Solenoid valve

Abstract

To reduce a manufacturing cost of a pilot type solenoid valve.SOLUTION: A solenoid valve 1 comprises: a body 5; a main valve element 22 for opening and closing a main valve by being separably brought into contact with a main valve hole 16 disposed on the body 5; a pilot valve element 84 for opening and closing a pilot valve by being brought into contact with a pilot valve hole 28 disposed on the main valve element 22 separably from a back pressure chamber 36 side; a solenoid 6 having a plunger 48 and a core 44; and a guide member 7, which is a cylindrical body that connects the body 5 and the solenoid 6, having a guide hole 42 through which a partition part 24 of the main valve element 22 is slidably inserted. The guide member 7 has a small diameter part 13 assembled to the core 44 so that an end part of the core 44 is inserted, and a large diameter part 15 so that the partition part 24 is inserted. The back pressure chamber 36 is formed so as to be surrounded by the core 44, the guide member 7 and the main valve element 22. The guide member 7 is formed of a material with a machinability index larger than that of the core 44.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a pilot-operated solenoid valve.

Background Art

[0002] A pilot-operated solenoid valve that autonomously opens and closes a large-diameter main valve by controlling the opening and closing of a small-diameter pilot valve is known (see, for example, Patent Documents 1 and 2). By adopting the pilot operation method, a large valve can be opened and closed with a small solenoid, so that the solenoid valve can be miniaturized and power consumption can be reduced.

[0003] Such a solenoid valve includes a relatively large main valve body constituting the main valve and a relatively small pilot valve body constituting the pilot valve. A back pressure chamber is formed between the solenoid and the main valve body. A pilot passage is provided so as to penetrate the main valve body, and a pilot valve hole is provided at one end of the pilot passage. Then, the pilot valve body approaches and separates from the pilot valve hole from the back pressure chamber side to open and close the pilot valve, whereby the pressure in the back pressure chamber changes, and the main valve body operates in the opening and closing direction of the main valve.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Such a solenoid valve is provided with a guide portion for supporting the main valve body so as to be slidable in the axial direction. This guide portion is often provided integrally with components of the solenoid (such as a core and a sleeve), and is generally made of electromagnetic stainless steel.

[0006] However, electromagnetic stainless steel is generally considered a difficult material to machine because its high viscosity makes it difficult to achieve high cutting accuracy, and the chips tend to stick together, requiring sequential removal. Therefore, when cutting the solenoid components and guide section as a single piece from a single material, not only is the yield poor, but the processing time is also long, resulting in higher manufacturing costs.

[0007] The objective of this invention is to reduce the manufacturing cost of pilot-operated solenoid valves. [Means for solving the problem]

[0008] One aspect of the present invention is a pilot-operated solenoid valve. This solenoid valve comprises a body having an inlet port for introducing fluid, an outlet port for discharging fluid, and a main valve hole provided in a main passage connecting the inlet port and the outlet port; a main valve body having a partition that divides a high-pressure chamber and a back-pressure chamber communicating with the inlet port, with a pilot passage formed through it that connects the outlet port and the back-pressure chamber, and which opens and closes the main valve by moving toward and toward the main valve hole; a pilot valve body that opens and closes the pilot valve by moving toward and toward a pilot valve hole provided at one end of the pilot passage from the back-pressure chamber side; a solenoid having a core fixed to the body, a plunger to which the pilot valve body is fixed and which faces the core in the axial direction; and an electromagnetic coil that forms a magnetic circuit together with the core and the plunger; and a guide member which is a cylindrical body connecting the body and the solenoid and has a guide hole through which the partition is slidably inserted. The guide member has a small-diameter portion that is assembled to the core so as to pass through the end of the core, and a large-diameter portion that passes through the compartment. A back pressure chamber is formed surrounded by the core, the guide member, and the main valve body. The guide member is made of a material with a higher machinability index than the core.

[0009] In this embodiment, the guide member is made of a material with a higher machinability index than the core. That is, since the relatively large guide member is obtained by processing a material with excellent machinability, the processing time can be reduced. On the other hand, even if a difficult-to-machine material is used for the core, it does not require a long time to cut because of its small diameter. Furthermore, since the core and guide member, which have large differences in shape, can be cut from different materials, a high material yield can be maintained. As a result, the manufacturing cost of the pilot-operated solenoid valve can be reduced.

[0010] Another aspect of the present invention is a pilot-operated solenoid valve. This solenoid valve comprises a body having an introduction port for introducing fluid, an outlet port for discharging fluid, and a main valve hole provided in a main passage connecting the introduction port and the outlet port; a main valve body having a partition that divides a high-pressure chamber and a back-pressure chamber communicating with the introduction port, with a pilot passage formed through it that connects the outlet port and the back-pressure chamber, and which opens and closes the main valve by moving toward and toward the main valve hole; a pilot valve body that opens and closes the pilot valve by moving toward and toward a pilot valve hole provided at one end of the pilot passage from the back-pressure chamber side; a solenoid having a core fixed to the body, a sleeve assembled coaxially with the core, a plunger housed in the sleeve and facing the core axially and to which the pilot valve body is fixed; and an electromagnetic coil that forms a magnetic circuit together with the core and the plunger; and a guide member which is a cylindrical body connecting the body and the solenoid and has a guide hole that slides through the partition. The guide member has a small-diameter portion that is assembled to the sleeve so as to pass through the end of the sleeve, and a large-diameter portion that passes through the compartment. A back pressure chamber is formed surrounded by the sleeve, plunger, guide member, and main valve body. The guide member is made of a material with a higher machinability index than the sleeve.

[0011] In this embodiment, the guide member is made of a material with a higher machinability index than the sleeve. That is, since the relatively large guide member is obtained by processing a material with excellent machinability, the processing time can be reduced. On the other hand, even if a relatively difficult-to-machine material is used for the sleeve, it does not require a long time to cut because of its small diameter. Furthermore, since the sleeve and guide member, which have large differences in shape, can be cut from different materials, a high material yield can be maintained. As a result, the manufacturing cost of the pilot-operated solenoid valve can be reduced.

[0012] Yet another aspect of the present invention is a pilot-operated solenoid valve. This solenoid valve comprises a body having an introduction port for introducing fluid, an outlet port for discharging fluid, and a main valve hole provided in a main passage connecting the introduction port and the outlet port; a main valve body having a partition that divides a high-pressure chamber and a back-pressure chamber communicating with the introduction port, with a pilot passage formed through it that connects the outlet port and the back-pressure chamber, and which opens and closes the main valve by moving toward and toward the main valve hole; a pilot valve body that opens and closes the pilot valve by moving toward and toward a pilot valve hole provided at one end of the pilot passage from the back-pressure chamber side; a core fixed to the body; a plunger to which the pilot valve body is fixed and which faces the core in the axial direction; an electromagnetic coil that forms a magnetic circuit together with the core and the plunger; and a guide member which is a cylindrical body connecting the body and the solenoid and has a guide hole that slides through the partition. The guide member has a small-diameter portion that is assembled to the core so as to pass through the end of the core, and a large-diameter portion that passes through the compartment. A back pressure chamber is formed surrounded by the core, the guide member, and the main valve body. The guide member is a resin molded product.

[0013] In this embodiment, the guide member is a resin molded product. That is, a relatively large guide member can be obtained by resin molding using a mold, thus reducing processing time. On the other hand, even if a difficult-to-machine material is used for the core, it does not require a long time to cut because of its small diameter. As a result, the manufacturing cost of the pilot-operated solenoid valve can be reduced. [Effects of the Invention]

[0014] According to the present invention, the manufacturing cost of pilot-operated solenoid valves can be reduced. [Brief explanation of the drawing]

[0015] [Figure 1] This is a cross-sectional view showing the solenoid valve installed on the target object. [Figure 2] This is a cross-sectional view showing the configuration of a solenoid valve. [Figure 3] This is a diagram illustrating the operation of a solenoid valve. [Figure 4] This is a cross-sectional view showing the configuration of a solenoid valve according to Modification Example 1. [Figure 5] This is a cross-sectional view showing the configuration of the solenoid valve according to Modification 2. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described in detail below with reference to the drawings. For convenience, the positional relationships of each structure may be expressed based on the illustrated state in the following description.

[0017] Figure 1 is a cross-sectional view showing the solenoid valve installed on the target object. Solenoid valve 1 is applied to the refrigeration cycle of an automotive air conditioning system (not shown). This refrigeration cycle includes a compressor that compresses the circulating refrigerant, a condenser that condenses the compressed refrigerant, an expansion device that throttles and expands the condensed refrigerant and sends it out in a mist, and an evaporator that evaporates the mist of refrigerant and cools the air inside the vehicle by the latent heat of vaporization. Solenoid valve 1 is attached to the target device that constitutes the refrigeration cycle and controls the flow of the refrigerant.

[0018] The solenoid valve 1 is a pilot-operated solenoid valve and includes a main valve 2 and a pilot valve 4. The solenoid valve 1 is configured by assembling a cylindrical body 5 and a solenoid 6 via a guide member 7. The guide member 7 is a cylindrical body that connects the body 5 and the solenoid 6. The guide member 7 and the body 5 constitute a cylindrical connecting body 9, and the cylindrical connecting body 9 and the solenoid 6 are assembled in the axial direction. The solenoid valve 1 is configured as a normally open valve in which the main valve 2 is in a fully open state when the solenoid 6 is off.

[0019] In the housing 200 of the target device, a passage 210 through which the refrigerant flows and a mounting hole 212 communicating with the passage 210 are provided. The solenoid valve 1 is assembled to the housing 200 such that the cylindrical connecting body 9 is inserted into the mounting hole 212. That is, the solenoid valve 1 has a so-called cartridge structure that can be attached to and detached from the target device by inserting and removing the cylindrical connecting body 9 into and from the mounting hole 212. A main passage 11 that forms a part of the passage 210 is provided in the body 5.

[0020] FIG. 2 is a cross-sectional view showing the configuration of the solenoid valve 1. The body 5 has a stepped cylindrical shape, has an introduction port 10 for introducing the refrigerant on one side surface thereof, and has a discharge port 12 for discharging the refrigerant at the bottom of the body 5. As shown in FIG. 1, the introduction port 10 communicates with the upstream passage 214 in the passage 210, and the discharge port 12 communicates with the downstream passage 216 in the passage 210. A passage that directly connects the introduction port 10 and the discharge port 12 constitutes the main passage 11.

[0021] The inner diameter of the lower part of the body 5 is reduced, and a valve hole 16 is formed therein. A valve seat 18 is formed at the upstream opening end of the valve hole 16, and a discharge port 12 is formed at the downstream opening end of the valve hole 16. The valve hole 16 functions as a "main valve hole", and the valve seat 18 functions as a "main valve seat". A valve chamber 20 is formed upstream of the valve hole 16. The body 5 is obtained by cutting a round bar (material) made of an aluminum alloy, and has a simple shape with a substantially constant outer diameter and a slightly reduced diameter at the lower part, so that the processing cost can be suppressed.

[0022] On the other hand, the guide member 7 has a stepped cylindrical shape with a small-diameter section 13 at the top and a large-diameter section 15 at the bottom. A male screw is provided on the lower outer circumference of the guide member 7, and a female screw is provided on the upper outer circumference of the body 5. By screwing these screws together, the guide member 7 and the body 5 are fastened in the axial direction, forming a cylindrical connector 9.

[0023] The upper end (first open end) of the body 5 is coaxially assembled to the large-diameter portion 15 of the guide member 7, and a valve hole 16 and an outlet port 12 are formed at the lower end (second open end) of the body 5. A valve body 22 is disposed inside the cylindrical connector 9. The valve body 22 functions as the "main valve body".

[0024] The outer diameters of the guide member 7 and the body 5 are approximately equal. An O-ring 62 (seal ring) is provided on the upper outer circumferential surface of the guide member 7, and an O-ring 63 (seal ring) is provided on the lower outer circumferential surface of the body 5. As shown in Figure 1, the O-ring 62 prevents refrigerant leakage and intrusion into the outside atmosphere through the gap between the solenoid valve 1 and the housing 200. The O-ring 63 prevents refrigerant leakage from the upstream passage 214 to the downstream passage 216 when the main valve 2 is closed.

[0025] The valve body 22 has a stepped cylindrical shape, with the upper part slightly enlarged to form a compartment 24. The valve body 22 is obtained by machining an aluminum alloy material and then hard anodizing (surface treatment). A pilot passage 26 is formed so as to penetrate the valve body 22 along its axis. The pilot passage 26 opens toward the valve hole 16. The upper part of the pilot passage 26 is reduced in diameter to form a valve hole 28, and a valve seat 30 is formed at its opening end. The valve hole 28 functions as a "pilot valve hole," and the valve seat 30 functions as a "pilot valve seat."

[0026] A packing 32 is fitted to the lower part of the valve body 22. The packing 32 is made of a ring-shaped elastic body (rubber in this embodiment) and functions as a "sealing member". The packing 32 is fixed to the valve body 22 by crimping the lower end of the valve body 22. The main valve 2 is opened and closed as the valve body 22 is displaced within the valve chamber 20 and the packing 32 attaches to and detaches from the valve seat 18. A spring 33 (functioning as a "biasing member") is interposed between the valve body 22 and the body 5 to bias the valve body 22 upward.

[0027] The compartment 24 divides the space enclosed by the body 5 and the solenoid 6 into a high-pressure chamber 34 and a back-pressure chamber 36. The high-pressure chamber 34 communicates with the inlet port 10, while communicating with the back-pressure chamber 36 via a leak passage 38 provided in the valve body 22. The leak passage 38 functions as an orifice. The back-pressure chamber 36 communicates with the inside of the solenoid 6. The downstream side of the valve hole 16 becomes a low-pressure chamber 40, which communicates with the outlet port 12. The compartment 24 is inserted through a guide hole 42 provided in the large-diameter portion 15 of the guide member 7 (details will be described later). The valve body 22 operates stably in the opening and closing direction of the main valve 2 because the compartment 24 is slidably supported in the guide hole 42.

[0028] On the other hand, the solenoid 6 includes a cylindrical core 44 (fixed core) fixed to the body 5, a bottomed cylindrical sleeve 46 that closes the upper end opening of the core 44, a cylindrical plunger 48 (movable core) housed inside the sleeve 46, a bobbin 50 fitted onto the sleeve 46, an electromagnetic coil 52 wound around the bobbin 50, and a case 53 that encloses the bobbin 50 and the electromagnetic coil 52.

[0029] Case 53 is obtained by injection molding (also called "insert molding" or "mold molding") of a corrosion-resistant resin material. The electromagnetic coil 52 is covered with the molded resin produced by injection molding. Case 53 is made of this molded resin.

[0030] A yoke 55 with a U-shaped cross-section is provided on the outside of the case 53, sandwiching the electromagnetic coil 52 from above and below. The yoke 55 is a magnetic material that forms a magnetic circuit together with the core 44 and plunger 48. Terminals 57 connected to the electromagnetic coil 52 extend from the case 53 (see Figure 1). In this embodiment, the bobbin 50, electromagnetic coil 52, case 53, and yoke 55 are integrated to constitute a coil unit 70.

[0031] The sleeve 46 is made of a non-magnetic metal material (stainless steel in this embodiment). The lower part of the sleeve 46 is fitted onto the upper part of the core 44 and fixed by outer circumference welding. Together with the core 44, the sleeve 46 forms a can that closes the internal pressure chamber. The plunger 48 is a magnetic material made of electromagnetic stainless steel (e.g., SUS304S) and is arranged coaxially with the core 44. A back pressure chamber 54 is formed between the bottom of the sleeve 46 and the plunger 48. The core 44, sleeve 46 and plunger 48 constitute the operating unit 72.

[0032] The core 44 is a magnetic material made of electromagnetic stainless steel (e.g., SUS304S) and is inserted into the electromagnetic coil 52. The upper end of the core 44 faces the plunger 48 in the axial direction, and the lower end protrudes below the yoke 55. A back pressure chamber 36 is formed surrounded by the core 44, the guide member 7, and the valve body 22.

[0033] A spring receptacle 88 is provided at the axial center of the core 44, projecting radially inward. A spring 86 (functioning as a "biasing member") is interposed between the plunger 48 and the spring receptacle 88, biasing the plunger 48 away from the core 44. Complementary tapered surfaces are provided on the opposing surfaces of the core 44 and the plunger 48, ensuring a large stroke for the plunger 48 while obtaining sufficient magnetic attraction force.

[0034] An annular seal housing 76 is formed at the upper end opening of case 53, and an O-ring 78 (seal ring) is fitted into it. Similarly, an annular seal housing 80 is formed at the lower end opening of case 53, and an O-ring 82 (seal ring) is fitted into it. The interposition of O-rings 78 and 82 between the coil unit 70 and the operating unit 72 prevents the intrusion of outside air (moisture) through the gap between them.

[0035] A shaft 83 extends coaxially from the lower end of the plunger 48. The shaft 83 extends inward from the core 44 and passes through the spring seat portion 88, with a pilot valve body 84 provided at its tip. The pilot valve body 84 is a stepped cylindrical shape, and the lower end of the shaft 83 is press-fitted coaxially into its upper half. The pilot valve body 84 is made of stainless steel (SUS), and a seal member 90 is fixed to its lower end. The seal member 90 is made of rubber.

[0036] The pilot valve body 84 is positioned in the back pressure chamber 36. The pilot valve 4 is opened and closed by the attachment and detachment of the sealing member 90 of the pilot valve body 84 to the valve seat 30. The pressure in the back pressure chamber 36 is introduced into the back pressure chamber 54 through the gap between the outer surface of the pilot valve body 84 and the inner surface of the core 44, and the gap between the outer surface of the plunger 48 and the inner surface of the sleeve 46.

[0037] The guide member 7 is obtained by machining an aluminum alloy material and then hard anodizing (surface treatment), and has excellent corrosion resistance. An annular groove 58 is formed on the upper outer circumference of the guide member 7, and an O-ring 62 is fitted into it. The small diameter portion 13 of the guide member 7 passes through the lower part of the core 44. The lower end opening of the small diameter portion 13 is slightly enlarged to form a stepped portion, while the lower end of the core 44 is provided with a flange portion 47 that protrudes radially outward. The flange portion 47 is locked into the stepped portion, ensuring that the relative axial positional relationship between the core 44 and the guide member 7 is as designed. The open end of the small diameter portion 13 is crimped inward (not shown), fixing the guide member 7 to the core 44.

[0038] An annular groove 59 is formed on the lower outer surface of the core 44, and an O-ring 65 (seal ring) is fitted into it. By interposing the O-ring 65 between the lower outer surface of the core 44 and the inner surface of the small diameter portion 13, leakage of refrigerant through the gap between them is prevented.

[0039] An annular groove 100 is provided on the outer circumferential surface of the compartment 24 in the valve body 22, and a piston ring 102 is fitted into it. The piston ring 102 is made of polytetrafluoroethylene (PTFE). The compartment 24 is slidably supported in the guide hole 42 at the position of the piston ring 102.

[0040] In this configuration, the pressure P1 introduced into the inlet port 10 (referred to as "upstream pressure P1") becomes pressure P2 (referred to as "downstream pressure P2") after passing through the main valve 2 in the main passage 11 (see Figure 1). Furthermore, the upstream pressure P1 introduced into the high-pressure chamber 34 becomes an intermediate pressure Pp in the back pressure chamber 36 after passing through the leak passage 38, and then becomes the downstream pressure P2 after passing through the pilot valve 4.

[0041] Next, the operation of the solenoid valve 1 will be explained in detail. Figure 3 is a diagram illustrating the operation of the solenoid valve 1, showing the energized state with the solenoid 6 turned on. Figure 2, which has already been explained, shows the de-energized state with the solenoid 6 turned off.

[0042] As shown in Figure 2, when the solenoid 6 is turned off, no solenoid force acts, so the plunger 48 is biased upward by the spring 86, and the pilot valve 4 opens. At this time, the refrigerant in the back pressure chamber 36 is led downstream through the pilot passage 26, and the intermediate pressure Pp decreases, so the valve body 22 is biased upward by the differential pressure (P1-Pp) between the upstream pressure P1 and the intermediate pressure Pp. As a result, the main valve 2 opens completely. Consequently, the main passage is opened as shown in the figure. That is, the refrigerant introduced from the inlet port 10 is mainly led out from the outlet port 12 through the main passage 11.

[0043] On the other hand, as shown in Figure 3, when the solenoid 6 is turned on, an attractive force (solenoid force) acts between the core 44 and the plunger 48, biasing the plunger 48 downward and closing the pilot valve 4. At this time, refrigerant from the upstream side is introduced into the back pressure chamber 36 via the leak passage 38, so the intermediate pressure Pp becomes the upstream pressure P1. As a result, the valve body 22 is biased downward by the differential pressure (Pp-P2) between the intermediate pressure Pp and the downstream pressure P2. This causes the main valve 2 to close, blocking the main passage 11.

[0044] As described above, in this embodiment, the core 44 and the guide member 7 are separated as separate components, and the material used for the guide member 7 is one that has better machinability than the core 44 (a material that allows for high-precision cutting in a relatively short time). Specifically, the material of the guide member 7 is an aluminum alloy, which has a higher machinability index than the electromagnetic stainless steel used for the core 44.

[0045] Here, "machinability index" is an index that represents the ease or difficulty of cutting a metallic material, and specifically refers to a value that indicates the ease of cutting a material with respect to sulfur free-cutting steel (AISI-B1112) (see, for example, Japanese Patent Publication No. 2005-335091). Materials with a higher machinability index are easier to cut.

[0046] The core 44 is a small cylindrical member capable of housing the pilot valve body 84, and because the difference in shape along the axial direction (change in inner and outer diameter) is small, the amount of material removed is minimal. Therefore, it does not require a long time to process electromagnetic stainless steel, which is generally considered a difficult material to machine. On the other hand, the guide member 7 is a large stepped cylindrical member capable of housing the valve body 22, and because the difference in shape along the axial direction is large, the amount of material removed is substantial. However, because an aluminum alloy with a relatively high machinability index (i.e., a material with excellent machinability) is used, machining accuracy can be maintained even when the cutting speed (tool feed rate) is increased. In other words, according to this embodiment, the total cutting time of the stepped structure consisting of the core 44 and the guide member 7 can be shortened, and machining costs can be reduced.

[0047] If the core 44 and guide member 7 were to be integrally formed using only machining with a single material (a round bar of electromagnetic stainless steel), a large amount of difficult-to-machine material would have to be removed. This would necessitate a slow machining speed (cutting feed rate) and careful machining, resulting in longer machining times. The large difference in shape along the axial direction (change in inner and outer diameter) would generate a large amount of chips, significantly reducing the material yield. In this respect, according to this embodiment, the core 44 and guide member 7, which have a large difference in shape, can be cut from separate materials, thus maintaining a high material yield. The amount of difficult-to-machine material removed can be kept to a minimum. As a result, the manufacturing cost of the solenoid valve 1 can be reduced.

[0048] Although preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these specific embodiments, and various modifications are possible within the scope of the technical concept of the present invention.

[0049] [Differentiation] Figure 4 is a cross-sectional view showing the configuration of the solenoid valve according to Modification 1. The solenoid valve 101 in this modified example differs from the above embodiment in that it does not have a cartridge structure with a cylindrical connector. The solenoid valve 101 is constructed by assembling a solenoid 6 to a large block-shaped (prismatic) body 105.

[0050] The body 105 is made of aluminum alloy and has a mounting hole 112 in the upper center. The solenoid 6 is assembled to the body 105 via a guide member 7. An inlet port 10 is provided on one side of the body 105 and an outlet port 12 is provided on the opposite side.

[0051] A circular boss-shaped valve seat forming portion 114 is provided at the communication point between the inlet port 10 and the outlet port 12 in the body 105. A valve hole 16 is formed inside the valve seat forming portion 114. A valve seat 18 is formed at the open end of the valve seat forming portion 114. A spring 33 is interposed between the valve body 22 and the body 105. The core 44 is made of electromagnetic stainless steel, and the material of the guide member 7 is made of aluminum alloy, as in the above embodiment.

[0052] In this modified example, the core 44 and the guide member 7 are separated as separate components, and the guide member 7 is made of a metal material with a higher machinability index than the core 44. Therefore, the same effects as in the above embodiment can be obtained.

[0053] Figure 5 is a cross-sectional view showing the configuration of the solenoid valve according to Modification Example 2. The solenoid valve 201 differs from the above embodiment in that it is configured as a normally closed valve in which the main valve 2 is closed when the solenoid 206 is off. On the other hand, the solenoid valve 201 is similar to the above embodiment in that the guide member 207 and the body 205 constitute a cylindrical connector 209 and have a so-called cartridge structure that can be attached to and detached from the target device.

[0054] The body 205 and the guide member 207 have substantially the same configuration as the body 5 and guide member 7 of the above embodiment, respectively, but the joining structure for forming the cylindrical connecting body is different. The lower part of the guide member 207 is inserted through the upper part of the body 205, and the two are fixed together by crimping the upper end of the body 205 inward.

[0055] The solenoid 206 includes a sleeve 246 assembled to the body 205 via a guide member 207, a core 244 assembled coaxially with the sleeve 246, a plunger 248 positioned opposite the core 244 within the sleeve 246, a bobbin 50 externally fitted to the sleeve 246 and core 244, an electromagnetic coil 52 wound around the bobbin 50, and a case 53 enclosing the bobbin 50 and the electromagnetic coil 52. The cross-sectional structure of the illustrated solenoid 206 corresponds to a cross-section perpendicular to the longitudinal cross-section of the solenoid 6 shown in Figure 2. The solenoid valve 201 is fixed to the target device by fastening the bottom of the yoke 55 to the housing 200 via a plurality of bolts 220.

[0056] The plunger 248 is positioned between the core 244 and the valve body 22. A pilot valve body 284 is fixed to the center of the lower end of the plunger 248. The pilot valve body 284 is made of a ring-shaped elastic body (rubber in this embodiment) and functions as a "sealing member".

[0057] The sleeve 246 is cylindrical, with its lower part protruding below the yoke 55. A flange portion 247 is provided at the lower end of the sleeve 246, protruding radially outward. The lower end of the sleeve 246 is inserted into the small-diameter portion 13 of the guide member 207, and the flange portion 247 is locked into the stepped portion of the small-diameter portion 13, thereby ensuring that the axial relative positional relationship between the sleeve 246 and the guide member 207 is as designed. The open end of the small-diameter portion 13 is crimped inward, thereby fixing the guide member 207 to the sleeve 246.

[0058] An O-ring 65 (seal ring) is interposed between the lower outer circumferential surface of the sleeve 246 and the inner circumferential surface of the small diameter portion 13, preventing refrigerant leakage through the gap between the sleeve 246 and the guide member 207. A back pressure chamber 36 is formed surrounded by the sleeve 246, plunger 248, guide member 207, and main valve body 22.

[0059] The core 244 has a stepped cylindrical shape, and its lower half fits into the upper end of the sleeve 246, closing the upper end opening of the sleeve 246. A spring 86 is interposed between the plunger 248 and the core 244 to bias the plunger 248 in the closing direction of the pilot valve 4. The back pressure chamber 36 communicates with the back pressure chamber 54 via a communication groove 249 formed on the outer circumferential surface of the plunger 248 and an internal passage of the core 244.

[0060] In this modified example, the sleeve 246 is made of non-magnetic stainless steel, and the guide member 207 is made of an aluminum alloy. That is, the sleeve 246 and the guide member 207 are separated as separate components, and the guide member 207 is made of a metal material with a higher machinability index than the sleeve 246. Therefore, the same effects as in the above embodiment can be obtained.

[0061] [Other variations] In the above embodiment, the solenoid valve 1 is exemplified as a control valve applied to a refrigeration cycle to control the flow of refrigerant. In modified examples, it may be a control valve that controls the flow of fluid in other devices, such as a control valve that controls the flow of hot water in a hot water supply system.

[0062] In the above embodiment, an example was shown in which a guide member 7 is obtained by machining a round bar made of aluminum alloy. In a modified example, the primary molded product of the guide member 7 may be manufactured by forging using a material made of aluminum alloy. Then, the surfaces of the primary molded product that require precision may be finished by machining. That is, the guide member may have machined finished surfaces on at least the inner circumferential surface through which the core is inserted in the small diameter portion and the inner circumferential surface through which the main valve body slides in the large diameter portion.

[0063] In the above embodiment, an example was shown in which an aluminum alloy is used as the material for the guide member 7. However, metal materials with a higher machinability index than electromagnetic stainless steel, such as free-cutting steel or brass, may also be used. It is sufficient as long as the guide member is made of a material with a higher machinability index than the core or sleeve.

[0064] In the above embodiment, an example was shown in which the aluminum alloy guide member 7 is subjected to hard anodizing treatment. However, the corrosion resistance and hardness (wear resistance) of the guide member may be ensured by electroless nickel plating or other surface treatments.

[0065] In the above embodiment, an example was shown in which both the guide member 7 and the valve body 22 are anodized. In a modified example, anodizing may be applied only to the guide member 7. From the viewpoint of preventing galvanic corrosion between the guide member 7 and the core 44, it is preferable to anodize the guide member 7.

[0066] The above embodiments and modifications show examples of obtaining the guide member 7,207 by cutting a metal material. In other modifications, the guide member may be a resin molded product made of a resin material such as polyphenylene sulfide (PPS). Since the guide member does not need to be magnetic, it may be obtained by resin molding using a mold, such as injection molding of resin material. This further reduces the processing time of the guide member and the processing cost. It is also preferable in that it improves the sliding properties of the piston ring 102. If a PPS resin containing polytetrafluoroethylene (PTFE) is used, the sliding properties can be further improved.

[0067] Furthermore, in the above embodiments and modifications, the body 5,205 is made of an aluminum alloy, but it may also be made of a resin material such as PPS. This makes it possible to improve the surface accuracy of the contact portion of the sealing member (rubber) of the valve body 22, and improve the durability of the sealing member.

[0068] In the above embodiments and modifications, the plungers 48 and 248 are made of electromagnetic stainless steel, but they may be made of free-cutting steel or other ferrous materials. Also, the pilot valve body 84 is made of stainless steel, but it may be made of brass or other metallic materials.

[0069] It should be noted that the present invention is not limited to the embodiments and modifications described above, and the components can be modified and implemented without departing from the spirit of the invention. Various inventions may be formed by appropriately combining the multiple components disclosed in the embodiments and modifications described above. In addition, some components may be deleted from all the components shown in the embodiments and modifications described above. [Explanation of Symbols]

[0070] 1 Solenoid valve, 2 Main valve, 4 Pilot valve, 5 Body, 6 Solenoid, 7 Guide member, 9 Cylindrical connector, 10 Inlet port, 11 Main passage, 12 Outlet port, 13 Small diameter section, 15 Large diameter section, 16 Valve bore, 18 Valve seat, 22 Valve body, 22 Main valve body, 24 Compartment section, 26 Pilot passage, 28 Valve bore, 30 Valve seat, 34 High pressure chamber, 36 Back pressure chamber, 38 Leak passage, 40 Low pressure chamber, 42 Guide bore, 44 Core, 46 Sleeve, 48 Plunger, 52 Electromagnetic coil, 55 Yoke, 56 Small diameter section, 70 Coil unit, 72 Actuating unit, 83 Shaft, 84 Pilot valve body, 90 Seal member, 101 Solenoid valve, 102 Piston ring, 105 Body, 200 Housing, 201 Solenoid valve, 205 body, 206 solenoid, 207 guide member, 209 cylindrical connector, 210 passage, 212 mounting hole, 214 upstream passage, 216 downstream passage, 220 bolt, 244 core, 246 sleeve, 248 plunger, 249 communication groove, 284 pilot valve body.

Claims

1. A body having an introduction port for introducing fluid, an outlet port for discharging fluid, and a main valve hole provided in the main passage connecting the introduction port and the outlet port, A main valve body having a partition that separates a high-pressure chamber and a back-pressure chamber communicating with the aforementioned inlet port, a pilot passage formed through which the outlet port and the back-pressure chamber communicate, and moving toward and away from the main valve hole to open and close the main valve, A pilot valve body is provided at one end of the pilot passage, which moves toward and away from the back pressure chamber side to open and close the pilot valve, A solenoid having a core fixed to the body, a plunger to which the pilot valve body is fixed and which faces the core in the axial direction, and an electromagnetic coil that together with the core and the plunger forms a magnetic circuit, A cylindrical body connecting the body and the solenoid, and a guide member having a guide hole through which the partition portion is slidably inserted, Equipped with, The guide member has a small-diameter portion that is assembled to the core so as to pass through the end of the core, and a large-diameter portion that passes through the partitioned portion. The back pressure chamber is formed so as to be surrounded by the core, the guide member and the main valve body. A solenoid valve characterized in that the guide member is made of a material with a higher machinability index than the core.

2. The solenoid valve according to claim 1, characterized in that the guide member is a forged product and has machined finished surfaces on at least the inner circumferential surface through which the core is inserted in the small diameter portion and the inner circumferential surface through which the main valve body slides in the large diameter portion.

3. The core is made of stainless steel, while the guide member is made of an aluminum alloy. The solenoid valve according to claim 1 or 2, characterized in that the guide member is anodized, and a seal ring is interposed between the inner circumferential surface of the guide member and the outer circumferential surface of the core to restrict fluid leakage.

4. The body is cylindrical in shape, having a first open end and a second open end coaxially. The first open end is assembled coaxially to the large diameter portion of the guide member, The main valve hole and the outlet port are formed at the second open end. The introduction port is opened on the side of the body located between the first opening end and the second opening end. The solenoid valve according to claim 1 or 2, characterized in that the cylindrical connecting body comprising the guide member and the body is configured to be insertable into the mounting hole of the target device.

5. A body having an introduction port for introducing fluid, an outlet port for discharging fluid, and a main valve hole provided in the main passage connecting the introduction port and the outlet port, A main valve body having a partition that separates a high-pressure chamber and a back-pressure chamber communicating with the aforementioned inlet port, a pilot passage formed through which the outlet port and the back-pressure chamber communicate, and moving toward and away from the main valve hole to open and close the main valve, A pilot valve body is provided at one end of the pilot passage, which moves toward and away from the back pressure chamber side to open and close the pilot valve, A solenoid comprising: a core fixed to the body; a sleeve assembled coaxially with the core; a plunger housed within the sleeve and axially facing the core, to which the pilot valve body is fixed; and an electromagnetic coil that together with the core and the plunger form a magnetic circuit. A cylindrical body connecting the body and the solenoid, and a guide member having a guide hole through which the partition portion is slidably inserted, Equipped with, The guide member has a small diameter portion that is assembled to the sleeve so as to pass through the end of the sleeve, and a large diameter portion that passes through the partition portion. The back pressure chamber is formed so as to be surrounded by the sleeve, the plunger, the guide member, and the main valve body. A solenoid valve characterized in that the guide member is made of a material with a higher machinability index than the sleeve.

6. A body having an introduction port for introducing fluid, an outlet port for discharging fluid, and a main valve hole provided in the main passage connecting the introduction port and the outlet port, A main valve body having a partition that separates a high-pressure chamber and a back-pressure chamber communicating with the aforementioned inlet port, a pilot passage formed through which the outlet port and the back-pressure chamber communicate, and moving toward and away from the main valve hole to open and close the main valve, A pilot valve body is provided at one end of the pilot passage, which moves toward and away from the back pressure chamber side to open and close the pilot valve, A solenoid having a core fixed to the body, a plunger to which the pilot valve body is fixed and which faces the core in the axial direction, and an electromagnetic coil that together with the core and the plunger forms a magnetic circuit, A cylindrical body connecting the body and the solenoid, and a guide member having a guide hole through which the partition portion is slidably inserted, Equipped with, The guide member has a small-diameter portion that is assembled to the core so as to pass through the end of the core, and a large-diameter portion that passes through the partitioned portion. The back pressure chamber is formed so as to be surrounded by the core, the guide member and the main valve body. A solenoid valve characterized in that the guide member is a resin molded product.

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