KR102177398B1 - Apparatus for molding by forging - Google Patents

Abstract

(assignment)
The present invention is to provide a forging molding apparatus and a molding method capable of easily achieving both in formation of high-precision grooves with respect to the inner diameter and improvement in productivity.
(Solution)
As a forging molding apparatus, the base 20, the inner punch 30, and the inner punch 30 between the collision position colliding with the workpiece 10 and a separation position separated from the workpiece 10 The inner punch 30 is provided with an inner punch driving unit 50 that repeatedly displaces the inner punch 30, and the inner punch 30 includes a forging unit 32 and a groove forming unit 34 for forging the inner circumferential surface of the workpiece, and forging The portion 32 is formed at a position opposite to the workpiece 10 and has a shape having the inner peripheral surface as a reference inner peripheral surface 10b by forging the inner peripheral surface 10a of the workpiece 10, and has a groove forming portion 34 ) Has a shape that protrudes outward from the rear end of the forged portion 32 in the conveying direction to form a groove 10c on the reference inner peripheral surface 10b.

Description

Forging molding equipment{APPARATUS FOR MOLDING BY FORGING}

The present invention relates to a forging molding apparatus.

Conventionally, for a material to be processed having a forged inner circumferential surface, a keyway or spline, etc. (hereinafter simply referred to as ``groove (groove)") processing is sometimes performed. For example, in Patent Document 1, first, by forging a disk-shaped workpiece, a ring-shaped intermediate molded product having a through hole in the center is formed, and then on the inner circumferential surface of the intermediate molded product. A molding method is disclosed in which a final molded product is molded by forming a groove by broach processing.

Patent Document 1; Japanese Unexamined Patent Application Publication No. 2013-040652

In the same molding method as described in Patent Document 1, since forging and broaching must be performed sequentially in separate facilities, the man-hours required to obtain the desired final molded product from the workpiece are required. There are many problems that it is difficult to improve productivity. Specifically, in order to implement the molding method described in Patent Document 1, in general, first, the workpiece is clamped in a clamping portion of a forging device for forging the workpiece, and the clamped workpiece is forged, so that the intermediate The molded article is molded. After that, the intermediate molded product is separated from the clamping portion of the forging device, and the intermediate molded product is clamped to the clamping portion of the broach processing device. Then, the inner circumferential surface of the intermediate molded product is cut by a brooch to form a groove. In this way, the above molding method is accompanied by a very cumbersome operation.

In addition, there is a concern that the processing precision of the grooves is also deteriorated because the formation of the intermediate molded article and the formation of the grooves in the intermediate molded article are performed by separate devices. Specifically, due to the tolerance of the intermediate molded product formed by forging the workpiece by the forging device, the intermediate molded product may be pinched in the holding portion of the broach processing apparatus in a slightly shifted posture from the normal posture. In this case, the processing precision of broach processing is remarkably lowered.

It is an object of the present invention to provide a forging molding apparatus and a molding method capable of easily achieving both in the improvement of productivity and formation of grooves with high precision for the inner diameter.

In order to solve the above problems, the present inventors conceived of forming an inner circumferential surface for a material to be processed and forming a groove on the inner circumferential surface by a single inner punch. However, if the inner circumferential surface is formed and the groove is formed simultaneously with respect to the work piece, friction generated between the inner punch and the work piece increases, and there is a concern that seizure occurs in the inner punch.

Therefore, the present invention is a forging molding apparatus, comprising: a base on which a workpiece having a through hole can be placed, an inner punch for processing an inner circumferential surface surrounding the through hole of the workpiece, and the inner punch The inner punch is repeatedly displaced between the collision position colliding with the workpiece by displacing in the direction of conveyance and the separating position separated from the workpiece by displacing the inner punch in a separating direction opposite to the conveying direction. An inner punch driving part is provided, and the inner punch includes a forging part for forging an inner circumferential surface of the workpiece, and a groove forming part formed at a rear of the forging part with respect to the conveying direction, and the forging part comprises: Formed at a position opposite to the material to be processed placed on the pedestal, and by forging the inner circumferential surface of the material to be processed, the inner circumferential surface of the cross section in the direction orthogonal to the conveying direction is formed as a uniform reference inner circumferential surface throughout the conveying direction And the groove forming part protrudes outward from the rear end of the forging part with respect to the conveying direction, thereby providing a forging molding apparatus having a shape capable of forming a groove in the reference inner circumferential surface.

According to the present invention, after the reference inner circumferential surface is formed in the material to be processed by the forging part, a groove is formed on the reference inner circumferential surface by the groove forming unit, and the inner punch repeats collision and separation against the workpiece. Since friction generated between the inner punch and the material to be processed is drastically reduced by displacement, the occurrence of sticking on both the forged portion and the groove forming portion is suppressed, and thus, a single inner punch is used to avoid It becomes possible to forge the inner circumferential surface of the processed material and to form a groove on the reference inner circumferential surface in a single process. Specifically, a reference inner circumferential surface of a cross section in a direction orthogonal to the conveying direction is formed on the workpiece by the forging part over the entire conveying direction, and a groove is formed on the reference inner circumferential surface by the groove forming part. Since it is formed, in the step of forming the groove on the reference inner circumferential surface, since the cross-sectional reduction rate of the workpiece is constant, that is, the pressure acting on the groove forming portion becomes uniform, friction generated between the inner punch and the workpiece is reduced. In addition, the inner punch is displaced while repeatedly colliding and separating the workpiece, i.e., before the resistance received by the inner punch from the excess thickness of the workpiece generated by press-fitting the workpiece in the conveying direction of the inner punch When the inner punch is separated from the material to be processed, the friction that occurs between the inner punch and the material to be processed is significantly reduced while the resistance is reduced while pressing the material to be processed in the conveying direction. Accordingly, the occurrence of sticking on both the forged portion and the groove-forming portion is suppressed, and forging the inner peripheral surface of the workpiece and forming the groove on the reference inner peripheral surface can be performed in a single step. Therefore, the broach process as in the prior art is omitted, and the man-hours for obtaining a desired molded article from the workpiece are reduced. For this reason, the conventional process, that is, the process of installing and fixing the forged intermediate molded product in a brooch processing device different from the forging device, is omitted, thereby avoiding the reduction in the processing precision of the groove due to the tolerance of the intermediate molded product. Therefore, it becomes possible to form a groove with high precision.

In this case, it is preferable that the forging portion includes a guide portion extending from the tip of the groove forming portion toward the conveying direction with respect to the conveying direction and having an outer peripheral surface parallel to the conveying direction.

In this way, in a state in which the guide portion is guided by the reference inner circumferential surface, that is, in a state in which displacement in a direction orthogonal to the transport direction in the guide portion is suppressed, Since the groove is formed on the reference inner circumferential surface by the groove forming portion, the processing precision of the groove is further improved.

In addition, in the present invention, further comprising an outer punch disposed outside the inner punch, the pedestal, while surrounding the outer circumferential surface of the processed material and forming an outer shape of the processed material And the outer punch has a shape capable of pressing the processed material in the conveying direction so that the outer surface of the processed material is in close contact with the shape forming part by expanding the material to be processed. desirable.

In this way, without separating the workpiece from the pedestal, the outer diameter is processed in addition to the inner diameter of the workpiece, and the outer punch is so that the outer surface of the workpiece is in close contact with the outer shape forming part by expanding the workpiece. Since the outer punch has a shape capable of pressing the workpiece to the outer shape forming portion in the transport direction, the outer punch presses the workpiece to the outer shape forming portion, that is, the transport direction of the workpiece to the pedestal The processing precision of the inner diameter of the workpiece is further increased by processing the workpiece by the inner punch while the displacement in the direction perpendicular to the base is constrained by the pedestal.

In addition, in the present invention, the inner punch drive unit applies a pressing force for pressing the inner punch into the workpiece as the amount of displacement of the inner punch in the conveying direction increases from the position where the inner punch first contacts the workpiece. It is preferable to provide a pressing force setting portion to increase.

In this way, smooth processing of the inner circumferential surface of the workpiece by the inner punch is possible. In general, as the amount of displacement of the inner punch in the transfer direction increases, an extra thickness of the material to be processed is generated, so that the pressing force gradually increases. For this reason, for example, when the pressing force is constant, the amount of displacement of the inner punch in the conveying direction (the processing speed of the inner circumferential surface by the inner punch) gradually decreases. On the other hand, in the present invention, since the pressing force gradually increases as the amount of displacement of the inner punch in the conveying direction increases, smooth processing of the inner circumferential surface is possible, thereby improving productivity.

In addition, in the present invention, it is preferable that the inner punch driving unit includes a speed adjusting unit capable of adjusting a speed at which the inner punch is displaced from the collision position toward the separation position.

In this way, the processed material can be processed while flexibly responding to the material or shape of the material to be processed.

As described above, according to the present invention, it is possible to provide a forging molding apparatus and a molding method capable of easily achieving both in formation of a groove with high precision with respect to an inner diameter and improvement in productivity.

1 is a diagram schematically showing a forging molding apparatus according to an embodiment of the present invention.
Fig. 2 is a diagram schematically showing the forging molding apparatus of Fig. 1;
Fig. 3 is a bottom view of an inner punch in the forging molding apparatus of Fig. 1;
4 is a diagram showing the configuration of an inner punch drive unit.
5 is a graph showing the relationship between the inner punch and the resistance acting on the inner punch.

A forging molding apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5.

As shown in Figs. 1 and 2, the forging molding apparatus of this embodiment includes a pedestal 20 capable of placing a workpiece 10, and an inner punch. (30) and an outer punch (40) are provided. Further, this forging molding apparatus is provided with an inner punch drive unit 50 for driving the inner punch 30 as shown in FIG. 4. In this forging machine, bevel gear, differential side gear, hypoid ring gear, spur gear, sleeve yoke, and other deformities ( It is possible to mold a molded product equipped with 異形形狀). In addition, in FIG. 1, a state before the inner punch 30 and the outer punch 40 are brought into contact with the workpiece 10 together is shown to the left of the central axis O of the inner punch 30, and the central axis O To the right of ), the outer punch 40 presses the workpiece 10 against the pedestal 20, and the inner punch 30 is processing the inner diameter of the workpiece 10. Is shown. In Fig. 2, on the left side of the central axis O, the outer punch 40 presses the workpiece 10 against the pedestal 20, and the inner punch 30 processes the inner diameter of the workpiece 10. A state in the middle is shown, and a state in which processing of the inner diameter of the workpiece 10 by the inner punch 30 has been completed is shown to the right of the central axis 0. In the following description, the lower side of Figs. 1 and 2 is referred to as the lower side or the front side, and the upper side of Figs. 1 and 2 is the upper side or the rear side. It is called.

The material to be processed 10 is an annular member having an inner circumferential surface 10a that surrounds a through hole. Specifically, the center of the cold, warm, or hot forged material is pierced, thereby forming the workpiece 10 having a through hole. Further, on the right side of the central axis O in Fig. 1 and on the left side of the central axis 0 in Fig. 2, the position of the inner circumferential surface 10a before machining is indicated by a chain two-dotted line.

The pedestal 20 is provided with an external shape forming portion 22 of a shape capable of mounting the material 10 to be processed and forming the external shape of the material 10 to be processed. The outer shape forming part 22 has a concave shape surrounding the periphery of the workpiece 10. The pedestal 20 of this embodiment includes an inner punch 30 and an inner circumferential surface 24 enclosing a space allowing insertion of the punching residue 14 (refer to FIG. 2) of the workpiece 10. The lower end of the outer shape forming part 22 is connected to the upper end of the inner circumferential surface 24.

As shown in Figs. 1 and 2, the inner punch 30 is a tool that processes the inner circumferential surface 10a of the workpiece while being repeatedly displaced in the vertical direction. More specifically, the inner punch 30 collides with the workpiece 10 by displacing the inner punch 30 in the conveying direction toward the workpiece 10 (downward in Figs. 1 and 2). The inner punch 30 is repeatedly displaced between the collision position and the separation position separated from the workpiece 10 by displacing in the separation direction opposite to the transfer direction (above Figs. 1 and 2). While processing the inner peripheral surface (10a) of the workpiece. This operation of the inner punch 30 is realized by the inner punch drive unit 50. This point will be described in detail later. Specifically, the inner punch 30 includes a forged portion 32 forging the inner circumferential surface 10a of the workpiece 10, and a keyway or spline in the workpiece 10. It is provided with a groove-forming part (34) forming a groove (groove).

The forging portion 32 is formed at a position facing the workpiece 10 placed on the pedestal 20. As shown in Fig. 2, the forged portion 32 forms a reference inner circumferential surface 10b on the processed material 10 by forging the inner peripheral surface 10a of the material 10 to be processed. The reference inner circumferential surface 10b is an inner circumferential surface in which the inner circumferential surface of the cross section in a direction orthogonal to the axial direction of the central axis O is uniform over the entire axial direction. As shown in Fig. 3, the forged portion 32 has a flat portion 32a parallel to a plane orthogonal to the axial direction, and extends upward with respect to the axial direction from the flat portion 32a. A guide portion 32c having an inclined portion 32b having a shape to be formed and an outer peripheral surface parallel to the axial direction (transport direction) is provided. The flat portion 32a is formed at the tip end of the inner punch 30 (lower end in Fig. 1). The inclined portion 32b has a shape in which the outer diameter of the flat portion 32a gradually increases as it faces upward from the outer edge of the flat portion 32a. The guide portion 32c extends upward from the upper end of the inclined portion 32b and is connected to the groove-forming portion 34, in other words, the transfer direction from the tip (lower in Fig. 1) of the groove-forming portion 34. It has a shape that extends along and continues to the outer edge of the inclined portion 32b. The outer diameter of the guide portion 32c is larger than that of the flat portion 32a. In this embodiment, the flat portion 32a and the inclined portion 32b have a conical trapezoid shape, and the guide portion 32c has a cylindrical shape. That is, the inner circumferential surface 10a of the workpiece 10 is processed to become the reference inner circumferential surface 10b by the guide portion 32c.

The groove-forming part 34 is formed immediately after the forging part 32 (right above the forged part 32 in FIG. 1) with respect to the conveying direction, and the reference inner circumferential surface 10b formed by the forged part 32 ) To form a groove. This groove-forming part 34 includes a base 34a and a protrusion 34b.

The base 34a has a shape extending upward from the rear end of the guide portion 32c. In this embodiment, the base 34a has a shape having a long length in the axial direction, and has a cylindrical shape as a whole.

The protrusion 34b protrudes from the outer surface of the base 34a toward the outside (the side away from the central axis O) and has a shape having a long length in the axial direction. The protruding portion 34b has a tapered portion in which the amount of protruding outward gradually increases as it faces upward from the rear end of the guide portion 32c. In this embodiment, as shown in Fig. 3, a plurality of protrusions 34b are arranged at equal intervals with the central axis O as the center. In Figs. 1 and 2, only the protrusions 34b positioned on the left and right of the drawing are shown.

When the inner punch 30 is driven by the inner punch driving unit 50, the reference inner circumferential surface 10b precedes the inner circumferential surface 10a of the workpiece 10 by the forging unit 32 that is displaced to reciprocate in the vertical direction. The groove 10c is formed in the reference inner circumferential surface 10b by the groove forming portion 34 which is formed in this manner and is then displaced to reciprocate in the vertical direction. And when the processing of the inner diameter of the workpiece 10 by the inner punch 30 is finished, the punching residue 14 of the workpiece 10 falls downward on the inner circumferential surface 24 of the pedestal 20. do.

The outer punch 40 is disposed outside the inner punch 30. The outer punch 40 has a cylindrical shape and presses the workpiece 10 placed on the outer shape forming portion 22 of the pedestal 20 in the conveying direction. Specifically, at the lower end of the outer punch 40, a pressing portion 42 parallel to a surface orthogonal to the axial direction is formed, and by the pressing portion 42, the workpiece 10 is The periphery is pressed in the conveying direction. Accordingly, the workpiece 10 is expanded so that the outer surface of the workpiece 10 is in close contact with the outer shape forming part 22. This outer punch 40 is independent of the inner punch 30 and can be displaced in the vertical direction. Specifically, the outer punch 40 is driven by an outer punch drive unit (not shown in the drawing) that drives the outer punch 40. In the present embodiment, the outer punch 40 is driven in the conveying direction before the inner punch 30 to press the workpiece 10 to the outer shape forming portion 22.

In addition, the outer punch 40 is provided with a lubricating oil supply flow path 44. The lubricating oil supply passage 44 passes through the outer punch 40 in a direction orthogonal to the axial direction. In this embodiment, the lubricating oil supply passage 44 is formed in four portions at intervals of 90° around the central axis 0. The lubricating oil supplied from the outside of the outer punch 40 through the lubricating oil supply passage 44 is sprayed to the outer surface of the inner punch 30. This lubricating oil rides on the outer surface of the inner punch 30 downward and reaches the inner peripheral surface 10a of the material to be processed 10. Accordingly, friction between the inner punch 30 and the workpiece 10 is reduced. In this embodiment, the lubricating oil is sprayed at a pace once per second.

Next, the inner punch drive unit 50 will be described with reference to FIG. 4.

The inner punch drive unit 50 includes a hydraulic cylinder 500 that can expand and contract in the vertical direction, and a hydraulic system 502 that drives the hydraulic cylinder 500 in the expansion and contraction direction. .

The hydraulic cylinder 500 includes a piston 507, a cylinder body 501 that accommodates it so as to be raised and lowered, and a rod 508, and the piston 507 The cylinder body 501 is loaded in the cylinder body 501 so that the inside of the cylinder body 501 is separated into a head chamber 501a on the upper side and a rod chamber 501b on the lower side. The rod 508 extends downward from the piston 507 beyond the lower end of the cylinder body 501, and the upper end of the inner punch 30 is connected to the lower end 508a of the rod 508. Therefore, in accordance with the expansion and contraction of the hydraulic cylinder 500, that is, the displacement of the piston 507 and the rod 508 in the vertical direction, the inner punch 30 is displaced in the vertical direction.

The hydraulic system 502 includes a hydraulic pump 503, a discharge flow rate adjustment unit 505, a switching valve 510, and a sequence valve. 530, a pressure setting unit 536, a flow rate adjustment valve 540, a flow rate adjustment unit 546, a buffer unit 550, and an initial position adjustment unit 560 It is equipped with.

The hydraulic pump 503 is a variable displacement pump capable of adjusting a discharge flow rate according to an electric signal output from the discharge flow rate adjustment unit 505. This hydraulic pump 503 is connected to a motor 504 capable of adjusting the number of rotations. That is, the discharge flow rate from the hydraulic pump 503 can be adjusted by both the rotation speed of the regulator and the motor 504. The number of revolutions of the regulator and the motor 504, that is, the amount of hydraulic oil discharged from the hydraulic pump 503 is adjusted by the discharge flow rate adjusting unit 505 connected to the hydraulic pump 503 and the motor 504. .

The selector valve 510 is connected to the hydraulic pump 503 through a first flow path 521, and is connected to the head chamber 501a through a second flow path 522, and It is connected to the load chamber 501b through a three passage 523, and is connected to a tank T through a fourth passage 524. The switching valve 510 guides the hydraulic oil discharged from the hydraulic pump 503 to the head chamber 501a through the first flow passage 521 and the second flow passage 522 and returns from the load chamber 501b. The hydraulic oil discharged from the hydraulic pump 503 and the cylinder lowering position 510b that guides the oil to the tank T through the third flow path 523 and the fourth flow path 524 The tank is guided to the load chamber 501b through the flow path 521 and the third flow path 523, and the oil returned from the head chamber 501a is passed through the second flow path 522 and the fourth flow path 524. It is a hydraulic pilot type 2-position selector valve capable of switching the spool between the cylinder pulling positions 510a leading to T).

The selector valve 510 includes a first pilot chamber 511, a second pilot chamber 512, and a spring 513. The spring 513 always presses the spool in the direction in which the spool becomes the cylinder lowering position 510b. For this reason, when the pilot pressure does not act on the first pilot chamber 511, the spool is held at the cylinder lowering position 510b. The first pilot chamber 511 is connected to the first passage 521 through a first pilot line 531, and a first pilot from the first passage 521 through the first pilot line 531 When the pilot pressure is supplied to the seal 511, the pilot pressure resists the pressing force of the spring 513, and the spool is switched to the cylinder raising position 510a. The second pilot chamber 512 is connected to the fourth passage 524 through a second pilot line 532, and a second pilot from the fourth passage 524 through the second pilot line 532 The pilot pressure supplied to the seal 512 pressurizes the spool in the direction in which the spool becomes the cylinder lowering position 510b together with the spring 513.

The sequence valve 530 is installed in the middle of the first pilot line 531 and opens and shuts off the first pilot line 531 by the opening and closing valves. The sequence valve 530 is a setting in which the pressure of the first flow path 521 connected to the head chamber 501a through the primary pressure, that is, the second flow path 522 is set by the pressure setting unit 536 It opens when the pressure is exceeded. More specifically, the inner punch 30 contacts the workpiece 10 and receives resistance from the workpiece 10, so that the inner punch 30 and the piston 507 of the hydraulic cylinder 500 are lowered. When the pressure of the first flow path 521 and the pressure acting on the head chamber 501a increases, and the pressure of the first flow path 521 exceeds the pressure corresponding to the set pressure, the sequence valve 530 Opens. Then, the first pilot line 531 is opened so that the pilot pressure acts on the first pilot chamber 511. Also, at the same time, the hydraulic oil supplied to the first pilot line 531 is also supplied to the second pilot line 532 via a throttle valve 535. Further, the sequence valve 530 is closed when the pressure in the head chamber 501a is less than the set pressure.

The sequence valve 530 of this embodiment is a proportional solenoid valve, and the set pressure of the sequence valve 530 can be adjusted by an external pressure setting unit 536. Since the set pressure of the sequence valve 530 corresponds to a pressing force at which the inner punch 30 presses the workpiece 10, the pressure setting unit 536 corresponds to a “pressing force setting unit”. As shown in Fig. 5, the pressure setting unit 536 includes the amount of displacement of the inner punch 30 in the conveying direction from the position (initial position) where the inner punch 30 first contacted the workpiece 10. As it increases, the set pressure is increased so that the pressing force increases.

The flow adjustment valve 540 is installed in the second pilot line 532. By adjusting the opening degree of the flow rate adjustment valve 540, the flow rate of the hydraulic oil flowing into the second pilot chamber 512, that is, the pilot pressure acting on the second pilot chamber 512 is adjusted. The flow adjustment valve 540 of this embodiment is a proportional electromagnetic valve, and the opening degree of the flow adjustment valve 540 can be adjusted by an external flow adjustment unit 546. When the opening degree of the flow adjustment valve 540 decreases, since the pilot pressure acting on the second pilot chamber 512 decreases, the speed at which the spool returns to the cylinder lowering position 510b decreases, and thus the hydraulic cylinder 500 The speed at which the piston 507 and the inner punch 30 rise is also reduced. In other words, the flow rate adjustment unit 546 constitutes a “speed adjustment unit” that adjusts the speed at which the inner punch 30 is displaced in the separation direction by adjusting the opening degree of the flow rate adjustment valve 540. In this embodiment, the displacement speed of the hydraulic cylinder 500 can be adjusted between 5 and 800 spm by the speed adjusting unit.

The buffer part 550 is installed in the fourth flow path 524 and reduces vibration of the hydraulic oil in each flow path. The buffer unit 550 includes an accumulator 551 capable of accumulating hydraulic oil, a throttle valve 552 provided on the tank T side than the accumulator 551 in the fourth flow path 524, and the throttle. A check valve 553 connected in parallel with the valve 552 is provided.

The initial position adjustment unit 560 is for adjusting the initial positions of the piston 507 and the inner punch 30 in the vertical direction of the hydraulic cylinder 500. The initial position adjustment unit 560 is an adjustment unit including an electromagnetic switching valve 561, a back pressure holding unit 566 including a check valve, and a pilot-type variable flow rate adjustment valve. It has 567. The electromagnetic switching valve 561 is an electronic three-position switching valve that is switched between the three positions of the neutral position 561a, the cylinder lowering position 561b, and the cylinder raising position 561c. The electromagnetic selector valve 561 is connected to the pilot line 564, the second flow passage 522 and the third flow passage 523. The initial positions of the hydraulic cylinder 500 and the inner punch 30 are adjusted by an operator switching the position of the electromagnetic switching valve 561 from the outside. Specifically, the operator sets a position where the lower end of the inner punch 30 contacts the upper end of the workpiece 10 as an initial position.

In addition, pilot check valves 571 and 572 are installed in the second flow passage 522 and the third flow passage 523, respectively, and the pilot port of the valve is a pilot line or tank through a switching valve 573. It is connected to the line.

The pilot check valves 571 and 572 are open together when the rod 508 and the inner punch 30 move up and down, and adjust the position of the lower end of the inner punch 30 by the initial position adjustment unit 560 It is only manipulated to close together. Accordingly, it is possible to adjust the initial position without worrying about the internal leakage of the switching valve 510.

In addition, a relief valve 576 is provided in a flow path 575 branched from the first flow path 521. This relief valve 576 can be used as an unload valve. That is, in the relief valve 576, the oil chamber on the spring side is sequentially connected to the tank line through a pressure reducing valve 577, a throttle valve 578, and a solenoid valve 579. When the solenoid valve 579 is operated to the open position, the relief valve 576 functions as an unload valve by allowing the spring side oil chamber to communicate with the tank. In addition, when the solenoid valve 579 is operated to the closed position, the connection between the oil chamber on the spring side and the tank is cut off, and the relief valve 576 functions as a normal safety valve.

Next, referring to Fig. 4, a mechanism for repeatedly displacing the inner punch 30 up and down using the hydraulic cylinder 500 will be described.

As shown in Fig. 4, in the initial state, the spool of the switching valve 510 is held in the cylinder lowering position 510b by receiving the pressing force of the spring 513. When the hydraulic pump 503 is driven in this state, the hydraulic oil discharged from the hydraulic pump 503 is supplied to the head chamber 501a through the first flow path 521 and the second flow path 522, thereby making the hydraulic cylinder 500 ) Is elongated (piston 507 and rod 508 are displaced downward in Fig. 4), the inner punch 30 is displaced downward, that is, in the conveying direction.

And the inner punch 30, more specifically, when the forged portion 32 collides with the workpiece 10, the inner punch 30 receives resistance from the extra thickness 12 of the workpiece 10, thereby making the inner punch The lowering of 30 and the piston 507 is suppressed, thereby increasing the pressure in the head chamber 501a and the pressure in the first flow path 521 which is the pump line. When this pressure exceeds the set pressure of the sequence valve 530, the sequence valve 530 is opened to open the first pilot line 531, and accordingly, the first pilot chamber 511 through the first pilot line 531 ), pilot pressure is applied. Then, the spool of the switching valve 510 is switched to the cylinder raising position 510a. Accordingly, the hydraulic oil discharged from the hydraulic pump 503 is supplied to the rod chamber 501b through the first flow passage 521 and the third flow passage 523 to contract the hydraulic cylinder 500 (Fig. Because 507 is displaced upward), the inner punch 30 is displaced upward, that is, in the separation direction. Then, since the pressure in the head chamber 501a and the pressure of the first flow path 521 are less than the set pressure of the sequence valve 530, the sequence valve 530 is closed to block the first pilot line 531. Accordingly, when the spool of the switching valve 510 receives the pressing force of the spring 513 and the pilot pressure acting on the second pilot chamber 512, the spool is switched to the cylinder lowering position 510b.

As described above, the piston 507, the rod 508 and the inner punch 30 of the hydraulic cylinder 500 are integrated by automatically repeating the switching between the spool cylinder lowering position 510b and the cylinder raising position 510a. And repeats the vertical displacement. In the meantime, as described above, by the pressure setting unit 536, the set pressure of the sequence valve 530 is adjusted to gradually increase as time elapses from the specified initial value.

Subsequently, the processing step of the workpiece 10 will be described.

First, the material to be processed 10 is placed on the outer shape forming part 22 of the pedestal 20. And the outer punch 40 is driven downward by the outer punch drive part which is omitted from the drawing, and the periphery of the workpiece 10 is pressed downward by the pressing part 42. At this time, the material to be processed 10 is plastically deformed and its outer surface is expanded outward, so that the outer surface of the material to be processed 10 is in close contact with the outer shape forming part 22. Accordingly, the outer shape of the workpiece 10 is formed. And in this state, the workpiece 10 is restrained by the pedestal 20 so as not to be displaced in a direction orthogonal to the conveying direction. This contributes to the improvement of the precision of forging molding by the next inner punch 30.

Subsequently, the operator manually adjusts the position of the lower end of the inner punch 30 by using the initial position adjusting unit 560 so that the lower end contacts the surface of the workpiece 10. As shown in Fig. 5, in this embodiment, the scale indicating the initial position of the lower end of the inner punch 30 is about 41.Omm. Further, the set pressure of the sequence valve 530 (the set pressure in the pressure setting portion) is set to increase until the initial value is about 4.5 MPa, and then gradually reaches about 11 MPa.

In the initial state, the position of the switching valve 510 is maintained at the cylinder lowering position 510b by the pressing force of the spring 513. When the hydraulic pump 503 is driven in this state, since hydraulic oil is supplied to the head chamber 501a of the cylinder body 501, the piston 507, the rod 508, and the inner punch connected to the lower end 508a ( 30) descends integrally, and the tip (forged portion 32) of the inner punch 30 collides with the workpiece 10. At this time, an extra thickness 12 is generated in the workpiece 10. And when the pressure of the first flow path 521, which is raised by the resistance of the inner punch 30 from the extra thickness 12, reaches about 4.5 MPa, which is the initial set pressure of the sequence valve 530, the sequence valve ( 530 is opened, and a pilot pressure acts on the first pilot chamber 511. This pilot pressure switches the spool of the switching valve 510 to the cylinder raising position 510a while resisting the pressing force of the spring 513. Then, since the hydraulic oil discharged from the hydraulic pump 503 is supplied to the rod chamber 501b, the displacement directions of the piston 507 and the inner punch 30 of the hydraulic cylinder 500 are reversed, and these are the workpiece 10 It rises to be separated from Accordingly, when the resistance disappears, the pressure in the head chamber 501a decreases and the pressure in the first flow path 521 is less than about 4.5 MPa, which is the initial set pressure of the sequence valve 530, the sequence valve 530 is Closed to block the first pilot line 531. At this time, the spool of the switching valve 510 is switched to the cylinder lowering position 510b by the pressing force of the spring 513 and the pilot pressure acting on the second pilot chamber 512. Then, since the hydraulic oil discharged from the hydraulic pump 503 is supplied to the head chamber 501a, the piston 507 of the hydraulic cylinder 500 and the inner punch 30 are integrally displaced in the conveying direction (downward). , The inner punch 30 collides with the workpiece 10. According to the above method, the inner punch 30 processes the inner diameter of the workpiece 10 while repeating the collision and separation against the workpiece 10. In addition, in the present embodiment, as shown in Fig. 5, in the period A from the start of the processing of the workpiece 10 by the inner punch 30 to the end, the inner punch 30 is The collision for (10) is repeated 10 times.

In general, as the amount of displacement of the inner punch 30 in the conveying direction increases, that is, as the height position of the lower end of the inner punch 30 decreases, the amount of extra thickness 12 generated in the workpiece 10 is reduced. As it increases, the resistance that the inner punch 30 receives from the workpiece 10 gradually increases. For this reason, for example, when the set pressure of the sequence valve 530 is constant, the amount of displacement of the inner punch 30 in the feed direction (the processing speed of the inner circumferential surface 10a by the inner punch 30) gradually decreases. . Therefore, in this embodiment, as shown in Fig. 5, as time elapses (as the amount of displacement of the inner punch 30 in the feed direction increases), the set pressure of the sequence valve 530 (inner punch 30 The pressure is set in the pressure setting unit 536 so that the pressing force at which) presses the workpiece 10) gradually increases from about 4.5 MPa to about 11 MPa. Therefore, the inner circumferential surface 10a is smoothly processed. Accordingly, productivity is improved. In addition, from Fig. 5, the position where the position of the inner punch is at a minimum and the position at which the inner punch receives the maximum resistance from the workpiece coincide, and the position at which the position of the inner punch becomes maximum. It can be seen that the position at which the resistance of the inner punch from the workpiece is minimized is consistent. In addition, it can be seen that the shape of the line connecting the maximum value of the resistance received from the workpiece by the inner punch substantially matches that of the set pressure in the pressure setting unit.

In the above-described process in which the inner punch 30 processes the inner diameter of the workpiece 10, first, the forged portion 32, which fluctuates in the vertical direction, repeatedly collides against the workpiece 10, so that the workpiece 10 The reference inner circumferential surface 10b is formed, and after that, the groove forming portion 34 which fluctuates in the vertical direction repeats the collision against the workpiece 10 to form a groove 10c on the reference inner circumferential surface 10b. Since the reference inner circumferential surface 10b is an inner circumferential surface of a cross-section in a direction perpendicular to the axial direction of the central axis O is an inner circumferential surface of a uniform shape throughout the axial direction, a groove forming portion ( In the step of forming the grooves 10c by 34), the reduction ratio of the section of the workpiece 10 is always constant, that is, the pressure acting on the protrusions 34b becomes uniform. Therefore, compared to the case of directly forming a groove in the inner peripheral surface 10a of the workpiece 10 without forming the reference inner peripheral surface 10b, the friction generated between the inner punch 30 and the workpiece 10 is reduced.

In addition, the inner punch 30 is displaced while repeating the collision and separation against the workpiece 10, that is, the inner punch 30 presses the workpiece 10 in the conveying direction. Before the resistance received by the inner punch 30 from the extra thickness 12 becomes too large, the inner punch 30 is separated from the workpiece 10, thereby reducing the resistance and moving the workpiece 10 in the conveying direction. In addition to intermittent press-fitting, friction generated between the inner punch 30 and the workpiece 10 is significantly reduced.

Therefore, since the occurrence of seizure on both the forged portion 32 and the groove forming portion 34 is suppressed, a single inner punch 30 is used to prevent the inner circumferential surface 10a of the workpiece 10. Forging and formation of the groove 10c for the reference inner circumferential surface 10b can be performed in a single process. Therefore, the broach process as in the prior art is omitted, and the man-hours for obtaining a desired molded product from the workpiece 10 are reduced. For this reason, the conventional process, that is, the process of installing and fixing the forged intermediate molded product in a broach processing device different from the forging device, is omitted. Accordingly, the processing precision of the groove due to the tolerance of the intermediate molded product is reduced. Since deterioration is avoided, high-precision groove formation is possible.

In addition, the forged portion 32 of this embodiment includes a guide portion 32c extending from the tip of the groove forming portion 34 toward the conveying direction with respect to the conveying direction and having an outer circumferential surface parallel to the conveying direction. Therefore, in the process of processing the workpiece 10 by the inner punch 30, the guide portion 32c is guided by the reference inner circumferential surface 10b, that is, perpendicular to the transfer direction in the guide portion 32c. In a state in which displacement in the direction is suppressed, a groove is formed in the reference inner circumferential surface 10b by the groove forming portion 34 that is displaced along the conveying direction and the separation direction. Therefore, the processing precision of the groove 10c is further improved.

In addition, in the present embodiment, the outer punch 40 is in a state in which the workpiece 10 is pressed against the outer shape forming portion 22, that is, the pedestal 20 so that the workpiece 10 is not displaced in a direction orthogonal to the conveying direction. Since the workpiece 10 is processed by the inner punch 30 in a state constrained by the method, the processing precision of the inner diameter of the workpiece 10 is higher. In addition, in this forging molding apparatus, both the inner diameter and the outer diameter of the workpiece 10 are processed without separating the workpiece 10 from the pedestal 20.

In addition, since the inner punch drive unit 50 of the present embodiment is provided with a speed adjusting unit, the workpiece 10 can be processed while flexibly responding to the material and shape of the workpiece 10.

In addition, it should be thought that embodiment disclosed this time is an illustration in all points, and is not restrictive. The scope of the present invention is indicated by the claims rather than the description of the above-described embodiments, and includes the meanings equivalent to the claims, and all changes within the scope.

For example, in the above embodiment, an example in which the guide portion 32c has an outer circumferential surface parallel to the axial direction is shown, but the guide portion 32c moves from the rear end of the guide portion 32c toward the front end. It may be a shape whose diameter gradually decreases slightly.

In addition, the shape and number of the protrusions 34b of the groove-forming part 34 are not limited to the example shown in the above embodiment. For example, in the case of forming a keyway, there is one protrusion 34b.

In addition, in the present embodiment, an example in which the guide portion 32c and the base 34a have a cylindrical shape, that is, the cross section in the direction orthogonal to the axial direction in the guide portion 32c and the base 34a is circular. The cross-sectional shape of is not limited to a circular shape. For example, the cross section of the guide portion 32c and the base portion 34a may be oval or polygonal.

10; Workpiece
10a; If you give it out
lOb; Standard
10c; home
20; Pedestal
22; External shape
30; Inner punch
32; Forging
32c; Guide
34; Groove formation
34b; projection part
40; Outer punch
44; As a lubricant supply oil
50; Inner punch drive
500; Hydraulic cylinder
501; Cylinder body
502; Hydraulic system
503; Hydraulic pump
504; motor
505; Discharge flow rate adjustment part
510; Changeover valve
510a; Cylinder raising position
510b; Cylinder down position
511; Pilot room 1
512; 2nd pilot room
513; spring
521; 1 euro
522; 2nd euro
523; 3 euros
524; Euro 4
530; Sequence valve
536; Pressure setting part (Pressure setting part)
540; Flow control valve
546; Flow control unit (speed control unit)
550; Buffer
560; Initial position adjustment part

Claims (5)

As a forging molding device,
A pedestal capable of placing a material to be processed having through-holes, and
An inner punch for processing an inner circumferential surface surrounding the through hole of the workpiece, and
The inner punch is displaced in the conveying direction toward the workpiece to collide with the workpiece, and the inner punch is displaced in a separation direction opposite to the conveying direction. By doing so, an inner punch drive unit that repeatedly displaces the inner punch between the separation position separated from the workpiece is provided.
Equipped,
The inner punch,
The inner circumferential surface of the cross section orthogonal to the conveying direction by forging the inner circumferential surface of the material to be processed is formed at a position facing the material to be processed on the pedestal with respect to the conveying direction. A forging portion having a shape of a uniform reference inner circumferential surface over the entire area and forging the inner circumferential surface of the workpiece;
A base having a shape extending along the separation direction from a rear end of the forging part with respect to the conveying direction, and from an outer surface of the base with respect to a direction orthogonal to the axial direction of the base. A groove-forming portion protruding outward and having a protruding portion forming a groove on the reference inner circumferential surface is provided .
Equipped,
The inner punch drive unit,
A hydraulic cylinder connected to the inner punch so that the inner punch can be expanded and contracted in the transport direction and the separation direction, and the inner punch is displaced in the transport direction and the separation direction,
A hydraulic system that drives the hydraulic cylinder in the direction of expansion and contraction.
Equipped,
The hydraulic system,
A sequence valve capable of setting a set pressure corresponding to a pressing force, which is a force by which the inner punch connected to the hydraulic cylinder presses the workpiece,
A pressure setting unit capable of adjusting the set pressure is provided.
Equipped,
The pressure setting unit, in the process of the hydraulic cylinder repeatedly displacing the inner punch between the collision position and the separation position, the transfer of the inner punch from the position where the inner punch first contacted the workpiece A forging forming apparatus for increasing the set pressure so that the pressing force of the inner punch increases as the amount of displacement in the direction increases .
The method of claim 1,
The forging part includes a guide part extending from the tip of the groove-forming part toward the conveying direction with respect to the conveying direction and having an outer circumferential surface parallel to the conveying direction. Molding device.
The method according to claim 1 or 2,
Further comprising an outer punch (outer punch) disposed outside the inner punch,
The pedestal includes an outer circumferential surface of the to-be-processed material and a shape capable of forming the outer shape of the to-be-processed material,
The outer punch is a forging molding apparatus having a shape capable of pressing the workpiece to the outer shape forming portion in the conveying direction so that the workpiece is expanded so that the outer surface of the workpiece is in close contact with the outer shape forming portion.
The method according to claim 1 or 2,
The hydraulic system further includes a speed adjusting unit capable of adjusting a speed at which the inner punch is displaced from the collision position toward the separation position. delete

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