KR20150042139A - Apparatus for molding by forging - Google Patents

Abstract

The present invention is to provide an apparatus for molding by forging and a molding method to form a high-precision groove for an inside diameter and improve productivity. An apparatus for molding by forging, comprises: a base (20); an inner punch (30); an inner punch operation unit (50) which repetitively displaces the inner punch (30) between a hitting point where the inner punch (30) hits a material to be processed (10); and a separation point where the inner punch (30) moves away from the material to be processed (10). The inner punch comprises a forging part (32) which forges an inner peripheral face of the material to be processed, and a groove forming portion (34). The forging part (32) is formed on a point facing the material to be processed (10), and has a shape which makes the inner peripheral face a base inner peripheral face (10b) by forging an inner peripheral face (10a) of the material to be processed (10). The groove forming portion (34) has a shape which can form a groove (10c) on the base inner peripheral face (10b) by protruding externally from a rear end of the forging part (32) against a transport direction.

Description

[0001] APPARATUS FOR MOLDING BY FORGING [0002]

The present invention relates to a forging molding apparatus.

BACKGROUND ART Conventionally, a keyway, a spline, or the like (hereinafter, simply referred to as a " groove ") is formed in an inner diameter of a workpiece (workpiece) having an inner peripheral surface forged (hereinafter referred to as " groove "). For example, in Patent Document 1, a ring-shaped intermediate molded product (intermediate molded product) having a through hole (through hole) at the center thereof is first molded by forging a disc-shaped material to be processed, A method for molding a final molded article (final molded article) by forming a groove by broaching is disclosed.

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

In the molding method described in Patent Document 1, forging and broaching must be carried out sequentially in separate facilities. Therefore, the number of steps required to obtain a desired final molded product from the material to be processed is There is a problem that it is difficult to improve the productivity. Specifically, in order to carry out the forming method described in Patent Document 1, generally, first, the material to be processed is sandwiched between holding portions of a forging device for forging the material to be processed, and the sandwiching material to be sandwiched is forged, The molded article is molded. Thereafter, the intermediate molded article is separated from the holding portion of the forging apparatus, and the intermediate molded article is sandwiched between the holding portions of the broaching apparatus. Then, the inner peripheral surface of the intermediate molded product is cut by a broach to form a groove. Thus, the above-described molding method is accompanied by a very complicated operation.

In addition, since the molding of the intermediate molded product and the formation of the grooves in the intermediate molded product are each performed by a separate device, there is a possibility that the accuracy of forming the groove is lowered. Specifically, there is a case where the intermediate molded product is sandwiched between the gripping portions of the broaching apparatus in a slightly offset position from the normal posture due to the tolerance of the intermediate molded product formed by forging the material to be processed by the forging apparatus. In this case, the processing accuracy of the broaching process is remarkably reduced.

It is an object of the present invention to provide a forging molding apparatus and a molding method which can easily achieve both of the improvement of productivity and the formation of a high-precision groove with respect to an inner diameter.

Means for Solving the Problems In order to solve the above problems, the present inventors conceived that the formation of the inner circumferential surface with respect to the material to be processed and the formation of the grooves with respect to the inner circumferential surface are performed by a single inner punch. However, when the formation of the inner peripheral surface and the formation of the groove in the material to be processed are performed at the same time, the friction generated between the inner punch and the material to be processed becomes large, and seizure may occur in the inner punch.

Therefore, the present invention provides a forging apparatus comprising: a pedestal capable of placing a material to be processed having a through hole; an inner punch for machining an inner circumferential surface surrounding the through hole of the material to be processed; The inner punch is repeatedly displaced between the collision position where the inner punch collides with the material to be processed by the displacement of the inner punch in the transport direction and the intermittent position where the inner punch moves away from the material to be processed by being displaced in the direction away from the transport direction Wherein the inner punch includes a forging portion for forging an inner circumferential surface of the material to be processed and a groove forming portion formed at the rear of the forging portion in the feeding direction, The workpiece placed on the pedestal is opposed to the workpiece And the inner peripheral surface of the cross section in the direction orthogonal to the conveying direction is formed as a uniform reference inner peripheral surface over the entire conveying direction by forging the inner peripheral surface of the material to be processed, And a protruding portion protruding outward from a rear end of the forging portion with respect to a conveying direction so as to form a groove in the reference inner circumferential surface.

According to the present invention, since the reference inner circumferential surface is formed on the workpiece by the forging portion and the groove is formed on the reference inner circumferential surface by the groove forming portion, and the inner punch repeatedly collides with the workpiece Since the friction generated between the inner punch and the work piece is greatly reduced by the displacement, the occurrence of squeezing against both of the forged portion and the groove forming portion is suppressed, The forging of the inner circumferential surface of the work and the formation of the grooves with respect to the reference inner circumferential surface can be performed in a single step. More specifically, the forging portion forms a reference inner circumferential surface uniform in the workpiece in the direction orthogonal to the conveying direction over the entirety of the conveying direction, and a groove is formed in the reference inner circumferential surface by the groove forming portion Therefore, in the step of forming the grooves on the reference inner circumferential surface, the reduction rate of the cross-sectional area of the material to be processed is constant, that is, the pressure acting on the groove forming portion becomes uniform, so that friction generated between the inner punch and the material to be processed is reduced. Further, since the inner punch is displaced while repeatedly colliding with and disengaging from the material to be processed, that is, from the extra thickness of the material to be processed, which is generated when the inner punch presses the material to be processed in the feeding direction, The inner punch is separated from the material to be processed so as to reduce the resistance and press-fit the material to be processed in the feeding direction, and the friction generated between the inner punch and the material to be processed is greatly reduced. Therefore, occurrence of squeezing of both the forging portion and the groove forming portion is suppressed, so that forging of the inner circumferential surface of the material to be processed and formation of the groove for the reference inner circumferential surface can be performed in a single step. Therefore, the conventional broaching process is omitted, and the airflow from the material to be processed until the desired molded product is obtained is reduced. Therefore, the conventional process, that is, the step of installing and repairing the intermediate molded product after forging in a broaching apparatus different from that of the forging apparatus is omitted, thereby avoiding a reduction in the processing accuracy of the groove due to the tolerance of the intermediate molded product Therefore, it is possible to form the groove with high precision.

In this case, the forging portion preferably includes a guide portion extending from the tip end of the groove forming portion with respect to the conveying direction toward the conveying direction and having an outer circumferential surface parallel to the conveying direction.

In this way, in the state in which the guide portion is guided by the reference inner circumferential surface, that is, the displacement in the direction orthogonal to the conveying direction in the guide portion is suppressed, The grooves are formed in the reference inner circumferential surface by the grooved portions, so that the processing accuracy of the grooves is further improved.

Further, the present invention may further comprise an outer punch disposed on the outer side of the inner punch, wherein the pedestal includes an outer shape forming section that surrounds the outer peripheral surface of the material to be processed and forms an outer shape of the material to be processed And the outer punch has a shape capable of pressing the material to be processed in the feeding direction with respect to the outer forming part so that the outer surface of the material to be processed is brought into close contact with the outer forming part by expanding the material to be processed desirable.

In this way, the outer diameter is processed in addition to the inner diameter of the material to be processed without detaching the material to be processed from the pedestal, and the outer punch is expanded so that the outer surface of the material to be processed is in close contact with the outer- Since the outer punch has a shape capable of pressing the material to be processed in the conveying direction with respect to the outer shape forming portion, the outer punch is in a state in which the material to be processed is pressed against the outer shape forming portion, The processing accuracy of the inner diameter of the material to be processed is further improved by processing the material to be processed by the inner punch in a state in which the displacement in the direction orthogonal to the axis is constrained by the pedestal.

Further, according to the present invention, the inner punch drive unit is configured to move the inner punch in a direction in which the inner punch contacts the workpiece for the first time as the amount of displacement of the inner punch in the transfer direction increases, It is preferable to provide a pressing force setting section for increasing the pressing force.

In this way, it is possible to smoothly process the inner peripheral surface of the material to be processed by the inner punch. Generally, as the amount of displacement of the inner punch in the transport 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 feeding direction (the processing speed of the inner peripheral surface by the inner punch) gradually decreases. On the other hand, according to the present invention, as the amount of displacement of the inner punch in the feeding direction increases, the pressing force gradually increases, so that the inner peripheral surface can be smoothly machined.

Further, in the present invention, it is preferable that the inner punch driving section includes a speed adjusting section capable of adjusting a speed at which the inner punch is displaced from the impact position toward the intermittent position.

In this way, the material to be processed can be processed while flexibly coping with the material and the 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 which can easily achieve both of the formation of the groove with high accuracy with respect to the inner diameter and the improvement of the productivity.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view of a forging and molding apparatus according to an embodiment of the present invention; FIG.
Fig. 2 is a view schematically showing the forging and molding apparatus of Fig. 1. Fig.
Fig. 3 is a bottom view of the inner punch in the forging and forming apparatus of Fig. 1;
4 is a view showing a configuration of the inner punch driving unit.
5 is a graph showing the relationship between the inner punch and the resistance acting on the inner punch.

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

As shown in Figs. 1 and 2, the forging apparatus of the present embodiment includes a pedestal 20 on which a work piece (work piece) 10 can be placed, an inner punch 20, (30), and an outer punch (40). The present forging apparatus includes an inner punch driving unit (inner punch driving unit) 50 for driving the inner punch 30 as shown in Fig. In this forging molding apparatus, a bevel gear, a differential side gear, a hypoid ring gear, a spur gear, a sleeve yoke, and other deformed shapes Shaped body can be molded. 1 shows a state before the inner punch 30 and the outer punch 40 come into contact with the material to be processed 10 on the left side of the center axis O of the inner punch 30, The outer punch 40 presses the material to be processed 10 against the pedestal 20 and the inner punch 30 is in a state where the inner diameter of the material to be processed 10 is being machined Is shown. 2, the outer punch 40 presses the material to be processed 10 against the pedestal 20 and the inner punch 30 processes the inner diameter of the material to be processed 10 on the left side of the central axis O And the state in which machining of the inner diameter of the workpiece 10 by the inner punch 30 is completed is shown on the right side of the center axis 0. In the following description, the lower side of FIG. 1 and FIG. 2 is referred to as a lower side or a front side, and the upper side of FIG. 1 and FIG. 2 is referred to as an upper side or a rear side, .

The material to be processed 10 is an annular member having an inner circumferential surface 10a surrounding a through hole. Concretely, the center of a cold-forged, hot-tempered or hot forged material is pierced, thereby forming a workpiece 10 having a through-hole. In addition, the position of the inner peripheral surface 10a before machining is indicated by a chain double-dashed line on the right side of the central axis O in Fig. 1 and on the left side of the central axis 0 in Fig.

The pedestal 20 is provided with an outer shape forming portion 22 which is capable of placing the material to be processed 10 and forming the outer shape of the material 10 to be processed. The outer shape forming portion 22 has a concave shape surrounding the periphery of the material 10 to be processed. The pedestal 20 of the present embodiment has an inner circumferential surface 24 surrounding a space for allowing insertion of the inner punch 30 and the punching residue 14 (see FIG. 2) of the material to be processed 10. The lower end of the outer shape forming portion 22 is connected to the upper end of the inner peripheral surface 24. [

The inner punch 30 is a tool (tool) for machining the inner peripheral surface 10a of the material to be processed while being displaced repeatedly in the vertical direction as shown in Figs. More specifically, the inner punch 30 is displaced in the conveying direction (the conveying direction) (downward in FIGS. 1 and 2) toward the material to be processed 10 by the inner punch 30, (The upper side in Fig. 1 and Fig. 2) by the inner punch 30 in the opposite direction to the conveying direction, The inner circumferential surface 10a of the material to be processed is machined. This operation of the inner punch 30 is realized by the inner punch driving part 50. [ This point will be described later in detail. Specifically, the inner punch 30 includes a forged portion (forging portion) 32 for forging the inner peripheral surface 10a of the material to be processed 10, and a keyway, spline, and the like And a groove forming portion (groove forming portion) 34 for forming a groove of the groove portion 34.

The forged portion 32 is formed at a position facing the material to be processed 10 placed on the pedestal 20. As shown in Fig. 2, the forging portion 32 forms a reference inner circumferential surface (reference inner circumferential surface) 10b in the material to be processed 10 by forging the inner circumferential surface 10a of the material to be processed 10. The reference inner circumferential surface 10b is an inner circumferential surface of a cross section in a direction orthogonal to the axial direction of the central axis O is an inner circumferential surface having a uniform shape over the entire area in the axial direction. 3, the forging portion 32 includes a flat portion 32a parallel to a plane perpendicular to the axial direction, and a flat portion 32b extending upward from the flat portion 32a in the axial direction And a guide portion 32c having an inclined portion 32b having a shape that is parallel to the axial direction (conveying direction) and an outer peripheral surface (outer peripheral surface) parallel to the axial direction (conveying direction). The flat portion 32a is formed at the front end (lower end in Fig. 1) of the inner punch 30. [ The inclined portion 32b has a shape such that the outer diameter gradually increases from the outer edge of the flat portion 32a toward the upper side. The guide portion 32c extends upward from the upper end of the inclined portion 32b and extends from the tip end (lower end in FIG. 1) of the groove forming portion 34 to the groove forming portion 34, in other words, And extends along 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 the present embodiment, the flat portion 32a and the inclined portion 32b have a conical trapezoidal shape, and the guide portion 32c has a cylindrical shape. The inner peripheral surface 10a of the material to be processed 10 is processed to be the reference inner peripheral surface 10b by the guide portion 32c.

The groove forming portion 34 is formed immediately after the forging portion 32 (just above the forging portion 32 in FIG. 1) with respect to the conveying direction and has a reference inner circumferential surface 10b formed by the forging portion 32 ). The groove forming portion 34 includes a base portion 34a and a protruding portion 34b.

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

The protruding portion 34b protrudes from the outer side of the base portion 34a toward the outer side (the side away from the central axis O) and has a shape which is long in the axial direction. The protruding portion 34b has a tapered portion that gradually increases toward the outside from the rear end of the guide portion 32c toward the upward direction. In the present embodiment, as shown in Fig. 3, a plurality of projecting portions 34b are arranged at equal intervals about the center axis O as a center. In Figs. 1 and 2, only protruding portions 34b located on the left and right of the figure are shown.

When the inner punch 30 is driven by the inner punch driving unit 50, the reference inner circumferential surface 10b is positioned at the inner circumferential surface 10a of the material to be processed 10 by the forged portion 32 displaced to reciprocate in the up- And a groove 10c is formed in the reference inner circumferential surface 10b by a groove forming portion 34 that is displaced to reciprocate in the up-and-down direction. When the machining of the inner diameter of the material 10 to be processed by the inner punch 30 is completed, the punching residue 14 of the material to be processed 10 falls downward on the inner side of 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 presses the material to be processed 10 which is cylindrical and placed on the outer shape forming portion 22 of the pedestal 20 in the conveying direction. More specifically, a pressing portion 42 is formed at the lower end of the outer punch 40 in parallel with a plane perpendicular to the axial direction. The pressing portion 42 presses the workpiece 10 Thereby pressing the peripheral edge portion in the transport direction. The material to be processed 10 is expanded so that the outer surface of the material to be processed 10 is brought into close contact with the outer shape forming portion 22. The outer punch (40) can be displaced in the vertical direction independently of the inner punch (30). Specifically, the outer punch 40 is driven by an outer punch driving section (not shown in the figure) that drives the outer punch 40 concerned. In the present embodiment, the outer punch 40 is driven in the feeding direction in advance of the inner punch 30 so as to press the material to be processed 10 to the outer shape forming section 22. [

A lubricating oil supply passage (lubricating oil supply passage) 44 is formed in the outer punch 40. The lubricant supply passage 44 penetrates the outer punch 40 in a direction orthogonal to the axial direction. In the present embodiment, the lubricant oil supply passages 44 are formed in four parts at intervals of 90 degrees with the center axis 0 as the center. The lubricating oil supplied from the outside of the outer punch 40 through the lubricating oil supply passage 44 is injected onto the outer surface of the inner punch 30. The lubricating oil rides downward on the outer surface of the inner punch 30 and reaches the inner peripheral surface 10a of the material 10 to be processed. Therefore, the friction between the inner punch 30 and the material to be processed 10 is reduced. In this embodiment, the lubricating oil is injected in a single pace per second.

Next, the inner punch driving unit 50 will be described with reference to Fig.

The inner punch drive unit 50 includes a hydraulic cylinder 500 that is vertically extendable and contractible 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 and a cylinder body 501 for accommodating the piston 507 so as to be able to lift the cylinder 507 and a rod 508. The piston 507, Is mounted in the cylinder body 501 such that 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 beyond the lower end of the cylinder body 501 from the piston 507 and the upper end of the inner punch 30 is connected to the lower end 508a of the rod 508. [ The inner punch 30 is displaced in the vertical direction 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 hydraulic system 502 includes a hydraulic pump 503, a discharge flow rate adjusting unit (discharge flow rate adjusting unit) 505, a switching valve 510, a sequence valve, A flow rate adjusting valve 540, a flow rate adjusting unit 546, a buffering unit 550, an initial position adjusting unit 560, a pressure adjusting unit 530, a pressure setting unit 536, .

The hydraulic pump 503 is a variable displacement pump in which the discharge flow rate can be adjusted in accordance with an electric signal output from the discharge flow rate adjustment unit 505. The hydraulic pump 503 is connected to a motor 504 capable of adjusting the rotation speed. That is, the discharge flow rate from the hydraulic pump 503 is adjustable by both the speeds of the regulator and the motor 504. The amount of rotation of the regulator and the motor 504, that is, the amount of hydraulic fluid from the hydraulic pump 503 is adjusted by the hydraulic pump 503 and the discharge flow rate adjuster 505 connected to the motor 504 .

The switching valve 510 is connected to the hydraulic pump 503 through a first flow path (first oil path) 521 and is connected to the head room 501a through a second flow path 522, And is connected to the load chamber 501b via the third flow path 523 and is connected to the tank T via the fourth flow path 524. [ The switching valve 510 is a valve that introduces the working oil discharged from the hydraulic pump 503 to the head room 501a through the first flow path 521 and the second flow path 522, A cylinder lowering position 510b for leading the oil to the tank T via the third and fourth flow paths 523 and 524 and the hydraulic oil discharged from the hydraulic pump 503 at the first The oil returning from the head chamber 501a to the load chamber 501b through the oil passage 521 and the third oil passage 523 via the second oil passage 522 and the fourth oil passage 524 via the tank Position switching valve that can switch a spool between a cylinder lifting position (cylinder lifting position) 510a leading to a cylinder head (T)

The switching valve 510 is provided with a first pilot chamber (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 comes to the cylinder lowering position 510b. Therefore, when no pilot pressure acts on the first pilot chamber 511, the spool is held in the cylinder lowering position 510b. The first pilot chamber 511 is connected to the first flow line 521 through a first pilot line 531 and receives a first pilot signal from the first channel 521 through the first pilot line 531, When the pilot pressure is supplied to the chamber 511, the pilot pressure is switched to the cylinder lifting position 510a against the biasing force of the spring 513. The second pilot chamber 512 is connected to the fourth flow path 524 through a second pilot line 532 and is connected to the second pilot line 532 from the fourth flow path 524 via a second pilot line 532. [ The pilot pressure supplied to the chamber 512 presses the spool in the direction in which the spool is in the cylinder lowering position 510b together with the spring 513.

The sequence valve 530 is provided in the middle of the first pilot line 531 and opens and closes the first pilot line 531 by its opening and closing valves. The sequence valve 530 is set such that the pressure of the first flow path 521 connected to the head room 501a via the primary pressure or the second flow path 522 is set by the pressure setting section 536 It is opened when pressure is exceeded. More specifically, the inner punch 30 comes into contact with the material to be processed 10 and receives resistance from the material to be processed 10, so that the falling of the inner punch 30 and the piston 507 of the hydraulic cylinder 500 The sequence valve 530 is closed when the pressure acting on the head chamber 501a and the pressure of the first flow path 521 rise and the pressure of the first flow path 521 exceeds the pressure corresponding to the set pressure, Is opened. Then, the first pilot line 531 is opened and the pilot pressure acts on the first pilot chamber 511. At the same time, the operating oil supplied to the first pilot line 531 is also supplied to the second pilot line 532 via the throttle valve 535. [ The sequence valve 530 is closed when the pressure in the head chamber 501a falls below (lower) the set pressure.

The sequence valve 530 of the present embodiment is a proportional electromagnetic type (proportional electromagnetic type) valve, and the set pressure of the sequence valve 530 can be adjusted by an external pressure setting section 536. Since the set pressure of the sequence valve 530 corresponds to the pressing force of the inner punch 30 to press the work piece 10, the pressure setting portion 536 corresponds to the " pressing force setting portion ". 5, the pressure setting unit 536 sets the amount of displacement of the inner punch 30 in the feeding direction from the position (initial position) where the inner punch 30 first contacts the material 10 to be processed The set pressure is increased so that the pressing force is increased.

The flow control valve 540 is provided in the second pilot line 532. The flow rate of the hydraulic fluid flowing into the second pilot chamber 512, that is, the pilot pressure acting on the second pilot chamber 512, is adjusted by adjusting the degree of opening of the flow control valve 540. The flow regulating valve 540 of the present embodiment is a proportional electronic valve, and the opening of the flow regulating valve 540 is adjustable by an external flow regulator 546. The pilot pressure acting on the second pilot chamber 512 is reduced so that the speed at which the spool returns to the cylinder lowering position 510b is reduced, The speed at which the piston 507 and the inner punch 30 of the piston 503 ascend is also reduced. In other words, the flow rate adjusting section 546 constitutes a " speed adjusting section " for adjusting the speed at which the inner punch 30 is displaced in the separating direction by adjusting the opening degree of the flow rate adjusting valve 540. [ In this embodiment, the displacement speed of the hydraulic cylinder 500 is adjustable between 5 and 800 spm by the speed adjusting unit.

The buffering portion 550 is provided in the fourth flow path 524 and reduces the vibration of the hydraulic fluid in each flow path. The buffering portion 550 includes an accumulator 551 capable of accumulating operating fluid and a throttle valve 552 installed in the fourth passage 524 on the side of the tank T relative to the accumulator 551, And a check valve 553 connected in parallel with the valve 552.

The initial position adjustment unit 560 is for adjusting the initial position of the piston 507 and the inner punch 30 in the up and down direction in the hydraulic cylinder 500. The initial position adjusting section 560 includes an electromagnetic switching valve 561, a back pressure maintaining section 566 including a check valve, an adjusting section (adjustment section) including a pilot type variable flow rate adjusting valve, (567). The electromagnetic switching valve 561 is an electromagnetic three-position switching valve that is switched between three positions, that is, a neutral position 561a, a cylinder lowering position 561b, and a cylinder lifting position 561c. The electromagnetic switching valve 561 is connected to the pilot line 564, the second flow path 522 and the third flow path 523. And the position of the electromagnetic switching valve 561 is externally switched by the operator so that the initial positions of the hydraulic cylinder 500 and the inner punch 30 are adjusted. Specifically, the operator sets the position where the lower end of the inner punch 30 contacts the upper end of the material to be processed 10 as the initial position.

Pilot check valves 571 and 572 are provided on the second flow path 522 and the third flow path 523 and the pilot port of the valve is connected to the pilot line or the tank Line.

The pilot check valves 571 and 572 are opened when the rod 508 and the inner punch 30 move up and down and the position of the lower end of the inner punch 30 is adjusted by the initial position adjusting unit 560 Only when it is closed together. Accordingly, the initial position adjustment can be performed without worrying about the internal leakage of the switching valve 510.

A relief valve 576 is provided in the flow path (oil path) 575 branched from the first flow path 521. This relief valve 576 can be used as an unload valve. That is, the oil chamber on the spring side of the relief valve 576 is connected to the tank line through a depressurization valve 577, a throttle valve 578 and an electromagnetic valve 579 in sequence When the solenoid valve 579 is operated to the open position, the relief valve 576 functions as an unloading valve by allowing the oil chamber on the spring side to communicate with the tank. Further, when the solenoid valve 579 is operated to the closed position, the connection between the oil chamber at the spring side and the tank is blocked, and the relief valve 576 functions as a normal safety valve.

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

4, in the initial state, the spool of the switching valve 510 is held in the cylinder lowering position 510b by the pressing force of the spring 513. When the hydraulic pump 503 is driven in this state, the hydraulic fluid 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, (The piston 507 and the rod 508 are displaced downward in Fig. 4), the inner punch 30 is displaced in the downward direction, that is, in the transport direction.

The inner punch 30 receives a resistance from the extra thickness 12 of the material to be processed 10 so that the inner punch 30 can be easily removed from the inner punch 30, The pressure in the head chamber 501a and the pressure in the first flow path 521, which is a pump line, are raised. When the 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 ) Is applied to the pilot pressure. Then, the spool of the switching valve 510 is switched to the cylinder lifting position 510a. The hydraulic fluid discharged from the hydraulic pump 503 is supplied to the load chamber 501b through the first flow path 521 and the third flow path 523 to shrink the hydraulic cylinder 500 507) upward, the inner punch 30 is displaced upward (i.e., in the intermittent direction). The sequence valve 530 is closed to block the first pilot line 531 because the pressure in the head chamber 501a and the pressure of the first flow path 521 are below the set pressure of the sequence valve 530. [ Accordingly, 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, so that the spool is switched to the cylinder lowering position 510b.

The piston 507 of the hydraulic cylinder 500 and the rod 508 and the inner punch 30 of the hydraulic cylinder 500 are integrally rotated by automatically repeating switching of the spool between the cylinder lowering position 510b and the cylinder lifting position 510a, And the displacement in the vertical direction is repeated. As described above, the set pressure of the sequence valve 530 is adjusted by the pressure setting unit 536 so that it gradually increases with time from the specified initial value.

Subsequently, a processing step (processing step) of the material to be processed 10 will be described.

The workpiece 10 is placed on the outer shape forming portion 22 of the pedestal 20 first. The outer punch 40 is driven downward by the outer punch drive unit omitted in the drawing, and the peripheral portion of the material to be processed 10 is pressed downward by the pressurizing unit 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 brought into close contact with the outer shape forming portion 22. Thus, the contour of the material to be processed 10 is formed. In this state, the work piece 10 is restrained by the pedestal 20 so as not to be displaced in the direction orthogonal to the conveying direction. This contributes to an improvement in accuracy of the forging molding by the following inner punch 30.

Subsequently, the operator manually adjusts the position of the lower end of the inner punch 30 so that the lower end thereof is in contact with the surface of the material to be processed 10 by using the initial position adjusting unit 560. 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 41.0 mm. The set pressure (set pressure in the pressure setting portion) of the sequence valve 530 is set so that the initial value is about 4.5 MPa, and then gradually increases until it reaches about 11 MPa.

In the initial state, the position of the switching valve 510 is held in the cylinder lowering position 510b by the urging force of the spring 513. [ When the hydraulic pump 503 is driven in this state, the hydraulic fluid is supplied to the head chamber 501a of the cylinder main body 501, so that the piston 507, the rod 508, and the inner punch 508a connected to the lower end 508a 30 are integrally lowered so that the tip end (forging portion 32) of the inner punch 30 impacts the material 10 to be processed. At this time, an extra thickness 12 is generated in the material 10 to be processed. When the pressure of the first flow path 521 in which the inner punch 30 is raised by the resistance received from the extra thickness 12 reaches about 4.5 MPa which is the initial set pressure of the sequence valve 530, 530 are opened, so that the pilot pressure acts on the first pilot chamber 511. This pilot pressure switches the spool of the switching valve 510 to the cylinder lifting position 510a while being resistant to the pressing force of the spring 513. The displacement direction of the piston 507 and the inner punch 30 of the hydraulic cylinder 500 is reversed because the hydraulic fluid discharged from the hydraulic pump 503 is supplied to the load chamber 501b, As shown in Fig. When the pressure in the head chamber 501a is lowered and the pressure of the first flow path 521 is lower than the initial set pressure of the sequential valve 530 of about 4.5 MPa, the sequence valve 530 And closes 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 biasing force of the spring 513 and the pilot pressure acting on the second pilot chamber 512. The piston 507 and the inner punch 30 of the hydraulic cylinder 500 are integrally displaced in the feeding direction (downward) because the hydraulic fluid discharged from the hydraulic pump 503 is supplied to the head chamber 501a , The inner punch 30 is collided with the material 10 to be processed. According to the above-described procedure, the inner punch 30 processes the inner diameter of the material to be processed 10 while repeating the collision with the material to be processed 10 and the separation. 5, in the period (A) from the start of machining of the material 10 to be processed by the inner punch 30 to the end of the machining of the material 10, the inner punch 30, The collision with the robot 10 is repeated 10 times.

Generally, as the amount of displacement of the inner punch 30 in the transport direction increases, that is, as the height position of the lower end of the inner punch 30 becomes lower, the amount of extra thickness 12 generated in the material 10 to be processed The resistance received by the inner punch 30 from the material 10 to be processed gradually increases. Therefore, when the set pressure of the sequence valve 530 is constant, for example, the amount of displacement of the inner punch 30 in the transfer direction (the processing speed of the inner peripheral surface 10a by the inner punch 30) gradually decreases . 5, the set pressure of the sequence valve 530 (as the amount of displacement of the inner punch 30 in the feeding direction increases) (the inner punch 30 ) Is gradually increased from about 4.5 MPa to about 11 MPa by setting the pressure in the pressure setting unit 536. [ Therefore, the inner peripheral surface 10a is smoothly processed. As a result, productivity is improved. 5 that the positions at which the positions of the inner punches become the minimum and the positions at which the resistance of the inner punch received from the materials to be processed coincide with each other become maximum and the positions where the positions of the inner punches become the maximum And the position where the resistance received by the inner punch from the material to be processed becomes minimum coincides with each other. In addition, it can be seen that the shape of the line connecting the maximum value of the resistance received from the material to be processed by the inner punch substantially agrees with that of the set pressure in the pressure setting section.

In the above process in which the inner punch 30 processes the inner diameter of the material to be processed 10, the forging portion 32, which fluctuates in the vertical direction, first collides against the material 10 to be processed, A groove 10c is formed in the reference inner circumferential surface 10b by repeating the collision of the groove forming portion 34 in the up and down direction with the material to be processed 10 after the reference inner circumferential surface 10b is formed. Since the inner circumferential surface of the reference inner circumferential surface 10b is a uniform inner circumferential surface in the axial direction orthogonal to the axial direction of the central axis O, 34, the sectional reduction rate of the material to be processed 10 is constant at all times, that is, the pressure acting on the projecting portion 34b becomes uniform. The friction generated between the inner punch 30 and the material 10 to be processed is reduced as compared with the case where grooves are formed directly on the inner peripheral surface 10a of the material to be processed 10 without forming the reference inner circumferential surface 10b.

The inner punch 30 is displaced while repeatedly colliding with the material 10 to be processed so that the inner punch 30 is displaced in the direction in which the material 10 to be processed The inner punch 30 is moved away from the material to be processed 10 before the resistance received by the inner punch 30 from the excess thickness 12 becomes excessively large so that the material to be processed 10 is moved in the feeding direction The friction generated between the inner punch 30 and the material to be processed 10 is greatly reduced, as well as intermittently press-fitting.

The occurrence of seizure on both of the forged portion 32 and the groove forming portion 34 is suppressed so that the use of the single inner punch 30 is effective for preventing the occurrence of seizure on both sides of the inner peripheral surface 10a of the material 10 to be processed 10 The forging and the formation of the groove 10c with respect to the reference inner peripheral surface 10b can be performed in a single step. Therefore, the conventional broaching process is omitted, and the airflow until the desired product is obtained from the material to be processed 10 is reduced. Therefore, the conventional process, that is, the step of installing and repairing the intermediate molded product after forging in a different broaching apparatus than the forging apparatus is omitted, and accordingly, the processing accuracy of the groove due to the tolerance of the intermediate molded product So that a high-precision groove can be formed.

The forging portion 32 of the present embodiment further includes a guide portion 32c extending from the tip end of the groove forming portion 34 in the conveying direction toward the conveying direction and having an outer circumferential surface parallel to the conveying direction In the step of machining the material 10 to be processed by the inner punch 30, the guide portion 32c is guided by the reference inner circumferential surface 10b, that is, in the guide portion 32c, A groove is formed in the reference inner peripheral surface 10b by the groove forming portion 34 displaced along the conveying direction and the separating direction. Therefore, the machining accuracy of the groove 10c is further improved.

In the present embodiment, the outer punch 40 is provided on the pedestal 20 so as not to be displaced in the state where the material to be processed 10 is pressed against the outer shape forming portion 22, that is, the material 10 to be processed is perpendicular to the conveying direction. The processing accuracy of the inner diameter of the material to be processed 10 is further enhanced since the material 10 to be processed is processed by the inner punch 30. [ In addition, in the present forging apparatus, both the inner diameter and the outer diameter of the material to be processed 10 are processed without separating the materials to be processed 10 from the pedestal 20.

Further, since the inner punch driving unit 50 of the present embodiment is provided with the speed adjusting unit, the material to be processed 10 can be processed while flexibly coping with the material and the shape of the material 10 to be processed.

It should also be understood that the embodiments disclosed herein are illustrative and non-restrictive in all respects. The scope of the present invention is not limited to the description of the above-described embodiment, but includes all modifications within the meaning and scope equivalent to the claims of the present invention.

For example, in the above-described embodiment, the guide portion 32c has a shape having an outer peripheral surface parallel to the axial direction. However, the guide portion 32c may be formed in such a manner that the guide portion 32c But may be a shape that gradually becomes smaller in diameter.

The shape and the number of the projecting portions 34b of the groove forming portion 34 are not limited to the examples shown in the above-mentioned embodiment. For example, in the case of forming the keyway, the number of the projections 34b is one.

In the present embodiment, the guide portion 32c and the base portion 34a are circular in cross section in the direction orthogonal to the axial direction of the guide portion 32c and the base portion 34a. However, Sectional shape is not limited to a circle. For example, the cross section of the guide portion 32c and the base portion 34a may be elliptical or polygonal.

10; Workpiece
10a; Inner circumferential surface
lOb; Reference inner circumferential surface
10c; home
20; Pedestal
22; The outer-
30; Inner punch
32; Forging part
32c; Guide portion
34; Groove forming part
34b; projection part
40; Outer punch
44; Lubricant supply line
50; The inner punch driving part
500; Hydraulic cylinder
501; Cylinder body
502; Hydraulic system
503; Hydraulic pump
504; motor
505; The discharge flow rate adjuster
510; Switching valve
510a; Cylinder lifting position
510b; Cylinder lowering position
511; The first pilot chamber
512; The second pilot chamber
513; spring
521; The first euros
522; The second euros
523; Third Euro
524; The fourth channel
530; Sequence valve
536; Pressure setting section (pressing force setting section)
540; Flow regulating valve
546; Flow rate adjuster (speed adjuster)
550; Buffer
560; Initial position adjustment section

Claims (5)

As a forging device,
A pedestal capable of placing a work piece (work piece) having a through hole (through hole) therein,
An inner punch for machining an inner circumferential surface surrounding the through hole of the material to be processed,
And the inner punch is displaced in a separating direction (a separating direction) opposite to the conveying direction, and a collision position where the inner punch collides with the material to be processed by displacement in a conveying direction (conveying direction) An inner punch driving unit (inner punch driving unit) for repeatedly displacing the inner punch is provided between the inner punch driving unit
Respectively,
Wherein the inner punch includes a forging portion (forging portion) for forging an inner peripheral surface of the material to be processed, and a groove forming portion (groove forming portion) formed in the rear of the forging portion in the feeding direction,
Wherein the forging portion is formed at a position facing the workpiece to be placed on the pedestal with respect to the feeding direction and by forging the inner circumferential face of the workpiece so that the inner circumferential face of the cross- (Reference inner circumferential surface) uniform over the whole range of the direction of the guide surface,
Wherein the groove forming portion is protruded outward from a rear end of the forging portion with respect to the conveying direction and has a shape capable of forming a groove on the reference inner circumferential surface.
The method according to claim 1,
Wherein the forging portion includes a guide portion (guide portion) extending from a front end (tip end) of the groove forming portion with respect to the conveying direction toward the conveying direction and having an outer circumferential surface (outer circumferential surface) parallel to the conveying direction, Molding device.
3. The method according to claim 1 or 2,
Further comprising an outer punch disposed on the outer side of the inner punch,
The pedestal includes an outer shape forming portion (outer shape forming portion) which surrounds the outer peripheral surface of the material to be processed and which is capable of forming an outer shape of the material to be processed,
Wherein the outer punch has a shape capable of pressing the material to be processed in the conveying direction with respect to the outer shape forming portion so that the material to be processed is extended so that the outer surface of the material to be processed is in close contact with the outer shape forming portion.
3. The method according to claim 1 or 2,
Wherein the inner punch drive unit includes a pressing force setting unit that increases the pressing force by which the inner punch presses the work material as the amount of displacement of the inner punch from the position where the inner punch contacts the work material for the first time in the feeding direction of the inner punch increases, (Pressing force setting unit).
3. The method according to claim 1 or 2,
Wherein the inner punch driving portion includes a speed adjusting portion (speed adjusting portion) capable of adjusting a speed at which the inner punch is displaced from the impact position toward the spacing position.

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