so that a rotation angle of the bite holding piece 123 is checked up.

Embodiments of the present invention configured as above are as follows : [A first embodiment] (A case of grinding the first and second relief angles in a under blade of a tool)

A chuck holder 104 in the workable E 80 is moved to a vertical cross point with a grinding whetstone 21 positioned on the grinding portion 20. If a feed handle A 31 at an end of the workable A 30 is rotated, a screw bar 32 connected to the feed handle A 31 is rotated. This screw bar 32 is engaged with a nut 41 under the workable B 40 such that the workable B 40 moves horizontally.

If a chuck holder 104 in a workable E 80 and a grinding whetstone 21 are crossed vertically by a movement of the workable B 40, a tool P is inserted and held into the chuck holder 104 and then a horizon is set with a center of the tool P using a center gauge 61 on the workable C 60.

Subsequently, if the locking lever 42 under the workable B 40 is released so that a tool grinding task is effected by advancing the chuck holder 90, the workable B 40 is freely kept from the workable A 40.

If a driving motor (not shown) inside the grinding portion 20 is activated, an operation of the grinding portion 20 for grinding the under blade of the tool drives the grinding whetstone 21 disposed on the shaft thereof.

If a feed handle B 46 at the back of the workable B 40 is rotated clockwise after an initial task for grinding a relief angle of the under blade of the tool P is completed as described above, the workable B 40 moves frontward since the screw bar 46'integrally disposed with the feed handle B 46 is engaged with a screw groove 35 under the workable A 30, and at the same time, the workable B 40 is advanced in horizon since the rack gear 43 at an end of the workable B 40 is engaged with the spur gear 33'formed in the workable A 30. Also, if the under blade of the tool P advances to contact the grinding whetstone 21, then the locking lever 42 in the workable B 40 is switched to a lock state to hold the workable B 40 such that the first relief

angle of the under blade of the tool is ground.

If the bolt 85 at the side of the workable E 80 is released to grind the first relief angle of the under blade of the tool P as described above and then to grind the second relief angle of the under blade of the tool P as a next step, a chuck holder 90 disposed to a hinge shaft 84 is freely slanted about the hinge shaft 84 frontward and backward. (frontward and backward maximum slope angles of the chuck holder are 20°.) The angle of the chuck holder 90 is selected within 20° and then the bolt 85 is again screwed to hold the chuck holder 90. The workable B 40 moves frontward by rotating the feed handle B 46 clockwise as described above, and at the same time, if the under blade of the tool P contacts the grinding whetstone 21 by simultaneously advancing the workable C 60, the workable D 70, the workable E 80, and the chuck holder 90 over the workable B, the locking lever 42 is switched to a lock state to hold the tool P such that the second relief angle is ground in that state.

[A second embodiment] (A case of grinding the first and second angles of the peripheral cutting blade of the tool) This embodiment is the same as the first embodiment in that the chuck holder 104 in the workable E 80 is moved to a vertical cross point with the grinding whetstone 21 positioned on the upper grinding portion 20, and a horizon with a center of the tool P is set using the center gauge 61 on the workable C 60, as previously described.

However, because an end position of the tool P, which has moved to the vertical cross point, is a grinding start point of the under blade, a back

block gauge 45'in the guide groove 44 at the side of the workable B 40 is moved and held to that position, such that the stopper 34 prevents further deviation when the workable B 40 moves backward.

Meanwhile, it is required that the workable B 40 is reciprocated frontward and backward on the table A and at the same time, a reciprocating travel distance of the workable B 40 is set according to a grinding length t of the first and second angles of the peripheral cutting blade of the tool P. An end of the guide bar 25 disposed over the grinding portion 20 is positioned at an end of the peripheral cutting blade of the tool P, and a feed handle B 46 at the back of the workable B 40 is rotated, such that the workable B 40 advances, and the guide bar 25 placed at the end of the peripheral cutting blade of the tool P reaches the end of the blade groove while moving downward along an blade groove P-1 of the tool P.

This start point is an end point of the peripheral cutting blade, and a front block gauge 45 in the guide groove 44 at the side of the workable B 40 is moved and fixed, so that the workable B 40 is any more deviated by the stopper 34 when the workable B 40 advances.

Meanwhile, normally, the first peripheral grinding angle of the tool P has a reference of 6°. An order of setting 6° is as follows : First, if the end of the guide bar 25 is positioned at the end of the peripheral cutting blade of the tool P and the spring pressed bolt 97 in the chuck holder 90 is moved downward rightward, a lower portion of the bolt contacts a plurality of clip grooves 98'formed at the peripheral surface of the circular clip 98. At this time, the circular clip 98 cannot be rotated by the spring pressed bolt 99, and also the bolt 99 on the circular clip 98 is engaged with the plate spring 97, which is elastically pressed by an angle adjustment

lever 93 as described below. That is, if the angle adjustment lever 93 in the chuck holder 90 is rotated counterclockwise, a shaft 94 inside the chuck holder 90 is rotated and at the same time, a bolt 96 fixed to the shaft 94 decompress the plate spring 97.

If the worker lets the angle adjustment lever 93 go after the plate spring 97 is compressed as above, the angle adjustment lever 93 returns clockwise by elasticity of the plate spring 97 and at the same time, the tool P fixed to the chuck holder 104 is also reversely rotated. Accordingly, the guide bar 25 at the end of the peripheral cutting blade of the tool P rises by the elastically disposed internal plate spring (not shown).

If the angle scale plate 93'indicated on the angle adjustment lever 93 is rotated by 6° during the reverse rotation, the reverse rotation of the angle adjustment lever 93 is stopped by the worker, and the height adjustment lever 25'of the guide bar 25 is adjusted. Accordingly, the first angle is set at the end of the peripheral cutting blade of the tool P, such that grinding starts with 6°.

With the same method described above, normally, 15'of the second angle can be set.

After the first peripheral cutting blade is set and a reciprocal release distance t for grinding the tool P is set, a guide bar 25 is positioned at the end of the peripheral cutting blade of the tool P, and the plate spring 95 is decompressed by rotating angle adjustment lever 93 of the chuck holder 90 counterclockwise. The worker lets the angle adjustment lever 93 go after driving the grinding whetstone 21 of the grinding portion 20, the shaft 94 is rotated by elasticity of the plate spring 95 and at the same time, the tool P at an end of the shaft 94 is rotated. At this time, a guide bar 25 in a peripheral

cutting blade end of the tool P is vertically downward along the blade groove, and the tool P, which contacts a grinding whetstone 21, advances with the rotation, and at the same time, the chuck holder 90 moves.

In addition, when the workable B 40 advances frontward, a block gauge 45'in a guide groove 44 at the side of the workable B 40 is braked by the stopper 34, resulting in stop of the workable B 40.

The workable B 40 moves backward as the worker rotates clockwise the feed handle B 46 in the workable B 40. If a block gauge 45 in the guide groove 44 at the side of the workable B 40 is braked by the stopper 45"due to the backward movement of the workable B 40, the workable B 40 is stopped. Accordingly, the first angle of the peripheral cutting blade of the tool P can be ground several times in the same method.

[A third embodiment] (A grinding method by sine of the tool) A sine method by a sine function in a plane is accomplished by a basic manner as shown in Fig. 12a.

That is, assuming that a coordinate system with an origin of a zero in the plane is defined, a coordinate of a point on the plane is denoted as (x, y), a cross point with a unit circle having a center of zero when a line OP is drawn, which forms an angle 0 relative to a positive direction of x axe, is P, and a coordinate of P is (x, y), x and y are defined each time 0 is given. At this time, a function 0-y refers to a sine function, which is represented by y=sin A.

A grinding method according to the present invention using a sin value by a sine function as above will be described with reference to Figs. 12b and 12c. First, in order to form a coordinate system with an origin of 0 in a plane

on the workable D 70, after a typical dial gauge (not shown) is placed and then the workable D 70 is fitted to 0°, a movement of the workable D 70 is suppressed by screwing a bolt 53 in the rotation portion 50. Then, by using the stationary block gauge 52 in the rotational portion 50 as a reference, a sin value of a desired angle is derived and then a measurement block gauge (not shown) is adhered to the sin value, and the stationary block gauge 52'is adhered to the measurement block gauge, such that a under blade of the tool and the first and second angles of the peripheral cutting blade are correctly ground.

(For reference, the measurement block gauge has a width of 1.005mm - 50mm and a height dependent on the width, and has a square shape.) With the above-described method, it is possible to correctly find an original position vertex even though the stationary block gauge 52 on the rotational portion 50 moves as required, and to set +,-sin value of the tool P.

[A fourth embodiment] (A bite tip grinding method) A chuck holder 90 and a side plate 84 on the workable E 80 is released and a bite 120 is disposed at the position. In order to grind a bite tip, the bite 120 is first disposed on the workable E 80. After it is bited into a bite inserting hole 123d (127), a center point of a first elief angle of the bite is set.

That is, a bolt 125 at the back of the side plate 121 is released so that a bite holding piece 123 and a block 124 are slid upward and downward, and then a height bolt 126 at the upper side plate 121 is adjusted, such that the boss 123a of the bite holding piece 123 is guided upward and downward along

the track type hole 122 to set a center point of the bite 127.

Subsequently, the second relief angle (rotation angle) of the bite is set.

The rotational angle of the bite holding piece 123 is set on a reference of a zero point of the rotation angle scale 123c.

After the workable E 80 is vertically crossed with the bite 127 by setting the center point and the rotational angle of the bite holding piece 123 as above and then by moving the workable E 80 to the grinding whetstone 21 of the grinding portion 20 as previously stated, a grinding is performed.

INDUSTRIAL APPLICABILITY As described above, according to the present invention, a hinge is formed at the center of a body of a chuck holder and a slope scale plate is attached to a top of the hinge. Accordingly, it is possible to accurately grind an angle of a under blade of the tool such as an end mill, and to perform the first and second angles of the peripheral cutting blade of the tool using an angle adjustment lever in an end of the chuck holder. Furthermore, in the angle scale plate at a rotation portion, a measurement block gauge is adhered to a sin value of a desired angle on a basis of a fixed block gauge, thereby accurately grinding the under blade of the tool and the first and second angles of the peripheral cutting blade. Moreover, a grinding body is divided into upper and lower portions so that the upper body rotates in a desired angle, and at the same time, an angle scale plate is formed so that a worker checks up the angle in a rotation state. Furthermore, it is possible to form a spherical angle of the tool. The present invention has an advantage that it can be applied to a small cylinder grind, step, taper, division, bite, drill, and cutter.