JP6798949B2 - Forging die equipment and forging method - Google Patents

Description

The present invention relates to a forging die device and a forging method, and more particularly to a forging die device and a forging method for manufacturing an inner joint member of a constant velocity universal joint having a track groove inclined with respect to the joint axis.

As an apparatus for manufacturing (molding) the inner joint member 1 of the constant velocity universal joint as shown in FIG. 24, the forging die apparatus described in Patent Document 1 and the like is known. The inner joint member 1 is made of a disk-shaped body having an axial center hole 2, and track grooves 3 having a curved groove bottom cross-sectional shape are formed at a predetermined pitch along the circumferential direction on the outer diameter surface thereof. As shown in FIGS. 25 and 26, this device vertically compresses a die row 6 in which a plurality of divided dies 5 are arranged in the circumferential direction and a material W1 inserted inside the die row 6 in the axial direction. It is provided with a pair of punches 7, 8 and the like. The die row 6 is arranged in a lower die (not shown) to which the lower punch 8 is attached, and the upper punch 7 is attached to the upper die (not shown).

The split die 5 is composed of a triangular block body in a plan view in which a pair of side surfaces 5a and 5a are tapered surfaces approaching from the outer diameter side of the device toward the inner diameter side of the device, and as shown in FIGS. 25 and 26, The dice row 6 is formed by arranging the eight pieces along the circumferential direction. A track groove forming mold surface 5b and an outer diameter surface forming mold surface 5c are provided on the inner diameter portion of each split die, and are always urged in the outer diameter direction by an elastic mechanism.

Therefore, in the free state, as shown in FIGS. 25 and 26, each of the divided dies 5 is in a state of being slid in the outer diameter direction, and a gap is provided between the divided dies 5 adjacent to each other in the circumferential direction. It has become. Therefore, a space larger than the material (work) W1 to be charged is formed on the inner diameter side of the die row 6.

In the forging die apparatus set in this way, the die row 6 is set to the open state as shown in FIGS. 25 and 26 in which each of the divided dies 5 is slid in the outer diameter direction, and the inner diameter side of the die row 6 is set. The material W1 is put into the space provided in. In this case, the lower punch 8 is raised, and the material W1 is received by the lower punch 8.

In this state, lower the upper mold. By this lowering, the split die 5 of the die row 6 moves in the inner diameter direction. After that, the upper punch 7 is lowered and the lower punch 8 is raised, and the upper punch 7 presses the upper surface of the material W1 and the lower punch 8 presses the lower surface of the material W1. That is, the material W1 is compressed from above and below by the upper punch 7 and the lower punch 8. As a result, the material is plastically deformed in the space surrounded by the upper and lower punches 7 and 8, and the forging is completed. That is, a forged material (not shown) is formed. After that, the forged material is taken out with the forged die device in the open state (the upper and lower dies are separated) and the lower punch 8 as a knockout pin.

JP-A-2002-130325

By the way, the groove bottom vertical cross-sectional shape has an undercut shape (the groove bottom vertical cross-sectional shape has a straight portion and a curved portion), and the track groove is inclined with respect to the inner ring axis direction. When molding the inner joint member of a constant velocity universal joint having an angle, the molding is performed by the above-mentioned conventional technique, but the ratio of materials (total height / diameter) becomes as small as 1.1 due to the characteristics of the product shape.

Further, the diameter of the split die 5 is expanded by an elastic mechanism (spring member) except during molding in order to provide a sufficient gap so that the forged material having an undercut shape does not interfere with the discharge direction. When the material W1 is put into the material W1, there is a high possibility that the gap between the split die and the material W1 becomes large and unstable. As a result, as shown in FIGS. 25 (a) and 25 (b), insertion failure (in this case, the axis WL of the material W1 is inclined with respect to the axis L of the upper and lower punches 7 and 8) may occur, or FIG. 26 (a) As shown in (b), sideways tilting (a state in which the axis WL of the material W1 is orthogonal to the axis L of the vertical punches 7 and 8) and the like occur. If such insertion failure or sideways fall occurs, molding becomes impossible (mold damage).

Therefore, in view of the above problems, the present invention provides a forging die apparatus and a forging method capable of performing high-precision forging molding without the material (work) being inserted poorly or falling sideways at the time of material injection. Is to provide.

The forging mold device of the present invention is a forging mold device for manufacturing an inner joint member of a constant velocity universal joint having a track groove inclined with respect to the joint axis, and a plurality of split dies are formed along the circumferential direction. A row of dies arranged in a row, a reciprocating mechanism that reciprocates each die of the row of dies along the radial direction, and a pair of upper and lower punches that compress the material put inside the row of dies in the axial direction. In the open state, the reciprocating mechanism is controlled to move each die in the die row in the outer diameter direction to provide a gap between adjacent dies along the circumferential direction, and each die in the die row is moved in the inner diameter direction. A control mechanism is provided at a desired timing to switch between a closed state in which adjacent dies are moved and brought into close contact with adjacent dies along the circumferential direction, and the control mechanism causes each die in the die row to be placed in the inner diameter direction at least when the material is charged. The inner joint member is formed in a closed state in which the material is moved to maintain a stable posture, and the inclined directions of adjacent track grooves in the circumferential direction are formed in opposite directions, and the groove bottom longitudinal cross-sectional shape of each track groove is formed. Is an undercut shape having an arc portion and a straight portion .

According to the forging die apparatus of the present invention, when the material is charged, each die in the die row is moved in the inner diameter direction to maintain the material in a stable posture. Therefore, the material charged into the device is in a closed state. It is possible to effectively prevent the occurrence of improper insertion and sideways fall.

The reciprocating mechanism can be configured by a cylinder mechanism, and the operation of the cylinder mechanism can be controlled by the control mechanism. The cylinder mechanism may be a pneumatic cylinder or a hydraulic cylinder. The pneumatic cylinder has a simple structure, so it is easy to handle, the price can be reduced, and the responsiveness, size / weight, and information processing capacity are average and well-balanced. A hydraulic cylinder is a cylinder that can be widely used from ultra-low speed to high speed because it can generate a large force even with a small hydraulic pump, has a very fast response speed, and is easy to control. Positioning can also be controlled accurately, and high output is possible. It may be an electric cylinder or the like. The electric cylinder is an electrically driven cylinder consisting of a ball screw, linear guide, and AC servo motor. It can be used in the same way as an air cylinder, it does not require a pump and can be used with simple wiring just by connecting it to a power supply, and it can also be used with oil mist. There are advantages such as no scattering and low running cost.

The forging method of the present invention is a forging method for manufacturing an inner joint member of a constant velocity universal joint having a track groove inclined with respect to the joint axis, and comprises a plurality of split dies arranged along the circumferential direction. A forging mold device equipped with a die row, a reciprocating mechanism that reciprocates each die of the die row along the radial direction, and a pair of upper and lower punches that axially compress the material put into the inside of the die row. A material loading process in which the material is charged inside the die row, a closing process in which the upper and lower punches are relatively close to each other, a forging process in which the upper and lower punches are further brought closer to compress the material, and an upper and lower punches are performed. It includes an opening process that relatively separates the products and a discharge process that discharges the molded product, and in the material loading process, closing process, and molding process, each die in the die row is moved in the inner diameter direction to form the material. In the opening process and the discharging process, each die in the die row is moved in the outer diameter direction to be in an open state, and the inner joint members are adjacent to each other in the circumferential direction. The inclined directions of the track grooves are formed in opposite directions, and the groove bottom vertical cross-sectional shape of each track groove is an undercut shape having an arc portion and a straight portion .

According to the forging method of the present invention, in the material charging step, the closing step, and the molding step, each die in the die row is moved in the inner diameter direction to keep the material in a stable posture. It is possible to effectively prevent the occurrence of improper insertion of the material and sideways fall. Further, in the opening step and the discharging step, each die in the die row is moved in the outer diameter direction to be in an open state, so that the forged finished product can be easily taken out from the forging die device.

In the present invention, it is possible to effectively prevent improper insertion of the input material, sideways overturning, and the like. Therefore, high-precision forging (molding) can be performed. Further, in the opening process and the discharging process, each die in the die row can be moved in the outer diameter direction to be in an open state, and the forged finished product can be easily taken out from the forging die device, resulting in productivity. Excellent for.

It is an enlarged sectional view of the main part before the closing process of the forging die apparatus of this invention. It is an enlarged sectional view of the main part which shows the discharge process of the forging die apparatus of this invention. It is a simplified diagram of a reciprocating mechanism. It is a simplified block diagram of the control circuit of the forging die apparatus of this invention. It is a block diagram of the work process of the forging method using the forging die apparatus shown in FIG. It is an enlarged cross-sectional view of a main part of a forging die apparatus before material input. It is an enlarged sectional view of the main part of the forging die device at the time of material input. It is an enlarged sectional view of the main part of the forging die apparatus at the time of contact of the upper and lower dies. It is an enlarged sectional view of the main part of the forging die apparatus when the upper and lower dies are closed. It is an enlarged sectional view of the main part of the forging die apparatus at the time of molding. It is an enlarged sectional view of the main part of the forging die device when the upper and lower dies are opened. It is an enlarged sectional view of the main part of the forging die device when the upper die is raised. It is an enlarged sectional view of the main part of the forging die apparatus at the time of discharging a forged finished product. It is a top view of the die row before material input. It is a top view of the die row at the time of material input. It is a top view of the die row in a state where the upper and lower molds are in contact with the material. It is a top view of the die row at the time of closing of the upper and lower type. It is a top view of the die row at the time of molding. It is a top view of the die row when the vertical type is opened. It is a top view of the die row when the upper die rises. It is a top view of the die row at the time of discharging a forged finished product. It is a vertical cross-sectional view of a constant velocity universal joint using an inner joint member formed by forging with the forging die device according to the present invention. It is a front view of the constant velocity universal joint shown in FIG. It is a perspective view which partially omitted the inner joint member of a constant velocity universal joint. A row of dies at the time of charging the material into the conventional forging die apparatus is shown, (a) is a plan view of a defective insertion state, and (b) is a cross-sectional view of a defective insertion state. A row of dies when the material is put into the conventional forging die apparatus is shown, (a) is a plan view of a sideways state, and (b) is a cross-sectional view of a sideways state.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 23. 1 and 2 show a cross-sectional view of a main part of the forging die apparatus according to the present invention. This forging die device forges the inner joint member 143 of the constant velocity universal joint 141 shown in FIGS. 22 and 23.

The constant velocity universal joint 141 includes an outer joint member 142 in which a plurality of track grooves 147 extending in the axial direction are formed on the spherical inner peripheral surface 146, and a plurality of pairs of the track groove 147 of the outer joint member 142 on the spherical outer peripheral surface 148. A plurality of balls as a torque transmission member that transmits torque by interposing between the inner joint member 143 in which the track groove 149 is formed, the track groove 147 of the outer joint member 142, and the track groove 149 of the inner joint member 143. It includes 144 and a cage 145 that holds the ball 144. The cage has a spherical outer peripheral surface 152 and a spherical inner peripheral surface 153 that are fitted to the spherical inner peripheral surface 146 of the outer joint member 142 and the spherical outer peripheral surface 148 of the inner joint member 143, respectively.

In this constant velocity universal joint 141, the track groove 147 of the outer joint member 142 is defined by a plane (joint center plane) orthogonal to the joint axis nn including the joint center O in a state where the operating angle is 0 °. The back side and the opening side are an arc portion 147a and a straight portion 147b with the joint center O as the center of curvature, respectively. On the other hand, the track groove 149 of the inner joint member 143 has an arc portion 149a and a straight portion 149b having the joint center O as the center of curvature, respectively, on the opening side and the back side of the joint center plane as a boundary.

Then, as shown in FIG. 23, the track grooves 147 and 149 are inclined in the circumferential direction with respect to the axis of the joint, and the inclined directions are adjacent to each other in the circumferential direction at the track grooves 147A, 147B and 149A, 149B, respectively. It is formed in the opposite direction. Therefore, the arc portion 147a of the track groove 147A is called the arc portion 147Aa, the straight portion 147b of the track groove 147A is called the arc portion 147Ab, the arc portion 147a of the track groove 147B is called the arc portion 147Ba, and the straight portion of the track groove 147B is straight. The portion 147b will be referred to as an arc portion 147Bb. Further, the arc portion 149a of the track groove 149A is called an arc portion 149Aa, the straight portion 149b of the track groove 149A is called an arc portion 149Ab, the arc portion 149a of the track groove 149B is called an arc portion 149Ba, and the straight portion of the track groove 149B. 149b will be referred to as an arc portion 149Bb.

Balls 144 are arranged at the intersections of the track grooves 147A, 149A, 147B, and 149B that form a pair of the outer joint member 142 and the inner joint member 143. Therefore, when both joint members 142 and 143 rotate relative to each other when the operating angle is 0 ° as shown in the drawing, they are formed between the opening direction of the wedge angle formed between the track grooves 147A and 149A and between 147B and 149B. Since the opening directions of the wedge angles are opposite to each other and the forces in the opposite directions from the ball 144 act on the pocket portions 145a adjacent to each other in the circumferential direction of the cage 145, the cage 145 is stable at the joint center O position. To do. Therefore, the contact force between the spherical outer peripheral surface 152 of the cage 145 and the spherical inner peripheral surface 146 of the outer joint member 142, and the contact between the spherical inner peripheral surface 153 of the cage 145 and the spherical inner peripheral surface 148 of the inner joint member 143. As a result of the force being suppressed and the operability of the joint being improved, torque loss and heat generation are suppressed, and durability is improved.

In the forging die apparatus of the present invention, the columnar material (work) W1 made of carbon steel or the like shown in FIG. 1 or the like is shown in the finished shape of the track groove 149 and the shape having a spherical outer surface, that is, FIG. 24. The inner joint forged product 143'of the shape will be forged. Then, as shown in FIG. 10 and the like, the forged material W obtained by this forging is a non-penetrating material in which the inner diameter hole 19 has a bottom wall 20 in the middle in the axial direction. Therefore, the bottom of the forged material W is punched or removed by a turning process, a female spline is formed in the inner diameter hole thereof, and the width surface and the outer surface of the spherical surface are finished by machining such as turning or grinding. Further, the inner joint member 143 of the constant velocity universal joint is formed by machining the details such as the opening edge of the inner diameter hole and performing heat treatment. The inner joint forged product 143'is a part that has not been finished by machining or heat treatment, and has the same shape as the inner joint member 1 of the conventional constant velocity universal joint. For this reason, FIG. 24 showing the conventional inner joint member 1 is designated by reference numeral 143'of the inner joint forged product forged by the forging die device of the present invention.

As shown in FIG. 6, the forging die apparatus includes an upper die 21, a lower die 22, an upper punch member 23 arranged on the upper die 21 side, and a lower punch member arranged on the lower die 22 side. 24 and a die row 26 and the like arranged on the lower die 22 side are provided.

The upper die 21 can be raised and lowered by an upper die raising and lowering drive mechanism K1 (see FIG. 4) such as a hydraulic cylinder. Further, the upper die 21 is formed with a hole 27 in which the upper punch member 23 can be moved up and down, and the upper punch member 23 is moved up and down by an upper punch vertical movement mechanism U1 (see FIG. 4) such as a hydraulic cylinder. It is made movable. As shown in FIGS. 6 to 13, the upper punch member 23 has a punch main body 23a, an upper ring punch 23b arranged on the outer peripheral side of the punch main body 23a, and a boss portion 23c that receives them. A guide structure 28 for guiding the upper punch member 23 is provided on the inner diameter surface of the hole 27.

The lower mold 22 can be raised and lowered by a lower mold raising and lowering drive mechanism K2 (see FIG. 4) such as a hydraulic cylinder. Further, the lower die 22 is formed with a hole 30 in which the lower punch member 24 can be moved up and down, and the lower punch member 24 is moved up and down by a lower punch vertical movement mechanism U2 (see FIG. 4) such as a hydraulic cylinder. It is made movable. As shown in FIGS. 1 and 2, the lower punch member 24 has a punch body 24a, a ring punch 24b arranged on the outer peripheral side of the punch body 24a, and a boss portion 24c that receives them. A guide structure 31 for guiding the lower punch member 24 is provided on the inner diameter surface of the hole 30.

As shown in FIGS. 14 and 15, the die row 26 arranged on the lower mold 22 side is composed of a plurality of (8 in the example) divided dies 25 arranged along the circumferential direction. .. Each split die 25 is composed of a triangular block body in a plan view in which a pair of side surfaces 25a and 25a are tapered surfaces that approach from the outer diameter side of the device toward the inner diameter side of the device.

The side surfaces 25a and 25a extend in the radial direction, and as shown in FIGS. 14 and 15, the side surfaces 25a and 25a slide toward the center of the device so that the side surfaces of the split dies 25 adjacent to each other in the circumferential direction come into contact with or come into close contact with each other. In this state, the dice row 26 has a plan view ring shape. Further, a track groove forming mold surface 25b and an outer diameter surface forming mold surface 25c are provided at a predetermined pitch on the inner diameter portion of each of the divided dies of the die row 26. The outer diameter portion of each split die 25 is a tapered surface portion 29 whose diameter increases in the outer diameter direction from the upper side to the lower side. The tapered surface portion 29 includes a central first portion 29a, a pair of second portions 29b and 29b on both sides of the first portion 29a, and a pair of side portions 29c and 29c connected to the second portions 29b and 29b. It consists of.

As shown in FIGS. 1 and 2, each of the split dies 25 reciprocates along the radial direction via the reciprocating mechanism M. The reciprocating mechanism M is composed of a cylinder mechanism M1. The cylinder mechanism M1 in this case is a single-acting cylinder including a cylinder tube 32, a piston rod 33 fitted in the cylinder tube 32, and a spring 34 housed in the cylinder tube 32.

The cylinder tube 32 is provided with a first chamber 35 and a second chamber 36. That is, the cylinder tube 32 includes a main body portion 32a made of a bottomed cylindrical body and a lid member 32b provided at the opening of the main body portion 32a, and a recess of the bottom wall 32a1 of the main body portion 32a is provided. The second chamber 36 is configured. Further, the first chamber 35 is formed between the lid member 32b and the bottom wall 32a1 of the main body 32a.

The piston rod 33 is composed of a piston portion 33a and a shaft body 33b, and the piston portion 33a is reciprocally fitted into the first chamber 35, and the shaft body 33b is inserted from the first chamber 35 through the through hole of the lid member 32b. Protrude to the outside. A spring 34 is interposed between the piston portion 33a and the lid member 32b. Therefore, in the free state, as shown in FIG. 1, the piston rod 33 is pressed by the elastic force of the spring 34, and the piston portion 33a is in contact with the bottom wall 32a1 of the main body portion 32a.

A connecting member 37 connected to the split die 25 is attached to the protruding end of the shaft body 33b of the piston rod 33. The connecting member 37 has a first portion 37a that is attached to the protruding end of the shaft body 33b of the piston rod 33 via a bolt member 40 and extends in the axial direction, and a second portion that extends in the inner diameter direction from the first portion 37a. It is composed of 37b and a third portion 37c extending in the axial direction (vertical direction) from the second portion 37b, and the third portion 37c is connected to the split die 25 via a bolt member 41. The split die 25 is provided on the lower die 22 and is received by the cradle 42.

Then, a hydraulic path 39 is connected to the second chamber 36, and oil is supplied from the hydraulic path 39 to the second chamber 36. Therefore, in the state shown in FIG. 1 (a state in which hydraulic pressure is not supplied to the second chamber 36 and the piston portion 33a is in contact with the bottom wall 32a1 of the main body portion 32a), the split die 25 has an inner diameter. As shown in FIGS. 14 and 15, the dice rows 26 in a state where the side surfaces 25a and 25a of the divided dies 25 adjacent to each other in the circumferential direction are in contact with each other in the direction are closed.

If the flood control is supplied to the second chamber 36 from the state shown in FIG. 1, the piston rod 33 moves in the outer diameter direction as shown in FIG. When the split dies 25 are moved in this way, the split dies 25 connected via the connecting member 37 move in the outer diameter direction, and the die rows 26 are in an open state (the side surfaces of the split dies 25 adjacent to each other along the circumferential direction. A state in which a gap is formed between 25a and 25a, a state shown in FIGS. 19 to 21 and the like).

By the way, the cylinder mechanism M1 is connected to each of a plurality of (in this case, eight) split dies 25 along the circumferential direction as shown in FIG. A hydraulic path 39 is connected to each cylinder mechanism M1. A hydraulic tank 45, a pressure reducing control valve 46, a control valve 47, shuttle valves 48, 49 and the like are arranged in the hydraulic passage 39, and a hydraulic circuit H is formed.

Further, as shown in FIG. 6 and the like, the upper die 21 is provided with a die base 50, and an upper plate 51 is provided inside the die base 50. The die base 50 has a plurality of recesses 52 into which the outer diameter ends of the split dies 25 are fitted, and a die guide is provided on the inner surface of the recesses 52 so as to be along the outer diameter portion of the split dies 25. A surface 53 is formed. That is, the die guide surface 53 becomes a surface that presses the split die 25 in the inner diameter direction by moving the die base 50 in the axial direction.

This device includes a control mechanism (control means) 55 as shown in FIG. It can be composed of a microcomputer or the like in which a ROM (Read Only Memory), a RAM (Random Access Memory), or the like is connected to each other via a bus, centering on a CPU (Central Processing Unit). Further, the control mechanism 55 is provided with a storage device as a storage means, and the timing of the vertical movement of the vertical type 21 and 22, the timing of the vertical movement of the vertical punch members 23 and 24, and the timing of switching to the control valve 47 of the hydraulic circuit H. Etc. are stored in advance. A storage device as a storage means includes an HDD (Hard Disc Drive), a DVD (Digital Versatile Disk) drive, a CD-R (Compact Disc-Recordable) drive, an EEPROM (Electronically Erasable and Programmable Read Only Memory), and the like. The ROM stores programs and data executed by the CPU. That is, the timing control of the up / down operation of the vertical type 21 and 22, the vertical operation of the vertical punch, and the opening / closing operation of the dice row is performed.

As shown in FIG. 5, the forging method of the present invention includes a material charging step 61, a closing step 62, a molding step 63, an opening step 64, and a discharging step 65, using the forging die apparatus. .. In the material charging step 61, a preparatory step (before material charging (closed)) in which the die row before the material is charged into the forging die device is closed, and a material is transferred to the forging die device with the die row 26 closed. There is a charging process (when the material is charged (closed)). Further, in the closing step 62, a step of bringing the upper and lower dies 21 and 22 into contact with the material while keeping the die row 26 closed (when the upper and lower dies are in contact (closed)) and the upper and lower dies are relatively close to each other. There is a step of putting the mold device in a closed state (when the upper and lower molds are closed (closed)). The molding step 63 is a step (during molding (closed)) in which the upper and lower punch member members 23 and 24 are brought close to each other for molding. In the opening step 64, the upper and lower dies 21 and 22 are separated from each other to open the die row (when the upper and lower dies are opened (open)), and the upper die 21 is raised while the upper and lower dies 26 are left open. There is a process (when the upper mold rises (open)). The discharge step 65 is a step (when the work is discharged (open)) in which the forged material is discharged from the mold apparatus. In addition, (closed) in each step of FIG. 5 means that the die row 26 is in the closed state (the piston rod 33 is moved in the inner diameter direction by the elastic force of the spring 34 without supplying the oil pressure to the second chamber 36 of the cylinder mechanism M1. Indicates that the split dies 25 are being moved in the inner diameter direction), and the (open) in each step of FIG. 5 means that the die row 26 is in the open state (the second cylinder mechanism M1). It is shown that the state is such that the flood control is supplied to the chamber 36, the piston rod 33 is moved in the outer diameter direction against the elastic force of the spring 34, and each split die 25 is moved in the outer diameter direction). ing.

Next, the steps shown in FIG. 5 will be described with reference to FIGS. 6 to 13 and 14 to 21. First, as shown in FIG. 6, the upper mold 21 and the lower mold 22 are separated from each other in the mold device open state. At this time, the lower punch member 24 is lowered. Further, the piston rod 33 is moved in the inner diameter direction by the elastic force of the spring 34 without supplying the second chamber 36 of the cylinder mechanism M1, and each split die 25 is moved in the inner diameter direction to move the split die 25. 25 is moved in the inner diameter direction. That is, as shown in FIG. 14, the dice row is closed so that the side surfaces of the divided dies 25 adjacent to each other in the circumferential direction are in contact with each other. This is the preparatory process (before material input (closed)).

In this state, as shown in FIG. 7, a charging step (when the material is charged (closed)) is performed in which the cylindrical material (work) W1 is charged inside the die row 26. When the material W1 is charged in this way, the lower surface W1a of the material W1 is received by the upper surface 24a1 of the punch body 24a of the lower punch member 24, and the outer peripheral surface W1c of the material W1 is a die as shown in FIG. They are in contact with each other at the inner diameter surface of the row 26. As a result, the material W1 is held at a regular position whose axis coincides with the axes of the upper and lower punch members 23 and 24.

Next, as shown in FIG. 8, the upper die 21 and the lower die 22 are relatively close to each other, and the lower surface 23a1 of the punch body 23a of the upper punch member 23 is brought into contact with the upper surface W1b of the material W1. That is, it is in the vertical contact (closed) state of the closing step 62 shown in FIG. After that, as shown in FIG. 9, the upper punch member 23 and the lower punch member 24 are brought closer to each other. As a result, a step of fitting the lower portion of the upper punch member 23 into the recess formed in the upper surface W1b of the material W1 and fitting the upper portion of the lower punch member 24 into the recess formed in the lower surface W1a of the material W1, that is, , When the upper and lower molds are closed (closed) as shown in FIG. In the state shown in FIGS. 8 and 9, as shown in FIGS. 16 and 17, the outer peripheral surface W1c of the material W1 is in contact with the inner diameter surface portion of the die row 26.

Next, as shown in FIG. 10, the upper punch member 23 and the lower punch member 24 are further brought closer to each other, and the forged material W (the inner diameter hole 19 is a non-penetrating material having a bottom wall 20 in the middle in the axial direction). Is formed as shown in FIG. That is, the molding (closed) of FIG. 5 is performed. In this case, in the upper punch member 23, the lower surface 23b1 of the upper ring punch 23b is retracted upward from the lower end portion of the punch body 23a, and the lower surface 23b1 is recessed below the upper end portion of the lower punch member 24 below the lower ring punch 24b. It is retreating.

Therefore, an inner diameter hole 19 with a bottom wall 20 is formed at the lower end of the punch body 23a of the upper punch member 23 and the upper end of the punch body 24a of the lower punch member 24, and the upper ring punch 23b of the upper punch member 23 is formed. The lower surface 23b1 (see FIG. 6) forms the upper surface Wb of the forged material (forged work) W, and the upper surface 24b1 (see FIG. 1) of the lower ring punch 24b of the lower punch member 24 is the lower surface of the forged work W. Form Wa. After that, as shown in FIG. 11, the upper and lower molds 21 and 22 are separated from each other, and the split die 25 of the die row 26 is slightly slid in the outer diameter direction to open the die row 26 as shown in FIG. State (Flood control is supplied to the second chamber 36 of the cylinder mechanism M1, the piston rod 33 is moved in the outer diameter direction against the elastic force of the spring 34, and each split die 25 is moved in the outer diameter direction. In the state of being). That is, when the upper and lower molds shown in FIG. 5 are open (open). In the open state shown in FIG. 19, the split die 25 can be further slid in the outer diameter direction.

After that, as shown in FIG. 12, the upper and lower molds 21 and 22 are separated to raise the upper punch member 23, and as shown in FIG. 20, the split die 25 is further slid in the outer diameter direction to form the die row 26. (The flood control is supplied to the second chamber 36 of the cylinder mechanism M1 to move the piston rod 33 in the outer diameter direction against the elastic force of the spring 34, and each split die 25 is moved in the outer diameter direction. The state of being made). That is, it is assumed that the upper mold is raised (open) in FIG. Next, as shown in FIG. 13, the lower punch member 24 is raised to take out the forged work W (in this state, the die row 26 is in the state shown in FIG. 21). That is, it is assumed that the work is discharged (open) in FIG. As a result, the forging process is completed.

According to the forging die apparatus of the present invention, when the material is charged, each die 25 of the die row 26 is moved in the inner diameter direction to maintain the material W1 in a stable posture. It is possible to effectively prevent the occurrence of improper insertion of the material W1 and sideways fall.

It is possible to effectively prevent the inserted material W1 from being improperly inserted or falling sideways. Therefore, high-precision molding can be performed. Further, in the opening step 64 and the discharging step 64, each die 25 of the die row 26 can be opened in the outer diameter direction, and the forged work (forged material) W, which is a forged finished product, can be in an open state. It is easy to take out from the forging die equipment and has excellent productivity. Further, in the material charging step 61, the closing step 62, and the molding step 63, since each die 25 of the die row 26 is moved in the inner diameter direction to keep the material in a stable posture, the track groove 149 is the joint axis. Even if the shape is undercut, it is possible to effectively prevent the occurrence of improper insertion and sideways tilting, and stable forging (molding) can be performed.

The reciprocating mechanism M is configured by the cylinder mechanism M1, and the operation of the cylinder mechanism M1 can be controlled by the control mechanism 55. The cylinder mechanism M1 may be a pneumatic cylinder or a hydraulic cylinder. The pneumatic cylinder has a simple structure, so it is easy to handle, the price can be reduced, and the responsiveness, size / weight, and information processing capacity are average and well-balanced. A hydraulic cylinder is a cylinder that can be widely used from ultra-low speed to high speed because it can generate a large force even with a small hydraulic pump, has a very fast response speed, and is easy to control. Positioning can also be controlled accurately, and high output is possible. It may be an electric cylinder or the like. The electric cylinder is an electrically driven cylinder consisting of a ball screw, linear guide, and AC servo motor. It can be used in the same way as an air cylinder, it does not require a pump and can be used with simple wiring just by connecting it to a power supply, and it can also be used with oil mist. There are advantages such as no scattering and low running cost.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment and can be modified in various ways. As a constant velocity universal joint, an undercut-free type fixed constant velocity universal joint is used. However, it may be a barfield type fixed constant velocity universal joint, or a cross groove type sliding constant velocity universal joint. When a cross-groove type constant velocity universal joint is used, it may be a float type or a non-float type, and when a tripod type is used, it may be a single roller type or a double roller type. Further, the number of track grooves of the inner joint member can be increased or decreased arbitrarily, and the groove shape is not limited to the undercut shape, and the groove bottom may be only an arc portion. That is, the number of the divided dies 25 in the die row 26 can be increased or decreased arbitrarily, and the shapes of the track groove forming mold surface 25b and the outer diameter surface forming mold surface 25c can also be arbitrarily set.

When the upper and lower molds 21 and 22 are approached and separated, the upper mold 21 is fixed even if the lower mold 22 is fixed and only the upper mold 21 is moved up and down, or both the upper and lower molds 21 and 22 are moved up and down. You may move only the lower mold up and down. Further, when the upper and lower punch members 23 and 24 are approached and separated from each other, the lower punch member 24 may be fixed and only the upper punch member 23 may be moved up and down, or both the upper and lower punch members 23 and 24 may be moved up and down. The upper punch member 23 may be fixed and only the lower punch member 24 may be moved up and down.

Further, in the above-described embodiment, the die row 26 is closed in the material charging step 61, the closing step 62, and the molding step 63, and the die row 26 is opened in the opening step 64 and the discharging step 65. Such a configuration is preferable for high-precision forging. However, since the control mechanism (control means) 55 can switch between the open state of the die row 26 and the closed state of the die row 26 at a desired timing, at least in the material charging step 61, the die Since it is sufficient that the row 26 is in the closed state, the die row 26 can be closed or opened in another step.

23 Upper punch member 24 Lower punch member 25 Divided die 25a Side surface 26 Die row 55 Control mechanism 61 Material input process 62 Closing process 63 Molding process 64 Opening process 65 Discharging process 143 Inner joint member 149 Track groove 149a Arc part 149b Straight part M Reciprocating Dynamic mechanism M1 Cylinder mechanism W1 Material (work)
W Forged material (forged work)

Claims (3)

A forging die device for manufacturing an inner joint member of a constant velocity universal joint having a track groove inclined with respect to the joint axis.
A die row in which a plurality of split dies are arranged along the circumferential direction, a reciprocating mechanism for reciprocating each die in the die row along the radial direction, and a material charged inside the die row in the axial direction. Equipped with a pair of upper and lower punches to compress into
By controlling the reciprocating mechanism, each die in the die row is moved in the outer diameter direction to provide a gap between adjacent dies along the circumferential direction, and each die in the die row is moved in the inner diameter direction. A control mechanism is provided to switch to a closed state in which adjacent dies are brought into close contact with each other along the circumferential direction at a desired timing, and the control mechanism moves each die in the die row in the inner diameter direction at least when the material is charged. The inner joint member is formed in a closed state in which the material is maintained in a stable posture, and the inclined directions of the adjacent track grooves in the circumferential direction are formed in opposite directions, and the groove bottom longitudinal cross-sectional shape of each track groove is formed. A forging mold device having an undercut shape having an arc portion and a straight portion . The forging die device according to claim 1, wherein the reciprocating mechanism is composed of a cylinder mechanism, and the operation of the cylinder mechanism is controlled by the control mechanism. A forging method for manufacturing an inner joint member of a constant velocity universal joint having a track groove inclined with respect to the joint axis.
A row of dies in which a plurality of split dies are arranged along the circumferential direction, a reciprocating mechanism for reciprocating each die of the row of dies along the radial direction, and a material charged inside the row of dies in the axial direction. Using a forging die device equipped with a pair of upper and lower punches to compress
The material loading process in which the material is charged inside the die row, the closing process in which the upper and lower punches are relatively close to each other, the molding process in which the upper and lower punches are further brought closer to compress the material, and the upper and lower punches are relatively close to each other. It is equipped with an opening process for separating and discharging a molded product, and in the material charging process, closing process, and molding process, each die in the die row is moved in the inner diameter direction to stabilize the material. In the opening step and the discharging step, each die in the die row is moved in the outer diameter direction to be in the open state, and the inner joint member is formed of track grooves adjacent to each other in the circumferential direction. A forging method characterized in that the inclination directions are formed in opposite directions and the groove bottom vertical cross-sectional shape of each track groove is an undercut shape having an arc portion and a straight portion .

Images