Method for non-destructive assembly and rapid recovery of rubber and plastic piston sealing element

Abstract

The invention provides a method for non-destructive assembly and rapid recovery of a rubber and plastic piston sealing element. The method comprises the steps that 1, whether an introduction end chamfer is designed on the inner wall of a sealing element mounting rail or not is determined; 2, heating parameters of the sealing ring are obtained, and the sealing ring is heated based on the heating parameters; 3, a piston sealing piece is installed according to a preset mode; and 4, the sealing ring is restored according to the preset sealing ring shape correcting and restoring requirement. And the product quality of the sealing element in the whole mounting process can be ensured, and the product percent of pass is improved.

Description

Technical Field

[0001] This invention belongs to the field of assembly process technology, and in particular relates to a method for non-destructive assembly and rapid restoration of rubber and plastic piston seals. Background Technology

[0002] Scratches on the assembly seals are highly sensitive to leakage; even minor damage to the hardware or seals can affect sealing performance. Therefore, ensuring the quality of the seals during assembly is crucial. Furthermore, the sealing ring itself has a certain degree of hardness and must be expanded before it can be installed on the piston rod. Simply using brute force to stretch and deform it is time-consuming and laborious, and forcibly stretching it can cause the seal to break. During the stretching process, the stretching band can easily damage the contact surface of the seal, affecting the sealing effect.

[0003] Therefore, there is a need to propose an effective method for installing interference-fit seals into grooves and for ensuring that the seals can be restored to their original shape and size after final installation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is how to install the interference fit seal into the groove and how to ensure that the seal can be restored to its original shape and size after final installation.

[0005] The technical solution of this invention is: A method for non-destructive assembly and rapid restoration of rubber and plastic piston seals includes: Step 1: Determine whether to design a chamfer at the inlet end on the inner wall of the sealing installation track; Step 2: Obtain the heating parameters of the sealing ring, and heat the sealing ring based on these heating parameters; Step 3: Install the piston seal according to the preset method; Step 4: Restore the sealing ring according to the preset sealing ring correction and restoration requirements.

[0006] Optionally, in step 1, if a chamfer is designed on the inner wall of the sealing element mounting track, For the assembly of a single rubber ring, the minimum length ΔDN of the chamfer at the inlet end of the sealing mounting track is determined according to the diameter of the rubber ring's circular cross-section. For the assembly of combined seals, the minimum length ΔDN of the chamfer at the inlet end of the seal mounting track is determined according to the width of the seal mounting groove.

[0007] Optionally, in step 2, the heating parameters for the sealing ring are: the heating temperature in the medium is 80 to 100°C; then the sealing ring is immersed in the oil medium or heated with hot air to 80 to 100°C to soften the sealing ring.

[0008] Optionally, in step 3, when the production batch is small and the seal models are diverse, installation method 1 is used to install the piston seal; when the production batch is large and the seal model is uniform, installation method 2 is used to install the piston seal. Installation method 1: Assembly using non-woven fabric tape: First, install the rubber ring into the piston groove 1, ensuring that the rubber ring is not twisted in the groove 1. Then, insert the sealing ring into the piston inlet end groove 2 and use the non-woven fabric tape to stretch the sealing ring until its entire structure enters the groove 1. Installation method 2: Assembly using a push-in device: First, install the rubber ring into the piston groove 1, ensuring that the rubber ring is not twisted in the groove 1. Then, place the sealing ring on the mounting mandrel, use the push device to hold the sealing ring in place, and push the sealing ring into the groove 1 of the piston rod with the mounting mandrel as a guide.

[0009] Optionally, as the outer diameter of the sealing ring continuously increases as it moves along the mounting mandrel, in order to ensure that it matches the outer diameter of the tapered surface of the mounting mandrel and achieve a state where the diameter changes while maintaining a good fit, the method further includes: designing a slot for the propulsion device.

[0010] Optionally, in step 4, the position of the rubber ring and the sealing ring is adjusted so that the rubber ring is inside the piston groove, and then the sealing ring is pre-shaped for 1 minute using a clamping device so that the sealing ring fits against the inner side of the piston groove. When restoring the sealing ring using the sealing ring mounting track, apply lubricant to the surface of the sealing ring and the mounting track. While rotating, slowly press the sealing ring into the sealing ring mounting track. After the sealing ring fits into the groove, slowly press the sealing ring into the sealing ring mounting track again and adjust for 10-15 minutes.

[0011] Optionally, in step 4, when using the restoration sleeve to restore the sealing ring, apply lubricating oil to the surface of the restoration sleeve and the sealing ring, and slowly press the sealing ring into the restoration sleeve while rotating it. After the sealing ring fits into the groove, adjust it for 10-15 minutes.

[0012] Optionally, the inner diameter of the restoration sleeve is designed according to the inner diameter of the seal mounting track, and the outer diameter of the restoration sleeve is increased by at least 8mm based on the seal mounting track.

[0013] Optionally, if the inner wall of the seal mounting track is not designed with a chamfered inlet end, a guided assembly device is used for assembly. The guided assembly device includes: a seal mounting track, a restoring sleeve, and a piston seal on a rod. The seal mounting track is directly connected to the inner and outer diameters of the restoring sleeve, and the piston seal on the rod is pressed in through the chamfered end of the restoring sleeve. During assembly, the seal mounting track is placed flat on the workbench, and gravity is used to make the seal mounting track fit against the restoring sleeve.

[0014] The beneficial effects of this application are as follows: By rationally designing the surface fit quality of the corresponding seal mounting track before assembly, and providing design parameters and optimal design requirements under various conditions, the paper ensures damage-free assembly of the seal. Furthermore, the paper presents the seal assembly process and assembly parameters, and proposes a rapid shaping and restoration method to guarantee the product quality of the seal throughout the entire installation process, thereby improving the product qualification rate. Attached Figure Description

[0015] Figure 1 Schematic diagram of the chamfer on the inner wall of the mounting rail for the seal; Figure 2 A schematic diagram of a guide assembly device used when the inner wall of the mounting rail for sealing components is designed without chamfering; Figure 3 This is a schematic diagram of the piston seal installation. Figure 4 This is a schematic diagram of a push-in installation. Figure 5 A schematic diagram showing the dimensions for installing the mandrel; Figure 6 This is a schematic diagram of the propulsion device dimensions; Figure 7 This is a diagram illustrating the restoration and installation process; Figure 8 This is a schematic diagram of the restored sleeve.

[0016] Among them, 1-sealing installation track, 2-restoring sleeve, 3-piston seal on rod, 41-propulsion device, 42-sealing ring, 43-installation mandrel, 44-rubber ring, 71-restoring sleeve. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0019] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited from each other.

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0021] This invention provides a method for the non-destructive assembly and rapid restoration of rubber and plastic piston seals, comprising the following steps: Step 1: Improve the design requirements for the seal mounting track.

[0022] The piston seal on the rod is typically installed into the inner hole of the seal mounting track using a press-fit method. From an assembly perspective, to avoid damaging the piston seal during assembly, a chamfer is designed on the inlet end and sharp edges are rounded off on the inner wall of the seal mounting track. See [link to assembly instructions]. Figure 1 Based on experimental data, for the assembly of a single rubber ring, the minimum length ΔDN of the chamfer at the inlet end of the seal mounting track can be determined according to the diameter of the rubber ring's circular cross-section; detailed dimensions can be found in Table 1. For the assembly of combined seals, the minimum length ΔDN of the chamfer at the inlet end of the seal mounting track can be determined according to the width of the seal mounting groove.

[0023] Table 1 Recommended values ​​for the minimum chamfer length ΔDN at the lead end (unit: mm)

[0024] If, due to design reasons, there is no chamfer at the lead-in end, a guided assembly device is required; see [link to relevant documentation]. Figure 2 The assembly guide includes: a seal mounting track 1, a return sleeve 2, and a piston seal 3 on a rod. The seal mounting track 1 directly mates with the inner and outer diameters of the return sleeve 2, and the piston seal 3 on the rod is pressed in through the chamfered end of the return sleeve 2. During assembly, the seal mounting track 1 is placed flat on the worktable, and gravity is used to make the seal mounting track 1 fit against the return sleeve 2.

[0025] The guide assembly device is mainly used when the seal installation track has no chamfer, so as to protect the piston seal on the rod from damage during assembly.

[0026] Step 2: Obtain the heating parameters of the sealing ring, and heat the sealing ring based on the heating parameters.

[0027] Taking into account the sealing ring's temperature resistance and high tensile strength, the heating parameters for the sealing ring are obtained: the heating temperature in the medium is 80 to 100℃.

[0028] The sealing ring is softened by immersing it in oil or by blowing hot air and heating it to 80 to 100°C.

[0029] Step 3: Install the piston seal.

[0030] Considering ease of installation and production efficiency, two installation methods for piston seals are designed. When the production batch is small or the seal model is diverse, installation method 1 is adopted. When the production batch is large and the seal model is uniform, installation method 2 is adopted.

[0031] Installation Method 1: Assembly using non-woven fabric tape: First, install the rubber ring into the piston groove 1, ensuring that the rubber ring is not twisted in the groove 1. Figure 3 As shown. Next, insert the sealing ring into the piston inlet groove 2. Use a non-woven fabric tape to stretch the sealing ring until its entire structure is inserted into groove 1. The non-woven fabric tape must be free of lint or other debris to avoid soiling the seal.

[0032] Installation Method 2: Assembly using a push-in device: First, install the rubber ring into the piston groove 1, ensuring that the rubber ring is not twisted in the groove 1. Figure 4 As shown, place the sealing ring 42 on the mounting mandrel 43, use the pushing device 41 to hold the sealing ring in place, pay attention to the installation direction of the sealing ring, and quickly push the pushing device 41 to push the sealing ring 42 into the groove 1 of the piston rod with the mounting mandrel 43 as the guide.

[0033] The push-in device includes a propulsion device 41 and a mounting spindle 43, wherein the propulsion device 41 is used to apply thrust to the sealing ring 42, and the mounting spindle 43 is used to guide the movement of the sealing ring 42. The structures of the propulsion device 41 and the mounting spindle 43 are shown below. Figure 5 and Figure 6 Ensure the mounting mandrel is burr-free, smooth, and rounded to prevent scratching the sealing ring.

[0034] Because the sealing ring is along such Figure 5As the mounting mandrel moves, its outer diameter continuously increases. To ensure that it matches the outer diameter of the mounting mandrel's conical surface and achieves a state where the diameter changes while maintaining a good fit, the propulsion device 41 needs to be designed with a slot.

[0035] Step 4: After installing the piston seal, restore the sealing ring according to the preset sealing ring alignment and restoration requirements.

[0036] Manually adjust the position of the rubber ring and the sealing ring so that the rubber ring is inside the piston groove. Then use a clamping device to pre-shape the sealing ring for 1 minute so that the sealing ring fits against the inside of the piston groove.

[0037] Use the appropriate seal mounting track to restore the installed sealing ring. Apply lubricant to the surface of the seal mounting track and the sealing ring, and slowly press the sealing ring into the seal mounting track while rotating it. Observe the state of the sealing ring during pressing. If it is squeezed out, adjust the sealing ring manually or with a general tool to ensure that it fits the groove. Then slowly press the sealing ring into the seal mounting track and adjust it for 10-15 minutes.

[0038] If the corresponding sealing mounting track does not meet the chamfer requirements of the inlet end as specified in Table 1, a restoring sleeve is required to restore the sealing ring. During restoration, apply lubricating oil to the surfaces of the restoring sleeve 71 and the sealing ring 42, and slowly press the sealing ring into the restoring sleeve while rotating it. Figure 7 As shown, observe the state of the sealing ring during pressing. If it is squeezed out, manually or with a general-purpose tool adjust the sealing ring to ensure it fits the groove. Then, adjust the shape for 10-15 minutes. The design dimensions of the recovery sleeve 71 are shown below. Figure 8 .

[0039] The recovery sleeve is typically made of polyoxymethylene, nylon, or other similar materials, with a smooth surface and no sharp edges that could damage the seal. The inner diameter of the recovery sleeve is designed according to the inner diameter of the seal mounting rail, and the outer diameter is at least 8mm larger than the seal mounting rail. The length is not limited.

[0040] The above description merely illustrates embodiments of the present invention and is quite specific and detailed; however, it should not be construed as limiting the scope of the patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Furthermore, any parts of the present invention not described in detail are conventional techniques.

Claims

1. A method for non-destructive assembly and rapid restoration of rubber and plastic piston seals, characterized in that, include: Step 1: Determine whether to design a chamfer at the inlet end on the inner wall of the sealing installation track; Step 2: Obtain the heating parameters of the sealing ring, and heat the sealing ring based on these heating parameters; Step 3: Install the piston seal according to the preset method; Step 4: Restore the sealing ring according to the preset sealing ring correction and restoration requirements.

2. The method as described in claim 1, characterized in that, In step 1, if a chamfer is designed on the inner wall of the sealing installation track, For the assembly of a single rubber ring, the minimum length ΔDN of the chamfer at the inlet end of the sealing mounting track is determined according to the diameter of the rubber ring's circular cross-section. For the assembly of combined seals, the minimum length ΔDN of the chamfer at the inlet end of the seal mounting track is determined according to the width of the seal mounting groove.

3. The method as described in claim 1, characterized in that, In step 2, the heating parameters for the sealing ring are as follows: the heating temperature in the medium is 80 to 100°C; then the sealing ring is immersed in the oil medium or heated with hot air to 80 to 100°C to soften the sealing ring.

4. The method as described in claim 1, characterized in that, In step 3, when the production batch is small and the seal models are diverse, installation method 1 is used to install the piston seal; when the production batch is large and the seal model is uniform, installation method 2 is used to install the piston seal. Installation method 1: Assembly using non-woven fabric tape: First, install the rubber ring into the piston groove 1, ensuring that the rubber ring is not twisted in the groove 1. Then, insert the sealing ring into the piston inlet end groove 2 and use the non-woven fabric tape to stretch the sealing ring until its entire structure enters the groove 1. Installation method 2: Assembly using a push-in device: First, install the rubber ring into the piston groove 1, ensuring that the rubber ring is not twisted in the groove 1. Then, place the sealing ring on the mounting mandrel, use the push device to hold the sealing ring in place, and push the sealing ring into the groove 1 of the piston rod with the mounting mandrel as a guide.

5. The method as described in claim 4, characterized in that, The method also includes: slotting the propulsion device.

6. The method as described in claim 1, characterized in that, In step 4, adjust the position of the rubber ring and the sealing ring so that the rubber ring is inside the piston groove. Then use a clamping device to pre-shape the sealing ring for 1 minute so that the sealing ring fits against the inside of the piston groove. When restoring the sealing ring using the sealing ring mounting track, apply lubricant to the surface of the sealing ring and the mounting track. While rotating, slowly press the sealing ring into the sealing ring mounting track. After the sealing ring fits into the groove, slowly press the sealing ring into the sealing ring mounting track again and adjust for 10-15 minutes.

7. The method as described in claim 6, characterized in that, In step 4, when using the restoration sleeve to restore the sealing ring, apply lubricating oil to the surface of the restoration sleeve and the sealing ring. While rotating, slowly press the sealing ring into the restoration sleeve. After the sealing ring fits into the groove, adjust the shape for 10-15 minutes.

8. The method as described in claim 7, characterized in that, The inner diameter of the restoration sleeve is designed based on the inner diameter of the seal mounting track, and the outer diameter of the restoration sleeve is increased by at least 8mm based on the seal mounting track.

9. The method as described in claim 2, characterized in that, If the inner wall of the seal mounting track is not designed with a chamfered inlet end, a guided assembly device is used for assembly. The guided assembly device includes: a seal mounting track, a return sleeve, and a piston seal on a rod. The seal mounting track and the return sleeve are directly connected in the inner and outer diameters. The piston seal on the rod is pressed in through the chamfered end of the return sleeve. During assembly, the seal mounting track is placed flat on the workbench, and gravity is used to make the seal mounting track fit against the return sleeve.

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