An extrusion die without draft angle

Abstract

The present application relates to an extrusion die without a draft angle, belonging to the technical field of forging dies, including an upper die, a lower die and a side die arranged on a workbench, the upper die and the side die are slidably arranged on the workbench, an extrusion block and an inner die core are coaxially arranged on one side of the upper die facing the lower die, the inner die core includes a tie rod and a multi-petal support die, the multi-petal support die is slidably connected to the tie rod, a gap is arranged between adjacent support dies, a clearance cavity is arranged on one side of the support die close to the tie rod axis, when the inner die core is fitted with the lower die, the inner die core is in an outward state, at which time the extrusion block is embedded between the inner die core and the side die, the inner die core can cooperate with the extrusion block, the side die and the lower die to form a cavity, when the inner die core is separated from the lower die, the inner die core is in a contracted state, the tie rod is provided with a control part for controlling the contraction and outward release of the support die, and the lower die is provided with a centering mechanism for providing positioning for the centering placement of the blank. The present application has the effect of extending the service life of the die for forming hollow shaft forgings.

Description

Technical Field

[0001] The present application relates to the technical field of forging dies, and in particular to an extrusion die without a draft angle. Background Art

[0002] The steel industry has strongly supported and driven the development of related industries and promoted social employment. Hollow shaft forgings are one of the most common parts in the machinery industry and are widely used in automobiles, motorcycles, energy mining and other fields.

[0003] During the forming process of hollow shaft forgings, a certain draft angle is usually designed on the edge of the workpiece to facilitate the separation of the workpiece from the die. However, this design will increase the friction during the forging process, causing the inner die core to be subjected to greater axial and radial pressure, thus affecting the service life of the inner die core. Summary of the invention

[0004] In order to extend the service life of a die used for forming hollow shaft forgings, the present application provides an extrusion die without a draft angle.

[0005] The present application provides an extrusion die without a draft angle, which adopts the following technical solution:

[0006] An extrusion die without a draft angle, characterized in that it comprises an upper die, a lower die and a side die arranged on a workbench, the upper die and the side die are slidably arranged on the workbench, an extrusion block and an inner die core are coaxially arranged on one side of the upper die facing the lower die, the side die comprises a left die and a right die symmetrically arranged on both sides of the lower die, the inner die core comprises a tie rod and a multi-petal support die, the tie rod is arranged on the upper die, the multi-petal support die is slidably connected to the tie rod, a gap is arranged between adjacent support dies, a clearance cavity is arranged on one side of the support die close to the axis of the tie rod, the clearance cavity cooperates with the gap to provide clearance for the contraction of the inner die core;

[0007] When the inner mold core is in fit with the lower mold, the inner mold core is in an outward state. At this time, the extrusion block is embedded between the inner mold core and the side mold. The inner mold core can cooperate with the extrusion block, the side mold and the lower mold to form a cavity. When the inner mold core is separated from the lower mold, the inner mold core is in a retracted state. The pull rod is provided with a control part for controlling the retraction and outward release of the support mold. The lower mold is provided with a centering mechanism for providing positioning for the centering placement of the blank.

[0008] By adopting the above technical scheme, the inner die core follows the sliding, outward expansion and contraction of the upper die, and flexibly matches the forging state and the blanking state of the die. By setting the contraction of the inner die core, the friction between the die and the forging can be reduced during the demolding process without setting the draft angle, which not only facilitates the demolding of the forging, but also can extend the service life of the die for hollow shaft forgings to a certain extent. By setting the centering mechanism, it is not easy for the blank to touch and generate friction during the sliding of the inner die core to fit with the lower die, thereby reducing the wear of the inner die core and extending the service life of the die for hollow shaft forgings.

[0009] Preferably, the control member comprises a control block arranged on the pull rod, and the control block can be driven to slide by the pull rod when the upper die slides, and a control cavity for sliding the control block is arranged on the support die, and a control part is arranged on the end surface of the control block facing the upper die, and the control part is arranged at an angle close to the end surface of the pull rod, and a control inclined groove cooperating with the control part is opened on the support die, and the control cavity is connected with the control inclined groove, so that the control cavity is a forging area, a positioning area and a retracting area in sequence along the direction toward the upper die;

[0010] When the control block is located in the retracted area, the inner mold core is in a retracted state under the cooperation of the inclined surface of the control part and the control inclined groove, and the inner mold core is separated from the lower mold. When the control block is located in the positioning area, the inner mold core is fitted with the lower mold, and the inner mold core is in an outward state. When the control block is located in the forging area, the extrusion block is embedded between the inner mold core and the side mold.

[0011] By adopting the above technical scheme, under the cooperation of the control block, the control part and the control bevel groove, the extension and retraction of the inner die core can be controlled by the sliding of the upper die, and in the process of blanking the forging, when the inner die core is separated from the lower die under the action of the upper die, the inner die core can be retracted under the action of the control part and the control bevel groove, so that the inner die core is separated from the forging, reducing the friction with the forging during the separation process of the inner die core and the forging, on the one hand extending the service life of the mold for forming hollow shaft forgings, on the other hand ensuring the quality of the forgings.

[0012] Preferably, the lower mold is provided with a positioning boss for positioning the inner mold core. The positioning boss is arranged in a truncated cone shape, and the diameter of the positioning boss increases successively in the direction toward the lower mold. The supporting mold is provided with a positioning inclined surface that cooperates with the side wall of the positioning boss. When the supporting mold is in affixed with the lower mold, the giving way inclined surface is in affixed with the side wall of the positioning boss.

[0013] By adopting the above technical solution, with the cooperation of the positioning boss and the give-way slope, a guide positioning is provided for the outward release of the support mold, so that the inner mold core can slide to the position where it cooperates with the side mold, the lower mold and the extrusion block to form a cavity.

[0014] Preferably, a placement boss is provided on the lower mold, and when the inner mold core slides to fit with the placement boss, the outer diameter of the placement boss is consistent with the outer diameter of the inner mold core.

[0015] By adopting the above technical solution, the placement boss can provide positioning for the position of the blank when it is placed. When the placement boss is located on the inner ring of the blank, during the process of the inner mold core sliding to fit with the placement boss, the inner mold core is not easy to touch the inner ring of the blank, thereby reducing the friction between the inner mold core and the blank, thereby extending the service life of the mold for forming hollow shaft forgings.

[0016] Preferably, the centering mechanism includes a plurality of centering sliders slidably arranged on the lower mold, and the plurality of centering sliders are arranged in a circular array with the axis of the lower mold as the center. The lower mold is provided with a centering groove for the sliding movement of the centering slider, and the centering groove passes through the placement boss. When the upper mold slides until the inner mold core and the lower mold are in fit, the connection between the centering groove and the outside is closed. The centering slider is provided with a centering inclined surface on the side facing the side mold, and the centering inclined surface provides a guide for the centering placement of the blank. The lower mold is provided with a centering elastic member for pushing the centering slider to slide toward the outside of the centering groove.

[0017] By adopting the above technical scheme, since the opening of the centering slide groove is located on the placing boss, when the upper mold slides to the inner mold core and fits with the placing boss, the inner mold core can close the connection between the centering slide groove and the outside world, and the setting of the centering slider and the centering slide groove is not easy to affect the normal use of the mold; the centering bevel provides a guide for the centering placement of the billet, and during the placement of the billet, the billet can slide under the action of the centering bevel to fit with the side wall of the centering slider, and in the process of the inner mold core sliding to fit with the lower mold, it is further made difficult for the inner mold core to contact the billet, thereby extending the service life of the mold for forming hollow shaft forgings; through the setting of the centering elastic part, when the inner mold core slides to release the closure of the centering slide groove, the centering slider can be restored under the action of the centering elastic part.

[0018] Preferably, the side mold includes a base plate that is fitted with the workbench, and an interlocking cavity for the base plate to be interlocked is reserved between the lower mold and the workbench, the centering groove passes through the lower mold, and a locking groove is provided on the base plate. When the side mold slides to fit with the lower mold, the base plate is embedded in the interlocking cavity and the centering groove is connected to the locking groove. When the centering slider is received in the centering groove under the action of the inner mold core, the end of the centering slider away from the upper mold slides to be embedded in the locking groove.

[0019] By adopting the above technical solution, the centering slider cooperates with the locking slide groove to limit the slight movement of the side mold relative to the lower mold during the extrusion process of the extrusion block on the billet, which ensures the quality of the forged piece to a certain extent. A centering arc surface is provided on the side of the centering slider away from the centering inclined surface. The centering arc surface is provided to facilitate the centering slider to slide into the locking slide groove. The locking of the side mold does not require the addition of other components and control parts, which is convenient for operation and saves costs.

[0020] Preferably, a positioning ball is slidably connected to the centering slider, and the positioning ball slides radially along the lower mold. The centering slider is provided with a positioning groove for the positioning ball to slide, and the opening of the positioning groove is set toward the side mold. The positioning ball is rotatably set in the positioning groove. The centering slider is provided with a positioning elastic part for pushing the positioning ball to slide toward the side mold. When the inner mold core is in a retracted state, the positioning groove is located outside the centering groove, and the end face of the positioning ball facing away from the positioning boss is located on the side of the placement boss away from the positioning boss in the vertical direction.

[0021] By adopting the above technical scheme, during the placement process of the billet, the positioning ball is set to push the billet to move to the placement boss located on the inner circle of the billet, and further makes it difficult for the inner die core to contact the billet during the sliding of the inner die core to fit with the lower die, thereby extending the service life of the mold for forming hollow shaft forgings. During the separation of the forging from the lower die, the design of the positioning ball and the rotation of the positioning ball reduces the friction between the forging and the centering slider, making it difficult for the centering slider to scratch the forging, thereby ensuring the quality of the forging.

[0022] Preferably, a guide ball is rotatably connected to the centering slider, and a guide groove for the guide ball to slide is provided on the bottom wall of the support mold. A locking groove for the guide ball to be engaged is also provided on the bottom wall of the support mold. The guide groove is connected to the locking groove, and the locking groove is located on the side of the guide groove close to the axis of the pull rod, and the opening of the guide groove increases sequentially in the direction away from the locking groove.

[0023] By adopting the above technical scheme, when the inner mold core slides to fit with the placement boss, the guide ball is embedded in the locking groove. Through the provision of the guide ball, on the one hand, the friction between the inner mold core and the centering slider is reduced, thereby reducing the wear of the centering slider on the inner mold core. On the other hand, the guide ball can cooperate with the guide groove and the locking groove to provide positioning for the inner mold core when the inner mold core is placed outward, further ensuring the gap between adjacent inner mold cores when the inner mold core fits with the placement boss; the opening of the guide groove is arranged to increase in sequence in the direction away from the locking groove, so that the guide ball can slide along the guide groove to be embedded in the locking groove.

[0024] Preferably, two adjacent centering sliding blocks are connected via a connecting block, and a connecting groove for sliding movement of the connecting block is provided on the lower mold, and the connecting groove is connected to the centering groove.

[0025] By adopting the above technical solution, through the setting of the connecting block and the connecting groove, on the one hand, the sliding length of the centering slider is limited, so that the centering slider is not easy to slide and separate from the lower mold. On the other hand, the centering slider can slide synchronously, thereby improving the linkage of the centering mechanism.

[0026] Preferably, the upper mold is provided with a rib and a positioning column, the rib is coaxially arranged with the upper mold, the inner diameter of the rib is consistent with the outer diameter of the side mold, and the side mold is provided with a positioning through hole cooperating with the positioning column.

[0027] By adopting the above technical scheme, the end of the side die facing away from the workbench is limited by the setting of the retaining edge, and the side die is further restricted from slight movement relative to the lower die during the extrusion process of the billet by the extrusion block, thereby ensuring the quality of the forgings; the positioning column cooperates with the positioning through hole to position the position between the upper die and the side die, so as to facilitate the upper die to slide to the outer wall of the side die and fit with the inner wall of the baffle, and to facilitate the extrusion block to be embedded between the inner die core and the side die, thereby effectively reducing the wear of the inner die core and the side die caused by the extrusion block.

[0028] In summary, the present application includes at least one of the following beneficial technical effects:

[0029] 1. The inner die core follows the sliding, expansion and contraction of the upper die, flexibly matching the forging state and blanking state of the die. By setting the contraction of the inner die core and the sliding of the side die, the friction between the die and the forging can be reduced during the demoulding process without setting the draft angle, which not only facilitates the demoulding of the forging, but also prolongs the service life of the die for hollow shaft forgings to a certain extent;

[0030] 2. The placement boss can provide positioning for the blank when it is placed. When the placement boss is located on the inner ring of the blank, the inner mold core is not easy to touch the inner ring of the blank during the process of the inner mold core sliding to fit with the placement boss, thereby reducing the friction between the inner mold core and the blank, thereby extending the service life of the mold for forming hollow shaft forgings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a cross-sectional view of the overall structure when the control block in the embodiment of the present application is located in the positioning area.

[0032] Figure 2 It is a schematic diagram of the bottom surface structure of the support mold when the inner core mold of the embodiment of the present application is in an outward state.

[0033] Figure 3 yes Figure 1 Enlarged view of part A in .

[0034] Figure 4 It is a cross-sectional view of the overall structure when the control block in the embodiment of the present application is located in the retracted area.

[0035] Figure 5 yes Figure 4 Enlarged view of part B in .

[0036] Figure 6 This is a cross-sectional view from another perspective when the control block is located in the forging area in the embodiment of the present application.

[0037] Description of reference numerals: 1. workbench; 2. upper die; 21. extrusion block; 22. retaining edge; 23. positioning column; 3. lower die; 31. positioning boss; 32. placement boss; 33. fitting cavity; 4. side die; 41. left die; 42. right die; 43. bottom plate; 431. locking slide groove; 44. positioning through hole; 5. inner die core; 51. pull rod; 511. control block; 512. control part; 52. support die; 521. giving way cavity; 522. control chute; 523, positioning bevel; 524, guide groove; 525, locking groove; 53, gap; 54, control cavity; 541, forging area; 542, positioning area; 543, retracted area; 6, cavity; 7, centering slider; 71, centering groove; 72, centering bevel; 73, positioning ball; 731, positioning groove; 732, positioning spring; 74, guide ball; 75, connecting block; 751, connecting groove; 752, centering spring; 76, centering arc surface. DETAILED DESCRIPTION

[0038] The following is combined with Figure 1-6 This application is described in further detail.

[0039] The present application embodiment discloses an extrusion die without a draft angle, referring to Figure 1 , including an upper die 2, a lower die 3 and a side die 4 arranged on a workbench 1, the upper die 2 slides in the vertical direction, the side die 4 includes a left die 41 and a right die 42 symmetrically arranged on both sides of the lower die 3, and a first oil cylinder for controlling the sliding of the upper die 2 and two second oil cylinders for controlling the sliding of the side die 4 are fixed on the workbench 1. In the actual application process, a bracket for fixing the first oil cylinder and the second oil cylinder is fixed on the workbench 1, the piston rod of the first oil cylinder is coaxially fixed to the upper die 2 by bolts, and the piston rod of the third oil cylinder is fixed to the side die 4, and the sliding of the upper die 2 and the side die 4 is controlled by the oil cylinder, thereby improving the sliding stability.

[0040] Reference Figure 1 and Figure 2The upper mold 2 is coaxially provided with an extrusion block 21 and an inner mold core 5 on one side facing the lower mold 3. The inner mold core 5 is composed of a tie rod 51 and a multi-petal support mold 52. The tie rod 51 is coaxially fixed to the upper mold 2. The multi-petal support mold 52 is arranged in a circular array with the axis of the tie rod 51 as the center. The multi-petal support mold 52 is slidably connected to the tie rod 51. In the embodiment of the present application, the support mold 52 has six petals, and a 2 mm gap 53 is reserved between two adjacent support molds 52. A clearance cavity 521 is provided on the side of the support mold 52 close to the axis of the tie rod 51. The clearance cavity 521 cooperates with the gap 53 to provide clearance for the contraction of the inner mold core 5. When the inner mold core 5 is attached to the lower mold 3 When the upper mold 2 is closed, the inner mold core 5 is in an outward state. At this time, the extrusion block 21 is embedded between the inner mold core 5 and the side mold 4. The inner mold core 5 can cooperate with the extrusion block 21, the side mold 4 and the lower mold 3 to form a cavity 6. When the inner mold core 5 is separated from the lower mold 3, the inner mold core 5 is in a contracted state. The inner mold core 5 follows the sliding outward and contraction of the upper mold 2, and flexibly matches the forging state and the blanking state of the mold. Through the setting of the contraction of the inner mold core 5, the friction between the mold and the forging during the demolding process can be reduced without setting the draft angle, which not only facilitates the demolding of the forging, but also can extend the service life of the mold for forming hollow shaft forgings to a certain extent.

[0041] Reference Figure 1 and Figure 4 The pull rod 51 is provided with a control member for controlling the contraction and extension of the support die 52, and the control member includes a control block 511 coaxially fixed on the pull rod 51. When the upper die 2 slides, the control block 511 can be driven to slide through the pull rod 51. The support die 52 is provided with a control cavity 54 for controlling the sliding of the control block 511. A ring-shaped control portion 512 is integrally formed on the end surface of the control block 511 facing the upper die 2. The control portion 512 is inclined near the end surface of the pull rod 51. A control bevel 522 cooperating with the control portion 512 is provided on the support die 52. The control cavity 54 is connected to the control bevel 522 so that the control cavity 54 is sequentially divided into a forging area 541, a positioning area 542 and a retracting area 543 along the direction toward the upper die 2.

[0042] In the actual forging process, the annular blank must first be placed on the lower die 3 in the center, and then the side die 4 is controlled by the second oil cylinder to slide to fit with the lower die 3, and then the sliding of the upper die 2 is controlled by the first oil cylinder. Before the upper die 2 slides to the inner die core 5 and fits with the lower die 3, the control block 511 is located in the retracted area 543. At this time, the inner die core 5 is in a retracted state under the cooperation of the inclined surface of the control part 512 and the control inclined groove 522; when the upper die 2 slides to the inner die core 5 and fits with the lower die When the upper mold 2 is fitted and the control block 511 is located in the positioning area 542, the inner mold core 5 is in an outward state, and the blank is located between the side mold 4 and the inner mold core 5. This process is to perform preliminary positioning of the inner mold core 5. Then, as the upper mold 2 continues to slide, in the process of the control block 511 sliding from the positioning area 542 to the forging area 541, the extrusion block 21 is embedded between the inner mold core 5 and the side mold 4 to extrude the blank. When the blank fills the cavity 6, the extrusion process is completed and the forging is formed.

[0043] The gap 53 between adjacent support dies 52 will not affect the forming of the forging. At most, burrs will be formed on the surface of the forging, which can be polished later. The gap 53 between adjacent support dies 52 can be controlled by setting a slider on the control block 511 and opening a slide groove on the inner wall of the control cavity 54. The slider is slidably set in the slide groove, and the inner wall of the slide groove is also provided with a space for the slider to make way during the retraction process of the support die 52. The cooperation between the slider and the slide groove can ensure the gap 53 between the support dies 52 without affecting the retraction of the support die 52.

[0044] During the unloading process of the forging, it is necessary to first control the upper die 2 to slide in the direction away from the lower die 3 through the first oil cylinder. The upper die 2 first drives the control block 511 to slide from the forging area 541 to the partial control part 512 and contact the inner wall of the control inclined groove 522 through the pull rod 51. As the upper die 2 slides, the control block 511 first drives the support die 52 to move and separate from the lower die 3, and then drives the support die 52 to retract inward with the cooperation of the control part 512 and the control inclined groove 522, so that the inner die core 5 is separated from the forging, and then drives the side die 4 to slide and separate from the lower die 3 through the second oil cylinder. After the forging is taken out, the forging is completed. During the unloading process, the friction between the forging and the inner die core 5 and the side die 4 is reduced, thereby extending the service life of the mold for forming hollow shaft forgings.

[0045] Reference Figure 1 and Figure 3The lower mold 3 is provided with a positioning boss 31 for providing positioning for the outward release of the inner mold core 5. The positioning boss 31 is arranged in a truncated cone shape, and the diameter of the positioning boss 31 increases successively in the direction toward the lower mold 3. The support mold 52 is provided with a positioning inclined surface 523 that cooperates with the side wall of the positioning boss 31. When the support mold 52 slides to fit with the lower mold 3, the giving way inclined surface fits with the side wall of the positioning boss 31. With the cooperation of the positioning boss 31 and the giving way inclined surface, a guide positioning is provided for the outward release of the support mold 52, so that the inner mold core 5 can slide to the position where it cooperates with the side mold 4, the lower mold 3 and the extrusion block 21 to form the cavity 6.

[0046] Reference Figure 3 and Figure 5 A placement boss 32 is also provided on the lower die 3. When the inner die core 5 slides to fit with the placement boss 32, the outer diameter of the placement boss 32 is consistent with the outer diameter of the inner die core 5. The placement boss 32 can provide positioning for the position of the blank when it is placed. When the placement boss 32 is located at the inner ring of the blank, during the process of the inner die core 5 sliding to fit with the placement boss 32, the inner die core 5 is not easy to touch the inner ring of the blank, thereby reducing the friction between the inner die core 5 and the blank, thereby extending the service life of the die for forming hollow shaft forgings.

[0047] Reference Figure 3 and Figure 5 In order to ensure the quality of the forged piece, the height of the placement boss 32 above the lower die 3 is relatively short, which makes it difficult for the operator to judge whether the placement boss 32 is located within the inner circle of the blank during the actual placement process. Therefore, the lower die 3 is also provided with a centering mechanism for providing positioning for the centering placement of the blank. The centering mechanism includes a plurality of centering sliders 7 slidably arranged on the lower die 3. In the embodiment of the present application, there are six centering sliders 7, and the six centering sliders 7 are arranged corresponding to the support die 52. The six centering sliders 7 The lower mold 3 is arranged in a circular array with the axis of the lower mold 3 as the center, and the centering slider 7 slides in the vertical direction. The lower mold 3 is provided with a centering groove 71 for the centering slider 7 to slide, and the centering groove 71 passes through the placement boss 32. Since the opening of the centering groove 71 is located on the placement boss 32, when the upper mold 2 slides to the inner mold core 5 and fits with the placement boss 32, the inner mold core 5 can close the connection between the centering groove 71 and the outside world, so the setting of the centering slider 7 and the centering groove 71 is not easy to affect the normal use of the mold.

[0048] Reference Figure 3 and Figure 5A centering slope 72 is provided on the side of the centering slider 7 facing the side mold 4. The centering slope 72 provides a guide for the centering placement of the blank, so that the distance between the centering slide groove 71 and the side wall of the placement boss 32 is smaller than the shrinkage of the support mold 52. During the placement of the blank, the blank can slide under the action of the centering slope 72 to fit with the side wall of the centering slider 7. Since the distance between the centering slide groove 71 and the side wall of the placement boss 32 is smaller than the shrinkage of the support mold 52, during the process of the inner mold core 5 sliding to fit with the lower mold 3, the inner mold core 5 is further prevented from contacting the blank, thereby extending the service life of the mold for forming hollow shaft forgings.

[0049] Reference Figure 3 and Figure 5 A positioning ball 73 is slidably connected to the centering slider 7, and the positioning ball 73 slides radially along the lower mold 3. A positioning slot 731 is provided on the centering slider 7 for the positioning ball 73 to slide. The opening of the positioning slot 731 is set toward the side mold 4, and the positioning ball 73 is rotatably set in the positioning slot 731. When the inner mold core 5 is in a retracted state, the positioning slot 731 is located outside the centering slot 71. In the absence of other external forces, the end face of the positioning ball 73 facing away from the positioning boss 31 is located on the side of the placement boss 32 away from the positioning boss 31 in the vertical direction. During the placement of the blank, the positioning ball 73 is arranged to push the blank to move to the placement boss 32 located at the inner circle of the blank, and further makes it difficult for the inner die core 5 to contact the blank during the sliding of the inner die core 5 to fit with the lower die 3, thereby extending the service life of the mold for forming hollow shaft forgings. During the separation of the forging from the lower die 3, the positioning ball 73 and the rotation of the positioning ball 73 reduce the friction between the forging and the centering slider 7, so that the centering slider 7 is not easy to scratch the forging, thereby ensuring the quality of the forging.

[0050] Reference Figure 3 and Figure 5 The centering slider 7 is provided with a positioning elastic member for pushing the positioning ball 73 to slide toward the side mold 4. In the embodiment of the present application, the positioning elastic member is a positioning spring 732. One end of the positioning spring 732 is fixed to the inner wall of the positioning slot 731, and the other end of the positioning spring 732 is in contact with the positioning ball 73. The opening of the positioning slot 731 is smaller than the ball diameter of the positioning ball 73. The positioning ball 73 is not easy to slide away from the positioning slot 731. The positioning spring 732 is set so that the positioning ball 73 can maintain a state of being in contact with the inner wall of the opening of the positioning slot 731 without the action of other external forces. Through the setting of the sliding of the positioning ball 73, when the centering slider 7 slides to be accommodated in the centering slot 71, the positioning ball 73 can slide to be accommodated in the positioning slot 731.

[0051] Reference Figure 3 and Figure 5The guide ball 74 is rotatably connected to the centering slider 7, and a guide groove 524 for the guide ball 74 to slide is provided on the bottom wall of the support mold 52. A locking groove 525 for the guide ball 74 to fit is also provided on the bottom wall of the support mold 52. The guide groove 524 is connected to the locking groove 525. The locking groove 525 is located on the side of the guide groove 524 close to the axis of the pull rod 51. The opening of the guide groove 524 increases in sequence in the direction away from the locking groove 525. Under the action of the upper mold 2, the inner mold core 5 first slides until the guide ball 74 fits the inner wall of the guide groove 524, and then as the inner mold core 5 The guide ball 74 can slide along the guide groove 524 when the mold core 5 slides to fit with the placement boss 32, and the guide ball 74 is embedded in the locking groove 525. The setting of the guide ball 74 can reduce the friction between the inner mold core 5 and the centering slider 7, thereby reducing the wear of the centering slider 7 on the inner mold core 5. On the other hand, the guide ball 74 can cooperate with the guide groove 524 and the locking groove 525 to provide positioning for the support mold 52 when the inner mold core 5 is released, further ensuring the gap 53 between adjacent support molds 52 when the inner mold core 5 fits with the placement boss 32. The opening of the guide groove 524 is arranged to increase in sequence in the direction away from the locking groove 525, so that the guide ball 74 can slide along the guide groove 524 to fit into the locking groove 525.

[0052] Reference Figure 3 , Figure 5 and Figure 6 The two adjacent centering sliders 7 are fixed by connecting blocks 75, and the lower mold 3 is provided with connecting grooves 751 for the connecting blocks 75 to slide, and the connecting grooves 751 are connected with the centering grooves 71. Through the setting of the connecting blocks 75 and the connecting grooves 751, on the one hand, the sliding length of the centering slider 7 is limited, so that the centering slider 7 is not easy to slide and separate from the lower mold 3, and on the other hand, the centering slider 7 can slide synchronously, thereby improving the linkage of the centering mechanism.

[0053] Reference Figure 5 and Figure 6 The lower mold 3 is provided with a centering elastic member for pushing the centering slider 7 to slide toward the outside of the centering slide groove 71. In the embodiment of the present application, the centering elastic member is a centering spring 752. There are six centering springs 752. The six centering springs 752 are arranged in a circular array with the axis of the lower mold 3 as the center. Through the arrangement of the six centering springs 752, the stability of pushing the centering slider 7 to slide is improved. One end of the centering spring 752 is fixed to the inner wall of the connecting slide groove 751, and the other end of the connecting spring is fixed to the connecting block 75.

[0054] Reference Figure 1 , Figure 3 and Figure 5The side mold 4 includes a bottom plate 43 that is fitted with the workbench 1, and an embedding cavity 33 for the bottom plate 43 to be embedded in is reserved between the lower mold 3 and the workbench 1. The centering groove 71 runs through the lower mold 3, and a locking groove 431 is opened on the bottom plate 43. When the side mold 4 slides to fit with the lower mold 3, the bottom plate 43 is embedded in the embedding cavity 33, and the bottom plate 43 fits with the inner wall of the embedding cavity 33. At this time, the locking groove 431 on the bottom plate 43 is connected with the centering groove 71 on the lower mold 3. When the centering slider 7 is received in the centering groove 71 under the action of the inner mold core 5, the end of the centering slider 7 away from the upper mold 2 slides to be embedded in the locking groove 431. The centering slider 7 cooperates with the locking groove 431 to limit the side mold 4 from having a slight movement relative to the lower mold 3 during the extrusion process of the billet by the extrusion block 21, thereby ensuring the quality of the forged part to a certain extent. A centering arc surface 76 is provided on the side of the centering slider 7 away from the centering inclined surface 72 . The centering arc surface 76 facilitates the centering slider 7 to slide into the embedded lock slot 431 .

[0055] Reference Figure 6 The upper die 2 is provided with a rib 22 and a positioning column 23. The rib 22 is coaxially arranged with the upper die 2, and the inner diameter of the rib 22 is consistent with the outer diameter of the side die 4. After the lower die 3 slides, the side die 4 is embedded in the rib 22. Through the setting of the rib 22, the end of the side die 4 away from the workbench 1 is limited, and the side die 4 is further limited to move slightly relative to the lower die 3 during the extrusion process of the extrusion block 21 on the billet, thereby ensuring the quality of the forged piece; there are six positioning columns 23, and the six positioning columns 23 above the die 2 is arranged in a circular array with the axis of the upper mold 2 as the center, and a positioning through hole 44 is correspondingly opened on the side mold 4 to cooperate with the positioning column 23. After the upper mold 2 slides, the positioning column 23 is embedded in the positioning through hole 44, and the positioning column 23 cooperates with the positioning through hole 44 to position the position between the upper mold 2 and the side mold 4, so that the upper mold 2 slides to the outer wall of the side mold 4 and fits the inner wall of the baffle, and the extrusion block 21 is embedded between the inner mold core 5 and the side mold 4, which effectively reduces the wear of the extrusion block 21 on the inner mold core 5 and the side mold 4.

[0056] The implementation principle of the extrusion die without draft angle in the embodiment of the present application is as follows: in the actual forging process, the annular blank is first placed on the lower die 3 in coordination with the centering slider 7, at which time the boss 32 is placed on the inner circle of the blank, and then the side die 4 is controlled to slide to fit with the lower die 3 by the second oil cylinder, and then the sliding of the upper die 2 is controlled by the first oil cylinder. In the process of the control block 511 sliding from the retracted area 543 to the positioning area 542, the upper die 2 first slides to the supporting area 543, and the upper die 2 first slides to the supporting area 543. The positioning bevel 523 on the support die 52 fits with the side wall of the positioning boss 31, and the guide ball 74 is embedded in the guide slot 524. Then, as the upper die 2 slides, the guide ball 74 can slide along the guide slot 524, and the centering slider 7 slides down to the embedded lock slot 431 under the action of the inner die core 5. When the inner die core 5 slides to fit with the placement boss 32, the guide ball 74 is embedded in the locking slot 525, and the inner die core 5 is in an outward state. Then, as the upper die 2 continues to slide, in the process of the control block 511 sliding from the positioning area 542 to the forging area 541, the extrusion block 21 is embedded between the inner die core 5 and the side die 4 to extrude the blank. When the blank fills the cavity 6, the extrusion process is completed and the forging is formed.

[0057] During the unloading process of the forging, the upper die 2 needs to be controlled by the first oil cylinder to slide in the direction away from the lower die 3. The upper die 2 first drives the control block 511 to slide from the forging area 541 to the partial control part 512 and contact the inner wall of the control chute 522 through the pull rod 51. As the upper die 2 slides, the control block 511 first drives the inner die core 5 to move to separate from the lower die 3, and then drives the inner die core 5 to retract inward under the cooperation of the control part 512 and the control chute 522, so that the inner die core 5 Separated from the forging, during this process, the centering slider 7 slides to the positioning slot 731 and is located outside the centering slot 71 under the action of the centering spring 752 and the connecting block 75, and the positioning ball 73 fits with the inner wall of the forging. At this time, the end of the centering slider 7 away from the centering slope 72 is completely received in the centering slot 71, and after the locking of the centering slider 7 on the sliding of the side die 4 is released, the side die 4 is driven by the second cylinder to slide and separate from the lower die 3. After the forging is taken out, the forging is completed.

[0058] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An extrusion die without a draft angle, characterized in that: It comprises an upper mold (2), a lower mold (3) and a side mold (4) which are arranged on a workbench (1); the upper mold (2) and the side mold (4) are slidably arranged on the workbench (1); an extrusion block (21) and an inner mold core (5) are coaxially arranged on one side of the upper mold (2) facing the lower mold (3); the side mold (4) comprises a left mold (41) and a right mold (42) symmetrically arranged on both sides of the lower mold (3); the inner mold core (5) comprises a pull rod (51) and a multi-petal support mold (52); the pull rod (51) is arranged on the upper mold (2); the multi-petal support mold (52) is slidably connected to the pull rod (51); a gap (53) is arranged between adjacent support molds (52); a clearance cavity (521) is arranged on one side of the support mold (52) close to the axis of the pull rod (51); the clearance cavity (521) cooperates with the gap (53) to provide clearance for the contraction of the inner mold core (5); When the inner mold core (5) is fitted with the lower mold (3), the inner mold core (5) is in an outward-expanding state. At this time, the extrusion block (21) is embedded between the inner mold core (5) and the side mold (4). The inner mold core (5) can cooperate with the extrusion block (21), the side mold (4) and the lower mold (3) to form a cavity (6). When the inner mold core (5) is separated from the lower mold (3), the inner mold core (5) is in a retracted state. The pull rod (51) is provided with a control component for controlling the retraction and outward-expanding of the support mold (52). The lower mold (3) is provided with a centering mechanism for providing positioning for the centering of the blank. The lower mold (3) is provided with a positioning boss (31) for positioning the inner mold core (5) outwardly; the positioning boss (31) is arranged in a truncated cone shape, and the diameter of the positioning boss (31) increases gradually in a direction toward the lower mold (3); the support mold (52) is provided with a positioning inclined surface (523) that cooperates with the side wall of the positioning boss (31); when the support mold (52) is fitted with the lower mold (3), the giving way inclined surface fits with the side wall of the positioning boss (31); The lower mold (3) is provided with a placement boss (32), and when the inner mold core (5) slides to fit with the placement boss (32), the outer diameter of the placement boss (32) is consistent with the outer diameter of the inner mold core (5); The centering mechanism comprises a plurality of centering sliders (7) slidably arranged on the lower mold (3), the plurality of centering sliders (7) being arranged in a circular array with the axis of the lower mold (3) as the center, the lower mold (3) being provided with a centering slide groove (71) for the centering slider (7) to slide, the centering slide groove (71) passing through the placement boss (32), and the connection between the centering slide groove (71) and the outside is closed when the upper mold (2) slides to the inner mold core (5) and fits with the lower mold (3), the centering slider (7) is provided with a centering inclined surface (72) on the side facing the side mold (4), the centering inclined surface (72) provides guidance for the centering placement of the blank, and the lower mold (3) is provided with a centering elastic member for pushing the centering slider (7) to slide toward the outside of the centering slide groove (71); The centering slider (7) is slidably connected with a positioning ball (73), and the positioning ball (73) slides radially along the lower mold (3). The centering slider (7) is provided with a positioning groove (731) for the positioning ball (73) to slide, and the opening of the positioning groove (731) is arranged toward the side mold (4). The positioning ball (73) is rotatably arranged in the positioning groove (731). The centering slider (7) is provided with a positioning elastic member for pushing the positioning ball (73) to slide toward the side mold (4). When the inner mold core (5) is in a retracted state, the positioning groove (731) is located outside the centering groove (71), and the end face of the positioning ball (73) facing away from the positioning boss (31) is located on the side of the placement boss (32) away from the positioning boss (31) in the vertical direction. The centering slider (7) is rotatably connected with a guide ball (74), the bottom wall of the support mold (52) is provided with a guide groove (524) for the guide ball (74) to slide, and the bottom wall of the support mold (52) is also provided with a locking groove (525) for the guide ball (74) to fit, the guide groove (524) is connected with the locking groove (525), the locking groove (525) is located on the side of the guide groove (524) close to the axis of the pull rod (51), and the opening of the guide groove (524) increases in sequence in the direction away from the locking groove (525); Two adjacent centering slide blocks (7) are connected via a connecting block (75), and a connecting slide groove (751) for the connecting block (75) to slide is provided on the lower mold (3), and the connecting slide groove (751) is communicated with the centering slide groove (71).

2. The extrusion die without a draft angle according to claim 1, characterized in that: The control member comprises a control block (511) arranged on the pull rod (51); when the upper die (2) slides, the control block (511) can be driven to slide by the pull rod (51); a control cavity (54) for the control block (511) to slide is provided on the support die (52); a control portion (512) is provided on the end surface of the control block (511) facing the upper die (2); the control portion (512) is inclinedly arranged near the end surface of the pull rod (51); a control inclined groove (522) cooperating with the control portion (512) is provided on the support die (52); the control cavity (54) is communicated with the control inclined groove (522), so that the control cavity (54) is sequentially divided into a forging area (541), a positioning area (542) and a retracted area (543) along the direction toward the upper die (2); When the control block (511) is located in the retracted area (543), the inner mold core (5) is in a retracted state under the cooperation of the inclined surface of the control part (512) and the control inclined groove (522), and the inner mold core (5) is separated from the lower mold (3). When the control block (511) is located in the positioning area (542), the inner mold core (5) is fitted with the lower mold (3), and the inner mold core (5) is in an outward state. When the control block (511) is located in the forging area (541), the extrusion block (21) is embedded between the inner mold core (5) and the side mold (4).

3. The extrusion die without a draft angle according to claim 1, characterized in that: The side mold (4) includes a bottom plate (43) fitted with the workbench (1), and an engaging cavity (33) for the bottom plate (43) to engage is reserved between the lower mold (3) and the workbench (1). The centering groove (71) passes through the lower mold (3), and a locking groove (431) is provided on the bottom plate (43). When the side mold (4) slides to fit with the lower mold (3), the bottom plate (43) is embedded in the engaging cavity (33) and the centering groove (71) is connected to the locking groove (431). When the centering slider (7) is received in the centering groove (71) under the action of the inner mold core (5), the end of the centering slider (7) away from the upper mold (2) slides to be embedded in the locking groove (431).

4. The extrusion die without a draft angle according to claim 1, characterized in that: The upper mold (2) is provided with a retaining edge (22) and a positioning column (23); the retaining edge (22) is coaxially arranged with the upper mold (2); the inner diameter of the retaining edge (22) is consistent with the outer diameter of the side mold (4); and the side mold (4) is provided with a positioning through hole (44) that cooperates with the positioning column (23).

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