Manufacturing method of electromagnetic valve

Abstract

The invention provides a manufacturing method of an electromagnetic valve, the electromagnetic valve comprises a sleeve, a valve seat, a static core and a movable core, the static core and the movable core are oppositely arranged in the axial direction, at least part of the static core and at least part of the movable core are located in the sleeve, an annular groove is formed in the upper end face of the valve seat, and the annular groove is formed in the lower end face of the valve seat. An annular groove is formed in the valve seat, a containing cavity for containing welding flux is defined by the annular groove and the sleeve, the sleeve and the valve seat are made of different materials, and the method comprises the following steps that the sleeve is inserted into the valve seat; a welding wire is conveyed to the position of the annular groove, a laser beam is emitted to the welding wire at the position of the annular groove, and laser welding is conducted; and the welded sleeve and valve seat are assembled with other parts of the electromagnetic valve to form the electromagnetic valve. According to the scheme, the valve seat and the sleeve which are made of different materials are connected through laser welding, and cost can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of valve manufacturing, and in particular to a method for manufacturing a solenoid valve. Background Art

[0002] The solenoid valve includes a matching moving core and a stationary core, which are distributed axially. The solenoid valve also includes a sleeve and a valve seat. The lower end of the sleeve is connected to the valve seat. The sleeve is sleeved around the outer periphery of the stationary core and the moving core, and can be press-fitted and fixed with the stationary core. Both the moving core and the stationary core can be partially located in the sleeve. The sleeve is used to protect the internal stationary core and the moving core. A coil assembly is sleeved on the outer periphery of the sleeve. The coil assembly is powered on or off to control the stationary core to generate magnetism to attract the moving core or lose magnetism to move away from the moving core, thereby driving the valve core of the solenoid valve to open or close the valve port. In the existing structure, the sleeve and the valve seat are both made of stainless steel, and the cost of such a solenoid valve is relatively high. Summary of the invention

[0003] The purpose of the present application is to provide a method for manufacturing a solenoid valve, which can reduce costs by connecting a valve seat and a sleeve made of different materials through laser welding.

[0004] The present application provides a method for manufacturing a solenoid valve, the solenoid valve comprising a sleeve, a valve seat, a static core and a dynamic core, the static core and the dynamic core being arranged opposite to each other in the axial direction, at least a portion of the static core and at least a portion of the dynamic core being located in the sleeve, an annular groove being provided on the upper end surface of the valve seat, the annular groove and the sleeve enclosing a receiving cavity for receiving solder, the sleeve and the valve seat being made of different materials, the method comprising the following steps:

[0005] inserting the sleeve into the valve seat;

[0006] Delivering a welding wire to the position of the annular groove, and emitting a laser beam to the welding wire at the position of the annular groove to perform laser welding;

[0007] The welded sleeve and the valve seat are assembled with other components of the solenoid valve to form the solenoid valve.

[0008] In the present application, the valve seat and the sleeve are welded and fixed by laser welding, so the valve seat and the sleeve can be made of different materials, which is conducive to selecting materials according to needs and has low cost. For example, the sleeve is made of stainless steel and the valve seat is made of aluminum alloy, which has the characteristics of corrosion resistance and light weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a schematic diagram of the structure of the solenoid valve in the embodiment of the present application;

[0010] Figure 2 for Figure 1 A cross-sectional view of the solenoid valve along the AA direction;

[0011] Figure 3 for Figure 2 Schematic diagram of the connection between the middle casing and the valve seat;

[0012] Figure 4 for Figure 3 An enlarged view of the connection between the middle casing and the valve seat;

[0013] Figure 5 A schematic diagram of another method of assembling the valve seat and the lower end of the sleeve in an embodiment of the present application;

[0014] Figure 6 for Figure 5 Enlarged view of the B area;

[0015] Figure 7 for Figure 6 Enlarged view of the location of the annular gap between the center valve seat and the sleeve.

[0016] The symbols in the above drawings are explained as follows:

[0017] 01. Solenoid valve; 01a. Annular seam; 1. Screw assembly; 2. Coil assembly; 3. Valve body; 4. Valve seat; 4a. Annular groove; 4b. Mounting hole; 41. Step surface; 42. Hole wall; 421. First hole wall section; 422. Second hole wall section; 5. Valve core; 6. Moving core; 7. Sealing block; 8. Limiting pad; 9. Sealing ring; 10. Sealing pad; 11. First spring; 12. Sleeve; 13. Second spring; 14. Stationary core; 02. Welding wire. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0019] Please refer to Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of the structure of the solenoid valve in the embodiment of the present application; Figure 2 for Figure 1 Cross-sectional view of the solenoid valve along the AA direction.

[0020] The solenoid valve 01 includes a sleeve 12 and a valve seat 4. The lower end surface of the sleeve 12 abuts against the valve seat 4 in the axial direction. The static core 14 and the dynamic core 6 are arranged in the sleeve 12 and the valve seat 4 in an axially opposite manner. The static core 14 is located above the dynamic core 6, and the upper and lower directions are defined in the axial direction with reference to this. The outer periphery of the sleeve 12 is provided with a coil assembly 2, and the coil assembly 2 can be fixed together with the static core 14 by a screw assembly 1. The solenoid valve 01 also includes a valve body 3, which is connected to the valve seat 4. Figure 2The valve body 3 and the valve seat 4 are threadedly connected, a valve core 5 is provided in the valve body 3, a sealing gasket 10 is provided at the lower end of the valve core 5, and the sealing gasket 10 is used to cooperate with the valve port provided in the valve body 3 to close or open the valve port. The valve core 5 is also provided with a limit gasket 8 for limiting the sealing gasket 10. A sealing ring 9 is provided between the valve core 5 and the valve seat 4 to achieve sliding sealing between the valve core 5 and the valve seat 4. A first spring 11 is provided between the stationary core 14 and the moving core 6, and a second spring 13 is provided between the valve core 5 and the valve body 3.

[0021] Specifically, during operation, the static core 14 is made of soft magnetic material and can be press-fitted and fixed with the sleeve 12. When the coil assembly 2 is energized, the static core 14 generates magnetic force and attracts the moving core 6 upward. The reset force and the adsorption force of the second spring 13 act together on the moving core 6, so that it overcomes the elastic force of the first spring 11 and moves upward to approach the static core 14, and the valve core 5 is away from the valve port. When the coil assembly 2 is powered off, the static core 14 loses its magnetic force, and under the reset force of the first spring 11, the moving core 6 is driven downward to move downward. The moving core 6 simultaneously presses down the valve core 5 to overcome the second spring 13 to approach the valve port, so as to adjust the opening or close the valve port. The valve core 5 and the moving core 6 are in contact through the sealing block 7.

[0022] The valve seat 4 and the sleeve 12 in this embodiment are made of different materials, wherein the sleeve 12 is made of stainless steel and the valve seat 4 is made of aluminum alloy, or other corrosion-resistant, lightweight materials with low cost. The valve seat 4 and the sleeve 12 need to be fixed, and in order to achieve the fixation of the valve seat 4 and the sleeve 12 of different materials, laser welding is used in this embodiment.

[0023] You can continue to refer to Figure 3 and Figure 4 , Figure 3 for Figure 2 Schematic diagram of the connection between the middle sleeve 12 and the valve seat 4; Figure 4 for Figure 3 An enlarged view of the connection position between the middle sleeve 12 and the valve seat 4.

[0024] The valve seat 4 has a mounting hole 4b, which extends axially. Figure 3 As shown, the valve seat 4 has an inner hole that penetrates in the axial direction, the upper part of the inner hole is a mounting hole 4b, and the sleeve 12 is inserted in the mounting hole 4b. The hole wall of the mounting hole 4b is provided with a step surface 41, and the lower end surface of the sleeve 12 abuts against the step surface 41 in the axial direction.

[0025] It is worth noting that in this embodiment, an annular groove 4a is provided at the position where the upper end surface of the valve seat 4 and the hole wall of the mounting hole 4b meet, that is, the upper end surface of the valve seat 4 and the hole wall of the mounting hole 4b are connected by a slope surface, and the axial cross section of the slope surface can be Figure 3The oblique line shown as being inclined relative to the axial direction may also be an arc line, etc. At this time, after the sleeve 12 is inserted into the valve seat 4, the annular groove 4a and the outer wall of the sleeve 12 enclose an annular accommodating cavity, which can be used as a location for storing solder. When the valve seat 4 and the sleeve 12 are welded by laser welding, the solder melted by the welding wire 02 can be located in the annular groove 4a to weld and fix the sleeve 12 and the valve seat 4.

[0026] The following describes a method for manufacturing the solenoid valve 01 by laser welding provided in this embodiment. The manufacturing method specifically includes the following steps:

[0027] Step A, assembling the valve seat 4 and the sleeve; the assembly method of the valve seat 4 and the sleeve is not limited, and can be interference fit or clamped and positioned by tooling, that is, the valve seat 4 and the sleeve can be in a non-fixed position relationship before welding;

[0028] Step B: Use laser welding equipment to convey welding wire 02 to the position of annular groove 4a. Welding wire 02 may be located inside annular groove 4a, or above or obliquely above annular groove 4a, i.e., close to annular groove 4a. In this way, a laser beam may be emitted to the position of annular groove 4a. The laser beam heats welding wire 02 to melt welding wire 02, and the molten solder falls into annular groove 4a. The conveying welding wire 02 and the laser beam run along the circumference of annular groove 4a. After running one circle, welding is completed.

[0029] Step C: Assemble other components of the solenoid valve 01 with the laser-welded components to form the solenoid valve 01.

[0030] In step C, the other components of the solenoid valve 01, that is, the components except the sleeve and the valve seat 4, are fixed together after laser welding. Specifically, the static core 14, the dynamic core 6, the first spring 11, the sealing block 7, the sleeve 12, and the valve seat 4 can be assembled; then the sealing ring 9 and the piston are assembled together and installed in the valve seat 4, and then the return spring is installed, and then the valve body 3 and the valve seat 4 are connected, and finally the coil assembly 2 is assembled to the outer periphery of the sleeve 12 and fixed by the screw assembly 1. It can be seen that the assembly order of other components in this step is not limited to this, as long as they do not interfere with each other, the assembly order can be adjusted. For example, the assembly of the valve body 3 and the valve seat 4 needs to be performed after the piston is installed in the valve seat 4.

[0031] In this embodiment, an annular groove 4a is provided on the valve seat 4, which is conducive to the welding wire 02 being melted and filled in the annular groove 4a under the action of the laser beam. The solder after the welding wire 02 is melted can better contact the sleeve 12 and the valve seat 4, so that the valve seat 4 and the sleeve 12 of different materials can be reliably welded and fixed together. In addition, the sleeve 12 and the valve seat 4 can be interference fit, that is, pre-pressed and positioned, so that during the laser welding process, the positions of the sleeve 12 and the valve seat 4 are relatively stable, which is conducive to stable welding and uniform welding.

[0032] Can continue to combine Figures 5 to 7 understand, Figure 5 It is a schematic diagram of another way of assembling the valve seat 4 and the lower end of the sleeve 12 in the embodiment of the present application; Figure 6 for Figure 5 Enlarged view of the B area; Figure 7 for Figure 6 An enlarged view of the position of the annular gap between the middle valve seat 4 and the sleeve 12.

[0033] In this embodiment, the hole wall of the mounting hole 4b of the valve seat 4 for mounting the sleeve 12 includes a first hole wall section 421 and a second hole wall section 422 distributed along the axial direction. Figure 7 As shown, the first hole wall section 421 and the second hole wall section 422 can be connected by a bevel transition, the second hole wall section 422 is located below the first hole wall section 421, and the second hole wall section 422 is connected to the step surface 41. Figure 6 The diameter of the first hole wall section 421 is D1, the diameter of the second hole wall section 422 is D2, the outer diameter of the sleeve 12 is D3, the diameter D1 is larger than the diameter D2, the outer diameter D3 is larger than the diameter D2 and smaller than the diameter D1, when the sleeve 12 is inserted into the mounting hole 4b of the valve seat 4, it is specifically interference fit with the second hole wall section 422, the interference amount is m, the sleeve 12 and the first hole wall section 421 will have a certain distance in the radial direction, forming an annular gap 01a, and the width of the annular gap 01a along the radial direction is d.

[0034] Thus, during laser welding, the welding wire 02 is melted and located in the annular groove 4a, and can flow into the annular seam 01a through the annular groove 4a to increase the welding area of ​​the valve seat 4 and the sleeve 12. The inclined setting of the annular groove 4a further facilitates the flow of the molten solder into the annular seam 01a. After laser welding, the second hole wall section 422 of the valve seat 4 and the sleeve 12 are interference fit, the first hole wall section 421 and the sleeve 12 are welded and connected, and the outer wall of the sleeve 12 and the valve seat 4 are jointly connected by interference fit and laser welding, and the assembly and fixation are more reliable.

[0035] Specifically, the width d of the annular gap 01a between the first hole wall section 421 of the valve seat 4 and the sleeve 12 can be set to 0.1 mm to 0.3 mm. The characteristics of the laser welding process are that the laser heating area is small and concentrated, the welding time at each position is short, such as only a few seconds, and the cooling speed of the liquid solder is also fast. At this time, in order to ensure that the solder can flow into the annular gap 01a as soon as possible before cooling, the width d of the annular gap 01a can be set to be relatively large, such as within the above-mentioned range of 0.1 mm to 0.3 mm.

[0036] In addition, in this embodiment, the wall thickness of the sleeve 12 is defined as t (shown in Figure 6 ),like Figure 7 As shown, the height of the first hole wall section 421 in the axial direction is Ha, and the height of the second hole wall section 422 in the axial direction is Hb. The height Ha of the first hole wall section 421 can satisfy: Ha = (1 ~ 3) t. It can be seen that the height Ha of the first hole wall section 421 is related to the contact area of ​​the sleeve 12 and the valve seat 4 for welding. It is set to (1 ~ 3) t, which is compatible with the wall thickness and can achieve a better welding effect. In addition, the wall thickness t of the sleeve 12 is also related to the ability to withstand interference fit. The height Hb of the second hole wall section 422 is related to the length of the interference fit section, and accordingly, the height of the annular gap 01a in the axial direction will also be limited. Here, it is set to Ha = (1 ~ 3) t, and the height is relatively short. Under the premise of ensuring welding reliability, it is conducive to ensuring the reliability of interference fit.

[0037] Specifically, when the laser welding operation is performed in step SB, the process parameters of the laser welding can be set as follows:

[0038] Any position of the annular groove 4a in the circumferential direction is selected as the initial position, and the welding wire 02 is fed to the position and the laser beam is emitted, wherein the laser beam can be incident at an angle of 10° to 45° with the vertical plane, that is, the incident angle γ is 10° to 45°, the defocus amount is .5mm to .30mm, and the spot is larger than the radial size of the welding wire 02. The laser power can be set to 1500W to 4000W, and the welding speed can be 4mm to 10mm / s, which is the speed at which the laser beam runs along the circumferential direction of the annular groove 4a. In addition, the wire feeding angle θ of the welding wire 02 can be 30° to 60°, which is the angle between the welding wire 02 and the vertical direction. In order to ensure that the fed welding wire 02 can fall into the annular groove 4a better after melting, the slope angle α of the annular groove 4a can be 45° to 60°, which is the angle between the slope surface and the vertical direction. The selection of the above process parameters is conducive to the feeding of the welding wire 02 and guarantees the welding effect. Of course, the above laser welding process parameters can also be adjusted according to actual conditions.

[0039] Before laser welding, the sleeve 12 and the valve seat 4 can also be cleaned with an organic solvent. Specifically, the sleeve 12 and the valve seat 4 can be cleaned before assembly, or they can be cleaned at the same time after assembly. The organic solvent is, for example, ethanol, acetone, CCl4, etc., and can be specifically cleaned by ultrasonic cleaning to remove oil impurities. After cleaning, the sleeve 12 and the valve seat 4 are immersed in a 10% NaOH and 15% HNO3 solution to remove the oxide film, and then cleaned with anhydrous ethanol and dried, and then laser welding is performed.

[0040] In this embodiment, the sleeve 12 and the valve seat 4 of the solenoid valve 01 are made of different materials. The material of the valve seat 4 is, for example, aluminum alloy, a material with low cost and light weight. In this way, the cost and weight of the assembled solenoid valve 01 are reduced. In order to achieve the connection and fixation of such components of different materials, an annular groove 4a is also provided for laser welding, so that the welding is more reliable. Moreover, laser welding has the advantages of fast heating speed, high efficiency, concentrated energy, minimal heat impact, small deformation of parts, clean joints, and easy automation.

[0041] Specific examples are used herein to illustrate the principles and implementation methods of the present application, and the description of the above embodiments is only used to help understand the method and core ideas of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

Claims

1. A method for manufacturing a solenoid valve, characterized in that: The solenoid valve comprises a sleeve, a valve seat, a static core and a dynamic core, wherein the static core and the dynamic core are arranged opposite to each other in the axial direction, at least a portion of the static core and at least a portion of the dynamic core are located in the sleeve, an annular groove is provided on the upper end surface of the valve seat, and the annular groove and the sleeve are combined to form a receiving cavity for receiving solder, the sleeve and the valve seat are made of different materials, and the method comprises the following steps: inserting the sleeve into the valve seat; Delivering a welding wire to the position of the annular groove, and emitting a laser beam to the welding wire at the position of the annular groove to perform laser welding; The welded sleeve and the valve seat are assembled with other components of the solenoid valve to form the solenoid valve.

2. The method for manufacturing a solenoid valve according to claim 1, characterized in that: The slope angle of the annular groove is 45° to 60°.

3. The method for manufacturing a solenoid valve according to claim 1, characterized in that: The wire feeding angle of the welding wire is 30° to 60°.

4. The method for manufacturing a solenoid valve according to claim 1, characterized in that: The incident angle of the laser beam is 10° to 45°.

5. The method for manufacturing a solenoid valve according to any one of claims 1 to 4, characterized in that: A first hole wall section and a second hole wall section are formed on the inner wall of the valve seat, and the sleeve is interference fit with the second hole wall section. The sleeve and the first hole wall section are spaced radially to form an annular gap, and the annular gap is communicated with the annular groove.

6. The method for manufacturing a solenoid valve according to claim 5, characterized in that: The width of the annular gap in the radial direction is 0.1 mm to 0.3 mm.

7. The method for preparing an electronic expansion valve according to claim 5, characterized in that: The wall thickness of the sleeve is t, and the height Ha of the first hole wall section along the axial direction satisfies: Ha=(1-3)t.

8. The method for manufacturing a solenoid valve according to any one of claims 1 to 4, characterized in that: The material of the valve seat is aluminum alloy, and the material of the sleeve is stainless steel.

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