Motor valve

Abstract

To provide a motor valve capable of controlling a flow rate at high accuracy while restraining leakage of fluid at the time of closing a valve.SOLUTION: A motor valve 1 has: a valve body 2 including a valve chamber VC housing a valve body unit 40 and having a valve seat; a can 3 coupled to the valve body; a rotor 57 of a rotary-driven motor; and a conversion mechanism 27 for displacing a driving part 22 in an axial line direction according to the rotation angle of the rotor. The valve body unit has a valve shaft 41 coupled to the driving part, and a valve body part 42 relatively movable to the valve shaft in the axial line direction and approaching to and separated from the valve seat. An elastic body 45 is arranged on one of the valve shaft and the valve body to surround the periphery of the valve seat, and a contact part approaching to and separated from the elastic body is arranged on the other of the valve shaft and the valve body.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an electric valve.

Background Art

[0002] Conventionally, an electric valve is assembled, for example, in the middle of a fluid piping system and used to open and close a fluid flow path or control the flow rate. For example, in the electric valve shown in Patent Document 1, a planetary gear reduction mechanism is used to increase the torque of a stepping motor mounted on a valve body and transmit it to the valve element, thereby realizing accurate flow rate control and sealing performance when the valve is closed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in the electric valve of Patent Document 1, the valve element made of metal comes into contact with and separates from the valve seat made of metal to perform the opening and closing valve operation. Therefore, when the valve is closed with foreign matter intervening between the valve seat and the valve element, the foreign matter may be bitten in, and indentations may occur on the sealing surface of the valve seat or the valve element, resulting in fluid leakage when the valve is closed.

[0005] As a countermeasure, it is also an idea to make one of the valve seat and the valve element made of rubber. However, when these materials are changed to rubber, sagging (volume reduction) and the like may occur due to heat or changes over time, and the gap between the valve seat and the valve element during valve opening may change, affecting the adjustment of the fluid flow rate or making it difficult to control the flow rate.

[0006] The present invention has been made in view of such problems, and an object thereof is to provide an electric valve capable of suppressing fluid leakage when the valve is closed and realizing highly accurate flow rate control.

Means for Solving the Problem

[0007] The electric valve of the present invention comprises a valve body including a valve chamber that houses a valve element unit and has a valve seat, a stem connected to the valve body, a rotor of a motor that is rotationally driven, and a conversion mechanism that displaces a drive part in the axial direction according to the rotation angle of the rotor. The valve element unit has a valve shaft connected to the drive part and a valve element part that is axially movable relative to the valve shaft and contacts and separates from the valve seat. An elastic body is disposed on one of the valve shaft and the valve body so as to surround the periphery of the valve seat, and a contact part that contacts and separates from the elastic body is disposed on the other of the valve shaft and the valve body.

Advantages of the Invention

[0008] According to the present invention, it is possible to provide an electric valve that can achieve high-precision flow rate control while suppressing fluid leakage when the valve is closed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0010] Hereinafter, an embodiment of the electric valve according to the present invention will be described with reference to the drawings. In this specification, the rotor side will be described as the upper side, and the valve body side will be described as the lower side. It is assumed that the planetary gear reduction mechanism is a type of planetary gear reduction mechanism.

[0011] [First Embodiment] FIG. 1 is a longitudinal sectional view showing a closed valve state of the electric valve 1 according to the first embodiment of the present invention, and FIGS. 2 to 4 are plan views showing an enlarged view of the vicinity of the valve seat of the electric valve 1 according to the first embodiment. The electric valve 1 of the present embodiment is used, for example, to adjust the refrigerant flow rate in a refrigeration cycle. Let the axis of the electric valve 1 be L.

[0012] The electric valve 1 of the present embodiment includes a valve body 2 having a valve seat 2a formed inside a valve chamber VC, a metal toped cylindrical can 3 fixed to the valve body 2 via an annular body 31, a stator (not shown) provided outside the can 3, and a stepping motor including a rotor 57 provided inside the can 3, a reduction mechanism 6 that decelerates and transmits the rotational torque of the rotor 57, a valve body unit 40 disposed in the valve chamber VC and contacting and separating from the valve seat 2a to control the amount of fluid passing through, and a screw driving member (driving part) 22 that converts the rotational motion of the output gear of the reduction mechanism 6 into a linear motion via a screw feed mechanism (conversion mechanism) 27 and drives the valve body unit 40.

[0013] In the valve body 2, a valve port 16 communicating with the valve chamber VC is formed along the axis L, a first pipe T1 is connected to the valve port 16 side by brazing or the like, and a second pipe T2 is connected to communicate with an opening 18 formed on the side surface of the valve chamber VC by brazing or the like. Let the axis of the second pipe T2 be O. The axis O is orthogonal to the axis L.

[0014] Further, a screw bearing member 13 having a female screw portion 13a formed on the lower end side of the center is inserted into the upper part of the valve chamber VC of the valve body 2 and fixed to the valve body 2 by press-fitting or the like.

[0015] Inside the upper end of the cam 3, a resin shaft support portion 81 is attached. More specifically, the shaft support portion 81 is formed by connecting a cylindrical portion 81a whose upper end surface abuts against the lower surface of the cam 3 and a flange portion 81b that is disposed around the cylindrical portion 81a and whose outer periphery abuts against the inner periphery of the cam 3. A through hole 81c that penetrates vertically is formed coaxially with the axis L at the center of the shaft support portion 81. The inner diameter of the through hole 81c is substantially equal to the outer diameter of the support shaft 8.

[0016] The speed reduction mechanism 6 includes, on the inner peripheral side of the rotor 57, a sun gear 61 integrally formed with the rotor support member 56, a fixed ring gear 62 fixed via a thin-walled cylindrical body 66 that is fixed to the upper portion of the valve body 2 and extends upward, planet gears 63 disposed between the sun gear 61 and the fixed ring gear 62 and meshing with each of them, a carrier 64 that rotatably supports the planet gears 63, and a bottomed cylindrical output gear member 65 having teeth meshing with the planet gears 63 on its inner periphery. These components constitute a planetary gear speed reduction mechanism. The number of teeth of the fixed ring gear 62 is set to be different from the number of teeth of the output gear member 65.

[0017] The metal support shaft 8 penetrates through the rotor support member 56 and the sun gear 61 and is rotatably held together with them. The upper end of the support shaft 8 is fitted into the through hole 81c of the shaft support portion 81 attached to the cam 3 and is supported so as to be movable in the rotational direction and the direction of the axis L.

[0018] At the center of the bottom of the output gear member 65, the upper part of the stepped cylindrical output shaft portion 29 formed on the upper part of the screw drive member 22 is press-fitted. The lower end of the support shaft 8 is press-fitted into the upper opening of the output shaft portion 29, and the output gear member 65, the support shaft 8, and the output shaft portion 29 are configured to rotate integrally.

[0019] The male screw portion 22a formed on the lower part of the screw drive member 22 is screwed into the female screw portion 13a of the screw bearing member 13. The rotational movement of the output gear member 65 (i.e., the rotor 57) is converted into linear movement along the axis L by a screw feed mechanism (conversion mechanism) 27 composed of the male screw portion 22a and the female screw portion 13a.

[0020] A slit 29a is formed at the lower end of the output shaft portion 29, and a blade 22b protruding along the axis L is formed at the upper end of the screw drive member 22. The slit 29a and the blade 22b are slidably engaged with each other. Thereby, the output shaft portion 29 is integrally rotatably connected to the screw drive member 22. When the output gear member 65 (rotor 57) rotates, the output shaft portion 29 and the screw drive member 22 rotate integrally, but are relatively linearly movable along the axis L.

[0021] When the output gear member 65 (rotor 57) rotates, the output gear member 65 and the screw drive member 22 rotate integrally and linearly move along the axis L with respect to the valve body 2. In response to the lifting of the output gear member 65, the carrier 64 and the planetary gear 63 placed on the bottom surface of the output gear member 65 also move up and down integrally with the support shaft 8.

[0022] The lower end of the ball joint 25 composed of the ball 23 and the ball seat 24 abuts on the upper end of the hollow cylindrical spring support member 28 coaxially press-fitted on the upper end of the valve shaft 41 of the valve body unit 40. The cylindrical spring case 19 disposed around the valve body unit 40 and the spring support member 28 is continuously provided with a diameter-expanded portion 19a, a diameter-reduced portion 19b, and an upper end flange portion 19c extending radially outward from the upper end of the diameter-expanded portion 19a. The upper end flange portion 19c is engaged with the inner peripheral step portion of the valve body 2 and is fixedly held by the screw bearing member 13. The diameter-reduced portion 19b slidably holds the outer periphery of the valve shaft 41 of the valve body unit 40.

[0023] The compression coil spring 26 has its lower end abutted on the step portion between the diameter-expanded portion 19a and the diameter-reduced portion 19b, and its upper end engaged with the spring support member 28, and is disposed in a compressed state, thereby biasing the valve body unit 40 in the valve-opening direction at all times.

[0024] The linear motion of the screw drive member 22 is transmitted to the shaft-like valve body unit 40 via the ball joint 25 and the spring support member 28. Thereby, the valve body unit 40 is guided by the spring case 19 and moves in the direction of the axis L.

[0025] The valve body unit 40 is composed of a metal valve shaft 41 and a metal valve body portion 42. The valve shaft 41 coaxially has a small-diameter portion 41a and a large-diameter portion 41b having a larger diameter than the small-diameter portion 41a. The upper end of the small-diameter portion 41a is fitted into the inner circumference of the spring support member 28 by press-fitting, and the outer circumference of the small-diameter portion 41a is slidably fitted to the inner circumference of the reduced-diameter portion 19b. A cylindrical recess 41c is formed in the lower end (the surface facing the valve seat 2a) of the large-diameter portion 41b.

[0026] In FIGS. 2 to 4, on the lower end side of the recess 41c, an enlarged-diameter first inner peripheral portion 41d and a second inner peripheral portion 41e having a larger diameter than the first inner peripheral portion 41d are formed, and the thin-walled peripheral wall of the second inner peripheral portion 41e serves as a caulking portion 41f.

[0027] The substantially cylindrical valve body portion 42 coaxially has a first cylindrical portion 42a having an outer diameter smaller than the inner diameter of the recess 41c, a flange portion 42b having an outer diameter substantially the same as the inner diameter of the recess 41c, a second cylindrical portion 42c having an outer diameter larger than the outer diameter of the first cylindrical portion 42a, and a frustum-shaped tapered portion 42d that reduces in diameter downward.

[0028] A coil spring 44 is disposed between the inner circumference of the recess 41c and the first cylindrical portion 42a such that the upper end abuts against the bottom surface of the recess 41c and the lower end abuts against the upper surface of the flange portion 42b. The coil spring 44 biases the valve body portion 42 downward with respect to the bottom surface of the recess 41c.

[0029] A thin-walled cylindrical retaining member 43 is press-fitted into the first inner peripheral portion 41d. There is a gap between the inner circumference of the retaining member 43 and the second cylindrical portion 42c of the valve body portion 42.

[0030] In a state where the upper end of the retaining member 43 abuts against the stepped portion between the first inner peripheral portion 41d and the second inner peripheral portion 41e, an annular space is formed between the outer periphery of the retaining member 43 and the inner periphery of the second inner peripheral portion 41e, and an annular elastic body 45 made of rubber or resin is attached to this space. When attached to this space, the elastic body 45 elastically deforms and thus adheres closely to the outer periphery of the retaining member 43 and the inner periphery of the second inner peripheral portion 41e. As the material of the elastic body 45, HNBR, PTFE, etc. can be used, but it is not limited thereto.

[0031] Before the valve body unit 40 is assembled, the caulking portion 41f of the valve shaft 41 is cylindrical. When assembling, the coil spring 44 is disposed around the first cylindrical portion 42a of the valve body portion 42, and while maintaining this state, the valve body portion 42 is pushed toward the recess 41c of the valve shaft 41, and further, the retaining member 43 is press-fitted onto the first inner peripheral portion 41d. Thereafter, the elastic body 45 is disposed between the outer periphery of the retaining member 43 and the inner periphery of the second inner peripheral portion 41e, and the lower end of the caulking portion 41f is plastically deformed radially inward, whereby the valve body unit 40 is assembled. Note that the elastic body 45 may be attached to the valve shaft 41 using an adhesive.

[0032] The metal valve body 2 has an edge-shaped valve seat 2a at the intersection of the bottom surface of the valve chamber VC and the valve port 16. The tapered portion 42d of the valve body portion 42 can be seated on the entire circumference of the valve seat 2a.

[0033] Further, the valve body 2 has an annular ridge portion (contact portion) 2b that is disposed so as to surround the periphery of the valve seat 2a and projects upward from the bottom surface of the valve chamber VC. The ridge portion 2b has a tapered inner peripheral surface 2c that expands in diameter upward and a cylindrical outer peripheral surface 2d, and the upper end 2e with a reduced radial width can contact the elastic body 45 on the entire circumference on the radially outer side (valve chamber VC side) of the valve seat 2a.

[0034] (Operation of the electric valve) FIG. 5 is a flow rate characteristic diagram of the electric valve according to the present embodiment, which is shown as a graph with the flow rate on the vertical axis and the valve opening degree (axial direction position of the valve shaft 41) on the horizontal axis. However, the scale on the vertical axis may be different from the actual one. In addition, in the flow rate characteristic diagram of FIG. 5, a schematic diagram showing the relative positional relationship between the valve body portion 42 and the valve seat 2a is also shown. Here, it is assumed that the second pipe T2 side is the high-pressure side and the first pipe T1 side is the low-pressure side. However, the second pipe T2 side may be the low-pressure side and the first pipe T1 side may be the high-pressure side.

[0035] In the state shown in FIG. 2, the valve shaft 41 of the valve body unit 40 is at the lowermost position, the coil spring 44 is compressed, and the bottom surface of the concave portion 41c abuts on the upper end of the valve body portion 42. For this reason, the outer peripheral surface of the tapered portion 42d seats on the valve seat 2a by the downward pressing force applied from the valve shaft 41, and the upper end 2e of the protrusion 2b abuts on the lower surface of the elastic body 45. There is a gap between the lower surface of the flange portion 42b of the valve body portion 42 and the upper end of the retaining member 43.

[0036] At this time, since the lower surface of the elastic body 45 is appropriately elastically deformed, regardless of the component accuracy, the state where the upper end 2e of the protrusion 2b abuts on the lower surface of the elastic body 45 can be maintained in a state where the outer peripheral surface of the tapered portion 42d seats on the valve seat 2a.

[0037] When the metal valve body portion 42 seats on the metal valve seat 2a, a slight gap may occur between the two, which may cause fluid leakage. According to the present embodiment, even if a slight gap occurs between the valve body portion 42 and the valve seat 2a in the closed valve state, the state where the upper end 2e of the protrusion 2b abuts on the lower surface of the elastic body 45 is maintained, so that fluid does not flow from the valve chamber VC to the valve seat 2a side. Such a state is referred to as a completely closed valve region A shown in FIG. 5.

[0038] In the completely closed valve region A, the flow of fluid from the valve chamber VC to the valve port 16 is blocked. For this reason, the movement of fluid between the second pipe T2 and the first pipe T1 is restricted.

[0039] When the rotor 57 of the stepping motor is rotationally driven by supplying power to the stator from the fully closed valve region A, the rotational torque of the rotor 57 is transmitted via the rotor support member 56 to the sun gear 61 of the speed reduction mechanism 6, and the rotational torque reduced at a predetermined reduction ratio is output from the output gear member 65. The rotational torque of the output gear member 65 is transmitted to the output shaft portion 29.

[0040] The rotational motion of the output shaft portion 29 is converted into linear motion by the screw feed mechanism 27, whereby the output shaft portion 29 rises in the axial direction together with the valve shaft 41 of the valve body unit 40. Here, when the valve shaft 41 rises, the elastic body 45 also rises, but as the elastic body 45 rises, the contact portion at the upper end 2e of the protrusion 2b returns from elastic deformation. However, while the contact state with the upper end 2e is maintained, the flow of fluid from the valve chamber VC to the valve port 16 is blocked.

[0041] As the valve shaft 41 rises, the upper end of the valve body portion 42 separates from the bottom surface of the recess 41c. However, since the valve body portion 42 is pressed downward against the valve shaft 41 by the coil spring 44, the seating state between the valve body portion 42 and the valve seat 2a is maintained.

[0042] When the valve shaft 41 rises to the first position P1, as shown in FIG. 3, the lower surface of the elastic body 45 separates from the upper end 2e of the protrusion 2b, and the fully closed valve region A ends. As a result, the fluid in the valve chamber VC can move beyond the protrusion 2b toward the valve seat 2a side, but due to the pressing force of the coil spring 44, the seating state between the valve body portion 42 and the valve seat 2a remains maintained.

[0043] At this time, when there is a slight gap between the valve body portion 42 and the valve seat 2a, fluid flows from the valve chamber VC side to the valve port 16 through the gap, but the amount is slight. Such a state is called the boundary region B.

[0044] Furthermore, the valve shaft 41 rises, and after the lower surface of the flange portion 42b of the valve body portion 42 abuts against the upper end of the retaining member 43, the valve body portion 42 rises together with the valve shaft 41. When the valve shaft 41 rises to the second position P2, the valve body portion 42 separates from the valve seat 2a, and the boundary region B ends, and the flow rate control region C starts. In the flow rate control region C shown in FIG. 4, fluid flows from the valve chamber VC toward the valve port 16 at a flow rate corresponding to the gap between the valve body portion 42 and the valve seat 2a determined by the axial position of the valve shaft 41. Therefore, the movement of a predetermined flow rate of fluid between the second pipe T2 and the first pipe T1 is allowed.

[0045] From the open valve state, by supplying power to the stator with reverse characteristics, the rotor 57 rotates in the reverse direction. Therefore, the valve shaft 41 is lowered by an operation opposite to the above, the valve body portion 42 is seated on the valve seat 2a, and then the upper end 2e of the protrusion 2b is brought into contact with the lower surface of the elastic body 45, so that it is possible to return to the fully closed valve region A.

[0046] According to the present embodiment, after the valve body portion 42 is seated on the valve seat 2a, the bottom surface of the concave portion 41c abuts against the upper end of the valve body portion 42, so that excessive deformation of the elastic body 45 against which the upper end 2e of the protrusion 2b abuts can be suppressed, sagging of the elastic body 45 can be suppressed, and the fully closed valve region A can be stably ensured over a long period of time. Further, even if the elastic body 45 is deformed due to changes over time or the like, as long as the protrusion 2b abuts and the elastic body 45 is elastically deformed, the flow of fluid can be blocked.

[0047] Also, when foreign matter is mixed in the fluid, it is highly likely that biting occurs between the upper end 2e of the protrusion 2b and the elastic body 45. In such a case, since the elastic body 45 is elastically deformed, even if foreign matter is bitten between the upper end 2e and the elastic body 45, fluid leakage is blocked. Further, when the upper end 2e and the elastic body 45 are separated, the foreign matter is washed away by the fluid, so that the foreign matter is suppressed from staying at the same location. Therefore, it is possible to provide the electric valve 1 that can realize highly accurate flow rate control while suppressing fluid leakage during valve closing.

[0048] (Second Embodiment) FIG. 6 is a view similar to FIG. 2 showing a closed valve state of an electric valve according to a modified example of the second embodiment. In the present embodiment, the valve shaft 41A of the valve body unit 40A and the configuration of the valve body 2A are different, and since the other configurations are the same as those of the above-described embodiment, duplicate explanations are omitted.

[0049] The valve shaft 41A of the present embodiment has an annular ridge portion 41Ag at its lower end. The inner peripheral surface of the ridge portion 41Ag is configured by the first inner peripheral portion 41d into which the retaining member 43 is press-fitted extending to the lower end, and the outer peripheral surface of the ridge portion 41Ag is a tapered outer peripheral surface 41Ah that decreases in diameter downward from near the lower end. Further, the ridge portion 41Ag has an annular lower end 41Af.

[0050] The valve body 2A has an annular groove 2Af at the bottom surface of the valve chamber VC around the valve seat 2a. An elastic body 45 is disposed in the annular groove 2Af.

[0051] Also in the present embodiment, in the fully closed valve region A, the outer peripheral surface of the tapered portion 42d seats on the valve seat 2a, and the lower end 41Af of the ridge portion 41Ag abuts on the upper surface of the elastic body 45.

[0052] On the other hand, when the valve shaft 41 rises to the first position P1 (see FIG. 5), the lower end 41Af of the ridge portion 41Ag separates from the upper surface of the elastic body 45, the fully closed valve region A ends, and the boundary region B starts. In the boundary region B, the fluid in the valve chamber VC can move beyond the ridge portion 41Ag toward the valve seat 2a side, but due to the pressing force of the coil spring 44, the seating state between the valve body portion 42A and the valve seat 2a is maintained.

[0053] Furthermore, when the valve shaft 41A further rises and rises to the second position P2 (see FIG. 5), the valve body portion 42 separates from the valve seat 2a, the boundary region B ends, and the flow control region C starts. In the flow control region C, the fluid flows from the valve chamber VC toward the valve port 16 at a flow rate corresponding to the gap between the valve body portion 42 and the valve seat 2a. For this reason, the movement of a predetermined flow rate of fluid between the second pipe T2 and the first pipe T1 is allowed.

[0054] Note that the present invention is not limited to the above-described embodiments. Within the scope of the present invention, any component of the above-described embodiments can be modified. Also, addition or omission of any component in the above-described embodiments is possible. For example, instead of the planetary gear reduction mechanism, a reduction mechanism composed of a gear pair may be provided. Or, an electric valve without a reduction mechanism is also applicable to the present invention.

[0055] This specification includes the disclosure of the following invention. (First aspect) A valve body including a valve chamber that houses a valve body unit and has a valve seat, a stem connected to the valve body, a rotor of a motor that is rotationally driven, and a conversion mechanism that displaces a drive part in the axial direction according to the rotation angle of the rotor. The valve body unit has a valve stem connected to the drive part and a valve body part that is axially movable relative to the valve stem and contacts and separates from the valve seat. An elastic body is disposed on one of the valve stem and the valve body so as to surround the periphery of the valve seat, and an abutting part that contacts and separates from the elastic body is provided on the other of the valve stem and the valve body. An electric valve characterized by the above.

[0056] (Second aspect) An elastic body is disposed on the valve stem, and an annular ridge is formed on the valve body part as the abutting part. The electric valve according to the first aspect, characterized by the above.

[0057] (Third aspect) An elastic body is disposed on the valve body, and an annular ridge is formed on the valve stem as the abutting part. The electric valve according to the first aspect, characterized by the above.

[0058] (Fourth aspect) The electric valve according to any one of the first to third aspects, characterized by having a coil spring that biases the valve body part in a direction toward the valve seat with respect to the valve stem. The electric valve according to any one of the first to third aspects, characterized by the above.

[0059] (Fifth Aspect) The valve body portion is disposed within a recess facing the valve seat side of the valve shaft, and a retaining member for preventing the valve body portion from detaching from within the recess is disposed in the recess. An electric valve according to a fourth aspect, characterized by the above.

[0060] (Sixth Aspect) When the valve shaft moves in a direction away from the valve seat, after the elastic body separates from the contact portion, the valve body portion separates from the valve seat. An electric valve according to any one of the first to fifth aspects, characterized by the above.

[0061] (Seventh Aspect) After the valve body portion separates from the valve seat, control of the fluid flowing through the gap between the valve body portion and the valve seat is performed according to the axial position of the valve shaft. An electric valve according to any one of the first to sixth aspects, characterized by the above.

Description of Reference Numerals

[0062] 1 Electric valve 2, 2A Valve body 3 Cam 40 Valve body unit 41, 41A Valve shaft 42 Valve body portion 43 Retaining member 44 Coil spring 45 Elastic body 6 Reduction mechanism 8 Support shaft VC Valve chamber T1 First pipe T2 Second pipe

Claims

1. A valve body including a valve chamber that houses a valve body unit and has a valve seat, a cam connected to the valve body, a rotor of a motor that is rotationally driven, and a conversion mechanism that displaces a drive unit in the axial direction according to the rotation angle of the rotor, wherein the valve body unit has a valve shaft connected to the drive unit and a valve body portion that is axially relatively movable with respect to the valve shaft and contacts and separates from the valve seat, an elastic body is disposed on one of the valve shaft and the valve body so as to surround the periphery of the valve seat, and a contact portion that contacts and separates from the elastic body is disposed on the other of the valve shaft and the valve body, characterized in that it is an electric valve.

2. An elastic body is disposed on the valve shaft, and an annular ridge portion is formed on the valve body portion as the contact portion, characterized in that it is the electric valve according to Claim 1.

3. An elastic body is disposed on the valve body, and an annular ridge portion is formed on the valve shaft as the contact portion, characterized in that it is the electric valve according to Claim 1.

4. having a coil spring that biases the valve body portion in a direction toward the valve seat with respect to the valve shaft, characterized in that it is the electric valve according to Claim 1.

5. The valve body portion is disposed in a recess facing the valve seat side of the valve shaft, and a retaining member that prevents the valve body portion from separating from the recess is disposed in the recess, characterized in that it is the electric valve according to Claim 4.

6. When the valve shaft moves in a direction away from the valve seat, after the elastic body separates from the contact portion, the valve body portion separates from the valve seat, characterized in that it is the electric valve according to Claim 1.

7. After the valve body portion separates from the valve seat, control of the fluid flowing through the gap between the valve body portion and the valve seat is performed according to the axial position of the valve shaft, characterized in that it is the electric valve according to Claim 6.

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