Solenoid valve

Abstract

To provide a solenoid valve which enables stable control of a flow rate and a pressure of a fluid.SOLUTION: A poppet type solenoid valve 1 includes: a valve body 51; a valve seat 40a on which the valve body 51 is seated; a solenoid 80 which has a movable iron core 84, a rod 83, and a fixed iron core 82 and exerts driving force on the valve body 51 in a valve closing direction; a spring 90 which biases the valve body 51 in a valve opening direction; and a valve housing 10 defining a valve chamber 4 in which the valve body 51 and the valve seat 40a are disposed. A spring chamber 5 in which a spring 90 is disposed is defined between the valve chamber 4 and the fixed iron core 82. The valve body 51 isolates the valve chamber 4 and the spring chamber 5 when the valve is open.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a solenoid valve for controlling a fluid.

Background Art

[0002] A solenoid valve used for controlling a fluid in various industrial fields includes a valve body that contacts and separates from a valve seat according to the electric power input to the solenoid, and by adjusting the valve opening degree, it is possible to control the flow rate and pressure of the fluid.

[0003] Typical forms of such valves include a spool type in which a spool as the valve body moves parallel to an opening as the valve seat, and a poppet type in which the valve body moves orthogonally to the opening as the valve seat. Among these valves, the poppet type valve is most suitable for controlling the flow rate and pressure.

[0004] For example, the poppet type solenoid valve shown in Patent Document 1 mainly includes a valve housing that defines a valve chamber in which the valve body and the valve seat are arranged, a solenoid for applying a closing force to the valve body in the closing direction, and a spring for biasing the valve body in the opening direction. In the solenoid, when the coil is energized, the movable iron core is attracted to the fixed iron core by magnetic force. When the movable iron core is attracted, the rod fixed to the movable iron core moves accordingly, and the valve body moves toward the valve seat together with the rod, and the valve body seats on the valve seat, and the solenoid valve closes. Also, when the energization of the coil stops, the valve body moves in the opening direction by the biasing force of the spring, and the valve body separates from the valve seat, so the solenoid valve opens.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In a solenoid valve such as that of Patent Document 1 as described above, the spring is externally fitted to the valve body on the solenoid side rather than on the inflow passage and the outflow passage. Therefore, the fixed core and the movable core are not subject to the shape constraints by the spring, and it is easy to form a sufficient magnetic path. In addition, it is difficult to inhibit the flow of the fluid flowing from the inflow passage to the outflow passage. By the way, when the valve is opened, the fluid flows into the space in the solenoid and the outer diameter space of the valve body where the spring is disposed from the valve chamber. If the fluid contains contaminants, the functions of the solenoid and the spring are impaired, and there is a risk of hindering the control of the flow rate and pressure.

[0007] The present invention has been made paying attention to such problems, and an object thereof is to provide a solenoid valve capable of stably controlling the flow rate and pressure of a fluid.

Means for Solving the Problems

[0008] In order to solve the above problems, the solenoid valve of the present invention includes a valve body, a valve seat on which the valve body seats, a solenoid having a movable core, a rod, and a fixed core, and exerting a driving force in the closing direction on the valve body, a spring that biases the valve body in the opening direction, a poppet-type solenoid valve including a valve housing that defines a valve chamber in which the valve body and the valve seat are disposed, a spring chamber in which the spring is disposed is defined between the valve chamber and the fixed core, the valve body isolates the valve chamber and the spring chamber when the valve is opened. According to this, at the time of valve opening, the spring chamber is isolated from the valve chamber by the valve body. Therefore, it is extremely difficult for fluid to flow into the spring chamber at the time of valve opening. As a result, it is difficult for fluid containing contaminants to flow from the valve chamber into the spring chamber at the time of valve opening and for the functions of the solenoid and the spring to be impaired. Thus, the solenoid valve can stably control the flow rate and pressure of the working fluid.

[0009] The valve body may abut against the valve housing at the time of valve opening. According to this, the valve body abutting against the valve housing can more preferably prevent fluid from flowing into the spring chamber. Further, the housing functions as a stopper for holding the position of the valve body at the time of valve opening. Thus, the configuration of the solenoid valve becomes simple. Also, when the energization ends and the valve body moves in the valve opening direction and reaches the fully open state, a fluid flow from the spring chamber toward the valve chamber occurs between the spring chamber and the valve chamber. As a result, contaminants are easily discharged from the spring chamber.

[0010] A passage communicating the valve chamber and the spring chamber may be provided. According to this, in the valve open state, fluid flows in and out of the spring chamber from the valve chamber through the passage. Therefore, at the start of energization, the valve body smoothly moves in the valve closing direction, and at the end of energization, the valve body smoothly moves in the valve opening direction and reaches the fully open state.

[0011] The passage may be constituted by a groove formed in the valve body. According to this, the configuration of the passage becomes simple.

[0012] The spring is a conical coil spring, The rod may be provided with a spring stopper against which the small-diameter end of the spring abuts. According to this, the spring stopper is less likely to receive the resistance of the fluid, and the driving force of the solenoid can be reduced.

[0013] The valve body and the rod may be connected. According to this, when one of the rod and the valve body is slidably guided, the sliding guide of the other can be omitted. That is, the solenoid valve has a simple centering structure.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0015] Modes for carrying out the solenoid valve according to the present invention will be described below based on examples.

Examples

[0016] The solenoid valve according to Example 1 will be described with reference to FIGS. 1 to 4. Hereinafter, the up and down as viewed from the front of FIG. 1 will be described as the up and down of the solenoid valve. Specifically, the upper side of the paper surface where the solenoid is arranged will be described as the upper side of the solenoid valve, and the lower side of the paper surface where the valve housing is arranged will be described as the lower side of the solenoid valve.

[0017] As shown in FIG. 1, the solenoid valve 1 is composed of a valve section 9 and a solenoid 80. The valve section 9 is mainly composed of a valve housing 10, a valve body 51, and a conical coil spring 90. The valve housing 10 is formed of a metal material or a resin material. The valve body 51 and the coil spring 90 are disposed within the valve housing 10. The solenoid 80 is connected to the valve housing 10 and is for applying a driving force to the valve body 51.

[0018] First, the configuration of the valve section 9 will be described. The elements of the valve section 9 are the valve housing 10, the valve 50, and the coil spring 90. The valve housing 10 is formed with a small-diameter cylindrical portion 12, an intermediate cylindrical portion 14 having an inner diameter larger than that of the small-diameter cylindrical portion 12, and a cylindrical portion 15 having an inner diameter slightly smaller than that of the intermediate cylindrical portion 14, in order from the solenoid 80 side, i.e., the upper side.

[0019] An annular step portion 11 that expands in the outer diameter direction is formed at the upper end of the small-diameter cylindrical portion 12. The annular step portion 11 has an annular bottom surface that extends in the inner diameter direction orthogonally to the annular inner peripheral surface that extends in the vertical direction.

[0020] An annular rib 13 that extends toward the inner diameter side is formed at the lower end of the small-diameter cylindrical portion 12. The upper surface of the annular rib 13 is the bottom surface 12a of the annular step portion 11. The inner diameter is constant between the annular step portion 11 and the annular rib 13.

[0021] The small-diameter cylindrical portion 12, together with a center post 82 described later, defines a spring chamber 5 in which the coil spring 90 is disposed.

[0022] Here, the coil spring 90 will be described. The coil spring 90 is conical and expands in diameter from the upper side downward, and has a small-diameter end 91 and a large-diameter end 92. The small-diameter end 91 abuts against a spring stopper 93, and the large-diameter end 92 abuts against the bottom surface 12a in the small-diameter cylindrical portion 12.

[0023] The coil spring 90 is disposed in a compressed state between the bottom surface 12a of the small-diameter cylindrical portion 12 and the spring stopper 93. Thereby, the coil spring 90 biases the rod 83 in the valve opening direction of the valve 50, that is, upward in the axial direction.

[0024] Returning to the description of the valve housing 10, the intermediate cylindrical portion 14 is formed continuously with the annular rib 13 and has a ceiling surface 14a, an inner peripheral surface 14b, and a bottom surface 14c.

[0025] The ceiling surface 14a extends in the outer diameter direction and is formed in an annular shape. A part of the ceiling surface 14a also serves as the inner diameter side end surface of the annular rib 13.

[0026] The inner peripheral surface 14b extends downward substantially orthogonally to the outer diameter edge of the ceiling surface 14a.

[0027] The bottom surface 14c extends in the inner diameter direction substantially orthogonally to the lower edge of the inner peripheral surface 14b and is formed in an annular shape.

[0028] Also, the ceiling surface 14a extends longer in the inner diameter direction than the bottom surface 14c.

[0029] Also, in the peripheral wall of the intermediate cylindrical portion 14, six inflow paths 2 communicating in the radial direction are equally arranged in the circumferential direction.

[0030] Also, a bottomed cylindrical valve body 51 is disposed in the intermediate cylindrical portion 14.

[0031] The outer diameter of the valve body 51 is smaller than the inner diameter of the inner peripheral surface 14b in the intermediate cylindrical portion 14. The outer peripheral surface of the valve body 51 is separated from the inner peripheral surface 14b in the intermediate cylindrical portion 14.

[0032] Here, the valve body 51 will be described. The valve body 51 has a ceiling portion 52 and a cylindrical portion 53.

[0033] The ceiling portion 52 in the valve body 51 is formed in a disc shape, and a through hole penetrating in the axial direction is formed at the center in the radial direction thereof. Further, the outer diameter of the ceiling portion 52 is longer than the inner diameter of the ceiling surface 14a in the intermediate cylindrical portion 14. Thus, the ceiling portion 52 is configured such that its upper end surface 52a can contact the ceiling surface 14a.

[0034] Also, as shown in FIGS. 1 and 2(a), one groove 52b that is open in the outer diameter direction and upward direction and extends in the inner diameter direction is formed in the upper end surface 52a of the ceiling portion 52. The groove 52b communicates the valve chamber 4 in which the valve body 51 is disposed and the spring chamber 5 in the fully open state of the valve 50 described later.

[0035] As shown in FIGS. 1 and 2(b), the cylindrical portion 53 in the valve body 51 extends downward substantially orthogonally to the outer diameter end of the ceiling portion 52. Further, a tapered surface 53a that reduces in diameter downward is formed at the lower end of the cylindrical portion 53.

[0036] Also, the lower end of the rod 83 is press-fitted and fixed into the through hole in the valve body 51. Note that the fixing of the rod 83 to the valve body 51 may be other than press-fitting.

[0037] Returning to the description of the valve housing 10, the lower cylindrical portion 15 is continuous with the intermediate cylindrical portion 14, extends downward substantially orthogonally to the bottom surface 14c of the intermediate cylindrical portion 14, and two stepped portions that expand in two stages are formed on the inner diameter side of the lower end portion thereof.

[0038] Also, a valve seat member 40 is fitted and fixed by caulking inside the cylindrical portion 15. Note that the fixing of the valve seat member 40 to the intermediate cylindrical portion 14 may be other than caulking.

[0039] Here, the valve seat member 40 will be described. The valve seat member 40 has an outflow passage 3 penetrating in the axial direction, and is formed in an outer diameter-side stepped cylindrical shape that can be fitted inside the cylindrical portion 15. Further, a tapered valve seat 40a that reduces in diameter downward is formed on the inner diameter side of the upper end of the valve seat member 40.

[0040] On the valve seat 40a of the valve seat member 40, the tapered surface 53a of the valve body 51 can be seated. That is, the valve 50 is constituted by the valve seat 40a and the tapered surface 53a.

[0041] Also, the intermediate cylindrical portion 14 in which the valve body 51 is disposed and the valve seat member 40 having the valve seat 40a define the valve chamber 4.

[0042] Next, the solenoid 80 will be described. The solenoid 80 is mainly composed of a holder 81, a center post 82 as a fixed core, a rod 83, a movable core 84, a can 85, a coil 86, and bearings 87, 88.

[0043] The holder 81 is formed in a stepped cylindrical shape in which the center post 82 is inserted and fixed from the lower side in the axial direction.

[0044] Also, an opening 81a that opens downward is formed in the holder 81.

[0045] The center post 82 is formed in a stepped cylindrical shape from a rigid body that is a magnetic material such as iron or silicon steel.

[0046] The center post 82 includes a cylindrical main body portion 82a that extends in the axial direction. A bearing 87 is inserted and fixed to the upper end of the main body portion 82a from the upper side in the axial direction. Also, a bearing 88 is inserted and fixed to the upper end of the main body portion 82a from the lower side in the axial direction.

[0047] Also, a flange 82b that is continuous with the lower end of the main body portion 82a and protrudes in the outer diameter direction is formed on the center post 82.

[0048] The rod 83 is formed in a cylindrical shape. The rod 83 is inserted through the center post 82 and the bearings 87, 88 and is disposed so as to be reciprocally movable in the axial direction.

[0049] Also, by means of the bearings 87 and 88, the rod 83 is self-aligning and its axial movement is guided. That is, the bearings 87 and 88 constitute the self-aligning structure of the rod 83.

[0050] Further, on the rod 83, at a position above its lower end, an annular groove 83a is formed which is open in the outer diameter direction and recessed in the inner diameter direction. A spring stopper 93, which is a C-shaped thin plate, is externally fitted and fixed to this annular groove 83a. Note that the method of fixing the spring stopper 93 to the rod 83 may be changed as appropriate.

[0051] Also, the upper end of the rod 83 is in contact with the lower end of the movable iron core 84. Thereby, when the solenoid 80 is energized, the rod 83 moves following the movable iron core 84 which moves in the valve closing direction. Along with this, the rod 83 moves the valve body 51 in the valve closing direction, that is, axially downward.

[0052] The cam 85 is formed in a bottomed cylindrical shape and is internally fitted and fixed to an opening which is open on the upper axial side of the holder 81.

[0053] A part of the rod 83 and the movable iron core 84 are arranged movably in the axial direction within the cam 85. Also, the axial movement of the movable iron core 84 is guided by the inner peripheral surface of the cam 85. Note that the movable iron core 84 does not necessarily have to be guided by the cam 85.

[0054] The coil 86 is an exciting coil wound around the center post 82 via a bobbin on the outside.

[0055] Next, the operation of the solenoid valve 1 will be described with reference to FIGS. 3 and 4.

[0056] First, the solenoid valve 1 in the non-energized state will be described. Referring to FIG. 1, in the non-energized state, the valve 50 is in an open state in which the valve body 51 is separated from the valve seat 40a by the biasing force of the coil spring 90, and is in a fully open state.

[0057] Specifically, due to the biasing force of the coil spring 90, the rod 83 is pressed axially upward via the spring stopper 93. As a result, the upper end surface 52a of the valve body 51 is pressed against the ceiling surface 14a of the valve housing 10.

[0058] In other words, the upward movement of the valve body 51 and the rod 83 is restricted by the valve housing 10. In this way, since the valve housing 10 functions as a stopper for holding the position of the valve body 51 during valve opening, the configuration of the solenoid valve 1 becomes simpler compared to a configuration that requires a separate stopper during valve opening.

[0059] Further, the extension of the coil spring 90 is restricted by the bottom surface 12a of the small-diameter cylindrical portion 12 and the spring stopper 93, and it is in a compressed state.

[0060] When the valve 50 is opened, the fluid that has flowed into the valve chamber 4 through each inflow passage 2 flows out of the solenoid valve 1 through the outflow passage 3.

[0061] At this time, since the upper end surface 52a of the valve body 51 is in pressure contact with the ceiling surface 14a of the valve housing 10, the spring chamber 5 is isolated from the valve chamber 4. Therefore, it is difficult for fluid to flow into the spring chamber 5 as much as possible when the valve 50 is opened.

[0062] As a result, it is difficult for contaminants to flow into the spring chamber 5 together with the fluid from the valve chamber 4 during valve opening and damage the functions of the solenoid 80 and the coil spring 90. Therefore, the solenoid valve 1 can control the flow rate and pressure of the fluid stably.

[0063] Further, since the spring chamber 5 is isolated from the valve chamber 4, the fluid flows smoothly from the inflow passage 2 toward the outflow passage 3.

[0064] Further, since the upper end surface 52a of the valve body 51 is in pressure contact with the ceiling surface 14a in the valve housing 10, the valve body 51 can prevent fluid from flowing into the spring chamber 5. For example, while isolating the spring chamber 5 from the valve chamber 4, the valve body 51 stops in a non-contact state with the valve housing 10. Compared with a configuration in which a slight gap is formed between them, it is much more difficult for fluid to flow into the spring chamber 5.

[0065] Also, in a state where the upper end surface 52a of the valve body 51 is in pressure contact with the ceiling surface 14a in the valve housing 10, the groove 52b in the valve body 51 constitutes a passage that communicates the valve chamber 4 and the spring chamber 5 together with the ceiling surface 14a. That is, the configuration of the passage in this embodiment is simple.

[0066] The groove 52b has a throttle function with a sufficiently narrow flow path cross-sectional area. When a pressure difference occurs between the fluid pressure in the valve chamber 4 and the fluid pressure in the spring chamber 5 in a state where the valve chamber 4 and the spring chamber 5 are isolated, the fluid gradually moves from the high-pressure side chamber to the low-pressure side chamber.

[0067] Also, in the solenoid valve 1 of this embodiment in which only one groove 52b is formed, compared with the case where a plurality of grooves 52b are formed, the flow of fluid between the valve chamber 4 and the spring chamber 5 is less likely to occur.

[0068] Therefore, when the valve 50 is opened in the solenoid valve 1, while allowing the movement of fluid to eliminate the pressure difference between the valve chamber 4 and the spring chamber 5 due to the groove 52b, the inflow and outflow of fluid into the spring chamber 5 through the groove 52b are prevented as much as possible.

[0069] Next, the solenoid valve 1 in the energized state will be described. When the electromagnetic force generated by applying current to the solenoid 80 exceeds the biasing force of the coil spring 90 in the energized state (that is, during so-called duty control), the movable iron core 84 is attracted toward the center post 82 side, that is, the lower side in the axial direction.

[0070] As a result, together with the movable iron core 84, the rod 83 and the valve body 51 start to move integrally downward in the axial direction.

[0071] At this time, in the valve opening state of the valve 50, since the differential pressure is reduced by the inflow and outflow of fluid from the valve chamber 4 to the spring chamber 5 through the groove 52b in the valve body 51, the valve body 51 smoothly moves in the valve closing direction at the start of energization.

[0072] Also, when the upper end surface 52a of the valve body 51 is about to separate from the ceiling surface 14a in the valve housing 10, the volume of the space communicating with the spring chamber 5 instantaneously increases. However, since the groove 52b is provided, almost no negative pressure relative to the spring chamber 5 is generated.

[0073] Therefore, immediately after energization, the valve body 51 smoothly moves in the valve closing direction.

[0074] Also, since the spring stopper 93 has a small diameter, it is less likely to receive fluid resistance and can reduce the driving force of the solenoid 80. For example, this is because the spring stopper 93 can have a small diameter compared to the case of using a cylindrical coil spring having the same diameter as the large diameter end 92 of the coil spring 90.

[0075] Also, since the coil spring 90 is conical, the axial length of the spring chamber 5 can be shortened.

[0076] Also, since the valve body 51 and the rod 83 are connected, the rod 83 is centered by the bearings 87, 88, so that the valve body 51 is also centered. For example, if the valve body and the rod are merely in contact, separate centering structures for the rod and the valve body are required. That is, the connected valve body 51 and rod 83 do not need a sliding guide for the valve body 51, and the centering structure can be simplified.

[0077] In addition, in this embodiment, since the coil spring 90 is disposed in the spring chamber 5, the center post 82 and the movable iron core 84 can easily form a sufficient magnetic path without being restricted in shape by the coil spring 90.

[0078] Further, the valve body 51 formed in a bottomed cylindrical shape is lighter than a solid valve body formed in a cylindrical shape. Therefore, the coil spring 90 may have a small biasing force. As a result, the driving force of the solenoid 80 sufficient to resist the biasing force of the coil spring 90 is also reduced.

[0079] The valve 50 decreases in valve opening degree as the valve body 51 moves in the closing direction. Further, when a current equal to or greater than a predetermined value is applied, the valve 50 is closed (see FIG. 4).

[0080] In addition, when the valve 50 is closed, the inflow of fluid into the valve chamber 4 also stops. This makes it difficult for contaminants to get caught between the rod 83 and the bearing 88.

[0081] When the current applied to the solenoid 80 is decreased, the rod 83 is moved in the opening direction by the biasing force of the coil spring 90, and the valve body 51 and the movable iron core 84 are driven accordingly.

[0082] When the current applied to the solenoid 80 becomes less than a specific value or zero, the upper end surface 52a of the valve body 51 abuts against the ceiling surface 14a in the valve housing 10, and the valve is fully opened.

[0083] Just before the upper end surface 52a of the valve body 51 abuts against the ceiling surface 14a in the valve housing 10, although the volume of the space communicating with the spring chamber 5 instantaneously decreases, since the groove 52b is provided, almost no positive pressure relative to the spring chamber 5 is generated.

[0084] As a result, at the end of energization, the valve body 51 smoothly moves in the opening direction and reaches the fully opened state. That is, the solenoid valve 1 can smoothly isolate the valve chamber 4 and the spring chamber 5.

[0085] Also, immediately before the upper end surface 52a of the valve body 51 abuts against the ceiling surface 14a in the valve housing 10, that is, when the valve 50 reaches the fully open state, a fluid flow from the spring chamber 5 toward the valve chamber 4 occurs between the spring chamber 5 and the valve chamber 4. As a result, contaminants are easily discharged from the spring chamber 5.

Embodiment

[0086] Next, the solenoid valve according to Embodiment 2 will be described with reference to FIG. 5. Note that the same components as those shown in Embodiment 1 are denoted by the same reference numerals, and redundant descriptions thereof are omitted.

[0087] As shown in FIG. 5, the valve housing 110 in the solenoid valve 101 is composed of a first divided body 111 and a second divided body 112.

[0088] On the inner diameter side of the first divided body 111, a small-diameter cylindrical portion 12 is formed. Also, on the outer diameter side of the first divided body 111, an annular rib 113 that protrudes outward from the outer peripheral surface at the axial center is formed.

[0089] On the inner diameter side of the second divided body 112, in order from the upper side in the axial direction, a large-diameter cylindrical portion 116 that can be externally fitted to the outer peripheral surface of the first divided body 111, an intermediate cylindrical portion 114 having an inner diameter larger than that of the large-diameter cylindrical portion 116, and a cylindrical portion 115 having an inner diameter slightly smaller than that of the intermediate cylindrical portion 14 are formed.

[0090] The outer end and upper end of the large-diameter cylindrical portion 116 are a thin wall 117 that extends upward. In the assembled state, the thin wall 117 is caulked and inclined in the inner diameter direction.

[0091] The valve chamber 104 is defined by the intermediate cylindrical portion 114 and the first divided body 111.

[0092] The cylindrical portion 115 has an outflow passage 103. Further, at the upper end of the cylindrical portion 115, a valve seat 140a in the form of a tapered surface that tapers downward is formed. The valve 150 is constituted by this valve seat 140a and the tapered surface 53a on the valve body 51.

[0093] The valve housing 110 is assembled by press-fitting it into the large-diameter cylindrical portion 116 until the annular rib 113 of the first split body 111 abuts against the end face that is substantially orthogonal to the thin wall 117 in the second split body 112, clamping the thin wall 117 in the second split body 112, and locking it to the annular rib 113.

[0094] That is, the valve housing 110 is divided into a first split body 111 and a second split body 112 above the intermediate cylindrical portion 114 where the valve body 51 is disposed. Therefore, the valve body 51 can be disposed in the valve chamber 104 without using the valve seat member 40 as in the first embodiment. As a result, it is not necessary to ensure both the strength of the valve seat member 40 and the peripheral wall of the cylindrical portion 15 that supports it. Also, the size of the valve housing 110 can be made smaller compared to the size of the valve housing 10 in the first embodiment.

Embodiment

[0095] Next, the solenoid valve according to Embodiment 3 will be described with reference to FIG. 6. Note that the same reference numerals are given to the same components as those shown in the first and second embodiments, and redundant descriptions are omitted.

[0096] As shown in FIG. 6, the valve housing 210 in the solenoid valve 201 is composed of a first split body 211 and a second split body 212.

[0097] A male thread 211a is formed on the outer peripheral surface of the lower end portion of the first split body 211.

[0098] On the inner diameter side of the second divided body 212, in order from the upper side in the axial direction, an intermediate cylindrical portion 214 that can be externally fitted to the male thread 211a of the first divided body 211 and a cylindrical portion 215 having an inner diameter slightly smaller than that of the intermediate cylindrical portion 14 are formed.

[0099] At the upper end of the intermediate cylindrical portion 214, a female thread 214a that can be screwed into the male thread 211a of the first divided body 211 is formed.

[0100] At the upper end of the cylindrical portion 215, an annular stepped portion 215a that expands in the outer diameter direction is formed. An annular valve seat member 240 is fitted inside the annular stepped portion 215a. The valve 250 is constituted by the valve seat 240a of this valve seat member 240 and the tapered surface 53a of the valve body 51. Incidentally, the valve seat may be directly formed on the second divided body as in the second embodiment.

[0101] Further, the through hole in the valve seat member 240 and the lower side of the annular stepped portion 215a in the cylindrical portion 215 constitute the outflow passage 203.

[0102] The valve chamber 204 is defined by the intermediate cylindrical portion 214, the valve seat member 240, and the first divided body 211.

[0103] The valve housing 210 is assembled by screwing the male thread 211a in the first divided body 211 into the female thread 212a in the second divided body 212.

[0104] Thereby, even if there are tolerances in the parts, by adjusting the dimension of screwing the male thread 211a in the first divided body 211 into the female thread 212a in the second divided body 212, the opening degree of the valve 250 with respect to the current can be made substantially constant. Thereby, in the valve housing 210, an increase in cost due to reducing the tolerances of the parts can be prevented.

[0105] The above has described Examples 1 to 3 of the present invention with reference to the drawings. However, the specific configuration is not limited to these Examples 1 to 3, and even if there are changes or additions within the scope not departing from the gist of the present invention, they are included in the present invention.

[0106] For example, in the above Examples 1 to 3, the spring chamber was described as being defined by the valve housing and the center post. However, it is not limited to this, and it may be defined by the holder and the center post, or may be configured by fixing a bottomed cylindrical member to the valve housing. As long as it can be isolated from the valve chamber by the valve body, the configuration may be appropriately changed.

[0107] Also, in the above Examples 1 to 3, the valve seat was described as being configured by a valve seat member fixed to the valve housing. However, it is not limited to this, and it may be configured in the valve housing.

[0108] Also, in the above Examples 1 to 3, the spring chamber and the valve chamber were described as being isolated by the valve body abutting against the valve housing. However, it is not limited to this. For example, by the movable iron core abutting against the can or the like, a very small gap sufficient to regulate the inflow and outflow of fluid into the spring chamber is formed between the valve housing and the valve body, and it may be configured to be isolated. In such a configuration, it is more preferable that the very small gap functions as a throttle as a passage.

[0109] Also, in the above Examples 1 to 3, the configuration in which the valve body abuts against the valve housing was described. However, an elastic member such as a gasket may be provided on the valve body or the housing, and the elastic member may abut against the mating member in the valve opening state.

[0110] Also, in the above Examples 1 to 3, the groove was described as being formed only one on the valve body. However, it is not limited to this, and a plurality of grooves may be formed. In particular, if the grooves are evenly arranged, it is possible to easily maintain the posture of the valve body when starting to move the valve body that isolates the valve chamber and the spring chamber in the valve closing direction.

[0111] Also, in the first to third embodiments, the groove has been described as being formed in the valve body. However, the present invention is not limited to this, and the groove may be formed in the housing. Further, the groove may be formed in both the valve body and the housing.

[0112] Also, in the first to third embodiments, the passage has been described as being constituted by the groove. However, the present invention is not limited to this, and the passage may be a gap formed by ribs, may be constituted by a through hole, or may be appropriately changed.

[0113] Also, in the first to third embodiments, the spring has been described as being a conical coil spring. However, the present invention is not limited to this, and the spring may be a cylindrical coil spring, may be a leaf spring, or may be appropriately changed.

[0114] Also, in the first to third embodiments, the spring has been described as being a compression spring. However, the present invention is not limited to this, and the spring may be a tension spring as long as it can be biased in the valve opening direction.

[0115] Also, in the first to third embodiments, the coil spring has been described as being in contact with the spring stopper. However, the present invention is not limited to this, and the coil spring may be directly fixed to a rod or the valve body by welding or the like.

[0116] Also, in the first to third embodiments, the rod and the valve body have been described as being separate bodies. However, the present invention is not limited to this, and the rod and the valve body may be integrally formed.

[0117] Also, in the first to third embodiments, the rod has been described as being in contact with the movable iron core. However, the present invention is not limited to this, and the rod and the movable iron core may be connected.

[0118] Also, in the first to third embodiments, the rod and the valve body have been described as being connected. However, the present invention is not limited to this, and the rod and the valve body may not be connected.

[0119] In addition, in the first to third embodiments, the valve body has been described as being formed in a bottomed cylindrical shape, but it is not limited to this, and it may be cylindrical, conical, or may be appropriately changed.

Explanation of Reference Numerals

[0120] 1 Solenoid valve 2 Inflow passage 3 Outflow passage 4 Valve chamber 5 Spring chamber 10 Valve housing 40a Valve seat 50 Valve 51 Valve body 52b Groove (passage) 80 Solenoid 82 Center post (fixed core) 83 Rod 84 Movable core 90 Coil spring (conical coil spring) 91 Small-diameter end 93 Spring stopper

Claims

1. a valve body, a valve seat on which the valve body is seated, a solenoid having a movable iron core, a rod, and a fixed iron core, the solenoid applying a driving force in the valve closing direction to the valve body, a spring that biases the valve body in the valve opening direction, a poppet-type solenoid valve comprising a valve housing that defines a valve chamber in which the valve body and the valve seat are disposed, a spring chamber in which the spring is disposed is defined between the valve chamber and the fixed iron core, the valve body is a solenoid valve that isolates the valve chamber and the spring chamber when the valve is opened.

2. The solenoid valve according to claim 1, wherein the valve body abuts against the valve housing when the valve is opened.

3. The solenoid valve according to claim 1 or 2, wherein a passage that communicates the valve chamber and the spring chamber is provided.

4. The solenoid valve according to claim 3, wherein the passage is constituted by a groove formed in the valve body.

5. the spring is a conical coil spring, The solenoid valve according to any one of claims 1 to 4, wherein the rod is provided with a spring stopper against which the small-diameter end of the spring abuts.

6. The solenoid valve according to any one of claims 1 to 5, wherein the valve body and the rod are connected.

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