JP6864652B2 - Electric valve and refrigeration cycle system - Google Patents

Description

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

Conventionally, fluid control valves used in large packaged air conditioners and refrigerators have been known. In this fluid control valve, good operability is achieved even when a large diameter and a high pressure difference occur due to the rationalization of control equipment such as combining multiple electric valves used for flow control into one. Performance that can be demonstrated is desired. However, in the flow control of a relatively large diameter, the load on the valve body generated by the pressure difference is large with respect to the thrust of the screw generated by the torque of the magnet, and a large driving force is required to operate the valve body.

Therefore, in order to improve the operability of the valve body, a pressure balance mechanism as described below is adopted (see, for example, Patent Document 1). Specifically, as in the electric valve 101 shown in FIG. 8, the back pressure chamber 129 is defined on the upper side of the valve chamber 107, and the pressure in the valve port 119 is applied to the conduction path 124 provided in the valve body 120. By introducing the pressure into the back pressure chamber 129 and using the pressure (back pressure) in the back pressure chamber 129, the pushing down force acting on the valve body 120 in the valve closed state (force acting in the valve closing direction). The force due to the pressure difference between the force and the pushing force (the force acting in the valve opening direction) is canceled, and the load on the valve body 120 is reduced.

In the electric valve 101 that employs this pressure balance mechanism, a seal member 137 is interposed between the valve body 120 and the valve body guide portion 172 in order to airtightly separate the back pressure chamber 129 and the valve chamber 107. There is. Here, in the above-mentioned electric valve 101, the seal member 137 is mounted on the valve body 120 side and adopts an outer seal structure that abuts on the inner peripheral surface of the valve body guide portion 172, but the seal member 137 is arranged. It is not always necessary to adopt the outer seal structure. For example, it is conceivable to adopt an inner seal structure in which the seal member 137 is mounted on the valve body guide portion 172 side and comes into contact with the outer peripheral surface of the valve body 120.

Japanese Unexamined Patent Publication No. 2017-180639

However, when the inner seal structure is adopted, there is a problem that the number of parts constituting the electric valve is larger and the assembling property is complicated as compared with the case where the outer seal structure is adopted.
Further, it is an issue to make it possible to accurately attach the seal member to the valve body guide portion so as not to affect the seal performance such as leakage or increase in sliding resistance.

An object of the present invention is to provide an electric valve having a good assembly property by accurately mounting a seal member on a valve body guide portion and improving the sealability of the seal member, and a refrigeration cycle system using the electric valve. is there.

[1] The electric valve of the present invention is
The rotary motion of the rotor housed inside the case is converted into a linear motion by screwing the male screw member and the female screw member, and the valve body housed in the valve body is converted into a linear motion based on this linear motion. An electric valve that moves in the direction of the central axis of the main body and has a back pressure chamber on the upper side of the valve body to introduce the pressure in the valve port into the back pressure chamber.
A side wall extending in the central axis direction in the valve body and accommodating a part of the valve body on the rotor side on the inner diameter side.
A composite type sealing member which is mounted on the inner circumference of the side wall on the valve port side and which is a composite of a sealing portion and an urging portion for urging the sealing portion.
The side wall is provided with a holding portion which is arranged on the valve port side of the seal member and holds the seal member.
An engaging portion that engages with the upper surface of the sealing member is provided on the valve port side of the side wall, and the sealing member is arranged between the engaging portion and the holding portion in the central axial direction. ,
It is characterized in that the holding portion is abutted in the central axial direction and fixed to the side wall by utilizing a step formed on at least one of the inner peripheral surface of the side wall and the outer peripheral surface of the holding portion.

In this way, by utilizing the step and abutting the holding portion in the direction of the central axis and fixing it to the side wall, the seal member can be mounted at an accurate position on the side wall, and the sealability of the seal member can be improved. Further, since it is not necessary to control the insertion amount of the holding portion by the load and the position at the time of assembly, the assembling property of the electric valve can be maintained even when the seal member is mounted on the inner circumference of the side wall.

[2] Further, the electric valve of the present invention is
A guide flange protruding toward the outer diameter is formed on the holding portion.
The step formed on the outer peripheral surface by the guide flange is abutted against the lower end portion of the side wall, and the holding portion is fixed to the side wall.
In this way, by abutting the step formed on the guide flange against the lower end of the side wall and fixing the holding portion to the side wall, the holding portion can be accurately mounted at a predetermined position of the valve body guide portion.

[3] Further, the electric valve of the present invention is
The upper end surface of the holding portion is abutted against the step formed on the inner peripheral surface of the side wall, and the holding portion is fixed to the side wall.
In this way, even when the holding portion is abutted against the step formed on the inner peripheral surface of the side wall and the holding portion is fixed to the side wall, the holding portion is accurately mounted at a predetermined position of the valve body guide portion. Can be done.

[4] Further, the electric valve of the present invention is
The holding portion is characterized in that the position of the valve body on the valve port side in the radial direction is restricted.
As a result, the amplitude of the radial swing of the valve body is suppressed so as not to increase. Therefore, for example, it is possible to reduce valve leakage when the valve body is seated on the valve seat portion.

[5] Further, the electric valve of the present invention is
The holding portion is characterized by including an extending portion extending to the valve port side with an outer diameter of the outer peripheral surface smaller than that of a portion inserted into the side wall.
In this way, by providing the extension portion with the outer diameter of the outer peripheral surface reduced, it is possible to guide the fluid to the valve port without reducing the flow rate of the fluid flowing into the valve chamber from the pipe joint.

[6] Further, the electric valve of the present invention is
It is characterized by further including an urging spring for urging the valve body.
In this way, by providing the urging spring that urges the valve body, the contact surface between the male and female threads can be kept constant.

[7] Further, the electric valve of the present invention is
The urging spring is characterized in that the inner diameter is formed to be larger than the diameter of the sliding surface of the valve body, and the valve body is urged in the valve body in the central axial direction.
In this way, since the valve body is urged by the urging spring having a large inner diameter, it is possible to prevent the axis of the valve body from tilting with respect to the central axis.

[8] Further, the electric valve of the present invention is
The inside of the urging spring is characterized in that at least a part of the valve body is housed.
As a result, the length of the entire electric valve in the central axis direction can be shortened.

[9] Further, the electric valve of the present invention is
An inner flange protruding toward the inner diameter is formed on the rotor side of the side wall.
A valve flange projecting to the outer diameter side is arranged on the valve body.
The urging spring is characterized in that it is arranged between the inner flange and the valve flange.

By arranging the upper end of the urging spring on the inner flange of the side wall in this way, it is possible to maintain the radial position of the urging spring so that the axis of the urging spring does not tilt with respect to the central axis. it can. Further, since the lower end of the urging spring is arranged on the valve flange protruding toward the outer diameter side of the valve body, the outer circumference of the urging spring comes into contact with the valve body guide portion and excessive sliding resistance is applied to the urging spring. Can be suppressed from occurring.

[10] Further, the electric valve of the present invention is
On the fixed end side of the urging spring, a convex portion is formed that projects toward the inner diameter side of the side wall and locally reduces the inner diameter of the side wall in the central axis direction.
A wall portion extending in the central axis direction is formed on the movable end side of the urging spring on the inner diameter side of the urging spring.

In this way, by forming a convex portion protruding toward the inner diameter side of the side wall on the fixed end side of the urging spring, the outer diameter side of the urging spring is guided on the fixed end side, so that the diameter of the urging spring is increased. Suitable for large cases. Further, by forming the wall portion on the inner diameter side of the movable end of the urging spring, the inner diameter side of the urging spring is guided on the movable end side.

Further, by projecting the convex portion toward the inner diameter side, the radial position of the urging spring is regulated, and the position can be prevented from being displaced in the radial direction, so that the controllability of the electric valve is improved. Further, since the radial position is regulated by the convex portion only a part of the total length of the urging spring, the valve body guide portion of the urging spring is regulated as compared with the case where the radial position is regulated over the entire length. Excessive sliding on the inner peripheral surface of the spring is suppressed.

[11] Further, the electric valve of the present invention is
The seal member is characterized in that it is formed by using a lip seal having a lip portion that slides on the valve body.
As described above, by using the seal member using the lip seal, the crushed amount of the seal member can be determined by the component dimensions of the side wall and the holding portion, so that the crushed amount of the seal member can be stabilized.

[12] Further, the refrigeration cycle system of the present invention is
A refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, characterized by using the above-mentioned electric valve.
Such an electric valve is suitable as a refrigeration cycle system because it can reliably adjust the opening degree of the valve and control the flow rate as a control valve.

According to the present invention, it is possible to provide an electric valve having a good assembly property in which a seal member is accurately mounted on a valve body guide portion and the sealability of the seal member is improved, and a refrigeration cycle system using the electric valve. it can.

It is the schematic sectional drawing of the electric valve which concerns on embodiment. It is an enlarged view of the part above the valve body guide part in the electric valve which concerns on embodiment. It is an enlarged view of the vicinity of the seal member in the electric valve which concerns on embodiment. It is an enlarged view of the valve body guide part in the electric valve which concerns on other embodiment. It is an enlarged view of the holding part in the electric valve which concerns on other embodiment. It is an enlarged view of the valve body in the electric valve which concerns on other embodiment. It is an enlarged view of the seal member in the electric valve which concerns on other embodiment. It is the schematic sectional drawing which shows the seal part of the conventional electric valve.

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

In the electric valve 2, the valve body 30 is integrally connected to the lower side of the opening side of the case 60 having a tubular cup shape made of metal by welding or the like.
Here, the valve body 30 is made of a metal such as stainless steel, and has a valve chamber 11 which is a space formed inside the valve body 17 on the outside. Further, a first pipe joint 12 made of stainless steel or copper, for example, which directly communicates with the valve chamber 11, is fixedly mounted on the side surface of the valve body 30. Further, a valve seat portion 16 formed by penetrating the inside of the valve port 16a having a circular cross section is incorporated in the lower inner side of the valve body 30. The valve port 16a is provided directly below the valve body 17 in the coaxial direction 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 fixedly mounted on the valve seat portion 16.

A rotatable rotor 4 is housed in the inner circumference of the case 60, and a valve shaft 41 is arranged at a shaft core portion of the rotor 4 via a bush member 33. The rotor 4 is made of a magnetic material such as a resin material containing magnetic powder. Both the bush member 33 and the valve shaft 41 are made of a metal such as stainless steel, and the valve shaft 41 and the rotor 4 connected by the bush member 33 move integrally in the vertical direction while rotating. A male screw 41a is formed on the outer peripheral surface of the valve shaft 41 near the middle portion. In this embodiment, the valve shaft 41 functions as a male screw member. Further, the valve body 17 can be brought close to or separated from the valve port 16a.

A stator composed of a yoke, a bobbin, a coil, and the like (not shown) is arranged on the outer periphery of the case 60, and a stepping motor is configured by the rotor 4 and the stator.
A guide support 52 is fixed to the ceiling surface of the case 60. The guide support 52 has a cylindrical portion 53 and an umbrella-shaped portion 54 formed on the upper end side of the cylindrical portion 53, and the entire guide support 52 is integrally formed by press working. The umbrella-shaped portion 54 is formed in substantially the same shape as the inside of the top of the case 60.

A tubular member 65 that also serves as a guide for the valve shaft 41 is fitted in the cylindrical portion 53 of the guide support 52. The tubular member 65 is made of metal, synthetic resin, or a surface-treated component, and holds the valve shaft 41 rotatably.

Below the bush member 33 of the valve shaft 41, a valve shaft holder 6 having a function of forming a screw feed mechanism A with the valve shaft 41 and suppressing the inclination of the valve shaft 41 is provided as a valve body. It is fixed so that it cannot rotate relative to 30.

The valve shaft holder 6 has a tubular small diameter portion 6a on the upper side, a tubular large diameter portion 6b on the lower side, a fitting portion 6c fitted to the inner peripheral surface of the valve body guide portion 72 described later, and a ring shape. It is composed of a flange portion 6f and an extension portion 6k extending below the fitting portion 6c. A storage chamber 6h for accommodating the valve guide 18, which will be described later, is formed inside the valve shaft holder 6. The valve shaft holder 6 is made of a resin material except for the metal flange portion 6f.

Further, a female screw 6d is formed downward from the upper opening 6g of the tubular small diameter portion 6a of the valve shaft holder 6 to a predetermined depth. Therefore, in the present embodiment, the valve shaft holder 6 functions as a female screw member. The screw feed mechanism A is composed of a male screw 41a formed on the outer circumference of the valve shaft 41 and a female screw 6d formed on the inner circumference of the tubular small diameter portion 6a of the valve shaft holder 6.

Further, a pressure equalizing hole 51 is formed in the side surface of the tubular large diameter portion 6b of the valve shaft holder 6, and the pressure equalizing hole 51 allows the accommodating chamber 6h in the tubular large diameter portion 6b and the rotor accommodating chamber. It communicates with 66 (second back pressure chamber). By providing the pressure equalizing hole 51 in this way, the space for accommodating the rotor 4 of the case 60 and the space inside the valve shaft holder 6 are communicated with each other, and the valve body 17 can be smoothly moved.

Further, below the valve shaft 41, a tubular valve guide 18 is slidably arranged with respect to the accommodating chamber 6h of the valve shaft holder 6. Further, the compressed valve spring 27 and the spring receiver 35 are housed in the valve guide 18. The upper end of the spring receiver 35 is in contact with the protruding portion 41c of the valve shaft 41.

The ceiling portion 21 side of the valve guide 18 is bent at a substantially right angle by press molding. A through hole 18a is formed in the ceiling portion 21. Further, a flange portion 41b is further 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 loose state so as to be rotatable with respect to the valve guide 18 and displaceable in the radial direction, and the flange portion 41b is a valve. It is arranged in the valve guide 18 so as to be rotatable with respect to the guide 18 and displaceable in the radial direction. Further, the valve shaft 41 is arranged so that the through hole 18a is inserted and the upper surface of the flange portion 41b faces the ceiling portion 21 of the valve guide 18. Since the flange portion 41b has a diameter larger than that of the through hole 18a of the valve guide 18, the valve shaft 41 is prevented from coming off.

Since the valve shaft 41 and the valve guide 18 can be moved in the radial direction to each other, the valve guide 18 and the valve guide 18 and the valve guide 18 and the valve guide 18 are not required to have a high degree of concentric mounting accuracy with respect to the arrangement positions of the valve shaft holder 6 and the valve shaft 41. Concentricity with the valve body 17 can be obtained.

A washer 70 having a through hole formed in the central portion is installed between the ceiling portion 21 of the valve guide 18 and the flange portion 41b of the valve shaft 41.
Further, inside the valve body 30, a valve body 17 and a valve body guide portion 72 for guiding the movement of the valve body 17 in the central axis M direction are arranged between the valve body 17 and the valve body guide portion 72. A seal member 48 is interposed in the body.

The valve body 17 is a component made of a metal such as stainless steel, and has a tuning fork-shaped cross-sectional shape. The valve body 17 is a cylindrical portion that slides on a substantially cylindrical head 17a fixed to the valve guide 18 via an annular fixture 36 and a seal member 48 having a columnar space 17d formed therein. It is composed of a sliding cylinder portion 17b and a connecting portion 17c that integrally connects the head portion 17a and the sliding cylinder portion 17b. Further, inside the head 17a, a hole portion 17k in the vertical direction and a conduction hole 17l in the horizontal direction are formed as pressure equalizing paths. Therefore, the pressure of the valve port 16a (inside the second pipe joint 15) is guided to the back pressure chamber 28 through the space 17d, the hole portion 17k, and the conduction hole 17l.

The valve body guide portion 72 is a cylindrical body penetrating inside, and includes a cylindrical side wall 72a extending in the central axis M direction, a flange 72b for fixing the seal member 48, and a holding portion 72c for holding the seal member 48. .. The flange 72b is arranged so as to project toward the inner diameter side below the side wall 72a (valve port 16a side), and has a function as an engaging portion that engages with the upper surface of the seal member 48. The holding portion 72c is a component arranged below the seal member 48 (on the valve port 16a side) on the inner circumference of the side wall 72a. Further, in the valve body guide portion 72, the valve body 17 is guided to move in the central axis M direction by the seal member 48.

Further, the side wall 72a extends in the central axis M direction in the valve 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 located at the upper end (rotor 4 side), an intermediate cylinder portion 72k below the flange portion 72j, and a lower end portion 72l further below the flange portion 72j. It is formed.

The valve body guide portion 72 is arranged at a predetermined position in the valve body 30 by arranging the flange portion 72j between the flange portion 6f of the valve shaft holder 6 and the lower end portion of the case 60 and the upper end portion of the valve body 30. Is located in. Here, the flange portion 72j of the valve body guide portion 72 and the lower end portion of the case 60, and the flange portion 72j of the valve body guide portion 72 and the upper end portion of the valve body 30 are fixed by welding, brazing, adhesion, or the like. It is integrated in a sealed state over the entire circumference by means. The parts constituting the valve body guide portion 72 are each made of a metal such as stainless steel.

Here, the flange portion 72j also has a function 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 placed at a predetermined position by the frictional force between the inner peripheral surface of the flange portion 72j and the outer peripheral surface of the fitting portion 6c. Held at an angle.

Further, as shown in FIG. 2, a convex portion 72m is formed above the intermediate tubular portion 72k (rotor 4 side) so as to project toward the inner diameter side and locally reduce the inner diameter in the central axis M direction. By projecting the convex portion 72 m toward the inner diameter side in this way, the radial position of the urging spring 32, which will be described later, is restricted, and the radial position can be prevented from shifting, so that the controllability of the electric valve 2 is improved. To do. Further, since the radial position is regulated by the convex portion 72 m only a part of the total length of the urging spring 32, the valve body of the urging spring 32 is regulated in the radial position over the entire length. Excessive sliding of the guide portion on the inner peripheral surface is suppressed. Therefore, the controllability of the electric valve 2 is further improved.

Further, as shown in FIG. 3A, the inner peripheral surface of the valve body guide portion 72 below the side wall 72a (on the valve port 16a side) is formed by making the inner diameter larger than above the side wall 72a. A step 72x is provided.

On the outer periphery of the holding portion 72c, an upper outer peripheral surface 73a on the upper side, a guide flange 73f projecting to the outer diameter side below the upper outer peripheral surface 73a, and a lower outer peripheral surface 73b having a significantly reduced outer diameter are formed on the lower side. ing. Further, on the inner circumference of the holding portion 72c, an upper inner peripheral surface 74a on the upper side and a lower inner peripheral surface 74b having a reduced inner diameter on the lower side are formed. Further, below the holding portion 72c, an extending portion 75 extending downward with the outer diameter of the outer peripheral surface made smaller than the portion inserted into the side wall 72a is provided. A lower outer peripheral surface 73b is formed on the outer circumference of the extended portion 75, and a lower outer peripheral surface 73b is formed on the inner circumference.

In this way, 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, the flow rate of the fluid flowing into the valve chamber 11 from the first pipe joint 12 is reduced. It can be led to the valve port 16a without causing it. Here, if the outer diameter of the lower outer peripheral surface 73b is equal to the outer diameter of the upper outer peripheral surface 73a, the fluid flowing into the valve chamber 11 from the first pipe joint 12 collides with the holding portion 72c, causing a decrease in the flow rate. There is a risk. On the other hand, when the extension portion 75 does not exist, the fluid flowing in from the first pipe joint 12 directly collides with the valve body 17, so that the amplitude of the radial swing of the valve body 17 may increase.

Here, the seal member 48 is sandwiched between the flange 72b and the holding portion 72c in the direction of the central axis M, and is arranged on the valve body guide portion 72. Therefore, the amount of crushing of the seal member 48 in the central axis M direction can be made constant. Further, the flange 72b abuts the outer peripheral side of the upper surface thereof against the step 72x and is in contact with the side wall 72a of the valve body guide portion 72. Further, the holding portion 72c is fixed by abutting a step 73z (upper surface of the guide flange 73f) formed on the outer peripheral surface of the holding portion 72c against the lower end 72z of the side wall 72a of the valve body guide portion 72. As a result, the holding portion 72c can be accurately mounted at a predetermined position of the valve body guide portion 72.

When assembling the electric valve 2, as shown in FIG. 3B, the seal member 48 is sandwiched between the flange 72b and the holding portion 72c that come into contact with the step 72x below the side wall 72a. Next, the holding portion 72c is moved upward to hold the guide flange 73f against the lower end 72z of the side wall 72a, and the holding portion 72c is positioned. Here, the seal member 48 is crushed in the central axis M direction by the amount of movement (T) in which the holding portion 72c is moved upward. In this state, the guide flange 73f of the holding portion 72c is welded to the lower end 72z of the side wall 72a. As a result, the holding portion 72c is fixed to the side wall 72a. The means for fixing may be performed by press-fitting the upper outer peripheral surface 73a into the side wall 72a, and further, welding may be used in combination with such press-fitting.

Further, the inner diameter of the lower inner peripheral surface 74b of the holding portion 72c is formed to be smaller than the inner diameter of the upper end side of the upper inner peripheral surface 74a. The lower inner peripheral surface 74b of the holding portion 72c is minute with respect to the outer peripheral surface (hereinafter, referred to as a sliding surface) of the sliding cylinder portion 17b, which is a portion on which the seal member 48 slides on the valve body 17. It is arranged close to each other with a gap between the two, and regulates the radial position below the valve body 17 (on the valve port 16a side). Therefore, the amplitude of the radial swing of the valve body 17 is suppressed so as not to increase. Thereby, for example, leakage when the valve body 17 is seated on the valve seat portion 16 can be reduced.

The seal member 48 is formed in an annular shape with a reinforcing plate 48b sandwiched between two L-shaped annular packings 48a having an L-shaped cross section arranged in the direction of the central axis M, and is in sliding contact with the outer peripheral surface of the valve body 17. .. Here, the L-shaped annular packing 48a extends from the valve body 17 side to the upper side (rotor 4 side) or the lower side (valve port 16a side) in the central axis M direction, and is a lip portion that is in sliding contact with the outer peripheral surface of the valve body 17. It has 48j. As a result, the inner peripheral surface of the lip portion 48j of the L-shaped annular packing 48a and the outer peripheral surface of the valve body 17 can be brought into close contact with each other, and the back pressure chamber 28 and the valve chamber 11 can be airtightly separated. .. Further, on the upper side of the L-shaped annular packing 48a arranged above and the lower side of the L-shaped annular packing 48a arranged below, the lip portion 48j of the L-shaped annular packing 48a is urged on the valve body 17 side. An annular leaf spring 48c is arranged. As described above, the seal member 48 is a composite type seal member formed by combining a plurality of different annular members such as an L-shaped annular packing 48a (seal portion) and a leaf spring 48c (urging portion). By urging the lip portion 48j of the L-shaped annular packing 48a to the valve body 17 side with the leaf spring 48c, the seal member 48 can bring the inner peripheral surface and the outer peripheral surface of the valve body 17 into close contact with each other for a long period of time. Since the airtightness can be maintained over a period of time, it is possible to suppress a decrease in the operability of the electric valve 2.

The L-shaped cyclic packing 48a is made of a fluororesin material such as PTFE (polytetrafluoroethylene) or PFA (tetrafluoroethylene / 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 leaf spring 48c is made of a metal material such as stainless steel.

Further, as shown in FIG. 2, an inner flange 72u protruding toward the inner diameter side is formed on the inner circumference 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 receiving metal fitting 29, which is a truncated cone-shaped cylinder, is arranged on the outer periphery of the connecting portion 17c of the valve body 17 that can move in the central axis M direction. The spring receiving metal fitting 29 has a valve flange 29a which is an annular flat surface extending to the outer diameter side at the lower end portion. A compressed urging spring 32 is arranged between the valve flange 29a and the inner flange 72u of the valve body guide portion 72. Here, the inner diameter of the urging spring 32 is formed to be larger than the diameter of the sliding surface of the valve body 17, and the head portion 17a of the valve body 17 and the connecting portion 17c are housed on the inner diameter side of the urging spring 32. ..

In this way, by accommodating a part of the valve body 17 inside the urging spring 32 having a large inner diameter, the length of the entire electric valve 2 in the central axis M direction can be shortened. Further, since the valve body 17 is urged by the urging spring 32 having a large inner diameter, it is possible to prevent the axis of the valve body 17 from tilting with respect to the central axis M.

Further, since the valve body 17 is pushed downward by the urging spring 32, the contact surface between the male screw 41a and the female screw 6d can be kept constant. Therefore, screw backlash does not occur when the operating direction of the valve body 17 is switched, and hysteresis can be prevented in the flow rate characteristics when the operating direction of the valve body 17 is switched.

Further, the upper end of the urging spring 32 is arranged on the inner flange 72u of the valve body guide portion 72 to form a fixed end that does not move relatively in the central axis M direction with respect to the valve body 30. As a result, the radial position of the urging spring 32 is maintained so that the axis of the urging spring 32 does not tilt with respect to the central axis M. Further, the lower end of the urging spring 32 is arranged on the valve flange 29a to form a movable end that moves with the movement of the valve body 17 in the central axis M direction. As a result, when the valve body 17 moves in the direction of the central axis M, it is possible to prevent the outer circumference of the urging spring 32 from coming into contact with the valve body guide portion 72 to cause excessive sliding resistance.

Further, on the fixed end side of the urging spring 32 on the side wall 72a, a convex portion 72m having a locally reduced inner diameter is formed in the direction of the central axis M. Since the convex portion 72m guides the outer diameter side of the urging spring 32 on the fixed end side, it is particularly suitable when the diameter of the urging spring 32 is large. On the other hand, the movable end side of the urging spring 32 on the side wall 72a (the end side of the urging spring 32 that moves with the movement of the valve body 17 toward the central axis M) is supported by the valve flange 29a. A wall portion 29b that rises upward (rotor 4 side) is formed on the inner diameter side of the valve flange 29a. The wall portion 29b extends in the central axis M direction on the inner diameter side of the urging spring 32, and guides the inner diameter of the urging spring 32 on the movable end side.

According to the electric valve 2 according to this embodiment, the guide flange 73f is abutted against the lower end 72z of the side wall 72a of the valve body guide portion 72, and the holding portion 72c is fixed to the side wall 72a to fix the holding portion 72c to the side wall 72a. The seal member 48 can be accurately mounted at a predetermined position to improve the sealability of the seal member 48.

Further, the amount of crushing of the seal member 48 can be determined by the component dimensions of the side wall 72a and the holding portion 72c. Therefore, the amount of crushing of the seal member 48 can be stabilized, and the sealability of the seal member 48 can be improved.

Further, since it is not necessary to control the insertion amount of the holding portion 72c by the load and the position at the time of assembling, the assembling property of the electric valve 2 is improved. Further, since the side wall 72a has both the function of arranging the seal member 48 and the function of receiving the spring, the number of parts can be reduced.

Further, by sandwiching the seal member 48 between the flange 72b and the holding portion 72c in the direction of the central axis M, the seal member 48 can be easily assembled to the valve body guide portion 72. As a comparative example, for example, an electric valve having a structure in which a groove is formed on the inner peripheral surface of the valve body guide portion 72 by cutting or the like and an O-ring is arranged independently is known.

Considering that the sealing member 48 of the present embodiment is applied to such a conventional electric valve, there may be a difference in hardness between the material of the leaf spring 48c and the material of the L-shaped annular packing 48a. In such a case, the harder leaf spring 48c cannot be assembled in the groove with this conventional electric valve, but the seal member 48 is between the flange 72b and the holding portion 72c as in the electric valve 2 of the present embodiment. When sandwiching the seal member 48, the seal member 48 can be attached to the valve body guide portion 72 even if there is a difference in hardness between the materials.

In the above-described embodiment, the flange 72b of the valve body guide portion 72 is incorporated as a separate part from the side wall 72a, but as shown in FIG. 4, it is integrally formed with the side wall 72a and is a sealing member. A flange portion 72β that functions as an engaging portion that engages with the upper surface of the 48 may be provided. Even in this case, the seal member 48 can be accurately mounted at a predetermined position of the valve body guide portion 72, and the sealability of the seal member 48 can be improved.

Further, it is not necessary to provide the inner flange 72u on the valve body guide portion 72. In this case, the compressed urging spring 32 is arranged between the valve flange 29a and the fitting portion 6c of the valve shaft holder 6, as shown in FIG. In this case, the urging spring 32 is inserted from above and held down by the valve shaft holder 6, so that the assembling property of the electric valve 2 is improved.

Further, in the above-described embodiment, the case where the guide flange 73f is formed as a means for arranging the holding portion 72c on the side wall 72a of the valve body guide portion 72 is described as an example, but the guide flange 73f is used. Instead, the holding portion 72c may be arranged on the side wall 72a. For example, as shown in FIG. 5, a step 72y having an increased diameter of the inner peripheral surface may be formed below the inner peripheral surface of the side wall 72a.

Further, an annular fixing member 82 is arranged below the seal member 48, and a spring 84 is arranged further below the seal member 48, and the seal member 48, the fixing member 82, and the spring 84 are placed between the flange portion 72β and the holding portion 72c. The shape may be sandwiched.

In this case, when assembling the electric valve 2, the upper surface of the seal member 48 is brought into contact with the flange portion 72β, and the seal member 48, the fixing member 82, and the spring 84 are mounted on the side wall 72a. Next, the holding portion 72c is moved upward, the upper end surface 72c'of the holding portion 72c is abutted against the step 72y to position the holding portion 72c, and the seal member 48 is placed between the flange portion 72β and the holding portion 72c. Insert it. In this case, the seal member 48 is held so that the amount of crushing in the central axis M direction becomes constant by moving the holding portion 72c upward and the elasticity of the spring 84.

The holding portion 72c may be crimped and fixed. That is, as shown in FIG. 5, the lower end of the side wall 72a is bent toward the inner diameter side to form the claw portion 78, and the lower end of the outer diameter of the holding portion 72c is crimped by the claw portion 78 to guide the holding portion 72c to the valve body guide portion 72. It may be fixed to the side wall 72a of the. Before forming the claw portion 78, the holding portion 72c may be fixed to the side wall 72a in advance by press-fitting, welding, press-fitting and welding, or the like.

Further, 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 toward the outer diameter side. Even in this case, 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, the radial position of the valve body 17 is restricted, and the radial position of the valve body 17 is restricted. The amplitude of the shaking is suppressed so that it does not increase. Further, the inner peripheral surface of the holding portion 72c may be projected toward the inner diameter side to reduce the gap between the outer peripheral surface of the sliding cylinder portion 17b and the inner peripheral surface of the holding portion 72c.

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

Further, in the above-described embodiment, the spring receiving metal fitting 29 fixed to the valve body 17 is exemplified as a member for supporting the urging spring 32 below. Although the spring receiving metal fitting 29 is a separate part from the valve body 17, the flange that supports the urging spring 32 below may be integrally formed with the valve body 17.

Further, in the above-described embodiment, the case where the urging spring 32 is urged in the seating direction in which the valve body 17 is seated on the valve seat portion 16 is illustrated, but the urging spring 32 is the valve body. It may be urged in the direction of raising 17.

Further, in the seal member 48 according to the above-described embodiment, as shown in FIG. 7, the seal member 48 includes an O-ring 48d made of NBR (nitrile rubber), H-NBR (hydrogenated nitrile rubber), or the like, and fluorine such as PTFE. A seal member 48 in which an annular member 48f made of a based resin material and having a C-shaped cross section is combined may be adopted. The seal member 48 is also a composite type seal member in which a plurality of different annular members are combined, which is formed 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 sealing portion airtightly separates the back pressure chamber 28 and the valve chamber 11 from the valve body 17. Further, the O-ring 48d as the urging portion urges 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 inward in the radial direction. 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 and the valve chamber 11 are airtightly separated from the side wall 72a. Therefore, the airtightness can be maintained for a long period of time, and the decrease in the operability of the electric valve 2 is suppressed.

Further, also 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 is an annular shape made of PTFE, which is harder than the O-ring 48d. Even if the member 48f is provided, it can be easily assembled to the valve body guide portion 72.

Further, in the above-described embodiment, the case where the lower outer peripheral surface 73b is parallel to the central axis M is illustrated, but the lower outer peripheral surface 73b is a tapered surface whose diameter is increased in either the upper or lower direction. You may.

Further, in the above-described embodiment, the case where the seal member 48 includes the L-shaped annular packing 48a is described as an example, but if it is a lip seal type having a lip portion that slides on the valve body 17. It does not necessarily have to have an L-shaped cross section.

Further, in the above-described embodiment, the upper surface of the seal member 48 is abutted against the flange 72b and the flange portion 72β, but the upper surface of the seal member 48 is directly applied to the step 72x formed on the inner peripheral surface of the side wall 72a. You may touch them. In this case, the step 72x has a function as an engaging portion that engages with the upper surface of the seal member 48.

Further, in the above-described embodiment, the case where the urging spring 32 urges the valve body 17 in the valve closing direction is described as an example, but the urging spring 32 attaches the valve body 17 in the valve opening direction. You may try to force it. For example, one end of the urging spring is arranged on the lower surface of the flange that lifts the valve body, and the other end of the urging spring is arranged on the upper surface of the flange that protrudes toward the inner diameter side of the valve body holding portion. As a result, the upper side (rotor 4 side) of the electric valve 2 is the movable end side, and the lower side (valve port 16a side) is the fixed end side.

Further, the electric valve 2 of the above-described embodiment is, for example, an expansion valve or various types provided between the condenser and the evaporator in a refrigeration cycle system including a compressor, a condenser, an expansion valve, an evaporator and the like. It is used as a flow control valve for the flow path.

2 Electric valve 4 Rotor 6 Valve shaft holder 6a Cylindrical small diameter part 6b Cylindrical large diameter part 6c Fitting part 6d Female screw 6f Flange part 6g Upper opening 6h Storage chamber 6k Extension part 11 Valve chamber 12 First pipe joint 15 2nd pipe joint 16 Valve seat 16a Valve port 17 Valve body 17a Head 17b Sliding cylinder 17c Connection 17d Space 17k Hole 17l Conduction hole 18 Valve guide 18a Through hole 21 Ceiling 27 Valve spring 28 Back pressure chamber 29 Spring receiving bracket 29a Valve flange 29b Wall part 30 Valve body 32 Bounce spring 33 Bush member 36 Fixture 41 Valve shaft 41a Male screw 41b Flange 41c Protruding part 48 Sealing member 48a L-shaped annular packing 48b Reinforcing plate 48c Leaf spring 48f O Ring 48j Lip part 51 Pressure equalizing hole 52 Guide support 53 Cylindrical part 54 Umbrella-shaped part 60 Case 65 Cylindrical member 66 Rotor accommodating chamber 70 Washer 72 Valve body guide part 72a Side wall 72b Flange 72c Holding part 72c'Upper end surface 72j of holding part Flange 72k Intermediate cylinder 72l Lower end 72m Convex 72u Inner flange 72x Step 72y Step 72z Lower end 72β Flange part 73a Upper outer peripheral surface 73b Lower outer peripheral surface 73f Guide flange 73z Step 74a Upper inner peripheral surface 74b Lower inner peripheral surface 75 Extension Part 78 Claw part 82 Fixing member 84 Spring 92 Valve body guide part 101 Electric valve 107 Valve chamber 119 Valve port 120 Valve body 124 Conduction path 129 Back pressure chamber 137 Seal member 172 Valve body guide part M Central axis L Central axis

Claims (12)

The rotary motion of the rotor housed inside the case is converted into a linear motion by screwing the male screw member and the female screw member, and the valve body housed in the valve body is converted into a linear motion based on this linear motion. An electric valve that moves in the direction of the central axis of the main body and has a back pressure chamber on the upper side of the valve body to introduce the pressure in the valve port into the back pressure chamber.
A side wall extending in the central axis direction in the valve body and accommodating a part of the valve body on the rotor side on the inner diameter side.
A composite type sealing member which is mounted on the inner circumference of the side wall on the valve port side and which is a composite of a sealing portion and an urging portion for urging the sealing portion.
The side wall is provided with a holding portion which is arranged on the valve port side of the seal member and holds the seal member.
An engaging portion that engages with the upper surface of the sealing member is provided on the valve port side of the side wall, and the sealing member is arranged between the engaging portion and the holding portion in the central axial direction. ,
An electric valve characterized by utilizing 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, and abutting the holding portion in the direction of the central axis to fix the holding portion to the side wall. A guide flange protruding toward the outer diameter is formed on the holding portion.
The electric valve according to claim 1, wherein the step formed on the outer peripheral surface by the guide flange is abutted against the lower end portion of the side wall surface, and the holding portion is fixed to the side wall surface. The electric valve according to claim 1, wherein the upper end surface of the holding portion is abutted against the step formed on the inner peripheral surface of the side wall, and the holding portion is fixed to the side wall. The electric valve according to any one of claims 1 to 3, wherein the holding portion regulates a radial position of the valve body on the valve port side. Any of claims 1 to 4, wherein the holding portion includes an extending portion extending to the valve port side with an outer diameter of the outer peripheral surface smaller than that of a portion inserted into the side wall. The electric valve described in item 1. The electric valve according to any one of claims 1 to 5, further comprising an urging spring for urging the valve body. The sixth aspect of claim 6, wherein the urging spring has an inner diameter larger than the diameter of the sliding surface of the valve body, and urges the valve body in the central axis direction in the valve body. Electric valve. The electric valve according to claim 7, wherein at least a part of the valve body is housed inside the urging spring. An inner flange protruding toward the inner diameter is formed on the rotor side of the side wall fixed to the valve body.
A valve flange projecting to the outer diameter side is arranged on the valve body that moves in the central axis direction in the valve body.
The electric valve according to any one of claims 6 to 8, wherein the urging spring is arranged between the inner flange and the valve flange. On the fixed end side of the urging spring, a convex portion is formed that projects toward the inner diameter side of the side wall and locally reduces the inner diameter of the side wall in the central axis direction.
The method according to any one of claims 6 to 9, wherein a wall portion extending in the central axis direction is formed on the movable end side of the urging spring on the inner diameter side of the urging spring. Electric valve. The electric valve according to any one of claims 1 to 10, wherein the seal member is formed by using a lip seal having a lip portion that slides on the valve body. A refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, wherein the electric valve according to any one of claims 1 to 11 is used.

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