A mold for producing a seal

Abstract

The application provides a preparation mold of a seal, the preparation mold comprises an upper mold and a lower mold, at least one of the upper mold and the lower mold is provided with at least one gas storage groove; the upper mold is provided with a first forming surface, the lower mold is provided with a second forming surface matched with the first forming surface, and the first forming surface and the second forming surface constitute at least part of a seal forming cavity, and the notch of the gas storage groove is located on the first forming surface or the second forming surface. The preparation mold can improve the forming yield of the seal.

Description

Technical Field

[0001] This application relates to the field of mold technology, specifically to a mold for preparing a seal. Background Technology

[0002] Seals are typically made of rubber, and their sealing function usually relies on the elasticity of the rubber. However, in some applications, such as valves, moving parts may slide relative to the seal. Due to the high resistance of the rubber, this can hinder the smooth movement of the moving parts. To reduce the resistance between the rubber and the seal, a patch with a relatively low coefficient of friction is placed on one side of the seal. This patch is then bonded together using a vulcanization process. Ensuring a good bond between the patch and the rubber is a crucial technical challenge that needs to be addressed. Utility Model Content

[0003] The purpose of this application is to provide a mold for preparing a seal, which helps to improve the molding yield of the seal.

[0004] This application provides a mold for preparing a seal, including an upper mold and a lower mold, wherein at least one of the upper mold and the lower mold is provided with at least one air storage groove; the upper mold has a first forming surface, and the lower mold has a second forming surface that mates with the first forming surface, wherein the first forming surface and the second forming surface constitute at least a portion of the seal forming cavity, and the opening of the air storage groove is located on the first forming surface or the second forming surface.

[0005] The mold is equipped with a gas storage tank, which is connected to the mold cavity between the gas storage tank and the first and second molding surfaces. During the vulcanization process of the rubber material entering the mold cavity, gas will be generated under high temperature and high pressure conditions. Some of the gas generated during the vulcanization process can enter the gas storage tank for storage, thereby increasing the gas storage tank as a gas holding space. This reduces the amount of gas remaining inside the final sealing product, thereby improving the physical properties of the product and increasing the molding yield of the sealing product. Attached Figure Description

[0006] Figure 1 This is a schematic diagram of the structure of the mold for preparing the seal in one embodiment of this application;

[0007] Figure 2 for Figure 1 Another structural schematic diagram of the mold preparation process;

[0008] Figure 3 for Figure 2 Schematic cross-section along the AA direction;

[0009] Figure 4 for Figure 3 Top view of the second upper and lower sub-molds after they are assembled;

[0010] Figure 5 for Figure 4 Schematic sectional view along the BB direction;

[0011] Figure 6 for Figure 5 A schematic diagram of the structure of the second upper sub-mold of the middle upper mold;

[0012] Figure 7 for Figure 6 Another structural diagram of the second upper sub-mold of the middle upper mold;

[0013] Figure 8 for Figure 5 Schematic diagram of the middle and lower mold;

[0014] Figure 9 for Figure 3 A schematic diagram of the first upper and lower sub-molds fitting together.

[0015] The annotations in the attached figures are explained as follows:

[0016] 100 - Preparation mold; 100a - First chamber; 100b - Second chamber;

[0017] 11-Upper mold; 111-First upper sub-mold; 112-Second upper sub-mold; 1121-First molding surface; 11211-First protrusion; 112a-Injection channel; 112a1-Injection port; 112a2-Inlet; 112b-First air reservoir; 112b1-First groove; 112c-Cavity;

[0018] 12-Lower mold; 121-Base; 122-Arch-shaped part; 1221-Second forming surface; 12211-Second protrusion; 12a-Second air storage groove; 12a1-Second slot. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Please refer to Figures 1 to 3 , Figure 1 This is a schematic diagram of the structure of the mold 100 for preparing the seal in one embodiment of this application; Figure 2 for Figure 1 Another structural schematic diagram of the mold 100 prepared in the middle; Figure 3 for Figure 2 A cross-sectional view along the AA direction.

[0021] The mold 100 for preparing the seal in this embodiment can be used to prepare the seal. Specifically, the seal is arc-shaped and includes an elastic portion 22 and a smooth portion. The mold 100 includes an upper mold 11 and a lower mold 12. The upper mold 11 and lower mold 12 are closed to form a mold cavity, which includes... Figure 3 The diagram shows a first chamber 100a and a second chamber 100b. The second chamber 100b is used for feeding the adhesive material, and the first chamber 100a is used for molding the sealant. The upper mold 11 includes a first molding surface 1121, and the lower mold 12 includes a second molding surface 1221. The first molding surface 1121 at least partially constitutes at least a portion of the upper wall surface of the first chamber 100a, and the second molding surface 1221 at least partially constitutes at least a portion of the lower wall surface of the first chamber 100a. That is, the first molding surface 1121 and the second molding surface 1221 constitute at least a portion of the sealant molding cavity.

[0022] In this embodiment, the first chamber 100a extends in an arched shape. Specifically, a portion of the first molding surface 1121 is recessed upward and inward. Correspondingly, the lower mold 12 includes a base 121 and an arched portion 122 protruding from the base 121, that is, a portion of the second molding surface 1221 protrudes upward and outward. After the upper mold 11 and the lower mold 12 are closed, at least a portion of the second molding surface 1221 can be accommodated in the space formed by the recess of the first molding surface 1121. At this time, there is a gap between the protruding second molding surface 1221 and the first molding surface 1121. The space formed by this gap constitutes the first chamber 100a. The adhesive can be injected into the first chamber 100a. During the filling process of the adhesive, the heated and softened adhesive flows into the first chamber 100a and is shaped. The shaped structure will also undergo post-processing to form a seal. Therefore, the shaped structure can be defined as a preform of the seal. Because the first chamber 100a extends in an arch shape, the preform of the formed seal is also roughly arc-shaped. The arc-shaped seal can better match or fit with cylindrical or similar cylindrical moving parts, which helps to improve the sealing effect of the seal.

[0023] Can be combined Figure 4 and Figure 5 understand, Figure 6 for Figure 3 Top view of the second upper sub-mold 112 and lower mold 12 after they are assembled; Figure 5 for Figure 4 A cross-sectional view along the BB direction.

[0024] In this embodiment, the upper mold 11 specifically includes a first upper sub-mold 111 and a second upper sub-mold 112. The first upper sub-mold 111 and the second upper sub-mold 112 are closed to form the aforementioned second chamber 100b. The second upper sub-mold 112 may be provided with a groove 112c, into which a portion of the first upper sub-mold 111 can be inserted to form the second chamber 100b. The first upper sub-mold 111, the second upper sub-mold 112, and the lower mold 12 are arranged sequentially from top to bottom. The second upper sub-mold 112 and the lower mold 12 cooperate. The second upper sub-mold 112 is provided with a first forming surface 1121, and the lower mold 12 is provided with a second forming surface 1221. Figure 3 As shown, the second upper sub-mold 112 is provided with a glue injection channel 112a, and the second chamber 100b is used to contain the glue. The glue injection channel 112a has a glue inlet 112a2 and a glue injection port 112a1. The glue inlet 112a2 is connected to the second chamber 100b, and the glue injection port 112a1 is located on the first molding surface 1121, thus connecting to the first chamber 100a. The glue can flow into the first chamber 100a through the glue injection channel 112a for vulcanization molding. The upper mold 11 is divided into a first upper sub-mold 111 and a second upper sub-mold 112, which facilitates the feeding of glue into the preparation mold 100. It can be seen that the upper mold 11 can also be an integral structure.

[0025] Please combine again Figures 6 to 8 As shown, Figure 6 for Figure 5 A schematic diagram of the structure of the second upper sub-mold 112 of the upper middle mold 11; Figure 7 for Figure 6 Another structural diagram of the second upper sub-mold of the middle upper mold, having four first protrusions 1121, Figure 6 It has four first protrusions 1121; Figure 8 for Figure 5 A schematic diagram of the structure of the lower middle mold 12.

[0026] In this embodiment, at least one of the upper mold 11 and the lower mold 12 is provided with at least one air storage tank, and the air storage tank can be... Figure 5 The blind hole structure shown is specifically a straight blind hole structure extending vertically. The air storage groove can also be inclined relative to the vertical direction, or it can be a groove structure of other shapes. In this embodiment, both the second upper sub-mold 112 and the lower mold 12 of the upper mold 11 are provided with air storage grooves, which are respectively defined as the first air storage groove 112b and the second air storage groove 12a. The groove opening of the air storage groove is located on the first forming surface 1121 or the second forming surface 1221, and the rest of the air storage groove is closed. The air storage groove can communicate with the first chamber 100a through its groove opening. Figures 6 to 8 In the first gas storage tank 112b, the opening is the first opening 112b1, and the opening of the second gas storage tank 12a is the second opening 12a1.

[0027] During the vulcanization process of the rubber compound entering the first chamber 100a, gas will be generated under high temperature and high pressure. Since the preparation mold 100 in this embodiment is equipped with a gas storage tank that is connected to the first chamber 100a, some of the gas generated during the vulcanization process can enter the gas storage tank for storage. That is, the gas storage tank is increased as a gas holding space, thereby reducing the gas remaining inside the final sealing product. This is beneficial for the elastic part 22 and the smooth part to be well molded after bonding, thereby improving the physical properties of the product and increasing the molding yield of the sealing part.

[0028] In addition, the sealing element is specifically the sealing element of the valve device. The sealing element is located between the valve body and the valve core of the valve device. When the valve core rotates along the axis, it can open or close the valve body channel opened on the valve body. The sealing element has a corresponding connecting hole with the valve body channel.

[0029] At this time, as Figures 6 to 8 As shown, the first molding surface 1121 includes a plurality of protruding first protrusions 11211, which are spaced apart. The second molding surface 1221 includes a plurality of protruding second protrusions 12211, which are spaced apart. After mold closing, the first protrusions 11211 and the second protrusions 12211 are positioned opposite each other. "Positioned opposite each other" means that the end faces of the first protrusions 11211 and the second protrusions 12211 are directly opposite each other. When the upper mold 11 and the lower mold 12 are closed, there is a gap between the first protrusions 11211 and the second protrusions 12211. When the adhesive enters the first chamber 100a, a portion of the adhesive will fill the gap between the first protrusion 11211 and the second protrusion 12211. After the adhesive has cured and set, this gap area forms a cutting area with a thickness less than the adjacent area. That is, the preform of the seal includes the cutting area. The cutting area is cut off after being processed by the cutting equipment to form the connecting hole of the seal. The cutting area is the part of the preform that will be cut off.

[0030] In some embodiments, at least part of the opening of the gas storage tank may be located at the first protrusion 11211 and / or the second protrusion 12211, such as Figures 6 to 8 As shown, the first slot 112b1 is located at the first protrusion 11211, and the second slot 12a1 is located at the second protrusion 12211. In this way, the air storage groove corresponds to at least a partial location of the preform of the seal to be cut, the preform to be cut will be cut, and the air storage groove will not affect the performance of the seal.

[0031] It can be seen that when the first protrusion 11211 is provided with the first gas storage tank 112b, the first opening 112b1 of the first gas storage tank 112b faces downward. When the rubber material is filled in the first chamber 100a and during the vulcanization process, gas can enter the first gas storage tank 112b. The rubber material rarely or never enters the first gas storage tank 112b. The first gas storage tank 112b is mainly used to store gas. When the second protrusion 12211 is provided with the second gas storage tank 12a, the second opening 12a1 of the second gas storage tank 12a faces upward. When the rubber material is filled in the first chamber 100a and during the vulcanization process, gas can enter the second gas storage tank 12a. The rubber material may also enter the second gas storage tank 12a. However, the radial dimension of the second gas storage tank 12a can be set to be relatively small in order to minimize or avoid the rubber material entering the second gas storage tank 12a, so as to ensure the space for storing gas. Furthermore, as mentioned above, the first air storage groove 112b and the second air storage groove 12a can be provided in the corresponding first protrusion 11211 or second protrusion 12211. Even if the adhesive enters the first air storage groove 112b or the second air storage groove 12a, the portion of adhesive, after being shaped, will be connected to the preform's cutting area and can be removed during the cutting process, thus not affecting the performance of the seal.

[0032] like Figure 7 and Figure 8 As shown, in some embodiments, the opening of the gas storage tank may be located in the middle of the first protrusion 11211 and / or the second protrusion 12211. This facilitates the relatively uniform exhaust of gas within the first chamber 100a.

[0033] like Figure 9 As shown, Figure 9 for Figure 3 A schematic diagram of the engagement of the first upper sub-mold 111 and the lower mold 12.

[0034] In this embodiment, at least one of the upper mold 11 and the lower mold 12 may be provided with at least one injection channel 112a. The injection channels 11a may all be located in the upper mold 11 to improve injection efficiency by utilizing gravity. Of course, both the upper mold 11 and the lower mold 12 may also be provided with injection channels 112a. The injection channel 112a has an injection port 112a1. The injection channel 112a may have one injection port 112a2 and one or more injection ports 112a1, i.e., two or more. Figure 9 The injection channel 112a shown in the diagram has one injection port 112a2 and two injection ports 112a1. The multiple injection ports 112a1 are located at different positions on the first molding surface 1121 or the second molding surface 1221.

[0035] The upper mold 10 includes a concave arched surface, and the first molding surface 1121 also includes an arched surface. The midpoint of the highest point of the arched surface can be defined as the structural center of the arched surface. Multiple injection ports 112a1 are symmetrically arranged relative to the structural center of the arched surface. For example, three injection ports 112a1 are included: one injection port 112a1 is located at the highest point of the arched surface, and two other injection ports 112a1 are located on the extension line of the arched surface passing through this injection port 112a1. The other two injection ports 112a1 are symmetrically arranged relative to this injection port 112a1. In one specific embodiment, the three injection ports 112a1 can be respectively located at three first protrusions 11211. In subsequent cutting processes, the residual glue portion corresponding to the injection port 112a1, along with a portion of the glue material, is removed.

[0036] For example, a mold for preparing a seal with three injection ports 112a1 can be used to prepare a seal with connecting holes spaced apart along the length of the seal. Furthermore, a mold for preparing a seal with all three injection ports 112a1 located at the first protrusion 11211 is suitable for preparing a seal with an odd number of connecting holes, such as a seven-hole seal or a nine-hole seal. It can also be used for seals with an even number of connecting holes; there is no particular limitation in this regard.

[0037] For example, there are eight injection ports 112a1. Four injection ports 112a1 are set near the structural center of the arched surface. These four injection ports 112a1 are symmetrically arranged around the structural center. The other four injection ports 112a1 are respectively set at the four first protrusions 11211 closest to the structural center. It can also be understood that the four first protrusions 11211 are symmetrically arranged around the structural center. The preparation mold 100 with eight injection ports 112a1 is suitable for preparing seals with connecting holes arranged in double rows along the length of the seal. The number of connecting holes is generally even, such as a six-hole seal or an eight-hole seal. Of course, it can also be used for seals with an odd number of connecting holes. There is no special limitation on this. By setting 112a1 injection ports symmetrically arranged relative to the center of the structure, and with the injection ports 112a1 positioned close to the center of the structure, the injection channel 113 of the injection port 112a1 closest to the highest point is the shortest. The heated and molten adhesive first flows out from one or several injection ports 112a1 corresponding to the highest point, and then flows out from the remaining injection ports 112a1. This helps to fill the first chamber 100a more evenly with adhesive, and also helps to avoid wrinkles in the prefabricated part caused by the impact at the highest point. Therefore, the special setting of the injection ports 112a1 helps to improve the yield of the seal.

[0038] In some embodiments, at least a portion of the injection port 112a1 may be located on the first protrusion 11211 and / or the second protrusion 12211. In this case, the injection port 112a1 and the opening of the air storage tank are staggered, that is, the injection port 112a1 and the air storage tank do not interfere with each other and are not directly connected. For example, the first protrusion 11211 or the second protrusion 12211 may be provided with both the injection port 112a1 and the air storage tank; alternatively, a portion of the protrusion may be provided with the air storage tank, and another portion of the protrusion may be provided with the injection port 112a1; alternatively, at least a portion of the air storage tank may be located outside the protrusion, and at least a portion of the injection port 112a1 may be located on the protrusion, or at least a portion of the injection port 112a1 may be located outside the protrusion, and at least a portion of the air storage tank may be located on the protrusion.

[0039] In some embodiments, the cross-sectional area of ​​the second protrusion 12211 from the root to the end can gradually decrease. The term "gradually" here is not limited to a fixed ratio of reduction. As long as it conforms to the trend from large to small, it is within the scope of protection of this application. In this embodiment, the peripheral sidewall of the second protrusion 12211 is a slope. The special arrangement of the second protrusion 12211 helps the preform to form a transition portion on the peripheral sidewall of the second protrusion 12211. The presence of the transition portion makes it less likely for the moving part to rub against the seal, causing the seal to twist or the moving part to jam.

[0040] As an example, the cross-sectional area of ​​the first protrusion 11211 from the root to the end can be the same, that is, the peripheral sidewall of the first protrusion 11211 is a straight surface. In the subsequent cutting process, the peripheral sidewall of the recess formed by the first protrusion 11211 can be used to position the cutting tool and ensure the accuracy of the position of the connecting hole of the seal.

[0041] This embodiment also provides a method for preparing a seal, wherein a preform of the seal is processed using the preparation mold 100 described in any of the above embodiments. The specific process is as follows:

[0042] S1. Material feeding:

[0043] The material cutting includes the cutting of rubber material. In this embodiment, the sealing part prepared by the mold 100 includes a smooth part and an elastic part 22. The elastic part 22 and the smooth part are vulcanized together in the mold 100. Therefore, the material cutting in this embodiment also includes the cutting of the smooth part.

[0044] Smooth part material preparation: The smooth part is, for example, a PTFE (Polytetrafluoroethylene) film. The prepared PTFE film can be placed on the second forming surface 1221 of the lower mold 12, and the smooth part is fixed and flattened in the first cavity 100a by closing the second sub-upper mold 11, with the inner surface of the smooth part adhering to the second forming surface 1221;

[0045] Rubber material feeding: The prepared rubber material is injected into the first chamber 100a through the injection channel 112a. Specifically, the rubber material can be placed into the groove 112c of the second upper mold 112, and the first upper mold 111 is closed to form a second chamber 100b for accommodating the rubber material. The rubber material can enter the first chamber 100a from the second chamber 100b through the injection channel 112a. The rubber material can be EPDM (Ethylene Propylene Diene Monomer) raw material.

[0046] S2. Vulcanization: The preparation mold 100 is controlled to vulcanize the rubber compound under the first environmental parameters. The first environmental parameters include parameters such as temperature and pressure, which can be determined according to the actual needs of the molded product. For example, in this embodiment, if the preparation mold 100 needs to vulcanize the elastic part 22 of the seal, the temperature of the upper mold 11 and the lower mold 12 can be controlled at 190±10°, the vulcanization pressure can be controlled at, for example, 15±5MPa, and the vulcanization time can be 220±20s.

[0047] Based on the design of the mold 100, the vulcanized structure can be further processed to form a preform. The preform can then undergo edge trimming and other treatments. Specifically, the surface burrs of the preform can be trimmed using a machine tool.

[0048] Depending on product requirements, the precast parts after edge trimming can be further processed, such as undergoing two-stage vulcanization. They can be placed in a constant temperature oven under second environmental parameters to enhance structural performance. The second environmental parameters can also be parameters such as temperature and pressure.

[0049] After secondary vulcanization, the product can be inspected and controlled before leaving the factory. The inspection and control can specifically include testing the water resistance to ethylene glycol, peel strength, etc.

[0050] In this embodiment, during the vulcanization process, the mold 100 can undergo a vulcanization venting operation, which can be performed at least once. Specifically, the venting operation involves moving the upper mold 11 and lower mold 12 in the opposite direction to the mold closing direction, i.e., moving them along the mold opening direction, separating the upper mold 11 and lower mold 12. For example, the upper mold 11 can be raised a certain distance, creating a certain communication gap between the first chamber 100a and the outside, thus facilitating gas discharge. The venting operation can expel a portion of the gas, and at least a portion of the remaining gas can enter the aforementioned gas storage tank, further reducing the amount of gas remaining in the product. The venting operation can be performed more than once, for example, in a 2+2 venting mode: venting twice after mold closing, and then venting twice again after a certain interval (e.g., 25±5s) after injection, such as venting twice before the injection is complete but not yet cured. The venting time can be set according to actual needs, for example, 25±5s.

[0051] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A mold for preparing a sealing element, characterized in that, The device includes an upper mold (11) and a lower mold (12), at least one of the upper mold (11) and the lower mold (12) being provided with at least one air storage groove; the upper mold (11) has a first forming surface (1121), and the lower mold (12) has a second forming surface (1221) that mates with the first forming surface (1121); the first forming surface (1121) and the second forming surface (1221) constitute at least a portion of the sealing component forming cavity; the opening of the air storage groove is located on the first forming surface (1121) or the second forming surface (1221).

2. The mold for preparing the seal according to claim 1, characterized in that, The first molding surface (1121) partially protrudes toward the second molding surface (1221) to form a first protrusion (11211), and the second molding surface (1221) partially protrudes toward the first molding surface (1121) to form a second protrusion (12211); after the mold is closed, there is a gap between the first protrusion (11211) and the second protrusion (12211); The opening of the gas storage tank is located at the first protrusion (11211) and / or the second protrusion (12211).

3. The mold for preparing the seal according to claim 2, characterized in that, The opening of the gas storage tank is located in the middle of the first protrusion (11211) and / or the second protrusion (12211).

4. The mold for preparing the seal according to claim 2 or 3, characterized in that, At least one of the upper mold (11) and the lower mold (12) is provided with at least one injection channel (112a), the injection channel (112a) having at least one injection port (112a1); at least a portion of the injection port (112a1) is located at the first protrusion (11211) and / or the second protrusion (12211), and the injection port (112a1) and the opening of the gas storage tank are staggered.

5. The mold for preparing the seal according to any one of claims 1-3, characterized in that, At least one of the upper mold (11) and the lower mold (12) is provided with at least one injection channel (112a), and the injection channel (112a) has at least one injection port (112a1).

6. The mold for preparing the seal according to claim 5, characterized in that, The upper mold (11) includes a first upper sub-mold (111) and a second upper sub-mold (112). The second upper sub-mold (112) is provided with the first molding surface (1121) and the injection channel (112a). The second upper sub-mold (112) and the lower mold (12) are closed to form a first chamber (100a). The first upper sub-mold (111) and the second upper sub-mold (112) are closed to form a second chamber (100b). The second chamber (100b) is used to contain the adhesive material. The injection channel (112a) has an inlet (112a2) which connects the first chamber (100a) and the second chamber (100b).

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