Pressure injection molding mold

Abstract

The utility model discloses a pressure injection molding mold, which is characterized in that a fixed mold comprises a fixed mold seat, a fixed mold plate fixed on the fixed mold seat and a fixed mold core fixedly arranged on the fixed mold plate, and a concave fixed mold cavity is formed on the fixed mold core; the movable mold comprises a movable mold base, a movable mold plate fixed on the movable mold base, and a movable mold core fixed on the movable mold plate; the movable mold core is provided with a movable mold base and a movable mold plate, the ejector plate can slide in the mold closing direction and is installed between the movable mold base and the movable mold plate, the ejector rod is fixedly installed on the ejector plate, the ejector reset spring provides elastic retaining force towards the movable mold base direction for the ejector plate, and the oil cylinder is fixedly arranged on the movable mold plate. The oil cylinder can drive the ejector plate to move towards the movable mold plate, so that the ejector rod ejects a bearing pad blank to be subjected to pressure injection of a composite wear-resistant layer in the movable mold cavity towards the fixed mold, and an ejector roller on an injection molding machine prevents the ejector plate from moving along with the movable mold base during mold opening, so that discharging is achieved. And stable development and timeliness of the project are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of thrust bearing processing, in particular to a pressure injection molding die used for thrust bearing processing. Background Art

[0002] Thrust bearings (tilt pad thrust bearings and fixed pad thrust bearings) are currently widely used in important industrial technologies such as oil extraction and water conservancy generators.

[0003] At present, both at home and abroad, the injection molding process is used, using composite materials (PTFE, PI, PBI, POM, PET and modified materials containing the above materials), mainly PTFE powder raw materials, and the weighed powder raw materials are placed in a specific mold. The powder raw materials are heated and pressurized by the injection molding equipment to achieve certain conditions for compression molding. The structure of the injection mold is relatively complex, and the process conditions are strict. In particular, the molding pressure is high, the operation is more troublesome, and the manufacturing cost is also high. This method has strict requirements for processing equipment and operators. It cannot be processed by common equipment. It has strict requirements for the weighing and feeding of raw materials, and the operating procedures are cumbersome and require manual control. The products produced are not stable enough. Utility Model Content

[0004] In order to overcome the above-mentioned defects, the utility model provides a pressure injection molding mold, which is used to integrally mold a wear-resistant layer on the surface of the bearing pad matrix of the thrust bearing, thereby reducing the production cost of the product, increasing production stability and reliability, and ensuring the stable development and timeliness of the project.

[0005] The utility model adopts a technical solution to solve the technical problem: a pressure injection molding mold, including a fixed mold and a movable mold that can move toward the fixed mold to achieve mold closing with the fixed mold, wherein:

[0006] The fixed mold includes a fixed mold base, a fixed mold plate and a fixed mold core, wherein the fixed mold plate is fixedly installed on the fixed mold base, the fixed mold core is fixedly installed on the side of the fixed mold plate facing the movable mold, a concave fixed mold cavity is formed on the surface of the fixed mold core facing the movable mold, and a sprue communicating with the fixed mold cavity is provided on the fixed mold base, the fixed mold plate and the fixed mold core;

[0007] The movable mold includes a movable mold base, an ejector plate, an ejector rod, a movable mold plate, an oil cylinder, an ejector reset spring and a movable mold core. The movable mold plate is fixedly installed on one side of the movable mold base, and the movable mold core is fixedly installed on the movable mold plate. A concave movable mold cavity is formed on the surface of the movable mold core facing the fixed movable mold. The bearing pad blank that needs to be injected with a composite wear-resistant layer can be inserted into the movable mold cavity tightly against the side wall. The movable mold cavity and the fixed mold cavity are directly connected to form a molding cavity when the mold is closed. The ejector plate can be installed between the movable mold base and the movable mold plate in a linear sliding manner along the mold closing direction. The cylinder body of the oil cylinder is fixedly installed on the movable mold plate, and the piston rod of the oil cylinder The ejector plate is connected to the ejector plate and can drive the ejector plate to move toward the fixed mold cavity. The ejector return spring provides the ejector plate with an elastic return force in the direction away from the movable mold plate. One end of the ejector rod is fixedly mounted on the ejector plate, and the other end of the ejector rod can be slid into the movable mold cavity along the mold closing direction. The other end of the ejector rod can slide along the ejector plate toward the movable mold plate to push the bearing pad blank in the mold cavity to move toward the fixed mold. The movable mold seat is provided with a unloading channel for the ejector rod on the injection molding machine to pass through. The ejector rod on the injection molding machine can prevent the ejector plate from moving synchronously with the movable mold seat in the direction away from the fixed mold.

[0008] As a further improvement of the utility model, the movable mold core is provided with a molding channel which penetrates along the mold closing direction, and a push block is inserted into the molding channel of the movable mold core so as to be able to slide linearly along the mold closing direction. The push block and the molding channel together form a movable mold cavity, and the other end of the push rod is fixedly connected to the push block.

[0009] As a further improvement of the utility model, an exhaust groove is also provided on the side of the push block.

[0010] As a further improvement of the utility model, a compression limit block is fixedly installed on the ejector plate. After the ejector plate moves a set distance relative to the movable template, the compression limit block presses against the movable template to prevent the ejector plate from continuing to move relative to the movable template.

[0011] As a further improvement of the utility model, a plurality of fixed mold cavities are evenly spaced on the fixed mold core, a plurality of movable mold cavities are evenly spaced on the movable mold core, the sprue is located in the middle of each fixed mold cavity, and the movable mold core is also provided with a cold material well directly opposite the sprue, the cold material well is located in the middle of each movable mold cavity, the sprue is connected to the cold material well when the mold is closed, the cold material well is connected to the gate of each movable mold cavity through the runner, the gate is a fan-shaped structure with a width near one end of the movable mold cavity greater than a width near one end of the runner, both ends of the gate are connected to the runner and the movable mold cavity respectively through rounded corners, and a material head ejector is also provided on the ejector plate, and the material head ejector can be inserted into the cold material well of the movable mold core to eject the material head when the mold is opened.

[0012] As a further improvement of the utility model, a mold temperature controller, a movable mold temperature regulating oil circuit and a fixed mold temperature regulating oil circuit are further provided, the movable mold oil inlet of the movable mold temperature regulating oil circuit is located on the side wall of the movable mold core, the movable mold oil outlet of the movable mold temperature regulating oil circuit is located on the side wall of the movable mold plate, the movable mold plate is provided with a avoidance channel directly opposite to the oil inlet on the movable mold core, the fixed mold oil inlet of the fixed mold temperature regulating oil circuit is located on the side wall of the fixed mold core, the fixed mold oil outlet of the fixed mold temperature regulating oil circuit is located on the side wall of the fixed mold plate, the fixed mold plate is provided with a avoidance channel directly opposite to the oil inlet on the fixed mold core, the movable mold temperature regulating oil circuit and the fixed mold temperature regulating oil circuit are both connected with the mold temperature controller, the mold temperature controller respectively adjusts the oil temperature in the movable mold temperature regulating oil circuit and the fixed mold temperature regulating oil circuit, the oil outlet pipeline of the mold temperature controller is respectively connected with the oil inlets located on the side walls of the fixed mold core and the movable mold core, and the oil return pipeline of the mold temperature controller is respectively connected with the oil outlets located on the side walls of the fixed mold plate and the movable mold plate.

[0013] As a further improvement of the utility model, the two ends of the ejection plate respectively extend to a set distance outside the space between the movable template and the ejection mold base, and through holes are respectively provided at the two ends of the ejection plate. The cylinder bodies of the two oil cylinders are respectively fixedly installed on the two side walls of the movable template, and T-shaped pull rods are respectively fixedly installed on the piston rods of the two oil cylinders. The rod portion with a small diameter of the T-shaped pull rod can be slidably inserted into the through hole of the ejection plate, and the end portion with a large size of the T-shaped pull rod is stopped on the surface of the ejection plate on the side facing away from the movable template.

[0014] As a further improvement of the utility model, at least two guide rods are fixedly provided on the ejection plate, and the movable template is provided with a guide through hole extending along the mold closing direction. The guide rods on the ejection plate can be slidably inserted into the guide through holes on the movable template, and the ejection return spring is sleeved on the outside of the guide rods, and both ends of the ejection return spring are tightly pressed against the ejection plate and the surface of the movable template respectively.

[0015] As a further improvement of the utility model, a plurality of buffer pads are fixedly mounted on the side of the ejector plate facing the movable mold seat.

[0016] As a further improvement of the utility model, a cushion block is fixedly mounted on the movable die seat, and the movable die plate is fixedly mounted on the cushion block. The movable die seat, the movable die plate and the cushion block together form a space for accommodating the ejector plate to move.

[0017] The beneficial effects of the utility model are as follows: the utility model applies pressure during the injection molding process so that the plastic continues to be heated and pressurized in the cavity to solidify and form. Through this mold, the molding cycle of the wear-resistant layer can be shortened, the production efficiency can be higher, the dimensional accuracy of the wear-resistant layer can be higher, the surface quality can be better, there is no shrinkage, pores, or material shortage on the surface of the wear-resistant layer, the strength, mechanical properties, and electrical properties of the wear-resistant layer can be improved, the thickness dimensional accuracy of the wear-resistant layer is high, and the flash is very thin. The utility model can be implemented using an injection molding machine, and the requirements for the machine are relatively low. Most ordinary injection molding machines can complete the production, and general multi-material production can be achieved to meet the performance requirements of bearing pads under different working environments. The utility model effectively increases the production stability and reliability of the thrust bearing, ensures the molding accuracy and wear resistance of the wear-resistant layer on the surface of the thrust bearing, and the utility model has high molding efficiency for the wear-resistant layer on the surface of the thrust bearing, ensuring the stable development and timeliness of the project. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a first stereoscopic view of the pressure injection molding mold of the utility model in the mold closing state;

[0019] Figure 2 It is a second stereoscopic view of the pressure injection molding mold of the utility model in the mold closing state;

[0020] Figure 3 It is a stereoscopic diagram of the mold opening state of the pressure injection molding mold of the utility model;

[0021] Figure 4 It is a three-dimensional diagram of a bearing pad blank formed by a pressure injection molding mold of the utility model;

[0022] Figure 5 This is a three-dimensional diagram of the dynamic mold of the pressure injection molding mold used in the utility model;

[0023] Figure 6 This is a first stereoscopic view of a fixed mold of a pressure injection molding mold used in the utility model;

[0024] Figure 7 This is a second stereoscopic view of the fixed mold of the pressure injection molding mold used in the utility model;

[0025] Figure 8 This is the front view of the pressure injection molding mold used in the utility model;

[0026] Fig. 9 for Figure 8 Middle AA section view;

[0027] Fig.10 This is the right side view of the pressure injection molding mold used in the utility model;

[0028] Fig.11 for Fig.10Middle BB section view;

[0029] Fig.12 This is a top view of the pressure injection molding mold used in the utility model;

[0030] Fig.13 It is a schematic diagram of the pressure injection molding principle of the utility model. DETAILED DESCRIPTION

[0031] Embodiment: A pressure injection molding mold comprises a fixed mold 1 and a movable mold 2 that can move toward the fixed mold 1 to achieve mold closing with the fixed mold 1, wherein:

[0032] The fixed mold 1 includes a fixed mold base 11, a fixed mold plate 12 and a fixed mold core 13, wherein the fixed mold plate 12 is fixedly mounted on the fixed mold base 11, and the fixed mold core 13 is fixedly mounted on the side of the fixed mold plate 12 facing the movable mold 2, and a concave fixed mold cavity 311 is formed on the surface of the fixed mold core 13 facing the movable mold 2, and a sprue 14 communicating with the fixed mold cavity 311 is provided on the fixed mold base 11, the fixed mold plate 12 and the fixed mold core 13;

[0033] The movable mold includes a movable mold base 21, a ejector plate 22, an ejector rod 23, a movable mold plate 24, an oil cylinder 25, an ejector reset spring 26 and a movable mold core 27. The movable mold plate 24 is fixedly installed on one side of the movable mold base 21, and the movable mold core 27 is fixedly installed on the movable mold plate 24. A concave movable mold cavity 271 is formed on the surface of the movable mold core 27 facing the fixed movable mold. The bearing pad blank that needs to be injected with a composite wear-resistant layer can be inserted into the movable mold cavity 271 tightly with the side wall. The movable mold cavity 271 and the fixed mold cavity are directly connected to form a molding cavity when the mold is closed. The ejector plate 22 can be installed between the movable mold base 21 and the movable mold plate 24 in a linear sliding manner along the mold closing direction. The cylinder body of the oil cylinder 25 is fixedly installed on the movable mold plate 24. The oil cylinder 25 The piston rod is connected to the ejection plate 22 and can drive the ejection plate 22 to move toward the fixed mold cavity. The ejection return spring 26 provides the ejection plate 22 with an elastic return force in the direction away from the movable mold plate 24. One end of the ejector rod 23 is fixedly mounted on the ejection plate 22, and the other end of the ejector rod 23 can be inserted into the movable mold cavity 271 by sliding along the mold closing direction. The other end of the ejector rod 23 can slide along the ejection plate 22 toward the movable mold plate 24 to push the bearing pad blank in the mold cavity 271 to move toward the fixed mold. The movable mold base 21 is provided with a unloading channel for the ejector rod 4 on the injection molding machine to pass through. The ejector rod 4 on the injection molding machine can prevent the ejection plate 22 from moving synchronously with the movable mold base 21 in the direction away from the fixed mold.

[0034] The bearing pad blank 33 is placed in the movable mold 2 cavity of the mold for positioning, and then the injection molding machine is closed, and the nozzle 5 of the injection molding machine starts to inject and maintain pressure. When the pressure maintenance stage is reached, the oil cylinder 25 is synchronously pulled back to drive the ejector plate 22 to push the ejector rod 23 to apply pressure to the pad to compress the engineering material. A through hole is preferably set on the ejector plate 22, and a T-shaped pull rod 251 is fixedly installed on the piston rod of the oil cylinder 25. The T-shaped pull rod can be slidably penetrated in the through hole of the ejector plate 22, and the large end of the T-shaped pull rod is stopped at the ejector plate 22. The plate 22 faces away from the surface of the movable template 24. The piston rod of the cylinder 25 contracts and moves with the T-shaped pull rod toward the movable template 24, thereby pulling the ejector plate 22 toward the movable template 24 to compress the molding cavity. After the pressure holding is completed, the cylinder 25 is reset, and the ejector plate 22 and the ejector rod 23 thereon move in the opposite direction and reset under the action of the ejector reset spring 26. The mold is opened, and the ejector rod 4 of the injection molding machine pushes the ejector plate 22 to drive the ejector rod 23 to eject the product. After the ejection is completed, the entire compression injection molding process is completed.

[0035] The compression injection molding process combines the injection molding process of thermoplastic materials with the injection molding process of thermosetting materials. During the injection molding process, pressure is applied to allow the plastic to continue to be heated and pressed in the mold cavity to solidify and form. This process can make the molding cycle of the wear-resistant layer 32 shorter and the production efficiency higher. The engineering plastic is first heated and plasticized in the barrel of the injection molding machine. During molding, the plastic is injected into the mold molding cavity at high speed through the pouring system. The incompletely plasticized plastic is compressed by the mold to facilitate the rapid hardening of the plastic part in the molding cavity, thereby shortening the hardening time. The hardening time of pressure injection molding is only equivalent to one-half of that of ordinary injection molding. In addition, the dimensional accuracy of the plastic part is higher, the surface quality is better, and there will be no shrinkage, pores, or material shortage. Because the plastic is heated evenly and cross-linked and hardened sufficiently, the mechanical properties of the plastic part are improved, so that the strength, mechanical properties, and electrical properties of the part are improved, the dimensional accuracy of the plastic part in the height direction is higher, and the flash is thinner. Moreover, this process has low requirements on the machine. Most common injection molding machines can complete the production, and it can be produced through a variety of materials to meet the production needs of bearing pads in different working environments.

[0036] The pressure injection molding die has a simple structure and low manufacturing cost, and can well meet the pressure injection molding production process of the wear-resistant layer 32 on the surface of the thrust bearing.

[0037] The movable mold core 27 is provided with a molding channel that runs through the mold closing direction. A push block 272 is inserted in the molding channel of the movable mold core 27 so as to be able to slide linearly in the mold closing direction. The push block 272 and the molding channel together form the movable mold 2 cavity. The other end of the push rod 23 is fixedly connected to the push block 272. A large amount of gas will be generated and released during the plasticizing and mold compression process of the plastic, so the exhaust system is very important. The mold core of the present application adopts a through molding channel. The push block 272 that slides in the molding channel is used as the bottom surface of the movable mold 2 cavity, which can produce a good exhaust effect. The push block 272 is pushed by the push rod 23 to compress the engineering plastic, which can achieve smooth compression and avoid instability in the compression process.

[0038] The push block 272 is also provided with an exhaust groove on its side. An exhaust groove is also provided on the parting surface to further enhance the exhaust effect.

[0039] A compression stopper 28 is also fixedly mounted on the ejector plate 22. After the ejector plate 22 moves a set distance relative to the movable plate 24, the compression stopper 28 abuts against the movable plate 24 to prevent the ejector plate 22 from continuing to move relative to the movable plate 24. When designing the compression system, the compression amount and compression force should be considered to select the oil cylinder 25. The compression stopper 28 is also used to implement a hard limit on the compression to avoid unlimited compression, prevent the product from being mechanically damaged, and prevent the mold from being crushed.

[0040] The fixed mold core 13 is evenly spaced with a plurality of fixed mold cavities 311, and the movable mold core 27 is evenly spaced with a plurality of movable mold 2 cavities. The sprue 14 is located in the middle of each fixed mold cavity 311. The movable mold core 27 is also provided with a cold material well directly opposite to the sprue 14. The cold material well is located in the middle of each movable mold 2 cavity. The sprue 14 is connected to the cold material well when the mold is closed. The cold material well is connected to the gate 29 of each movable mold 2 cavity through the runner. The gate 29 is a fan-shaped structure with a width closer to one end of the movable mold 2 cavity than the width closer to one end of the runner. Both ends of the gate 29 are connected to the runner and the movable mold 2 cavity through fillets. The ejector plate 22 is also provided with a material head ejector pin 231, which can be inserted into the cold material well of the movable mold core 27 to eject the material head when the mold is opened. The gate 29 can reduce the shear force during the injection molding process by combining the fan-shaped structure with the fillet.

[0041] A mold temperature controller, a dynamic mold temperature control oil circuit and a fixed mold temperature control oil circuit are also provided. The dynamic mold oil inlet 273 of the dynamic mold temperature control oil circuit is located on the side wall of the dynamic mold core 27, and the dynamic mold oil outlet 241 of the dynamic mold temperature control oil circuit is located on the side wall of the dynamic mold plate 24. The dynamic mold plate 24 is provided with an avoidance channel directly opposite to the oil inlet on the dynamic mold core 27. The fixed mold oil inlet 132 of the fixed mold temperature control oil circuit is located on the side wall of the fixed mold core 13, and the fixed mold oil outlet 121 of the fixed mold temperature control oil circuit is located on the fixed mold plate 12. On the side wall, the fixed mold plate 12 is provided with an avoidance channel directly opposite to the oil inlet on the fixed mold core 13, the movable mold temperature control oil circuit and the fixed mold temperature control oil circuit are both connected to the mold temperature machine, and the mold temperature machine adjusts the oil temperature in the movable mold temperature control oil circuit and the fixed mold temperature control oil circuit respectively, and the oil outlet pipeline of the mold temperature machine is respectively connected to the oil inlet located on the side wall of the fixed mold core 13 and the movable mold core 27, and the oil return pipeline of the mold temperature machine is respectively connected to the oil outlet located on the side wall of the fixed mold plate 12 and the movable mold plate 24. During compression injection molding, the mold temperature needs to be adjusted according to the process. The mold oil circuit needs to be as balanced as possible. The mold core and the template both use separate oil circuits, and the distance from the mold core oil circuit to the product is designed according to actual needs. During product production, the movable mold 2 and the fixed mold 1 need to be connected to the mold temperature machine separately, and the connection of the mold temperature machine needs to enter from the mold core and exit from the template.

[0042] Both ends of the ejection plate 22 extend out to a set distance outside the space between the movable template 24 and the movable mold base 21, and through holes are respectively provided at both ends of the ejection plate 22. The cylinder bodies of the two oil cylinders are respectively fixedly installed on the two side walls of the movable template 24, and T-shaped pull rods 251 are respectively fixedly installed on the piston rods of the two oil cylinders. The rod portion of the T-shaped pull rod 251 with a small diameter can be slidably penetrated into the through hole of the ejection plate 22, and the end of the T-shaped pull rod 251 with a large size is stopped on the surface of the ejection plate 22 on the side facing away from the movable template 24.

[0043] At least two guide rods are fixedly provided on the ejector plate 22, and a guide through hole extending along the mold closing direction is provided on the movable plate 24. The guide rod on the ejector plate 22 can be slidably inserted into the guide through hole on the movable plate 24, and the ejector return spring is sleeved on the outside of the guide rod, and the two ends of the ejector return spring are respectively pressed against the surface of the ejector plate 22 and the movable plate 24. The guide rod slides in the guide through hole to guide the ejector plate.

[0044] The ejector plate 22 is also fixedly mounted with a plurality of cushions on one side facing the movable die seat 21. This prevents the ejector plate from resetting and hitting the movable die seat, thereby causing targeted damage to the entire die and also reduces noise.

[0045] A cushion block is fixedly mounted on the movable die base 21 , and the movable die plate 24 is fixedly mounted on the cushion block. The movable die base 21 , the movable die plate 24 and the cushion block together form a space for movably accommodating the ejector plate 22 .

[0046] A thrust bearing processing technology, the specific steps are as follows:

[0047] Step 1: preparing the bearing pad base 31 by machining;

[0048] Step 2: Place the processed bearing pad matrix 31 into the pressure injection molding mold for positioning, and inject molten engineering plastics with low friction coefficient and high heat resistance into the molding cavity of the pressure injection molding mold after mold closing. The engineering plastics are preferably soluble polytetrafluoroethylene (PFA) and its modified products, polyetheretherketone (PEEK) modified polymers or polyimide polymers (PAI). Under the pressure holding state, compress the size of the molding cavity in the mold closing direction to the designed size, and the engineering plastics continue to be heated and pressed in the molding cavity to solidify and mold, and finally form a wear-resistant layer 32 on the surface of the bearing pad matrix 31 to form a bearing pad blank 3;

[0049] Step 3: Fix and position the bearing pad blank 3 on the CNC machine tool, and perform CNC finishing on it according to the drawing size to form a semi-finished bearing pad;

[0050] Step 4: Grind the CNC machined semi-finished bearing pad to obtain a finished bearing pad.

[0051] The engineering plastic used to form the wear-resistant layer 32 on the surface of the bearing pad needs to have a low friction coefficient, good heat resistance and good machining performance, so that it can achieve high-precision pad size and appropriate oil film thickness, making it easy for the bearing to achieve dynamic pressure lubrication.

[0052] Soluble polytetrafluoroethylene (PFA) and its modified products have a series of excellent properties. Its friction coefficient is small, between 0.01-0.10, which is the smallest among existing plastic materials and even all engineering materials. By adding any filler that can withstand the melting temperature of PFA to PFA, the mechanical properties can be greatly improved while maintaining other excellent properties of PFA. The varieties that can be used for filling include glass fiber, metal, metallized oxide, graphite, molybdenum disulfide, carbon fiber, polyimide, EKONOL, etc. The wear resistance and the limit PV value can be increased by 1000 times. It is one of the excellent materials for making bearing pads.

[0053] Polyetheretherketone (PEEK) modified polymer plastic has high mechanical strength, high temperature resistance, impact resistance, flame retardancy, acid and alkali resistance, hydrolysis resistance, wear resistance, fatigue resistance, radiation resistance and good electrical properties. In addition, PEEK has excellent dimensional stability. Changes in environmental conditions such as temperature and humidity have little effect on the size of PEEK parts, and can meet the use requirements under conditions with relatively high dimensional accuracy. The thermal expansion coefficient is small, and the size of PEEK parts changes very little with changes in temperature (which can be caused by changes in ambient temperature or frictional heat during operation). PEEK is suitable for making high-load bearings;

[0054] Polyimide polymer (PAI) combines the performance advantages of thermosetting polyimide with the melt processing advantages of thermoplastics. PAI's wear resistance has excellent performance in both dry and lubricated environments. It can maintain its toughness, high strength and high stiffness at conditions up to 275°C (525°F), making PAI the highest performing thermoplastic in the industry. Its wide range of chemical resistance covers strong acids and most organics. PAI also has higher compressive strength and impact resistance than most advanced engineering plastics, extremely high creep resistance, and extremely low coefficient of linear thermal expansion (CLTE), giving it excellent dimensional stability. The maximum operating temperature in air is high (continuously 250°C). It maintains excellent mechanical strength, stiffness and creep resistance over a wide temperature range. It also maintains excellent dimensional stability and excellent wear resistance at up to 260°C. It is suitable for tile production under extreme working conditions.

[0055] When facing different working conditions, one of the above three materials can be selected according to the needs. These three materials can not only fully meet the use requirements of the bearing, but also meet the production conditions of the pressure injection molding process, and can also share the mold production to save costs.

[0056] In the first step, the method for preparing the bearing pad matrix 31 is selected from one of the following methods according to the needs:

[0057] (1) In the first step, the metal sheet is processed into the shape of the bearing pad blank 3 by wire cutting, and then a fixing groove for fixing the wear-resistant layer 32 is processed on its surface by CNC processing. The pad processed by the metal sheet is suitable for low-load bearings. The fixing groove processed on the surface of the metal sheet can be a dovetail groove or a T-slot, etc., which is used to achieve a firm combination of the bearing pad blank 3 and the plastic wear-resistant layer 32. During processing, the metal sheets can be stacked to improve processing efficiency and reduce processing costs, and can also greatly improve product consistency;

[0058] (2). In the first step, copper particles are sintered on the surface of the metal sheet, and then the metal sheet sintered with copper particles is processed into the shape of the bearing pad blank 3 by wire cutting. The pad with copper particles has excellent heat dissipation performance and is suitable for high-load bearings.

Claims

1. A pressure injection molding mold, characterized in that: It comprises a fixed mold (1) and a movable mold (2) capable of moving toward the fixed mold to achieve mold closing with the fixed mold, wherein: The fixed mold comprises a fixed mold base (11), a fixed mold plate (12) and a fixed mold core (13), wherein the fixed mold plate is fixedly mounted on the fixed mold base, the fixed mold core is fixedly mounted on the side of the fixed mold plate facing the movable mold, a concave fixed mold cavity (131) is formed on the surface of the fixed mold core facing the movable mold, and a sprue (14) communicating with the fixed mold cavity is provided on the fixed mold base, the fixed mold plate and the fixed mold core; The movable mold comprises a movable mold base (21), a material ejection plate (22), a push rod (23), a movable mold plate (24), an oil cylinder (25), a material ejection return spring (26) and a movable mold core (27). The movable mold plate is fixedly installed on one side of the movable mold base, and the movable mold core is fixedly installed on the movable mold plate. A concave movable mold cavity (271) is formed on the surface of the movable mold core facing the fixed movable mold. The bearing pad blank that needs to be injected with a composite wear-resistant layer can be inserted into the movable mold cavity with the side wall tightly attached. The movable mold cavity and the fixed mold cavity are directly connected to form a molding cavity when the mold is closed. The material ejection plate can be installed between the movable mold base and the movable mold plate in a linear sliding manner along the mold closing direction. The cylinder body of the oil cylinder is fixed to the movable mold base. The movable mold base is fixedly mounted on the movable mold plate, the piston rod of the oil cylinder is connected to the ejector plate and can drive the ejector plate to move toward the fixed mold cavity, the ejector return spring provides the ejector plate with an elastic return force in the direction away from the movable mold plate, one end of the ejector rod is fixedly mounted on the ejector plate, the other end of the ejector rod can be inserted into the movable mold cavity by sliding along the mold closing direction, the other end of the ejector rod can slide along the ejector plate toward the movable mold plate and push the bearing pad blank in the mold cavity to move toward the fixed mold, the movable mold base is provided with a discharge channel for the ejector rod (4) on the injection molding machine to pass through, the ejector rod on the injection molding machine can prevent the ejector plate from moving synchronously with the movable mold base in the direction away from the fixed mold.

2. The pressure injection molding mold according to claim 1, characterized in that: The movable mold core is provided with a molding channel penetrating along the mold closing direction, a push block (272) is inserted into the molding channel of the movable mold core so as to be able to slide linearly along the mold closing direction, the push block and the molding channel together form a movable mold cavity, and the other end of the push rod is fixedly connected to the push block.

3. The pressure injection molding mold according to claim 2, characterized in that: An exhaust groove is also arranged on the side of the push block.

4. The pressure injection molding mold according to claim 1, characterized in that: The ejector plate is also fixedly mounted with a compression limit block (28), which, after the ejector plate moves a set distance relative to the movable template, abuts against the movable template to prevent the ejector plate from continuing to move relative to the movable template.

5. The pressure injection molding mold according to claim 1, characterized in that: The fixed mold core is provided with a plurality of fixed mold cavities at even intervals, and the movable mold core is provided with a plurality of movable mold cavities at even intervals. The sprue is located in the middle of each fixed mold cavity. The movable mold core is also provided with a cold material well directly opposite to the sprue. The cold material well is located in the middle of each movable mold cavity. The sprue is connected to the cold material well when the mold is closed. The cold material well is connected to the gate (29) of each movable mold cavity through the runner. The gate is a fan-shaped structure with a width closer to one end of the movable mold cavity than that closer to one end of the runner. Both ends of the gate are connected to the runner and the movable mold cavity through rounded corners. A material head ejector pin (231) is also provided on the ejector plate. The material head ejector pin can be inserted into the cold material well of the movable mold core to eject the material head when the mold is opened.

6. The pressure injection molding mold according to claim 1, characterized in that: A mold temperature controller, a movable mold temperature control oil circuit and a fixed mold temperature control oil circuit are also provided. The movable mold oil inlet (273) of the movable mold temperature control oil circuit is located on the side wall of the movable mold core, the movable mold oil outlet (241) of the movable mold temperature control oil circuit is located on the side wall of the movable mold plate, the movable mold plate is provided with an avoidance channel directly facing the oil inlet on the movable mold core, the fixed mold oil inlet (132) of the fixed mold temperature control oil circuit is located on the side wall of the fixed mold core, and the fixed mold oil outlet (121) of the fixed mold temperature control oil circuit is located on the side wall of the fixed mold core. On the side wall of the fixed mold plate, the fixed mold plate is provided with an avoidance channel directly opposite to the oil inlet on the fixed mold core, the movable mold temperature regulating oil circuit and the fixed mold temperature regulating oil circuit are both connected with the mold temperature controller, and the mold temperature controller respectively adjusts the oil temperature in the movable mold temperature regulating oil circuit and the fixed mold temperature regulating oil circuit, the oil outlet pipeline of the mold temperature controller is respectively connected with the oil inlets located on the side walls of the fixed mold core and the movable mold core, and the oil return pipeline of the mold temperature controller is respectively connected with the oil outlets located on the side walls of the fixed mold plate and the movable mold plate.

7. The pressure injection molding mold according to claim 1, characterized in that: The two ends of the ejector plate extend out to a set distance outside the space between the movable template and the ejector base, and through holes are respectively provided at the two ends of the ejector plate. The cylinder bodies of the two oil cylinders are respectively fixedly installed on the two side walls of the movable template, and T-shaped pull rods (251) are respectively fixedly installed on the piston rods of the two oil cylinders. The rod portion of the T-shaped pull rod with a small diameter can be slidably inserted into the through hole of the ejector plate, and the end portion of the T-shaped pull rod with a large size is stopped on the surface of the ejector plate on the side facing away from the movable template.

8. The pressure injection molding mold according to claim 1, characterized in that: At least two guide rods are fixedly provided on the ejection plate, and the movable template is provided with guide through holes extending along the mold closing direction. The guide rods on the ejection plate can be slidably inserted into the guide through holes on the movable template, and the ejection return spring is sleeved on the outside of the guide rods, and both ends of the ejection return spring are respectively tightly pressed against the ejection plate and the surface of the movable template.

9. The pressure injection molding mold according to claim 1, characterized in that: A plurality of buffer pads are fixedly mounted on the side of the ejector plate facing the movable die seat.

10. The pressure injection molding mold according to claim 1, characterized in that: A cushion block is fixedly mounted on the movable die seat, and the movable die plate is fixedly mounted on the cushion block. The movable die seat, the movable die plate and the cushion block together form a space for movably accommodating the ejector plate.

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