JP5488022B2 - Forging equipment - Google Patents

Description

  The present invention relates to a forging device that is suitably employed for manufacturing an outer ring, a crankshaft, a bearing, a hub, and the like of a constant velocity joint mounted on a vehicle, for example.

  As an apparatus for forging and manufacturing an outer ring of a constant velocity joint mounted on a vehicle, for example, a device described in Patent Document 1 is known. The apparatus described in Patent Document 1 includes a die having a molding recess and a punch, and presses a workpiece (molding material) placed in the molding recess of the die with a punch, thereby extruding forward and setting up. Forging is performed by processing, backward extrusion, and the like.

  When the forging is performed by warm forging, in each of the above-described processing steps, as shown in FIG. 4, (a) a water-soluble lubricant 30 is applied to the forming recess 11 and the punch 20 of the die 10. (B) a workpiece placement step in which the workpiece W is placed in the molding recess 11 of the die 10; (c) a molding step in which the punch 20 is pressed against the workpiece W; and (d) a workpiece with the knockout pin 40. A cycle of a projecting process for projecting W and (e) a transport process for transporting the workpiece W to the next process is repeated. FIG. 4 shows the case of backward extrusion.

JP 2008-188633 A

  By the way, when warm forging is performed as described above, in the (d) projecting step, the workpiece W may jump up before the molded workpiece W is ejected by the knockout pin 40. When the workpiece W jumps, the workpiece W cannot be gripped at a predetermined position by the gripping device on the production line, so that the workpiece W is abnormally conveyed and the productivity is deteriorated.

  The occurrence of jumping of the workpiece W is caused by using the water-soluble lubricant 30 because (a) in the lubricant application process, if an oil-based lubricant is used, it may burn at the temperature during the forging process. Presumed. That is, when the water-soluble lubricant 30 is used, water in the water-soluble lubricant 30 evaporates at a temperature during the forging process, and water vapor is generated. The water vapor is generated in a sealed space between the molding recess 11 and the workpiece W, and the space becomes high temperature and high pressure when the workpiece W is pressed by the punch 20. For this reason, when the water content of the water-soluble lubricant 30 is steamed, an extremely large force for jumping the workpiece W is generated in the space. Therefore, it is conceivable to provide grooves and holes for releasing the water vapor in the die 10 and the knockout pin 40. However, since the jumping of the work W occurs before the work W is pushed out by the knockout pin 40, it is not possible to completely take measures. .

  In addition, in the case of performing hot forging at a higher temperature than that of warm forging, the pressure of the water vapor is further increased, and thus the frequency of occurrence of jumping of the workpiece W as described above is increased. The same problem occurs not only when the outer ring of the constant velocity joint is manufactured but also when the crankshaft, the bearing, the hub, and the like are manufactured.

  This invention is made | formed in view of the said situation, and makes it the subject which should be solved to provide the forging apparatus which can aim at the improvement of productivity by preventing the jumping of a workpiece | work.

  The structural feature of the invention according to claim 1 that solves the above-described problem includes a die having a molding recess and a punch that presses a workpiece disposed in the molding recess, and the molding recess is being forged. In the forging device for forming the workpiece disposed in the molding recess by warm forging or hot forging after applying a water-soluble lubricant that evaporates moisture at a temperature of An undercut recess that restricts jumping is provided.

  In the present invention, if the end portions on both sides of the undercut concave portion in the workpiece insertion direction and the drawing direction are made to be stepped, both the die and the workpiece are likely to be damaged. Is preferred. In other words, when the stepped shape is used, when the workpiece material is fluidly deformed by the pressing of the punch, it becomes difficult to smoothly flow, and thus surface defects are likely to occur in the molded workpiece. On the other hand, the life of the die is shortened because the edge portion of the stepped shape is easily damaged.

  Further, the depth of the undercut recess can be appropriately set in consideration of the size and weight of the workpiece, the pressure of water vapor generated from the water-soluble lubricant, and the like. If the depth of the undercut recess is too small, the effect of preventing the workpiece from jumping cannot be obtained. On the other hand, if the depth of the undercut concave portion is excessively increased, the workpiece after molding cannot be protruded when protruding with a knockout pin or the like, or it remains as a scratch or wrinkle on the surface of the portion protruding from the undercut concave portion. Therefore, the depth of the undercut concave portion is set such that when the workpiece after molding is protruded from the molding concave portion with a knockout pin or the like, the portion protruding to the undercut concave portion is squeezed by the die and remains as a shape. This may be set as a reference. In this way, adverse effects on accuracy can be reduced.

  Further, the length of the undercut recess (work drawing direction) can be appropriately set in consideration of the depth of the molding recess, the portion where the undercut recess is provided, and the like. In this case, when the workpiece after molding is protruded from the molding recess with a knockout pin or the like, the pressure of water vapor generated from the water-soluble lubricant decreases with the movement of the workpiece. What is necessary is just to enable it to maintain the engagement state (hook state) with a undercut recessed part to the place where the jump of a workpiece | work does not generate | occur | produce. In other words, the length of the undercut concave portion can be set in consideration of the moving distance of the workpiece capable of maintaining the engagement state (the hooked state) between the portion protruding from the undercut concave portion of the workpiece and the undercut concave portion. . In addition, the undercut recessed part should just be provided in at least one part of the circumferential direction of the shaping | molding recessed part.

  The structural feature of the invention according to claim 2 is the forging device according to claim 1, wherein the forming recess has a shaft portion forming surface for forming a portion to be a shaft portion of the workpiece, and more than the shaft portion. A large-diameter portion molding surface for molding a portion having a large diameter, and the undercut concave portion is provided on the large-diameter portion molding surface.

  The structural feature of the invention according to claim 3 is that in the forging device according to claim 1 or 2, the undercut recess is continuously provided over the entire circumference in the circumferential direction of the forming recess. .

  A structural feature of the invention according to claim 4 is the forging device according to any one of claims 1 to 3, wherein the undercut concave portion is on a direction side in which the molded workpiece is removed from the molding concave portion. , Having a first tapered surface that gradually decreases in diameter in the direction of extraction.

  The structural feature of the invention according to claim 5 is the forging device according to any one of claims 1 to 4, wherein the undercut concave portion is opposite to a direction in which the workpiece after molding is pulled out of the molding concave portion. It has a 2nd taper surface which becomes a small diameter gradually toward a direction side on the direction side in the opposite direction to this extraction direction.

  The structural feature of the invention according to claim 6 is the forging device according to any one of claims 1 to 5, wherein the knockout pin or the die that projects the molded workpiece from the molding recess is An escape passage for escaping water vapor generated from the water-soluble lubricant during the forging process is provided.

  According to the first aspect of the present invention, the die forming concave portion is provided with the undercut concave portion for restricting the jumping of the workpiece. As a result, when the workpiece is forged, a portion of the workpiece projects into the undercut recess to form an overhang portion. For this reason, when a force that causes the workpiece to jump due to the water vapor of the water-soluble lubricant is generated, the workpiece force is generated by the catching force generated between the overhang portion formed on the workpiece and the undercut recess of the die. Jumping is regulated. Accordingly, it is possible to reliably prevent the workpiece from jumping before the molded workpiece is ejected with a knockout pin or the like, so that it is possible to avoid a workpiece conveyance abnormality and improve productivity.

  According to the second aspect of the present invention, the molding recess has a shaft molding surface that molds a portion that becomes the shaft portion of the workpiece and a large-diameter portion molding surface that molds a portion having a larger diameter than the shaft portion. And the undercut recessed part is provided in the large diameter part molding surface. That is, the undercut recess is provided on the large-diameter portion molding surface having a larger diameter than the shaft-portion molding surface. As a result, compared to the case where the undercut recess is provided on the shaft forming surface, the workpiece material is more likely to flow radially outward when performing forging, and the overhang to the undercut recess becomes better. The occurrence of surface defects can be suppressed. Further, since the diameter of the undercut concave portion is larger than that in the case where the undercut concave portion is provided on the shaft forming surface, the catching force between the undercut concave portion and the workpiece can be increased. Therefore, it is possible to more reliably prevent the workpiece from jumping.

  Moreover, when a shaft part molding surface and a large-diameter part molding surface are provided in the molding recess, the large-diameter part molding surface is provided on the direction side in which the molded workpiece is removed from the molding recess. Therefore, when the molded workpiece is ejected with a knockout pin or the like, the water vapor generated from the water-soluble lubricant applied to the surface facing the molding recess and the workpiece is opposite to the insertion direction of the knockout pin (shaft portion). Since it flows to the molding surface side), it is possible to prevent the water vapor escape path from being blocked by providing the undercut recess on the molding surface of the large diameter portion.

  According to the invention which concerns on Claim 3, the undercut recessed part is continuously provided over the circumferential direction perimeter of the shaping | molding recessed part. Thereby, it becomes possible to more reliably prevent the workpiece from jumping.

  According to the invention which concerns on Claim 4, an undercut recessed part has a 1st taper surface which becomes a small diameter gradually in the direction which extracts the workpiece | work after shaping | molding from a shaping | molding recessed part. Thereby, when projecting the molded workpiece with a knockout pin or the like, the workpiece can be smoothly projected. Moreover, since the angle of the corner | angular part where the wall surface of the shaping | molding recessed part of a die | dye and a 1st taper surface become large (obtuse angle), damage to a corner | angular part is suppressed and durability improves.

  According to the invention of claim 5, the undercut recess has a second taper surface that gradually decreases in diameter in the direction opposite to the direction in which the workpiece after molding is removed from the molding recess. Have. As a result, when performing forging, the workpiece material easily flows smoothly in the direction opposite to the direction in which the workpiece is removed from the molding recess, so that the occurrence of surface defects on the workpiece can be suppressed. The effect of the present invention is particularly effective when the workpiece is subjected to a centering process.

  According to the sixth aspect of the present invention, the knockout pin or die that projects the molded workpiece from the engagement recess is provided with an escape passage for escaping water vapor generated from the water-soluble lubricant during the forging process. Thereby, since the pressure of the water vapor | steam generate | occur | produced from the water-soluble lubricant can be reduced, the workpiece | work protruded with a knockout pin can be smoothly moved to a predetermined position.

It is sectional drawing which shows the principal part of the die | dye of the forging apparatus which concerns on embodiment. It is an expanded sectional view which expands and shows the A section of FIG. It is a figure which shows the knockout pin of the forging apparatus which concerns on embodiment, Comprising: (a) is sectional drawing which follows an axial direction, (b) is the front view seen from the front end side. It is a schematic diagram which shows each process in the case of performing warm forging, (a) is a lubricant application process, (b) is a workpiece placement process, (c) is a forming process, (d) is a protruding process, (e ) Indicates a transport process.

  Hereinafter, an embodiment in which the forging device of the present invention is embodied will be described with reference to the drawings. The forging device of this embodiment is used for manufacturing an outer ring for a constant velocity joint in which a shaft portion and a cup portion are integrally formed, and is used for forward extrusion processing (shafting step). This forging device is similar to the forging device shown in FIGS. 4 (a) to 4 (e), the die 10 having the forming recess 11, the punch 20 that presses the workpiece W arranged in the forming recess 11, and after the forming The knockout pin 40 that projects the workpiece W from the engagement recess 11 is provided, but the configurations of the die 10 and the knockout pin 40 are different. Therefore, first, a schematic configuration of the entire forging apparatus of the present embodiment will be briefly described with reference to FIG.

  The die 10 is fixed to the base 10a with the opening of the molding recess 11 facing upward. The molding recess 11 includes a shaft molding surface 12 that molds a portion to be a shaft portion of the workpiece W, a medium diameter molding surface 13 that molds a portion having a larger diameter than the shaft portion, and a medium diameter molding surface 13. Has a large-diameter portion molding surface 14 for molding a portion having a large diameter (see FIG. 4A). The shaft portion molding surface 12 is positioned on the most bottom side of the molding recess 11, and the large diameter portion molding surface 14 is positioned on the most opening side of the molding recess 11. The shaft portion molding surface 12 and the medium diameter portion molding surface 13, and the medium diameter portion molding surface 13 and the large diameter portion molding surface are each connected by a tapered surface. A water-soluble lubricant 30 sprayed from the nozzle 31 is applied to the molding recess 11. In addition, a knockout pin 40 is provided at the bottom of the die 10 to push the workpiece W after molding from the molding recess 11 (see FIG. 4D). The knockout pin 40 will be described in detail later.

  The punch 20 is fixed to a movable base 20a provided above the die 10 so as to be vertically movable. When the movable base 20a is lowered, the punch 20 is inserted in a state where the tip end is aligned with the molding recess 11 of the die 10. A water-soluble lubricant 30 sprayed from the nozzle 32 is applied to the tip of the punch 20.

  In addition, the workpiece | work W arrange | positioned in the shaping | molding recessed part 11 is hold | gripped and conveyed by the holding apparatus (not shown) provided on the manufacturing line.

  Next, the configuration of the die 10 of this embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view showing a main part of a die 10 of a forging device according to an embodiment. FIG. 2 is an enlarged cross-sectional view showing an A portion of FIG. 1 and 2, the direction in which the molded workpiece W is pulled out from the molding recess 11 (the direction in which the workpiece W protrudes with the knockout pin 40) is the arrow X direction (the left direction in FIGS. 1 and 2).

  As described above, the molding concave portion 11 of the die 10 of the present embodiment has the shaft portion molding surface 12, the medium diameter portion molding surface 13, and the large diameter portion molding surface. And the undercut recessed part 15 which controls the jump of the workpiece | work W is provided in the axial direction substantially center part of the large diameter part molding surface 14, as shown in FIG.1 and FIG.2. The undercut recess 15 is formed in a ring shape so as to be continuous over the entire circumference in the circumferential direction of the large-diameter portion molding surface 14. The undercut concave portion 15 includes a straight portion 15a located at the axially central portion, and a first tapered surface that is located on one axial end side (arrow X direction side) of the straight portion 15a and gradually decreases in diameter toward the one end side. 15b and a second tapered surface 15c which is located on the other axial end side (arrow Y direction side) of the straight portion 15a and gradually decreases in diameter toward the other end side. The straight portion 15a, the first tapered surface 15b, and the second tapered surface 15c are each formed to extend in the circumferential direction with a constant width.

  An insertion hole 16 through which the knockout pin 40 is inserted is provided at the bottom of the die 10. The insertion hole 16 is formed coaxially with the molding recess 11 and communicates with the bottom of the molding recess 11.

  Next, the knockout pin 40 will be described with reference to FIG. 3A is a cross-sectional view taken along the axial direction of the knockout pin 40, and FIG. 3B is a front view of the knockout pin 40 viewed from the tip side. The knockout pin 40 is formed in a long rod shape, and is located on one end side and fixed to an actuator (not shown), and a columnar support extending from the base portion 41 to the other end side. Part 42. A plurality of relief grooves 43 extending in the axial direction are provided on the outer peripheral surface of the support portion 42 at equal intervals in the circumferential direction.

  The knockout pin 40 has a main body portion 42 inserted into an insertion hole 16 (see FIG. 1) provided at the bottom of the die 10 so that the molded workpiece W protrudes from the engaging recess 11 by the operation of the actuator. It is configured. When the support portion 42 of the knockout pin 40 is inserted into the insertion hole 16, the water content of the water-soluble lubricant 30 is between the relief groove 43 provided on the outer peripheral surface of the support portion 42 and the wall surface of the insertion hole 16. The escape passage of the water vapor generated in the molding recess 11 by evaporation of is formed.

  As shown in FIG. 4, the forging device of the present embodiment configured as described above includes (a) a lubricant application step, (b) a workpiece placement step, (c) a molding step, and (d) a workpiece. The forge forming (forward extrusion process) of the workpiece W is performed by sequentially performing the protruding step and (e) the workpiece conveying step. That is, in the (a) lubricant application step, the water-soluble lubricant 30 sprayed from the nozzles 31 and 32 is applied to the molding recess 11 and the tip of the punch 20. In the next (b) work placement step, the work W gripped and transported by the gripping device is placed and placed in the molding recess 11 of the die 10.

  In the next (c) molding step, the tip of the punch 20 is inserted into the molding recess 11 of the die 10 by lowering the movable base 20a, and the workpiece W is pressed with a predetermined pressure. Thereby, the workpiece W arranged in the molding recess 11 is pushed forward (downward) of the punch 20, and the shaft portion is molded by the shaft portion molding surface 12. At the same time, a projecting portion is formed by projecting a part of the large-diameter portion of the workpiece W to an undercut concave portion 15 provided on the large-diameter portion molding surface 14 of the molding concave portion 11. At this time, the second taper surface 15c that gradually decreases in diameter toward the other end side in the axial direction (arrow Y direction side) is provided at the other axial end portion of the undercut recess 15 so that the workpiece material is It flows smoothly and the occurrence of surface defects on the workpiece W is suppressed. Thereafter, the punch 20 is raised by the raising of the movable base 20a.

  At this time, high-pressure water vapor is generated between the facing surfaces of the molding recess 11 and the workpiece W due to evaporation of water of the water-soluble lubricant 30 applied to the molding recess 11 at a temperature during the forging process, A force that causes the workpiece W to jump and jump due to the high-pressure steam is applied. However, in this embodiment, the engagement force (hook) generated between the overhang portion formed on the large-diameter portion of the workpiece W and the undercut concave portion 15 provided on the large-diameter portion molding surface 14 of the molding concave portion 11. Force) reliably prevents the workpiece W from jumping.

  Thereafter, (d) in the workpiece projecting step, the knockout pin 40 is raised by the operation of the actuator, and the molded workpiece W is ejected upward from the engaging recess 11. As a result, the workpiece W protruding upward disappears due to squeezing when the projecting portion formed in the large-diameter portion passes through the large-diameter portion molding surface 14 of the molding recess 11. At this time, since the first taper surface 15b having a gradually decreasing diameter toward one axial end (arrow X direction side) is provided at one axial end of the undercut recess 15, the workpiece W is a knockout pin. 40 is smoothly ejected. Further, breakage of the corner portion where the wall surface of the molding recess 11 and the first tapered surface 15b intersect is also suppressed.

  When the knockout pin 40 is raised, the high-pressure water vapor in the molding recess 11 is released to the outside through the relief groove 43 (escape passage) provided in the support portion 42 of the knockout pin 40. The inside of the recess 11 is depressurized. Thereby, the workpiece | work W protruded with the knockout pin 40 moves smoothly to a predetermined position.

  Thereafter, the workpiece W that has been forged by the forging device (forward extrusion processing) and moved to a predetermined position is gripped by the gripping device and transported to the next process ((e) transporting step).

  As described above, according to the forging device of the present embodiment, since the undercut recess 15 is provided in the molding recess 11 of the die 10, the water content of the water-soluble lubricant 30 when the workpiece W is forged. It is possible to reliably prevent the workpiece W from jumping due to steaming. Thereby, the conveyance abnormality of the workpiece | work W can be avoided and productivity can be aimed at. Since the undercut recessed part 15 of this embodiment is continuously provided over the circumferential direction perimeter of the shaping | molding recessed part 11, it becomes possible to prevent the workpiece | work W from jumping more reliably.

  And since the undercut recessed part 15 of this embodiment is provided in the large diameter part shaping | molding surface 14 of the shaping | molding recessed part 11, when performing a forge forming, a workpiece | work raw material flows easily to radial direction outward, and an undercut Since the protrusion to the recess 15 is good, the occurrence of surface defects can be suppressed. Moreover, since the diameter of the undercut recessed part 15 can be enlarged and the engagement force (hook force) of the undercut recessed part 15 and the workpiece | work W can be enlarged, the jumping of the workpiece | work W can be prevented more reliably. It becomes possible. Furthermore, since the undercut recess 15 is provided on the large-diameter portion molding surface 14 located on the opposite side of the shaft portion molding surface 12, it is formed between the relief groove 43 of the knockout pin 40 and the shaft portion molding surface 12. It is possible to prevent the escape passage of the steam from being blocked.

  Moreover, since the undercut recessed part 15 of this embodiment has the 1st taper surface 15b, when projecting the workpiece | work W after shaping | molding with the knockout pin 40, it can project the workpiece | work W smoothly. Furthermore, since the angle of the corner where the wall surface of the molding recess 11 and the first taper surface 15b intersect becomes large (obtuse angle), breakage of the corner can be suppressed, and durability is improved.

  Moreover, since the undercut recessed part 15 of this embodiment has the 2nd taper surface 15c, when performing forge molding, a workpiece | work raw material flows smoothly in the direction opposite to the direction which extracts the workpiece | work W from the shaping | molding recessed part 11. FIG. Since it becomes easy, generation | occurrence | production of the surface defect of the workpiece | work W can be suppressed. This effect is particularly effective when the workpiece W is centered as in the present embodiment.

  In the present embodiment, the relief groove 43 is provided in the knockout pin 40, thereby providing an escape passage for water vapor generated from the water-soluble lubricant 30 during the forging process. Thereby, since the pressure of the water vapor | steam generate | occur | produced from the water-soluble lubricant 30 can be reduced, the workpiece | work W protruded with the knockout pin 40 can be smoothly moved to a predetermined position.

  In addition, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the meaning of this invention.

  For example, in the above embodiment, the undercut recess 15 is continuously provided over the entire circumference in the circumferential direction of the molding recess 11, but the undercut recess is provided only in a part (one place) in the circumferential direction of the molding recess 11. Alternatively, undercut recesses may be provided at a plurality of locations in the circumferential direction of the molding recess 11.

  In addition, the forging device of the above embodiment is for a shafting process in which a workpiece W is subjected to forward extrusion to form a shaft portion, but in addition, a large diameter that performs upsetting to form a large diameter portion. The present invention can also be applied to a forging device for a part forming process and a forging device for forming a cup part that performs a backward extrusion process to form a cup part.

  Further, in the above embodiment, the forging device used for manufacturing the outer ring of the constant velocity joint is exemplified, but the present invention is also applied to a forging device used for manufacturing a crankshaft, a bearing, a hub, etc. of equipment installed in a vehicle. The invention can be applied.

  DESCRIPTION OF SYMBOLS 10 ... Die, 11 ... Molding recessed part, 12 ... Shaft part molding surface, 13 ... Medium diameter part molding surface, 14 ... Large diameter part molding surface, 15 ... Undercut recessed part, 15a ... Straight part, 15b ... 1st taper surface, 15c ... 2nd taper surface, 20 ... Punch, 30 ... Water-soluble lubricant, 40 ... Knockout pin, 41 ... Base part, 42 ... Support part, 43 ... Escape groove.

Claims (6)

A die having a molding recess, and a punch that presses a workpiece disposed in the molding recess, and the molding recess is coated with a water-soluble lubricant that evaporates water at a temperature during a forging process, and then molded. In the forging device for forming the workpiece arranged in the recess by warm forging or hot forging,
The forging device, wherein the forming recess is provided with an undercut recess for restricting jumping of the workpiece. In claim 1,
The molding recess has a shaft molding surface that molds a portion to be a shaft portion of the workpiece, and a large-diameter portion molding surface that molds a portion having a larger diameter than the shaft portion,
The undercut recess is provided on the molding surface of the large diameter portion. In claim 1 or 2,
The forging device, wherein the undercut recess is provided continuously over the entire circumference of the forming recess. In any one of Claims 1-3,
The undercut recess has a first taper surface that gradually decreases in diameter in the direction of pulling out the workpiece after molding from the molding recess. In any one of Claims 1-4,
The undercut recess has a second taper surface that gradually decreases in diameter in a direction opposite to the direction in which the workpiece after molding is pulled out from the molding recess. apparatus. In any one of Claims 1-5,
A forging device characterized in that a knockout pin or the die for projecting the workpiece after molding from the molding recess is provided with an escape passage for releasing water vapor generated from the water-soluble lubricant during the forging process.

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