Split type double-section forming die for powder metallurgy friction body

Abstract

The utility model discloses a powder metallurgy friction body split type double-section forming die which comprises a lower die punch, a die core, a die holder, a bidirectional die sleeve, a pressing ring and an upper die punch, the die core and the bidirectional die sleeve are assembled into a bidirectional die core through interference fit, and the bidirectional die core, the die holder and the pressing ring are assembled into a middle die through hexagon socket screws; the lower punch is installed on a connecting plate on the lower portion of the forming hydraulic machine and cannot move up and down in the working process. The middle die is sleeved on the lower die punch and then installed in a die pit in the middle of the forming hydraulic machine and moves up and down synchronously with the middle of the forming hydraulic machine in the working process, and the upper die punch is installed on a connecting plate on the upper portion of the forming hydraulic machine after being matched with a die cavity of the middle die and moves up and down synchronously with the upper portion of the forming hydraulic machine in the working process. The split type double-section forming die is provided with the two forming sections, the utilization rate of a die cavity of the die is increased, the service life of the die cavity of the die is prolonged, and the pressing cost of a powder metallurgy friction body is reduced.

Description

Technical Field

[0001] The utility model relates to a split double-section forming die for a powder metallurgy friction body. Background Art

[0002] Powder metallurgy friction bodies are key components of high-speed train brake pads, and the cost of friction body molding dies is an important part of the production and manufacturing cost of brake products. Usually, powder metallurgy friction body green sheets are pressed by molding dies. Since the friction body green sheet material contains a large amount of non-metallic components, there is a strong internal friction between the powders, which makes the powder pressing and molding more difficult. Over time, it is easy to cause wear or damage to the molding section; at the same time, the pressing and molding dies are currently mainly integrated. Once the molding section is damaged, the entire mold needs to be replaced, which not only affects production efficiency and quality, but also increases production costs and safety hazards. Therefore, in the design of the molding die, the impact of its structural form on the service life should be fully considered.

[0003] At present, the common powder metallurgy friction material forming molds have the following problems after practical engineering application:

[0004] 1) The material cost of powder metallurgy friction body molding mold is high and the service life is short, which leads to high production cost of friction body, frequent mold replacement and low production efficiency.

[0005] 2) The molding die adopts an integrated structure, which is heavy and has low replacement efficiency.

[0006] 3) The mold cavity has only one molding section, and the utilization rate of the mold cavity is low. Utility Model Content

[0007] In order to overcome the above-mentioned shortcomings of the prior art, the utility model proposes a powder metallurgy friction body split double-stage forming mold, aiming to increase the service life of the powder metallurgy friction body forming mold, reduce the frequency of mold replacement, and reduce the mold cost and product manufacturing cost.

[0008] The utility model adopts the following technical scheme to solve the technical problems: a powder metallurgy friction body split double-stage forming die, comprising a lower die punch, a die core, a die base, a bidirectional die sleeve, a pressure ring and an upper die punch, wherein the die core and the bidirectional die sleeve are assembled into a bidirectional die core through interference fit, and the bidirectional die core, the die base and the pressure ring are assembled into a middle die through hexagon socket bolts; the lower die punch is mounted on a connecting plate at the bottom of a forming hydraulic press and cannot move up and down during operation; the middle die sleeve is mounted on a die pit in the middle of the forming hydraulic press after the lower die punch, and moves up and down synchronously with the middle of the forming hydraulic press during operation; the upper die punch is mounted on a connecting plate at the top of the forming hydraulic press after cooperating with the middle die cavity, and moves up and down synchronously with the top of the forming hydraulic press during operation.

[0009] Furthermore, the outer wall of the bidirectional mold sleeve is symmetrically provided with a mold sleeve outer wall flange surface, and the inner cavity of the mold base is provided with a mold base inner cavity flange surface. During assembly, the flange surface at the upper end of the bidirectional mold sleeve is completely fitted with the inner ring bottom surface of the pressure ring, and the flange surface at the lower end of the bidirectional mold sleeve is completely fitted with the flange surface of the mold base inner cavity.

[0010] Furthermore, the lower die punch is provided with a lower die punch neck with a smaller cross-sectional dimension and a lower die punch forming portion with a larger cross-sectional dimension, and the cross-sectional dimension of the lower die punch neck is 0.8 to 0.9 times the cross-sectional dimension of the lower die punch forming portion.

[0011] Furthermore, the height of the neck of the lower die punch is 160-180 mm, and the height of the forming portion of the lower die punch is 15-25 mm.

[0012] Furthermore, the height of the mold core is 120-130 mm.

[0013] Furthermore, the upper punch is provided with an upper punch neck with a smaller cross-sectional dimension and an upper punch forming portion with a larger cross-sectional dimension, and the cross-sectional dimension of the upper punch neck is 0.8 to 0.9 times the cross-sectional dimension of the upper punch forming portion.

[0014] Furthermore, the height of the upper punch neck is 100-120 mm, and the height of the upper punch forming portion is 15-25 mm.

[0015] Furthermore, the pressure ring is evenly provided with a plurality of pressure ring countersunk holes, and the hexagon socket bolts cooperate with the pressure ring countersunk holes and the threaded holes of the mold base.

[0016] Furthermore, the mold core, upper die punch and lower die punch are made of high-speed steel, and the mold base, bidirectional mold sleeve and pressure ring are made of structural steel.

[0017] Compared with the prior art, the positive effects of the utility model are:

[0018] The split double-stage molding die of the utility model has two molding sections, which improves the utilization rate and service life of the mold cavity and reduces the pressing cost of the powder metallurgy friction body. The middle mold of the utility model adopts a split structure. When the mold cavity is worn to the limit and needs to be replaced, only the two-way mold cavity needs to be replaced, which improves the mold replacement efficiency and product production efficiency. The split double-stage molding die of the utility model can better distribute the materials of each component of the mold and reduce the overall material cost of the mold. The specific advantages are as follows:

[0019] 1) When the upper section of the split double-stage forming die cavity is working, the lower section is not worn. After the upper section is worn to the limit, it can be replaced with the lower section for continued use. The die cavity has two forming sections, which improves the utilization rate of the die cavity and the service life of the powder metallurgy friction body forming die, and reduces the pressing cost of the powder metallurgy friction body.

[0020] 2) The split two-stage forming middle mold adopts a split structure, and high-quality high-speed steel materials are only used for the mold core directly involved in the forming, while the remaining parts of the middle mold can be made of general structural steel, thereby reducing the overall mold material cost; the pressing mold base and the pressure ring can be recycled, and after the mold cavity is worn to a limit, only the bidirectional mold core needs to be replaced.

[0021] 3) The mold replacement is convenient and quick, which effectively improves product production efficiency.

[0022] 4) Only the side surfaces of the forming parts of the upper and lower punches are in contact with the die cavity, which reduces the contact friction area between the die cavity and the punch, prevents excessive powder from being retained between the punch and the die cavity, and reduces the wear rate of the die. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be described by way of examples with reference to the accompanying drawings, in which:

[0024] Figure 1 It is a schematic diagram of mold forming;

[0025] Figure 2 Schematic diagram of the lower die punch structure;

[0026] Figure 3 Schematic diagram of the mold core structure;

[0027] Figure 4 This is a schematic diagram of the mold base structure;

[0028] Figure 5 It is a schematic diagram of the bidirectional mold sleeve structure;

[0029] Figure 6 It is a schematic diagram of the pressure ring structure;

[0030] Figure 7 Schematic diagram of the upper die punch structure;

[0031] The reference numerals in the figure include: 100-lower punch, 110-lower punch neck, 120-lower punch forming part, 200-mold core, 210-mold cavity, 300-mold base, 310-threaded hole, 320-flange surface of inner cavity of mold base, 400-bidirectional mold sleeve, 410-flange surface of outer wall of mold sleeve, 420-lifting hole, 430-inner cavity of mold sleeve, 500-pressure ring, 510-pressure ring countersunk hole, 600-hexagon socket bolt, 700-powder compact, 800-upper punch, 810-upper punch neck, 820-upper punch forming part. DETAILED DESCRIPTION

[0032] A powder metallurgy friction body split double-stage forming die, such as Figure 1 As shown, it includes: a lower die punch 100, a die core 200, a die base 300, a two-way die sleeve 400, a pressure ring 500, a hexagon socket bolt 600 and an upper die punch 800, wherein:

[0033] like Figure 2 As shown, the lower punch 100 is provided with a lower punch neck 110 with a smaller cross-sectional dimension and a lower punch forming part 120 with a larger cross-sectional dimension. The cross-sectional dimension of the lower punch neck is 0.8 to 0.9 times the cross-sectional dimension of the lower punch forming part; the height of the lower punch neck is 160 to 180 mm, and the height of the lower punch forming part is 15 to 25 mm.

[0034] like Figure 3 As shown, a mold cavity 210 is provided at the center of the mold core 200, and the height of the mold core is 120-130 mm.

[0035] like Figure 4 As shown, a plurality of threaded holes 310 are evenly arranged on the top surface of the mold base 300, and a mold base inner cavity flange surface 320 is arranged in the inner cavity.

[0036] like Figure 5 As shown, the outer wall of the bidirectional mold sleeve 400 is symmetrically provided with mold sleeve outer wall flange surfaces 410, and two end surfaces of the bidirectional mold sleeve are respectively provided with two hanging holes 420, and the mold sleeve inner cavity 430 matches the mold core 200.

[0037] like Figure 6 As shown, the pressing ring 500 is evenly provided with a plurality of pressing ring countersunk holes 510 ; the hexagon socket bolts 600 cooperate with the pressing ring countersunk holes 510 and the threaded holes 310 .

[0038] like Figure 7 As shown, the upper punch 800 is provided with an upper punch neck 810 with a smaller cross-sectional dimension and an upper punch forming portion 820 with a larger cross-sectional dimension; the cross-sectional dimension of the upper punch neck is 0.8 to 0.9 times the cross-sectional dimension of the upper punch forming portion; the height of the upper punch neck is 100 to 120 mm, and the height of the upper punch forming portion is 15 to 25 mm.

[0039] The die core, the upper die punch and the lower die punch are made of high-speed steel, and the die base, the bidirectional die sleeve and the pressure ring are made of structural steel.

[0040] Assembly method of split two-stage forming middle mold:

[0041] 1) The mold core 200 and the bidirectional mold sleeve 400 are fitted with interference fit to form a bidirectional mold core.

[0042] 2) Place the bidirectional mold core in the mold base 300, so that the outer wall flange surface 410 on one side of the bidirectional mold core is completely fitted with the inner cavity flange surface 320 of the mold base, so that the pressure ring 500 is pressed on the mold base 300 and the bidirectional mold sleeve 400, and then fastened with the hexagon socket bolts 600 to form a split two-stage molding middle mold.

[0043] The lower die punch 100 is installed on the lower connecting plate of the hydraulic press, and the lower end of the split two-stage forming middle die cavity 210 is matched with the lower die punch forming part 120 and then installed in the middle die pit of the hydraulic press. Then, the upper die punch forming part 820 is matched with the split two-stage forming middle die cavity 210 and then installed on the upper connecting plate of the press.

[0044] During operation, the lower die punch 100 and the lower part of the press cannot move up and down, and the middle die connected to the middle part of the press can move up and down synchronously. When it moves to the lowest position, the top surface of the middle die is flush with the top surface of the lower die punch. When it moves to the highest position, the top surface of the lower die punch is located at 1 / 2 the height of the middle die. The upper die punch 800 is connected to the upper part of the press and moves up and down synchronously.

[0045] Implementation method:

[0046] 1) Mold pressing method: During the pressing process of the powder compact 700, the mold cavity 210 is most severely worn in the compact forming area. The split double-stage forming middle mold has a lifting or lowering action when working, and the lower die punch 100 is fixed in position. The initial state is that the top surface of the lower die punch forming part is flush with the top surface of the middle die. The pressing steps are as follows:

[0047] Step 1: The middle mold is moved upward to reserve a filler cavity in the upper section of the mold cavity 210, and then fill it with powder.

[0048] Step 2: The upper punch 800 moves downward. When the top surface of the upper punch forming part 820 contacts the powder in the die cavity, the middle die moves downward at 0.5 times the speed of the upper punch to press the powder until the system reaches the set pressure and releases the pressure after the pressure holding time is reached.

[0049] Step 3: The middle die moves downward to make the top surface of the middle die flush with the top surface of the lower die punch forming part 120, so that the friction body compact is completely removed from the die cavity, and the upper die punch 800 moves upward to take out the friction body compact to complete the pressing.

[0050] During the entire pressing process, only the upper half of the mold cavity 210 is involved in the work, and the lower half of the mold cavity 210 is not worn.

[0051] 2) Mold replacement method: When the upper section of the mold cavity 210 is worn to the limit during use, all the hexagon socket bolts 600 on the pressure ring 500 are removed, the pressure ring 500 is removed, and the installation direction of the bidirectional mold core 200 is reversed, so that the original unworn lower section of the mold cavity is in the upper section of the split double-section forming middle mold, and then the bidirectional mold core is fastened to the mold base 300 by the hexagon socket bolts 600 and the pressure ring 500. When both sections of the bidirectional mold core cavity are worn to the limit, all the hexagon socket bolts 600 on the pressure ring 500 are removed, the pressure ring 500 is removed, and a new bidirectional mold core is replaced.

Claims

1. A powder metallurgy friction body split double-stage forming die, characterized in that: It includes a lower die punch, a die core, a die base, a two-way die sleeve, a pressure ring and an upper die punch. The die core and the two-way die sleeve are assembled into a two-way die core through interference fit. The two-way die core, the die base and the pressure ring are assembled into a middle die through hexagon socket bolts. The lower die punch is installed on the connecting plate at the lower part of the forming hydraulic press and cannot move up and down during operation. The middle die sleeve is installed in the die pit in the middle part of the forming hydraulic press after the lower die punch, and moves up and down synchronously with the middle part of the forming hydraulic press during operation. The upper die punch is installed on the connecting plate on the upper part of the forming hydraulic press after cooperating with the middle die cavity, and moves up and down synchronously with the upper part of the forming hydraulic press during operation.

2. The powder metallurgy friction body split double-stage forming die according to claim 1, characterized in that: The outer wall of the two-way mold sleeve is symmetrically provided with a mold sleeve outer wall flange surface, and the inner cavity of the mold base is provided with a mold base inner cavity flange surface. During assembly, the flange surface at the upper end of the two-way mold sleeve is completely fitted with the inner ring bottom surface of the pressure ring, and the flange surface at the lower end of the two-way mold sleeve is completely fitted with the flange surface of the mold base inner cavity.

3. The powder metallurgy friction body split double-stage forming die according to claim 1, characterized in that: The lower die punch is provided with a lower die punch neck with a smaller cross-sectional dimension and a lower die punch forming portion with a larger cross-sectional dimension, and the cross-sectional dimension of the lower die punch neck is 0.8 to 0.9 times of the cross-sectional dimension of the lower die punch forming portion.

4. The powder metallurgy friction body split double-stage forming die according to claim 3, characterized in that: The height of the neck of the lower die punch is 160-180 mm, and the height of the forming part of the lower die punch is 15-25 mm.

5. The powder metallurgy friction body split double-stage forming die according to claim 1, characterized in that: The height of the mold core is 120-130 mm.

6. The powder metallurgy friction body split double-stage forming die according to claim 1, characterized in that: The upper die punch is provided with an upper die punch neck with a smaller cross-sectional dimension and an upper die punch forming portion with a larger cross-sectional dimension, and the cross-sectional dimension of the upper die punch neck is 0.8 to 0.9 times the cross-sectional dimension of the upper die punch forming portion.

7. The powder metallurgy friction body split double-stage forming die according to claim 6, characterized in that: The height of the upper punch neck is 100-120 mm, and the height of the upper punch forming part is 15-25 mm.

8. The powder metallurgy friction body split double-stage forming die according to claim 1, characterized in that: The pressing ring is evenly provided with a plurality of pressing ring countersunk holes, and the hexagon socket bolts are matched with the pressing ring countersunk holes and the threaded holes of the mold base.

9. The powder metallurgy friction body split double-stage forming die according to claim 1, characterized in that: The mold core, upper die punch and lower die punch are made of high-speed steel, and the mold base, bidirectional mold sleeve and pressure ring are made of structural steel.

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