Automobile multi-vee belt forming die and forming process thereof

Abstract

This invention belongs to the field of molding die technology, and particularly relates to a multi-wedge belt molding die for automobiles and its molding process. The molding die includes an outer mold cylinder, an inner mold core, an elastic sleeve, a switching component, a pressure sensor, and a control unit. The outer mold cylinder is provided with a wedge groove and a first boss, and is equipped with a heating unit and a cooling unit. The elastic sleeve is sleeved on the outside of the inner mold core, forming a pressure chamber between the two. The switching component is located inside the inner mold core, connecting the supply unit and the pressure chamber, and can automatically switch the pressure charging and depressurization paths according to the pressure of the pressure medium. The pressure sensor collects the pressure signal of the pressure chamber, and the control unit adjusts the output pressure of the supply unit in a closed loop. By repeatedly alternating the charging and depressurization mode of the pressure chamber, and with the single charging pressure increment being greater than the depressurization pressure reduction, the pressure chamber is pressurized in a stepwise manner, avoiding single pressurization, reducing defects such as missing material and air bubbles in the wedge teeth, and ensuring the dimensional accuracy and consistency of the multi-wedge belt product.

Description

Technical Field

[0001] This invention belongs to the field of molding die technology, and in particular relates to an automotive multi-wedge belt molding die and its molding process. Background Technology

[0002] Automotive multi-ribbed belts are friction transmission components of the engine front accessory drive system. They generally use EPDM rubber as the base material, with polyester or aramid tensile cords embedded inside, and multiple 40° trapezoidal wedge teeth distributed on the inner side.

[0003] Traditional automotive multi-wedge belts typically use vulcanization followed by grinding to process the wedge teeth. This process not only generates grinding waste and results in poor wedge tooth accuracy and consistency, but also easily leads to deviations in tooth shape and pitch, affecting transmission performance and service life.

[0004] Therefore, some automotive multi-ribbed belts currently use compression molding. This process uses high-precision molding dies to directly form wedge teeth during the vulcanization of the belt blank, eliminating the grinding process, reducing material loss, and relying on the dies to ensure the accuracy and consistency of the wedge teeth, thus improving the processing quality. However, traditional compression molding usually uses single-stage pressure application, which can easily lead to uneven pressure distribution, resulting in filling defects in the wedge teeth and affecting the stability of multi-ribbed belt product performance. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned technical problems by providing an automotive multi-wedge belt molding die and its molding process. This process achieves multiple pressure applications and gradual molding, avoiding uneven distribution of rubber material pressure that could lead to wedge tooth defects and thus prevent affecting product performance stability.

[0006] In view of this, the present invention provides an automotive multi-wedge belt forming mold, comprising: The outer mold cylinder has multiple axially distributed wedge-shaped grooves and a first boss for supporting the strip blank on its inner wall, and is connected to a heating unit and a cooling unit. The inner mold core is arranged coaxially with the outer mold cylinder and can slide axially. It is used to move into or out of the outer mold cylinder, and when it enters the outer mold cylinder, a sealed molding cavity is formed between the two. An elastic sleeve is fitted onto the surface of the inner mold core, forming a pressure cavity between the sleeve and the surface of the inner mold core. The pressure cavity is connected to a supply unit for supplying pressure medium. The switching component is installed inside the inner mold core, connecting the supply unit and the pressure chamber, and automatically switching the pressure medium to fill the pressure chamber or drain from the pressure chamber in response to pressure changes of the pressure medium output by the supply unit. A pressure sensor, mounted on the surface of the inner mold core, is used to detect and provide feedback on the pressure signal within the pressure chamber; The control unit, electrically connected to the supply unit and the pressure sensor, is used to receive feedback from the pressure sensor to adjust the pressure of the pressure medium output by the supply unit. During the pressurization of the pressure chamber, the pressure medium is alternately injected and discharged into the pressure chamber in multiple cycles. In each cycle, the pressure increase caused by the injection is greater than the pressure decrease caused by the discharge.

[0007] In the above technical solution, the switching component further includes: The connecting cylinder is installed inside the inner mold core, and one end is connected to the supply unit; The housing is installed at the end of the connecting cylinder away from the supply unit, with one end connected to the connecting cylinder and the other end connected to the pressure chamber via a guide pipe. A second protrusion is formed on the inner wall near the connecting cylinder. Pressure relief pipe, installed on the housing, is used to connect the inside and outside of the housing; The core is slidably assembled inside the housing and coaxially arranged with the connecting cylinder, and a first spring is installed on the side away from the connecting cylinder to push the core against the second protrusion; The core responds to pressure changes in the pressure medium output by the supply unit, automatically switching between the conductive pipe and the pressure relief pipe or between the core and the connecting cylinder.

[0008] In the above technical solution, further: The core has an annular flow channel on its surface and a connecting flow channel inside; A bypass pipe is provided on the side of the housing, and both ends of the bypass pipe are connected to the inside of the housing; Specifically, when the pressure medium output by the supply unit exerts a force greater than the elastic restoring force of the first spring on the core, the conducting pipe is connected to the connecting cylinder through the annular flow channel and the bypass pipe; when the pressure medium output by the supply unit exerts a force less than the elastic restoring force of the first spring, the conducting pipe is connected to the pressure relief pipe through the annular flow channel and the connecting flow channel.

[0009] In the above technical solution, further: Multiple conductive tubes are provided and are evenly distributed along the circumference of the shell; The connecting channel includes an outlet connected to the annular channel and multiple inlets connected to multiple guide pipes respectively.

[0010] In the above technical solution, the switching component further includes: The valve body is installed at the end of the pressure relief pipe away from the housing, and has a through port that connects to the pressure relief pipe; The opening and closing element is installed in the valve body and is used to control the opening and closing of the conduction port; An adjusting element, installed on the side of the opening and closing element away from the pressure relief pipe, is used to adjust the pressure relief threshold of the pressure relief pipe; The valve body has a discharge port on its side.

[0011] In the above technical solution, the opening and closing components further include: The valve core, installed inside the valve body, is used to control the opening and closing of the conduction port; The second spring is installed inside the valve body, with its two ends abutting against the valve core and the inner wall of the valve body, respectively.

[0012] In the above technical solution, the adjusting component further includes: The guide tube is installed on the valve body, with one end extending into the valve body and slidingly sealing with the valve core, and the other end extending out of the valve body and having a connecting pipe that connects to the end of the housing near the connecting tube.

[0013] In the above technical solution, further: The end of the shell away from the connecting cylinder is an opening, and a cover is installed on the opening; The cover has a through hole, and an elastic airbag is installed at the through hole. The interior of the elastic airbag is connected to the interior of the housing near the first spring.

[0014] In the above technical solution, further: The outer mold cylinder has a heat exchange chamber inside, and the heat exchange chamber is connected to a first inlet pipe, a second inlet pipe, a first outlet pipe and a second outlet pipe. The first inlet pipe and the first outlet pipe are connected to the heating unit, and the second inlet pipe and the second outlet pipe are connected to the cooling unit. The first inlet tube is higher than the second inlet tube, the first outlet tube is lower than the second outlet tube, and valves are provided on the first inlet tube, the second inlet tube, the first outlet tube, and the second outlet tube.

[0015] This invention provides a molding process for an automotive multi-ribbed belt molding die, comprising the following steps: S1: The formed strip blank is placed inside the outer mold cylinder and supported by the first boss; S2: The inner mold core moves into the outer mold cylinder, the heating unit heats the outer mold cylinder, and the pressure chamber is pressurized through the supply unit; S3: The pressure medium is repeatedly and alternately filled and discharged into the pressure chamber. In each cycle, the pressure increase caused by filling into the pressure chamber is greater than the pressure decrease caused by discharging into the pressure chamber, causing the pressure inside the pressure chamber to gradually increase. S4: When the outer mold cylinder reaches the preset heating temperature and the pressure chamber reaches the preset pressure, the pressure medium supplied by the supply unit is maintained to perform pressure-holding vulcanization in the pressure chamber. S5: After the pressure holding time is preset, the cooling unit cools the outer mold cylinder until the preset cooling temperature is reached; S6: Reduce the pressure of the pressure medium supplied by the supply unit to depressurize the pressure chamber until the depressurization is completed. Then, remove the inner mold core from the outer mold cylinder, remove the molded multi-wedge strip from the outer mold cylinder, and repeat S1-S6.

[0016] The beneficial effects of this invention are as follows: 1. By setting a switching component between the supply unit and the pressure chamber, the pressure medium can be switched between being filled or drained during pressurization of the pressure chamber. This avoids uneven pressure distribution that may occur with a single pressurization, reduces the possibility of filling defects in the wedge teeth, and ensures the stable performance of multi-wedge belt products. During a single cycle of filling and draining the pressure medium, the pressure increase caused by filling the pressure chamber is greater than the pressure decrease caused by draining, thus ensuring a stable pressure rise within the pressure chamber. The pressure sensor can easily obtain the pressure value within the pressure chamber in a timely manner, allowing the control unit to adjust the pressure of the pressure medium output from the supply unit, and then adjust the switching component to switch between filling or draining the pressure medium in the pressure chamber in a timely manner, ensuring the stability of the pressure chamber.

[0017] 2. The connecting cylinder facilitates the connection between the housing and the supply unit. The sliding core then switches between the two systems. In conjunction with the first spring, when the pressure of the pressure medium supplied by the supply unit is greater than the return elastic force of the first spring, the core will slide, connecting the pressure chamber with the connecting cylinder for pressurization. When the pressure of the pressure medium supplied by the supply unit is less than the return elastic force of the first spring, the core will close the bypass pipe under the action of the spring, connecting the pressure chamber with the pressure relief pipe for pressure relief. In other words, the switching component can be controlled by simply adjusting the pressure of the pressure medium supplied by the supply unit, thus switching the pressure medium to be filled into or discharged from the pressure chamber.

[0018] 3. By setting up opening and closing components and regulating components, during pressure relief, the pressure of the pressure medium supplied by the supply unit is adjusted through the regulating components to regulate the pressure relief threshold of the pressure relief pipe, thereby achieving a pressure difference on both sides of the opening and closing components to relieve pressure in the pressure chamber. After the pressure difference disappears, the pressure relief pipe can be automatically closed by the opening and closing components to avoid excessive pressure relief, which would affect the gradual rise of pressure in the pressure chamber. This ensures that the pressure increase caused by filling the pressure chamber is always greater than the pressure decrease caused by venting. Similarly, only the pressure of the pressure medium supplied by the supply unit needs to be adjusted to control the opening and closing components and regulating components, ensuring pressure control of the pressure chamber. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a top view of the present invention; Figure 3 This is the present invention. Figure 2Sectional view at point AA; Figure 4 This is the present invention. Figure 3 Enlarged view of point B in the middle; Figure 5 This is the present invention. Figure 3 Enlarged view of point C in the middle; Figure 6 This is an exploded view of the switching component of the present invention; The markings in the diagram represent: 1. Outer mold cylinder; 2. Wedge groove; 3. First boss; 4. Inner mold core; 5. Molding cavity; 6. Elastic sleeve; 7. Pressure cavity; 8. Switching assembly; 80. Connecting cylinder; 81. Shell; 82. Conductor pipe; 83. Second boss; 84. Pressure relief pipe; 85. Core; 850. Annular flow channel; 851. Connecting flow channel; 852. Bypass pipe; 853. Outlet; 854. Inlet 86. First spring; 87. Valve body; 870. Conductor port; 871. Discharge port; 88. Opening and closing element; 880. Valve core; 881. Second spring; 89. Adjusting element; 890. Guide tube; 891. Connecting pipe; 9. Cover; 10. Through hole; 11. Elastic air bladder; 12. Heat exchange chamber; 13. First inlet pipe; 14. Second inlet pipe; 15. First outlet pipe; 16. Second outlet pipe. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0021] Example 1:

[0022] This embodiment provides an automotive multi-wedge belt forming mold, including: The outer mold cylinder 1 has multiple axially distributed wedge-shaped grooves 2 and a first boss 3 for supporting the strip blank on its inner wall, and is connected to a heating unit and a cooling unit. The inner mold core 4 is arranged coaxially with the outer mold cylinder 1 and can slide along the axial direction. It is used to move into or out of the outer mold cylinder 1, and when it enters the outer mold cylinder 1, a sealed molding cavity 5 is formed between the two. The elastic sleeve 6 is fitted onto the surface of the inner mold core 4, and a pressure cavity 7 is formed between the elastic sleeve 6 and the surface of the inner mold core 4. The pressure cavity 7 is connected to a supply unit for supplying pressure medium. The switching component 8 is installed inside the inner mold core 4, connecting the supply unit and the pressure chamber 7, and responding to the pressure change of the pressure medium output by the supply unit, automatically switching the pressure medium to fill the pressure chamber 7 or to drain from the pressure chamber 7. A pressure sensor is installed on the surface of the inner mold core 4 to detect and provide feedback on the pressure signal inside the pressure chamber 7; The control unit, electrically connected to the supply unit and the pressure sensor, is used to receive feedback from the pressure sensor to adjust the pressure of the pressure medium output by the supply unit. During the pressurization of pressure chamber 7, the pressure medium is alternately injected into and discharged into pressure chamber 7 in multiple cycles. In each cycle, the pressure increase caused by the injection into pressure chamber 7 is greater than the pressure decrease caused by the discharge. It should be noted that the heating unit can be a steam generator, the cooling unit can be a compressor, radiator and circulating pump, etc., and the lifting of the inner mold core 4 can be driven by a push rod, cylinder and other devices. The elastic sleeve 6 is made of rubber and is a pre-vulcanized product. The pressure sensor, control unit and valve for opening and closing are all conventional structures of traditional compression molding dies, which are known to those skilled in the art from traditional compression molding dies, and will not be described in detail here. Meanwhile, sealing rings are provided between the two axial ends of the outer mold cylinder 1 and the inner mold core 4. Conventional technical means to achieve a sealed molding cavity 5 are not described here. Furthermore, the supply unit can be composed of an air compressor and a pressure regulating valve, that is, pressurizing the pressure chamber 7 to fill the pressure chamber 7 with high-pressure gas, which is a conventional pressurization device in the art, and will not be described in detail here.

[0023] As can be seen from this embodiment, by setting a switching component 8 between the supply unit and the pressure chamber 7, the pressure medium can be switched between filling or releasing when pressurizing the pressure chamber 7. Compared with the traditional single static pressurization mode, this effectively avoids the problems of uneven pressure distribution, excessive or insufficient local pressure that are easy to occur with single pressurization, reduces molding defects such as incomplete filling of multi-wedge belt wedge teeth, material shortage, and air bubbles, and effectively ensures the dimensional accuracy and stable performance of multi-wedge belt products. By limiting the pressurization increment in a single cycle to be greater than the depressurization reduction, the overall pressure of pressure chamber 7 is stabilized and increased. At the same time, the pressure sensor collects the pressure signal inside the chamber in real time and feeds it back to the control unit. The control unit can accurately adjust the output pressure of the supply unit and link the switching component 8 to complete the adjustment of pressurization and depressurization, ensuring the stability and accuracy of the pressure in pressure chamber 7. In addition, the first boss 3 inside the outer mold cylinder 1 can stably support the placed strip blank and prevent it from slipping after being loaded; while the inner wall is provided with 100-150 wedge grooves 2, which can complete the molding of multiple wedge strips at one time. Afterwards, it only needs to be cut according to the product specifications, which greatly improves the mold production efficiency and adapts to the needs of mass industrial production.

[0024] Example 2:

[0025] This embodiment provides an automotive multi-wedge belt forming mold, which, in addition to the technical solutions of the above embodiments, also has the following technical features, wherein the switching component 8 includes: The connecting cylinder 80 is installed inside the inner mold core 4, and one end is connected to the supply unit; The housing 81 is installed at the end of the connecting cylinder 80 away from the supply unit, and one end is connected to the connecting cylinder 80. The other end is provided with a guide pipe 82 connected to the pressure chamber 7, and a second protrusion 83 is formed on the inner wall near the connecting cylinder 80. Pressure relief pipe 84 is installed on housing 81 and is used to connect the inside and outside of housing 81; The core 85 is slidably assembled inside the housing 81 and is coaxially arranged with the connecting cylinder 80. A first spring 86 is installed on the side away from the connecting cylinder 80 to push the core 85 against the second protrusion 83. Among them, the core 85 responds to the pressure change of the pressure medium output by the supply unit and automatically switches the connection between the conductor 82 and the pressure relief pipe 84 or the connection cylinder 80. Meanwhile, the pressure relief pipe 84 can be connected to the exhaust pipe or can be left open. That is, the inner mold core 4 is located in the non-sealed installation chamber of the switching component 8. When the pressure relief pipe 84 releases high-pressure air gas, it can be discharged directly. A sealing ring can be fitted onto the core 85, which not only ensures the sealing performance between the core 85 and the housing 81, but also provides a certain frictional resistance for the movement of the core 85, that is, to prevent the core 85 from jumping under the drive of the first spring 86 to reset, and to ensure the stable movement of the core 85.

[0026] As can be seen from this embodiment, the stable connection between the shell 81 and the supply unit is achieved through the connecting cylinder 80, establishing a stable pressure medium delivery channel. Relying on the elastic cooperation between the axially sliding core 85 inside the shell 81 and the first spring 86, a pressure adaptive switching structure is formed. By adjusting the pressure of the pressure medium output by the supply unit, the magnitude of the thrust of the medium pressure on the core 85 can be changed, overcoming or cooperating with the elastic restoring force of the first spring 86, and automatically completing the switching of the passage between the conducting pipe 82 and the connecting cylinder 80 and the pressure relief pipe 84. No additional electrically controlled valves are required, and the structure is simple. Furthermore, the second protrusion 83 can precisely limit the maximum sliding position of the core 85, and together with the sealing gasket at the second protrusion 83, it can effectively improve the sealing performance when the core 85 abuts against the second protrusion 83. The first spring 86 remains compressed, continuously providing a reset thrust to the core 85, ensuring accurate and precise reset of the core 85. Meanwhile, the sealing ring on the outside of the core 85 not only ensures the sealing of the internal cavity of the housing 81, but also increases the damping of the sliding of the core 85, preventing the core 85 from jumping or shifting during high-speed sliding and reset, greatly improving the stability and repeatability of the switching component 8 and extending the service life of the component.

[0027] Example 3:

[0028] This embodiment provides an automotive multi-wedge belt forming mold, which, in addition to the technical solutions of the above embodiments, also has the following technical features: The core 85 has an annular flow channel 850 on its surface and a connecting flow channel 851 inside its interior; A bypass pipe 852 is provided on the side of the housing 81, and both ends of the bypass pipe 852 are connected to the inside of the housing 81; When the pressure medium output by the supply unit exerts a force on the core 85 greater than the elastic restoring force of the first spring 86, the conducting pipe 82 is connected to the connecting cylinder 80 through the annular flow channel 850 and the bypass pipe 852. When the pressure medium output by the supply unit exerts a force on the core 85 less than the elastic restoring force of the first spring 86, the conducting pipe 82 is connected to the pressure relief pipe 84 through the annular flow channel 850 and the connecting flow channel 851. Furthermore, the connection between the guide tube 82 and the pressure chamber 7 can be achieved by fitting a disc body onto the connecting cylinder 80, with a chamber inside the disc body corresponding to the guide tube 82, and the chamber having a first circular hole along the axial direction to connect with the guide tube 82, while the side of the chamber that is radially away from the axis is open, and a second circular hole is formed on the inner wall of the inner mold core for connecting the pressure chamber 7 and the chamber.

[0029] As can be seen from this embodiment, by setting an annular flow channel 850 on the surface of the core 85 and a connecting flow channel 851 inside, and in conjunction with the bypass pipe 852 on the outside of the shell 81, a dual-channel structure for pressurization and depressurization that is independent and can be quickly switched is constructed. When the system is pressurized, the medium can smoothly enter the pressure chamber 7 through the connecting cylinder 80, bypass pipe 852, annular flow channel 850, and connecting pipe 82, forming a complete and stable pressurization path. When the system is depressurized, the medium in the pressure chamber 7 can be quickly discharged through the connecting pipe 82, connecting flow channel 851, annular flow channel 850, and depressurization pipe 84, forming a smooth depressurization path. The path switching can be completed by the axial sliding of the core 85 alone, and the switching structure is simple. Meanwhile, the use of a disc body with axial and radial circular holes enables the connection between the guide tube 82 and the pressure chamber 7. This not only strengthens the structural strength of the connecting cylinder 80 through the disc body, but also improves the overall installation stability and structural rigidity of the switching component 8, reducing the possibility of deformation and loosening of the components after long-term lifting and lowering of the inner mold core 4. Furthermore, the double circular hole conduction structure ensures the smooth transmission of the pressure medium. Combined with the flexible metal hose-type guide tube 82, which can be flexibly adapted for installation, the assembly difficulty is reduced and the overall assembly convenience of the mold is improved.

[0030] Example 4:

[0031] This embodiment provides an automotive multi-wedge belt forming mold, which, in addition to the technical solutions of the above embodiments, also has the following technical features: Multiple conductive tubes 82 are provided and are distributed at equal intervals along the circumference of the housing 81; The connecting channel 851 includes an outlet 853 connected to the annular channel 850 and multiple inlets 854 respectively connected to multiple guide pipes 82; It should be noted that multiple guide tubes 82 are provided. In order to ensure that the multiple inlets 854 on the connecting channel 851 always correspond to the guide tubes 82, the core 85 needs to be equipped with a limiting component to ensure that the core 85 only slides axially and does not rotate radially. Therefore, a guide post is provided on the side of the core 85 away from the connecting cylinder 80, and a guide cylinder is provided on the inner wall of the housing 81. A groove is opened on the surface of the guide post, and the inner wall of the guide cylinder is adapted to the groove. This is a conventional limiting structure. In addition to this method, other limiting components can also be used, as long as they can restrict the core 85 to slide axially and not rotate radially. These will not be elaborated here.

[0032] As can be seen from this embodiment, by arranging multiple conductive pipes 82 at equal intervals along the circumference of the shell 81, and in conjunction with the structure of multiple inlets 854 in the connecting channel 851, the pressure medium can be uniformly filled into and discharged from the pressure chamber 7 in the circumference, avoiding the problems of uneven local pressure and large local deformation differences of the elastic sleeve 6 that may exist in single-pipe pressurization and depressurization; the uniform air-filling structure can ensure that the elastic sleeve 6 expands synchronously and uniformly as a whole, so that the extrusion pressure of the elastic sleeve 6 on the strip blank is consistent, and the filling and vulcanization of the wedge teeth at each position of the multi-wedge strip are uniform, thereby improving the overall forming accuracy and product consistency of the multi-wedge strip; Meanwhile, the limiting structure that matches the guide post and guide cylinder can restrict the radial rotation of the core 85, ensuring that the multiple inlets 854 of the connecting channel 851 are always precisely aligned with each guide tube 82, avoiding problems such as misalignment, blockage, and uneven pressure relief, ensuring the accuracy and stability of pressure switching, further improving molding quality, and reducing product defect rate.

[0033] Example 5:

[0034] This embodiment provides an automotive multi-wedge belt forming mold, which, in addition to the technical solutions of the above embodiments, also has the following technical features. The switching component 8 further includes: The valve body 87 is installed at the end of the pressure relief pipe 84 away from the housing 81, and has a through port 870 that communicates with the pressure relief pipe 84; The opening and closing element 88 is installed inside the valve body 87 and is used to control the opening and closing of the guide port 870; Adjusting element 89 is installed on the side of opening and closing element 88 away from pressure relief pipe 84, and is used to adjust the pressure relief threshold of pressure relief pipe 84; The valve body 87 has a discharge port 871 on its side.

[0035] As can be seen from this embodiment, by adding a valve body 87 structure to the end of the pressure relief pipe 84, setting an opening and closing component 88 to control the opening and closing of the pressure relief passage, and adjusting component 89 to precisely regulate the pressure relief threshold, the pressure relief process can be finely controlled. When the mold is working, the medium pressure of the supply unit can be adjusted to form a stable pressure difference on both sides of the opening and closing part 88, triggering the pressure relief action. When the pressure is relieved until the pressure difference on both sides disappears, the opening and closing part 88 automatically resets and closes the pressure relief passage, effectively avoiding excessive pressure relief, ensuring that the pressure increase in a single cycle is greater than the pressure reduction, ensuring that the pressure in the pressure chamber 7 rises continuously and steadily in a step-like manner, and avoiding excessive pressure fluctuations that would affect the vulcanization molding effect. The entire pressure relief control process does not require the assistance of an independent control system. It can achieve adaptive opening and closing and threshold adjustment through the pressure difference of the pressure medium itself. It has strong structural linkage and high control precision. The discharge port 871 on the side of the valve body 87 can quickly and smoothly discharge the pressure relief medium, avoid the medium from accumulating in the valve body 87, ensure the pressure relief passage is unobstructed, and further improve the stability of pressure control.

[0036] Example 6:

[0037] This embodiment provides an automotive multi-wedge belt forming mold, which, in addition to the technical solutions of the above embodiments, also has the following technical features, wherein the opening and closing component 88 includes: Valve core 880 is installed inside valve body 87 and is used to control the opening and closing of conduction port 870; The second spring 881 is installed inside the valve body 87, and its two ends abut against the valve core 880 and the inner wall of the valve body 87, respectively. To ensure sealing performance, a sealing gasket is provided on the side of the valve core 880 near the pressure relief pipe 84.

[0038] As can be seen from this embodiment, by adopting the elastic opening and closing structure of valve core 880 and second spring 881, the structure is simple, the response is fast, and the durability is strong. It can achieve adaptive opening and closing through the pressure difference on both sides of valve core 880, without the need for additional drive structures such as electromagnetic or pneumatic, thus reducing the mold manufacturing cost. For example, when the pressure in pressure chamber 7 is too high, the pressure of the pressure medium supplied by the supply unit is reduced to enhance pressure relief. Conversely, when the pressure in pressure chamber 7 is too low, the pressure of the pressure medium supplied by the supply unit is increased to stop pressure relief and repressurize, thus accurately adapting to the process requirements of the step-by-step pressure increase of pressure chamber 7. The sealing gasket at the end of the valve core 880 can significantly improve the sealing performance after the guide port 870 is closed, avoiding the problem of medium leakage and pressure loss after the pressure relief passage is closed, and ensuring the pressure stabilization effect of the pressure chamber 7. This structure can control the start and stop of pressure relief and the pressure relief amplitude by simply adjusting the output pressure of the supply unit, which is convenient to operate and has a good control effect.

[0039] Example 7:

[0040] This embodiment provides an automotive multi-wedge belt forming mold, which, in addition to the technical solutions of the above embodiments, also has the following technical features: the adjusting member 89 includes: The guide tube 890 is installed on the valve body 87, with one end extending into the valve body 87 and slidingly sealing with the valve core 880, and the other end extending out of the valve body 87 and having a connecting pipe 891 that communicates with the end of the housing 81 near the connecting tube 80. The sliding seal between the guide cylinder 890 and the valve core 880 is achieved by fitting a sealing ring on the surface of the valve core 880, which is a conventional structure and will not be described in detail here.

[0041] As can be seen from this embodiment, the pressure medium of the supply unit is accurately introduced into the valve core 880 away from the pressure relief pipe 84 through the guide tube 890, so that the valve core 880 bears the output pressure of the supply unit on one side and the internal pressure of the pressure chamber 7 on the other side, forming a bidirectional symmetrical pressure force structure, which can accurately build a stable and controllable pressure difference and provide a precise power source for the opening and closing of the valve core 880. By adjusting the output pressure of the supply unit, the force on one side of the valve core 880 can be directly changed, and the pressure relief opening threshold can be precisely adjusted to achieve fine control of the pressure relief amplitude and timing, adapting to different pressure requirements. This adjustment structure only needs to lead out a branch pipe from the housing 81 to complete the passage connection. The overall structure is simple and compact, without the need to add complex control components, effectively simplifying the overall structure of the mold and reducing processing and assembly costs. Meanwhile, the sliding sealing structure between the valve core 880 and the guide cylinder 890 can prevent media leakage, ensure the accuracy and stability of the pressure difference, further improve the pressure control precision, and ensure the long-term stable operation of the mold.

[0042] Example 8:

[0043] This embodiment provides an automotive multi-wedge belt forming mold, which, in addition to the technical solutions of the above embodiments, also has the following technical features: The end of the housing 81 away from the connecting cylinder 80 is open, and a cover 9 is installed on the opening; The cover 9 has a through hole 10, and an elastic airbag 11 is installed in the through hole 10. The interior of the elastic airbag 11 is connected to the interior of the housing 81 on the side near the first spring 86. Meanwhile, since the rotation of the core 85 is restricted by the setting of the limiting component, a vent hole is opened on the limiting component, such as on the inner wall of the guide cylinder, to ensure that when the core 85 compresses the internal space of the housing 81, the air pressure can enter the elastic airbag 11 through the vent hole.

[0044] As can be seen from this embodiment, by setting a cap 9 at the opening end of the housing 81 and combining it with an elastic airbag 11 structure, and with the ventilation holes on the inner wall of the guide cylinder, the adaptive adjustment of the air pressure in the internal chamber of the housing 81 can be achieved. When the core 85 slides axially to compress the internal space of the housing 81, the air in the chamber can be discharged into the elastic airbag 11 through the vent hole. The elastic deformation of the elastic airbag 11 buffers the chamber pressure, greatly reducing the air pressure resistance of the core 85 sliding, ensuring that the core 85 slides smoothly and without jamming throughout the process, and improving the response speed and accuracy of pressure switching. Therefore, the combination of the cap 9 and the elastic airbag 11 can achieve complete sealing of the internal cavity of the housing 81, effectively preventing external dust, oil, and impurities from entering the housing 81, avoiding problems such as core 85 jamming and sealing failure, effectively protecting the precision structure of the switching component 8, extending the service life of the core components of the mold, and reducing equipment maintenance costs and downtime failure rate.

[0045] Example 9:

[0046] This embodiment provides an automotive multi-wedge belt forming mold, which, in addition to the technical solutions of the above embodiments, also has the following technical features: The outer mold cylinder 1 has a heat exchange chamber 12 inside, and the heat exchange chamber 12 is connected to a first inlet pipe 13, a second inlet pipe 14, a first outlet pipe 15 and a second outlet pipe 16. The first inlet pipe 13 and the first outlet pipe 15 are connected to the heating unit, and the second inlet pipe 14 and the second outlet pipe 16 are connected to the cooling unit. The first inlet tube 13 is higher than the second inlet tube 14, the first outlet tube 15 is lower than the second outlet tube 16, and valves are provided on the first inlet tube 13, the second inlet tube 14, the first outlet tube 15 and the second outlet tube 16. Meanwhile, solenoid valves can be used.

[0047] As can be seen from this embodiment, by opening a heat exchange chamber 12 inside the outer mold cylinder 1, and by introducing and exporting steam and cooling water through the first inlet pipe 13, the second inlet pipe 14, the first outlet pipe 15, and the second outlet pipe 16, and by setting valves to control the opening and closing of all of them, when steam needs to be introduced, the first inlet pipe 13 and the first outlet pipe 15 are opened, and the second inlet pipe 14 and the second outlet pipe 16 are closed; when cooling water needs to be introduced, the second inlet pipe 14 and the second outlet pipe 16 are opened, and the first inlet pipe 13 and the second outlet pipe 16 are closed. The control is convenient and it is easy to switch between heating and cooling. Meanwhile, the heat exchange medium uses conventional heat exchange media such as steam and cooling water, which can be directly used in the same heat exchange chamber 12, resulting in a simple structure and low cost.

[0048] Example 10:

[0049] This embodiment provides a molding process for an automotive multi-ribbed belt molding die, including the following steps: S1: The formed strip blank is placed inside the outer mold cylinder 1 and supported by the first boss 3; S2: The inner mold core 4 is moved into the outer mold cylinder 1, the heating unit heats the outer mold cylinder 1, and the pressure chamber 7 is pressurized through the supply unit; S3: The pressure medium is repeatedly and alternately filled into and discharged into the pressure chamber 7. In each cycle, the pressure increase caused by filling into the pressure chamber 7 is greater than the pressure decrease caused by discharging, so that the pressure inside the pressure chamber 7 gradually increases. S4: When the outer mold cylinder 1 reaches the preset heating temperature and the pressure chamber 7 reaches the preset pressure, the pressure medium supplied by the supply unit is maintained to perform pressure-holding vulcanization in the pressure chamber 7. S5: After the pressure holding time is preset, the cooling unit cools the outer mold cylinder 1 until the preset cooling temperature is reached; S6: Reduce the pressure of the pressure medium supplied by the supply unit to depressurize the pressure chamber 7 until the depressurization is completed. Then, remove the inner mold core 4 from the outer mold cylinder 1, remove the molded multi-wedge strip from the outer mold cylinder 1, and repeat S1-S6.

[0050] As can be seen from this embodiment, by performing multiple cycles of pressure filling and depressurization during pressurization, and with the pressure increment in the pressure chamber 7 being greater than the pressure reduction, the elastic sleeve 6 repeatedly squeezes and releases the strip blank, and each squeeze is stronger than the previous one. This allows the strip blank to gradually conform to the wedge groove 2 to complete the filling and vulcanization, effectively avoiding the problems of uneven pressure distribution, excessive or insufficient local pressure that are easy to occur with single pressure application. It also reduces molding defects such as incomplete filling of the wedge teeth, material shortage, and air bubbles in multi-wedge strips, effectively ensuring the dimensional accuracy and stable performance of multi-wedge strip products. After heating and vulcanization, the multi-wedge strip is cooled and shaped to ensure a fixed product shape and prevent deformation or springback after molding. At the same time, the overall process is simple and easy to operate, which can quickly realize continuous production in a cyclical manner, resulting in high production efficiency, good product consistency, and effectively reducing the product defect rate.

[0051] The embodiments of this application have been described above with reference to the accompanying drawings. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A multi-wedge belt forming mold for automobiles, characterized in that, include: The outer mold cylinder (1) has multiple axially distributed wedge-shaped grooves (2) and a first boss (3) for supporting the strip blank on its inner wall, and is connected to a heating unit and a cooling unit. The inner mold core (4) is arranged coaxially with the outer mold cylinder (1) and can slide along the axial direction. It is used to move into or out of the outer mold cylinder (1), and when it enters the outer mold cylinder (1), a sealed molding cavity (5) is formed between the two. An elastic sleeve (6) is fitted onto the surface of the inner mold core (4) and forms a pressure cavity (7) between it and the surface of the inner mold core (4). The pressure cavity (7) is connected to a supply unit for supplying pressure medium. The switching component (8) is installed inside the inner mold core (4), connecting the supply unit and the pressure chamber (7), and automatically switching the pressure medium to fill the pressure chamber (7) or drain from the pressure chamber (7) in response to the pressure change of the pressure medium output by the supply unit. A pressure sensor is installed on the surface of the inner mold core (4) to detect and provide feedback on the pressure signal inside the pressure chamber (7); The control unit, electrically connected to the supply unit and the pressure sensor, is used to receive feedback from the pressure sensor to adjust the pressure of the pressure medium output by the supply unit. When the pressure chamber (7) is pressurized, the pressure medium is alternately injected into and discharged into the pressure chamber (7) in multiple cycles. In each cycle, the pressure increase caused by the injection into the pressure chamber (7) is greater than the pressure decrease caused by the discharge.

2. The automotive multi-wedge belt forming mold according to claim 1, characterized in that, The switching component (8) includes: The connecting cylinder (80) is installed inside the inner mold core (4), and one end is connected to the supply unit; The housing (81) is installed at the end of the connecting cylinder (80) away from the supply unit, and one end is connected to the connecting cylinder (80), while the other end is provided with a guide pipe (82) connected to the pressure chamber (7), and a second protrusion (83) is formed on the inner wall near the connecting cylinder (80). A pressure relief pipe (84) is installed on the housing (81) to connect the inside and outside of the housing (81); The core (85) is slidably assembled inside the housing (81) and coaxially arranged with the connecting cylinder (80), and a first spring (86) is installed on the side away from the connecting cylinder (80) to push the core (85) against the second boss (83). The core (85) responds to the pressure change of the pressure medium output by the supply unit and automatically switches the connection between the conductor (82) and the pressure relief pipe (84) or the connection between the conductor (80) and the connecting cylinder (80).

3. The automotive multi-wedge belt forming mold according to claim 2, characterized in that: The core (85) has an annular flow channel (850) on its surface and a connecting flow channel (851) inside its interior. The side of the housing (81) is provided with a bypass pipe (852), and both ends of the bypass pipe (852) are connected to the inside of the housing (81); When the pressure medium output by the supply unit exerts a force on the core (85) greater than the elastic restoring force of the first spring (86), the connecting pipe (82) is connected to the connecting cylinder (80) through the annular flow channel (850) and the bypass pipe (852). When the pressure medium output by the supply unit exerts a force on the core (85) less than the elastic restoring force of the first spring (86), the connecting pipe (82) is connected to the pressure relief pipe (84) through the annular flow channel (850) and the connecting flow channel (851).

4. The automotive multi-wedge belt forming mold according to claim 3, characterized in that: Multiple conductive tubes (82) are provided and are distributed at equal intervals along the circumference of the shell (81); The connecting channel (851) includes an outlet (853) connected to the annular channel (850) and multiple inlets (854) respectively connected to multiple guide pipes (82).

5. The automotive multi-wedge belt forming mold according to claim 2, characterized in that, The switching component (8) further includes: The valve body (87) is installed at the end of the pressure relief pipe (84) away from the housing (81) and has a through port (860) connected to the pressure relief pipe (84); An opening and closing element (88) is installed inside the valve body (87) and is used to control the opening and closing of the guide port (860); An adjusting element (89) is installed on the side of the opening and closing element (88) away from the pressure relief pipe (84) to adjust the pressure relief threshold of the pressure relief pipe (84); The valve body (87) has a discharge port (861) on its side.

6. The automotive multi-wedge belt forming mold according to claim 5, characterized in that, The opening and closing element (88) includes: The valve core (880) is installed inside the valve body (87) and is used to control the opening and closing of the guide port (860); The second spring (881) is installed inside the valve body (87), and its two ends abut against the valve core (880) and the inner wall of the valve body (87) respectively.

7. The automotive multi-wedge belt forming mold according to claim 6, characterized in that, The adjusting member (89) includes: The guide tube (890) is installed on the valve body (87), with one end extending into the valve body (87) and slidingly sealing with the valve core (880), and the other end extending out of the valve body (87) and having a connecting pipe (891) connected to the end of the housing (81) near the connecting tube (80).

8. The automotive multi-wedge belt forming mold according to claim 2, characterized in that: The end of the housing (81) away from the connecting cylinder (80) is open, and a cover (9) is installed on the opening. The cover (9) has a through hole (10) and an elastic airbag (11) is installed in the through hole (10). The interior of the elastic airbag (11) is connected to the interior of the shell (81) on the side near the first spring (86).

9. The automotive multi-wedge belt forming mold according to claim 1, characterized in that: The outer mold cylinder (1) has a heat exchange chamber (12) inside, and the heat exchange chamber (12) is connected to a first inlet pipe (13), a second inlet pipe (14), a first outlet pipe (15), and a second outlet pipe (16). The first inlet pipe (13) and the first outlet pipe (15) are connected to the heating unit, and the second inlet pipe (14) and the second outlet pipe (16) are connected to the cooling unit. The first inlet tube (13) is higher than the second inlet tube (14), the first outlet tube (15) is lower than the second outlet tube (16), and valves are provided on the first inlet tube (13), the second inlet tube (14), the first outlet tube (15), and the second outlet tube (16).

10. A molding process applied to the automotive multi-ribbed belt forming mold according to any one of claims 1-9, characterized in that, Includes the following steps: S1: The formed strip blank is placed inside the outer mold cylinder (1) and supported by the first boss (3); S2: The inner mold core (4) is moved into the outer mold cylinder (1), the heating unit heats the outer mold cylinder (1), and the pressure chamber (7) is pressurized by the supply unit; S3: The pressure medium is repeatedly injected into and discharged into the pressure chamber (7) in alternating cycles. In each alternating cycle, the pressure increase caused by the injection into the pressure chamber (7) is greater than the pressure decrease caused by the discharge, so that the pressure inside the pressure chamber (7) gradually increases. S4: When the outer mold cylinder (1) reaches the preset heating temperature and the pressure chamber (7) reaches the preset pressure, the pressure medium supplied by the supply unit is maintained to perform pressure-holding vulcanization on the pressure chamber (7); S5: After the pressure holding time is preset, the cooling unit cools the outer mold cylinder (1) until the preset cooling temperature is reached; S6: Reduce the pressure of the pressure medium supplied by the supply unit to depressurize the pressure chamber (7) until the depressurization is completed. Then, the inner mold core (4) is removed from the outer mold cylinder (1), the multi-wedge strip is removed from the outer mold cylinder (1), and S1-S6 are repeated.

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