Sector Graphite Carbon Brush Forming Die and Its Application

Abstract

The present invention discloses a sector-shaped graphite carbon brush forming die, which includes a female die, an upper die punch, and a lower die punch; an axially penetrating special-shaped die cavity is provided at the central part of the female die; the special-shaped die cavity is divided into a first die cavity, a second die cavity, and a third die cavity from top to bottom; both the first die cavity and the third die cavity are cuboid structures with a rectangular longitudinal section; the longitudinal section of the third die cavity is a right trapezoidal structure; the right trapezoid takes the connection part of adjacent die cavities as the upper and lower bottom sides, and the hypotenuse of the right trapezoid is an arc-shaped side, and the radian of the arc-shaped side coincides with the radian of the arc-shaped side of the formed sector-shaped graphite carbon brush. The die disclosed by the present invention not only forms the arc surface of the sector-shaped graphite carbon brush at one time, significantly reducing the subsequent processing procedures, but also avoids the difficulty brought by the need for special processing of the arc surface. The prepared die also has the advantages of good dimensional consistency and high precision, improving work efficiency and reducing processing costs.

Description

Technical Field

[0001] The present invention relates to the field of powder metallurgy molds, and particularly to a forming mold for a sector-shaped graphite carbon brush and its application. Background Art

[0002] At present, due to the fixed pressing direction of ordinary carbon brush products on the market, there will be significant physical property differences in the pressing directions of different materials, which is called the anisotropy of carbon brushes. The flexural strength and resistivity in different directions of the material can reach a difference of 2 to 3 times, so it has a greater impact on the use performance of carbon brushes.

[0003] When the shape of the finished carbon brush required by the customer is a cylindrical structure with a cross-section similar to a sector shape, specifically as Figure 1 shown in the structure, the pressing direction is from the inclined plane directions on both sides, specifically as Figure 2 shown in the direction (the shaded area is the part to be processed). Due to the existence of the cylindrical surface and the inclined planes on both sides, generally, the forming and processing methods and process steps of this carbon brush are as Figure 3 shown. The formed blank needs to go through at least 4 processes to obtain the required shape. The shaded area is the part that needs to be processed. This solution not only has more processing procedures, is difficult to process the cylindrical surface, has a high processing cost, is not conducive to mass production, but also wastes a lot of materials, which is not conducive to environmental protection and energy conservation. Summary of the Invention

[0004] Object of the Invention: In order to solve the problems existing in the prior art, the present invention provides a forming mold for a sector-shaped graphite carbon brush and its application, which solves the problems of many processing procedures, high processing cost, and large material waste in the prior art.

[0005] Technical Solution: To achieve the above object, the present invention can adopt the following technical solution: A forming mold for a sector-shaped graphite carbon brush, comprising a female mold, an upper die punch, and a lower die punch; an axially penetrating special-shaped mold cavity is provided at the center of the female mold; the special-shaped mold cavity is divided into three sections from top to bottom, namely a first mold cavity, a second mold cavity, and a third mold cavity;

[0006] Both the first mold cavity and the third mold cavity are cuboid structures with a rectangular longitudinal section; and the side length at the connection of the first mold cavity and the second mold cavity is greater than the side length at the connection of the second mold cavity and the third mold cavity; the longitudinal section of the second mold cavity is a right trapezoid structure; the right trapezoid takes the connection of adjacent mold cavities as the upper and lower bottom sides, and the hypotenuse of the right trapezoid is an arc-shaped side, and the radian of the arc-shaped side coincides with the radian of the arc-shaped side of the formed sector-shaped graphite carbon brush.

[0007] Furthermore, the female mold is a cylindrical structure.

[0008] Furthermore, there are 2 special-shaped cavities, which are arranged side by side at the central part of the female mold, enabling simultaneous mold opening for multiple products and improving work efficiency.

[0009] Furthermore, a first connecting part protruding outward is provided at the top end of the upper punch; the first connecting part fixes the upper punch to the upper mold holder connecting mechanism above.

[0010] Furthermore, a second connecting part protruding outward is provided at the bottom end of the lower punch; the second connecting part fixes the lower punch to the lower mold holder connecting mechanism below.

[0011] Furthermore, before die stamping, the bottom end of the upper punch is located above the first cavity and at the upper dead point outside it; the top end of the lower punch is located at the lower dead point in the middle of the third cavity; the graphite powder is filled from the top end of the lower punch to the upper surface of the special-shaped cavity; the upper punch and the lower punch move simultaneously for double-axis die pressing, and the upper punch stops moving at the connection between the first cavity and the second cavity; the lower punch stops moving at the connection between the second cavity and the third cavity; after pressing a blank with the same shape as the second cavity, the upper punch retracts to its upper dead point, and the lower punch continues to move upward to push the pressed blank out of the special-shaped cavity.

[0012] Furthermore, a circle of recesses is provided on the outer periphery of the upper part of the upper punch; a circle of recesses is respectively provided on the outer periphery of the lower part of the lower punch; this is used to reduce the frictional resistance between the upper and lower punches and the female mold during the formation of the carbon brush, and at the same time facilitate the discharge of gas during the pressing process.

[0013] Beneficial effects: The present invention has the following advantages: not only is the arc surface formed in one step, significantly reducing subsequent processing procedures, but also avoiding the difficulty brought by the need for special processing of the arc surface. The prepared mold also has the advantages of good dimensional consistency and high precision, improving work efficiency and reducing processing costs. Description of the Drawings

[0014] Figure 1 It is a three-dimensional structural schematic diagram of the finished product sector-shaped graphite carbon brush;

[0015] Figure 2 It is a schematic diagram of the pressing direction of the sector-shaped graphite carbon brush in the prior art;

[0016] Figure 3 It is a schematic process flow diagram for preparing the sector-shaped graphite carbon brush from the blank in the prior art;

[0017] Figure 4 It is a three-dimensional structural schematic diagram of the sector-shaped graphite carbon brush forming mold in Embodiment 1 of the present invention;

[0018] Figure 5Schematic diagram of the connection structure between the sector graphite carbon brush forming die and the die control mechanism in Embodiment 1 of the present invention;

[0019] Figure 6 Schematic diagram of the longitudinal sectional structure of the sector graphite carbon brush forming die before die stamping in Embodiment 1 of the present invention;

[0020] Figure 7 Schematic diagram of the longitudinal sectional structure of the sector graphite carbon brush forming die during die stamping in Embodiment 1 of the present invention;

[0021] Figure 8 Schematic diagram of the longitudinal sectional structure of the sector graphite carbon brush forming die when demolding after stamping in Embodiment 1 of the present invention;

[0022] Figure 9 Schematic diagram of the process flow for preparing the sector graphite carbon brush from the blank after demolding the die in Embodiment 1 of the present invention. Detailed implementation manners

[0023] Embodiment 1:

[0024] Please refer to Figures 4 - 9 As shown, the present invention discloses a sector graphite carbon brush forming die, including a female die 1, an upper die punch 2, and a lower die punch 3; an axially penetrating special-shaped die cavity 4 is provided at the center of the female die 1; the special-shaped die cavity 4 is divided into three sections from top to bottom, namely a first die cavity 41, a second die cavity 42, and a third die cavity 43 in sequence;

[0025] The female die 1 is of a cylindrical structure; there are 2 special-shaped die cavities 4, which are arranged in parallel at the center of the female die 1; it can realize the mold opening of multiple products simultaneously, improving the working efficiency.

[0026] Both the first die cavity 41 and the third die cavity 43 are rectangular parallelepiped structures with a rectangular longitudinal section; and the side length at the connection of the first die cavity 41 and the second die cavity 42 is greater than the side length at the connection of the second die cavity 42 and the third die cavity 43; the longitudinal section of the second die cavity 42 is a right trapezoid structure; the right trapezoid takes the connection of adjacent die cavities as the upper and lower bottom edges, and the hypotenuse of the right trapezoid is an arc-shaped edge, and the radian of the arc-shaped edge coincides with the radian of the arc-shaped edge of the formed sector graphite carbon brush.

[0027] An outwardly protruding first connection part 21 is provided at the top of the upper die punch 2; the first connection part 21 fixes the upper die punch 2 to the upper die holder connection mechanism 22 above.

[0028] An outwardly protruding second connection part 31 is provided at the bottom of the lower die punch 3; the second connection part 31 fixes the lower die punch 3 to the lower die holder connection mechanism 32 below.

[0029] A concave portion is provided around the upper outer periphery of the upper die punch 2; a concave portion is provided around the lower outer periphery of the lower die punch 3 respectively; which is used to reduce the frictional resistance between the upper and lower die punches and the female die during the formation of the carbon brush, and at the same time facilitate the discharge of gas during the pressing process.

[0030] The application of the above-mentioned mold is as follows:

[0031] Before the mold stamping, the bottom end of the upper die punch 2 is located above the first mold cavity 41 and at the upper dead point outside it; the top end of the lower die punch 3 is located at the lower dead point in the middle of the third mold cavity 43; specifically, please refer to Figure 6 shown; the graphite powder material is filled from the top end of the lower die punch 3 to the upper surface of the special-shaped mold cavity 4;

[0032] The upper and lower mold control mechanisms respectively control the upper die punch 2 and the lower die punch 3 to move simultaneously for double-axial mold pressing. The upper die punch 2 stops moving at the connection of the first mold cavity 41 and the second mold cavity 42; the lower die punch 3 stops moving at the connection of the second mold cavity 42 and the third mold cavity 43; specifically, please refer to Figure 7 the shown state;

[0033] After pressing out the blank 5 with the same shape as the second mold cavity 42, the upper die punch 2 retracts to its upper dead point, and the lower die punch 3 continues to move upward to push the pressed blank 5 out of the special-shaped cavity 4; specifically, please refer to Figure 8 the shown state.

[0034] After the blank pressing is completed, through Figure 9 shown, and then through two processing procedures of processing procedure 1 and processing procedure 2, the corresponding sector-shaped graphite carbon brush forming mold can be obtained. Compared with the traditional technology such as Figure 3 shown processing procedure (4 steps), not only the arc surface is formed at one time, significantly reducing the subsequent processing procedures, but also avoiding the difficulty brought by the need for special processing of the arc surface. The prepared mold also has the advantages of good dimensional consistency and high precision, improving work efficiency and reducing processing costs.

Claims

1. A sector-shaped graphite carbon brush forming die, characterized in that It includes an internal mold (1), an upper die punch (2), and a lower die punch (3); an axially penetrating special-shaped mold cavity (4) is provided at the central part of the internal mold (1); the special-shaped mold cavity (4) is divided into three sections from top to bottom, which are the first mold cavity (41), the second mold cavity (42), and the third mold cavity (43) in sequence; Both the first mold cavity (41) and the third mold cavity (43) are rectangular parallelepiped structures with a rectangular longitudinal section; and the side length at the connection between the first mold cavity (41) and the second mold cavity (42) is greater than the side length at the connection between the second mold cavity (42) and the third mold cavity (43); the longitudinal section of the second mold cavity (42) is a right trapezoid structure; the right trapezoid takes the connections with adjacent mold cavities as the upper and lower bases, and the hypotenuse of the right trapezoid is an arc-shaped side, and the radian of the arc-shaped side coincides with the radian of the arc-shaped side of the formed mold sector graphite carbon brush; a concave part is provided on the outer periphery of the upper part of the upper die punch (2); a concave part is provided on the outer periphery of the lower part of the lower die punch (3); the internal mold (1) is a cylindrical structure; there are 2 special-shaped mold cavities (4), which are arranged side by side at the central part of the internal mold (1).

2. The sector-shaped graphite carbon brush forming die according to claim 1, wherein: A first connecting part (21) protruding to both sides is provided at the top end of the upper die punch (2); the first connecting part (21) fixes the upper die punch (2) to the upper die holder connecting mechanism (22) above.

3. The sector-shaped graphite carbon brush forming die according to claim 1, characterized in that: A second connecting part (31) protruding to both sides is provided at the bottom end of the lower die punch (3); the second connecting part (31) fixes the lower die punch (3) to the lower die holder connecting mechanism (32) below.

4. Application of the sector-shaped graphite carbon brush forming die according to claim 1, characterized in that Before die stamping, the bottom end of the upper die punch (2) is located at the upper dead center outside the first mold cavity (41) and above it; the top end of the lower die punch (3) is located at the lower dead center at the middle part height inside the third mold cavity (43); the graphite powder material is filled from the top end of the lower die punch (3) to the upper surface of the special-shaped mold cavity (4); the upper die punch (2) and the lower die punch (3) move simultaneously for double-axial die pressing, and the upper die punch (2) stops moving at the connection between the first mold cavity (41) and the second mold cavity (42); the lower die punch (3) stops moving at the connection between the second mold cavity (42) and the third mold cavity (43); after pressing out a blank (5) with the same shape as the second mold cavity (42), the upper die punch (2) retracts to its upper dead center, and the lower die punch (3) continues to move upward to push the pressed blank (5) out of the special-shaped mold cavity (4).

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