An integrated sealing device for a piston and a sealing method thereof

Abstract

The present invention discloses an integrated sealing device for a piston, comprising a piston, a cylinder body and a sealing device, wherein the piston is arranged in the inner cavity of the cylinder body, the sealing device comprises a metal ring and a copper powder filled polytetrafluoroethylene ring arranged in sequence from the inside to the outside, a clamping nut is arranged below the sealing device, the clamping nut is threadedly connected to the bottom of the piston, the metal ring is arranged on the outer side of the lower part of the piston, the copper powder filled polytetrafluoroethylene ring is thermally mounted on the outer side of the metal ring, the interference between the copper powder filled polytetrafluoroethylene ring and the metal ring is 10 mm, and the outer wall of the copper powder filled polytetrafluoroethylene ring is in contact with the inner cavity side wall of the cylinder body. The present invention also discloses a sealing method. The present invention effectively improves the wear resistance, self-lubrication and deformation resistance of the sealing device, and increases the service life of the sealing device.

Description

Technical Field

[0001] The invention relates to an integrated sealing device for a piston and a sealing method thereof, belonging to the field of industrial sealing. Background Art

[0002] In the field of metallurgy, hydraulic cylinders are the main actuators, and their performance directly affects the final quality of rolled products. The selection of sealing elements is particularly important for the performance and service life of hydraulic cylinders. Usually, the sealed part is between two mechanical coupling surfaces that need to be sealed. At the same time, according to whether the coupling surfaces have relative movement during mechanical operation, the seal is divided into two categories: dynamic seal and static seal. The one-piece seal ring for pistons involved in the present invention is mainly used in dynamic sealing occasions. The traditional dynamic seal is composed of a sealing ring made of polytetrafluoroethylene material and a traditional rubber square ring. Through radial interference fit, the rubber square ring is compressed to play a sealing role. The working medium in the hydraulic cylinder is mostly No. 46 anti-wear hydraulic oil. If the rubber square ring is used in this environment for a long time, the aging speed of the square ring will be accelerated, affecting the service life of the seal. The installation process of the traditional dynamic seal is complicated. It is necessary to first install the rubber square ring into the sealing groove, and then heat the polytetrafluoroethylene sealing ring and install it into the groove. If the temperature and assembly force are not well controlled in the assembly process, the size of the polytetrafluoroethylene sealing ring will become larger and cannot be restored, and eventually it will be unusable. Summary of the invention

[0003] The purpose of the present invention is to provide an integrated sealing device for a piston, and also to provide a sealing method for the integrated sealing device for a piston, which is composed of a copper powder-filled polytetrafluoroethylene ring and a metal ring, effectively improving the wear resistance, self-lubrication and deformation resistance of the sealing device, and increasing the service life of the sealing device.

[0004] To solve the above technical problems, the present invention adopts the following technical solutions: an integrated sealing device for a piston, comprising a piston, a cylinder body and a sealing device, wherein the piston is arranged in the inner cavity of the cylinder body, the sealing device comprises a metal ring and a copper powder-filled polytetrafluoroethylene ring arranged in sequence from the inside to the outside, a clamping nut is arranged below the sealing device, the clamping nut is threadedly connected to the bottom of the piston, the metal ring is arranged on the outer side of the lower part of the piston, the copper powder-filled polytetrafluoroethylene ring is heat-fitted on the outer side of the metal ring, the interference between the copper powder-filled polytetrafluoroethylene ring and the metal ring is 10 mm, and the outer wall of the copper powder-filled polytetrafluoroethylene ring is in contact with the inner cavity side wall of the cylinder body; the copper powder-filled polytetrafluoroethylene ring effectively improves the wear resistance and self-lubrication of the seal, the use of the metal ring improves the deformation resistance of the integrated sealing device, and increases the service life of the sealing device, the clamping nut is threadedly connected to the bottom of the piston, the sealing device is compressed, and the overall sealing performance of the sealing device is increased.

[0005] The aforementioned integrated sealing device for a piston has a first groove between the piston and the metal ring, and an O-ring is provided on the inner surface of the first groove; the O-ring performs static sealing, thereby improving the overall performance of the sealing device.

[0006] The aforementioned integrated sealing device for a piston has a rod chamber between the side wall of the piston and the inner chamber of the cylinder body, and a rodless chamber between the bottom of the piston and the inner chamber of the cylinder body; the rod chamber and the rodless chamber store pressurized oil, and when the piston moves, the pressure difference in the cylinder body is changed under the action of the oil pressure.

[0007] The aforementioned integrated sealing device for a piston, the outer surface of the metal ring is provided with a plurality of second grooves, the second grooves are equidistantly distributed on the outer surface of the metal ring, the distance between the plurality of second grooves is 10 mm, the roughness of the outer surface of the metal ring is 12.5 um, and the roughness of the inner surface of the metal ring is 0.8 um; during the hot-loading process, the air in the second groove will be discharged due to the increase in heat, and a negative pressure area will be formed in the second groove after the hot-loading, so that the copper powder-filled polytetrafluoroethylene ring is tightly attached to the metal ring, the roughness of the outer surface of the metal ring is 12.5 um, and the roughness of the inner surface of the metal ring is 0.8 um, thereby improving the overall performance of the sealing device.

[0008] The aforementioned integrated sealing device for a piston, wherein the outer surface of the copper powder filled polytetrafluoroethylene ring is provided with a plurality of annular oil grooves, the annular oil grooves are equidistantly distributed on the outer surface of the copper powder filled polytetrafluoroethylene ring, and the distance between the plurality of annular oil grooves is 20 mm; when the pressure oil in the cylinder body flows into the annular oil grooves, the outer surface of the copper powder filled polytetrafluoroethylene ring will be closely attached to the inner wall of the cylinder body under the action of the oil pressure.

[0009] The aforementioned one-piece sealing device for a piston, the inner surface of the copper powder filled polytetrafluoroethylene ring is provided with a heat-shrink fitting surface, the roughness of the heat-shrink fitting surface is 6.3um, the outer surface of the copper powder filled polytetrafluoroethylene ring is provided with a dynamic sealing fitting surface, the dynamic sealing fitting surface includes an upper dynamic sealing fitting surface, a lower dynamic sealing fitting surface and a middle guide surface, the diameter of the upper dynamic sealing fitting surface is larger than the inner diameter of the cylinder body and the difference is 0.5-0.55mm, the inner diameter of the lower dynamic sealing fitting surface is The diameter of the middle guide surface is smaller than the inner diameter of the cylinder body and the difference is 0.5-0.55mm; the diameter of the middle guide surface is smaller than the inner diameter of the cylinder body and the difference is 0.05-0.1mm; the roughness of the heat-fitting fitting surface is 6.3um, so that the copper powder filled polytetrafluoroethylene ring is tightly attached to the metal ring; when the pressure oil in the cylinder body flows into the dynamic seal fitting surface, due to the difference in diameter between the dynamic seal fitting surface and the cylinder body, the dynamic seal fitting surface will be tightly attached to the inner wall of the cylinder body under the action of oil pressure, thereby improving the overall performance of the sealing device.

[0010] The aforementioned integrated sealing device for a piston, wherein the upper dynamic seal fitting surface is provided with a first inclined surface on a side away from the inner cavity side wall of the cylinder body, and the lower dynamic seal fitting surface is provided with a second inclined surface on a side away from the inner cavity side wall of the cylinder body, an angle a is provided between the first inclined surface and the piston, and an angle b is provided between the second inclined surface and the clamping nut, and both a and b are 0.5°; when the piston moves, when the pressure oil flows into the angle a and the angle b, the upper dynamic seal fitting surface and the lower dynamic seal fitting surface will be tightly attached to the inner wall of the cylinder body under the action of the oil pressure.

[0011] The aforementioned integrated sealing device for a piston has an upper inner cavity provided between the first inclined surface and the piston, and a lower inner cavity provided between the second inclined surface and the clamping nut; the upper inner cavity is the angle area between the first inclined surface and the piston, and the lower inner cavity is the angle area between the second inclined surface and the clamping nut. When the pressure oil flows into the upper inner cavity and the lower inner cavity, the upper dynamic seal fitting surface and the lower dynamic seal fitting surface will be tightly attached to the inner wall of the cylinder body under the action of the oil pressure.

[0012] In the aforementioned one-piece sealing device for a piston, the material of the metal ring 4 is 42 chrome-molybdenum steel; 42 chrome-molybdenum steel has high strength and toughness, good low-temperature impact toughness, and deformation resistance, which increases the service life of the sealing device 3.

[0013] A sealing method for an integrated sealing device for a piston, comprising the following steps:

[0014] S1, insert the O-ring into the first groove;

[0015] S2, a metal ring is sleeved on the outer side of the lower part of the piston on which the O-ring is installed;

[0016] S3, first heat the copper powder filled polytetrafluoroethylene ring; then put the heated copper powder filled polytetrafluoroethylene ring on the outside of the metal ring; in the process of hot-fitting the copper powder filled polytetrafluoroethylene ring on the outside of the metal ring, make the hot-fitting bonding surface of the copper powder filled polytetrafluoroethylene ring close to the metal ring, the heating temperature is 165℃-175℃, and the heating time is 45-55 minutes.

[0017] Compared with the prior art, the present invention includes a piston, a cylinder body and a sealing device, wherein the piston is arranged in the inner cavity of the cylinder body, and the sealing device includes a metal ring and a copper powder-filled polytetrafluoroethylene ring arranged in sequence from the inside to the outside, and the outer wall of the copper powder-filled polytetrafluoroethylene ring is in contact with the inner cavity side wall of the cylinder body. At the same time, a sealing method for an integrated sealing device for a piston is provided. The present invention effectively improves the wear resistance, self-lubrication and deformation resistance of the sealing device, and increases the service life of the sealing device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention;

[0019] Figure 2 It is a schematic structural diagram of the sealing device of the present invention;

[0020] Figure 3 The present invention Figure 1 A magnified view of middle;

[0021] Figure 4 The present invention Figure 1 Enlarged view of middle B;

[0022] Figure 5 The present invention Figure 1 Enlarged view of middle C;

[0023] Figure 6 It is an isometric view of the sealing device of the present invention.

[0024] Figure markings: 1-piston, 2-cylinder body, 3-sealing device, 4-metal ring, 5-copper powder filled polytetrafluoroethylene ring, 6-pressure nut, 7-first groove, 8-O-ring, 9-rod chamber, 10-rodless chamber, 11-second groove, 12-annular oil groove, 13-scaling fitting surface, 14-dynamic sealing fitting surface, 15-upper dynamic sealing fitting surface, 16-lower dynamic sealing fitting surface, 17-middle guide surface, 18-first inclined surface, 19-second inclined surface, 20-upper inner cavity, 21-lower inner cavity.

[0025] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. DETAILED DESCRIPTION

[0026] Embodiment 1 of the present invention: An integrated sealing device for a piston comprises a piston 1, a cylinder body 2 and a sealing device 3, wherein the piston 1 is arranged in the inner cavity of the cylinder body 2, the sealing device 3 comprises a metal ring 4 and a copper powder filled polytetrafluoroethylene ring 5 which are arranged in sequence from the inside to the outside, a clamping nut 6 is arranged below the sealing device 3, the clamping nut 6 is threadedly connected to the bottom of the piston 1, the metal ring 4 is arranged on the outer side of the lower part of the piston 1, the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4, the interference between the copper powder filled polytetrafluoroethylene ring 5 and the metal ring 4 is 10 mm, and the outer wall of the copper powder filled polytetrafluoroethylene ring 5 is in contact with the inner cavity side wall of the cylinder body 2; the copper powder filled polytetrafluoroethylene ring 5 effectively improves the wear resistance and self-lubrication of the seal, the use of the metal ring 4 improves the deformation resistance of the integrated sealing device 3, and increases the service life of the sealing device 3, the clamping nut 6 is threadedly connected to the bottom of the piston 1, the sealing device 3 is compressed, and the overall sealing performance of the sealing device 3 is increased.

[0027] Embodiment 2 of the present invention: An integrated sealing device for a piston, comprising a piston 1, a cylinder body 2 and a sealing device 3, wherein the piston 1 is arranged in the inner cavity of the cylinder body 2, the sealing device 3 comprises a metal ring 4 and a copper powder filled polytetrafluoroethylene ring 5 arranged in sequence from the inside to the outside, a clamping nut 6 is arranged below the sealing device 3, the clamping nut 6 is threadedly connected to the bottom of the piston 1, the metal ring 4 is arranged on the outer side of the lower part of the piston 1, the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4, and the copper powder filled polytetrafluoroethylene ring 5 is connected to the bottom of the piston 1. The interference fit between the metal rings 4 is 10 mm, and the outer wall of the copper powder filled polytetrafluoroethylene ring 5 is in contact with the inner cavity side wall of the cylinder body 2; the copper powder filled polytetrafluoroethylene ring 5 effectively improves the wear resistance and self-lubricating property of the seal, and the use of the metal ring 4 improves the deformation resistance of the integrated sealing device 3, and increases the service life of the sealing device 3; the clamping nut 6 is threadedly connected to the bottom of the piston 1 to compress the sealing device 3, thereby increasing the overall sealing performance of the sealing device 3; a first groove 7 is provided between the piston 1 and the metal ring 4, and an O-ring 8 is provided on the inner surface of the first groove 7; the O-ring 8 performs static sealing, thereby improving the overall performance of the sealing device 3.

[0028] Embodiment 3 of the present invention: An integrated sealing device for a piston, comprising a piston 1, a cylinder body 2 and a sealing device 3, wherein the piston 1 is arranged in the inner cavity of the cylinder body 2, the sealing device 3 comprises a metal ring 4 and a copper powder filled polytetrafluoroethylene ring 5 arranged in sequence from the inside to the outside, a clamping nut 6 is arranged below the sealing device 3, the clamping nut 6 is threadedly connected to the bottom of the piston 1, the metal ring 4 is arranged on the outer side of the lower part of the piston 1, the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4, and the copper powder filled polytetrafluoroethylene ring 5 is connected to the bottom of the piston 1. The interference between the metal rings 4 is 10 mm, and the outer wall of the copper powder filled polytetrafluoroethylene ring 5 is in contact with the inner cavity side wall of the cylinder body 2; the copper powder filled polytetrafluoroethylene ring 5 effectively improves the wear resistance and self-lubricating property of the seal, and the use of the metal ring 4 improves the anti-deformation ability of the integrated sealing device 3 and increases the service life of the sealing device 3. The clamping nut 6 is threadedly connected to the bottom of the piston 1 to compress the sealing device 3, thereby increasing the overall sealing performance of the sealing device 3; a first groove 7 is provided between the piston 1 and the metal ring 4, and an O-ring 8 is provided on the inner surface of the first groove 7; the O-ring 8 performs static sealing, thereby improving the overall performance of the sealing device 3; a rod cavity 9 is provided between the side wall of the piston 1 and the inner cavity of the cylinder body 2, and a rodless cavity 10 is provided between the bottom of the piston 1 and the inner cavity of the cylinder body 2; the rod cavity 9 and the rodless cavity 10 store pressure oil, and when the piston 1 moves, the pressure difference in the cylinder body 2 is changed under the action of the oil pressure.

[0029] Embodiment 4 of the present invention: An integrated sealing device for a piston, comprising a piston 1, a cylinder body 2 and a sealing device 3, wherein the piston 1 is arranged in the inner cavity of the cylinder body 2, the sealing device 3 comprises a metal ring 4 and a copper powder filled polytetrafluoroethylene ring 5 arranged in sequence from the inside to the outside, a clamping nut 6 is arranged below the sealing device 3, the clamping nut 6 is threadedly connected to the bottom of the piston 1, the metal ring 4 is arranged on the outer side of the lower part of the piston 1, the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4, and the copper powder filled polytetrafluoroethylene ring 5 is connected to the bottom of the piston 1. The interference between the metal rings 4 is 10 mm, and the outer wall of the copper powder filled polytetrafluoroethylene ring 5 is in contact with the inner cavity side wall of the cylinder body 2; the copper powder filled polytetrafluoroethylene ring 5 effectively improves the wear resistance and self-lubrication of the seal, and the use of the metal ring 4 improves the deformation resistance of the integrated sealing device 3 and increases the service life of the sealing device 3. The clamping nut 6 is threadedly connected to the bottom of the piston 1 to tighten the sealing device 3, thereby increasing the overall sealing performance of the sealing device 3; a first groove 7 is provided between the piston 1 and the metal ring 4, and the first groove 7 The inner surface of the metal ring 4 is provided with an O-ring 8; the O-ring 8 performs static sealing, thereby improving the overall performance of the sealing device 3; a rod cavity 9 is provided between the side wall of the piston 1 and the inner cavity of the cylinder body 2, and a rodless cavity 10 is provided between the bottom of the piston 1 and the inner cavity of the cylinder body 2; the rod cavity 9 and the rodless cavity 10 store pressure oil, and when the piston 1 moves, the pressure difference in the cylinder body 2 is changed under the action of the oil pressure; the outer surface of the metal ring 4 is provided with a plurality of second grooves 11, and the second grooves 11 are equidistantly distributed on the outer surface of the metal ring 4 The distance between the multiple second grooves 11 is 10 mm, the roughness of the outer surface of the metal ring 4 is 12.5 um, and the roughness of the inner surface of the metal ring 4 is 0.8 um; during the hot-loading process, the air in the second groove 11 will be discharged due to the increase in heat, and a negative pressure area will be formed in the second groove 11 after the hot-loading, so that the copper powder-filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4, the roughness of the outer surface of the metal ring 4 is 12.5 um, and the roughness of the inner surface of the metal ring 4 is 0.8 um, thereby improving the overall performance of the sealing device 3.

[0030] Embodiment 5 of the present invention: An integrated sealing device for a piston, comprising a piston 1, a cylinder body 2 and a sealing device 3, wherein the piston 1 is arranged in the inner cavity of the cylinder body 2, the sealing device 3 comprises a metal ring 4 and a copper powder filled polytetrafluoroethylene ring 5 arranged in sequence from the inside to the outside, a clamping nut 6 is arranged below the sealing device 3, the clamping nut 6 is threadedly connected to the bottom of the piston 1, the metal ring 4 is arranged on the outer side of the lower part of the piston 1, the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4, and the copper powder filled polytetrafluoroethylene ring 5 is connected to the bottom of the piston 1. The interference between the metal rings 4 is 10 mm, and the outer wall of the copper powder filled polytetrafluoroethylene ring 5 is in contact with the inner cavity side wall of the cylinder body 2; the copper powder filled polytetrafluoroethylene ring 5 effectively improves the wear resistance and self-lubrication of the seal, and the use of the metal ring 4 improves the deformation resistance of the integrated sealing device 3 and increases the service life of the sealing device 3. The clamping nut 6 is threadedly connected to the bottom of the piston 1 to tighten the sealing device 3, thereby increasing the overall sealing performance of the sealing device 3; a first groove 7 is provided between the piston 1 and the metal ring 4, and the first groove 7 The inner surface of the piston 1 is provided with an O-ring 8; the O-ring 8 performs static sealing, thereby improving the overall performance of the sealing device 3; a rod cavity 9 is provided between the side wall of the piston 1 and the inner cavity of the cylinder body 2, and a rodless cavity 10 is provided between the bottom of the piston 1 and the inner cavity of the cylinder body 2; the rod cavity 9 and the rodless cavity 10 store pressure oil, and when the piston 1 moves, the pressure difference in the cylinder body 2 is changed under the action of the oil pressure; the outer surface of the metal ring 4 is provided with a plurality of second grooves 11, and the second grooves 11 are equidistantly distributed on the outer surface of the metal ring 4, and the distance between the plurality of second grooves 11 is 10mm, the roughness of the outer surface of the metal ring 4 is 12.5um, and the roughness of the inner surface of the metal ring 4 is 0.8um; during the hot-loading process, the second grooves 11 are arranged on the outer surface of the metal ring 4, and the second grooves 11 are arranged on the outer surface of the metal ring 4, and the distance between the plurality of second grooves 11 is 10mm, and the roughness of the outer surface of the metal ring 4 is 12.5um, and the roughness of the inner surface of the metal ring 4 is 0.8um; during the hot-loading process, the second grooves 11 are arranged on the outer surface of the metal ring 4, and ... The air in the second groove 11 will be discharged due to the increase in heat, and a negative pressure area will be formed in the second groove 11 after hot installation, so that the copper powder filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4, the roughness of the outer surface of the metal ring 4 is 12.5um, and the roughness of the inner surface of the metal ring 4 is 0.8um, thereby improving the overall performance of the sealing device 3; the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a plurality of annular oil grooves 12, and the annular oil grooves 12 are equidistantly distributed on the outer surface of the copper powder filled polytetrafluoroethylene ring 5, and the distance between the plurality of annular oil grooves 12 is 20mm; when the pressure oil in the cylinder body 2 flows into the annular oil groove 12, the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is tightly attached to the inner wall of the cylinder body 2 under the action of the oil pressure.

[0031] Embodiment 6 of the present invention: An integrated sealing device for a piston, comprising a piston 1, a cylinder body 2 and a sealing device 3, wherein the piston 1 is arranged in the inner cavity of the cylinder body 2, the sealing device 3 comprises a metal ring 4 and a copper powder filled polytetrafluoroethylene ring 5 arranged in sequence from the inside to the outside, a clamping nut 6 is arranged below the sealing device 3, the clamping nut 6 is threadedly connected to the bottom of the piston 1, the metal ring 4 is arranged on the outer side of the lower part of the piston 1, the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4, and the copper powder filled polytetrafluoroethylene ring 5 is connected to the bottom of the piston 1. The interference between the metal rings 4 is 10 mm, and the outer wall of the copper powder filled polytetrafluoroethylene ring 5 is in contact with the inner cavity side wall of the cylinder body 2; the copper powder filled polytetrafluoroethylene ring 5 effectively improves the wear resistance and self-lubrication of the seal, and the use of the metal ring 4 improves the deformation resistance of the integrated sealing device 3 and increases the service life of the sealing device 3. The clamping nut 6 is threadedly connected to the bottom of the piston 1 to tighten the sealing device 3, thereby increasing the overall sealing performance of the sealing device 3; a first groove 7 is provided between the piston 1 and the metal ring 4, and the first groove 7 The inner surface is provided with an O-ring 8; the O-ring 8 performs static sealing, thereby improving the overall performance of the sealing device 3; a rod cavity 9 is provided between the side wall of the piston 1 and the inner cavity of the cylinder body 2, and a rodless cavity 10 is provided between the bottom of the piston 1 and the inner cavity of the cylinder body 2; the rod cavity 9 and the rodless cavity 10 store pressure oil, and when the piston 1 moves, the pressure difference in the cylinder body 2 is changed under the action of the oil pressure; the outer surface of the metal ring 4 is provided with a plurality of second grooves 11, and the second grooves 11 are equidistantly distributed on the outer surface of the metal ring 4, and the distance between the plurality of second grooves 11 is 10mm, the roughness of the outer surface of the metal ring 4 is 12.5um, and the roughness of the inner surface of the metal ring 4 is 0.8um; during the hot-loading process, the air in the second groove 11 will be discharged due to the increase of heat, and a negative pressure area will be formed in the second groove 11 after hot-loading, so that the copper powder-filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4, and the roughness of the outer surface of the metal ring 4 is 1 The outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a plurality of annular oil grooves 12, and the annular oil grooves 12 are evenly distributed on the outer surface of the copper powder filled polytetrafluoroethylene ring 5, and the distance between the plurality of annular oil grooves 12 is 20mm; when the pressure oil in the cylinder body 2 flows into the annular oil grooves 12, the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is made of the oil pressure. The surface is close to the inner wall of the cylinder body 2; the inner surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a heat-shrink fitting surface 13, the roughness of the heat-shrink fitting surface 13 is 6.3um, and the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a dynamic sealing fitting surface 14, the dynamic sealing fitting surface 14 includes an upper dynamic sealing fitting surface 15, a lower dynamic sealing fitting surface 16 and a middle guide surface 17, the diameter of the upper dynamic sealing fitting surface 15 is larger than the inner diameter of the cylinder body 2 and the difference is 0.5-0.55mm, the inner diameter of the lower dynamic seal fitting surface 16 is larger than the diameter of the cylinder body 2 and the difference is 0.5-0.55mm, the diameter of the middle guide surface 17 is smaller than the inner diameter of the cylinder body 2 and the difference is 0.05-0.1mm; the roughness of the heat-fitting fitting surface 13 is 6.3um, so that the copper powder filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4; when the pressure oil in the cylinder body 2 flows into the dynamic seal fitting surface 14, because there is a difference between the diameter of the dynamic seal fitting surface 14 and the cylinder body 2, the dynamic seal fitting surface 14 will be tightly attached to the inner wall of the cylinder body 2 under the action of oil pressure, thereby improving the overall performance of the sealing device 3. .

[0032] Embodiment 7 of the present invention: An integrated sealing device for a piston, comprising a piston 1, a cylinder body 2 and a sealing device 3, wherein the piston 1 is arranged in the inner cavity of the cylinder body 2, the sealing device 3 comprises a metal ring 4 and a copper powder filled polytetrafluoroethylene ring 5 arranged in sequence from the inside to the outside, a clamping nut 6 is arranged below the sealing device 3, the clamping nut 6 is threadedly connected to the bottom of the piston 1, the metal ring 4 is arranged on the outer side of the lower part of the piston 1, the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4, and the copper powder filled polytetrafluoroethylene ring 5 is connected to the bottom of the piston 1. The interference between the metal rings 4 is 10 mm, and the outer wall of the copper powder filled polytetrafluoroethylene ring 5 is in contact with the inner cavity side wall of the cylinder body 2; the copper powder filled polytetrafluoroethylene ring 5 effectively improves the wear resistance and self-lubrication of the seal, and the use of the metal ring 4 improves the deformation resistance of the integrated sealing device 3 and increases the service life of the sealing device 3. The clamping nut 6 is threadedly connected to the bottom of the piston 1 to tighten the sealing device 3, thereby increasing the overall sealing performance of the sealing device 3; a first groove 7 is provided between the piston 1 and the metal ring 4, and the first groove 7 The inner surface is provided with an O-ring 8; the O-ring 8 performs static sealing, thereby improving the overall performance of the sealing device 3; a rod cavity 9 is provided between the side wall of the piston 1 and the inner cavity of the cylinder body 2, and a rodless cavity 10 is provided between the bottom of the piston 1 and the inner cavity of the cylinder body 2; the rod cavity 9 and the rodless cavity 10 store pressure oil, and when the piston 1 moves, the pressure difference in the cylinder body 2 is changed under the action of the oil pressure; the outer surface of the metal ring 4 is provided with a plurality of second grooves 11, and the second grooves 11 are equidistantly distributed on the outer surface of the metal ring 4, and the distance between the plurality of second grooves 11 is 10mm, the roughness of the outer surface of the metal ring 4 is 12.5um, and the roughness of the inner surface of the metal ring 4 is 0.8um; during the hot-loading process, the air in the second groove 11 will be discharged due to the increase of heat, and a negative pressure area will be formed in the second groove 11 after hot-loading, so that the copper powder-filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4, and the roughness of the outer surface of the metal ring 4 is 1 The outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a plurality of annular oil grooves 12, and the annular oil grooves 12 are evenly distributed on the outer surface of the copper powder filled polytetrafluoroethylene ring 5, and the distance between the plurality of annular oil grooves 12 is 20mm; when the pressure oil in the cylinder body 2 flows into the annular oil grooves 12, the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is made of the oil pressure. The surface is close to the inner wall of the cylinder body 2; the inner surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a heat-shrink fitting surface 13, the roughness of the heat-shrink fitting surface 13 is 6.3um, and the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a dynamic sealing fitting surface 14, the dynamic sealing fitting surface 14 includes an upper dynamic sealing fitting surface 15, a lower dynamic sealing fitting surface 16 and a middle guide surface 17, the diameter of the upper dynamic sealing fitting surface 15 is larger than the inner diameter of the cylinder body 2 and the difference is 0.5-0.55mm, the inner diameter of the lower dynamic seal fitting surface 16 is larger than the diameter of the cylinder body 2 and the difference is 0.5-0.55mm, the diameter of the middle guide surface 17 is smaller than the inner diameter of the cylinder body 2 and the difference is 0.05-0.1mm; the roughness of the hot-fitting fitting surface 13 is 6.3um, so that the copper powder filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4; when the pressure oil in the cylinder body 2 flows into the dynamic seal fitting surface 14, due to the diameter of the dynamic seal fitting surface 14 and the cylinder body 2 The difference is that the dynamic seal fitting surface 14 is tightly attached to the inner wall of the cylinder body 2 under the action of oil pressure, thereby improving the overall performance of the sealing device 3; the upper dynamic seal fitting surface 15 is provided with a first inclined surface 18 on the side away from the inner cavity side wall of the cylinder body 2, and the lower dynamic seal fitting surface 16 is provided with a second inclined surface 19 on the side away from the inner cavity side wall of the cylinder body 2, and an angle a is set between the first inclined surface 18 and the piston 1, and an angle b is set between the second inclined surface 19 and the clamping nut 6, and both a and b are 0.5°; when the piston 1 moves, when the pressure oil flows into the angle a and the angle b, the upper dynamic seal fitting surface 15 and the lower dynamic seal fitting surface 16 are tightly attached to the inner wall of the cylinder body 2 under the action of oil pressure. .

[0033] Embodiment 8 of the present invention: An integrated sealing device for a piston, comprising a piston 1, a cylinder body 2 and a sealing device 3, wherein the piston 1 is arranged in the inner cavity of the cylinder body 2, the sealing device 3 comprises a metal ring 4 and a copper powder filled polytetrafluoroethylene ring 5 arranged in sequence from the inside to the outside, a clamping nut 6 is arranged below the sealing device 3, the clamping nut 6 is threadedly connected to the bottom of the piston 1, the metal ring 4 is arranged on the outer side of the lower part of the piston 1, the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4, and the copper powder filled polytetrafluoroethylene ring 5 is connected to the bottom of the piston 1. The interference between the metal rings 4 is 10 mm, and the outer wall of the copper powder filled polytetrafluoroethylene ring 5 is in contact with the inner cavity side wall of the cylinder body 2; the copper powder filled polytetrafluoroethylene ring 5 effectively improves the wear resistance and self-lubrication of the seal, and the use of the metal ring 4 improves the deformation resistance of the integrated sealing device 3 and increases the service life of the sealing device 3. The clamping nut 6 is threadedly connected to the bottom of the piston 1 to tighten the sealing device 3, thereby increasing the overall sealing performance of the sealing device 3; a first groove 7 is provided between the piston 1 and the metal ring 4, and the first groove 7 The inner surface is provided with an O-ring 8; the O-ring 8 performs static sealing, thereby improving the overall performance of the sealing device 3; a rod cavity 9 is provided between the side wall of the piston 1 and the inner cavity of the cylinder body 2, and a rodless cavity 10 is provided between the bottom of the piston 1 and the inner cavity of the cylinder body 2; the rod cavity 9 and the rodless cavity 10 store pressure oil, and when the piston 1 moves, the pressure difference in the cylinder body 2 is changed under the action of the oil pressure; the outer surface of the metal ring 4 is provided with a plurality of second grooves 11, and the second grooves 11 are equidistantly distributed on the outer surface of the metal ring 4, and the distance between the plurality of second grooves 11 is 10mm, the roughness of the outer surface of the metal ring 4 is 12.5um, and the roughness of the inner surface of the metal ring 4 is 0.8um; during the hot-loading process, the air in the second groove 11 will be discharged due to the increase of heat, and a negative pressure area will be formed in the second groove 11 after hot-loading, so that the copper powder-filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4, and the roughness of the outer surface of the metal ring 4 is 1 The outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a plurality of annular oil grooves 12, and the annular oil grooves 12 are evenly distributed on the outer surface of the copper powder filled polytetrafluoroethylene ring 5, and the distance between the plurality of annular oil grooves 12 is 20mm; when the pressure oil in the cylinder body 2 flows into the annular oil grooves 12, the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is made of the oil pressure. The surface is close to the inner wall of the cylinder body 2; the inner surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a heat-shrink fitting surface 13, the roughness of the heat-shrink fitting surface 13 is 6.3um, and the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a dynamic sealing fitting surface 14, the dynamic sealing fitting surface 14 includes an upper dynamic sealing fitting surface 15, a lower dynamic sealing fitting surface 16 and a middle guide surface 17, the diameter of the upper dynamic sealing fitting surface 15 is larger than the inner diameter of the cylinder body 2 and the difference is 0.5-0.55mm, the inner diameter of the lower dynamic seal fitting surface 16 is larger than the diameter of the cylinder body 2 and the difference is 0.5-0.55mm, the diameter of the middle guide surface 17 is smaller than the inner diameter of the cylinder body 2 and the difference is 0.05-0.1mm; the roughness of the hot-fitting fitting surface 13 is 6.3um, so that the copper powder filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4; when the pressure oil in the cylinder body 2 flows into the dynamic seal fitting surface 14, due to the diameter of the dynamic seal fitting surface 14 and the cylinder body 2 The difference is that the dynamic seal fitting surface 14 will be in close contact with the inner wall of the cylinder body 2 under the action of oil pressure, thereby improving the overall performance of the sealing device 3; the upper dynamic seal fitting surface 15 is provided with a first inclined surface 18 on the side away from the inner cavity side wall of the cylinder body 2, and the lower dynamic seal fitting surface 16 is provided with a second inclined surface 19 on the side away from the inner cavity side wall of the cylinder body 2, an angle a is set between the first inclined surface 18 and the piston 1, and an angle b is set between the second inclined surface 19 and the compression nut 6, and the angle a is and b are both 0.5°; when the piston 1 moves, when the pressure oil flows into the angle a and the angle b, the upper dynamic seal fitting surface 15 and the lower dynamic seal fitting surface 16 will be in close contact with the inner wall of the cylinder body 2 under the action of the oil pressure; an upper inner cavity 20 is provided between the first inclined surface 18 and the piston 1, and a lower inner cavity 21 is provided between the second inclined surface 19 and the clamping nut 6; the upper inner cavity 20 is the angle area between the first inclined surface 18 and the piston 1, and the lower inner cavity 21 is the angle area between the second inclined surface 19 and the clamping nut 6. When the pressure oil flows into the upper inner cavity 20 and the lower inner cavity 21, the upper dynamic seal fitting surface 15 and the lower dynamic seal fitting surface 16 will be in close contact with the inner wall of the cylinder body 2 under the action of the oil pressure. .

[0034] Embodiment 9 of the present invention: An integrated sealing device for a piston, comprising a piston 1, a cylinder body 2 and a sealing device 3, wherein the piston 1 is arranged in the inner cavity of the cylinder body 2, the sealing device 3 comprises a metal ring 4 and a copper powder filled polytetrafluoroethylene ring 5 arranged in sequence from the inside to the outside, a clamping nut 6 is arranged below the sealing device 3, the clamping nut 6 is threadedly connected to the bottom of the piston 1, the metal ring 4 is arranged on the outer side of the lower part of the piston 1, the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4, and the copper powder filled polytetrafluoroethylene ring 5 is connected to the bottom of the piston 1. The interference between the metal rings 4 is 10 mm, and the outer wall of the copper powder filled polytetrafluoroethylene ring 5 is in contact with the inner cavity side wall of the cylinder body 2; the copper powder filled polytetrafluoroethylene ring 5 effectively improves the wear resistance and self-lubrication of the seal, and the use of the metal ring 4 improves the deformation resistance of the integrated sealing device 3 and increases the service life of the sealing device 3. The clamping nut 6 is threadedly connected to the bottom of the piston 1 to tighten the sealing device 3, thereby increasing the overall sealing performance of the sealing device 3; a first groove 7 is provided between the piston 1 and the metal ring 4, and the first groove 7 The inner surface is provided with an O-ring 8; the O-ring 8 performs static sealing, thereby improving the overall performance of the sealing device 3; a rod cavity 9 is provided between the side wall of the piston 1 and the inner cavity of the cylinder body 2, and a rodless cavity 10 is provided between the bottom of the piston 1 and the inner cavity of the cylinder body 2; the rod cavity 9 and the rodless cavity 10 store pressure oil, and when the piston 1 moves, the pressure difference in the cylinder body 2 is changed under the action of the oil pressure; the outer surface of the metal ring 4 is provided with a plurality of second grooves 11, and the second grooves 11 are equidistantly distributed on the outer surface of the metal ring 4, and the distance between the plurality of second grooves 11 is 10mm, the roughness of the outer surface of the metal ring 4 is 12.5um, and the roughness of the inner surface of the metal ring 4 is 0.8um; during the hot-loading process, the air in the second groove 11 will be discharged due to the increase of heat, and a negative pressure area will be formed in the second groove 11 after hot-loading, so that the copper powder-filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4, and the roughness of the outer surface of the metal ring 4 is 1 The outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a plurality of annular oil grooves 12, and the annular oil grooves 12 are evenly distributed on the outer surface of the copper powder filled polytetrafluoroethylene ring 5, and the distance between the plurality of annular oil grooves 12 is 20mm; when the pressure oil in the cylinder body 2 flows into the annular oil grooves 12, the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is made of the oil pressure. The surface is close to the inner wall of the cylinder body 2; the inner surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a heat-shrink fitting surface 13, the roughness of the heat-shrink fitting surface 13 is 6.3um, and the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a dynamic sealing fitting surface 14, the dynamic sealing fitting surface 14 includes an upper dynamic sealing fitting surface 15, a lower dynamic sealing fitting surface 16 and a middle guide surface 17, the diameter of the upper dynamic sealing fitting surface 15 is larger than the inner diameter of the cylinder body 2 and the difference is 0.5-0.55mm, the inner diameter of the lower dynamic seal fitting surface 16 is larger than the diameter of the cylinder body 2 and the difference is 0.5-0.55mm, the diameter of the middle guide surface 17 is smaller than the inner diameter of the cylinder body 2 and the difference is 0.05-0.1mm; the roughness of the hot-fitting fitting surface 13 is 6.3um, so that the copper powder filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4; when the pressure oil in the cylinder body 2 flows into the dynamic seal fitting surface 14, due to the diameter of the dynamic seal fitting surface 14 and the cylinder body 2 The difference is that the dynamic seal fitting surface 14 will be in close contact with the inner wall of the cylinder body 2 under the action of oil pressure, thereby improving the overall performance of the sealing device 3; the upper dynamic seal fitting surface 15 is provided with a first inclined surface 18 on the side away from the inner cavity side wall of the cylinder body 2, and the lower dynamic seal fitting surface 16 is provided with a second inclined surface 19 on the side away from the inner cavity side wall of the cylinder body 2, an angle a is set between the first inclined surface 18 and the piston 1, and an angle b is set between the second inclined surface 19 and the compression nut 6, and the angle a is and b are both 0.5°; when the piston 1 moves, when the pressure oil flows into the angle a and the angle b, the upper dynamic seal fitting surface 15 and the lower dynamic seal fitting surface 16 will be in close contact with the inner wall of the cylinder body 2 under the action of the oil pressure; an upper inner cavity 20 is provided between the first inclined surface 18 and the piston 1, and a lower inner cavity 21 is provided between the second inclined surface 19 and the clamping nut 6; the upper inner cavity 20 is the angle area between the first inclined surface 18 and the piston 1, and the lower inner cavity 21 is the angle area between the second inclined surface 19 and the clamping nut 6. When the pressure oil flows into the upper inner cavity 20 and the lower inner cavity 21, the upper dynamic seal fitting surface 15 and the lower dynamic seal fitting surface 16 will be in close contact with the inner wall of the cylinder body 2 under the action of the oil pressure; the material of the metal ring 4 is 42 chrome-molybdenum steel; 42 chrome-molybdenum steel has high strength and toughness, good low-temperature impact toughness, and anti-deformation ability, which increases the service life of the sealing device 3. .

[0035] A sealing method for an integrated sealing device for a piston, comprising the following steps:

[0036] S1, insert the O-ring 8 into the first groove 7;

[0037] S2, the metal ring 4 is sleeved on the outer side of the lower part of the piston 1 on which the O-ring 8 is installed;

[0038] S3, first heat the copper powder filled polytetrafluoroethylene ring 5; then put the heated copper powder filled polytetrafluoroethylene ring 5 on the outside of the metal ring 4; in the process of hot-fitting the copper powder filled polytetrafluoroethylene ring 5 on the outside of the metal ring 4, the hot-fitting bonding surface 13 of the copper powder filled polytetrafluoroethylene ring 5 is closely attached to the metal ring 4, the heating temperature is 165℃-175℃, and the heating time is 45-55 minutes.

[0039] Embodiment 10 of the present invention: An integrated sealing device for a piston, comprising a piston 1, a cylinder body 2 and a sealing device 3, wherein the piston 1 is arranged in the inner cavity of the cylinder body 2, the sealing device 3 comprises a metal ring 4 and a copper powder filled polytetrafluoroethylene ring 5 arranged in sequence from the inside to the outside, a clamping nut 6 is arranged below the sealing device 3, the clamping nut 6 is threadedly connected to the bottom of the piston 1, the metal ring 4 is arranged on the outer side of the lower part of the piston 1, the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4, and the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4. The interference with the metal ring 4 is 10mm, and the outer wall of the copper powder filled polytetrafluoroethylene ring 5 is in contact with the inner cavity side wall of the cylinder body 2; the copper powder filled polytetrafluoroethylene ring 5 effectively improves the wear resistance and self-lubrication of the seal, and the use of the metal ring 4 improves the deformation resistance of the integrated sealing device 3 and increases the service life of the sealing device 3. The clamping nut 6 is threadedly connected to the bottom of the piston 1 to tighten the sealing device 3, thereby increasing the overall sealing performance of the sealing device 3; a first groove 7 is provided between the piston 1 and the metal ring 4, and the first groove 7 The inner surface is provided with an O-ring 8; the O-ring 8 performs static sealing, thereby improving the overall performance of the sealing device 3; a rod cavity 9 is provided between the side wall of the piston 1 and the inner cavity of the cylinder body 2, and a rodless cavity 10 is provided between the bottom of the piston 1 and the inner cavity of the cylinder body 2; the rod cavity 9 and the rodless cavity 10 store pressure oil, and when the piston 1 moves, the pressure difference in the cylinder body 2 is changed under the action of the oil pressure; a plurality of second grooves 11 are provided on the outer surface of the metal ring 4, and the second grooves 11 are equidistantly distributed on the outer surface of the metal ring 4, and the distance between the plurality of second grooves 11 is 10mm, the roughness of the outer surface of the metal ring 4 is 12.5um, and the roughness of the inner surface of the metal ring 4 is 0.8um; during the hot-loading process, the air in the second groove 11 will be discharged due to the increase in heat, and a negative pressure area will be formed in the second groove 11 after hot-loading, so that the copper powder-filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4, and the roughness of the outer surface of the metal ring 4 The roughness of the inner surface of the metal ring 4 is 12.5um, and the roughness of the inner surface of the metal ring 4 is 0.8um, which improves the overall performance of the sealing device 3; the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a plurality of annular oil grooves 12, and the annular oil grooves 12 are evenly distributed on the outer surface of the copper powder filled polytetrafluoroethylene ring 5, and the distance between the plurality of annular oil grooves 12 is 20mm; when the pressure oil in the cylinder body 2 flows into the annular oil groove 12, the copper powder filled polytetrafluoroethylene ring 5 is caused to be filled with oil under the action of the oil pressure. The outer surface of the copper powder filled polytetrafluoroethylene ring 5 is in close contact with the inner wall of the cylinder 2; the inner surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a heat-shrink fitting surface 13, the roughness of the heat-shrink fitting surface 13 is 6.3um, and the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a dynamic sealing fitting surface 14, the dynamic sealing fitting surface 14 includes an upper dynamic sealing fitting surface 15, a lower dynamic sealing fitting surface 16 and a middle guide surface 17, the diameter of the upper dynamic sealing fitting surface 15 is greater than the inner diameter of the cylinder 2 and the difference is 0.5, the inner diameter of the lower dynamic seal fitting surface 16 is larger than the diameter of the cylinder body 2 and the difference is 0.5, the diameter of the middle guide surface 17 is smaller than the inner diameter of the cylinder body 2 and the difference is 0.05; the roughness of the shrink-fit fitting surface 13 is 6.3um, so that the copper powder filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4; when the pressure oil in the cylinder body 2 flows into the dynamic seal fitting surface 14, due to the difference in diameter between the dynamic seal fitting surface 14 and the cylinder body 2, the oil pressure will cause The dynamic seal fitting surface 14 is in close contact with the inner wall of the cylinder body 2, which improves the overall performance of the sealing device 3; the upper dynamic seal fitting surface 15 is provided with a first inclined surface 18 on the side away from the inner cavity side wall of the cylinder body 2, and the lower dynamic seal fitting surface 16 is provided with a second inclined surface 19 on the side away from the inner cavity side wall of the cylinder body 2, and an angle a is set between the first inclined surface 18 and the piston 1, and an angle b is set between the second inclined surface 19 and the compression nut 6, and both a and b are 0.5°; the piston 1 During movement, when the pressure oil flows into the angle a and the angle b, the upper dynamic seal fitting surface 15 and the lower dynamic seal fitting surface 16 will be in close contact with the inner wall of the cylinder body 2 under the action of the oil pressure; an upper inner cavity 20 is provided between the first inclined surface 18 and the piston 1, and a lower inner cavity 21 is provided between the second inclined surface 19 and the clamping nut 6; the upper inner cavity 20 is the angle area between the first inclined surface 18 and the piston 1, and the lower inner cavity 21 is the angle area between the second inclined surface 19 and the clamping nut 6. When the pressure oil flows into the upper inner cavity 20 and the lower inner cavity 21, the upper dynamic seal fitting surface 15 and the lower dynamic seal fitting surface 16 will be in close contact with the inner wall of the cylinder body 2 under the action of the oil pressure; the material of the metal ring 4 is 42 chrome-molybdenum steel; 42 chrome-molybdenum steel has high strength and toughness, good low-temperature impact toughness, and anti-deformation ability, which increases the service life of the sealing device 3. .

[0040] A sealing method for an integrated sealing device for a piston, comprising the following steps:

[0041] S1, insert the O-ring 8 into the first groove 7;

[0042] S2, the metal ring 4 is sleeved on the outer side of the lower part of the piston 1 on which the O-ring 8 is installed;

[0043] S3, first heat the copper powder filled polytetrafluoroethylene ring 5; then put the heated copper powder filled polytetrafluoroethylene ring 5 on the outside of the metal ring 4; in the process of hot-fitting the copper powder filled polytetrafluoroethylene ring 5 on the outside of the metal ring 4, the hot-fitting bonding surface 13 of the copper powder filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4, the heating temperature is 165°C, and the heating time is 55 minutes.

[0044] Embodiment 11 of the present invention: An integrated sealing device for a piston, comprising a piston 1, a cylinder body 2 and a sealing device 3, wherein the piston 1 is arranged in the inner cavity of the cylinder body 2, the sealing device 3 comprises a metal ring 4 and a copper powder filled polytetrafluoroethylene ring 5 arranged in sequence from the inside to the outside, a clamping nut 6 is arranged below the sealing device 3, the clamping nut 6 is threadedly connected to the bottom of the piston 1, the metal ring 4 is arranged on the outer side of the lower part of the piston 1, the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4, and the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4. The interference with the metal ring 4 is 10mm, and the outer wall of the copper powder filled polytetrafluoroethylene ring 5 is in contact with the inner cavity side wall of the cylinder body 2; the copper powder filled polytetrafluoroethylene ring 5 effectively improves the wear resistance and self-lubrication of the seal, and the use of the metal ring 4 improves the deformation resistance of the integrated sealing device 3 and increases the service life of the sealing device 3. The clamping nut 6 is threadedly connected to the bottom of the piston 1 to tighten the sealing device 3, thereby increasing the overall sealing performance of the sealing device 3; a first groove 7 is provided between the piston 1 and the metal ring 4, and the first groove 7 The inner surface is provided with an O-ring 8; the O-ring 8 performs static sealing, thereby improving the overall performance of the sealing device 3; a rod cavity 9 is provided between the side wall of the piston 1 and the inner cavity of the cylinder body 2, and a rodless cavity 10 is provided between the bottom of the piston 1 and the inner cavity of the cylinder body 2; the rod cavity 9 and the rodless cavity 10 store pressure oil, and when the piston 1 moves, the pressure difference in the cylinder body 2 is changed under the action of the oil pressure; a plurality of second grooves 11 are provided on the outer surface of the metal ring 4, and the second grooves 11 are equidistantly distributed on the outer surface of the metal ring 4, and the distance between the plurality of second grooves 11 is 10mm, the roughness of the outer surface of the metal ring 4 is 12.5um, and the roughness of the inner surface of the metal ring 4 is 0.8um; during the hot-loading process, the air in the second groove 11 will be discharged due to the increase in heat, and a negative pressure area will be formed in the second groove 11 after hot-loading, so that the copper powder-filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4, and the roughness of the outer surface of the metal ring 4 The roughness of the inner surface of the metal ring 4 is 12.5um, and the roughness of the inner surface of the metal ring 4 is 0.8um, which improves the overall performance of the sealing device 3; the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a plurality of annular oil grooves 12, and the annular oil grooves 12 are evenly distributed on the outer surface of the copper powder filled polytetrafluoroethylene ring 5, and the distance between the plurality of annular oil grooves 12 is 20mm; when the pressure oil in the cylinder body 2 flows into the annular oil groove 12, the copper powder filled polytetrafluoroethylene ring 5 is caused to be filled with oil under the action of the oil pressure. The outer surface of the copper powder filled polytetrafluoroethylene ring 5 is in close contact with the inner wall of the cylinder 2; the inner surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a heat-shrink fitting surface 13, the roughness of the heat-shrink fitting surface 13 is 6.3um, and the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a dynamic sealing fitting surface 14, the dynamic sealing fitting surface 14 includes an upper dynamic sealing fitting surface 15, a lower dynamic sealing fitting surface 16 and a middle guide surface 17, the diameter of the upper dynamic sealing fitting surface 15 is greater than the inner diameter of the cylinder 2 and the difference is 0.55mm, the inner diameter of the lower dynamic seal fitting surface 16 is larger than the diameter of the cylinder body 2 and the difference is 0.55mm, the diameter of the middle guide surface 17 is smaller than the inner diameter of the cylinder body 2 and the difference is 0.1mm; the roughness of the heat-fitting fitting surface 13 is 6.3um, so that the copper powder-filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4; when the pressure oil in the cylinder body 2 flows into the dynamic seal fitting surface 14, due to the difference between the diameter of the dynamic seal fitting surface 14 and the cylinder body 2, the dynamic seal fitting surface 14 will be tightly attached to the inner wall of the cylinder body 2 under the action of oil pressure, thereby improving the overall performance of the sealing device 3; the upper dynamic seal fitting surface 15 is provided with a first inclined surface 18 on the side away from the inner cavity side wall of the cylinder body 2, and the lower dynamic seal fitting surface 16 is provided with a second inclined surface 19 on the side away from the inner cavity side wall of the cylinder body 2, and an angle a is set between the first inclined surface 18 and the piston 1, and the second inclined surface 19 is pressed against the screw An angle b is set between the nut 6, and both a and b are 0.5°; when the piston 1 moves, when the pressure oil flows into the angle a and the angle b, the upper dynamic seal fitting surface 15 and the lower dynamic seal fitting surface 16 will be tightly attached to the inner wall of the cylinder body 2 under the action of oil pressure; an upper inner cavity 20 is set between the first inclined surface 18 and the piston 1, and a lower inner cavity 21 is set between the second inclined surface 19 and the clamping nut 6; the upper inner cavity 20 is the angle area between the first inclined surface 18 and the piston 1, and the lower inner cavity 21 is the angle area between the second inclined surface 19 and the clamping nut 6. When the pressure oil flows into the upper inner cavity 20 and the lower inner cavity 21, the upper dynamic seal fitting surface 15 and the lower dynamic seal fitting surface 16 will be tightly attached to the inner wall of the cylinder body 2 under the action of oil pressure; the material of the metal ring 4 is 42 chrome-molybdenum steel; 42 chrome-molybdenum steel has high strength and toughness, good low-temperature impact toughness, and anti-deformation ability, which increases the service life of the sealing device 3. .

[0045] A sealing method for an integrated sealing device for a piston, comprising the following steps:

[0046] S1, insert the O-ring 8 into the first groove 7;

[0047] S2, the metal ring 4 is sleeved on the outer side of the lower part of the piston 1 on which the O-ring 8 is installed;

[0048] S3, first heat the copper powder filled polytetrafluoroethylene ring 5; then put the heated copper powder filled polytetrafluoroethylene ring 5 on the outside of the metal ring 4; in the process of hot-fitting the copper powder filled polytetrafluoroethylene ring 5 on the outside of the metal ring 4, the hot-fitting bonding surface 13 of the copper powder filled polytetrafluoroethylene ring 5 is closely attached to the metal ring 4, the heating temperature is 170°C, and the heating time is 50 minutes.

[0049] Embodiment 12 of the present invention: An integrated sealing device for a piston, comprising a piston 1, a cylinder body 2 and a sealing device 3, wherein the piston 1 is arranged in the inner cavity of the cylinder body 2, the sealing device 3 comprises a metal ring 4 and a copper powder filled polytetrafluoroethylene ring 5 arranged in sequence from the inside to the outside, a clamping nut 6 is arranged below the sealing device 3, the clamping nut 6 is threadedly connected to the bottom of the piston 1, the metal ring 4 is arranged on the outer side of the lower part of the piston 1, the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4, and the copper powder filled polytetrafluoroethylene ring 5 is heat-fitted on the outer side of the metal ring 4. The interference with the metal ring 4 is 10mm, and the outer wall of the copper powder filled polytetrafluoroethylene ring 5 is in contact with the inner cavity side wall of the cylinder body 2; the copper powder filled polytetrafluoroethylene ring 5 effectively improves the wear resistance and self-lubrication of the seal, and the use of the metal ring 4 improves the deformation resistance of the integrated sealing device 3 and increases the service life of the sealing device 3. The clamping nut 6 is threadedly connected to the bottom of the piston 1 to tighten the sealing device 3, thereby increasing the overall sealing performance of the sealing device 3; a first groove 7 is provided between the piston 1 and the metal ring 4, and the first groove 7 The inner surface is provided with an O-ring 8; the O-ring 8 performs static sealing, thereby improving the overall performance of the sealing device 3; a rod cavity 9 is provided between the side wall of the piston 1 and the inner cavity of the cylinder body 2, and a rodless cavity 10 is provided between the bottom of the piston 1 and the inner cavity of the cylinder body 2; the rod cavity 9 and the rodless cavity 10 store pressure oil, and when the piston 1 moves, the pressure difference in the cylinder body 2 is changed under the action of the oil pressure; the outer surface of the metal ring 4 is provided with a plurality of second grooves 11, and the second grooves 11 are equidistantly distributed on the outer surface of the metal ring 4, and the distance between the plurality of second grooves 11 is 10mm, the roughness of the outer surface of the metal ring 4 is 12.5um, and the roughness of the inner surface of the metal ring 4 is 0.8um; during the hot-loading process, the air in the second groove 11 will be discharged due to the increase of heat, and a negative pressure area will be formed in the second groove 11 after hot-loading, so that the copper powder-filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4, and the roughness of the outer surface of the metal ring 4 is 1 The outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a plurality of annular oil grooves 12, and the annular oil grooves 12 are evenly distributed on the outer surface of the copper powder filled polytetrafluoroethylene ring 5, and the distance between the plurality of annular oil grooves 12 is 20mm; when the pressure oil in the cylinder body 2 flows into the annular oil grooves 12, the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is made of the oil pressure. The surface is close to the inner wall of the cylinder body 2; the inner surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a heat-shrink fitting surface 13, the roughness of the heat-shrink fitting surface 13 is 6.3um, and the outer surface of the copper powder filled polytetrafluoroethylene ring 5 is provided with a dynamic sealing fitting surface 14, the dynamic sealing fitting surface 14 includes an upper dynamic sealing fitting surface 15, a lower dynamic sealing fitting surface 16 and a middle guide surface 17, the diameter of the upper dynamic sealing fitting surface 15 is larger than the inner diameter of the cylinder body 2 and the difference is 0.5-0.55mm, the inner diameter of the lower dynamic seal fitting surface 16 is larger than the diameter of the cylinder body 2 and the difference is 0.5-0.55mm, the diameter of the middle guide surface 17 is smaller than the inner diameter of the cylinder body 2 and the difference is 0.05-0.1mm; the roughness of the hot-fitting fitting surface 13 is 6.3um, so that the copper powder filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4; when the pressure oil in the cylinder body 2 flows into the dynamic seal fitting surface 14, due to the diameter of the dynamic seal fitting surface 14 and the cylinder body 2 The difference is that the dynamic seal fitting surface 14 will be in close contact with the inner wall of the cylinder body 2 under the action of oil pressure, thereby improving the overall performance of the sealing device 3; the upper dynamic seal fitting surface 15 is provided with a first inclined surface 18 on the side away from the inner cavity side wall of the cylinder body 2, and the lower dynamic seal fitting surface 16 is provided with a second inclined surface 19 on the side away from the inner cavity side wall of the cylinder body 2, an angle a is set between the first inclined surface 18 and the piston 1, and an angle b is set between the second inclined surface 19 and the compression nut 6, and the angle a is and b are both 0.5°; when the piston 1 moves, when the pressure oil flows into the angle a and the angle b, the upper dynamic seal fitting surface 15 and the lower dynamic seal fitting surface 16 will be in close contact with the inner wall of the cylinder body 2 under the action of the oil pressure; an upper inner cavity 20 is provided between the first inclined surface 18 and the piston 1, and a lower inner cavity 21 is provided between the second inclined surface 19 and the clamping nut 6; the upper inner cavity 20 is the angle area between the first inclined surface 18 and the piston 1, and the lower inner cavity 21 is the angle area between the second inclined surface 19 and the clamping nut 6. When the pressure oil flows into the upper inner cavity 20 and the lower inner cavity 21, the upper dynamic seal fitting surface 15 and the lower dynamic seal fitting surface 16 will be in close contact with the inner wall of the cylinder body 2 under the action of the oil pressure; the material of the metal ring 4 is 42 chrome-molybdenum steel; 42 chrome-molybdenum steel has high strength and toughness, good low-temperature impact toughness, and anti-deformation ability, which increases the service life of the sealing device 3. .

[0050] A sealing method for an integrated sealing device for a piston, comprising the following steps:

[0051] S1, insert the O-ring 8 into the first groove 7;

[0052] S2, the metal ring 4 is sleeved on the outer side of the lower part of the piston 1 on which the O-ring 8 is installed;

[0053] S3, first heat the copper powder filled polytetrafluoroethylene ring 5; then put the heated copper powder filled polytetrafluoroethylene ring 5 on the outside of the metal ring 4; in the process of hot-fitting the copper powder filled polytetrafluoroethylene ring 5 on the outside of the metal ring 4, the hot-fitting bonding surface 13 of the copper powder filled polytetrafluoroethylene ring 5 is tightly attached to the metal ring 4, the heating temperature is 175°C, and the heating time is 45 minutes.

[0054] The working principle of an embodiment of the present invention: the present invention includes a piston 1, a cylinder body 2 and a sealing device 3, wherein the piston 1 is arranged in the inner cavity of the cylinder body 2, and the sealing device 3 includes a metal ring 4 and a copper powder-filled polytetrafluoroethylene ring 5 which are arranged in sequence from the inside to the outside, and the outer wall of the copper powder-filled polytetrafluoroethylene ring 5 is in contact with the inner cavity side wall of the cylinder body 2; when the piston 1 is working, there is pressurized oil in the rod cavity 9, and the pressurized oil will flow into the upper inner cavity 20, and under the action of the oil pressure, the upper dynamic sealing contact surface 15 will be in close contact with the inner wall of the cylinder body 2; there is pressurized oil in the rodless cavity 10 of the hydraulic cylinder, and the pressurized oil will flow into the lower inner cavity 21, and under the action of the oil pressure, the lower dynamic sealing contact surface 16 will be in close contact with the inner wall of the cylinder body 2, thereby improving the overall performance of the sealing device.

Claims

1. An integrated sealing device for a piston, characterized in that: The invention comprises a piston (1), a cylinder (2) and a sealing device (3), wherein the piston (1) is arranged in the inner cavity of the cylinder (2), the sealing device (3) comprises a metal ring (4) and a copper powder filled polytetrafluoroethylene ring (5) arranged in sequence from the inside to the outside, a clamping nut (6) is arranged below the sealing device (3), the clamping nut (6) is connected to the bottom of the piston (1) by a thread, the metal ring (4) is arranged on the outer side of the lower part of the piston (1), the copper powder filled polytetrafluoroethylene ring (5) is arranged on the outer side of the lower part of the piston (1), and the copper powder filled polytetrafluoroethylene ring (6) is arranged on the outer side of the lower part of the piston (1). The polytetrafluoroethylene ring (5) is heat-fitted on the outside of the metal ring (4); the interference between the copper powder-filled polytetrafluoroethylene ring (5) and the metal ring (4) is 10 mm; the outer wall of the copper powder-filled polytetrafluoroethylene ring (5) is in contact with the inner cavity side wall of the cylinder body (2); the inner surface of the copper powder-filled polytetrafluoroethylene ring (5) is provided with a heat-fitting bonding surface (13); the roughness of the heat-fitting bonding surface (13) is 6.3 μm; the outer surface of the copper powder-filled polytetrafluoroethylene ring (5) is provided with a dynamic seal. The dynamic sealing fitting surface (14) comprises an upper dynamic sealing fitting surface (15), a lower dynamic sealing fitting surface (16) and a middle guide surface (17), the diameter of the upper dynamic sealing fitting surface (15) is larger than the inner diameter of the cylinder body (2) and the difference is 0.5-0.55 mm, the inner diameter of the lower dynamic sealing fitting surface (16) is larger than the diameter of the cylinder body (2) and the difference is 0.5-0.55 mm, and the diameter of the middle guide surface (17) is smaller than the inner diameter of the cylinder body (2). ) and the difference is 0.05-0.1mm; the upper dynamic seal fitting surface (15) is provided with a first inclined surface (18) on a side away from the inner cavity side wall of the cylinder body (2), and the lower dynamic seal fitting surface (16) is provided with a second inclined surface (19) on a side away from the inner cavity side wall of the cylinder body (2), an angle a is provided between the first inclined surface (18) and the piston (1), and an angle b is provided between the second inclined surface (19) and the clamping nut (6), and both a and b are 0.5°.

2. An integrated sealing device for a piston according to claim 1, characterized in that: A first groove (7) is provided between the piston (1) and the metal ring (4), and an O-type sealing ring (8) is provided on the inner surface of the first groove (7).

3. The integrated sealing device for a piston according to claim 1, characterized in that: A rod cavity (9) is provided between the side wall of the piston (1) and the inner cavity of the cylinder body (2), and a rodless cavity (10) is provided between the bottom of the piston (1) and the inner cavity of the cylinder body (2).

4. The integrated sealing device for a piston according to claim 1, characterized in that: The outer surface of the metal ring (4) is provided with a plurality of second grooves (11), the second grooves (11) are equidistantly distributed on the outer surface of the metal ring (4), the distance between the plurality of second grooves (11) is 10 mm, the roughness of the outer surface of the metal ring (4) is 12.5 um, and the roughness of the inner surface of the metal ring (4) is 0.8 um.

5. The integrated sealing device for a piston according to claim 1, characterized in that: The outer surface of the copper powder filled polytetrafluoroethylene ring (5) is provided with a plurality of annular oil grooves (12), the annular oil grooves (12) are evenly distributed on the outer surface of the copper powder filled polytetrafluoroethylene ring (5), and the distance between the plurality of annular oil grooves (12) is 20 mm.

6. The integrated sealing device for a piston according to claim 1, characterized in that: An upper inner cavity (20) is provided between the first inclined surface (18) and the piston (1), and a lower inner cavity (21) is provided between the second inclined surface (19) and the clamping nut (6).

7. The integrated sealing device for a piston according to claim 1, characterized in that: The material of the metal ring (4) is 42 chromium-molybdenum steel.

8. A sealing method for an integrated sealing device for a piston according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, inserting the O-ring (8) into the first groove (7); S2, a metal ring (4) is sleeved on the outer side of the lower part of the piston (1) on which the O-ring (8) is installed; S3, first heating the copper powder filled polytetrafluoroethylene ring (5); then sleeve the heated copper powder filled polytetrafluoroethylene ring (5) on the outside of the metal ring (4); in the process of hot-fitting the copper powder filled polytetrafluoroethylene ring (5) on the outside of the metal ring (4), the hot-fitting bonding surface (13) of the copper powder filled polytetrafluoroethylene ring (5) is closely attached to the metal ring (4), the heating temperature is 165° C.-175° C., and the heating time is 45-55 minutes.

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