Powder metallurgy high-density gear forming die

Abstract

The utility model discloses a powder metallurgy high-density gear forming die, which belongs to the technical field of powder metallurgy dies, and comprises a first upper punch, a second upper punch, a middle die, a first lower punch, a second lower punch and a core rod, the middle die is provided with a tooth-shaped die cavity used for forming a gear piece, the first upper punch is provided with a first pressing block used for pressing the front face of the gear piece, and the second upper punch is provided with a second pressing block used for pressing the front face of the gear piece. The second upper punch is provided with a second pressing block used for being pressed on the front face of the gear piece, the first lower punch is provided with a third pressing block used for being pressed on the back face of the gear piece, the second lower punch is provided with a fourth pressing block used for being pressed on the back face of the gear piece, and the core rod is used for forming a shaft hole. According to the utility model, the problem of large pressing area can be effectively solved, the pressing force of a single punch is reduced, and the pressing efficiency is improved; the pressing blocks of the previous punch and the next punch correspond to the gear teeth of the gear piece, so that the gear teeth of the gear piece can be independently pressurized, and the tooth part density can be further improved; the die tooth part die and the non-tooth part die can be detached for independent maintenance, so that the maintenance cost is reduced, and the maintenance time is shortened.

Description

Technical Field

[0001] This utility model belongs to the field of powder metallurgy mold technology, specifically relating to a powder metallurgy high-density gear forming mold. Background Technology

[0002] Existing powder metallurgy gear forming typically employs molds, such as... Figure 1 As shown, the mold design generally includes one middle die, one upper punch, one lower punch, and one mandrel. During gear forming, the gear is completely surrounded by the upper punch, middle die, lower punch, and mandrel, forming a relatively closed space. The upper and lower punches simultaneously apply pressure to the gear, forcing it to undergo plastic deformation. The middle die constrains the outward tendency of the gear material due to the upward and downward pressure. After forming, the upper punch retracts first, and the lower punch, under the action of upward force, forcibly ejects the part from the lower end face of the middle die cavity. Figure 1 and Figure 2 In this process, since the gear component is a single gear, the upper and lower punches directly form the tooth surface, and the upper punch presses the part into the inner cavity of the middle die. Because the upper and lower punches are integral flat structures, the part is mechanically squeezed along its entire length in the straight cylindrical middle die, and the part itself will undergo plastic deformation. Because the existing molds have integral planar structures for the upper and lower punches, they can only improve the overall density of the part and cannot press the teeth separately. Furthermore, the pressing area is large, making it difficult for the machine to press, and the density of the teeth cannot be further improved. Utility Model Content

[0003] The technical problem solved by this utility model is to provide a powder metallurgy high-density gear forming mold that effectively eliminates the need for a large pressing area, reduces pressing force, and improves pressing efficiency.

[0004] Technical solution: To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0005] A powder metallurgy high-density gear forming die is used to form a gear component. The gear component includes a wheel body, a wheel rim, and gear teeth. The wheel body has a shaft hole and includes an upper punch, an upper second punch, a middle die, a lower punch, a lower second punch, and a mandrel. The middle die has a tooth-shaped die cavity for forming the gear component. The upper punch has a first pressing block for pressing the front side of the gear component. The upper second punch has a second pressing block for pressing the front side of the gear component. The lower punch has a third pressing block for pressing the back side of the gear component. The lower second punch has a fourth pressing block for pressing the back side of the gear component. The mandrel is used to form the shaft hole.

[0006] Furthermore, the upper punch is provided with a first through hole for the second pressing block to pass through, and the lower punch is provided with a second through hole for the fourth pressing block to pass through.

[0007] Furthermore, the first pressing block corresponds to the wheel rim and the wheel teeth, the second pressing block corresponds to the wheel body, the third pressing block corresponds to the wheel rim and the wheel teeth, and the fourth pressing block corresponds to the wheel body.

[0008] Furthermore, when forming the gear component, the lower end face of the first pressing block is flush with the lower end face of the second pressing block, and the upper end face of the third pressing block is flush with the upper end face of the fourth pressing block.

[0009] Furthermore, the first pressing block includes a first ring body corresponding to the wheel rim and a first toothed ring corresponding to the wheel teeth, and the third pressing block includes a second ring body corresponding to the wheel rim and a second toothed ring corresponding to the wheel teeth.

[0010] Furthermore, when the first and second upper punches move toward the front of the gear component, the lower end face of the first pressing block is located behind the lower end face of the second pressing block; when the next and second lower punches move toward the back of the gear component, the upper end face of the third pressing block is located behind the upper end face of the fourth pressing block.

[0011] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0012] 1. By setting the upper punch to be divided into upper first punch and upper second punch, and the lower punch to be divided into lower first punch and lower second punch, the problem of large pressing area can be effectively solved, the pressing force of a single punch can be reduced, and the pressing efficiency can be improved.

[0013] 2. The pressing blocks of the upper and lower punches correspond to the gear teeth, and can pressurize the gear teeth separately, which can further improve the tooth density.

[0014] 3. The toothed and non-toothed parts of the mold can be separated for individual repair, reducing maintenance costs and time. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a gear forming mold in the prior art;

[0016] Figure 2 This is a schematic diagram of the gear component structure in this embodiment;

[0017] Figure 3 This is a schematic diagram of the mold structure according to an embodiment of the present utility model;

[0018] Figure 4 This is a longitudinal sectional view of the mold in the embodiment;

[0019] Figure 5 This is a three-dimensional structural diagram of the upper and lower punches in the embodiment;

[0020] Figure 6 This is a cross-sectional view of the module in the embodiment;

[0021] Figure 7 This is a schematic diagram of the punch structure in the embodiment;

[0022] Figure 8 This is a schematic diagram of the two-stroke structure in the embodiment;

[0023] Figure 9 This is a schematic diagram of the punch structure in the embodiment;

[0024] Figure 10 This is a schematic diagram of the two-stroke structure in the embodiment. Detailed Implementation

[0025] The present invention will be further illustrated below with reference to specific embodiments. The embodiments are implemented on the premise of the technical solution of the present invention. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0026] like Figure 2 As shown, the gear component 9 to be manufactured in this embodiment is mainly used in the gearbox of power tools. As a planetary transmission gear, the part itself needs high density and strength. The gear component 9 includes a gear body 91, a gear rim 92 and gear teeth 93. The gear body 91 is provided with a shaft hole 901. The shaft hole 901 is a circular hole located at the center of the gear body 91. The gear rim 92 is located on the outer ring of the gear body 91. The gear teeth 93 include multiple teeth. The multiple teeth are distributed in a ring array on the outer circumference of the gear rim 92. The gear body 91, the gear rim 92 and the gear teeth 93 are integrally connected and formed.

[0027] like Figure 3As shown, the powder metallurgy high-density gear forming mold of this embodiment is used to form the gear part 9. The mold includes an upper punch 1, an upper second punch 2, a middle mold 3, a lower punch 4, a lower second punch 5 and a mandrel 6. The middle mold 3 is generally frustum shaped. The middle mold 3 has a tooth-shaped mold cavity 301 for forming the gear part 9 at the center position. The upper punch 1 and the upper second punch 2 enter the tooth-shaped mold cavity 301 from the top, and the lower punch 4, the lower second punch 5 and the mandrel 6 enter the tooth-shaped mold cavity 301 from the bottom. The upper punch 1 is provided with a first pressing block 11, which is used to press on the front side of the gear part 9. The first pressing block 11 includes a first ring body 111 and a first gear ring 112. The first ring body 111 corresponds to the wheel rim 92. During forming, the first ring body 111 presses on the front side of the wheel rim 92. The first gear ring 112 corresponds to the wheel tooth 93. During forming, the first gear ring 112 presses on the front side of the wheel tooth 93. The upper punch 1 is provided with a first through hole 101, which extends from the upper end face of the upper punch 1 to the lower end face and also passes through the first pressing block 11. The upper second punch 2 is provided with a second pressing block 21, which passes through the upper punch 1 through the first through hole 101. The second pressing block 21 is a hollow cylinder. The second pressing block 21 is provided with a third through hole, the inner diameter of which corresponds to the outer diameter of the mandrel 6. The second pressing block 21 is used to press on the front side of the wheel body 91. The next punch 4 is provided with a third pressing block 41, which is used to press on the back of the gear part 9. The third pressing block 41 includes a second ring body 411 and a second gear ring 412. The second ring body 411 corresponds to the rim 92 and is pressed on the back of the rim 92 during forming. The second gear ring 412 corresponds to the gear teeth 93 and is pressed on the back of the gear teeth 93 during forming. The next punch 4 is provided with a second through hole 401, which extends from the lower end face of the next punch 4 to the upper end face and also passes through the third pressing block 41. The next punch 5 is provided with a fourth pressing block 51, which is used to press on the back of the gear body 91. The fourth pressing block 51 passes through the next punch 4 through the second through hole 401. The fourth pressing block 51 is a hollow cylinder and is provided with a fourth through hole. The inner diameter of the fourth through hole corresponds to the outer diameter of the mandrel 6. The mandrel 6 is used to form the shaft hole 901. The mandrel 6 passes through the lower second punch 5 and the lower punch 4 from bottom to top and then continues to pass through the gear part 9, thereby forming the shaft hole 901 on the wheel body 91. The mandrel 6, which passes through the shaft hole 901, enters the second pressing block 21 through the third through hole.

[0028] When the gear part 9 is formed, the lower end face of the first pressing block 11 is flush with the lower end face of the second pressing block 21, and the upper end face of the third pressing block 41 is flush with the upper end face of the fourth pressing block 51, thereby pressing the metal powder in the tooth mold cavity 301 into the gear part 9. The rear ends of the upper punch 1, upper second punch 2, lower punch 4, and lower second punch 5 are all connected to the press. When the upper punch 1 and upper second punch 2 move toward the front of the gear part 9, the lower end face of the first pressing block 11 is located behind the lower end face of the second pressing block 21. When the lower punch 4 and lower second punch 5 move toward the back of the gear part 9, the upper end face of the third pressing block 41 is located behind the upper end face of the fourth pressing block 51. By adjusting the stroke of the upper punch 1 and the lower punch 4, the amount of powder filling in the area corresponding to the gear tooth 93 in the tooth mold cavity 301 can be increased. Then, a second pressing can be performed to press the area of ​​the gear tooth 93 again, thereby increasing the tooth density.

[0029] 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 principle 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 powder metallurgy high-density gear forming mold for forming a gear component (9), the gear component comprising a gear body (91), a gear rim (92), and gear teeth (93), wherein the gear body (91) is provided with a shaft hole (901), characterized in that, It includes an upper punch (1), an upper second punch (2), a middle die (3), a lower punch (4), a lower second punch (5), and a mandrel (6). The middle die (3) is provided with a tooth-shaped die cavity (301) for forming the gear part (9). The upper punch (1) is provided with a first pressing block (11) for pressing the front of the gear part (9). The upper second punch (2) is provided with a second pressing block (21) for pressing the front of the gear part (9). The lower punch (4) is provided with a third pressing block (41) for pressing the back of the gear part (9). The lower second punch (5) is provided with a fourth pressing block (51) for pressing the back of the gear part (9). The mandrel (6) is used to form the shaft hole (901).

2. The powder metallurgy high-density gear forming mold according to claim 1, characterized in that, The upper punch (1) is provided with a first through hole (101) through which the second pressing block (21) passes, and the lower punch (4) is provided with a second through hole (401) through which the fourth pressing block (51) passes.

3. The powder metallurgy high-density gear forming mold according to claim 2, characterized in that, The first pressing block (11) corresponds to the wheel rim (92) and the wheel tooth (93), the second pressing block (21) corresponds to the wheel body (91), the third pressing block (41) corresponds to the wheel rim (92) and the wheel tooth (93), and the fourth pressing block (51) corresponds to the wheel body (91).

4. The powder metallurgy high-density gear forming mold according to claim 2, characterized in that, When forming the gear part (9), the lower end face of the first pressing block (11) is flush with the lower end face of the second pressing block (21), and the upper end face of the third pressing block (41) is flush with the upper end face of the fourth pressing block (51).

5. The powder metallurgy high-density gear forming mold according to claim 3, characterized in that, The first pressing block (11) includes a first ring body (111) corresponding to the rim (92) and a first tooth ring (112) corresponding to the tooth (93), and the third pressing block (41) includes a second ring body (411) corresponding to the rim (92) and a second tooth ring (412) corresponding to the tooth (93).

6. The powder metallurgy high-density gear forming mold according to claim 1, characterized in that, When the first punch (1) and the second punch (2) move toward the front of the gear (9), the lower end face of the first pressing block (11) is located behind the lower end face of the second pressing block (21). When the next punch (4) and the second punch (5) move toward the back of the gear (9), the upper end face of the third pressing block (41) is located behind the upper end face of the fourth pressing block (51).

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