JP2006212703A - Device and method for forming shaft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft forming device capable of forming a shaft out of a metal plate in one process. <P>SOLUTION: The shaft forming device 100 comprises: a die 30 in which a through hole 32 having the same inside diameter as the contour of a shaft 10 and a metal plate 20 to be worked is supported by a top face of the through hole 32; a punch 40 having the same contour as the inside diameter of the shaft 10, which presses the metal plate 20 supported by the top face of the through hole 32 into the through hole 32; and a knockout 50 which is provided inside the through hole 32 of the die 30 to roll the metal plate 20 pushed to a tip of the punch 40 to a side face of the shaft 10 by applying the back pressure to the metal plate 20 while moving to the distal side of the through hole 32 opposing the tip of the punch 40. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a shaft forming apparatus and a shaft forming method for forming a hollow shaft protruding from a metal plate by pressing the metal plate.

Conventionally, a method for forming a hollow shaft protruding from a metal plate by pressing the metal plate is known. According to this prior art, the first step of half-cutting the metal plate by press working and the protrusion obtained in the first step are held on the die, the punch is pushed into the protrusion, and the protrusion is A shaft is formed by the second step of pushing backward in the opposite direction to pushing (see, for example, Patent Document 1).
Japanese Patent No. 3475551 (FIGS. 1-4)

  However, the prior art described above requires at least two steps to form the shaft. Accordingly, there is a problem that it is difficult to reduce the cost required for processing.

  In order to solve the above-described problem, in the first embodiment of the present invention, a shaft forming apparatus that forms a hollow shaft protruding from a metal plate by pressing the metal plate, the same as the outer shape of the shaft. A through hole having an inner diameter of the die, a die supporting the metal plate to be processed on the upper surface of the through hole, and a metal plate having the same outer shape as the inner diameter of the shaft and supported on the upper surface of the through hole. A punch that pushes into the through hole and a die that is provided inside the through hole of the die. When the punch pushes the metal plate into the through hole, it moves against the metal plate while moving to the back of the through hole while facing the tip of the punch. There is provided a shaft forming apparatus including a knockout that rolls a metal plate pushed by the tip of the punch onto the side surface of the shaft by applying back pressure. According to such a shaft forming apparatus, the shaft can be formed from the metal plate in one step by forging the metal plate between the punch and the knockout.

  The shaft forming apparatus may further include pressing means that is provided around the punch and holds the metal plate supported in a region other than the through hole of the die so as not to float from the die. According to such a shaft forming apparatus, the shape of the metal plate in a portion other than the shaft can be accurately maintained in the state before the shaft is formed.

  In the above-described shaft forming apparatus, the die may be rounded on the entire circumference of the edge of the through hole. According to such a shaft forming apparatus, the metal plate can be smoothly drawn into the die by punching.

  In the above-described shaft forming apparatus, the tip of the punch may be gently raised from the periphery toward the center, and the tip of the knockout may be gently depressed from the periphery toward the center. According to such a shaft forming apparatus, the metal plate compressed by punching and knockout can be smoothly rolled toward the side surface of the shaft.

  In a state where the die supports the metal plate on the upper surface of the through hole, the knockout may stand by at a position lower than the upper surface of the through hole by a distance corresponding to 1/3 of the plate thickness of the metal plate. According to such a shaft forming apparatus, it is possible to prevent the metal plate material from being pushed out around the metal plate at the edge of the through hole, which is generated when the die and the knockout are flush with each other. it can.

  In the above-described shaft forming apparatus, the punch may process the inner diameter of the shaft uniformly in the length direction of the shaft. According to such a shaft forming apparatus, stress concentration can be prevented and the strength of the shaft can be improved.

  According to the second aspect of the present invention, there is provided a shaft forming method for forming a hollow shaft protruding from a metal plate by pressing the metal plate, wherein the through hole having the same inner diameter as the outer shape of the shaft is provided. A preparatory step of placing a metal plate to be processed on the upper surface of the through hole of the formed die, and a metal plate supported on the upper surface of the through hole by a punch having the same outer shape as the inner diameter of the shaft to the through hole While pushing, with the knockout provided in advance inside the through hole of the die facing the tip of the punch, by applying back pressure to the metal plate with knockout, the metal plate pushed to the tip of the punch There is provided a shaft forming method including a punching and forging step of rolling on a side surface of a shaft. According to such a shaft forming method, the shaft can be formed from the metal plate in one step by forging the metal plate between the punch and the knockout.

  In the above-described shaft forming method, in the preparation step, the knockout may wait at a position lower than the upper surface of the through hole by a distance corresponding to 1/3 of the plate thickness of the metal plate. According to such a shaft forming method, it is possible to prevent extrusion of the metal plate material around the die and knockout, and at the same time, prevent breakage of the metal plate at the edge of the through hole. it can.

  Further, in the above shaft forming method, a notch step for forming three or more linear notches formed radially from the center of the top surface of the shaft using a punch and a die, and a burring punch and a burring die are used. A rising step of pushing and bending a plurality of sector-shaped sections defined by the incision to stand the sections upright in the height direction of the shaft, and a tip portion of the section standing upright in the axial direction using a bending punch and a bending die The method may further include a bending step of forming an upright portion that is radially bent with respect to the axis and is upright with respect to the top surface of the section, and a horizontal portion that extends radially from the tip of the upright portion. Thereby, the structure for mounting | wearing with another member further can be formed in the front-end | tip of the axis | shaft formed in the metal plate. Therefore, the member that prevents the member attached to the shaft from falling off can be directly attached to the shaft.

  In the shaft forming method, it is preferable that the tip of the horizontal portion is formed so as to be positioned inside a region defined by extending the side surface of the shaft in the axial direction. This prevents the horizontal portion from interfering with the member when the shaft is inserted through the member to be mounted.

  Further, in the shaft forming method, the bending step further includes an intermediate bending step of bending the tip portion of the upstanding section to an intermediate angle of less than 90 °, and a final bending step of bending the tip portion to 90 ° to obtain a horizontal portion. Can be provided. Thereby, the processing amount in a single process is suppressed, and the limited material supplied from the top surface of the shaft can be bent without breaking. Accordingly, the horizontal portion can be reliably formed.

  Further, in the bending step of the shaft forming method, a part of the bending die comes into contact with the upright portion from the side to prevent deformation. As a result, the upright portion of the section is prevented from being irregularly deformed, and a substantially cylindrical upright portion is formed.

  Further, in the bending step of the shaft forming method, it is preferable to prevent deformation of the top surface by bringing a bending receiver into contact with the back surface of the top surface from the inside of the shaft. As a result, the top surface of the shaft is prevented from being deformed in the bending step, and an upright portion that can be smoothly mounted with other members is formed.

  Further, in the shaft forming method, the distance between the horizontal portion and the top surface is substantially equal to the thickness of the C-ring attached to the upright portion. As a result, the C-ring for preventing the member attached to the shaft from coming off can be attached without a gap. Therefore, there is no backlash in the member mounted on the shaft and its operation.

  The above summary of the invention does not enumerate all the necessary features of the present invention, and sub-combinations of these feature groups can also be the invention.

  Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the scope of claims, and all combinations of features described in the embodiments are included. It is not necessarily essential for the solution of the invention.

FIG. 1 shows a perspective view of a shaft product 99 with a shaft 10 formed in the present embodiment. The shaft 10 is a hollow shaft formed by projecting from the metal plate 20 by pressing the metal plate 20. In this embodiment, the thickness of the metal plate 20 is 1.2 mm, and the material of the metal plate 20 is cold rolled steel plate (SECC). Further, the outer diameter of the shaft 10 is φ7.4 mm, and the length of the shaft 10 is about 8 mm.
FIG. 2 shows a cross section of the shaft product 99. The thickness of the shaft 10 is, for example, about 0.35 mm on the top surface and about 0.15 mm on the side surface.

  3 and 4 show a cross section of the shaft forming device 100. FIG. 3 shows a state before the metal plate 20 is pressed, and FIG. 4 shows a state where the shaft 10 is formed by pressing the metal plate 20. The shaft forming apparatus 100 includes a die 30, a punch 40, a knockout 50, and a pressing means 60. The die 30 is formed with a through hole 32 having the same inner diameter as the outer shape of the shaft 10. The punch 40 has the same outer shape as the inner diameter of the shaft 10 and has a movable range from above the through hole 32 to the inside of the through hole 32. The knockout 50 is provided inside the through hole 32 and is held in a state facing the tip of the punch 40. In this embodiment, the diameter of the punch 40 is φ7.1, and the diameter of the knockout 50 is φ7.4. The material of the die 30, the punch 40, and the knockout 50 is, for example, a super hard material. The material of the pressing means 60 is alloy tool steel (SKD).

  The shaft forming apparatus 100 configured as described above processes the shaft 10 in the following procedure. First, in the preparation step, the metal plate 20 to be processed is placed on the upper surface of the through hole 32 of the die 30 and is pressed by the pressing means 60 so that the metal plate 20 positioned around the through hole 32 does not float from the die 30. In the preparation step, the knockout 50 stands by at a position lower than the upper surface of the through hole 32 by a distance corresponding to 1/3 of the plate thickness of the metal plate 20. For example, since the thickness of the metal plate 20 of the present embodiment is 1.2 mm, the knockout 50 stands by at a position lower than the upper surface of the through hole 32 by 0.4 mm. Next, in the punching / forging step, back pressure is applied to the metal plate 20 with a knockout 50 facing the tip of the punch 40 while the metal plate 20 is pushed into the through hole 32 with the punch 40. The back pressure of the knockout 50 is a load capable of forging the metal plate 20 and is set based on the material properties of the metal plate 20 and the diameter of the shaft 10. The punch 40 pushes the metal plate 20 into the through hole 32 with a pressure larger than the back pressure of the knockout 50. Thereby, the metal plate 20 pushed by the front-end | tip of the punch 40 is rolled on the side surface of the axis | shaft 10, and the axis | shaft 10 is formed.

  According to the present embodiment, by forging the metal plate 20 between the punch 40 and the knockout 50, the shaft product 99 including the shaft 10 can be formed from the metal plate 20 in one step. Therefore, the shaft 10 can be machined at a low cost. Further, in the preparation step, the knockout 50 is made to stand by at a position lower than the upper surface of the through hole 32 by a distance corresponding to 1/3 of the thickness of the metal plate 20, so that the die 30 and the knockout 50 are flush with each other. It is possible to prevent the metal plate 20 from being pushed out around the material of the metal plate and to prevent the metal plate 20 from being broken at the edge of the through hole 32. In addition, according to the back extrusion method described in Patent Document 1, the inner diameter of the shaft changes stepwise. On the other hand, the punch 40 of the present embodiment uniformly processes the inner diameter of the shaft 10 in the length direction of the shaft 10. Therefore, stress concentration at the base of the shaft 10 can be prevented and the strength of the shaft 10 can be improved.

  The pressing means 60 is provided around the punch 40 and presses the metal plate 20 supported in a region other than the through hole 32 of the die 30 so as not to float from the die 30. Thereby, the shape of the metal plate 20 of parts other than the axis | shaft 10 can be accurately maintained in the state before axis | shaft 10 formation. In addition, the volume of the area | region located above the through-hole 32 among the metal plates 20 before the press work shown in FIG. 2 corresponds with the sum of the volume of the top | upper surface and side surface of the axis | shaft 10 shown in FIG.

  The die 30 is formed with a die side R34 by rounding the entire circumference of the edge of the through hole 32. The die side R34 of this embodiment is, for example, R0.2. Since the die side R <b> 34 is formed on the die 30, the metal plate 20 can be smoothly drawn into the die 30 by the punch 40. Moreover, the punch side dome 42 is formed by gently rising the tip of the punch 40 from the periphery toward the center. The curvature of the punch side dome 42 is, for example, R300. On the other hand, the knockout side depression 52 is formed by gently denting the tip of the knockout 50 from the periphery toward the center. The curvature of the knock-out recess 52 is R30, for example. Further, the punch 40 has a punch side angle R44 formed by rounding the entire periphery of the tip. The punch side angle R44 is, for example, R0.5. The metal plate 20 compressed by the punch 40 and the knockout 50 can be smoothly rolled toward the side surface of the shaft 10 by the effects of the punch side dome 42, the knockout side recess 52, and the punch side angle R <b> 44. Thereby, the back pressure of the knockout 50 necessary for forming the shaft 10 can be lowered, and the durability of the shaft forming device 100 can be improved.

  FIG. 5 shows the correlation between the diameter of the shaft 10 and the back pressure of the knockout 50. In the figure, the horizontal axis indicates the diameter of the shaft 10, and the vertical axis indicates the back pressure applied to the metal plate 20 by the knockout 50. Since the back pressure is controlled by the load applied to the knockout 50, the unit of the back pressure is the load [ton]. For example, the shaft 10 of the present embodiment has a diameter of 7.4 mm, and the back pressure of the knockout 50 is 6 [ton]. As shown in this figure, the back pressure of the knockout 50 is in a monotonically increasing relationship with the increase in the diameter of the shaft 10. For example, if the shaft diameter of the shaft 10 is x and the back pressure of the knockout 50 is y, the relationship of y = 10.14x is established between them.

  As is clear from the above description, according to the present embodiment, the shaft forming apparatus 100 that reduces the machining cost of the shaft 10 can be provided by forming the shaft 10 from the metal plate 20 in one step.

  Furthermore, according to other embodiment, the flange which can mount | wear with the securing member with respect to the member with which the shaft 10 was mounted | worn can be formed in the front-end | tip of the shaft 10 of the shaft product 99 formed as mentioned above. In the following description, members common to those in FIGS. 1 to 4 are denoted by common reference numerals, and redundant description is omitted.

  FIG. 6 is a view showing the shape of the punching die 210 used in the next step. As shown in the figure, the punching die 210 is a solid solid metal block 212 as a whole, and has a through-hole 214 penetrating from the top surface to the bottom surface at the center thereof. The horizontal cross-sectional shape of the through hole 214 is a cross shape.

  On the other hand, FIG. 7 is a perspective view showing the shape of a punching punch 220 used in combination with the punching die 210 shown in FIG. The punching punch 220 includes a square columnar pressing portion 222 and a punching portion 224 having a cross-sectional shape complementary to the through hole 214 of the punching die 210. Here, the horizontal cross-sectional shape of the punched portion 224 has substantially the same shape and size as the through-hole 214 as long as it can be inserted into the through-hole 214. Therefore, when the punched portion 224 is inserted into the through hole 214, there is a gap suitable for punching between the punched portion 224 and the through hole 214. Further, the edge portion 226 of the end face of the punched portion 224 is finished with a sharp corner.

  When the punching die 210 and the punching punch 220 as described above are attached to the molding apparatus, they are positioned relative to each other so that the punching portion 224 of the punching punch 220 penetrates smoothly into the through hole 214 of the punching die 210. . The shaft product 99 shown in FIG. 1 is set so that the top surface of the shaft 10 abuts on the surface of the punching die 210 mounted in this way. At this time, the shaft product 99 is positioned so that the center of the top surface of the shaft 10 coincides with the center of the through hole 214 of the punching die 210. Further, when the punching punch 220 is lowered in this state, a part of the top surface of the shaft 10 is cut out in the same shape as the cross section of the punching part 224 of the punching punch 220.

  FIG. 8 is a perspective view showing the shape of the shaft product 99 in which the notch 12 is formed by the punching process as described above. As shown in the figure, notches 12 are formed radially on the top surface of the shaft 10 in the radial direction from the center thereof. In other words, four sector-shaped (fan-shaped) segments 14 are cut out on the top surface.

  FIG. 9 is a perspective view showing the shape of the burring die 310 used in the next startup process. As shown in the drawing, the burring die 310 is formed of a cubic metal lump 312 and has a through hole 314 having a cylindrical inner surface at the center thereof. The inner diameter of the through hole 314 is substantially equal to the outer diameter of the sector-shaped section 14 formed at the tip of the shaft 10.

  FIG. 10 is a perspective view showing the shape of a burring punch 320 used in combination with the burring die 310 shown in FIG. As shown in the figure, the burring punch 320 includes a cylindrical straight barrel portion 322 having a constant diameter, and a bullet-shaped tip portion 324 formed at one end of the straight barrel portion 322. Here, the outer diameter of the straight body portion 322 is substantially equal to the inner diameter of the sector-shaped piece 14 formed at the tip of the shaft 10.

  FIG. 11 is a cross-sectional view showing a state in which the shaft product 99 is processed by the molding apparatus 110 equipped with the burring die 310 and the burring punch 320 as described above. As shown in the figure, the shaft 10 is set so that its top surface is in contact with the upper surface of the burring die 310. Further, the center of the top surface of the shaft 10 is set so that the center of the through hole 314 of the burring die 310 coincides. In this state, when the burring punch 320 is penetrated from the inside of the shaft 10 toward the inside of the through hole 314, each piece 14 formed on the top surface in the previous step is formed inside the through hole 314 inside the shaft 10. It can be bent in the height direction.

  FIG. 12 is a perspective view showing the shape of the shaft product 99 processed as described above. As shown in the figure, each of the sector-shaped pieces 14 formed on the top surface of the shaft 10 rises in the height direction of the shaft 10 from the top surface. However, as can be seen from FIG. 11, a shoulder portion 16 is formed in the peripheral portion of the top surface by leaving a region having a certain width without being deformed.

  FIG. 13 is a perspective view showing the shape of the pre-bending die 410 used in the next step for the shaft product 99. As shown in the figure, the preliminary bending die 410 is formed by a pair of divided dies 411 and 412 each having a semicircular machining surface 418. When these divided dies 411 and 412 are joined while facing each other at the side end surface having the processing surface 418, a bending surface 418 inclined at 45 ° with respect to the upper surface and a small angle formed perpendicular to the upper surface are formed. A circular processed portion including the support surface 416 is formed. The inner diameter of the processed portion is substantially equal to the outer diameter of the plurality of pieces 14 rising on the top surface of the shaft product 99 shown in FIG. A large support surface 414 having a shape complementary to the side surface of the shaft 10 of the shaft product 99 is formed below the processed surface 418.

  FIG. 14 is a perspective view showing the shape of the preliminary bending punch 420 used in combination with the preliminary bending die 410. As shown in the figure, the pre-bending punch 420 has a circular horizontal sectional shape as a whole, and has a cylindrical straight body portion 422 and an intrusion portion 424 having a smaller diameter than the straight body portion 422 formed at the tip thereof. And. On the end surface of the straight body portion 422 where the penetration portion 424 is formed, a step corresponding to the difference in diameter between the two is formed. This step is inclined by 45 ° with respect to the side surface of the straight body portion 422, and forms a processed surface 423 that contributes to bending processing described later. On the other hand, an inclined surface is also formed at the peripheral edge of the distal end of the penetration portion 424, which is a chamfered portion 425 formed so that the penetration portion 424 smoothly penetrates into the shaft 10. The penetration portion 424 has an outer diameter that can penetrate the inside of the section 14 rising from the top surface of the shaft product 99.

  FIG. 15 shows the shape of the pre-bending receiver 430 for preventing unnecessary deformation of the shaft 10 when the pre-bending process is performed using the pre-bending die 410 and the pre-bending punch 420 shown in FIGS. FIG. As shown in the figure, the preliminary bending receiver 430 includes a cylindrical straight body 434 protruding from a cubic metal lump 432. Further, the front end surface 438 of the straight body portion 434 is horizontal, and a recessed portion 439 having an inner diameter complementary to the outer diameter of the penetration portion 424 of the preliminary bending punch 420 shown in FIG. Further, a chamfered portion 436 is formed at the peripheral edge of the upper end of the straight body portion 434 so as to be smoothly inserted into the shaft 10 as will be described later. Therefore, only the annular region sandwiched between the chamfered portion 436 and the recessed portion 439 forms a horizontal plane on the front end surface 438 of the straight body portion 434.

  FIG. 16 is a cross-sectional view for explaining the operation of the molding apparatus 120 equipped with the preliminary bending die 410, the preliminary bending punch 420, and the preliminary bending receiver 430 shown in FIGS. As shown in the figure, the shaft product 99 is set in the molding apparatus 120 with the shaft 10 facing downward and the preliminary bending receiver 430 inserted therein. At this time, the straight body portion 434 of the preliminary bending receiver 430 is substantially in close contact with the inner surface of the shaft 10. Further, the front end surface 438 of the straight body portion 434 is in contact with the back surface of the shoulder portion 16 of the shaft 10. Further, the metal plate 20 portion of the shaft product 99 is also in close contact with the surface of the metal block 432 of the preliminary bending receiver 430. Therefore, the shaft product 99 will not be deformed toward the inside even when subjected to a pre-bending process as will be described later.

  Further, in the molding apparatus 120, the divided dies 411 and 412 that form the preliminary bending die 410 are disposed on the side of the shaft 10 so as to face each other. Further, the pre-bending punch 420 is disposed to face the pre-bending receiver 430 from below the shaft 10. At this time, the recessed portion 439 of the preliminary bending receiver 430 and the penetration portion 424 of the preliminary bending punch 420 are arranged on the same axis.

  FIG. 17 shows a state in which the pair of split dies 411 and 412 are brought close to each other and brought into contact with the shaft 10 and the split dies 411 and 412 are also brought into contact with each other in the molding apparatus 120 shown in FIG. . At this time, the large support surfaces 414 of the divided dies 411 and 412 are in close contact with the side surfaces of the shaft 10. The small support surfaces 416 of the split dies 411 and 412 are in close contact with the vicinity of the root of the section 14 of the shaft 10. However, at this stage, the shaft product 99 has not undergone substantial deformation and has not yet been subjected to preliminary bending.

  FIG. 18 is a cross-sectional view showing a state in which the pre-bending process is performed by raising the pre-bending punch 420 in the molding apparatus 120 shown in FIGS. 16 and 17. As shown in the figure, in the section 14 of the shaft 10, the vicinity of the base is sandwiched between the small support surface 416 of the pre-bending die 410 and the side surface of the penetration portion 424 of the pre-bending punch 420, and the top surface of the shaft 10. And held upright. On the other hand, the vicinity of the tip of the section 14 is pressed against the processing surface 418 of the preliminary bending die 410 by the processing surface 423 of the preliminary bending punch 420 until an angle of 45 ° is formed with respect to the top surface of the shaft 10. It is bent toward the outside of the shaft 10. As already described, the portion other than the vicinity of the tip of the section 14 of the shaft product 99 is sandwiched between the preliminary bending receiver 430 and the preliminary bending die 410. Therefore, even if an external force is applied by the preliminary bending process, the portion other than the tip of the section 14 is not deformed at all.

  FIG. 19 is a perspective view showing the outer shape of the shaft product 99 formed by the pre-bending process as described above. As shown in the figure, each of the sections 14 stands upright in the height direction of the shaft 10 at the wide portion 15 near the base to the shaft 10. On the other hand, the distal end portion 17 of the section 14 is expanded in a direction away from the center of the shaft 10.

  FIG. 20 is a perspective view showing the shape of the finish bending die 510 used in the next step for the shaft product 99. As shown in the figure, the finish bending die 510 is formed by a pair of split dies 511 and 512 each having a semi-supporting small support surface 516. When these divided dies 511 and 512 are coupled with the side end surfaces having the small support surfaces 516 facing each other, a partial region of the upper surface adjacent to the small support surfaces 516 becomes the bending surface 518. The inner diameter of the small support surface 516 is substantially equal to the outer diameter of the plurality of pieces 14 rising on the top surface of the shaft product 99 shown in FIG. A large support surface 514 having a shape complementary to the side surface of the shaft 10 of the shaft product 99 is formed below the small support surface 516.

  FIG. 21 is a perspective view showing the shape of the finish bending punch 520 used in combination with the finish bending die 510. As shown in the figure, the finish bending punch 520 has a circular horizontal cross-sectional shape as a whole, a cylindrical straight body portion 522, and an intrusion portion 524 having a smaller diameter than the straight body portion 522 formed at the tip thereof. And. On the end surface of the straight body portion 522 on the side where the penetrating portion 524 is formed, a step corresponding to the difference in diameter between the two is formed. This level | step difference has comprised the process surface 523 which contributes to the bending process mentioned later. On the other hand, an inclined surface is also formed at the peripheral edge of the distal end of the penetration portion 524, which is a chamfered portion 525 formed so that the penetration portion 524 smoothly penetrates into the shaft 10. In addition, the penetration portion 524 has an outer diameter that can penetrate the inside of the section 14 rising from the top surface of the shaft product 99.

  FIG. 22 shows the shape of the tip bending receiver 530 for preventing unnecessary deformation of the shaft 10 when finishing bending is performed using the finishing bending die 510 and the finishing bending punch 520 shown in FIGS. FIG. As shown in the figure, the finish bending receiver 530 includes a cylindrical straight body portion 534 protruding from a cubic metal lump 532. Further, the front end surface 538 of the straight body portion 534 is horizontal, and a recessed portion 539 having an inner diameter complementary to the outer diameter of the penetration portion 524 of the finish bending punch 520 shown in FIG. Further, a chamfered portion 536 is formed on the peripheral edge of the upper end of the straight body portion 534 so that it can be smoothly inserted inside the shaft 10 in finish bending described later. Therefore, only the annular region sandwiched between the chamfered portion 536 and the depressed portion 539 forms a horizontal plane on the front end surface 538 of the straight body portion 534.

  FIG. 23 is a cross-sectional view for explaining the operation of the molding apparatus 130 equipped with the finish bending die 510, the finish bending punch 520, and the finish bending receiver 530 shown in FIGS. As shown in the figure, the shaft product 99 is set in the molding apparatus 130 with the shaft 10 facing downward and the finish bending receiver 530 inserted therein. At this time, the straight body portion 534 of the finish bending receiver 530 is in close contact with the inner surface of the shaft 10. Further, the front end surface 538 of the straight body portion 534 is in contact with the back surface of the shoulder portion 16 of the shaft 10. Further, the metal plate 20 portion of the shaft product 99 is also in close contact with the surface of the metal block 532 of the finish bending receiver 530. Therefore, the shaft product 99 will not be deformed toward the inner side even if it is subjected to finish bending as described later.

  In the molding apparatus 130, the split dies 511 and 512 that form the finish bending die 510 are disposed on the side of the shaft 10 so as to face each other. Further, the finish bending punch 520 is disposed to face the finish bending receiver 530 from below the shaft 10. At this time, the depressed portion 539 of the finish bending receiver 530 and the penetration portion 524 of the finish bending punch 520 are arranged on the same axis.

  FIG. 24 shows a state where the pair of split dies 511 and 512 are brought close to each other and brought into contact with the shaft 10 at the same time as the split dies 511 and 512 themselves are brought into contact with each other in the molding apparatus 130 shown in FIG. Show. At this time, the large support surfaces 514 of the split dies 511 and 512 are substantially in close contact with the side surface of the shaft 10. Further, the small support surfaces 516 of the split dies 511 and 512 are in close contact with the vicinity of the root of the section 14 of the shaft 10. However, at this stage, no substantial deformation has occurred in the shaft product 99, and the finish bending process has not yet been performed.

  FIG. 25 is a cross-sectional view showing a state where the finish bending punch 520 is raised and the finish bending process is performed in the molding apparatus 130 shown in FIGS. 23 and 24. As shown in the figure, in the section 14 of the shaft 10, the vicinity of the root is sandwiched between the small support surface 516 of the finish bending die 510 and the side surface of the penetration portion 524 of the finish bending punch 520, and the top surface of the shaft 10. And held upright. On the other hand, the vicinity of the tip of the section 14 is pressed against the processing surface 518 of the finishing bending die 510 by the processing surface 523 of the finishing bending punch 520 and forms an angle of 90 ° with respect to the top surface of the shaft 10. It is bent toward the outside of the shaft 10. As already described, the portion other than the vicinity of the tip of the section 14 of the shaft product 99 is sandwiched between the finish bending receiver 530 and the finish bending die 510. Therefore, even if an external force is applied by the above finish bending process, the portions other than the tip of the section 14 are not deformed at all.

  FIG. 26 is a perspective view showing the outer shape of the shaft product 99 formed by the finish bending process as described above. As shown in the figure, each of the sections 14 stands upright in the height direction of the shaft 10 at the wide portion 15 near the base to the shaft 10. On the other hand, the distal end portion 17 of the section 14 is expanded in a direction away from the center of the shaft 10, and is expanded until it becomes parallel to the top surface to form a flange. Therefore, the tip end portion 17 is obtained by bending the section 14 (FIG. 12) raised in the start-up process by 90 °.

  In the shaft product 99 created as described above, the tip of the section 14 remains in the region within the diameter of the shaft 10. Therefore, a part having a shaft hole having a shape complementary to the shaft 10, for example, a gear, a cam, a lever, or the like can be inserted into the shaft 10. In addition, by mounting a component having the same thickness as the shaft 10 and then mounting a fastener such as a C clip or E clip on the wide portion 15 of the section 14, the component mounted on the shaft 10 can be prevented from falling off. Further, by setting the distance between the tip 17 of the section 14 and the shoulder 16 of the shaft 10 to be the same as the thickness of these fasteners, the component mounted on the shaft 10 can be rotated without backlash of the shaft. The C clip or E clip is formed of an elastic material such as resin or metal, has the same inner diameter as the wide portion 15, has an outer diameter larger than the outer diameter of the shaft 10, and is partially cut. An annular part. Moreover, since it can push in from the side with respect to the wide part 15 and it can mount | wear easily, components can be attached to the axis | shaft 10 by easy operation | work.

  In the above embodiment, the bending process of the slice 14 is performed by dividing it into a preliminary bending process and a finishing bending process. However, if the workability and thickness of the material are sufficiently large, the preliminary bending process is omitted. The flange can be formed by a single bending process.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

It is a perspective view of the axis | shaft 10 formed in this embodiment. 3 is a cross-sectional view of the shaft 10. FIG. 1 is a sectional view of a shaft forming device 100. FIG. 3 is a cross-sectional view showing a state where the shaft forming device 100 forms the shaft 10. FIG. It is a graph which shows the correlation with the diameter of the axis | shaft 10, and the back pressure of the knockout 50. FIG. It is a perspective view which shows the shape of the punching die 210 used in a punching process. It is a perspective view which shows the shape of the punching punch 220 used in a punching process. It is a perspective view which shows the shape of the shaft product 99 punched in the punching process. It is a perspective view which shows the shape of the burring die 310 used in a starting process. It is a perspective view which shows the shape of the burring punch 320 used in a starting process. It is a perspective view which shows the shape of the axis | shaft product 99 lifted and processed in the starting process. It is a perspective view which shows the shape of the axis | shaft product 99 lifted and processed in the starting process. It is a perspective view which shows the shape of the prebending die 410 used in a prebending process. It is a perspective view which shows the shape of the pre-bending punch 420 used in a pre-bending process. It is a perspective view which shows the shape of the preliminary | backup bending receiver 430 used in a preliminary | backup bending process. It is sectional drawing which shows the layout of the shaping | molding apparatus 120 which implements a pre-bending process. It is sectional drawing which shows the intermediate | middle operation | movement of the shaping | molding apparatus 120 which implements a pre-bending process. It is sectional drawing which shows the last operation | movement of the shaping | molding apparatus 120 which implements a pre-bending process. It is a perspective view which shows the shape of the shaft product 99 which carried out the pre-bending process in the pre-bending process. It is a perspective view which shows the shape of the finish bending die 510 used in a finish bending process. It is a perspective view which shows the shape of the finish bending punch 520 used in a finish bending process. It is a perspective view which shows the shape of the finish bending receiver 530 used in a finish bending process. It is sectional drawing which shows the layout of the shaping | molding apparatus 130 which implements a finishing bending process. It is sectional drawing which shows the intermediate | middle operation | movement of the shaping | molding apparatus 130 which implements a finishing bending process. It is sectional drawing which shows the last operation | movement of the shaping | molding apparatus 130 which implements a finishing bending process. It is a perspective view which shows the shape of the shaft product 99 finished-bending in the final bending process.

Explanation of symbols

10 shafts, 12 notches, 14 sections, 15 wide parts, 16 shoulders, 17 tips, 20 metal plates, 30 dies, 32, 214, 314 through holes, 34 dies side R, 40 punches, 42 punch side dome , 44 Punch side angle R, 50 Knockout, 52 Knockout side depression, 60 Pressing means, 99 axis product, 100 axis forming device, 110, 120, 130 Molding device, 210 Punching die, 212, 312, 432, 532 Metal lump, 220 punching punch, 222 pressing part, 224 punching part, 226 edge part, 310 burring die, 320 burring punch, 322, 422, 434, 522, 534 straight body part, 324 tip part, 410 preliminary bending die, 411, 412, 511, 512 Split die, 414, 514 Large support surface, 416, 5 16 Small support surface, 418, 423, 518, 523 Machining surface, 420 Pre-bending punch, 424, 524 Penetration part, 425, 436, 517, 525, 536 Chamfering part, 430 Pre-bending receiver, 438, 538 Tip surface, 439 539 Depression, 510 Finish bending die, 520 Finish bending punch, 530 Finish bending receiver

Claims (14)

A shaft forming device that forms a hollow shaft protruding from the metal plate by pressing the metal plate,
A through hole having the same inner diameter as the outer shape of the shaft is formed, and a die that supports the metal plate to be processed on the upper surface of the through hole;
A punch that has the same outer shape as the inner diameter of the shaft and pushes the metal plate supported on the upper surface of the through hole into the through hole;
Provided inside the through-hole of the die, and when the punch pushes the metal plate into the through-hole, while moving to the back of the through-hole while facing the tip of the punch, A shaft forming apparatus comprising: a knockout that rolls the metal plate pushed by the tip of the punch onto the side surface of the shaft by applying back pressure. The shaft forming apparatus according to claim 1, further comprising a pressing unit that is provided around the punch and that holds the metal plate supported in a region other than the through hole of the die so as not to float from the die.   The shaft forming apparatus according to claim 1, wherein the die is rounded on the entire circumference of the edge of the through hole.   The shaft forming apparatus according to claim 1, wherein a tip end of the punch gently rises from the periphery toward the center, and a tip end of the knockout is gently depressed from the periphery toward the center.   In a state where the die supports the metal plate on the upper surface of the through hole, the knockout waits at a position lower than the upper surface of the through hole by a distance corresponding to 1/3 of the plate thickness of the metal plate. The shaft forming device according to claim 1.   The shaft forming apparatus according to claim 1, wherein the punch uniformly processes an inner diameter and an outer diameter of the shaft in a length direction of the shaft. A shaft forming method for forming a hollow shaft protruding from the metal plate by pressing the metal plate,
A preparatory step of placing the metal plate to be processed on the upper surface of the through hole of a die in which a through hole having the same inner diameter as the outer shape of the shaft is formed;
While pushing the metal plate supported on the upper surface of the through hole with a punch having the same outer shape as the inner diameter of the shaft, the knockout provided in advance in the through hole of the die is A punching and forging step of rolling the metal plate pushed by the tip of the punch onto the side surface of the shaft by applying back pressure to the metal plate with the knockout in a state of being opposed to the tip of the punch. A shaft forming method provided.   The shaft forming method according to claim 7, wherein in the preparation step, the knockout is made to stand by at a position lower than the upper surface of the through hole by a distance corresponding to の of the plate thickness of the metal plate. A punching process using a punch and a die to form three or more linear cuts formed radially from the center of the top surface of the shaft;
Using a burring punch and a burring die to push and bend a plurality of sector-shaped sections defined by the incisions, and to stand up the sections in the height direction of the shaft;
Using a bending punch and a bending die, the tip of the section that stands upright in the axial direction is bent radially with respect to the axis, and the section stands upright with respect to the top surface, and the tip of the upright section The shaft forming method according to claim 7, further comprising a bending step of forming a horizontal portion extending radially from the horizontal portion.   The shaft forming method according to claim 9, wherein a tip portion of the horizontal portion is positioned inside a region defined by extending a side surface of the shaft in the axial direction.   10. The bending process according to claim 9, further comprising: an intermediate bending process of bending the tip of the upright part to an intermediate angle of less than 90 °; and a final bending process of bending the tip to 90 ° to form a horizontal part. Shaft forming method.   The shaft forming method according to claim 9, wherein in the bending step, a part of the bending die is in contact with the upright portion from the side to prevent deformation.   The shaft forming method according to claim 9, wherein in the bending step, a bending receiver is brought into contact with the back surface of the top surface from the inside of the shaft to prevent deformation of the top surface.   The shaft forming method according to claim 9, wherein a distance between the horizontal portion and the top surface is substantially equal to a thickness of a C-ring attached to the upright portion.

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