RECTANGULAR CROSS SECTION HOT FORMING TOOL WITH MOTION MECHANISM TECHNICAL FIELD

This invention is related with the forming process and production method of the rectangular cross sectional area of the arms of the fabricated axle housings, which are used in heavy-duty commercial vehicles to carry the loads transfered from the chassis and the forces transfered through the wheel end.

The specified invention is related with the forming process and production method of the fabricated axle housing halves and obtaining the desired geometry on the bending radius of the rectangular cross section of housing arms with the use of motion of the mechanism to the sides as the punch starts to close down on the die during the forming process, thus making the forming process a two-step process which is currently a four-step process.

BACKGROUND OF THE INVENTION Currently, fabricated axle housings are one of the crucial elements which take part in heavy duty commercial vehicles. Therefore, all innovations and improvements on this element are of great importance when production costs and the increase in useful load are taken into account. The most important criterion for the axle housings which are used in modern heavy duty commercial vehicles is weight. Production of axle housings with a single sheet thickness value creates an unnecessary weight increase for the axle housing. The increase in the weight of axle housing not only decreases the useful load but also creates unnecessary production costs.

The current application of hot forming process of axle housing halves on the press consists of four steps which includes two initial forming steps and two truncated radius forming steps. These four steps can be described as; first step being initial forming, second step being ironing and weld groove forming, third step being ring side rectangular cross section truncated radius forming and fourth step being cover side rectangular cross section truncated radius forming. The aim of the 3. and 4. steps are to increase the durability of spring seat contact surfaces and to strengthen the rectangular cross section. Since the current applications has many forming steps, the operation time is longer and force required is higher due to the decrease in the workpiece temperature during the operation.

AIM OF THE INVENTION

The aim of the invention is to reduce the current number of steps for forming operation of the axle housing halves from four to two steps.

The aim of the invention is to do savings on time with the reduction on number of steps and consequently to increase efficiency. Another aim of the invention is to decrease the force required for pressing and to increase the press machine life.

The aim of the invention is to decrease the production costs close to 50 % with the reduction on number of steps for the process.

Another aim of the invention is to have balanced, well distributed and less pressing force for the operation. Since there are less number of steps for the operation and the workpiece is at a higher temperature, less pressing force will be enough for forming operation.

Another aim of the invention is to decrease hot forming tooling costs. Unlike the previous applications, the operation is performed with only one hot forming tool.

Another aim of the invention is to decrease maintenance costs and time required to mount the hot forming tool to the press, since there is not a second tool which is used for truncated radius forming.

Another aim of the invention is to obtain longer service life and more durable axle housing halves which can undertake the same task despite the fact that the number of steps for forming operation is decreased.

FIGURES RELATED WITH THE INVENTION FIGURE -1; Top view of the die for fabricated axle housing.

FIGURE -2; Top view of the punch for fabricated axle housing.

FIGURE -3; Drawing of the plate for fixing the punch mechanism in the truncated radius forming group.

FIGURE -4; Drawing of the rectangular cross section die in the truncated radius forming group.

FIGURE -5; Drawing of the lifter spring in the truncated radius forming group.

FIGURE -6; Drawing of the adjuster bolt in the truncated radius forming group.

FIGURE -7; Drawing of the punch jaw in the truncated radius forming group.

FIGURE -8; Drawing of the dove tail on the motion transfer block in the truncated radius forming group.

REFERENCE NUMBERS

100. Fabricated Axle Housing Half - Radius not Formed

105. Fabricated Axle Housing Half - Radius Formed

110. Plate

111. Plate Mounting Surface

120. Die

130. Lifting Spring

140. Spring Adjuster Bolt

150. Punch

151. Punch Guide Slot

152. Punch Jaw 153. Weld Groove Forming Region

160. Motion Transfer Block

161. Motion Transfer Wedge Dove Tail

DETAILED DESCRIPTION OF THE INVENTION

This invention is a new system for the forming process of the rectangular cross sectional area of the arms of fabricated axle housing halves, which are used in heavy-duty commercial vehicles to carry the loads transfered from the chassis and the forces transfered through the wheel end. The system consists of; plate (110) which supports the mechanism on the punch (150) that is mounted on the hydraulic press, die (120) which the unformed fabricated axle housing half (100) is placed in and which forms the unformed fabricated axle housing half (100), punch (150) which fits in the die (120) that is used to form the unformed fabricated axle housing half (100), an angular motion transfer block (160) which is used to position the punch (150) inside the die (120) and to apply pressure to the to the sides of the die (120), lifting springs (130) located on the punch (150) which are used to apply lifting force on the punch (150) after the forming process, spring adjuster bolts (140) passing through the plate (110) and located on the motion transfer block (160) and punch (150) which are used to adjust the pushing distance of the lifting springs (130).

The system also consists of, punch guide slot (151) located on the punch (150) which is used to position the motion transfer block (160) and guide its motion, motion transfer wedge dove tail (161) positioned on the die (120) which is used to apply angular force to the punch (150) on the horizontal axis and which positions the punch (150) laterally on the die (120), punch jaw (152) located on the punch (150) and angled outwards which is used to apply horizontal force on the bottom of die (120), weld groove forming region (153) located on the punch (150) which is used to form the weld groove on the upper side of the fabricated axle housing half (100) that eases the welding operation.

Die (120) and punch (150) are shown on the Figure-1 and Figure-2. During the production die (120) whose cross section is shown on the Figure-4 is positioned on the ground, and unformed fabricated axle housing half (100) is placed inside the die (120). After positioning the unformed fabricated axle housing half (100) inside the die (120), punch (150) whose cross section is shown on Figure-7 is placed. Lifting springs (130) which are shown on Figure-5 are placed on the punch (150), and motion transfer block (160) which is shown on the Figure-8 and Figure-9 is placed on the lifting springs (130). The plate (110) which is shown on the Figure-3 is placed on the motion transfer block (160) and, spring adjuster bolt (140) which is shown on the Figure-6 is connected to the motion transfer block (160) and punch (150) passing through the plate (110). Spring adjuster bolt (140) is also used for adjusting the pushing action of the lifting spring (130). After the parts are connected to each other, pressing force is applied on the plate (110) and, the motion of the punch (150) and punch guide slot (151) to the sides are provided with the use of the anglular surface of motion transfer block (160). On Figure-10 and Figure-11, different views are shown as one side is pressed and one side is not pressed. After the progression of the punch (150) to the empty areas around the outside mould line on the die (120) is completed and positioned correctly, the press is lifted upwards and the motion of the punch (150) is carried out. After the upwards motion of the punch (150), forming operation is completed with the pushing force applied by the lifting springs (130) on the formed fabricated axle housing half (105).