A method and mold for hot press forming of rubber gaskets

Abstract

The application relates to the technical field of hot-press forming, and discloses a hot-press forming method and a mold for rubber gaskets, wherein the middle part of the upper end of a base is provided with a cylindrical seat for placing a lower mold assembly; when rubber gasket forming raw materials are poured into a forming cavity through an injection hole, air in the forming cavity is discharged through an exhaust pipeline system; after the upper mold assembly is moved upward and reset, the upper mold assembly and the lower mold assembly are separated, at the same time, flat springs are used to move the lower mold assembly upward and reset, so that the hot-press formed rubber gasket is ejected. The air in the forming cavity is discharged through the exhaust pipeline system, which is beneficial to the rubber gasket forming raw materials to fill the forming cavity; after the upper mold assembly is moved upward and reset, the upper mold assembly and the lower mold assembly can be automatically separated, which is convenient for subsequent ejection of the rubber gasket, at the same time, the flat springs are used to move the lower mold assembly upward and reset, so that the hot-press formed rubber gasket is ejected, which is convenient for taking down the rubber gasket.

Description

Technical Field

[0001] This invention relates to the field of hot pressing molding technology, specifically to a method and mold for hot pressing molding of rubber gaskets. Background Technology

[0002] The hot pressing process for rubber gaskets is primarily based on the thermoplasticity and pressure molding principles of rubber materials. Under heating conditions, the rubber material becomes soft and possesses a certain degree of fluidity, at which point it can be compressed into the desired shape by applying pressure. After cooling, the rubber material solidifies and retains its molded shape and dimensions. Before hot pressing, if there is still air in the molding cavity formed after the upper and lower molds are closed, the flowable rubber material cannot fill the molding cavity, resulting in defects in the molded rubber gasket. Furthermore, after hot pressing, the upper and lower molds must be manually disassembled to remove the rubber gasket. Since the molding cavity is generally located inside the upper and lower molds, even after disassembly, it is still inconvenient to remove the rubber gasket from the molding cavity. Therefore, we have introduced a hot pressing method and mold for rubber gaskets. Summary of the Invention

[0003] The purpose of this invention is to provide a method and mold for hot pressing rubber gaskets to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A hot-press molding die for rubber gaskets includes a base, wherein a cylindrical seat for placing a lower mold assembly is provided at the upper middle part of the base.

[0006] The upper two sides of the base are also provided with buffer cylinder assemblies that are connected to the upper mold assembly;

[0007] The lower platform at the top inner side of the cylindrical seat is provided with a limiting arc groove that matches the bottom of the lower mold assembly, and a heating wire is added inside the limiting arc groove;

[0008] The connecting columns on the left and right sides of the lower end of the lower mold assembly extend into the hollow cavity inside the cylindrical seat and are connected to an annular lifting seat. A flat spring is connected to the bottom of the annular lifting seat, and an annular airbag connected to the buffer cylinder assembly is also provided at the top of the annular lifting seat.

[0009] When the upper mold assembly descends, the buffer cylinder assembly not only buffers the upper mold assembly, but also injects air into the annular airbag, causing the annular airbag to expand and drive the lower mold assembly to move down until the upper mold assembly is in close contact with the top of the lower mold assembly, thus forming a sealed molding cavity between the upper mold assembly and the lower mold assembly.

[0010] The lower mold assembly is equipped with an exhaust pipe system. When the rubber gasket molding material is injected into the molding cavity through the injection hole on the upper mold assembly, the air in the molding cavity is discharged through the exhaust pipe system.

[0011] After the lower mold assembly moves down to the top of the inner side of the cylindrical seat, the heating wire is used to heat and keep the rubber gasket molding material in the molding cavity warm;

[0012] After the upper mold assembly moves upward and resets, the upper mold assembly and the lower mold assembly are separated. At the same time, the flat spring is used to move the lower mold assembly upward and reset, thereby pushing out the rubber gasket after hot pressing.

[0013] Preferably, the top outer side of the cylindrical seat is provided with an annular limiting protrusion;

[0014] The lower mold assembly includes an annular lower mold base and an inner platform and an outer platform integrally formed and connected to the inner and outer sides of the top of the annular lower mold base;

[0015] The inner and outer platforms have the same thickness, and the outer diameter of the outer platform is the same as the inner diameter of the annular limiting protrusion.

[0016] The connecting columns on the left and right sides are symmetrically connected to the middle of the lower end of the outer platform, and the connecting columns pass through the openings on the limiting arc groove.

[0017] Preferably, the buffer cylinder assembly includes a buffer cylinder body fixed on both sides of the upper end of the base, a cylinder piston disposed inside the buffer cylinder body, and a piston rod connected to the middle of the upper end of the cylinder piston, and the bottom of the buffer cylinder body is connected to the corresponding annular airbag by an air guide pipe.

[0018] Preferably, the upper mold assembly includes a top seat, a columnar seat connected to the lower end of the top seat, and an annular upper mold seat fixed to the lower end of the columnar seat;

[0019] The top seat is symmetrically provided with connecting ears on its side, and the top of the piston rod extends through the buffer cylinder and connects to the bottom of the corresponding connecting ear.

[0020] Preferably, the annular upper mold base has a semi-circular upper mold cavity at the lower middle part, and the annular lower mold base has a semi-circular lower mold cavity at the upper middle part. After the annular upper mold base and the annular lower mold base are closed, the molding cavity is composed of the semi-circular upper mold cavity and the semi-circular lower mold cavity.

[0021] The bottom of the injection hole passes through the top seat, the columnar seat and the annular upper mold seat in sequence and extends to the top of the semi-circular upper mold cavity.

[0022] Preferably, the exhaust pipe system includes several sets of channels evenly spaced inside the inner platform and a collection tank connected by a bend after the inner end of the channel extends to the inner wall of the inner platform.

[0023] Preferably, the inner end of the bent tube is first inclined upward and then downward to form a bend before extending into the collection tank. After the annular upper mold base and the annular lower mold base are closed, the height of the bend in the bent tube is higher than the top of the semi-circular upper mold cavity. The top of the collection tank is provided with an exhaust hole.

[0024] The present invention also provides a molding method for a hot pressing mold for rubber gaskets, specifically including the following steps:

[0025] S1. The upper mold assembly descends, and the buffer cylinder assembly buffers the upper mold assembly. At the same time, the buffer cylinder assembly injects air into the annular airbag, causing the annular airbag to expand and drive the lower mold assembly to move down. The upper mold assembly is pressed against the top of the lower mold assembly, so that the upper mold assembly and the lower mold assembly move down synchronously until the lower mold assembly sits on the top of the inner side of the cylindrical seat, so that a sealed molding cavity is formed between the upper mold assembly and the lower mold assembly.

[0026] S2. When the rubber gasket molding material is injected into the molding cavity through the injection hole on the upper mold assembly, the air in the molding cavity is discharged through the exhaust pipe system. At the same time, the heating wire heats and keeps the rubber gasket molding material in the molding cavity warm.

[0027] S3. After the rubber gasket is formed by hot pressing of the raw material in the molding cavity, the upper mold assembly moves upward and resets, and the upper mold assembly and the lower mold assembly separate. At the same time, the flat spring pushes the lower mold assembly to move upward and reset, thereby pushing the rubber gasket out.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: When the upper mold assembly descends, the buffer cylinder assembly acts as a buffer for the upper mold assembly, while the annular airbag expands and drives the lower mold assembly to move downward until the upper mold assembly is tightly attached to the top of the lower mold assembly, thus forming a sealed molding cavity between the upper and lower mold assemblies; the lower mold assembly is provided with an exhaust pipe system inside, and when the rubber gasket molding material is injected into the molding cavity through the injection hole on the upper mold assembly, the air in the molding cavity is discharged through the exhaust pipe system, which helps the rubber gasket molding material to fill the molding cavity; after the upper mold assembly moves upward and resets, the upper mold assembly and the lower mold assembly can be automatically separated, which facilitates the subsequent demolding of the rubber gasket. At the same time, the flat spring is used to move the lower mold assembly upward and reset, thereby pushing out the hot-pressed rubber gasket, which makes it easy to remove the rubber gasket. Attached Figure Description

[0029] Figure 1 This is a three-dimensional structural diagram of the invention in its initial state;

[0030] Figure 2 This is a schematic diagram of the structure of the cylindrical seat and the lower mold assembly in the initial state of the present invention;

[0031] Figure 3This is a three-dimensional structural diagram showing the connection between the lower mold assembly and the exhaust pipe system of the present invention;

[0032] Figure 4 For the present invention Figure 3 A schematic diagram of the cross-sectional structure;

[0033] Figure 5 For the present invention Figure 1 A schematic diagram of the cross-sectional structure;

[0034] Figure 6 For the present invention Figure 5 Enlarged structural diagram at point A in the middle;

[0035] Figure 7 This is a three-dimensional structural diagram of the hot pressing process of the present invention;

[0036] Figure 8 For the present invention Figure 7 A schematic diagram of the cross-sectional structure;

[0037] Figure 9 For the present invention Figure 8 Enlarged structural diagram at point B.

[0038] In the diagram: 1. Top seat; 2. Injection hole; 3. Connecting ear; 4. Piston rod; 5. Buffer cylinder body; 6. Base; 7. Cylindrical seat; 71. Annular limiting protrusion; 72. Heating wire; 73. Annular lifting seat; 74. Flat spring; 75. Annular air bladder; 76. Connecting column; 77. Hollow cavity; 78. Limiting arc groove; 79. Lower platform; 8. Lower mold assembly; 81. Semi-circular lower mold cavity; 82. Inner platform; 83. Outer platform; 84. Channel; 9. Annular upper mold seat; 91. Semi-circular upper mold cavity; 10. Columnar seat; 11. Collection tank; 12. Bend; 13. Exhaust hole; 14. Cylinder piston. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example:

[0041] Please see Figures 1-9 The present invention provides a technical solution:

[0042] A hot pressing mold for rubber gaskets includes a base 6, and a cylindrical seat 7 for placing a lower mold assembly 8 is provided at the middle of the upper end of the base 6.

[0043] The top outer side of the cylindrical seat 7 is provided with an annular limiting protrusion 71;

[0044] The lower mold assembly 8 includes an annular lower mold base and an inner platform 82 and an outer platform 83 integrally formed and connected to the inner and outer sides of the top of the annular lower mold base;

[0045] The inner platform 82 and the outer platform 83 have the same thickness. This arrangement ensures that after the annular upper mold base 9 and the annular lower mold base are closed, the bottom of the annular upper mold base 9 can be tightly attached to the upper surface of the inner platform 82 and the outer platform 83, thereby ensuring that the semi-circular upper mold cavity 91 and the semi-circular lower mold cavity 81 form a sealed molding cavity.

[0046] Furthermore, the outer diameter of the outer platform 83 is consistent with the inner diameter of the annular limiting protrusion 71. This arrangement allows the inner platform 82 to accurately enter the annular limiting protrusion 71 after the lower mold assembly 8 moves down, thereby ensuring that the lower mold assembly 8 will not shift position after it moves down.

[0047] Meanwhile, the outer diameter of the annular upper mold base 9 is the same as the outer diameter of the outer platform 83. This setting allows the annular upper mold base 9 to accurately enter the annular limiting protrusion 71 after it moves down, thus ensuring that the annular upper mold base 9 will not shift position after it moves down.

[0048] This ensures that after the annular upper mold base 9 moves down and closes with the annular lower mold base, the semi-circular upper mold cavity 91 can be aligned with the semi-circular lower mold cavity 81, preventing dimensional deviation of the molding cavity.

[0049] The upper ends of the base 6 are also equipped with buffer cylinder assemblies that are connected to the upper mold assembly on both sides;

[0050] The buffer cylinder assembly includes a buffer cylinder body 5 fixed on both sides of the upper end of the base 6, a cylinder piston 14 disposed inside the buffer cylinder body 5, and a piston rod 4 connected to the middle of the upper end of the cylinder piston 14. The bottom of the buffer cylinder body 5 is connected to the corresponding annular airbag 75 by an air guide pipe.

[0051] The upper mold assembly includes a top seat 1, a columnar seat 10 connected to the lower end of the top seat 1, and an annular upper mold seat 9 fixed to the lower end of the columnar seat 10;

[0052] The top seat 1 is symmetrically provided with connecting ears 3 on its side, and the top of the piston rod 4 extends through the buffer cylinder body 5 and is connected to the bottom of the corresponding connecting ear 3.

[0053] The hydraulic piston rod of the hydraulic cylinder is connected to the upper middle part of the top seat 1 of the upper mold assembly. The extension or retraction of the hydraulic piston rod drives the upper mold assembly to move downward or downward.

[0054] As the upper mold assembly moves downward, the piston rod 4 drives the cylinder piston 14 to move downward along the inside of the buffer cylinder body 5, thereby causing the cylinder piston 14 to compress the air inside the buffer cylinder body 5 into the air guide pipe, and finally force the air into the annular air bag 75, causing the annular air bag 75 to gradually expand as the upper mold assembly moves downward.

[0055] As the cylinder piston 14 moves downward along the inside of the buffer cylinder body 5, it will be subject to the resistance of the air inside the buffer cylinder body 5. This makes the air inside the buffer cylinder body 5 have a certain buffering resistance on the cylinder piston 14, thus playing a buffering role when the upper mold assembly moves downward. This can prevent the annular upper mold seat 9 of the upper mold assembly from hitting the lower mold assembly 8.

[0056] When the upper mold assembly moves upward, the piston rod 4 will drive the cylinder piston 14 to move upward along the inside of the buffer cylinder body 5, thereby creating a negative pressure inside the buffer cylinder body 5, so that the air in the annular airbag 75 enters the buffer cylinder body 5 through the air guide pipe, causing the annular airbag 75 to gradually shrink as the upper mold assembly moves upward.

[0057] The lower platform 79 on the inner top of the cylindrical seat 7 is provided with a limiting arc groove 78 that matches the bottom of the lower mold assembly 8. A heating wire 72 is added inside the limiting arc groove 78.

[0058] The connecting posts 76 on the left and right sides of the lower mold assembly 8 extend into the hollow cavity 77 inside the cylindrical seat 7 and are connected to the annular lifting seat 73. The connecting posts 76 on the left and right sides are symmetrically connected to the lower middle of the outer platform 83, and the connecting posts 76 pass through the openings on the limiting arc groove 78. This arrangement makes the up-and-down movement of the lower mold assembly 8 smoother and more stable, ensuring that the lower mold assembly 8 always moves up and down in a vertical position.

[0059] The bottom of the annular lifting seat 73 is connected to a flat spring 74, and the top of the annular lifting seat 73 is also provided with an annular airbag 75 that is connected to the buffer cylinder assembly.

[0060] When the upper mold assembly descends, the buffer cylinder assembly buffers the upper mold assembly while also injecting air into the annular airbag 75, causing the annular airbag 75 to expand and drive the lower mold assembly 8 to move down until the upper mold assembly is in close contact with the top of the lower mold assembly 8, thus forming a sealed molding cavity between the upper mold assembly and the lower mold assembly 8.

[0061] After the annular airbag 75 inflates, it exerts a downward thrust on the annular lifting seat 73, causing the annular lifting seat 73 to move downward along the hollow cavity 77. This causes the annular lifting seat 73 to drive the lower mold assembly 8 downward through the connecting column 76. At the same time, the annular lifting seat 73 causes the flat spring 74 to gradually compress.

[0062] The lower mold assembly 8 is equipped with an exhaust pipe system. When the rubber gasket molding material is injected into the molding cavity through the injection hole 2 on the upper mold assembly, the air in the molding cavity is discharged through the exhaust pipe system.

[0063] The lower end of the annular upper mold base 9 is provided with a semi-circular upper mold cavity 91, and the upper end of the annular lower mold base is provided with a semi-circular lower mold cavity 81. After the annular upper mold base 9 and the annular lower mold base are closed, the molding cavity is composed of the semi-circular upper mold cavity 91 and the semi-circular lower mold cavity 81.

[0064] The bottom of the injection hole 2 passes through the top seat 1, the columnar seat 10 and the annular upper mold seat 9 in sequence and extends to the top of the semi-circular upper mold cavity 91.

[0065] The exhaust duct system includes several sets of channels 84 arranged at equal intervals inside the inner platform 82, and a collection tank 11 connected by a bend 12 after the inner end of the channel 84 extends to the inner wall of the inner platform 82.

[0066] The top of the collection tank 11 is provided with an exhaust hole 13. When the rubber gasket molding material is injected into the molding cavity through the injection hole 2, the air in the molding cavity is discharged into the collection tank 11 through the exhaust pipe system and communicates with the outside air through the exhaust hole 13.

[0067] The inner end of the bent tube 12 first tilts upward and then downward, forming a bend before extending into the collection tank 11. After the annular upper mold base 9 and the annular lower mold base are closed, the height of the bend of the bent tube 12 is higher than the top of the semi-circular upper mold cavity 91. With this setting, when the heating wire 72 is energized, it generates high temperature and transfers the temperature to the lower mold assembly 8, thereby heating the rubber gasket molding material in the molding cavity. The rubber gasket molding material melts in the molding cavity and fills the molding cavity.

[0068] At this time, the melted rubber gasket molding material also enters the upwardly inclined part of the bend 12 through the channel 84, which is used to discharge the air in the molding cavity through the channel 84 and the bend 12 to the collection tank 11, so that the air in the molding cavity is completely discharged, and the rubber gasket molding material can fill the molding cavity.

[0069] Once the melted rubber gasket molding material continues to increase in the molding cavity, the excess melted rubber gasket molding material can also enter from the inside of the upwardly inclined part of the bend 12 to the inside of the downwardly inclined part of the bend 12, and finally enter the collection tank 11 for temporary storage, for later reuse.

[0070] After the lower mold assembly 8 moves down to the top of the inner side of the cylindrical seat 7, the heating wire 72 is used to heat and keep the rubber gasket molding material in the molding cavity warm.

[0071] After the upper mold assembly moves upward and resets, the upper mold assembly and the lower mold assembly 8 are separated. At the same time, the flat spring 74 is used to move the lower mold assembly 8 upward and reset, thereby pushing out the rubber gasket after hot pressing.

[0072] As the upper mold assembly moves upward, the annular airbag 75 gradually shrinks as the upper mold assembly moves upward. At this time, under the elastic force of the flat spring 74 on the annular lifting seat 73, the annular lifting seat 73 moves upward along the hollow cavity 77, thereby causing the annular lifting seat 73 to drive the lower mold assembly 8 to move upward through the connecting column 76.

[0073] At this time, the air inside the annular airbag 75 enters the buffer cylinder 5 through the air guide pipe, causing the volume of the annular airbag 75 to gradually shrink. The rate at which the volume of the annular airbag 75 gradually shrinks is slow. That is to say, while the flat spring 74 pushes the annular lifting seat 73 upward, the annular airbag 75 also has a certain resistance to the annular lifting seat 73. This makes the upward movement speed of the lower mold assembly 8 less than that of the upper mold assembly. In this way, the upper mold assembly and the lower mold assembly 8 can gradually separate from each other during the upward movement process, until they are separated after the upper mold assembly and the lower mold assembly 8 have moved upward and reset.

[0074] The present invention also provides a molding method for a hot pressing mold for rubber gaskets, specifically including the following steps:

[0075] S1. The upper mold assembly descends, and the buffer cylinder assembly buffers the upper mold assembly. At the same time, the buffer cylinder assembly injects air into the annular airbag 75, causing the annular airbag 75 to expand and drive the lower mold assembly 8 to move down. The upper mold assembly is pressed against the top of the lower mold assembly 8, so that the upper mold assembly and the lower mold assembly 8 move down synchronously until the lower mold assembly 8 sits on the top of the inner side of the cylindrical seat 7, so that a sealed molding cavity is formed between the upper mold assembly and the lower mold assembly 8.

[0076] S2. When the rubber gasket molding material is injected into the molding cavity through the injection hole 2 on the upper mold assembly, the air in the molding cavity is discharged through the exhaust pipe system. At the same time, the heating wire 72 heats and keeps the rubber gasket molding material in the molding cavity warm.

[0077] S3. After the rubber gasket is formed by hot pressing of the rubber gasket molding material in the molding cavity, the upper mold assembly moves upward and resets, and the upper mold assembly and lower mold assembly 8 separate. At the same time, the flat spring 74 pushes the lower mold assembly 8 to move upward and reset, thereby pushing out the rubber gasket.

[0078] Specifically, during use, the hydraulic piston rod of the hydraulic cylinder extends, causing the upper mold assembly to descend. The connecting lug 3 of the upper mold assembly drives the piston rod 4 and the cylinder piston 14 to move downward. The air inside the buffer cylinder body 5 provides a certain buffering resistance to the cylinder piston 14, thereby playing a buffering role when the upper mold assembly moves downward.

[0079] At the same time, the cylinder piston 14 compresses the air inside the buffer cylinder 5 into the air guide pipe, and finally forces the air into the annular air bag 75. The annular air bag 75 gradually expands, and the annular air bag 75 exerts a downward thrust on the annular lifting seat 73, causing the annular lifting seat 73 to move downward along the hollow cavity 77. This causes the annular lifting seat 73 to drive the lower mold assembly 8 to move downward through the connecting column 76. At the same time, the annular lifting seat 73 causes the flat spring 74 to gradually be in a compressed state.

[0080] The upper mold assembly moves downward at a speed greater than that of the lower mold assembly 8. After the upper mold assembly is in close contact with the top of the lower mold assembly 8, the upper mold assembly pushes the lower mold assembly 8 to move downward synchronously until the lower mold assembly 8 sits on the top of the inner side of the cylindrical seat 7, so that a sealed molding cavity is formed between the upper mold assembly and the lower mold assembly 8.

[0081] Rubber gasket molding material is injected into the molding cavity through injection hole 2. After the heating wire 72 is energized, high temperature is generated and the temperature is transferred to the lower mold assembly 8, thereby heating the rubber gasket molding material in the molding cavity. The rubber gasket molding material melts in the molding cavity and fills the molding cavity.

[0082] At this time, the melted rubber gasket molding material also enters the upwardly inclined part of the bend 12 through the channel 84, which is used to discharge the air in the molding cavity through the channel 84 and the bend 12 to the collection tank 11, so that the air in the molding cavity is completely discharged, and the rubber gasket molding material can fill the molding cavity.

[0083] After the rubber gasket is formed by hot pressing the raw material in the molding cavity, the upper mold assembly moves upward and resets, and the upper mold assembly and lower mold assembly 8 separate. At the same time, the flat spring 74 pushes the lower mold assembly 8 upward and resets, thereby ejecting the rubber gasket. Finally, the rubber gasket is removed from the semi-circular lower mold cavity 81, and the part formed inside the channel 84 and the bend 12 is trimmed to obtain the finished rubber gasket.

[0084] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hot-press molding die for rubber gaskets, comprising a base, characterized in that: The upper middle part of the base is provided with a cylindrical seat for placing the lower mold assembly; The upper two sides of the base are also provided with buffer cylinder assemblies that are connected to the upper mold assembly; The lower platform at the top inner side of the cylindrical seat is provided with a limiting arc groove that matches the bottom of the lower mold assembly, and a heating wire is provided inside the limiting arc groove. The connecting columns on the left and right sides of the lower end of the lower mold assembly extend into the hollow cavity inside the cylindrical seat and are connected to an annular lifting seat. A flat spring is connected to the bottom of the annular lifting seat, and an annular airbag connected to the buffer cylinder assembly is also provided at the top of the annular lifting seat. When the upper mold assembly descends, the buffer cylinder assembly not only buffers the upper mold assembly, but also injects air into the annular airbag, causing the annular airbag to expand and drive the lower mold assembly to move down until the upper mold assembly is in close contact with the top of the lower mold assembly, thus forming a sealed molding cavity between the upper mold assembly and the lower mold assembly. The lower mold assembly is equipped with an exhaust pipe system. When the rubber gasket molding material is injected into the molding cavity through the injection hole on the upper mold assembly, the air in the molding cavity is discharged through the exhaust pipe system. After the lower mold assembly moves down to the top of the inner side of the cylindrical seat, the heating wire is used to heat and keep the rubber gasket molding material in the molding cavity warm; After the upper mold assembly moves upward and resets, the upper mold assembly and the lower mold assembly are separated. At the same time, the flat spring is used to move the lower mold assembly upward and reset, thereby pushing out the rubber gasket after hot pressing. The buffer cylinder assembly includes a buffer cylinder body fixed on both sides of the upper end of the base, a cylinder piston disposed inside the buffer cylinder body, and a piston rod connected to the middle of the upper end of the cylinder piston. The bottom of the buffer cylinder body is connected to the corresponding annular airbag via an air guide pipe. The upper mold assembly includes a top seat, a columnar seat connected to the lower end of the top seat, and an annular upper mold seat fixed to the lower end of the columnar seat; The top seat is symmetrically provided with connecting ears on its side, and the top of the piston rod extends through the buffer cylinder body and connects to the bottom of the corresponding connecting ear; The top outer side of the cylindrical seat is provided with an annular limiting protrusion; The lower mold assembly includes an annular lower mold base and an inner platform and an outer platform integrally formed and connected to the inner and outer sides of the top of the annular lower mold base; The inner and outer platforms have the same thickness, and the outer diameter of the outer platform is the same as the inner diameter of the annular limiting protrusion. The connecting columns on the left and right sides are symmetrically connected to the middle of the lower end of the outer platform, and the connecting columns pass through the openings on the limiting arc groove. The annular upper mold base has a semi-circular upper mold cavity at the lower center, and the annular lower mold base has a semi-circular lower mold cavity at the upper center. After the annular upper mold base and the annular lower mold base are closed, the molding cavity is composed of the semi-circular upper mold cavity and the semi-circular lower mold cavity. The bottom of the injection hole passes through the top seat, the columnar seat and the annular upper mold seat in sequence and extends to the top of the semi-circular upper mold cavity; The exhaust duct system includes several sets of channels evenly spaced inside the inner platform and a collection tank connected by a bend after the inner end of the channel extends to the inner wall of the inner platform. The inner end of the bent tube first tilts upward and then downward, forming a bend before extending into the collection tank. After the annular upper mold base and the annular lower mold base are closed, the height of the bend in the bent tube is higher than the top of the semi-circular upper mold cavity. The top of the collection tank is provided with an exhaust hole.

2. A molding method using the hot pressing mold for rubber gaskets as described in claim 1, characterized in that: Specifically, the following steps are included: S1. The upper mold assembly descends, and the buffer cylinder assembly buffers the upper mold assembly. At the same time, the buffer cylinder assembly fills the annular air bladder with air, causing the annular air bladder to expand and drive the lower mold assembly to move down. The upper mold assembly is pressed against the top of the lower mold assembly, so that the upper mold assembly and the lower mold assembly move down synchronously until the lower mold assembly sits on the top of the inner side of the cylindrical seat, so that a sealed molding cavity is formed between the upper mold assembly and the lower mold assembly. S2. When the rubber gasket molding material is injected into the molding cavity through the injection hole on the upper mold assembly, the air in the molding cavity is discharged through the exhaust pipe system. At the same time, the heating wire heats and keeps the rubber gasket molding material in the molding cavity warm. S3. After the rubber gasket is formed by hot pressing of the raw material in the molding cavity, the upper mold assembly moves upward and resets, and the upper mold assembly and the lower mold assembly separate. At the same time, the flat spring pushes the lower mold assembly to move upward and reset, thereby pushing the rubber gasket out.

Images