CN111687365A - Claw utmost point preforging assembling die - Google Patents

Abstract

The invention discloses a claw-pole pre-forging combined die. The outer surface of the die core is respectively provided with arc-shaped grooves at positions corresponding to each claw cavity, and both ends of the arc-shaped grooves extend to the two end faces of the die core; The stress ring is provided with an arc-shaped protrusion at each position corresponding to the arc-shaped groove; when the mold core is completely embedded in the pre-stress ring, the arc-shaped protrusion is inserted into the arc-shaped groove, and the arc-shaped protrusion is inserted into the arc-shaped groove. The convex surface of the arc groove is in contact with the groove surface of the arc groove, and the side surface of the arc convex is in contact with the side surface of the arc groove; the convex surface and the groove surface and the annular inner surface of the prestressing ring There is an interference fit between the first annular outer surface of the core. By setting arc-shaped grooves and arc-shaped protrusions, the claw-pole pre-forging combined die can be equipped with two different interferences, which can more flexibly, accurately and effectively adjust the distribution of the prestress of the die core. Under the premise of sufficient strength, a large local pre-tightening force can be generated on the claw cavity of the mold core, which reduces the risk of cracking of the claw cavity and improves the life of the mold.

Description

Claw pole pre-forging combined die

technical field

The invention belongs to the technical field of automobile generators, and in particular relates to a claw pole pre-forging combined die.

Background technique

The claw pole is a key part in automobile generators and is usually formed by hot forging, including upsetting, pre-forging, final forging and trimming. Due to the complex cavity structure of the claw pole pre-forging die core, and the large deformation and load during forming, severe thermo-mechanical fatigue will occur under the action of cyclic thermal stress and mechanical stress. Cracks will then occur.

There is a boss cavity in the center of the claw pole pre-forging die core, and 6-8 claw cavities are distributed in the circumferential direction. The rounded corners on both sides of the claw cavity are small, which is prone to stress concentration, while the boss cavity also has stress concentration due to large stress, and these two parts are often the first to crack. It is difficult to solve the problem that different cavities of the mold core have different prestressing requirements by using the combined mold form of the traditional annular prestressed ring + cylindrical mold core. In order to reduce the risk of cracking of the claw cavity, it is generally necessary to increase the assembly interference. Although the strength of the boss cavity will be improved, an extrusion effect will be formed on the side of the claw cavity, resulting in deformation of the claw cavity, which is more prone to cracking. Increased risk of cracking of prestressed rings. In order to prevent the extrusion effect on the side of the claw cavity and reduce the amount of assembly interference, the strength of the combined mold cannot be guaranteed, and sufficient pre-tightening force is provided for the claw cavity and the boss cavity. Therefore, it is difficult to increase or decrease the preload force by using the traditional combined mold form of annular prestressed ring + cylindrical mold core to improve the strength of the claw cavity and the boss cavity at the same time. The resulting problems of high stress and premature failure of the claw cavity and the boss cavity.

SUMMARY OF THE INVENTION

In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a combined claw-pole pre-forging die, which can generate a large local preload on the inside of the claw cavity on the premise of maintaining the sufficient strength of the boss cavity. Therefore, the prestress distribution on the die core is more reasonable, thereby effectively reducing the stress of the claw cavity and improving the life of the claw pole preforging die.

The technical scheme adopted in the present invention is as follows:

A claw pole pre-forging combined die, comprising a die core and a prestressing ring, the outer surface of the die core is respectively provided with an arc-shaped groove at each position corresponding to the claw cavity, and both ends of the arc-shaped groove extend to the die core respectively The two end faces of the mold core can be embedded in the prestressing ring, and the prestressing ring is provided with arc-shaped protrusions at the positions corresponding to each arc-shaped groove; when the mold core is completely embedded in the prestressing ring, The arc-shaped protrusion is inserted into the arc-shaped groove, the convex surface of the arc-shaped protrusion is fitted with the groove surface of the arc-shaped groove, and a groove fillet is provided between the groove surface and the side surface of the arc-shaped groove There is a convex fillet between the side surface of the arc-shaped convexity and the convex surface. One section of the annular outer surface of the mold core is the first annular outer surface, and the other section is the second annular outer surface. A rounded transition is adopted between the two annular outer surfaces; the interference fit between the convex surface and the groove surface, the interference fit between the annular inner surface of the prestressing ring and the first annular outer surface, the diameter of the second annular outer surface is smaller than the diameter of the first annular outer surface; an annular outer surface fillet is provided between the annular outer surface of the die core and the side surface of the arc-shaped groove, and between the annular inner surface of the prestressing ring and the side surface of the arc-shaped protrusion The inner surface of the ring is rounded; the side of the arc-shaped groove is fitted with the side of the arc-shaped protrusion; the height of the arc-shaped protrusion is greater than the depth of the claw cavity; the height of the first annular outer surface is equal to the height of the arc-shaped protrusion .

Preferably, the interference between the convex surface and the groove surface is 0.20-0.40mm, the interference between the annular inner surface and the first annular outer surface is 0.10-0.30mm, and the convex surface and the concave The interference between the groove surfaces is greater than the interference between the annular inner surface and the first annular outer surface.

Preferably, the interference between the convex surface and the groove surface is 0.05-0.10 mm larger than the interference between the annular inner surface and the first annular outer surface.

Preferably, the radius of the convex fillet is larger than the radius of the groove fillet.

Preferably, the radius of the raised fillet is 4.00-5.00mm, and the radius of the raised fillet is 2.00mm larger than the radius of the groove fillet.

Preferably, the radius of the rounded corners of the annular outer surface is larger than the radius of the rounded corners of the annular inner surface.

Preferably, the radius of the rounded corners of the annular outer surface is 4.00-5.00 mm, and the radius of the rounded corners of the annular outer surface is 2.00 mm larger than the radius of the rounded corners of the annular inner surface.

Preferably, the height of the arc-shaped protrusion is 10.00-20.00 mm greater than the depth of the claw cavity.

Preferably, the diameter of the first annular outer surface is 2.00 mm larger than the diameter of the second annular outer surface.

The present invention has the following beneficial effects:

In the present invention, an arc-shaped groove is designed on the outer surface of the mold core, and each position corresponding to the arc-shaped groove is provided with an arc-shaped protrusion on the prestressing ring. The shaped protrusion is inserted into the arc-shaped groove, and the convex surface of the arc-shaped protrusion fits with the groove surface of the arc-shaped groove. There is an interference fit between the convex surface and the groove surface, and the interference fit between the annular inner surface of the prestressing ring and the first annular outer surface of the die core, so the claw-pole pre-forging combined die of the present invention can be assembled with two different the amount of interference. The height of the arc-shaped protrusion is greater than the depth of the claw cavity; the height of the first annular outer surface is equal to the height of the arc-shaped protrusion, and the diameter of the first annular outer surface is greater than the diameter of the second annular outer surface, which can reduce the mold core and the diameter of the second annular outer surface. The contact area of the prestressing ring increases the unit preload force of the prestressing ring on the core. To sum up, on the premise of maintaining the sufficient strength of the boss cavity, the combined mold of the present invention can generate a large local pre-tightening force on the inside of the claw cavity, so that the prestress distribution on the mold core is more reasonable, thereby effectively reducing the stress of the claw cavity. , Improve the life of the claw pole pre-forging die.

Further, the interference fit between the convex surface and the groove surface is 0.20-0.40mm, and the interference fit between the annular inner surface and the first annular outer surface is 0.10-0.30mm; The interference fit between the groove surfaces is 0.05-0.10mm larger than the fit between the annular inner surface and the first annular outer surface. Considering the stress concentration of the claw cavity of the mold core and the large stress value, the interference between the convex surface and the groove surface is larger than that between the annular inner surface and the annular outer surface. Claw cavities generate greater local preload.

Further, the radius of the raised fillet is greater than the radius of the groove fillet, and the radius of the annular outer surface fillet is greater than the radius of the annular inner surface fillet. Considering the elastic strain of the mold, forming a gap at the rounded corner can prevent a large stress concentration between the arc-shaped protrusion and the arc-shaped groove during use.

Further, the side surfaces of the arc-shaped grooves and the side surfaces of the arc-shaped protrusions are in contact with each other. This can prevent the relative rotation of the die core and the prestressing ring during use, and ensure the accuracy of the forging.

Description of drawings

Fig. 1 is the structural representation after the assembly of the claw pole pre-forging combined die of the present invention;

Fig. 2 is the longitudinal sectional view of the claw pole pre-forging combined die of the present invention after being assembled;

Figure 3 (a) is a schematic diagram of the fillet fit and contact gap of the claw-pole pre-forging combined die of the present invention;

Figure 3(b) is an enlarged view of part A of Figure 3(a);

4 is a schematic diagram of the core structure of the claw pole pre-forging combined die of the present invention;

Figure 5(a) is a schematic view of the prestressed ring structure of the claw-pole pre-forging combined die of the present invention;

Fig. 5(b) is an enlarged view of part B of Fig. 5(a);

Fig. 6 is the stress distribution diagram of the existing claw pole pre-forging combined die;

FIG. 7 is a stress distribution diagram of the claw pole pre-forging combined die of the present invention.

Among them, 1- mold core, 11- arc groove, 12- claw cavity, 13- groove surface, 14- first annular outer surface, 15- groove fillet, 16- boss cavity, 17- annular outer surface Surface fillet, 18-Second annular outer surface, 2-Prestressed ring, 21-Arc-shaped convex, 22-Convex surface, 23-Annular inner surface, 24-Convex fillet, 25-Annular inner surface circle Angle, 3 - Fitting, L ₁ - Height of the arc-shaped protrusion, L ₂ - Height of the first annular outer surface, L ₃ - Height of the arc-shaped groove, D ₁ - Depth of the arc-shaped protrusion, D ₂ - the width of the arc groove, D ₃ - the depth of the arc groove.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Referring to FIGS. 1 to 5( b ), the claw pole pre-forging combined die of the present invention includes a die core 1 and a prestressing ring 2 . The outer surface of the die core 1 is provided with arcs at each position corresponding to the claw cavity 12 . The two ends of the arc-shaped groove 11 respectively extend to the two end faces of the mold core 1; The arc-shaped protrusions 21 are provided at the positions of the arc-shaped protrusions 21; when the mold core 1 is completely embedded in the prestressing ring 2, the arc-shaped protrusions 21 are inserted into the arc-shaped grooves 11, and the convex surfaces 22 of the arc-shaped protrusions 21 are connected with the arc-shaped protrusions 21. The groove surface 13 of the shaped groove 11 is fitted, a groove fillet 15 is provided between the groove surface 13 and the side surface of the arc-shaped groove 11, and a groove fillet 15 is provided between the side surface of the arc-shaped protrusion 21 and the convex surface 22. The convex fillet 24, one section of the annular outer surface of the mold core 1 is the first annular outer surface 14, and the other section is the second annular outer surface 18, and a rounded corner is used between the first annular outer surface 14 and the second annular outer surface 18 Transition; interference fit between the convex surface 22 and the groove surface 13, interference fit between the annular inner surface 23 and the first annular outer surface 14, the diameter of the first annular outer surface 14 is larger than the diameter of the second annular outer surface 18 Diameter; an annular outer surface fillet 17 is provided between the annular outer surface of the mold core 1 and the side surface of the arc-shaped groove 11, and an annular outer surface fillet 17 is provided between the annular inner surface 23 of the prestressing ring 2 and the side surface of the arc-shaped protrusion 21 The inner surface is rounded 25; the side surface of the arc-shaped groove 11 is fitted with the side surface of the arc-shaped protrusion 21; the height L1 _of the arc-shaped protrusion 21 is greater than the depth of the claw cavity 12; the height of the first annular outer surface 14 L ₂ is equal to the height L ₁ of the arcuate protrusion 21 .

As a preferred embodiment of the present invention, the fitting interference between the convex surface 22 and the groove surface 13 is 0.20-0.40 mm, and the fitting interference between the annular inner surface 23 and the first annular outer surface 14 is 0.10 mm -0.30mm; the interference fit between the convex surface 22 and the groove surface 13 is larger than that between the annular inner surface 23 and the first annular outer surface 14 .

As a preferred embodiment of the present invention, the fitting interference between the convex surface 22 and the groove surface 13 is 0.05-0.10 mm larger than the fitting interference between the annular inner surface 23 and the first annular outer surface 14 .

As a preferred embodiment of the present invention, referring to FIG. 2 and FIG. 4 , the bottom surface of the arc-shaped groove 11 is a convex cylindrical surface, and there is a groove fillet 15 between the groove surface 13 and the side surface of the arc-shaped groove 11 . , an annular outer surface fillet 17 is provided between the side surface of the arc-shaped groove 11 and the annular outer surface.

As a preferred embodiment of the present invention, referring to Fig. 2 and Fig. 5(a), Fig. 5(b), the convex surface 22 is a concave cylindrical surface, the convex surface 22 and the groove surface 15 have the same curvature, and are arc-shaped. There is a convex fillet 24 between the side surface of the protrusion 21 and the convex surface 22 , and an annular inner surface fillet 25 is provided between the side surface of the arc-shaped protrusion 21 and the annular inner surface 23 .

As a preferred embodiment of the present invention, the radius of the convex fillet 24 is larger than the radius of the groove fillet 15 .

As a preferred embodiment of the present invention, the radius of the raised fillet 24 is 4.00-5.00 mm, and the radius of the raised fillet 24 is 2.00 mm larger than the radius of the groove fillet 15 .

As a preferred embodiment of the present invention, the radius of the annular outer surface fillet 17 is larger than the radius of the annular inner surface fillet 25 .

As a preferred embodiment of the present invention, the radius of the annular outer surface fillet 17 is 4.00-5.00mm, and the radius of the annular outer surface fillet 17 is 2.00mm larger than the radius of the annular inner surface fillet 25 .

As a preferred embodiment of the present invention, the height L ₁ of the arcuate protrusion 21 is greater than the depth of the claw cavity 12 by 10.00-20.00 mm.

As a preferred embodiment of the present invention, the diameter of the first annular outer surface 17 is larger than the diameter of the second annular outer surface 18 by 2.00 mm.

Example

The claw pole pre-forging combined die in this embodiment is composed of two parts: a die core 1 and a prestressing ring 2 . The groove surface 13 on the mold core 1 is a convex cylindrical surface, there is a groove fillet 15 between the groove surface 13 and the side surface of the arc groove 11, and the side surface of the arc groove 11 and the annular outer surface are There is an annular outer surface fillet 17 between them; the convex surface 22 on the prestressing ring 2 is a concave cylindrical surface, the convex surface 22 has the same curvature as the groove surface 15, and the side surface of the arc convex 21 is the same as the convex surface 21. There are raised fillets 24 between the faces 22. One section of the annular outer surface of the mold core 1 is the first annular outer surface 14, and the other section is the second annular outer surface 18. The first annular outer surface 14 and the second annular outer surface 18 A rounded corner transition is adopted between the two, and an annular inner surface rounded corner 25 is provided between the side surface of the arc-shaped protrusion 21 and the annular inner surface 23 . When in use, the mold core 1 is completely embedded in the prestressing ring 2, the arc-shaped protrusion 21 of the pre-stressing ring 2 is inserted into the arc-shaped groove 11 of the mold core 1, and the convex surface 22 is fitted with the groove surface 13. , the side surface of the arc-shaped protrusion 21 is fitted with the side surface of the arc-shaped groove 11 . The combined mold is assembled with two kinds of interference. The interference between the convex surface 22 on the prestressing ring 2 and the groove surface 13 of the mold core 1 is 0.20-0.40mm; the annular inner surface of the prestressing ring 2 The interference fit between 23 and the first annular outer surface 14 of the mold core 1 is 0.10-0.30 mm.

The characteristics of the mold core 1 are: there are eight symmetrical claw cavities 12 on the mold core 1, a boss cavity 16 in the center, and eight symmetrical arcs are distributed on the outer surface of the mold core corresponding to the position of the claw cavity 12. Groove 11; the height L ₃ of the arc groove 11 is equal to the height of the mold core, the depth D ₃ of the arc groove 11 is 5.00-15.00mm, and the width D ₂ is 20.00-30.00mm. There is a groove fillet 15 with a radius of 2.00-3.00mm between the groove surface 13 and the side surface of the arc-shaped groove 11, and a ring with a radius of 4.00-5.00mm between the side surface of the arc-shaped groove 11 and the annular outer surface. The outer surface fillet 17; the diameter of the first annular outer surface 14 is 2.00mm larger than the diameter of the second annular outer surface 18, and the height L ₂ of the first annular outer surface 14 is equal to the height L ₁ of the arc-shaped protrusion 21; A rounded transition is employed between the annular outer surface 14 and the second annular outer surface 18 .

The characteristics of the prestressing ring 2 are: there are 8 symmetrical arc-shaped protrusions 21 on the pre-stressing ring 2, and the distribution positions of the arc-shaped protrusions 21 correspond to the distribution positions of the arc-shaped grooves 11; The height L1 is _{10.00-20.00mm} greater than the depth of the claw cavity, and the depth D2 of the arc-shaped protrusion 21 is equal to the depth _D3 of the arc _- shaped groove 11, which are both 5-15mm. There is a convex fillet 24 with a radius of 4.00-5.00mm between the convex surface 22 and the side surface of the arc-shaped protrusion 21, and a radius of 2.00-3.00mm between the side surface of the arc-shaped protrusion 21 and the annular inner surface 23. The inner surface of the ring is rounded 25.

Figure 6 shows the equivalent stress distribution diagram of the existing claw-pole pre-forging combined die. When the larger interference of the assembly is 0.26mm, the maximum equivalent stress in the claw cavity area of the die core reaches 1240MPa, mainly concentrated in the claw. On both sides of the part, the maximum equivalent stress of the boss cavity is 1250MPa.

Using the claw-pole pre-forging combined die structure in this embodiment, the interference fit on the convex surface of the prestressing ring is 0.26mm, and the interference on the inner surface of the ring is 0.20mm. The equivalent stress distribution of the die is shown in the figure 7, the maximum equivalent stress on both sides of the claw is 1100MPa, and the maximum equivalent stress of the boss cavity is 1240MPa. By comparing with the existing claw pole pre-forging combined die, it can be found that the claw pole pre-forging combined die of the present invention can make the prestressing ring generate a large local pre-tightening force on the claw cavity of the die core, so that the The maximum equivalent stress is reduced by 11%.

Therefore, by setting arc-shaped grooves on the outer surface of the die core and setting corresponding protrusions on the prestressing ring, the claw-pole pre-forging combined die is assembled with two different interferences, which can be adjusted more flexibly, accurately and effectively The distribution of mold core pre-stress, on the premise of maintaining sufficient strength of the boss cavity, can generate a large local pre-tightening force on the mold core claw cavity, reduce the risk of cracking of the claw cavity, and improve the life of the mold.

Claims (10)

1. A claw pole pre-forging combined die, characterized in that it comprises a core (1) and a prestressing ring (2), and the outer surface of the core (1) is at each position corresponding to the claw cavity (12), respectively. An arc-shaped groove (11) is provided, and both ends of the arc-shaped groove (11) extend to two end faces of the mold core (1) respectively; Corresponding positions are provided with arc-shaped protrusions (21); when the mold core (1) is completely embedded in the prestressing ring (2), the arc-shaped protrusions (21) are inserted into the arc-shaped grooves (11), The convex surface (22) of the arc-shaped protrusion (21) is fitted with the groove surface (13) of the arc-shaped groove (11), and the groove surface (13) is between the side surface of the arc-shaped groove (11). A groove fillet (15) is provided, a convex fillet (24) is provided between the side surface of the arc-shaped protrusion (21) and the convex surface (22), and a section of the annular outer surface of the mold core (1) is the first An annular outer surface (14), the other segment is a second annular outer surface (18), and a rounded transition is used between the first annular outer surface (14) and the second annular outer surface (18); the convex surface (22) There is an interference fit with the groove surface (13), an interference fit between the annular inner surface (23) of the prestressing ring (2) and the first annular outer surface (14), and the second annular outer surface (18) The diameter is smaller than the diameter of the first annular outer surface (14); an annular outer surface fillet (17) is provided between the annular outer surface of the core (1) and the side surface of the arc-shaped groove (11), and the prestressing ring (2) ) is provided with an annular inner surface fillet (25) between the annular inner surface (23) and the side surface of the arc-shaped protrusion (21); the side surface of the arc-shaped groove (11) and the side surface of the arc-shaped protrusion (21) The height of the arc-shaped protrusion (21) is greater than the depth of the claw cavity (12); the height of the first annular outer surface (14) is equal to the height of the arc-shaped protrusion (21). 2 . The claw-pole pre-forging combined die according to claim 1 , wherein the interference fit between the convex surface (22) and the groove surface (13) is 0.20-0.40 mm, and the inner ring is 0.20-0.40 mm. The interference fit between the surface (23) and the first annular outer surface (14) is 0.10-0.30mm, and the interference fit between the convex surface (22) and the groove surface (13) is larger than the annular inner surface (23) Fitting interference with the first annular outer surface (14). 3. A claw-pole pre-forging combined die according to claim 2, characterized in that the interference fit between the convex surface (22) and the groove surface (13) is larger than the annular inner surface (23) and the The interference fit between the first annular outer surfaces (14) is 0.05mm-0.10mm larger. 4. The claw-pole pre-forging combined die according to claim 1, wherein the groove surface (13) is a convex cylindrical surface, and the convex surface (22) is a concave cylindrical surface, The convex surface (13) has the same curvature as the grooved surface (22). 5 . The claw-pole pre-forging combined die according to claim 1 , wherein the radius of the convex fillet ( 24 ) is larger than the radius of the groove fillet ( 15 ). 6 . 6 . The claw-pole pre-forging combined die according to claim 5 , wherein the radius of the raised fillet (24) is 4.00-5.00 mm, and the radius of the raised fillet (24) is larger than that of the groove circle. 7 . The radius of the corner (15) is 2.00mm larger. 7 . The claw-pole pre-forging combined die according to claim 1 , wherein the radius of the annular outer surface fillet ( 17 ) is greater than the radius of the annular inner surface fillet ( 25 ). 8 . 8. The claw-pole pre-forging combined die according to claim 7, wherein the radius of the annular outer surface fillet (17) is 4.00-5.00mm, and the radius of the annular outer surface fillet (17) is larger than that of the annular outer surface fillet (17). The radius of the inner surface fillet (25) is 2.00mm larger. 9 . The claw-pole pre-forging combined die according to claim 1 , wherein the height of the arc-shaped protrusion ( 21 ) is 10.00-20.00 mm greater than the depth of the claw cavity ( 12 ). 10 . 10 . The claw-pole pre-forging combined die according to claim 1 , wherein the diameter of the first annular outer surface ( 14 ) is 2.00 mm larger than the diameter of the second annular outer surface ( 18 ). 11 .

Images