Manufacturing method of solenoid valve

Abstract

To provide an electromagnetic valve having a fixed structure of a case, an attraction element, and a holder suitable for reducing costs.SOLUTION: An electromagnetic valve 1 includes: a main valve element 40 for opening / closing a main valve port 15 in a valve body 10; a connection body 20 for integrally fixing a case 32 in which a plunger 33 is arranged inside and an electromagnetic coil 34 is mounted outside, a holder 21 connected to the valve body 10, and an attraction element 25 for attracting the plunger 33; and a pilot valve element 36 connected to the plunger 33 through a valve shaft 35 for opening / closing a pilot valve port 45 in the main valve element 40. In the connection body 20, the connection part of the holder 21 and the attraction element 25, and the connection part of the attraction element 25 and the case 32 are both brazed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a solenoid valve. of Regarding the manufacturing method. [Background technology]

[0002] There are two types of solenoid valves: a normally closed type that opens only when current is applied, and a normally open type that closes only when current is applied. There are also direct acting types, in which a valve element is directly opened and closed by a solenoid coil, and pilot types, in which a pilot valve is driven to open and close by a solenoid coil, and the main valve opens and closes in response to the opening and closing of this pilot valve. These types of solenoid valves are used depending on the application. The following patent documents disclose solenoid valves: [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-7572 [Patent Document 2] Japanese Patent Publication No. 2023-2057 Summary of the Invention [Problem to be solved by the invention]

[0004] The solenoid valve described in Patent Document 1 has a threaded portion integrally formed on the attractor so that the attractor can be screwed to the valve body. Because the attractor is machined from a soft magnetic metal workpiece, a large amount of cutting is required, which can increase material and processing costs. Furthermore, because the attractor is exposed to the atmosphere outside the case, the attractor must be corrosion-resistant, which makes it difficult to reduce costs.

[0005] The solenoid valve described in Patent Document 2 is manufactured by processing the holder, which has a threaded portion that screws into the valve body, and the attractor as separate parts, and then integrating the holder and attractor after processing, thereby reducing the amount of machining required on the workpiece. Also, by welding a case to the holder and placing the attractor inside the case, it is possible to manufacture the attractor using a material with low corrosion resistance.

[0006] However, because the case is welded to the holder, the shape of the holder is complex so that the torch (coupler part) of the welding machine does not get in the way during welding. For this reason, further improvements were needed to reduce the number of processing steps and material costs when cutting out the screw members.

[0007] The object of the present invention is to provide a solenoid valve and a method for manufacturing the same that can improve workability during solenoid valve manufacturing by using a fixing structure for a case, attractor, and holder that can solve the above-mentioned problems and contribute to reducing the cost of solenoid valves. [Means for solving the problem]

[0008] In order to achieve the above object, the solenoid valve of the present invention is a solenoid valve having a valve body with a valve port, a case in which a plunger is arranged inside and an electromagnetic coil is attached to the outside, a connecting body in which a holder connected to the valve body and an attractor that attracts the plunger are fixed together, and a valve body connected to the plunger via a valve stem and that opens and closes the valve port, and the connecting body has solder at the connecting part between the holder and the attractor, and at the connecting part between the attractor and the case.

[0009] Alternatively, in order to achieve the above object, the solenoid valve of the present invention is a solenoid valve having a valve body, a main valve element that opens and closes a main valve port in the valve body, a case in which a plunger is arranged inside and an electromagnetic coil is attached to the outside, a holder connected to the valve body, and a connecting body to which an attractor that attracts the plunger is fixed as a single unit, and a pilot valve element that is connected to the plunger via a valve stem and opens and closes a pilot valve port in the main valve element, and the connecting body has solder at the connecting portion between the holder and the attractor, and at the connecting portion between the attractor and the case.

[0010] In order to achieve the above object, the method for manufacturing an electromagnetic valve of the present invention is a method for manufacturing an electromagnetic valve having a valve body with a valve port, a case in which a plunger is placed inside and an electromagnetic coil is attached to the outside, a connecting body in which a holder connected to the valve body and an attractor that attracts the plunger are fixed together, and a valve body connected to the plunger via a valve stem and that opens and closes the valve port, and includes a brazing process in which the connecting body is manufactured by simultaneously brazing the holder and attractor and brazing the attractor and case.

[0011] Alternatively, in order to achieve the above object, the method for manufacturing a solenoid valve of the present invention is a method for manufacturing a solenoid valve having a valve body, a main valve element that opens and closes a main valve port in the valve body, a case in which a plunger is arranged inside and an electromagnetic coil is attached to the outside, a holder connected to the valve body, a connecting body to which an attractor that attracts the plunger is fixed as a single unit, and a pilot valve element that is connected to the plunger via a valve stem and opens and closes a pilot valve port in the main valve element, and includes a brazing process in which the connecting body is manufactured by simultaneously brazing the holder and attractor and brazing the attractor and the case. [Effects of the Invention]

[0012] By using the fixing structure of the case, the attracting element, and the holder portion according to the present invention, it is possible to provide a solenoid valve that can reduce the number of processing steps and material costs during the manufacture of the solenoid valve and improve workability.

[0013] Other objects, features, and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments of the present invention, which is given with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view of a solenoid valve according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of a connector of the solenoid valve of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] A pilot type solenoid valve according to one embodiment of the present invention will be described below with reference to FIGS.

[0016] Figure 1 is a cross-sectional view of a solenoid valve according to one embodiment of the present invention in an open state. Figure 2 is an explanatory diagram of a connector, and is a cross-sectional view that matches Figure 1. In the following description, the terms "up, down, left, right" indicate the relative positional relationships of the components shown in each figure.

[0017] 1, the solenoid valve 1 according to this embodiment has a valve body 10, a connecting body 20, a plunger 33, a solenoid coil 34, a valve stem 35, a pilot valve element 36, and a main valve element 40. Here, the connecting body 20 is a sub-assembly in which an attractor 25, a holder 21 having a threaded portion, and a case 32 are fixed together. The solenoid coil 34 has a coil 34a and a housing 34b, and is attached to the outer periphery of the case 32.

[0018] The valve body 10 has a substantially cylindrical shape. The valve body 10 has an inlet 11, an outlet 12, a main valve chamber 14, a main valve port 15, and a main valve seat 16. The valve body 10 is made of, for example, an aluminum alloy. A thread 10a is formed on the outer periphery of the valve body 10. The solenoid valve 1 of this embodiment is used by attaching it to a housing (flow path block) (not shown) using the thread 10a. When the valve body 10 is inserted into a valve mounting hole in the housing, the outlet 12 on the bottom surface of the valve body 10 communicates with an outlet passage opening at the bottom surface of the valve mounting hole in the housing, allowing the refrigerant in the main valve chamber 14 to flow out through the outlet passage.

[0019] Meanwhile, the valve body 10 has a plurality of openings (in this embodiment, one on each of the front, rear, left and right, for a total of four) on its circumferential surface that can be used as flow paths for the refrigerant flowing into the valve chamber 14, and these openings serve as the inflow ports 11. When the valve body 10 is inserted into the valve mounting hole in the housing, the four openings (inflow ports 11) of the valve body 10 communicate with the inflow passages on the housing side. This allows the refrigerant to flow into the main valve chamber 14 through these openings.

[0020] The valve body 13 has two grooves formed on its outer circumferential surface, and seals (O-rings) 33, 34 are fitted in these grooves to seal the inflow passage side and outflow passage side from the outside.

[0021] The holder 21 is coupled to the mounting portion 17 of the valve body 10. A male thread is formed on the outer peripheral surface of the holder 21, and a female thread is formed on the inner peripheral surface of the mounting portion 17, so that the holder 21 is screwed (threaded) to the mounting portion 17 of the valve body 10. A coupling hole 24 is formed in the inner peripheral surface of the holder 21. The material of the holder 21 is preferably a material that has relatively good corrosion resistance and machinability, such as stainless steel. An O-ring 22 is also placed at the bottom of the mounting portion 17 to seal against refrigerant leakage.

[0022] The suction element 25 has a cylindrical shape. The lower end 25a of the suction element 25 projects outward like a flange, and the outer diameter of the lower end 25a is larger than the outer diameter of the upper end 25b. The lower end 25a is disposed inside the coupling hole 24 of the holder 21 and fixed thereto. Specifically, the lower end 25a is brazed to the coupling hole 24. The outer diameter of the upper end 25b is the same as or slightly smaller than (substantially the same as) the inner diameter of the case 32.

[0023] The attractor 25 in this embodiment is made of free-cutting steel having soft magnetism. The attractor 25 may be made of magnetic stainless steel, but a material with high magnetic permeability and low coercive force is preferred.

[0024] The case 32 is made of non-magnetic stainless steel. The case 32 has a cylindrical shape, is open at the bottom, and is closed at the top by a plug-shaped member 48. The inner diameter of the case 32 is the same (or substantially the same) as the outer diameter of the upper end 25b of the aspirator 25. The plug-shaped member 48 is hermetically fixed to the case 32 by welding. The case 32 is inserted around the outer periphery of the upper end 25b of the aspirator 25 and brazed to the aspirator 25 while being placed on the upper surface (case receiving surface 26) of the lower end 25a. The holder 21 and the aspirator 25 are both fixed by brazing, and the aspirator 25 and the case 32 are both fixed by brazing. The fixing structure of the connector 20 will be described later.

[0025] The stopper-shaped member 48 is made of a magnetic material and includes a cylindrical head 48a with a large outer diameter that closes the top opening of the case 32, and a cylindrical leg 48b with a smaller outer diameter that extends vertically downward from the bottom surface of the head 48a. A female screw 50 is formed in the center of the head 48a from the top surface of the head 48a. The female screw 50 is threadedly engaged with a bolt 51 that secures the housing 34b of the electromagnetic coil 34 (described below). The stopper-shaped member 48 also functions as a stopper that stops the plunger 33 from moving upward when the valve is opened. In this embodiment, a resin or metal ring member 49 is interposed between the stopper-shaped member 48 and the plunger 33 to prevent them from coming into contact and becoming stuck.

[0026] The plunger 33 has a cylindrical shape. The outer diameter of the plunger 33 is slightly smaller than the inner diameter of the case 32. The plunger 33 is disposed inside the case 32 so as to be movable up and down. A plunger spring 38 is disposed between the plunger 33 and the attractor 25. The plunger spring 38 is a compression coil spring. The plunger spring 38 pushes the plunger 33 upward.

[0027] The electromagnetic coil 34 is constructed by surrounding a bobbin around which a coil 34a is wound with a housing 34b made of a magnetic material. The electromagnetic coil 34 is disposed outside the case 32, and the upper plate portion of the housing 34b is fixed to the stopper-shaped member 48 via bolts 51. The electromagnetic coil 34 magnetizes the attractor 25, plunger 33, stopper-shaped member 48, and housing 34b. A wave washer 44 serving as an elastic member is compressed in the gap between the bottom of the electromagnetic coil 34 and the valve body side (more precisely, in the gap between the lower plate portion of the housing 34b and the case receiving surface 26 of the attractor 25).

[0028] When the bolts 51 are tightened to fix the top plate of the housing 34b to the plug-shaped member 48, the wave washer 44 is compressed and elastically deformed, thereby being in pressure contact (pressed into contact) with both the bottom plate of the housing 34b and the case receiving surface 26 of the bottom end 25a of the attractor 25. This absorbs any variations (tolerances) in the dimensions of the housing 34b or in the vertical fixing position of the electromagnetic coil 34 by the bolts 51, preventing gaps from occurring and allowing the bottom plate of the housing 34b, the wave washer 55, and the bottom end 25a to be tightly attached to each other, forming a good magnetic path. A spring washer may be used instead of the wave washer 55.

[0029] The valve shaft 35 is shaft- or rod-shaped. The upper end of the valve shaft 35 is fixed to the lower end of the plunger 33. The valve shaft 35 is arranged to pass through the suction element 25. The valve shaft 35 is supported by the suction element 25 so that it can move up and down. The valve shaft 35 has a fluid passage 35a, which connects the inner space and the outer space of the plunger 33. The pilot valve element 36 is fixed to the lower end of the valve shaft 35. The pilot valve element 36 is a disc-shaped packing made of synthetic resin.

[0030] The main valve element 40 is disposed inside the main valve chamber 14 so as to be movable in the vertical direction, and separates the main valve chamber 14 from the pilot valve chamber 37. The main valve element 40 has a pilot valve port 45 that penetrates in the vertical direction. The pilot valve port 45 connects the main valve port 15 and the pilot valve chamber 37. The upper end of the pilot valve port 45 is open on the top surface of the main valve element 40, and a pilot valve seat 46 that surrounds the pilot valve port 45 is formed.

[0031] The main valve element 40 has a pressure equalizing passage 42a that connects the main valve chamber 14 and the pilot valve chamber 37. A groove is formed on the outer peripheral surface of the upper side of the main valve element 40, and a piston ring 42 is accommodated in the groove. A disc-shaped packing 43 is attached to the underside of the main valve element 40. The packing 43 is made of, for example, a synthetic resin. A valve-opening spring 39 is disposed between the main valve element 40 and the valve body 10. The valve-opening spring 39 is a compression coil spring that presses the main valve element 40 upward.

[0032] In the solenoid valve 1, the main valve chamber 14, the pilot valve chamber 37, and the inner space of the case 32 are spaces into which a refrigerant is introduced, and are sealed from the atmosphere outside the case 32.

[0033] Next, an example of the operation of the solenoid valve 1 will be described.

[0034] In the solenoid valve 1 shown in Figure 1, the solenoid coil 34 is in a non-energized state. In this state, the pilot valve element 36 is separated from the pilot valve seat 46, and the pilot valve port 45 is open. The refrigerant pressure in the main valve chamber 14 is greater than the refrigerant pressure in the pilot valve chamber 37, and the main valve element 40 is pushed upward by the pressure difference and separated from the main valve seat 16, opening the main valve port 15. The solenoid valve 1 is in an open state.

[0035] When the compressor (not shown) of the refrigeration cycle is stopped, the pressure difference between the refrigerant pressure in the main valve chamber 14 and the refrigerant pressure in the pilot valve chamber 37 disappears or becomes small, so the main valve body 40 is pushed upward by the valve-opening spring 39 and moves away from the main valve seat 16, thereby entering an open valve state.

[0036] When the electromagnetic coil 34 is energized, the attractor 25 and plunger 33 are magnetized, and the plunger 33 approaches the attractor 25 against the elastic force of the plunger spring 38. When the pilot valve element 36 moves together with the plunger 33 and closes the pilot valve port 45, refrigerant flows into the pilot valve chamber 37 from the pressure equalizing passage 42a (more precisely, from the gap between the inner circumferential surface of the main valve chamber 14 and the outer circumferential surface of the main valve element 40 and the pressure equalizing passage 42a), and the refrigerant pressure in the pilot valve chamber 37 becomes greater than the refrigerant pressure in the main valve chamber 14. This pressure difference presses the main valve element 40 toward the main valve port 15. The main valve element 40 then closes the main valve port 15, and the solenoid valve 1 enters a closed state.

[0037] When the electromagnetic coil 34 is de-energized again, the magnetization between the attractor 25 and plunger 33 is released, and the plunger 33 is pushed by the plunger spring 38 and moves away from the attractor 25. The pilot valve element 36 moves together with the plunger 33, and the pilot valve port 45 opens. Refrigerant flows from the pilot valve chamber 37 through the pilot valve port 45 to the main valve port 15, and the refrigerant pressure in the main valve chamber 14 becomes greater than the refrigerant pressure in the pilot valve chamber 37. Therefore, the main valve element 40 moves upward (in the valve opening direction), and the solenoid valve 1 opens.

[0038] The connector 20, which is a characteristic feature of the present invention, will now be described.

[0039] FIG. 2 is an explanatory diagram of the connecting body 20. The connecting body 20 has two connection points both connected by brazing. In the brazing process, the assembled state shown in FIG. 2 is introduced into a brazing furnace. FIG. 2 shows the holder 21, the aspirator 25, and the case 32 placed in that order. At this time, brazing material 53a is placed in the gap between the holder 21 and the aspirator 25. Brazing material 53b is placed between the aspirator 25 and the case 32. The case 32 is also placed so that it is inserted into the outer periphery of the aspirator 25. By brazing in this manner, the holder 21, the aspirator 25, and the case 32 can be fixed together in a single brazing process. That is, the brazing process for manufacturing the connecting body 20 simultaneously brazes the holder to the aspirator and brazes the aspirator to the case.

[0040] The brazing filler metals 53a and 53b are ring-shaped brazing filler metals (so-called ring brazing filler metals). The holder 21 supports the lower end 25a of the suction element 25 by the inner flange portion 24a of the coupling hole 24, and the suction element 25 supports the case 32 by the lower end 25a.

[0041] In the brazing process of this embodiment, the brazing material 53a arranged in the gap between the holder 21 and the attractor 25 and the brazing material 53b arranged between the attractor 25 and the case 32 are positioned relatively close to each other. The brazing materials 53a and 53b are made of the same material, and both are in contact with the attractor 25. Therefore, even if there is some deviation in the temperature distribution in the brazing furnace, the brazing materials 53a and 53b will have the same temperature, and therefore brazing defects are unlikely to occur in the brazing process.

[0042] A tapered portion 21b is formed on the upper end side of coupling hole 24 of holder 21 to widen the gap. Brazing filler metal 53a is placed in a recess formed between tapered portion 21b and aspirator 25. Tapered portion 21b makes it easy to place brazing filler metal 53a and also makes it difficult for molten brazing filler metal 53a to flow out, making it easier for it to penetrate between holder 21 and aspirator 25. After brazing, the connection body has solidified brazing filler at the connection portion between holder 21 and aspirator 25 and the connection portion between aspirator 25 and case 32, ensuring sufficient connection strength at the connection portions.

[0043] The suction element 25 has a recess 25c on its outer periphery at a height that continues to the case receiving surface 26, which is the upper surface of the lower end 25a, and this facilitates the placement of the brazing material 53b and the penetration of the molten brazing material 53b in the brazing furnace between the suction element 25 and the case 32. The molten brazing material (53b) penetrates into the gap between the outer periphery of the suction element 25 and the case 32 and solidifies, ensuring sufficient connection strength at the connection portion.

[0044] Since the brazing filler metal 53b is substantially disposed on the case receiving surface 26 of the lower end portion 25a, there is no need to worry about the brazing filler metal 53b becoming misaligned before melting. Even if part of the molten brazing filler metal (53b) overflows onto the outside of the case 32, it simply spreads onto the case receiving surface 26 of the lower end portion 25a. Therefore, the brazing filler metal does not adhere to the outer periphery of the case 32 and does not interfere with the attachment of the electromagnetic coil 34. Note that the recess 25c is not an essential component, and the brazing filler metal 53b may be disposed so as to be sandwiched between the lower end portion 25a and the lower end of the case 32.

[0045] According to the present invention, it is possible to reduce the amount of machining and the number of processing steps for holder 21 and attractor 25, and it is also possible to manufacture connected body 20 in which case, attractor, and holder are fixed together in a single brazing process, which contributes to improving workability during the manufacture of solenoid valves and reducing the cost of solenoid valves. Also, since there are no welds in the area where electromagnetic coil 34 is placed, electromagnetic coil 34 can be installed smoothly.

[0046] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. A person skilled in the art may add, delete, or modify components as appropriate to the above embodiment, and such additions, deletions, or design changes are also included within the scope of the present invention, as long as they do not deviate from the spirit of the present invention. For example, a locking structure using a clip or pin may be adopted instead of the bolt 51 in the above embodiment.

[0047] In the above-described embodiment, the pilot valve 36 is provided as a separate body from the valve stem 35, and the main valve packing 43 is provided on the underside of the main valve body 40. However, the present invention is not limited to this, and a configuration in which the pilot valve 36 and / or the packing 43 are substituted with other configurations may be adopted as long as the pilot valve seat 46 and / or the main valve seat 16 can be closed satisfactorily.

[0048] Furthermore, although the solenoid valves according to the above-described embodiments are normally open pilot-type solenoid valves, the present invention is not limited to such pilot-type solenoid valves. The connecting body 20, which is a characteristic feature of the present invention, can also be applied to direct-acting solenoid valves. For example, direct-acting solenoid valves do not have a main valve body as in the above-described embodiments, but instead open and close the main valve seat using a valve portion attached to a plunger. The connecting body 20, which is attached to the connecting portion and case, can also be used in such direct-acting solenoid valves.

[0049] Furthermore, the solenoid valve according to the present invention can be preferably used in refrigeration cycle devices equipped with a refrigerant circuit, such as air conditioners (air conditioners), freezers, and refrigerators, but is not limited to these and can also be used for a variety of other purposes. [Explanation of symbols]

[0050] 1... solenoid valve, 10... valve body, 11... inlet, 12... outlet, 14... main valve chamber, 15... main valve port, 16... main valve seat, 17... mounting portion, 20... connector, 21... holder, 24... coupling hole, 24a... flange portion, 25... attractor, 25a... lower end portion, 25b... upper end portion, 25c... recess, 26... case receiving surface, 32... case, 33... plunger, 34... electromagnetic coil, 35... valve stem, 35a... fluid passage, 36... pilot valve body, 37... pilot valve chamber, 38... plunger spring, 39... valve opening spring, 40... main valve body, 42... piston ring, 42a... pressure equalizing passage, 43... packing, 44... wave washer, 45... pilot valve port, 46... pilot valve seat, 48... plug-shaped member, 49... ring member, 51... bolt, 53a, 53b... brazing material

Claims

1. a valve body having a valve port; a connecting body that integrally fixes a case in which a plunger is disposed inside and an electromagnetic coil is attached to an outside thereof, a holder that is connected to the valve body, and an attractor that attracts the plunger; a valve body connected to the plunger via a valve stem and configured to open and close the valve port, A method for manufacturing an electromagnetic valve, comprising a brazing step of simultaneously brazing the holder to the attracting element and the attracting element to the case to manufacture the connecting body.

2. A method for manufacturing a solenoid valve having a valve body, a main valve element that opens and closes a main valve port in the valve body, a case in which a plunger is disposed inside and an electromagnetic coil is attached to the outside, a holder connected to the valve body, and a connecting body to which an attractor that attracts the plunger is integrally fixed, and a pilot valve element that is connected to the plunger via a valve stem and opens and closes a pilot valve port in the main valve element, A method for manufacturing an electromagnetic valve, comprising a brazing step of simultaneously brazing the holder to the attracting element and the attracting element to the case to manufacture the connecting body.

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