CN110617336B

CN110617336B - Electric valve and refrigeration cycle system

Info

Publication number: CN110617336B
Application number: CN201910465576.8A
Authority: CN
Inventors: 村田雅弘; 竹田刚; 北见雄希
Original assignee: Saginomiya Seisakusho Inc
Current assignee: Saginomiya Seisakusho Inc
Priority date: 2018-06-19
Filing date: 2019-05-30
Publication date: 2021-05-25
Anticipated expiration: 2039-05-30
Also published as: CN110617336A; JP2021105453A; JP6864652B2; JP7141484B2; JP2019218997A

Abstract

The invention provides an electric valve which reliably installs a sealing component on a valve core guiding part to improve the sealing performance of the sealing component and has good assembly performance, and a refrigeration cycle system using the electric valve. The valve includes a side wall extending in a central axis direction in a valve body and receiving a part of a rotor side of a valve body on an inner diameter side, a composite type seal member attached to an inner periphery of the side wall on the valve port side and formed by joining a seal portion and a biasing portion biasing the seal portion, and a holding portion disposed on the side wall on the valve port side of the seal member and holding the seal member, wherein an engaging portion engaging with an upper surface of the seal member is provided on the valve port side of the side wall, the seal member is disposed between the engaging portion and the holding portion in the central axis direction, and the holding portion is fixed to the side wall in the central axis direction in an abutting manner by a step formed on at least one of the inner periphery of the side wall and an outer periphery of the holding portion.

Description

Electric valve and refrigeration cycle system

Technical Field

The present invention relates to an electric valve and a refrigeration cycle system using the same.

Background

Conventionally, a fluid control valve used in a large-sized combination air conditioner or a large-sized refrigerator is known. In this fluid control valve, from the background of rationalizing control equipment such as integrating a plurality of electrically operated valves used for flow rate control into one, performance that has a large diameter and can exhibit good operability even when a high pressure difference occurs is desired. However, in the flow rate control with a large diameter, the load on the valve element due to the pressure difference is large as compared with the thrust of the screw due to the torque of the magnet, and a large driving force is required to operate the valve element.

Therefore, in order to improve the operability of such a valve body, a pressure balance mechanism described below is employed (for example, see patent document 1). Specifically, in the motor-operated valve 101 shown in fig. 8, a back pressure chamber 129 is defined above the valve chamber 107, the pressure in the valve port 119 is introduced into the back pressure chamber 129 through a communication passage 124 provided in the valve body 120, and the force generated by the pressure difference between the depression force (force acting in the valve closing direction) and the lift force (force acting in the valve opening direction) acting on the valve body 120 in the valve-closed state is cancelled by the pressure (back pressure) in the back pressure chamber 129, thereby reducing the load on the valve body 120.

In the motor-operated valve 101 using this pressure balancing mechanism, a sealing member 137 is interposed between the valve body 120 and the valve body guide 172 in order to hermetically separate the back pressure chamber 129 from the valve chamber 107. Here, in the motor-operated valve 101 described above, an external seal structure is adopted in which the seal member 137 is attached to the valve body 120 side and abuts against the inner peripheral surface of the valve body guide portion 172, but the arrangement of the seal member 137 may not be the external seal structure. For example, an inner seal structure in which the seal member 137 is attached to the valve body guide portion 172 side and abuts against the outer peripheral surface of the valve body 120 is also conceivable.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-180639

Disclosure of Invention

Problems to be solved by the invention

However, when the inner seal structure is employed, the number of components constituting the motor-operated valve is increased as compared with the case of employing the outer seal structure, and there is a problem that the assembling property becomes complicated.

Further, it is an object of the present invention to reliably attach a seal member to a valve body guide portion so as not to cause leakage or increase sliding resistance, which affects sealing performance.

The invention aims to provide a motor-operated valve which can reliably mount a sealing component on a valve core guiding part to improve the sealing performance of the sealing component and has good assembly performance, and a refrigeration cycle system using the motor-operated valve.

Means for solving the problems

[1] The electric valve of the invention converts the rotary motion of a rotor contained in a housing into a linear motion by the thread connection of a male thread member and a female thread member, moves a valve body contained in a valve body in the central axis direction of the valve body based on the linear motion, and introduces the pressure in the valve port into a back pressure chamber provided above the valve body,

the electrically operated valve is characterized by comprising:

a side wall extending in the valve body in the central axis direction and receiving a part of the valve element on the rotor side on an inner diameter side;

a composite seal member which is attached to an inner periphery of the side wall on the valve port side and is formed by joining a seal portion and a biasing portion which biases the seal portion; and

a holding portion that is disposed on the side wall on the valve port side of the seal member and holds the seal member,

an engaging portion that engages with an upper surface of the seal member is provided on the side wall on the valve port side, the seal member is disposed between the engaging portion and the holding portion in the central axis direction,

the holding portion is held in contact with and fixed to the side wall in the central axis direction by a step formed on at least one of an inner peripheral surface of the side wall and an outer peripheral surface of the holding portion.

In this way, by fixing the holding portion to the side wall by the step so as to abut in the central axis direction, the seal member can be attached to the side wall at a correct position, and the sealing property of the seal member can be improved. Further, at the time of assembly, there is no need to manage the insertion amount of the holding portion in accordance with the load and the position, and the assemblability of the motor-operated valve can be maintained even when the seal member is assembled to the inner periphery of the side wall.

[2] In addition, the electrically operated valve of the present invention is characterized in that,

a guide flange protruding to the outer diameter side is formed on the holding portion,

the holding portion is fixed to the side wall by bringing the step formed on the outer peripheral surface by the guide flange into contact with the lower end portion of the side wall.

In this way, the retaining portion is fixed to the side wall by bringing the step formed in the guide flange into contact with the lower end of the side wall, and the retaining portion can be accurately fitted to the predetermined position of the valve body guide portion.

[3] In addition, the electrically operated valve of the present invention is characterized in that,

the holding portion is fixed to the side wall by bringing an upper end surface of the holding portion into contact with the step formed on the inner peripheral surface of the side wall.

In this way, even when the holding portion is fixed to the side wall by abutting the holding portion against the step formed on the inner peripheral surface of the side wall, the holding portion can be accurately fitted to the predetermined position of the spool guide portion.

[4] In addition, the electrically operated valve of the present invention is characterized in that,

the holding portion restricts a radial position of the valve element on the valve port side.

This suppresses the amplitude of the radial oscillation of the valve body from increasing. Therefore, for example, valve leakage when the valve body is seated on the seat portion can be reduced.

[5] In addition, the electrically operated valve of the present invention is characterized in that,

the holding portion includes an extension portion that extends toward the valve port side with an outer diameter of the outer peripheral surface smaller than a diameter of a portion inserted into the sidewall.

In this way, by providing the extension portion having a small outer diameter on the outer peripheral surface, the fluid flowing into the valve chamber from the pipe joint can be guided to the valve port without reducing the flow rate of the fluid.

[6] In addition, the electrically operated valve of the present invention is characterized in that,

the valve body further includes an urging spring for urging the valve element.

In this way, by providing the biasing spring that biases the valve element, the contact surface between the thread ridges of the male screw and the female screw can be kept constant.

[7] In addition, the electrically operated valve of the present invention is characterized in that,

the urging spring is formed so that the inner diameter is larger than the diameter of the sliding surface of the valve element, and urges the valve element in the central axis direction in the valve main body.

In this way, since the valve body is biased by the biasing spring having a large inner diameter, the inclination of the axis of the valve body with respect to the central axis can be suppressed.

[8] In addition, the electrically operated valve of the present invention is characterized in that,

at least a part of the valve body is housed inside the biasing spring.

This can shorten the length of the entire motor-operated valve in the central axis direction.

[9] In addition, the electrically operated valve of the present invention is characterized in that,

an inner flange protruding to an inner diameter side is formed on the rotor side of the side wall,

a valve flange projecting outward in the outer diameter direction is disposed on the valve body,

the urging spring is disposed between the inner flange and the valve flange.

In this way, by disposing the upper end of the urging spring on the inner flange of the side wall, the radial position of the urging spring can be maintained so that the shaft of the urging spring does not incline with respect to the central axis. Further, by disposing the lower end of the biasing spring on the valve flange that protrudes toward the outer diameter side of the valve body, it is possible to suppress the occurrence of an excessive sliding resistance in the biasing spring due to the outer periphery of the biasing spring coming into contact with the valve body guide portion.

[10] In addition, the electrically operated valve of the present invention is characterized in that,

a convex portion that protrudes toward the inner diameter side of the side wall and locally reduces the inner diameter of the side wall in the central axis direction is formed on the fixed end side of the urging spring,

a wall portion extending in the central axis direction on the inner diameter side of the biasing spring is formed on the movable end side of the biasing spring.

In this way, the convex portion protruding toward the inner diameter side of the side wall is formed on the fixed end side of the biasing spring, and the outer diameter side of the biasing spring is guided on the fixed end side, so that the biasing spring is suitable for a case where the diameter of the biasing spring is large. Further, the inner diameter side of the biasing spring is guided to the movable end side by forming a wall portion on the inner diameter side of the movable end of the biasing spring.

Further, by projecting the convex portion inward in the radial direction, the radial position of the urging spring is regulated, and the radial position can be prevented from being displaced, thereby improving the controllability of the electric valve. Further, since the radial position of the biasing spring is partially restricted by the convex portion over the entire length, the biasing spring can be prevented from sliding excessively along the inner peripheral surface of the valve body guide portion, as compared with the case where the radial position is restricted over the entire length.

[11] In addition, the electrically operated valve of the present invention is characterized in that,

the seal member is formed using a lip seal having a lip portion that slides with respect to the valve body.

By using the seal member having the lip seal in this manner, the amount of crush of the seal member can be determined according to the member size of the side wall and the holding portion, and the amount of crush of the seal member can be stabilized.

[12] The refrigeration cycle system of the present invention is a refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, and is characterized by using the electrically operated valve.

Such an electrically operated valve is preferable in a refrigeration cycle because the opening degree of the valve can be reliably adjusted as a control valve to control the flow rate.

The effects of the invention are as follows.

According to the present invention, it is possible to provide a motor-operated valve and a refrigeration cycle system using the motor-operated valve, in which the sealing member can be reliably attached to the valve body guide portion to improve the sealing performance of the sealing member and which is excellent in assembly performance.

Drawings

Fig. 1 is a schematic cross-sectional view of an electrically operated valve according to an embodiment.

Fig. 2 is an enlarged view of a portion above a valve body guide portion in the motor-operated valve according to the embodiment.

Fig. 3 is an enlarged view of the vicinity of the sealing member in the motor-operated valve according to the embodiment.

Fig. 4 is an enlarged view of a valve body guide portion in the electric valve according to another embodiment.

Fig. 5 is an enlarged view of a holding portion in the motor-operated valve according to another embodiment.

Fig. 6 is an enlarged view of a valve body in an electric valve according to another embodiment.

Fig. 7 is an enlarged view of a seal member in the electric valve according to another embodiment.

Fig. 8 is a schematic cross-sectional view showing a sealing portion of a conventional motor-operated valve.

Description of the symbols

2-an electric valve, 4-a rotor, 6-a valve shaft holder, 6 a-a cylindrical small diameter portion, 6 b-a cylindrical large diameter portion, 6 c-an engaging portion, 6 d-an internal thread, 6 f-a flange portion, 6 g-an upper opening portion, 6 h-a housing chamber, 6 k-an extending portion, 11-a valve chamber, 12-a first pipe joint, 15-a second pipe joint, 16-a valve seat portion, 16 a-a valve port, 17-a valve core, 17 a-a head portion, 17 b-a sliding cylinder portion, 17 c-a connecting portion, 17 d-a space, 17 k-a hole portion, 17 l-a through hole, 18-a valve guide, 18 a-a through hole, 21-a top portion, 27-a valve spring, 28-a back pressure chamber, 29-a spring seat metal component, 29 a-a valve flange, 29 b-a wall portion, 30-a valve body, 32-an urging spring, 33-a bush component, 36-a valve shaft, 41a male thread, 41 c-a protrusion, 48-a sealing member, 48 a-an L-shaped annular packing, 48 b-a reinforcing plate, 48 c-a plate spring, 48 f-an O-ring, 48 j-a lip, 51-a pressure equalizing hole, 52-a guide support, 53-a cylindrical portion, 54-an umbrella-shaped portion, 60-a housing, 65-a cylindrical member, 66-a rotor housing chamber, 70-a gasket, 72-a spool guide portion, 72 a-a side wall, 72 b-a flange, 72 c-a holding portion, 72 c' -an upper end surface of the holding portion, 72 j-a flange portion, 72 k-an intermediate cylindrical portion, 72L-a lower end portion, 72 m-a protrusion, 72 u-an inner flange, 72 x-a step, 72 y-a step, 72 z-a lower end, 72 β -a flange portion, 73 a-an upper outer circumferential surface, 73 b-a lower outer circumferential surface, 73 f-a guide flange, 73 z-a step, 74a upper inner circumferential surface, 74 b-a lower inner circumferential surface, 75-an extension, 78-claw portion, 82-fixing member, 84-spring, 92-spool guide portion, 101-electric valve, 107-valve chamber, 119-valve port, 120-spool, 124-conduction path, 129-back pressure chamber, 137-sealing member, 172-spool guide portion, M-center axis, L-center axis.

Detailed Description

Hereinafter, an electrically operated valve according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a schematic cross-sectional view showing an electric valve 2 according to an embodiment. In the present specification, "upper" or "lower" is defined in the state of fig. 1. That is, the rotor 4 is located above the valve body 17.

In the motor-operated valve 2, a valve main body 30 is integrally connected by welding or the like to a lower side of an opening side of a cylindrical cup-shaped housing 60 made of metal.

Here, the valve main body 30 is made of metal such as stainless steel, and has a valve chamber 11 as a space formed outside the valve body 17. A first pipe joint 12 made of, for example, stainless steel or copper and directly communicating with the valve chamber 11 is fixedly attached to a side surface of the valve main body 30. Further, a valve seat portion 16 is assembled inside the lower portion of the valve main body 30, and a valve port 16a having a circular cross section is formed to penetrate through the valve seat portion 16. The port 16a is provided directly below the valve body 17 in the direction coaxial with the valve body 17. A second pipe joint 15 made of, for example, stainless steel or copper, which communicates with the first pipe joint 12 via the valve port 16a and the valve chamber 11, is fixed to the valve seat portion 16.

A rotatable rotor 4 is housed in the inner periphery of the housing 60, and a valve shaft 41 is disposed in the axial core portion of the rotor 4 via a bush member 33. Further, the rotor 4 is formed of a material having magnetism, such as a resin material containing magnetic powder. The hub member 33 and the valve shaft 41 are both made of metal such as stainless steel, for example, and the valve shaft 41 coupled to the hub member 33 moves in the vertical direction integrally with the rotor 4 while rotating. A male screw 41a is formed on the outer peripheral surface of the valve shaft 41 near the intermediate portion. In the present embodiment, the valve shaft 41 functions as a male screw member. The valve element 17 can be moved toward or away from the valve port 16 a.

A stator including a yoke, a bobbin, a coil, and the like, which are not shown, is disposed on the outer periphery of the housing 60, and the rotor 4 and the stator constitute a stepping motor.

A guide support 52 is fixed to the top surface of the housing 60. The guide support 52 has a cylindrical portion 53 and an umbrella portion 54 formed on the upper end side of the cylindrical portion 53, and is integrally formed by press working the entire body. The umbrella 54 is shaped substantially the same as the top inner side of the housing 60.

A cylindrical member 65 serving also as a guide for the valve shaft 41 is fitted into the cylindrical portion 53 of the guide support 52. The cylindrical member 65 is made of metal, synthetic resin, or a member subjected to surface treatment, and rotatably holds the valve shaft 41.

The valve shaft holder 6 is fixed to the valve body 30 at a position below the bush member 33 of the valve shaft 41 so as to be relatively non-rotatable, and the valve shaft holder 6 constitutes a screw feed mechanism a with the valve shaft 41 as described below and has a function of suppressing inclination of the valve shaft 41.

The valve shaft holder 6 includes an upper cylindrical small diameter portion 6a, a lower cylindrical large diameter portion 6b, a fitting portion 6c fitted to an inner peripheral surface of a valve body guide portion 72, which will be described later, an annular flange portion 6f, and an extension portion 6k extending downward of the fitting portion 6 c. A housing chamber 6h for housing a valve guide 18 described later is formed inside the valve shaft holder 6. Further, the portion of the valve shaft holder 6 other than the metal flange portion 6f is formed of a resin material.

A female screw 6d is formed downward to a predetermined depth from an upper opening 6g of the cylindrical small diameter portion 6a of the valve shaft holder 6. Therefore, in the present embodiment, the valve shaft holder 6 functions as a female screw member. The screw feeding mechanism a is configured by a male screw 41a formed on the outer periphery of the valve shaft 41 and a female screw 6d formed on the inner periphery of the cylindrical small diameter portion 6a of the valve shaft holder 6.

Further, a pressure equalizing hole 51 is formed through a side surface of the cylindrical large diameter portion 6b of the valve shaft holder 6, and the housing chamber 6h in the cylindrical large diameter portion 6b and the rotor housing chamber 66 (second back pressure chamber) communicate with each other through the pressure equalizing hole 51. By providing the pressure equalizing hole 51 in this manner, the space of the housing 60 that houses the rotor 4 and the space inside the valve shaft holder 6 communicate with each other, and the movement operation of the valve body 17 can be performed smoothly.

A cylindrical valve guide 18 is disposed below the valve shaft 41 so as to be slidable with respect to the housing chamber 6h of the valve shaft holder 6. Further, the valve guide 18 accommodates the compressed valve spring 27 and the spring seat 35. The upper end of the spring seat 35 contacts the protrusion 41c of the valve shaft 41.

The top 21 side of the valve guide 18 is bent substantially at a right angle by press forming. The top portion 21 is formed with a through hole 18 a. Further, a collar 41b is formed below the valve shaft 41.

Here, the valve shaft 41 is inserted into the through hole 18a of the valve guide 18 in a loosely fitted state so as to be rotatable and displaceable in the radial direction with respect to the valve guide 18, and the collar portion 41b is disposed in the valve guide 18 so as to be rotatable and displaceable in the radial direction with respect to the valve guide 18. The valve shaft 41 is inserted through the through hole 18a, and the upper surface of the collar portion 41b is disposed to face the top portion 21 of the valve guide 18. The valve shaft 41 is prevented from coming off by making the diameter of the collar portion 41b larger than the diameter of the through hole 18a of the valve guide 18.

Since the valve shaft 41 and the valve guide 18 are movable in the radial direction relative to each other, the arrangement positions of the valve shaft holder 6 and the valve shaft 41 do not require a relatively high concentric mounting accuracy, and the concentricity with the valve guide 18 and the valve body 17 can be obtained.

A washer 70 having a through hole formed in the center thereof is provided between the top portion 21 of the valve guide 18 and the flange portion 41b of the valve shaft 41.

Further, a valve body 17 and a valve body guide portion 72 that guides movement of the valve body 17 in the direction of the central axis M are disposed inside the valve body 30, and a seal member 48 is interposed between the valve body 17 and the valve body guide portion 72.

The valve body 17 is formed of a metal such as stainless steel, and has a tuning fork-like cross-sectional shape. The valve body 17 includes a substantially cylindrical head portion 17a fixed to the valve guide 18 via an annular fixing member 36, a cylindrical sliding cylinder portion 17b as a portion sliding with respect to the seal member 48, in which a columnar space 17d is formed, and a connecting portion 17c integrally connecting the head portion 17a and the sliding cylinder portion 17 b. Further, a vertical hole 17k and a horizontal through hole 17l are formed as uniform pressure in the head 17 a. Therefore, the pressure in the valve port 16a (in the second pipe joint 15) is guided to the back pressure chamber 28 through the space 17d, the hole portion 17k, and the communication hole 17 l.

The valve body guide portion 72 is a cylindrical body having an inner portion penetrating therethrough, and includes a cylindrical side wall 72a extending in the direction of the central axis M, a flange 72b for fixing the seal member 48, and a holding portion 72c for holding the seal member 48. The flange 72b is disposed below the side wall 72a (on the valve port 16a side) so as to protrude inward in the radial direction, and functions as an engagement portion that engages with the upper surface of the seal member 48. The holding portion 72c is disposed below the seal member 48 (on the valve port 16a side) on the inner periphery of the side wall 72 a. In the valve body guide portion 72, the movement of the valve body 17 in the direction of the center axis M is guided by the seal member 48.

The side wall 72a extends in the direction of the central axis M in the valve main body 30, and accommodates a part of the upper side (rotor 4 side) of the valve body 17 on the inner diameter side. The side wall 72a has a flange portion 72j positioned at an upper end (rotor 4 side), an intermediate cylindrical portion 72k below the flange portion 72j, and a lower end portion 72l below the intermediate cylindrical portion 72k, and is formed by, for example, cutting.

The valve body guide portion 72 is disposed at a predetermined position in the valve body 30 by disposing a flange portion 72j between the flange portion 6f of the valve shaft holder 6 and the lower end portion of the housing 60 and the upper end portion of the valve body 30. Here, the flange portion 72j of the valve body guide portion 72 and the lower end portion of the housing 60, and the flange portion 72j of the valve body guide portion 72 and the upper end portion of the valve main body 30 are integrally formed in a hermetically sealed state over the entire circumference by fixing methods such as welding, brazing, and bonding. The members constituting the valve body guide portion 72 are each formed of a metal such as stainless steel, for example.

Here, the flange portion 72j also functions as a receiving portion of the valve shaft holder 6. That is, the fitting portion 6c of the valve shaft holder 6 is fitted inside the flange portion 72j, and the valve shaft holder 6 is held at a predetermined position and angle by the frictional force between the inner peripheral surface of the flange portion 72j and the outer peripheral surface of the fitting portion 6 c.

As shown in fig. 2, a convex portion 72M that protrudes radially inward and has a partially reduced inner diameter in the direction of the central axis M is formed above the intermediate cylinder portion 72k (on the rotor 4 side). By projecting the convex portion 72m inward in this way, the radial position of the biasing spring 32 described later is regulated, and the position can be prevented from shifting in the radial direction, thereby improving controllability of the motor-operated valve 2. Further, since the radial position of the biasing spring 32 is partially restricted by the convex portion 72m over the entire length, the biasing spring 32 can be prevented from sliding excessively along the inner peripheral surface of the valve body guide portion, as compared with the case where the radial position is restricted over the entire length. Therefore, the controllability of the motor-operated valve 2 is further improved.

As shown in fig. 3a, a step 72x is provided on the inner peripheral surface of the valve body guide portion 72 below the side wall 72a (on the side of the valve port 16 a), and the step 72x is formed by increasing the inner diameter as compared with the portion above the side wall 72 a.

An upper outer peripheral surface 73a on the upper side, a guide flange 73f provided below the upper outer peripheral surface 73a so as to project outward in the radial direction, and a lower outer peripheral surface 73b provided on the lower side so as to have a greatly reduced outer diameter are formed on the outer periphery of the holding portion 72 c. An upper inner peripheral surface 74a on the upper side and a lower inner peripheral surface 74b provided on the lower side with a reduced inner diameter are formed on the inner periphery of the holding portion 72 c. An extension portion 75 is provided below the holding portion 72c, and the extension portion 75 extends downward with an outer diameter of the outer peripheral surface smaller than a diameter of a portion inserted into the side wall 72 a. A lower outer peripheral surface 73b is formed on the outer periphery of the extension portion 75, and a lower outer peripheral surface 73b is formed on the inner periphery.

By providing the extension portion 75 and making the outer diameter of the lower outer peripheral surface 73b smaller than the outer diameter of the upper outer peripheral surface 73a in this way, the fluid flowing into the valve chamber 11 from the first pipe joint 12 can be guided to the valve port 16a without reducing the flow rate of the fluid. Here, if the outer diameter of the lower outer peripheral surface 73b is the same as the outer diameter of the upper outer peripheral surface 73a, the fluid flowing into the valve chamber 11 from the first pipe joint 12 may hit the holding portion 72c and cause a decrease in the flow rate. On the other hand, in the case where the extension portion 75 is not present, the fluid flowing in from the first pipe joint 12 directly hits the valve body 17, and the amplitude of the radial oscillation of the valve body 17 may increase.

Here, the seal member 48 is disposed on the valve body guide portion 72 so as to be sandwiched between the flange 72b and the holding portion 72c in the center axis M direction. Therefore, the amount of collapse of the seal member 48 in the direction of the center axis M can be made constant. The flange 72b has an outer peripheral side of an upper surface thereof abutting the step 72x and abutting the side wall 72a of the spool guide 72. In the holding portion 72c, a step 73z (an upper surface of the guide flange 73 f) formed on an outer peripheral surface of the holding portion 72c is fixed in contact with a lower end 72z of the side wall 72a of the spool guide portion 72. This enables the holding portion 72c to be accurately attached to the predetermined position of the spool guide portion 72.

In addition, when the motor-operated valve 2 is assembled, as shown in fig. 3 (b), the seal member 48 is sandwiched between the flange 72b and the holding portion 72c that abut against the step 72x below the side wall 72 a. Next, the holding portion 72c is moved upward, and the guide flange 73f is brought into contact with the lower end 72z of the side wall 72a and stopped, thereby positioning the holding portion 72 c. Here, the seal member 48 is crushed in the direction of the central axis M by a movement amount (T) by which the holding portion 72c moves upward. In this state, the guide flange 73f of the holding portion 72c is welded to the lower end 72z of the side wall 72 a. Thereby, the holding portion 72c is fixed to the side wall 72 a. The fixing method may be performed by press-fitting the upper outer peripheral surface 73a into the side wall 72a, or welding may be simultaneously employed in addition to such press-fitting.

The inner diameter of the lower inner peripheral surface 74b of the holding portion 72c is formed smaller than the inner diameter of the upper inner peripheral surface 74a on the upper end side. The lower inner peripheral surface 74b of the holding portion 72c is disposed close to the outer peripheral surface (hereinafter referred to as a "sliding surface") of the sliding tube portion 17b, which is a portion where the seal member 48 slides with respect to the valve body 17, with a slight gap therebetween, and regulates the radial position below the valve body 17 (on the side of the valve port 16 a). Therefore, the amplitude of the radial oscillation of the valve body 17 is suppressed so as not to increase. This can reduce leakage when, for example, the valve body 17 is seated on the seat portion 16.

The seal member 48 is formed annularly so as to sandwich the reinforcing plate 48b between two L-shaped annular gaskets 48a having L-shaped cross sections arranged in the direction of the center axis M, and is in sliding contact with the outer peripheral surface of the valve body 17. Here, the L-shaped annular packing 48a includes a lip portion 48j extending from the valve body 17 side to the upper side (rotor 4 side) or the lower side (valve port 16a side) in the direction of the center axis M and slidably contacting the outer peripheral surface of the valve body 17. This allows the inner peripheral surface of the lip portion 48j of the L-shaped annular packing 48a to be in close contact with the outer peripheral surface of the valve body 17, and the back pressure chamber 28 and the valve chamber 11 to be separated from each other in an airtight manner. An annular plate spring 48c that biases the lip portion 48j of the L-shaped annular packing 48a toward the valve body 17 is disposed above the L-shaped annular packing 48a disposed above and below the L-shaped annular packing 48a disposed below. The seal member 48 is a composite seal member formed by joining a plurality of different annular members such as an L-shaped annular packing 48a (seal portion) and a plate spring 48c (biasing portion). The sealing member 48 can maintain airtightness for a long time by urging the lip portion 48j of the L-shaped annular packing 48a toward the valve body 17 by the plate spring 48c, and thereby can suppress a reduction in the operability of the motor-operated valve 2.

The L-shaped annular spacer 48a is made of a fluorine resin material such as PTFE (polytetrafluoroethylene) or PFA (tetrafluoroethylene or perfluoroalkyl vinyl ether copolymer). The reinforcing plate 48b is made of a resin material such as PPS (polyphenylene sulfide) or a metal material such as brass or brass, and the plate spring 48c is made of a metal material such as stainless steel.

As shown in fig. 2, an inner flange 72u protruding radially inward is formed on the inner periphery of the upper side (rotor side) of the side wall 72a of the valve body guide portion 72. As shown in fig. 1, a spring seat metal fitting 29, which is a circular truncated cone-shaped cylindrical body, is disposed on the outer periphery of the connecting portion 17c of the valve body 17 that is movable in the direction of the center axis M. The spring seat metal fitting 29 has a valve flange 29a as an annular flat surface extending to the outer diameter side at the lower end portion. A compressed biasing spring 32 is disposed between the valve flange 29a and an inner flange 72u of the valve body guide portion 72. Here, the inner diameter of the biasing spring 32 is formed larger than the diameter of the sliding surface of the valve body 17, and the head portion 17a and the connecting portion 17c of the valve body 17 are housed on the inner diameter side of the biasing spring 32.

By housing a part of the valve element 17 inside the biasing spring 32 having a large inner diameter in this way, the length of the entire motor-operated valve 2 in the direction of the central axis M can be shortened. Further, since the valve body 17 is biased by the biasing spring 32 having a large inner diameter, the axis of the valve body 17 can be suppressed from being inclined with respect to the central axis M.

Further, since the valve body 17 is pushed down by the biasing spring 32, the contact surface between the thread ridges of the male screw 41a and the female screw 6d can be kept constant. Therefore, when the operating direction of the valve body 17 is switched, the thread rattling does not occur, and the hysteresis phenomenon in the flow rate characteristic can be prevented when the operating direction of the valve body 17 is switched.

The upper end of the biasing spring 32 is disposed on the inner flange 72u of the valve body guide 72, thereby constituting a fixed end that is not relatively movable in the direction of the center axis M with respect to the valve body 30. This maintains the radial position of the biasing spring 32 so that the shaft of the biasing spring 32 does not tilt with respect to the central axis M. The lower end of the biasing spring 32 is disposed on the valve flange 29a, thereby constituting a movable end that can move in accordance with the movement of the valve body 17 in the direction of the center axis M. Thus, when the valve body 17 moves in the direction of the center axis M, the outer periphery of the biasing spring 32 can be prevented from contacting the valve body guide portion 72 and causing excessive sliding resistance.

A convex portion 72M having a diameter that is partially reduced in the direction of the central axis M is formed on the side of the side wall 72a that is fixed to the biasing spring 32. The convex portion 72m guides the outer diameter side of the biasing spring 32 on the fixed end side, and is therefore particularly suitable for a case where the diameter of the biasing spring 32 is large. On the other hand, a wall portion 29b is formed on the movable end side of the side wall 72a closer to the biasing spring 32 (the end portion side of the biasing spring 32 that can move in accordance with the movement of the valve body 17 in the direction of the central axis M), and the wall portion 29b is supported by the valve flange 29a and is formed upright upward (toward the rotor 4) on the inner diameter side of the valve flange 29 a. The wall portion 29b extends in the direction of the center axis M on the inner diameter side of the biasing spring 32, and guides the inner diameter of the biasing spring 32 on the movable end side.

According to the motor-operated valve 2 of this embodiment, the guide flange 73f is brought into contact with the lower end 72z of the side wall 72a of the valve body guide portion 72 to fix the holding portion 72c to the side wall 72a, whereby the sealing member 48 can be accurately attached to a predetermined position of the valve body guide portion 72, and the sealing performance of the sealing member 48 can be improved.

The crushing amount of the seal member 48 can be determined according to the member sizes of the side wall 72a and the holding portion 72 c. Therefore, the amount of collapse of the seal member 48 can be stabilized, and the sealing performance of the seal member 48 can be improved.

In addition, at the time of assembly, it is not necessary to manage the insertion amount of the holding portion 72c depending on the load and the position, and the assemblability of the motor-operated valve 2 is improved. Further, since the side wall 72a has both the function of disposing the seal member 48 and the function of the spring seat, the number of components can be reduced.

Further, by sandwiching the seal member 48 between the flange 72b and the holding portion 72c in the center axis M direction, the seal member 48 can be easily assembled to the valve body guide portion 72. As a comparative example, for example, a motor-operated valve having the following structure is known: a groove is formed in the inner peripheral surface of the valve body guide portion 72 by cutting or the like, and an O-ring is separately disposed.

When the sealing member 48 of the present embodiment is applied to such a conventional motor-operated valve, there may be a difference in hardness between the material of the plate spring 48c and the material of the L-shaped annular packing 48 a. In this case, in the conventional motor-operated valve, the relatively hard leaf spring 48c cannot be assembled in the groove, but in the case where the sealing member 48 is sandwiched between the flange 72b and the holding portion 72c as in the motor-operated valve 2 of the present embodiment, the sealing member 48 can be assembled in the valve body guide portion 72 even when the hardness of the material is different.

In the above-described embodiment, the flange 72b of the valve body guide portion 72 is assembled as a separate member from the side wall 72a, but as shown in fig. 4, a flange portion 72 β having a function as an engaging portion that engages with the upper surface of the seal member 48 may be provided integrally with the side wall 72 a. In this case, too, the sealing member 48 can be accurately attached to the valve body guide portion 72 at a predetermined position, and the sealing performance of the sealing member 48 can be improved.

The inner flange 72u may not be provided in the spool guide 72. In this case, as shown in fig. 4, the compressed biasing spring 32 is disposed between the valve flange 29a and the fitting portion 6c of the valve shaft holder 6. In this case, the biasing spring 32 is inserted from above and is restrained by the valve shaft holder 6, thereby improving the assembling performance of the motor-operated valve 2.

In the above-described embodiment, the case where the guide flange 73f is formed has been described as an example of a method of disposing the holding portion 72c on the side wall 72a of the spool guide portion 72, but the holding portion 72c may be disposed on the side wall 72a without using the guide flange 73 f. For example, as shown in fig. 5, a step 72y may be formed below the inner peripheral surface of the side wall 72a to increase the diameter of the inner peripheral surface.

Further, an annular fixing member 82 may be disposed below the seal member 48, and a spring 84 may be disposed below the fixing member 82, so that the seal member 48, the fixing member 82, and the spring 84 may be sandwiched between the flange portion 72 β and the holding portion 72 c.

In this case, when the motor-operated valve 2 is assembled, the upper surface of the sealing member 48 is brought into contact with the flange portion 72 β, and the sealing member 48, the fixing member 82, and the spring 84 are attached to the side wall 72 a. Next, the holding portion 72c is moved upward, and the upper end surface 72 c' of the holding portion 72c is abutted against the step 72y to position the holding portion 72c, whereby the seal member 48 is sandwiched between the flange portion 72 β and the holding portion 72 c. In this case, the seal member 48 maintains the amount of crush in the direction of the central axis M constant by the holding portion 72c moving upward and the elasticity of the spring 84.

Further, the holding portion 72c may be fixed by caulking. That is, as shown in fig. 5, the lower end of the side wall 72a may be bent inward to form a claw portion 78, and the outer diameter lower end of the holding portion 72c may be caulked by the claw portion 78 to fix the holding portion 72c to the side wall 72a of the valve body guide portion 72. Before the claw portion 78 is formed, the holding portion 72c may be fixed to the side wall 72a by press-fitting, welding, or the like.

In the above-described embodiment, as shown in fig. 6, the outer peripheral surface of the sliding cylinder portion 17b of the valve body 17 may be projected to the outer diameter side. In this case, too, the gap between the outer peripheral surface of the sliding cylinder portion 17b and the inner peripheral surface of the holding portion 72c can be reduced to restrict the radial position of the valve body 17, thereby suppressing the amplitude of the radial oscillation of the valve body 17 from increasing. Further, the inner peripheral surface of the holding portion 72c may be protruded toward the inner diameter side to narrow the gap between the outer peripheral surface of the sliding tube portion 17b and the inner peripheral surface of the holding portion 72 c.

In the above-described embodiment, at least a part of the valve body 17 may be accommodated on the inner diameter side of the biasing spring 32. Therefore, for example, the upper half of the sliding cylinder portion 17b of the valve body 17 may be housed in addition to the head portion 17a and the connecting portion 17 c.

In the above-described embodiment, the spring receiving metal fitting 29 fixed to the valve body 17 is exemplified as a member that supports the biasing spring 32 downward. The spring receiving metal fitting 29 is a member separate from the valve body 17, but a flange supporting the urging spring 32 may be formed integrally with the valve body 17.

Further, in the above-described embodiment, the case where the biasing spring 32 biases in the seating direction in which the valve body 17 is seated on the valve seat portion 16 is exemplified, but the biasing spring 32 may bias in the direction in which the valve body 17 is raised.

As shown in fig. 7, the sealing member 48 of the above-described embodiment may be a sealing member 48 formed by combining an O-ring 48d made of NBR (nitrile rubber), H-NBR (hydrogenated nitrile rubber), or the like and an annular member 48f made of a fluorine-based resin material such as PTFE and having a C-shaped cross section. The seal member 48 is also a composite type seal member in which a plurality of different annular members are joined by combining an annular member 48f as a seal portion and an O-ring 48d as an urging portion. The annular member 48f as a seal portion hermetically separates the back pressure chamber 28 and the valve chamber 11 from each other between the valve body 17 and the back pressure chamber. The O-ring 48d serving as the biasing portion biases the annular member 48f toward the valve body 17. Further, the O-ring 48d is assembled between the flange 72b and the holding portion 72c in a state of being crushed radially inward. Therefore, the outer peripheral surface of the O-ring 48d is in close contact with the inner peripheral surface of the side wall 72a, and the back pressure chamber 28 is separated from the valve chamber 11 in an airtight manner between the side wall 72a and the outer peripheral surface. Therefore, the airtightness can be maintained for a long time, and the deterioration in the operability of the motor-operated valve 2 can be suppressed.

In the embodiment shown in fig. 7, since the seal member 48 is sandwiched between the flange 72b and the holding portion 72c, the seal member 48 can be easily assembled to the valve body guide portion 72 even if the seal member 48 includes the annular member 48f made of PTFE harder than the O-ring 48 d.

In the above-described embodiment, the lower outer peripheral surface 73b is parallel to the central axis M, but the lower outer peripheral surface 73b may be a tapered surface having a diameter that increases in either the vertical direction.

In the above-described embodiment, the example is given in which the seal member 48 includes the L-shaped annular packing 48a, but the seal member may be a lip seal member having a lip portion that slides with respect to the valve body 17 instead of having an L-shaped cross section.

Further, in the above-described embodiment, the upper surface of the seal member 48 is brought into contact with the flange 72b and the flange portion 72 β, but the upper surface of the seal member 48 may be brought into direct contact with the step 72x formed on the inner peripheral surface of the side wall 72 a. In this case, the step 72x functions as an engaging portion that engages with the upper surface of the seal member 48.

In the above-described embodiment, the case where the biasing spring 32 biases the valve body 17 in the valve closing direction has been described as an example, but the biasing spring 32 may bias the valve body 17 in the valve opening direction. For example, one end of the biasing spring is disposed on the lower surface of the flange on which the valve element is suspended, and the other end of the biasing spring is disposed on the upper surface of the flange that protrudes toward the inner diameter side of the valve element holding portion. Thereby, the upper side (rotor 4 side) of the motor-operated valve 2 becomes the movable end side, and the lower side (valve port 16a side) becomes the fixed end side.

In a refrigeration cycle including, for example, a compressor, a condenser, an expansion valve, an evaporator, and the like, the motor-operated valve 2 of the above-described embodiment is used as an expansion valve provided between the condenser and the evaporator and a flow rate control valve of each flow path.

Claims

1. An electrically operated valve in which a rotary motion of a rotor housed in a housing is converted into a linear motion by a screw engagement between a male screw member and a female screw member, a valve body housed in a valve body is moved in a central axis direction of the valve body based on the linear motion, a back pressure chamber is provided above the valve body, and a pressure in the valve port is introduced into the back pressure chamber,

the electrically operated valve is characterized by comprising:

the holding portion is fixed to the side wall in the center axis direction in an abutting manner by a step formed on at least one of an inner peripheral surface of the side wall and an outer peripheral surface of the holding portion,

the holding portion includes an extension portion that extends toward the valve port side so that an outer diameter of an outer peripheral surface of the extension portion is smaller than a diameter of a portion inserted into the side wall, and faces an opening of a joint fixed to a side surface of the valve main body.

2. Electrically operated valve according to claim 1,

3. Electrically operated valve according to claim 1,

4. An electrically operated valve according to any one of claims 1 to 3,

5. Electrically operated valve according to claim 1,

the valve body further includes an urging spring for urging the valve element.

6. Electrically operated valve according to claim 5,

7. Electrically operated valve according to claim 6,

at least a part of the valve body is housed inside the biasing spring.

8. Electrically operated valve according to claim 5,

an inner flange protruding radially inward is formed on the rotor side fixed to the side wall of the valve body,

a valve flange protruding outward in an outer diameter direction is disposed on the valve body, the valve body moving in the central axis direction,

the urging spring is disposed between the inner flange and the valve flange.

9. Electrically operated valve according to claim 5,

10. Electrically operated valve according to claim 1,

11. A refrigeration cycle system comprises a compressor, a condenser, an expansion valve and an evaporator, and is characterized in that,

use of an electrically operated valve as claimed in any one of claims 1 to 10.