A cemented carbide top hammer pressing mold

Abstract

This utility model discloses a cemented carbide ejector hammer pressing mold, including a die base, a die assembly, a demolding mechanism, and a cooling component. The cooling component includes a first cooling channel passing through the ejector pin and the inside of the square pad, a second cooling channel located inside the four segmented bottom pads, and a cooling drive assembly for circulating the cooling medium through the first and second cooling channels. This utility model achieves temperature reduction of the square pad and segmented bottom pads by setting the first cooling channel inside the square pad and the second cooling channel inside the segmented bottom pads, and by circulating the cooling medium through the first and second cooling channels. This reduces the possibility of mold deformation, lubrication failure, and powder adhesion caused by temperature rise, ensuring dimensional accuracy and pressing quality.

Description

Technical Field

[0001] This utility model belongs to the technical field of top hammer production equipment, and in particular relates to a cemented carbide top hammer pressing and forming mold. Background Technology

[0002] The cemented carbide top-hammer pressing process includes: weighing a precise amount of the mixture according to the design density, volume, and sintering shrinkage rate of the top hammer using a high-precision balance; uniformly pouring the weighed powder into a cleaned molding cavity; starting the press, with the upper punch moving downwards to apply pressure to the powder within the mold; gradually increasing the pressure according to a preset curve, typically divided into two stages: pre-pressing and main pressing. Pre-pressing initially shapes the powder, while main pressing reaches the final molding pressure; when the pressure reaches its maximum value, maintaining the pressure for a period of time allows for full pressure transmission, expels air between powder particles as much as possible, and promotes more complete plastic flow, thereby reducing elastic aftereffects and crack formation; then releasing the pressure, with the upper punch slowly depressurizing and retracting; finally, removing the pressed top-hammer blank from the molding cavity.

[0003] Most cemented carbide ejector pins are formed by cold pressing at room temperature, especially for billets with high cobalt content, as they have good plasticity at room temperature and can be directly pressed. However, in practice, it has been found that when cemented carbide powder flows under high pressure, it rubs against the mold wall, especially at sharp corners, such as the steps of the ejector pin, which easily generates heat. The powder particles undergo plastic deformation under high pressure, and some mechanical energy is converted into heat energy. Especially in automated production lines, if the stamping frequency is too high, the heat cannot dissipate in time and may accumulate and rise in temperature. The sharp transition areas or narrow areas inside the mold cavity may briefly reach 100-200°C. In existing cemented carbide ejector pin pressing molds, such as the cemented carbide ejector pin mold disclosed in authorization announcement number CN207823734U and the cemented carbide ejector pin mold structure disclosed in authorization announcement number CN219425433U, most of them do not have the function of mold heat dissipation. Temperature rise can easily cause local expansion of mold steel and decrease dimensional accuracy, especially significantly affecting the stepped surface of precision ejector hammers; overheating of the mold can also easily cause organic lubricants to decompose and fail, adhere to the mold wall, and aggravate wear; in addition, high temperature can also easily soften the molding agent, leading to difficulty in demolding or scratches on the surface of the blank. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a cemented carbide top hammer pressing mold to solve the technical problems mentioned in the background art.

[0005] This utility model provides the following technical solution: A cemented carbide top hammer pressing mold includes: A die base, wherein a demolding cavity is provided inside the die base, and an opening communicating with the demolding cavity is provided on the upper end face of the die base; The die assembly includes a square pad block located directly above the opening, four segmented bottom pads located around the square pad block, and a die sleeve located at the upper end of the segmented bottom pads. The demolding mechanism, located inside the demolding cavity, includes a push rod. The upper end of the push rod is connected to the middle of the lower end face of the square pad through an opening. The lower end of the push rod is provided with a lifting assembly for vertically moving the push rod and the square pad. The cooling component includes a first cooling channel passing through the top rod and the inside of the square pad, a second cooling channel located inside the four segmented bottom pads, and a cooling drive assembly for circulating the cooling medium through the first cooling channel and the second cooling channel.

[0006] Preferably, the mold sleeve is also fitted with an upper punch, the square pad, and four segmented bottom pads, and the mold sleeve and the lower end face of the upper punch together form a forming cavity.

[0007] Preferably, the lifting assembly includes an annular seat at the bottom of the demolding cavity, and a plurality of lifting telescopic cylinders are equally spaced along its axial direction inside the annular seat. The lifting telescopic cylinders are arranged vertically upward, and the cylinder body of the lifting telescopic cylinder is located inside the annular seat. The piston rods of the plurality of lifting telescopic cylinders are connected to a lifting plate, and the lower end of the push rod is connected to the upper middle part of the lifting plate.

[0008] Preferably, the vertical section of the first cooling channel is located inside the top rod and the lifting plate, and the lower port of the first cooling channel is disposed through the lower end face of the lifting plate. The horizontal section of the first cooling channel is located inside the square pad, and the upper port of the first cooling channel is disposed through one side of the square pad.

[0009] Preferably, the four segmented base pads are integrally formed, and the second cooling channel is distributed in the shape of an inverted frustum inside the segmented base pad. The input end of the second cooling channel is connected to the upper port of the first cooling channel.

[0010] Preferably, the cooling component further includes a third cooling channel disposed inside the mold sleeve. The third cooling channel is cylindrically distributed inside the mold sleeve, and the input end of the third cooling channel is connected to the output end of the second cooling channel.

[0011] Preferably, the cooling drive assembly includes a cooling box containing a cooling medium and a pump for circulating the cooling medium. The inner wall of the cooling box is provided with a refrigeration component. The output end of the pump is connected to the lower port of the first cooling channel, and the output end of the third cooling channel is connected to the interior of the cooling box.

[0012] Preferably, the cooling element is a semiconductor cooling chip.

[0013] Preferably, a first check valve is provided at the upper end of the first cooling channel, and a second check valve is provided at the input end of the second cooling channel.

[0014] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides a cemented carbide top hammer pressing mold, which sets a first cooling channel inside the square pad and a second cooling channel inside the segmented bottom pad. By circulating cooling medium in the first cooling channel and the second cooling channel, the square pad and the segmented bottom pad are cooled down, reducing the possibility of mold deformation, lubrication failure and powder adhesion caused by temperature rise, and ensuring dimensional accuracy and pressing quality.

[0015] (2) The present invention provides a cemented carbide top hammer pressing mold. By setting a demolding mechanism inside the demolding cavity, after pressing, the extension of the lifting telescopic cylinder can drive the top rod and square pad to move upward, thereby lifting the top hammer blank, making it easy to remove and improving the processing efficiency of the alloy top hammer. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Figure 2 This is a schematic diagram of the punching die assembly structure of this utility model.

[0019] Figure 3 This is a schematic diagram of the demolding mechanism of this utility model.

[0020] In the diagram: 1. Die base; 2. Demolding cavity; 3. Opening; 4. Die assembly; 41. Square pad; 42. Split bottom pad; 43. Die sleeve; 44. Upper punch; 45. Forming cavity; 5. Demolding mechanism; 51. Ejector rod; 53. Ring seat; 54. Lifting telescopic cylinder; 55. Lifting plate; 6. Cooling components; 61. First cooling channel; 62. Second cooling channel; 63. Third cooling channel; 64. Spring tube; 65. Cooling box; 66. Pump body; 67. Inlet pipe; 68. Return pipe; 69. First check valve; 610. Second check valve. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0023] This utility model provides a cemented carbide top hammer pressing mold, reference. Figure 1-3 As shown, it includes a die base 1, a demolding cavity 2 is provided inside the die base 1, and an opening 3 communicating with the demolding cavity 2 is provided on the upper end surface of the die base 1. The punch assembly 4 includes a square pad 41 located directly above the opening 3, four segmented bottom pads 42 located around the square pad 41, and a die sleeve 43 located at the upper end of the segmented bottom pads 42. The demolding mechanism 5 is located inside the demolding cavity 2 and includes a push rod 51. The upper end of the push rod 51 is connected to the middle of the lower end face of the square pad 41 through the opening 3. The lower end of the push rod 51 is provided with a lifting assembly for vertically moving the push rod 51 and the square pad 41. The cooling component 6 includes a first cooling channel 61 passing through the top rod 51 and the inside of the square pad 41, a second cooling channel 62 located inside the four segmented bottom pads 42, and a cooling drive assembly for circulating the cooling medium through the first cooling channel 61 and the second cooling channel 62.

[0024] The upper part of the demolding cavity 2 is conical, the lower middle part of the demolding cavity 2 is cylindrical, and the opening 3 is circular and coaxially located directly above the demolding cavity 2. The conical shape of the upper part can improve the support strength of the upper end face of the die base 1 at the opening 3 position.

[0025] The mold sleeve 43 is also fitted with an upper punch 44, and the square pad 41, four segmented bottom pads 42, and the mold sleeve 43 and the lower end face of the upper punch 44 together form a forming cavity 45. The outer sides of the four segmented bottom pads 42 are axially connected to the upper end face of the die base 1 by several fastening bolts.

[0026] The lifting assembly includes an annular seat 53 located at the bottom of the demolding cavity 2. A plurality of lifting telescopic cylinders 54 are evenly spaced along the axial direction inside the annular seat 53. The lifting telescopic cylinders 54 are vertically upward-facing, with their cylinder bodies located inside the annular seat 53. The piston rods of the plurality of lifting telescopic cylinders 54 are connected to a lifting plate 55. The lower end of the push rod 51 is connected to the upper middle part of the lifting plate 55. The upper part of the lifting plate 55 is conical, matching the upper part of the demolding cavity 2, while the lower middle part of the lifting plate 55 is cylindrical, adapting to the lower inner wall of the demolding cavity 2. The plurality of lifting telescopic cylinders 54 extend and retract synchronously. After pressing, the synchronous extension of the plurality of lifting telescopic cylinders 54 drives the push rod 51 and the square pad 41 to move upward, thereby lifting the green hammer blank for easy removal and improving the processing efficiency of the alloy push hammer.

[0027] The vertical section of the first cooling channel 61 is located inside the top rod 51 and the lifting plate 55, and the lower port of the first cooling channel 61 penetrates the lower end face of the lifting plate 55. The horizontal section of the first cooling channel 61 is located inside the square pad 41, and the upper port of the first cooling channel 61 penetrates one side of the square pad 41. A first one-way valve 69 is also provided at the upper port of the first cooling channel 61. The first one-way valve 69 is a one-way liquid outlet valve. The first cooling channel 61 is used to cool the square pad 41 and to deliver cooling medium into the second cooling channel 62. Before and during pressing, the square pad 41 is in its initial state. At this time, the upper port of the first cooling channel 61 is closely aligned and connected with the input end of the second cooling channel 62. The first one-way valve 69 prevents the cooling medium from flowing out of the upper port of the first cooling channel 61 when the square pad 41 is lifted.

[0028] Four segmented base pads 42 are integrally formed. The second cooling channel 62 is distributed inside the segmented base pads 42 in an inverted frustum shape. The input end of the second cooling channel 62 is connected to the upper port of the first cooling channel 61. A second one-way valve 610 is provided at the input end of the second cooling channel 62. The second one-way valve 610 is a one-way liquid inlet valve. The cooling medium can flow from bottom to top in the second cooling channel 62 to cool the four segmented base pads 42. The second one-way valve 610 can prevent the cooling medium from flowing out from the input end of the second cooling channel 62 when the square pad block 41 is lifted.

[0029] The cooling component 6 further includes a third cooling channel 63 disposed inside the mold sleeve 43. The third cooling channel 63 is cylindrically distributed inside the mold sleeve 43, and its input end is connected to the output end of the second cooling channel 62. The output end of the third cooling channel 63 is connected to the interior of the cooling box 65 through a return pipe 68. The cooling medium flowing out from the second cooling channel 62 enters the third cooling channel 63, and the cooling medium can flow from bottom to top within the third cooling channel 63 to cool the mold sleeve 43.

[0030] The cooling component 6 also includes a spring tube 64, which is located within the inner ring of the annular seat 51. The input end of the spring tube 64 is connected to the output end of the pump body 66 via a liquid inlet pipe 67, and the output end of the spring tube 64 is connected to the lower port of the first cooling channel 61. The cooling medium can flow into the spring tube 64 through the liquid inlet pipe 67 and then into the first cooling channel 61. The spring tube 64 is designed so that during demolding, it can extend like a spring as the ejector rod 51 and the lifting plate 55 move upward; after demolding, as the square pad 41 returns to its initial state, it can contract like a spring as the ejector rod 51 and the lifting plate 55 move downward, causing the spring tube 64 to retract to the inner ring position of the annular seat 51. This prevents sections of the ordinary pipe from falling onto the upper surface of the annular seat 51 due to the downward movement of the lifting plate 55, thus avoiding the situation where the lower end of the lifting plate 55 squeezes the ordinary pipe. The spring tube 64 is designed to facilitate pipe storage and prevent it from being squeezed by the lifting plate 55.

[0031] The cooling drive assembly includes a cooling box 65 containing a cooling medium and a pump 66 for circulating the cooling medium. A cooling element is installed on the inner wall of the cooling box 65. The output end of the pump 66 is connected to the lower port of the first cooling channel 61, and the output end of the third cooling channel 63 is connected to the interior of the cooling box 65. The cooling element is selected as a semiconductor cooling chip. During pressing, the cooling medium in the cooling box 65, through the operation of the pump 66, first enters the first cooling channel 61 to cool the opposing pad 41, then enters the second cooling channel 62 to cool the segmented bottom pad 42, and then enters the third cooling channel 63 to cool the mold sleeve 43. Finally, the cooling medium returns to the interior of the cooling box 65 through the return pipe 68 for recooling, and this cycle continues until pressing is complete. The pump 66 does not operate before or during demolding.

[0032] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A cemented carbide ejector hammer pressing mold, characterized in that, include: A die base (1) is provided inside the die base (1), and an opening (3) communicating with the demolding cavity (2) is provided on the upper surface of the die base (1). The die assembly (4) includes a square pad (41) located directly above the opening (3), four segmented bottom pads (42) located around the square pad (41), and a die sleeve (43) located at the upper end of the segmented bottom pads (42). The demolding mechanism (5) is located inside the demolding cavity (2) and includes a push rod (51). The upper end of the push rod (51) is connected to the middle of the lower end face of the square pad (41) through an opening (3). The lower end of the push rod (51) is provided with a lifting assembly for vertically moving the push rod (51) and the square pad (41). The cooling component (6) includes a first cooling channel (61) passing through the top rod (51) and the inside of the square pad (41), a second cooling channel (62) located inside the four split bottom pads (42), and a cooling drive assembly for circulating the cooling medium through the first cooling channel (61) and the second cooling channel (62).

2. The cemented carbide top hammer pressing mold according to claim 1, characterized in that, The lifting assembly includes an annular seat (53) located at the bottom of the demolding cavity (2). Several lifting telescopic cylinders (54) are equally spaced along the axial direction inside the annular seat (53). The lifting telescopic cylinders (54) are arranged vertically upward. The cylinder body of the lifting telescopic cylinder (54) is located inside the annular seat (53). The piston rods of several lifting telescopic cylinders (54) are connected to a lifting plate (55). The lower end of the push rod (51) is connected to the upper middle part of the lifting plate (55).

3. The cemented carbide top hammer pressing mold according to claim 2, characterized in that, The vertical section of the first cooling channel (61) is located inside the top rod (51) and the lifting plate (55), and the lower port of the first cooling channel (61) is provided through the lower end face of the lifting plate (55). The horizontal section of the first cooling channel (61) is located inside the square pad (41), and the upper port of the first cooling channel (61) is provided through one side of the square pad (41).

4. The cemented carbide top hammer pressing mold according to claim 3, characterized in that, The four segmented base pads (42) are integrally formed, and the second cooling channel (62) is distributed in the shape of an inverted frustum inside the segmented base pads (42). The input end of the second cooling channel (62) is connected to the upper port of the first cooling channel (61).

5. The cemented carbide top hammer pressing mold according to claim 4, characterized in that, The cooling component (6) also includes a third cooling channel (63) disposed inside the mold (43). The third cooling channel (63) is cylindrically distributed inside the mold (43), and the input end of the third cooling channel (63) is connected to the output end of the second cooling channel (62).

6. The cemented carbide top hammer pressing mold according to claim 5, characterized in that, The cooling drive assembly includes a cooling box (65) containing a cooling medium and a pump (66) for circulating the cooling medium. The inner wall of the cooling box (65) is provided with a cooling element. The output end of the pump (66) is connected to the lower port of the first cooling channel (61), and the output end of the third cooling channel (63) is connected to the interior of the cooling box (65).

7. The cemented carbide top hammer pressing mold according to claim 6, characterized in that, A first check valve (69) is provided at the upper port of the first cooling channel (61), and a second check valve (610) is provided at the input end of the second cooling channel (62).

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