Forging die for high-stability motorcycle balance shaft

Abstract

The utility model discloses a forging die for a high-stability motorcycle balance shaft, which comprises two die holders, namely a lower die and an upper die, and each die comprises a die block and a boss; half cavities are formed in the two die holders; each half cavity comprises a half shaft cavity, a half shallow balance cavity and a half deep balance cavity; the parting surface comprises a surrounding part, a concave part, a transition part and a convex part, the concave part, the transition part and the convex part are distributed in the length direction of the half-shaft cavity, the distances between the concave part, the transition part and the convex part and the corresponding modules are sequentially increased, the concave part is connected with the side, away from the half-shaft cavity, of the half-deep balance cavity, and the convex part is connected with the side, away from the half-shaft cavity, of the half-shallow balance cavity. According to the forging die for the high-stability motorcycle balance shaft, the distance between the convex part and the corresponding die block is increased, and the distance between the concave part and the corresponding die block is reduced, so that the flash forming position during forging is changed, flashes are concentrated in the middle of the eccentric block, deformation of the corresponding position of the eccentric block of a blank during trimming is avoided, and the quality of a forged product is improved.

Description

Technical Field

[0001] This utility model relates to the field of balance shaft forging technology, and in particular to a forging die for a high-stability motorcycle balance shaft. Background Technology

[0002] A motorcycle balance shaft is a device used to reduce vibration in a motorcycle engine. It generates a reverse vibration force by rotating a shaft equipped with an eccentric weight, thereby reducing engine vibration, improving riding comfort, and helping to extend the engine's lifespan.

[0003] like Figure 1 The diagram shows a schematic of a motorcycle balance shaft in the prior art. The balance shaft 8 includes a long, narrow main shaft 81 and two eccentric blocks 82 distributed along the axial direction of the main shaft 81 on the same side of the main shaft 81. The two eccentric blocks 82 have the same structural dimensions and are both fan-shaped structures coaxial with the main shaft 81. However, their radial angles on the main shaft 81 are different. When forging the blank using a forging die, as shown... Figure 2 As shown, in the two eccentric block 82 forming locations corresponding to the billet, the upper height dimension H1 of one location is greater than the lower height dimension h1, while the upper height dimension h2 of the other location is less than the lower height dimension H2. The difference between H1 and h1, and the difference between H2 and h2, are relatively large. Since a certain gap needs to be left between the cavities of the upper and lower dies during forging to facilitate the formation of flash (the flash formed after forging of the two eccentric blocks 82 is located near the dotted line in the figure), for the forming location of the eccentric block 82, if the height dimension of either the upper or lower part is too small, the flash will have a certain... When forging and trimming the forged workpiece, flash can easily cause material deformation at positions with excessively small height dimensions (i.e., the positions corresponding to h1 and h2), leading to workpiece deformation and affecting the quality of the final product. Furthermore, controlling the gap between the upper and lower dies during mold closing is crucial. Too small a gap, while improving closing accuracy, increases closing pressure and power consumption, and makes it difficult for excess material to flow out of the cavity, forming flash. Too large a gap, on the other hand, causes excessive material to flow out of the cavity, forming thicker flash, which is detrimental to trimming and reduces the quality of the final product.

[0004] Therefore, it is necessary to improve the forging molds for high-stability motorcycle balance shafts in the existing technology. Utility Model Content

[0005] The purpose of this invention is to overcome the defects in the existing technology and provide a forging mold for a highly stable motorcycle balance shaft that ensures forging quality, improves forging precision, reduces forging pressure and power consumption, and lowers costs.

[0006] To achieve the above technical effects, the technical solution of this utility model is as follows: a forging mold for a high-stability motorcycle balance shaft, comprising two mold bases distributed opposite each other along the vertical direction, the two mold bases being a lower mold and an upper mold, the top surface of the lower mold and the bottom surface of the upper mold being the parting surface of the two mold bases, each of the two mold bases comprising a module and a boss integrally connected along the vertical direction, the parting surface being disposed on the boss, the two mold bases being used to connect a mold closing assembly, the mold closing assembly being used to separate and close the lower mold and the upper mold;

[0007] Both mold bases are provided with a semi-cavity, and the cavity opening of the semi-cavity is located on the parting surface. The semi-cavity includes a long strip-shaped semi-shaft cavity and a semi-shallow balance cavity and a semi-deep balance cavity that are connected to the same side of the semi-shaft cavity and are spaced apart along the length of the semi-shaft cavity. The depth of the semi-shallow balance cavity is less than the depth of the semi-deep balance cavity. The semi-cavity, semi-shallow balance cavity and semi-deep balance cavity of the lower mold correspond to and cooperate with the semi-shallow cavity, semi-deep balance cavity and semi-shallow balance cavity of the upper mold, respectively.

[0008] The parting surface includes an enclosing portion, a concave portion, a transition portion, and a convex portion that are connected end to end and surround the opening of the semi-shaped cavity. The enclosing portion is U-shaped, and the semi-shaft cavity is located inside the enclosing portion. The concave portion, the transition portion, and the convex portion are distributed along the length direction of the semi-shaft cavity and the distance from the corresponding module increases sequentially. The concave portion is connected to the side of the semi-deep balance cavity away from the semi-shaft cavity, and the convex portion is connected to the side of the semi-shallow balance cavity away from the semi-shaft cavity.

[0009] Preferably, in order to reduce the gap between the upper mold protrusion and the lower mold recess during mold closing, thereby reducing the thickness of the flash and ensuring the forming quality of the eccentric block while facilitating subsequent edge trimming, the upper mold protrusion and the lower mold recess are arranged adjacent to each other in the mold closing state.

[0010] Preferably, in order to improve forging efficiency, both die holders are provided with two or more half cavities.

[0011] Preferably, in order to improve forging accuracy, reduce mold size, and lower costs, both mold bases are provided with two semi-cavities. The two semi-cavities are a pre-forging semi-cavity and a final forging semi-cavity distributed and arranged adjacent to each other along the length direction perpendicular to the semi-shaft cavity.

[0012] Preferably, in order to facilitate the removal of the forged blank, the lower die is provided with a top hole extending in the vertical direction, and the top of the top hole extends upward to the parting surface of the lower die.

[0013] Preferably, in order to further facilitate the removal of the pre-forged and final-forged billets, the top hole is located between the two half-cavities of the lower die.

[0014] Preferably, in order to ensure mold closing accuracy, both mold bases also include a limiting platform. The limiting platform and the protrusion are integrally connected to the same side of the corresponding module. In the mold closing state, the limiting platforms of the two mold bases abut against each other, and the protrusions of the two mold bases are in clearance fit.

[0015] Preferably, in order to facilitate the containment of excess material during the forging process, at least one of the parting surfaces of the two mold bases is provided with a receiving recess located between the two half cavities.

[0016] Preferably, to prevent excess material from flowing into the top hole during forging, the receiving recess is formed on the upper die and located between the two half cavities.

[0017] Preferably, to prevent excess material from flowing into the top hole during forging, the projection of the recessed area on the horizontal plane is separated from the projection of the top hole on the horizontal plane.

[0018] In summary, compared with the prior art, the forging mold of the high-stability motorcycle balance shaft of this utility model increases the distance between the convex part and the corresponding module and decreases the distance between the concave part and the corresponding module, thereby changing the flash forming position during forging. This concentrates the flash in the middle of the eccentric block, avoiding deformation of the corresponding part of the billet eccentric block during edge trimming, which is beneficial to improving the quality of forged products. Attached Figure Description

[0019] Figure 1 This is a structural diagram of a motorcycle balance shaft using existing technology;

[0020] Figure 2 This is a simplified diagram showing the flash formation positions of the two eccentric blocks after the balance shaft is forged using existing technology.

[0021] Figure 3 This is a schematic diagram of the structure of this utility model in the mold-closed state;

[0022] Figure 4 This is a schematic diagram of the structure of this utility model in its molded state;

[0023] Figure 5 This is a schematic diagram of the lower mold of this utility model;

[0024] Figure 6 This is a structural schematic diagram of the lower mold of this utility model from another perspective;

[0025] Figure 7 This is a top view of the lower mold of this utility model;

[0026] Figure 8 This is a schematic diagram of the upper mold of this utility model;

[0027] Figure 9This is a bottom view of the upper mold of this utility model;

[0028] Figure 10 This is a simplified diagram showing the flash forming positions of the two eccentric blocks of the balance shaft after forging using this utility model;

[0029] In the diagram: 1. Mold base; 11. Module; 12. Boss; 13. Limiting platform; 2. Lower mold; 3. Upper mold; 4. Half cavity; 41. Half shaft cavity; 42. Semi-shallow balance cavity; 43. Semi-deep balance cavity; 5. Parting surface; 51. Enclosing part; 52. Recess; 53. Transition part; 54. Protrusion; 6. Top hole; 7. Accommodating recess; 8. Balance shaft; 81. Main shaft; 82. Eccentric block. Detailed Implementation

[0030] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0031] like Figures 3-10 As shown, the present invention provides a forging mold for a high-stability motorcycle balance shaft, comprising two mold bases 1 arranged opposite each other along the vertical direction. The two mold bases 1 are a lower mold 2 and an upper mold 3, respectively. The top surface of the lower mold 2 and the bottom surface of the upper mold 3 are the parting surfaces 5 of the two mold bases 1. Each mold base 1 includes a module 11 and a boss 12 integrally connected along the vertical direction. The parting surface 5 is disposed on the boss 12. The two mold bases 1 are used to connect a mold closing assembly, which is used to separate and close the lower mold 2 and the upper mold 3.

[0032] Both mold bases 1 are provided with a semi-cavity 4 and the cavity opening of the semi-cavity 4 is located on the parting surface 5. The semi-cavity 4 includes a long strip-shaped semi-shaft cavity 41 and a semi-shallow balance cavity 42 and a semi-deep balance cavity 43 that are connected to the same side of the semi-shaft cavity 41 and are distributed at intervals along the length direction of the semi-shaft cavity 41. The depth of the semi-shallow balance cavity 42 is less than the depth of the semi-deep balance cavity 43. The semi-shaft cavity 41, semi-shallow balance cavity 42 and semi-deep balance cavity 43 of the lower mold 2 correspond to and cooperate with the semi-shaft cavity 41, semi-deep balance cavity 43 and semi-shallow balance cavity 42 of the upper mold 3, respectively.

[0033] The parting surface 5 includes a surrounding portion 51, a recess 52, a transition portion 53, and a protrusion 54 that are connected end to end and surround the opening of the semi-cavity 4. The surrounding portion 51 is U-shaped, and the semi-shaft cavity 41 is located inside the surrounding portion 51. The recess 52, the transition portion 53, and the protrusion 54 are distributed along the length direction of the semi-shaft cavity 41 and the distance from the corresponding module 11 increases sequentially. The recess 52 is connected to the side of the semi-deep balance cavity 43 away from the semi-shaft cavity 41, and the protrusion 54 is connected to the side of the semi-shallow balance cavity 42 away from the semi-shaft cavity 41.

[0034] It should be noted that the mold-closing assembly used to connect the lower mold 2 and the upper mold 3 in this utility model is a conventional technique used by those skilled in the art, typically consisting of a base and a lifting unit (preferably a hydraulic cylinder). The lower mold 2 is fixed to the base, with the boss 12 in the lower mold 2 located directly above the module 11. The upper mold 3 is connected to the output end of the lifting unit, with the boss 12 in the upper mold 3 located directly below the module 11. The lifting unit controls the upper mold 3 to move up and down, thus achieving the closing and opening of the upper mold 3 and the lower mold 2. In the closed state, as... Figure 3 As shown, the blank can be forged. In the mold-parting state, it is convenient to place the blank to be forged on the lower mold 2 or to remove the forged blank from the lower mold 2. More specifically, the positional relationship and connection relationship between the base and the lifting unit in the mold-closing assembly can be found in the announcement number [notation number missing].

[0035] The positional and connection relationships in the Chinese utility model patent CN219402133U will not be elaborated upon here.

[0036] In this invention, both mold bases 1 include an integrally connected module 11 and a boss 12. The projection of the boss 12 on the horizontal plane is located within the projection of the module 11 on the horizontal plane. In this way, the contact area between the upper mold 3 and the lower mold 2 during forging is reduced. Under the requirement of ensuring the same pressure, the power consumption of the lifting unit for forging can be reduced, and the forging cost can be reduced.

[0037] During forging, the half-shaft cavity 41 of the lower die 2 and the half-shaft cavity 41 of the upper die 3 are used to forge the lower and upper halves of the blank corresponding to the main shaft 81, respectively. The two half-shaft cavities 41 cooperate with each other to form the main shaft 81 of the balance shaft 8. The semi-shallow balance cavity 42 of the lower die 2 and the semi-deep balance cavity 43 of the upper die 3 cooperate with each other to form one of the eccentric blocks 82 of the balance shaft 8. The semi-deep balance cavity 43 of the lower die 2 and the semi-shallow balance cavity 42 of the upper die 3 cooperate with each other to form the other eccentric block 82 of the balance shaft 8.

[0038] Because the radial orientation of the two eccentric blocks 82 in the balance shaft 8 is different from that of the main shaft 81, in the forging mold of this utility model, the depth of the semi-shallow balance cavity 42 of the lower mold 2 is less than the depth of the semi-deep balance cavity 43, while the corresponding depth of the semi-deep balance cavity 43 of the upper mold 3 is greater than the depth of the semi-shallow balance cavity 42.

[0039] Unlike existing technologies, in this invention, the parting surface 5 of the lower die 2 and the parting surface 5 of the upper die 3 are both closed-loop multi-faceted structures, mainly composed of an enclosing part 51, a concave part 52, a transition part 53, and a convex part 54. The concave part 52 corresponds to the semi-deep balancing cavity 43, and the convex part 54 corresponds to the semi-shallow balancing cavity 42. In this way, the cavity depth of the semi-deep balancing cavity 43 can be reduced, and the cavity depth of the semi-shallow balancing cavity 42 can be increased, thereby reducing the difference in cavity depth between the semi-shallow balancing cavity 42 and the semi-deep balancing cavity 43. This can change the gap shape between the parting surfaces 5 when the upper die 3 and the lower die 2 are closed, so that the flash corresponding to the forming positions of the two eccentric blocks 82 during forging is mainly concentrated in the middle position of the eccentric blocks 82.

[0040] like Figure 10 As shown, the two flash forming positions are indicated by the dotted lines in the figure. For the first eccentric block 82, the distance between the flash and the top of the eccentric block 82 is M1, and the distance between the flash and the bottom of the eccentric block 82 is N1. For the second eccentric block 82, the distance between the flash and the top of the eccentric block 82 is N2, and the distance between the flash and the bottom of the eccentric block 82 is M2. The difference between M1 and N1 is significantly smaller than the difference between H1 and h1, and the difference between M2 and N2 is significantly smaller than the difference between H2 and h2. This means that the flash is mainly concentrated in the middle of the eccentric block 82 during forging. This facilitates subsequent edge trimming because the flash is far from the eccentric block 82, thus avoiding deformation of the eccentric block 82 during trimming. This helps improve the final product quality.

[0041] A further improvement is that, in the mold-closed state, the protrusion 54 of the upper mold 3 and the recess 52 of the lower mold 2 are arranged close to each other, and the recess 52 of the upper mold 3 and the protrusion 54 of the lower mold 2 are arranged close to each other.

[0042] By adopting the above design, the distance between the openings of the semi-shallow balance cavity 42 and the semi-deep balance cavity 43 in the two mold bases 1 can be reduced in the mold closing state, thereby reducing the thickness of the flash formed at the position of the eccentric block 82 after forging. This facilitates subsequent edge trimming while avoiding deformation of the eccentric block 82 when trimming the flash, thus improving the quality of the final product.

[0043] A further improvement is that both mold bases 1 are provided with more than two half cavities 4.

[0044] This design allows for forging of the blanks at both locations when the upper die 3 and lower die 2 are closed, thus improving forging efficiency.

[0045] Specifically, each of the two mold bases 1 is provided with two semi-cavities 4. The two semi-cavities 4 are a pre-forging semi-cavity 4 and a final forging semi-cavity 4, which are distributed and arranged adjacent to each other along the length direction perpendicular to the semi-shaft cavity 41. Through the above design, the mold can perform pre-forging and final forging treatments on the billet sequentially during billet processing. This improves forging efficiency and processing accuracy through two forging processes. Furthermore, the adjacent arrangement of the pre-forging semi-cavities 4 and the final forging semi-cavities 4 reduces the width dimensions of the upper mold 3 and the lower mold 2, making the device structure more compact and reducing costs.

[0046] A further improvement is that the lower mold 2 is provided with a top hole 6 extending in the vertical direction, and the top of the top hole 6 extends upward to the parting surface 5 of the lower mold 2; the top hole 6 is located between the two half cavities 4 of the lower mold 2.

[0047] With this design, during the forging process, excess material from the billet flows out of the gap between the lower die 2 and the upper die 3, forming a flash located directly above the top hole 6. By installing a push rod inside the top hole 6, after the upper die 3 and the lower die 2 are separated, the push rod is moved upward and acts on the flash, which can pry the pre-forged and final-forged billets on the lower die 2, making it convenient for the mechanical claw to grab the billets for subsequent processing.

[0048] A further improvement is that both mold bases 1 also include a limiting platform 13. The limiting platform 13 and the protrusion are integrally connected to the same side of the corresponding module 11. In the mold closing state, the limiting platforms 13 of the two mold bases 1 abut against each other, and the protrusions 12 of the two mold bases 1 are in clearance fit.

[0049] By adopting this design, the distance between the upper die 3 and the lower die 2 in the mold-closed state can be limited by the limiting platform 13, so as to avoid excessive extrusion of the billet and affect the forging quality of the billet.

[0050] A further improvement is that at least one of the parting surfaces 5 of the two mold bases 1 has a receiving recess 7 located between the two half cavities 4. By setting the receiving recess 7, it is convenient to accommodate excess material during die forging, while minimizing the distance between the upper mold 3 and the lower mold 2, forming a thinner flash, which facilitates subsequent edge trimming.

[0051] A further improvement is that the receiving recess 7 is formed on the upper mold 3 and located between the two half cavities 4; the projection of the receiving recess 7 on the horizontal plane is separated from the projection of the top hole 6 on the horizontal plane.

[0052] This design prevents excess material from flowing into the top hole 6 during forging, thus avoiding interference with the movement of the push rod.

[0053] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A forging die for a high-stability motorcycle balance shaft, comprising two die bases (1) arranged opposite each other along the vertical direction, the two die bases (1) being a lower die (2) and an upper die (3), the top surface of the lower die (2) and the bottom surface of the upper die (3) being the parting surface (5) of the two die bases (1), each of the two die bases (1) comprising a module (11) and a boss (12) integrally connected along the vertical direction, the parting surface (5) being disposed on the boss (12), the two die bases (1) being used to connect a mold closing assembly, the mold closing assembly being used to separate and close the lower die (2) and the upper die (3), characterized in that: Both mold bases (1) are provided with a semi-cavity (4) and the opening of the semi-cavity (4) is located on the parting surface (5). The semi-cavity (4) includes a long strip-shaped semi-shaft cavity (41) and a semi-shallow balance cavity (42) and a semi-deep balance cavity (43) that are connected to the same side of the semi-shaft cavity (41) and are spaced apart along the length direction of the semi-shaft cavity (41). The depth of the semi-shallow balance cavity (42) is less than the depth of the semi-deep balance cavity (43). The semi-shaft cavity (41), semi-shallow balance cavity (42) and semi-deep balance cavity (43) of the lower mold (2) are respectively matched with the semi-shaft cavity (41), semi-deep balance cavity (43) and semi-shallow balance cavity (42) of the upper mold (3). The parting surface (5) includes a surrounding part (51), a recess (52), a transition part (53), and a convex part (54) that are connected end to end and surround the opening of the half cavity (4). The surrounding part (51) is U-shaped. The half shaft cavity (41) is located inside the surrounding part (51). The recess (52), the transition part (53), and the convex part (54) are distributed along the length direction of the half shaft cavity (41) and the distance from the corresponding module (11) increases sequentially. The recess (52) is connected to the side of the half-deep balance cavity (43) away from the half shaft cavity (41), and the convex part (54) is connected to the side of the half-shallow balance cavity (42) away from the half shaft cavity (41).

2. The forging die for a high-stability motorcycle balance shaft according to claim 1, characterized in that: In the closed state, the protrusion (54) of the upper mold (3) is closely adjacent to the concave part (52) of the lower mold (2), and the concave part (52) of the upper mold (3) is closely adjacent to the protrusion (54) of the lower mold (2).

3. The forging die for the high-stability motorcycle balance shaft according to claim 1, characterized in that: Both mold bases (1) are provided with two or more half cavities (4).

4. The forging die for a high-stability motorcycle balance shaft according to claim 3, characterized in that: Both of the mold bases (1) are provided with two half cavities (4). The two half cavities (4) are a pre-forging half cavity (4) and a final forging half cavity (4) that are distributed and arranged adjacent to each other along the length direction perpendicular to the half shaft cavity (41).

5. The forging die for a high-stability motorcycle balance shaft according to claim 4, characterized in that: The lower mold (2) is provided with a top hole (6) extending in the vertical direction, and the top of the top hole (6) extends upward to the parting surface (5) of the lower mold (2).

6. The forging die for a high-stability motorcycle balance shaft according to claim 5, characterized in that: The top hole (6) is located between the two half cavities (4) of the lower mold (2).

7. The forging die for a high-stability motorcycle balance shaft according to claim 5, characterized in that: Both mold bases (1) also include a limiting platform (13). The limiting platform (13) and the protrusion are integrally connected to the same side of the corresponding module (11). In the mold closing state, the limiting platforms (13) of the two mold bases (1) abut against each other, and the protrusions (12) of the two mold bases (1) are in clearance fit.

8. The forging die for a high-stability motorcycle balance shaft according to claim 7, characterized in that: At least one of the parting surfaces (5) of the two mold bases (1) has a receiving recess (7) located between the two half cavities (4).

9. The forging die for a high-stability motorcycle balance shaft according to claim 8, characterized in that: The receiving recess (7) is formed on the upper mold (3) and located between the two half cavities (4).

10. The forging die for a high-stability motorcycle balance shaft according to claim 9, characterized in that: The projection of the receiving recess (7) on the horizontal plane is separated from the projection of the top hole (6) on the horizontal plane.

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