Chamfering-free forging die for bevel gear

Abstract

The utility model particularly relates to a chamfering-free forging die for a bevel gear, and belongs to the technical field of dies. The chamfering-free forging die of the bevel gear comprises a die body, the die body comprises a first face and is provided with a cavity, an opening of the cavity is formed in the first face, the cavity comprises a frustum-shaped peripheral wall, the large-diameter side of the peripheral wall is close to the first face, and a plurality of protrusions are arranged on the peripheral wall in the circumferential direction of the peripheral wall at intervals. A tooth portion forming cavity used for forming a tooth portion of the bevel gear is formed between every two adjacent protrusions, each protrusion comprises two tooth face forming faces, the tooth face forming faces are used for forming tooth faces of the tooth portion, the tooth face forming faces are connected with the first face through inclined transition faces, and the inclined transition faces are connected to the side, connected to the tooth face forming faces, of the tooth face forming faces to the side, connected to the first face, of the tooth face forming faces. And the inclined transition surface gradually inclines towards the interior of the tooth part forming cavity. By means of the inclined transition face, after the bevel gear is formed, a receding face can be formed between the tooth face and the back cone part, burrs generated during turning cannot affect meshing of the bevel gear, and the bevel gear does not need to be chamfered.

Description

Technical Field

[0001] The utility model belongs to the technical field of molds, and particularly relates to a non-chamfering forging mold for bevel gears. Background Technique

[0002] Bevel gears, abbreviated as conical gears, are often used to achieve power transmission between two intersecting shafts. Die forging is a production process for bevel gears. Generally speaking, it is to use molds to form a cavity by mating. When the molds are mated, an extrusion force is formed on the blank in the cavity, so that the blank can be formed. In order to fully form the back cone part and the large end of the bevel gear, the diameter of the part of the cavity for forming the large end of the bevel gear is usually larger than the designed diameter. Therefore, after forming, it is necessary to perform turning on the formed blank to remove the excess parts of the processed back cone and the large end. However, after turning, burrs are likely to be generated on the side of the tooth part of the bevel gear close to the large end and the back cone. The burrs will hinder the meshing of the bevel gear. Therefore, further, it is also necessary to use a chamfering machine to chamfer the bevel gear to remove the excess burrs. Although this processing technology can ensure the product quality of the bevel gear, the processing procedures are numerous, reducing the production efficiency. Content of the Utility Model

[0003] The purpose of the utility model is to provide a non-chamfering forging mold for bevel gears, and the blank formed by this mold does not need chamfering processing.

[0004] To achieve the above-mentioned utility model purpose, the technical solution adopted by the utility model is: The embodiment of the present application provides a non-chamfering forging mold for bevel gears, including a mold body. The mold body includes a first surface. The mold body is provided with a cavity, and the opening of the cavity is arranged on the first surface. The cavity includes a frustum-shaped peripheral wall. The large-diameter side of the peripheral wall is close to the first surface. Around the circumference of the peripheral wall, a plurality of protrusions are arranged at intervals. A tooth part forming cavity for forming the tooth part of the bevel gear is formed between two adjacent protrusions. The protrusion includes two tooth surface forming surfaces, and the tooth surface forming surfaces are used to form the tooth surfaces of the tooth part. The tooth surface forming surfaces are connected to the first surface through an inclined transition surface. From the side where the inclined transition surface is connected to the tooth surface forming surface to the side where it is connected to the first surface, the inclined transition surface gradually inclines towards the tooth part forming cavity.

[0005] In some embodiments, the cavity further includes a transition cavity. The transition cavity is arranged between two adjacent protrusions and is used to connect the back cone part and the tooth part of the bevel gear. The transition cavity is communicated with the tooth part forming cavity. The transition cavity includes two oppositely arranged side wall surfaces, and the side wall surfaces are connected to the tooth surface forming surfaces through a first arc chamfering surface.

[0006] In some embodiments, the inclined transition surface is connected to the side wall surface, and the first arc chamfering surface is connected to the inclined transition surface.

[0007] In some embodiments, from the tooth surface forming surface to the first surface, the width of the inclined transition surface is L, satisfying 1.5 mm ≤ L ≤ 2.5 mm.

[0008] In some embodiments, the cavity further includes a bottom wall, the bottom wall is connected to the peripheral wall, and the bottom wall is provided with a through hole.

[0009] In some embodiments, the tooth surface forming surface and the bottom wall are connected by a first arc transition surface.

[0010] In some embodiments, the tooth surface forming surface and the peripheral wall are connected by a second arc transition surface, and the first arc transition surface and the second arc transition surface are connected.

[0011] In some embodiments, the tooth surface forming surface and the peripheral wall are connected by a second arc transition surface.

[0012] The utility model has the following beneficial effects:

[0013] The inclined transition surface enables an avoidance surface to be formed between the tooth surface and the back cone part after the bevel gear is formed. The avoidance surface starts from one side connected to the tooth surface to the side connected to the back cone part, and the avoidance surface gradually moves away from the tooth surface. The avoidance surface does not participate in the meshing of the bevel gear. When burrs are generated during turning the large end and the back cone part of the bevel gear, the burrs are located at the avoidance surface, so the burrs will not affect the meshing of the bevel gear, making it unnecessary to perform chamfering operations on the bevel gear formed by the mold. Description of the Drawings

[0014] Figure 1 is a structural diagram of a bevel gear forging formed by an existing mold;

[0015] Figure 2 is a structural diagram of the existing bevel gear after turning processing formed by the mold;

[0016] Figure 3 is a schematic diagram of the cooperation between the mold of the utility model and the bevel gear;

[0017] Figure 4 is a structural diagram of the mold of the utility model;

[0018] Figure 5 is Figure 4 an enlarged view of part B;

[0019] Figure 6 is a structural diagram of a bevel gear forging formed by the mold of the utility model;

[0020] Figure 7 is a structural diagram of the bevel gear formed by the mold of the utility model after turning processing.

[0021] Attached drawing reference numerals: 1 - die body, 2 - transition cavity, 3 - tooth part forming cavity, 4 - tooth surface forming surface, 5 - inclined transition surface, 6 - bottom wall, 7 - through hole, 8 - second arc transition surface, 9 - first arc transition surface, 10 - first surface, 11 - first arc chamfer surface, 12 - side wall surface, 13 - avoidance surface, 14 - first mating chamfer, 15 - second mating chamfer, 16 - third mating chamfer. Detailed implementation manners

[0022] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. If not specifically specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0023] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0024] Refer to Figure 4 and Figure 5 As shown in [drawings not specified in the original text] and [drawings not specified in the original text], an embodiment of the present application provides a forging die for bevel gears without chamfering, including a die body 1. The die body 1 includes a first surface 10. The die body 1 is provided with a cavity, and the opening of the cavity is arranged on the first surface 10. The cavity includes a frustum-shaped peripheral wall, and the large-diameter side of the peripheral wall is close to the first surface 10. Around the circumference of the peripheral wall, a plurality of protrusions are arranged at intervals, and a tooth part forming cavity 3 for forming the tooth part of the bevel gear is formed between two adjacent protrusions. The protrusion includes two tooth surface forming surfaces 4, and the tooth surface forming surfaces 4 are used to form the tooth surfaces of the tooth part. The tooth surface forming surfaces 4 are connected to the first surface 10 through an inclined transition surface 5. From the side where the inclined transition surface 5 is connected to the tooth surface forming surface 4 to the side where it is connected to the first surface 10, the inclined transition surface 5 gradually inclines towards the tooth part forming cavity 3.

[0025] The complete cavity is formed by two parts. That is, the die body 1 in the embodiment of the present application is a part of the die. The die may further include a mating die body 1, and the mating die body 1 is also provided with a cavity. When the mating die body 1 and the die body 1 are mated, a complete cavity is formed.

[0026] The first surface 10 is the surface of the die body 1 for contacting the mating die body 1.

[0027] The cavity of the die body 1 is used to form the front cone part of the bevel gear.

[0028] When the blank is in the cavity, the die body 1 and the mating die body 1 are aligned, and pressure is applied to the blank. The peripheral wall enables the blank to form the front cone of the bevel gear, and the tooth forming cavity 3 between the two protrusions enables the blank to form the tooth part of the bevel gear.

[0029] See Figure 1 and Figure 2 , when a bevel gear formed by a conventional die is turned at the large end, burrs are likely to be generated at the A position near the large end and the back cone of the tooth part. The burrs will affect the meshing of the bevel gear, resulting in possible defects such as ridges on the bevel gear.

[0030] See Figure 6 and Figure 7 , in the embodiment of the present application, the inclined transition surface 5 is connected from one side of the tooth surface forming surface 4 to one side of the first surface 10. The inclined transition surface 5 gradually inclines into the tooth forming cavity 3, so that after the bevel gear is formed, an avoidance surface 13 can be formed between the tooth surface and the back cone part. The avoidance surface 13 starts from the side connected to the tooth surface to the side connected to the back cone part, and the avoidance surface 13 gradually moves away from the tooth surface, that is, the avoidance surface 13 does not participate in the meshing of the bevel gear. When turning the large end and the back cone part of the bevel gear, the burrs are generated at the avoidance surface 13, so the burrs will not affect the meshing of the bevel gear, and the bevel gear formed by the die does not need chamfering operation.

[0031] See Figure 3 and Figure 4 , in some embodiments, the cavity further includes a transition cavity 2. The transition cavity 2 is arranged between two adjacent protrusions and is used to connect the back cone part and the tooth part of the bevel gear. The transition cavity 2 is communicated with the tooth forming cavity 3. The transition cavity 2 includes two oppositely arranged side wall surfaces 12, and the side wall surfaces 12 are connected to the tooth surface forming surface 4 through a first arc chamfer surface 11.

[0032] The first arc chamfer surface 11 is a concave arc surface.

[0033] The transition cavity 2 is used to enable the blank to have a flow space to store excess material during the forming of the bevel gear, improving the forming effect, and enabling the blank to form a first mating chamfer 14 near the large end side.

[0034] Under the action of the first arc chamfer surface 11, a first mating chamfer 14 can be formed between the back cone part and the tooth surface. The first mating chamfer 14 does not participate in the meshing of the bevel gear. When turning the large end and the back cone part, the burrs generated are at the first mating chamfer 14, so that the burrs will not affect the meshing of the bevel gear.

[0035] See Figure 5 , in some embodiments, the inclined transition surface 5 is connected to the side wall surface 12, and the first arc chamfer surface 11 is connected to the inclined transition surface 5.

[0036] The inclined transition surface 5 is connected to the side wall surface 12, so that the avoidance surface 13 can be arranged between the back cone part and the tooth part, reducing the risk that the burrs generated by turning the back cone part hinder the meshing of the bevel gear.

[0037] See Figure 5 , in some embodiments, from the tooth surface forming surface 4 to the first surface 10, the width of the inclined transition surface 5 is L, satisfying 1.5 mm ≤ L ≤ 2.5 mm.

[0038] L includes the maximum width and the minimum width.

[0039] If the width of the inclined transition surface 5 is too large, the area of stripping will be large, and it will be difficult to strip the blank after forming. If the width of the inclined transition surface 5 is too small, the avoidance effect of the avoidance surface 13 will be reduced.

[0040] When the width L of the inclined transition surface 5 satisfies 1.5 mm ≤ L ≤ 2.5 mm, while ensuring the avoidance effect of the avoidance surface 13, it is convenient for the blank to be demolded.

[0041] See Figure 4 , in some embodiments, the cavity further includes a bottom wall 6, the bottom wall 6 is connected to the peripheral wall, and the bottom wall 6 is provided with a through hole 7.

[0042] The bottom wall 6 and the peripheral wall cooperate to form the front cone part of the bevel gear.

[0043] The through hole 7 in the bottom wall 6 can be used for a pushing device to push the blank after the blank is formed, facilitating the demolding of the blank.

[0044] See Figure 4 , in some embodiments, the tooth surface forming surface 4 is connected to the bottom wall 6 through a first arc transition surface 9.

[0045] The first arc transition surface 9 is a concave arc surface.

[0046] On the one hand, the first arc transition surface 9 increases the structural strength of the part between the protrusion and the bottom wall 6, thereby increasing the service life of the mold. On the other hand, the first arc transition surface 9 enables the bevel gear to form a second mating chamfer 15, removing the sharp edges of the bevel gear, preventing stress concentration, and improving the machining quality of the bevel gear.

[0047] See Figure 4 , in some embodiments, the tooth surface forming surface 4 is connected to the peripheral wall through a second arc transition surface 8, and the first arc transition surface 9 and the second arc transition surface 8 are connected.

[0048] The second arc transition surface 8 is a concave arc surface.

[0049] On the one hand, the second arc transition surface 8 increases the structural strength of the part between the protrusion and the peripheral wall, thereby increasing the service life of the mold. On the other hand, the second arc transition surface 8 enables the bevel gear to form a third mating chamfer 16, removing the sharp edges of the bevel gear, preventing stress concentration, and improving the machining quality of the bevel gear.

[0050] The first arc transition surface 9 is connected to the second arc transition surface 8, increasing the overall structural strength of the bevel gear.

[0051] The above embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations, variations, modifications, and substitutions made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A chamfer-free forging die for bevel gears, characterized in that: The invention comprises a mold body (1), wherein the mold body (1) comprises a first surface (10), the mold body (1) is provided with a mold cavity, the opening of the mold cavity is provided on the first surface (10), the mold cavity comprises a truncated cone-shaped peripheral wall, the large diameter side of the peripheral wall is close to the first surface (10), and a plurality of protrusions are arranged on the peripheral wall at intervals around the peripheral wall, and a tooth forming cavity (3) for forming the tooth portion of a bevel gear is formed between two adjacent protrusions, the protrusion comprises two tooth surface forming surfaces (4), the tooth surface forming surfaces (4) are used to form the tooth surface of the tooth portion, the tooth surface forming surfaces (4) are connected to the first surface (10) via an inclined transition surface (5), and from the side where the inclined transition surface (5) is connected to the tooth surface forming surface (4) to the side where the inclined transition surface (5) is connected to the first surface (10), the inclined transition surface (5) gradually inclines into the tooth forming cavity (3).

2. The chamfer-free forging die for bevel gears according to claim 1, characterized in that: The mold cavity further comprises a transition cavity (2), wherein the transition cavity (2) is arranged between two adjacent protrusions and is used to connect the back cone portion of the bevel gear with the tooth portion, wherein the transition cavity (2) is communicated with the tooth portion forming cavity (3), and wherein the transition cavity (2) comprises two oppositely arranged side wall surfaces (12), wherein the side wall surface (12) is connected to the tooth surface forming surface (4) via a first arc chamfered surface (11).

3. The chamfer-free forging die for bevel gears according to claim 2, characterized in that: The inclined transition surface (5) is connected to the side wall surface (12), and the first arc chamfered surface (11) is connected to the inclined transition surface (5).

4. The chamfer-free forging die for bevel gears according to claim 1, characterized in that: From the tooth surface forming surface (4) to the first surface (10), the width of the inclined transition surface (5) is L, satisfying 1.5 mm ≤ L ≤ 2.5 mm.

5. The chamfer-free forging die for bevel gears according to claim 1, characterized in that: The mold cavity further comprises a bottom wall (6), the bottom wall (6) is connected to the peripheral wall, and the bottom wall (6) is provided with a through hole (7).

6. The chamfer-free forging die for bevel gears according to claim 5, characterized in that: The tooth surface forming surface (4) is connected to the bottom wall (6) via a first arc transition surface (9).

7. The chamfer-free forging die for bevel gears according to claim 6, characterized in that: The tooth surface forming surface (4) is connected to the peripheral wall via a second circular arc transition surface (8), and the first circular arc transition surface (9) is connected to the second circular arc transition surface (8).

8. The chamfer-free forging die for bevel gears according to claim 1, characterized in that: The tooth surface forming surface (4) is connected to the peripheral wall via a second arc transition surface (8).

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