Assembling process of pressure limiting valve assembly and pressure limiting valve assembly

Abstract

The present invention provides an assembly process of a pressure-limiting valve assembly and a pressure-limiting valve assembly. The assembly process of the pressure-limiting valve assembly includes: using a magnetron sputtering coating process to coat a protective coating on the surface of an iron ball; pressing the iron ball coated with the protective coating into a valve core seat by cold working to form a pressure-limiting valve core; injecting a plastic valve body and an iron core into a valve body by an insert injection molding process; injecting the pressure-limiting valve core and the valve body into one piece by an insert injection molding process to form a pressure-limiting valve; and sleeve a plastic valve sleeve on the outside of the pressure-limiting valve to form a pressure-limiting valve assembly. The present invention solves the problem in the prior art that the pressure-limiting valve assembly is very likely to cause wear to the steel ball core during the assembly process.

Description

Technical Field

[0001] The present invention relates to the technical field of household electrical appliances, and in particular to an assembly process of a pressure limiting valve assembly and the pressure limiting valve assembly. Background Art

[0002] At present, the pressure limiting device on the electric pressure cooker mostly uses a steel ball core and an aluminum exhaust pipe with surface oxidation treatment to achieve the connection between the electric pressure cooker and the outside atmosphere. However, the electric pressure cooker needs to be sealed during operation, and the surface finish of the steel ball core is relatively high. The existing steel ball core needs to be welded to the ball valve handle after grinding. During welding, a lot of heat is generated, which will affect the profile and finish of the steel ball core surface. In addition, the welding machine precision requirements are high, and the investment cost of welding equipment is high.

[0003] That is to say, in the prior art, the pressure limiting valve assembly has the problem of easily causing wear to the steel ball core during the assembly process. Summary of the invention

[0004] The main purpose of the present invention is to provide an assembly process of a pressure-limiting valve assembly and a pressure-limiting valve assembly, so as to solve the problem in the prior art that the pressure-limiting valve assembly is very likely to cause wear to the steel ball core during the assembly process.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, an assembly process of a pressure-limiting valve assembly is provided, comprising: coating a protective coating on the surface of an iron ball by a magnetron sputtering coating process; pressing the iron ball coated with the protective coating into a valve core seat by cold working to form a pressure-limiting valve core; injection molding a plastic valve body and an iron core into a valve body by an insert injection molding process; injection molding the pressure-limiting valve core and the valve body into one piece by an insert injection molding process to form a pressure-limiting valve; and sleeveing ​​a plastic valve sleeve on the outside of the pressure-limiting valve to form a pressure-limiting valve assembly.

[0006] A protective coating is applied to the surface of the iron ball by a magnetron sputtering coating process to increase the strength of the surface of the iron ball and reduce the wear on the surface of the iron ball. The iron ball coated with the protective coating is pressed into the valve core seat by cold working. The cold working method does not damage the surface finish and contour of the iron ball, thus reducing the wear on the iron ball. In addition, the cold working method only requires conventional punching equipment, which requires less equipment investment and saves production costs. The valve core and valve body of the pressure limiting valve are processed into a pressure limiting valve by an injection molding process. The tightness of the connection between the valve core and the valve body of the pressure limiting valve makes it difficult for the valve core and the valve body of the pressure limiting valve to separate.

[0007] Furthermore, the protective coating is a titanium nitride layer. The titanium nitride layer can increase the hardness of the surface of the iron ball, extend the service life of the iron ball, and thus increase the service life of the pressure limiting valve assembly. The titanium nitride layer is relatively stable and not easily worn, so that the iron ball can stably seal the exhaust pipe.

[0008] Furthermore, plating a protective coating on the surface of the iron ball includes the following steps: step S11, vacuuming the magnetron sputtering coating machine; step S12, sending the iron ball into the magnetron sputtering coating machine; step S13, introducing nitrogen and argon into the magnetron sputtering coating machine; step S14, supplying power with a DC power supply, ionizing the nitrogen to ionize electrons and nitrogen ions, the electrons will fly to the anode, and the nitrogen ions will fly to the target material of the cathode to bombard the target material, the target material will be sputtered, titanium particles and secondary electrons will be knocked out, and the titanium particles will reach the surface of the iron ball and react with the nitrogen ions to form a titanium nitride layer. The magnetron sputtering coating machine is vacuumed to stabilize the environment inside the magnetron sputtering coating machine in preparation for plating a titanium nitride layer on the iron ball. Since argon is an inert gas, the pressure of the internal environment of the magnetron sputtering coating machine can be controlled by controlling the amount of argon introduced. Nitrogen provides raw materials for plating a titanium nitride layer on the surface of the iron ball. Under the action of voltage, the nitrogen is ionized and electrons and nitrogen ions are ionized. The nitrogen ions bombard the target material, causing the target material to be sputtered, forming a titanium nitride layer on the surface of the iron ball.

[0009] Furthermore, in step S11, the preset pressure of the magnetron sputtering coating machine is greater than or equal to 1.0*10 -3 Pa and less than or equal to 3.0*10 -3 Pa to achieve vacuum. When the pressure in the magnetron sputtering coating machine is 1.0*10 -3 Pa to 3.0*10 -3 When the pressure is within the Pa range, the iron ball is sent to the magnetron sputtering coating machine.

[0010] Further, in step S12, the working pressure of the magnetron sputtering coating machine is greater than or equal to 0.2 Pa and less than or equal to 1.2 Pa. After the iron ball is delivered to the magnetron sputtering coating machine, nitrogen and argon are introduced into the magnetron sputtering coating machine so that the pressure in the magnetron sputtering coating machine is between 0.2 Pa and 1.2 Pa. The working pressure of the magnetron sputtering coating machine between 0.2 Pa and 1.2 Pa is conducive to the ionization of nitrogen.

[0011] Furthermore, in step S13, the flow rate of nitrogen gas is greater than or equal to 1.0 cm 3 / min and less than or equal to 3.0cm 3 / min; and / or in step S13, the flow rate of argon gas is greater than or equal to 15cm 3 / min and less than or equal to 35cm 3 / min. This setting makes the nitrogen gas within a certain concentration so that the nitrogen gas can be well ionized and a titanium nitride layer can be stably formed on the surface of the iron ball. Limiting the nitrogen and argon gas to a certain ratio can also reduce safety hazards.

[0012] Further, the iron ball is a substrate, and in step S14, after the DC power supply is powered, the substrate bias voltage of the substrate is greater than or equal to 0 V and less than or equal to 200 V. The substrate bias voltage is set within the range of 0 V to 200 V, so that titanium ions can be accelerated to fly toward the substrate to form a titanium nitride layer on the surface of the iron ball.

[0013] Further, in step S14, the substrate temperature of the substrate is greater than or equal to 20° C. and less than or equal to 400° C. In this temperature range, it is favorable for nitrogen ions to react with titanium ions to form a titanium nitride layer on the surface of the iron ball.

[0014] Furthermore, the target material is pure titanium or titanium alloy. This arrangement allows titanium ions to be sputtered out to react with nitrogen ions.

[0015] Furthermore, the thickness of the protective coating is greater than or equal to 40 microns and less than or equal to 50 microns. Setting the thickness of the protective coating within the range of 40 microns to 50 microns does not significantly increase the diameter of the iron ball, and can also ensure the hardness of the protective coating to increase the sealing effect.

[0016] According to another aspect of the present invention, a pressure-limiting valve assembly is provided. The pressure-limiting valve assembly is manufactured using the above-mentioned assembly process of the pressure-limiting valve assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0018] Figure 1 A schematic diagram showing the overall structure of a pressure limiting valve of a cooking appliance according to an optional embodiment of the present invention; and

[0019] Figure 2 Shows Figure 1 Exploded diagram of

[0020] Figure 3 Shows Figure 1 Schematic diagram of the structure of Sinosteel ball core.

[0021] The above drawings include the following reference numerals:

[0022] 10. Iron ball; 20. Valve core seat; 21. Connecting section; 22. Clamping section; 23. Groove; 30. Plastic valve sleeve; 41. Plastic valve body; 42. Iron core; 411. Annular spacer rib; 50. Protective coating. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0025] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0026] In order to solve the problem in the prior art that a steel ball core is easily worn during the assembly of a pressure-limiting valve assembly, the present invention provides an assembly process of a pressure-limiting valve assembly and a pressure-limiting valve assembly.

[0027] like Figures 1 to 3 As shown, the assembly process of the pressure-limiting valve assembly includes: using a magnetron sputtering coating process to coat a protective coating 50 on the surface of the iron ball 10; pressing the iron ball 10 coated with the protective coating 50 into the valve core seat 20 through cold working to form a pressure-limiting valve core; injecting the plastic valve body 41 and the iron core 42 into a valve body through an insert injection molding process; injecting the pressure-limiting valve core and the valve body into one piece through an insert injection molding process to form a pressure-limiting valve; and sleeve a plastic valve sleeve 30 on the outside of the pressure-limiting valve to form a pressure-limiting valve assembly.

[0028] A protective coating 50 is plated on the surface of the iron ball 10 by a magnetron sputtering coating process to increase the strength of the surface of the iron ball 10 and reduce the wear on the surface of the iron ball 10. The iron ball 10 plated with the protective coating 50 is pressed into the valve core seat 20 by cold working. The cold working method does not destroy the surface finish of the iron ball 10 and the contour of the surface of the iron ball 10, thereby reducing the wear on the iron ball 10. In addition, the cold working method only requires conventional punching equipment, which requires less equipment investment and saves production costs. The valve core and valve body of the pressure limiting valve are processed into a pressure limiting valve by an injection molding process. The tightness of the connection between the valve core and the valve body of the pressure limiting valve makes it difficult for the valve core and the valve body of the pressure limiting valve to separate.

[0029] It should be noted that the iron core 42 is used as a counterweight, and the weight can be adjusted according to actual needs. According to the pressure formula P=F / S, it can be known that if you want to adjust the control pressure, under the condition that the contact surface remains unchanged, the pressure can only be adjusted by externally adjusting the external force. According to the force analysis, it can be known that the weight mg borne by the pressure-limiting valve assembly is F. By adjusting the weight of the pressure-limiting valve assembly, the pressure regulation of the entire system can be achieved. In order to achieve weight adjustment, the iron core 42 and the plastic valve body 41 are set. The iron core 42 is a turning pin. By adjusting the weight of the iron core 42, the weight of the entire pressure-limiting valve assembly can be changed, thereby achieving pressure control adjustment.

[0030] Optionally, the protective coating 50 is a titanium nitride layer. The titanium nitride layer can increase the hardness of the surface of the iron ball 10, extend the service life of the iron ball 10, and thus increase the service life of the pressure limiting valve assembly. The titanium nitride layer is relatively stable and not easily worn, so that the iron ball 10 can stably seal the exhaust pipe.

[0031] Plating a protective coating 50 on the surface of the iron ball 10 includes the following steps: step S11, vacuuming the magnetron sputtering coating machine; step S12, sending the iron ball 10 into the magnetron sputtering coating machine; step S13, introducing nitrogen and argon into the magnetron sputtering coating machine; step S14, supplying power with a DC power supply, ionizing the nitrogen to ionize electrons and nitrogen ions, the electrons will fly to the anode, and the nitrogen ions will fly to the target material at the cathode to bombard the target material, the target material will be sputtered, titanium particles and secondary electrons will be knocked out, and the titanium particles will reach the surface of the iron ball 10 and react with the nitrogen ions to form a titanium nitride layer. The magnetron sputtering coating machine is vacuumed to stabilize the environment inside the magnetron sputtering coating machine in preparation for plating a titanium nitride layer on the iron ball 10. Since argon is an inert gas, the pressure of the internal environment of the magnetron sputtering coating machine can be controlled by controlling the amount of argon introduced. Nitrogen provides raw materials for plating a titanium nitride layer on the surface of the iron ball 10. Under the action of the voltage, the nitrogen gas is ionized and electrons and nitrogen ions are ionized. The nitrogen ions bombard the target material, so that the target material is sputtered, and a titanium nitride layer is formed on the surface of the iron ball 10 .

[0032] In step S11, the preset pressure of the magnetron sputtering coating machine is greater than or equal to 1.0*10 -3 Pa and less than or equal to 3.0*10 -3 Pa to achieve vacuum. When the pressure in the magnetron sputtering coating machine is 1.0*10 -3 Pa to 3.0*10 -3 When the pressure is within the range of Pa, the iron ball 10 is sent to the magnetron sputtering coating machine.

[0033] It should be noted that in this application, when the pressure in the magnetron sputtering coating machine is greater than or equal to 1.0*10 -3 Pa and less than or equal to 3.0*10 -3Pa is considered as a vacuum.

[0034] In step S12, the working pressure of the magnetron sputtering coating machine is greater than or equal to 0.2 Pa and less than or equal to 1.2 Pa. After the iron ball 10 is delivered to the magnetron sputtering coating machine, nitrogen and argon are introduced into the magnetron sputtering coating machine to make the pressure in the magnetron sputtering coating machine between 0.2 Pa and 1.2 Pa. The working pressure of the magnetron sputtering coating machine between 0.2 Pa and 1.2 Pa is conducive to the ionization of nitrogen.

[0035] In step S13, the flow rate of nitrogen is greater than or equal to 1.0 cm 3 / min and less than or equal to 3.0cm 3 / min; and / or in step S13, the flow rate of argon gas is greater than or equal to 15cm 3 / min and less than or equal to 35cm 3 / min. This arrangement allows the nitrogen to be within a certain concentration so that the nitrogen can be well ionized, so that a titanium nitride layer can be stably formed on the surface of the iron ball 10. Limiting the nitrogen and argon gases to a certain ratio can also reduce safety hazards.

[0036] In the present application, the iron ball 10 is a substrate, and in step S14, after the DC power supply is powered, the substrate bias voltage of the substrate is greater than or equal to 0 V and less than or equal to 200 V. The substrate bias voltage is set within the range of 0 V to 200 V, so that titanium ions can be accelerated to fly toward the substrate to form a titanium nitride layer on the surface of the iron ball 10.

[0037] Specifically, in step S14 , the substrate temperature of the substrate is greater than or equal to 20° C. and less than or equal to 400° C. Within this temperature range, nitrogen ions and titanium ions are favorable to react to form a titanium nitride layer on the surface of the iron ball 10 .

[0038] Optionally, the target material is pure titanium or a titanium alloy. This arrangement allows titanium ions to be sputtered out to react with nitrogen ions.

[0039] Specifically, the thickness of the protective coating 50 is greater than or equal to 40 microns and less than or equal to 50 microns. Setting the thickness of the protective coating 50 within the range of 40 microns to 50 microns does not significantly increase the diameter of the iron ball 10, and can also ensure the hardness of the protective coating 50 to increase the sealing effect.

[0040] It should be noted that the iron ball 10 mentioned above can also be a carbon steel ball or a stainless steel ball.

[0041] The iron ball 10 can be a standardized steel ball for ball bearings in large quantities on the current market to reduce procurement costs.

[0042] The principle of sputtering coating is that the plasma generated by the anomalous glow discharge of rarefied gas bombards the outer surface of the cathode target under the effect of the electric field, sputtering out the molecules, atoms, ions and electrons on the outer surface of the target. The sputtered particles carry a certain kinetic energy and are ejected toward the surface of the substrate under the action of the electric field, forming a coating on the surface of the substrate.

[0043] Magnetron sputtering is developed on the basis of dipole sputtering. It establishes a magnetic field orthogonal to the electric field on the outer surface of the target material, which solves the problems of low deposition rate and low plasma rate of dipole sputtering and becomes one of the primary methods in the current coating industry. Compared with other coating technologies, magnetron sputtering has the following characteristics: a large number of materials can be prepared into targets, and it can be said that all metals can be used as targets, and alloys and ceramic materials can be made into targets; under appropriate conditions, multi-target co-sputtering can also be achieved, and alloys with accurate and stable proportions can be deposited; adding oxygen, nitrogen or other active gases to the discharge atmosphere of magnetron sputtering can deposit a compound film of target material and gas molecules; by accurately controlling the process of magnetron sputtering coating, a uniform and high-precision film thickness can be obtained; after ion sputtering, the target material is directly transformed from solid to plasma state. In the magnetron sputtering environment, the installation of the target material is not restricted, and it can be applied to the multi-target layout design of large-volume coating chambers; magnetron sputtering coating has the advantages of fast speed, fine film layer, good adhesion, etc., which is very suitable for large-scale and high-efficiency industrial production.

[0044] Optionally, the valve core seat 20 is made of aluminum material, which facilitates pressing the iron ball 10 into the valve core seat 20 .

[0045] like Figure 1 and Figure 2 As shown, the valve core seat 20 has a connecting section 21 and a clamping section 22, and the clamping section 22 has a groove 23. The iron ball 10 is pressed into the groove 23 by cold working. The setting of the groove 23 allows the iron ball 10 to be clamped in the groove 23, and the iron ball 10 and the groove 23 are interference fit to reduce the risk of the iron ball 10 being separated from the valve core seat 20, and greatly increase the stability of the connection between the iron ball 10 and the valve core seat 20.

[0046] like Figure 1 and Figure 2 As shown, the groove wall of the groove 23 shrinks inwardly in a direction away from the groove bottom to clamp the iron ball 10. The groove wall of the groove 23 shrinks inwardly in a direction away from the groove bottom so that the opening of the groove 23 has a certain deformation, which facilitates pressing the iron ball 10 into the groove 23, making the process of pressing the iron ball 10 into the valve core seat 20 simpler.

[0047] like Figure 1 and Figure 2As shown, the pressure limiting valve assembly also includes a plastic valve sleeve 30, the valve core seat 20 is snap-connected with the plastic valve sleeve 30, and the plastic valve sleeve 30 has an exhaust hole, and the gas exhausted from the exhaust pipe is discharged from the exhaust hole. The connecting section 21 is snapped into the plastic valve sleeve 30 to connect the valve core seat 20 with the plastic valve sleeve 30, and the snap connection greatly increases the tightness of the connection between the valve core seat 20 and the plastic valve sleeve 30. The setting of the exhaust hole allows the cooking utensil to quickly discharge gas when performing a pressure relief and exhaust operation, and the gas will not accumulate at the pressure limiting valve assembly, thereby reducing the influence of humid gas on the iron ball 10 and increasing the service life of the iron ball 10.

[0048] like Figure 1 and Figure 2 As shown, the pressure limiting valve assembly also includes a valve body, which includes a plastic valve body 41 and an iron core 42. The iron core 42 is embedded in the plastic valve body 41, and the iron core 42 can adjust the counterweight of the pressure limiting valve assembly. The matching form of the iron core 42 and the plastic valve body 41 enables the pressure limiting valve assembly to be used in cooking utensils with various pressure conditions. When assembling the pressure limiting valve assembly, it is only necessary to install iron cores 42 of different weights to make the pressure limiting valve assembly suitable for cooking utensils with different pressure requirements, without the need to set pressure limiting valve assemblies or valve bodies of different specifications, which greatly increases the versatility of the valve body.

[0049] like Figure 1 As shown, the plastic valve body 41 includes an annular rib 411, which is spaced apart from the edge of the plastic valve body 41 to form a receiving groove, and the iron core 42 is located in the receiving groove. The area between the annular rib 411 and the center of the plastic valve body 41 is a central through hole, and the exhaust pipe is located at the central through hole. The setting of the annular rib 411 can reduce the influence of the hot air discharged from the exhaust pipe on the iron core 42, and greatly increase the working stability of the iron core 42.

[0050] Specifically, the iron core 42 is a turned pin part.

[0051] The pressure-limiting valve assembly manufactured by the above-mentioned assembly process of the pressure-limiting valve assembly has the characteristic of being not easy to wear.

[0052] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0053] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0054] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An assembly process for a pressure limiting valve assembly, characterized in that: include: A protective coating (50) is plated on the surface of the iron ball (10) by using a magnetron sputtering coating process; The iron ball (10) coated with the protective coating (50) is pressed into the valve core seat (20) by cold working to form a valve core of the pressure limiting valve; The plastic valve body (41) and the iron core (42) are injection molded into a valve body through an insert injection molding process; The valve core of the pressure-limiting valve and the valve body are molded into one piece by an insert injection molding process to form a pressure-limiting valve; A plastic valve sleeve (30) is sleeved on the outside of the pressure-limiting valve to form a pressure-limiting valve assembly, and the valve core seat (20) is clamped with the plastic valve sleeve (30).

2. The assembly process of the pressure limiting valve assembly according to claim 1, characterized in that: The protective coating (50) is a titanium nitride layer.

3. The assembly process of the pressure limiting valve assembly according to claim 2, characterized in that: Plating the protective coating (50) on the surface of the iron ball (10) comprises the following steps: Step S11, evacuating the magnetron sputtering coating machine; Step S12, sending the iron ball (10) into the magnetron sputtering coating machine; Step S13, introducing nitrogen and argon into the magnetron sputtering coating machine; Step S14, a DC power supply is supplied, the nitrogen is ionized to generate electrons and nitrogen ions, the electrons fly to the anode, and the nitrogen ions fly to the target material at the cathode to bombard the target material, the target material is sputtered, titanium particles and secondary electrons are ejected, and the titanium particles reach the surface of the iron ball (10) and react with the nitrogen ions to form the titanium nitride layer.

4. The assembly process of the pressure limiting valve assembly according to claim 3, characterized in that: In step S11, the preset pressure of the magnetron sputtering coating machine is greater than or equal to 1.0*10 -3 Pa and less than or equal to 3.0*10 -3 Pa, to achieve the vacuuming.

5. The assembly process of the pressure limiting valve assembly according to claim 3, characterized in that: In the step S12, the working pressure of the magnetron sputtering coating machine is greater than or equal to 0.2Pa and less than or equal to 1.2Pa.

6. The assembly process of the pressure limiting valve assembly according to claim 3, characterized in that: In step S13, the flow rate of the nitrogen gas is greater than or equal to 1.0 cm 3 / min and less than or equal to 3.0cm 3 / min; and / or In step S13, the flow rate of the argon gas is greater than or equal to 15 cm 3 / min and less than or equal to 35cm 3 / min.

7. The assembly process of the pressure limiting valve assembly according to claim 3, characterized in that: The iron ball (10) is a substrate. In the step S14, after the DC power supply is powered, the substrate bias voltage of the substrate is greater than or equal to 0 volt and less than or equal to 200 volts.

8. The assembly process of the pressure limiting valve assembly according to claim 7, characterized in that: In the step S14, the substrate temperature of the substrate is greater than or equal to 20°C and less than or equal to 400°C.

9. The assembly process of the pressure limiting valve assembly according to any one of claims 3 to 8, characterized in that: The target material is pure titanium or titanium alloy.

10. The assembly process of the pressure limiting valve assembly according to any one of claims 1 to 8, characterized in that: The thickness of the protective coating (50) is greater than or equal to 40 micrometers and less than or equal to 50 micrometers.

11. A pressure limiting valve assembly, characterized in that: The pressure-limiting valve assembly is manufactured by using the assembly process of the pressure-limiting valve assembly according to any one of claims 1 to 10.

Images