Hot press molding method and mold for rubber gasket

Abstract

The invention relates to the technical field of hot press molding, and discloses a hot press molding method and mold for a rubber gasket. A cylindrical seat for placing a lower mold assembly is arranged in the middle of the upper end of a base; when rubber gasket forming raw materials are fed into the forming cavity through the injection hole, air in the forming cavity is exhausted through the exhaust pipeline system; after the upper die assembly moves upwards and resets, the upper die assembly is separated from the lower die assembly, meanwhile, the flat spring is used for achieving upward movement and resets of the lower die assembly, and therefore the rubber gasket formed through hot pressing is ejected out. Air in the forming cavity is exhausted through the exhaust pipeline system, so that the forming cavity can be filled with rubber gasket forming raw materials; after the upper mold assembly moves upwards and resets, automatic separation of the upper mold assembly and the lower mold assembly can be achieved, subsequent demolding of the rubber gasket is facilitated, meanwhile, the flat spring is used for achieving upward moving and resetting of the lower mold assembly, and therefore the rubber gasket obtained after hot press forming is ejected out, and the rubber gasket can be taken down conveniently.

Description

Technical Field

[0001] The invention relates to the technical field of hot pressing molding, in particular to a hot pressing molding method and a mold for a rubber gasket. Background Art

[0002] The hot press forming process of rubber gaskets is mainly based on the thermoplasticity of rubber materials and the principle of pressure forming. Under heating conditions, the rubber material becomes soft and has a certain fluidity. At this time, it can be squeezed into the desired shape by applying pressure. After cooling, the rubber material solidifies and maintains the shape and size after forming. Before hot press forming, 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. After hot press forming, the upper and lower molds need to be manually disassembled and separated to remove the rubber gasket. And because the molding cavity is generally inside the upper and lower molds, even after the upper and lower molds are disassembled and separated, it is still inconvenient to take the rubber gasket out of the molding cavity. For this reason, we have introduced a hot press forming method and mold for rubber gaskets. Summary of the invention

[0003] The object of the present invention is to provide a method and a mold for hot pressing a rubber gasket to solve the problems raised in the above background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A hot pressing mold for a rubber gasket, comprising a base, wherein a cylindrical seat for placing a lower mold assembly is provided in the middle of the upper end of the base;

[0006] Buffer cylinder assemblies connected to the upper mold assembly are also provided on both sides of the upper end of the base;

[0007] A limiting arc groove matching the bottom of the lower mold assembly is provided in the middle of the lower platform at the inner top of the cylindrical seat, 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 air bag connected to the buffer cylinder assembly is also provided on 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, so that 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, so that a sealed molding cavity is formed between the upper mold assembly and the lower mold assembly;

[0010] An exhaust pipe system is provided on the inner side of the lower mold assembly. 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;

[0012] After the upper die assembly is moved upward and reset, the upper die assembly and the lower die assembly are separated. At the same time, the flat spring is used to move the lower die assembly upward and reset, thereby ejecting the rubber gasket after hot pressing.

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

[0014] The lower die assembly includes an annular lower die 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 die base;

[0015] The inner platform and the outer platform have the same thickness from top to bottom, and the outer diameter of the outer platform is consistent with the inner diameter of the annular limiting protrusion;

[0016] The connecting columns on the left and right sides are symmetrically connected to the middle part 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 arranged inside the buffer cylinder body, and a piston rod connected to the middle part 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 comprises 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 side of the top seat is symmetrically provided with connecting ears, and the top of the piston rod penetrates through the buffer cylinder body and is connected to the bottom of the corresponding connecting ear.

[0020] Preferably, a semicircular upper mold cavity is provided in the middle of the lower end of the annular upper mold base, and a semicircular lower mold cavity is provided in the middle of the upper end of the annular lower mold base. After the annular upper mold base and the annular lower mold base are molded together, the molding cavity consists of a semicircular upper mold cavity and a semicircular lower mold cavity.

[0021] The bottom of the injection hole sequentially passes through the top seat, the columnar seat and the annular upper mold seat and then extends to the top of the semicircular upper mold cavity.

[0022] Preferably, the exhaust duct system includes a plurality of groups of channels arranged at equal intervals inside the inner platform and a collection tank connected via a bend after the inner ends of the channels extend to the inner wall of the inner platform.

[0023] Preferably, the inner end of the bent pipe is first tilted upward and then downward, forming a bend and then extending into the interior of the collection tank. After the annular upper mold base and the annular lower mold base are molded together, the height of the bent pipe is higher than the top of the semicircular upper mold cavity, and an exhaust hole is provided on the top of the collection tank.

[0024] The present invention also provides a molding method for a rubber gasket hot pressing molding die, which specifically comprises the following steps:

[0025] S1, the upper mold assembly descends, the buffer cylinder assembly buffers the upper mold assembly, and at the same time, the buffer cylinder assembly injects air into the annular airbag, so that the annular airbag expands and drives the lower mold assembly to move downward, and the upper mold assembly is closely attached to the top of the lower mold assembly, so that the upper mold assembly and the lower mold assembly move downward synchronously until the lower mold assembly is seated 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, and 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 molding material in the molding cavity is hot-pressed to form a rubber gasket, the upper mold assembly is moved upward and reset, and the upper mold assembly and the lower mold assembly are separated. At the same time, the flat spring pushes the lower mold assembly upward and reset, thereby ejecting the rubber gasket.

[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 of the present invention plays a buffering role on the upper mold assembly, and at the same time, 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, so that a sealed molding cavity is formed between the upper mold assembly and the lower mold assembly; an exhaust duct system is provided on the inner side of the lower mold assembly, and when the rubber gasket molding material is added into the molding cavity through the injection hole on the upper mold assembly, the air in the molding cavity is discharged through the exhaust duct system, which is conducive to the rubber gasket molding material filling the molding cavity; after the upper mold assembly is moved up and reset, the upper mold assembly and the lower mold assembly can be automatically separated, which is convenient for the subsequent demolding of the rubber gasket. At the same time, the flat spring is used to realize the upward reset of the lower mold assembly, thereby ejecting the rubber gasket after hot pressing molding, which is convenient for removing the rubber gasket. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention in the initial state;

[0030] Figure 2 It 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 3A schematic diagram of the three-dimensional structure of 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 cross-sectional structure diagram of ;

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

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

[0035] Figure 7 It is a schematic diagram of the three-dimensional structure during hot pressing molding of the present invention;

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

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

[0038] In the figure: 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 bag; 76. connecting column; 77. hollow cavity; 78. limiting arc groove; 79. lower platform; 8. lower mold assembly; 81. semicircular lower mold cavity; 82. inner platform; 83. outer platform; 84. channel; 9. annular upper mold seat; 91. semicircular upper mold cavity; 10. columnar seat; 11. collecting tank; 12. elbow; 13. exhaust hole; 14. cylinder piston. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Example:

[0041] See also Figure 1-9 , the present invention provides a technical solution:

[0042] A hot pressing mold for a rubber gasket, comprising a base 6, wherein a cylindrical seat 7 for placing a lower mold assembly 8 is provided in the middle of the upper end of the base 6;

[0043] An annular limiting protrusion 71 is provided on the top of the outer side of the cylindrical seat 7;

[0044] The lower die assembly 8 includes an annular lower die 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 die base;

[0045] The thickness of the inner platform 82 and the outer platform 83 are consistent from top to bottom. After the annular upper mold base 9 and the annular lower mold base are molded together, the bottom of the annular upper mold base 9 can be closely attached to the upper end surface of the inner platform 82 and the outer platform 83, thereby ensuring that the semicircular upper mold cavity 91 and the semicircular lower mold cavity 81 form a sealed molding cavity.

[0046] The outer diameter of the outer platform 83 is consistent with the inner diameter of the annular limiting protrusion 71. Such a setting allows the inner platform 82 to accurately enter the annular limiting protrusion 71 after the lower mold assembly 8 moves downward, thereby ensuring that the lower mold assembly 8 will not be offset after moving downward.

[0047] At the same time, the outer diameter of the annular upper die seat 9 is consistent with the outer diameter of the outer platform 83. Such a setting allows the annular upper die seat 9 to accurately enter the annular limiting protrusion 71 after the annular upper die seat 9 moves downward, thereby ensuring that the annular upper die seat 9 will not be offset after moving downward.

[0048] This ensures that after the annular upper die base 9 moves downward and closes with the annular lower die base, the semicircular upper die cavity 91 can be aligned with the semicircular lower die cavity 81, and does not cause dimensional deviation of the molding cavity.

[0049] Buffer cylinder assemblies connected to the upper mold assembly are also provided on both sides of the upper end of the base 6;

[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 arranged inside the buffer cylinder body 5, and a piston rod 4 connected to the middle part of the upper end of the cylinder piston 14, and the bottom of the buffer cylinder body 5 is connected to the corresponding annular airbag 75 by an air guide pipe.

[0051] The upper die assembly comprises a top seat 1, a columnar seat 10 connected to the lower end of the top seat 1, and an annular upper die 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 penetrates 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 middle of the upper end of the top seat 1 of the upper die assembly, and the upper die assembly is driven to move upward or downward by extending or retracting the hydraulic piston rod;

[0054] When the upper mold assembly moves downward, the piston rod 4 will drive the cylinder piston 14 to move downward along the inside of the buffer cylinder body 5, so that the cylinder piston 14 compresses the air inside the buffer cylinder body 5 into the air duct, and finally presses the air into the annular airbag 75, so that the annular airbag 75 gradually expands as the upper mold assembly moves downward.

[0055] As the cylinder piston 14 moves downward along the buffer cylinder body 5, it will encounter resistance from the air inside the buffer cylinder body 5. As a result, the air inside the buffer cylinder body 5 has a certain buffering resistance to the cylinder piston 14. As a result, when the upper mold assembly moves downward, it plays a buffering role when the upper mold assembly moves downward, thereby preventing the annular upper mold base 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, so that the cylinder piston 14 forms 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 duct, so that the annular airbag 75 gradually shrinks as the upper mold assembly moves upward.

[0057] A limiting arc groove 78 matching the bottom of the lower mold assembly 8 is provided in the middle of the lower platform 79 on the inner top of the cylindrical seat 7, and a heating wire 72 is added inside the limiting arc groove 78;

[0058] The connecting columns 76 on the left and right sides of the lower end 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 columns 76 on the left and right sides are symmetrically connected to the middle of the lower end of the outer platform 83, and the connecting columns 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 is always in a vertical state of up and down movement.

[0059] A flat spring 74 is connected to the bottom of the annular lifting seat 73, and an annular air bag 75 connected to the buffer cylinder assembly is also provided on the top of the annular lifting seat 73;

[0060] 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 75, so that the annular airbag 75 expands and drives the lower mold assembly 8 to move downward until the upper mold assembly is tightly attached to the top of the lower mold assembly 8, so that a sealed molding cavity is formed between the upper mold assembly and the lower mold assembly 8;

[0061] After the annular airbag 75 expands, 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, thereby causing 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.

[0062] An exhaust duct system is provided inside the lower mold assembly 8. 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 duct system.

[0063] A semicircular upper mold cavity 91 is provided in the middle of the lower end of the annular upper mold base 9, and a semicircular lower mold cavity 81 is provided in the middle of the upper end of the annular lower mold base. After the annular upper mold base 9 and the annular lower mold base are molded together, the molding cavity is composed of the semicircular upper mold cavity 91 and the semicircular 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 then extends to the top of the semicircular upper mold cavity 91 .

[0065] The exhaust pipe system includes a plurality of groups of channels 84 arranged at equal intervals inside the inner platform 82 and a collection tank 11 whose inner ends extend to the inner wall of the inner platform 82 and are connected through a bend 12 .

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

[0067] The inner end of the curved tube 12 is tilted upward first and then downward, and then extends into the interior of the collecting tank 11 after being bent. After the annular upper die seat 9 and the annular lower die seat are molded together, the height of the bent part of the curved tube 12 is higher than the top of the semicircular upper die cavity 91. With this arrangement, when the heating wire 72 is energized, high temperature is generated, and the temperature is transferred to the lower die assembly 8, thereby heating the rubber gasket molding material in the molding cavity, and 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 elbow 12 through the channel 84, and is used to discharge the air in the molding cavity through the channel 84 and the elbow 12 into the collection tank 11, so that the air in the molding cavity is completely discharged, so that 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 the downwardly inclined part of the elbow 12 from the upwardly inclined part of the elbow 12, and finally enter the collection tank 11 for temporary storage for subsequent 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;

[0071] After the upper mold assembly is moved upward and reset, 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 ejecting the rubber gasket after hot pressing.

[0072] When 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, so that the annular lifting seat 73 drives 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 body 5 through the air guide duct, so that the volume of the annular airbag 75 gradually decreases. The speed at which the volume of the annular airbag 75 gradually decreases 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 effect on the annular lifting seat 73, so that the upward movement speed of the lower mold assembly 8 is lower than the upward movement speed 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 the upper mold assembly and the lower mold assembly 8 are moved up and reset, and then the separation is achieved.

[0074] The present invention also provides a molding method for a rubber gasket hot pressing molding die, which specifically comprises the following steps:

[0075] S1, the upper mold assembly descends, the buffer cylinder assembly buffers the upper mold assembly, and at the same time, the buffer cylinder assembly injects air into the annular airbag 75, so that the annular airbag 75 expands and drives the lower mold assembly 8 to move downward, and the upper mold assembly is tightly attached to the top of the lower mold assembly 8, so that the upper mold assembly and the lower mold assembly 8 move downward synchronously until the lower mold assembly 8 is seated 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 added 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 duct system, and 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 molding material in the molding cavity is hot-pressed to form a rubber gasket, the upper mold assembly is moved upward and reset, and the upper mold assembly and the lower mold assembly 8 are separated. At the same time, the flat spring 74 pushes the lower mold assembly 8 to move upward and reset, thereby ejecting the rubber gasket.

[0078] Specifically, when in use, the hydraulic piston rod of the hydraulic cylinder extends, causing the upper mold assembly to descend, and the connecting ear 3 of the upper mold assembly drives the piston rod 4 and the cylinder piston 14 to move downward, and the air inside the buffer cylinder body 5 has 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 body 5 into the air guide pipe, and finally presses the air into the annular airbag 75. The annular airbag 75 gradually expands, and the annular airbag 75 has a downward thrust on the annular lifting seat 73, so that the annular lifting seat 73 moves downward along the hollow cavity 77, so that the annular lifting seat 73 drives the lower mold assembly 8 to move downward through the connecting column 76. At the same time, the annular lifting seat 73 makes the flat spring 74 gradually in a compressed state;

[0080] The speed at which the upper mold assembly moves downward is greater than the speed at which the lower mold assembly 8 moves downward. 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 is seated 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] The rubber gasket molding material is injected into the molding cavity through the injection hole 2. After the heating wire 72 is energized, high temperature is generated and the temperature is transmitted 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 elbow 12 through the channel 84, and is used to discharge the air in the molding cavity through the channel 84 and the elbow 12 into the collection tank 11, so that the air in the molding cavity is completely discharged, so that the rubber gasket molding material can fill the molding cavity;

[0083] After the rubber gasket molding material in the molding cavity is hot-pressed to form a rubber gasket, the upper mold assembly is moved upward and reset, and the upper mold assembly and the lower mold assembly 8 are separated. At the same time, the flat spring 74 pushes the lower mold assembly 8 to move upward and reset, thereby ejecting the rubber gasket. Finally, the rubber gasket is removed from the semicircular lower mold cavity 81, and the parts formed in the channel 84 and the inner part of the curved pipe 12 are trimmed to obtain the finished rubber gasket.

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

Claims

1. A hot pressing mold for a rubber gasket, comprising a base, characterized in that: A cylindrical seat for placing the lower mold assembly is provided in the middle of the upper end of the base; Buffer cylinder assemblies connected to the upper mold assembly are also provided on both sides of the upper end of the base; A limiting arc groove matching the bottom of the lower mold assembly is provided in the middle of the lower platform at the inner top of the cylindrical seat, and a heating wire is added 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 air bag connected to the buffer cylinder assembly is also provided on 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, so that 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, so that a sealed molding cavity is formed between the upper mold assembly and the lower mold assembly; An exhaust pipe system is provided on the inner side of the lower mold assembly. 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; After the upper die assembly is moved upward and reset, the upper die assembly and the lower die assembly are separated. At the same time, the flat spring is used to move the lower die assembly upward and reset, thereby ejecting the rubber gasket after hot pressing.

2. The hot pressing mold for rubber gasket according to claim 1, characterized in that: The outer top of the cylindrical seat is provided with an annular limiting protrusion; The lower die assembly includes an annular lower die 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 die base; The inner platform and the outer platform have the same thickness from top to bottom, and the outer diameter of the outer platform is consistent with the inner diameter of the annular limiting protrusion; The connecting columns on the left and right sides are symmetrically connected to the middle part of the lower end of the outer platform, and the connecting columns pass through the openings on the limiting arc groove.

3. The hot pressing mold for rubber gasket according to claim 2, characterized in that: The buffer cylinder assembly includes a buffer cylinder body fixed on both sides of the upper end of the base, a cylinder piston arranged inside the buffer cylinder body, and a piston rod connected to the middle part of the upper end of the cylinder piston, and the bottom of the buffer cylinder body is connected to the corresponding annular airbag through an air guide pipe.

4. The hot pressing mold for rubber gasket according to claim 3, characterized in that: The upper die assembly comprises a top seat, a columnar seat connected to the lower end of the top seat, and an annular upper die seat fixed to the lower end of the columnar seat; The side of the top seat is symmetrically provided with connecting ears, and the top of the piston rod penetrates through the buffer cylinder body and is connected to the bottom of the corresponding connecting ear.

5. The hot pressing mold for rubber gasket according to claim 4, characterized in that: A semicircular upper mold cavity is provided in the middle of the lower end of the annular upper mold base, and a semicircular lower mold cavity is provided in the middle of the upper end of the annular lower mold base. After the annular upper mold base and the annular lower mold base are molded together, the molding cavity is composed of a semicircular upper mold cavity and a semicircular lower mold cavity. The bottom of the injection hole sequentially passes through the top seat, the columnar seat and the annular upper mold seat and then extends to the top of the semicircular upper mold cavity.

6. The hot pressing mold for rubber gasket according to claim 5, characterized in that: The exhaust pipe system includes a plurality of groups of channels arranged at equal intervals inside the inner platform and a collection tank connected via a bend pipe after the inner ends of the channels extend to the inner wall of the inner platform.

7. The hot pressing mold for rubber gasket according to claim 7, characterized in that: The inner end of the bent pipe first tilts upward and then downward, forming a bend and then extending into the collection tank. After the annular upper mold base and the annular lower mold base are molded together, the height of the bent pipe is higher than the top of the semicircular upper mold cavity, and an exhaust hole is provided on the top of the collection tank.

8. A molding method for a rubber gasket hot pressing mold according to any one of claims 1 to 7, characterized in that: The specific steps include: S1, the upper mold assembly descends, the buffer cylinder assembly buffers the upper mold assembly, and at the same time, the buffer cylinder assembly injects air into the annular airbag, so that the annular airbag expands and drives the lower mold assembly to move downward, and the upper mold assembly is closely attached to the top of the lower mold assembly, so that the upper mold assembly and the lower mold assembly move downward synchronously until the lower mold assembly is seated 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, and 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 molding material in the molding cavity is hot-pressed to form a rubber gasket, the upper mold assembly is moved upward and reset, and the upper mold assembly and the lower mold assembly are separated. At the same time, the flat spring pushes the lower mold assembly upward and reset, thereby ejecting the rubber gasket.

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