JP6952015B2 - Electric valve and refrigeration cycle system - Google Patents

Description

The present invention relates to a motorized valve and a refrigeration cycle system using the motorized 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 background of rationalization of control equipment such as combining multiple electric valves used for flow control into one. Performance that can be exhibited is desired, but the flow control with a relatively large diameter has a large load on the valve body generated by the pressure difference with respect to the thrust of the screw generated by the torque of the magnet, and a large drive for operating the valve body. Power is needed.

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. 5, 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 eliminated, 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 attached to the valve body 120 in order to airtightly separate the back pressure chamber 129 and the valve chamber 107. As shown in FIG. 6, the seal member 137 is formed in an annular shape with an annular reinforcing plate 137b sandwiched between L-shaped annular packings 137a having an L-shaped cross section. The seal member 137 is provided with a leaf spring 137c for urging the lip portion described later so that the outer peripheral surface 137x of the L-shaped annular packing 137a is in close contact with the inner peripheral surface 172a of the valve body guide portion 172, and is slidable. And sealability are compatible.

Japanese Unexamined Patent Publication No. 2017-180639

By the way, in the above-mentioned electric valve 101, as shown in FIG. 7, the L-shaped annular packing 137a has a lip portion 137s having a base portion 137k fixed to the valve body 120 and an outer peripheral surface 137x that is in sliding contact with the valve body guide portion 172. And have. The lip portion 137s has a property of contracting toward the central axis L side at a low temperature.

Therefore, as described above, when the outer peripheral surface 137x of the lip portion 137s of the L-shaped annular packing 137a is slidably contacted with the inner peripheral surface 172a of the valve body guide portion 172 for sealing, the fluid temperature is −40 ° C. or lower. At such a low temperature, the lip portion 137s contracts toward the central axis L side, the degree of adhesion between the outer peripheral surface 137x of the lip portion 137s and the inner peripheral surface 172a of the valve body guide portion 172 is reduced, and the seal member 137 is sealed. There was a problem that the sex was reduced.

Here, the tension of the leaf spring 137c that urges the lip portion 137s of the L-shaped annular packing 137a to the valve body guide portion 172 side so that the sealing property of the sealing member 137 can be maintained even when the fluid temperature becomes low is applied. A method of enhancing is also conceivable. However, in this case, since the sliding resistance between the outer peripheral surface 137x of the lip portion 137s and the inner peripheral surface 172a of the valve body guide portion 172 increases, the operating load increases, which affects the slidability of the valve body 120. There is a risk.

An object of the present invention is an electric valve capable of maintaining the sealing property of the sealing member even at a low temperature, having good slidability of the valve body, and having a stable pressure balance mechanism, and refrigeration using the electric valve. To provide a cycle system.

The electric valve of the present invention
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 valve body guide portion that guides the movement of the valve body in the central axis direction,
It is provided coaxially with the valve body guide portion and includes a lip seal type annular packing and a seal member having a leaf spring.
The annular packing is
The base portion fixed to the valve body guide portion and the base portion
It is provided with at least one lip portion that extends from the valve body side of the base portion in the central axial direction, is in sliding contact with the outer peripheral surface of the valve body, and contracts to the valve body side at a low temperature .
The leaf spring is characterized in that the lip portion is urged toward the valve body side in which the lip portion contracts at a low temperature .

In this way, by arranging the annular packing coaxially with the valve body guide portion and sliding the lip portion on the outer peripheral surface of the valve body, the direction in which the lip portion contracts at low temperature and the lip portion are on the outer peripheral surface of the valve body. Since the direction of close contact is the same, the sealing property of the sealing member at low temperature can be maintained. In this case, it is not necessary to increase the tension of the urging portion of the leaf spring, which will be described later, in order to maintain the degree of adhesion of the L-shaped annular packing, so that the slidability of the valve body can also be maintained. That is, it is possible to provide an electric valve in which the sealing property of the sealing member can be maintained even at a low temperature, the slidability of the valve body is good, and the pressure balance mechanism is stable.
Further, the urging force of the leaf spring is aligned with the direction in which the urging portion of the leaf spring urges the lip portion of the annular packing to the same valve body side as the direction in which the lip portion of the L-shaped annular packing contracts when the fluid temperature is low. Is not reduced by the contraction force of the lip portion, and the sealing property is not deteriorated even when the fluid temperature is low. In addition, since the urging force of the leaf spring and the contraction force of the lip portion both go toward the valve body side, it is not necessary to increase the urging force of the leaf spring, and good slidability of the valve body can be maintained, so that the operability is stable. It is possible to realize a pressure balance mechanism.

Further, the electric valve of the present invention is
The seal member is
One of the annular packings having the lip portion extended to the rotor side,
The lip portion is provided with another annular packing extending to the valve port side.

By arranging a pair of annular packings having different lip orientations vertically in this way, the pressure in the back pressure chamber is higher than the pressure in the valve chamber (the space formed on the outside of the valve body in the valve body). In both high pressure and low pressure, fluid leakage between the back pressure chamber and the valve chamber can be prevented, and a pressure-balanced electric valve with stable operability can be realized. ..

Further, the electric valve of the present invention is
The annular packing is
It is characterized in that it is an L-shaped annular packing having an L-shaped cross-sectional shape in the axial direction.

By arranging the pair of L-shaped annular packings vertically in this way, it is possible to prevent fluid leakage between the back pressure chamber and the valve chamber. Further, the L-shaped annular packing having excellent slidability makes it possible to realize a pressure-balanced electric valve with stable operability.

Further, the electric valve of the present invention is
One of the L-shaped annular packings having the lip portion extended to the rotor side,
It is provided with another L-shaped annular packing which is arranged on the valve port side of the annular packing and has the lip portion extended to the valve port side.
The base portion of one L-shaped annular packing and the other L-shaped annular packing are laminated in the central axial direction.

By laminating the L-shaped annular packing in the valve axis direction in this way, good sliding sealability is obtained in both cases where the pressure in the back pressure chamber becomes higher than the pressure in the valve chamber and when the pressure becomes lower. It is possible to realize a pressure balance mechanism having a stable operability.

Further, the electric valve of the present invention is
The leaf spring
A leaf spring fixing portion arranged adjacent to the base portion of the annular packing in the central axial direction, and a leaf spring fixing portion.
The leaf spring fixing portion is provided with an urging portion that bends and extends in the central axial direction and urges the lip portion to the valve body side of the annular packing.

In this way, by providing the valve body side of the leaf spring with an urging portion that bends and extends in the central axis direction, the lip portion of the annular packing can be reliably urged, and stable sealing performance can be obtained. Can be done.

Further, the electric valve of the present invention is
The seal member is
The leaf spring having the urging portion extended to the rotor side, and the leaf spring.
The urging portion is provided with another leaf spring extending to the valve port side.
The urging portion of the leaf spring urges the lip portion of the annular packing.
The urging portion of the other leaf spring urges the lip portion of the other annular packing.

In this way, in both the combination of the upper leaf spring and the annular packing and the combination of the lower leaf spring and the annular packing, the urging direction of the urging portion of the leaf spring and the contraction direction of the lip portion at low temperature of the fluid are determined. By using the same direction, the urging force of the leaf spring is not reduced by the contraction force of the lip portion in either the upper or lower annular packing, and the sealing property is not deteriorated even when the fluid temperature is low. Further, in either the upper or lower annular packing, the urging force of the leaf spring and the contraction force of the lip portion both go toward the valve body side, so that it is not necessary to increase the urging force of the leaf spring. Therefore, good slidability of the valve body can be maintained.

Further, the electric valve of the present invention is
The valve body guide portion is
A cylindrical side wall extending in the central axis direction and having a first step formed on the inner peripheral surface, and a tubular side wall.
An annular fixing part and
A valve guide portion that guides the valve body in the direction of the central axis,
With
In a state where the seal member is sandwiched between the fixing portion and the valve guide portion,
The fixing portion is fixed by abutting against the first step.
The valve guide portion is fixed to the valve port side end portion of the side wall.

In this way, by using the step and abutting the fixed portion in the valve central axis direction and fixing it to the side wall, the position of the seal member in the central axial direction is stabilized and the amount of crushing of the seal member is also stable. The slidability and sealing property of the lip portion can be stabilized.

Further, the electric valve of the present invention is
A second step is formed on the outer peripheral side of the valve guide portion.
The valve guide portion is characterized in that the second step is abutted against the lower end of the side wall and fixed to the side wall.

By abutting the step against the lower end of the side wall and fixing the valve guide portion to the side wall in this way, the position of the seal member in the central axial direction is stabilized, and the amount of crushing of the seal member is also stabilized. The slidability and sealing property can be stabilized.

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 motorized valve described above.

Such an electric valve is suitable as a refrigeration cycle system because it can accurately adjust the opening degree of the valve and control the flow rate as a control valve.

According to the present invention, an electric valve capable of maintaining the sealing property of the sealing member even at a low temperature, having good slidability of the valve body, and having a stable pressure balance mechanism, and refrigeration using the electric valve. A cycle system can be provided.

It is the schematic sectional drawing of the electric valve which concerns on embodiment. It is an enlarged view of the main part of the electric valve which concerns on embodiment. It is an enlarged view which shows the seal part of the electric valve which concerns on embodiment. It is a figure which shows the seal member which concerns on other embodiment. It is the schematic sectional drawing of the conventional electric valve. It is an enlarged view of the main part of a conventional electric valve. It is an enlarged view 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 cylindrical 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 inside 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 inside 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 cylindrical 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 cylindrical small diameter portion 6a of the valve shaft holder 6.

Further, a pressure equalizing hole 51 is formed on the side surface of the cylindrical 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 cylindrical 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. Is interposed with a seal member 48 that airtightly separates the back pressure chamber 28 and the valve chamber 11. The seal member 48 is arranged coaxially with the valve body guide portion 72.

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 has a substantially cylindrical head portion 17a fixed to the valve guide 18 via an annular fixture 36, a cylindrical sliding cylinder portion 17b having a columnar space 17d formed therein, and a head portion. It is composed of a connecting portion 17c that integrally connects the 17a and the sliding cylinder portion 17b. Further, inside the head 17a, a vertical hole portion 17k and a horizontal conduction hole 17l 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 that penetrates the inside, and includes a tubular side wall 72a extending in a coaxial direction with the central axis M direction, an annular fixing portion 72b for fixing the seal member 48, and a seal member 48. A valve guide portion 72c for fixing and sliding the outer peripheral surface of the valve body 17 in the direction of the central axis M is provided. Further, the side wall 72a has a flange portion 72j located at the uppermost position, an intermediate cylinder portion 72k below the flange portion 72j, and a lower end portion 72l further below the flange portion 72j, and is formed by cutting or the like.

The valve body guide portion 72 is positioned at a predetermined position in the valve body 30 by fixing 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.

Further, as shown in FIG. 2, a first step 72x is formed between the intermediate cylinder portion 72k and the lower end portion 72l of the valve body guide portion 72, and a second step 72x is formed on the outer peripheral side of the valve guide portion 72c. A step 72y is formed. The fixing portion 72b abuts the upper end of the outer periphery against the first step 72x and is fixed to the valve body guide portion 72, and the valve guide portion 72c abuts the second step 72y against the lower end of the inner circumference of the lower end portion 72l to valve the valve. It is fixed to the body guide 72.

Further, the seal member 48 is sandwiched between the fixing portion 72b and the valve guide portion 72c in the direction of the central axis M. By abutting the second step 72y against the inner peripheral lower end of the lower end portion 72l, the seal member 48 eliminates the variation in the amount of crushing in the central axis M direction, and the sealability and slidability of the lip portion 48j, which will be described later, are eliminated. Is stable. The fixing portion 72b and the valve guide portion 72c are each made of a metal such as stainless steel.

Further, as shown in FIG. 1, a spring receiving metal fitting 29, which is a truncated cone type cylinder, is arranged on the outer periphery of the connecting portion 17c of the valve body 17. The spring receiving metal fitting 29 has a 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 flange 29a and the fitting portion 6c of the valve shaft holder 6. As a result, the valve body 17 is pushed downward, and 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, since the valve body 17 is urged by the urging spring 32 having an inner diameter larger than the outer peripheral surface of the valve body 17, the inclination of the valve body 17 can be suppressed.

Next, a main part of the electric valve 2 according to the embodiment will be described. FIG. 2 is an enlarged view of a main part of the electric valve 2 according to the embodiment. As shown in FIG. 2, a seal member 48 is arranged on the inner diameter side of the lower end portion 72l of the valve body guide portion 72.

The seal member 48 is formed by laminating an L-shaped annular packing 48a, a reinforcing plate 48b, and a leaf spring 48c. The L-shaped cyclic packing 48a is made of a fluororesin material such as PTFE (polytetrafluoroethylene) or PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer). Further, the reinforcing plate 48b is formed of, for example, a resin material such as PPS (polyphenylene sulfide) or a metal material such as brass or brass, and the leaf spring 48c is formed of a metal material such as stainless steel. ..

Here, the L-shaped annular packing 48a is an annular component having an L-shaped cross section, and includes a base portion 48k and a lip portion 48j as shown in FIG. The base portion 48k is sandwiched between the annular reinforcing plate 48b and the annular leaf spring 48c and fixed to the valve body guide portion 72. On the other hand, the lip portion 48j extends from the valve body 17 side of the base portion 48k to the upper side (rotor 4 side) or the lower side (valve port 16a side) in the central axis M direction, and is in sliding contact with the outer peripheral surface of the valve body 17. There is. Then, the L-shaped annular packing 48a having the lip portion 48j extended upward is arranged above the reinforcing plate 48b, and the L-shaped annular packing 48a extending the lip portion 48j downward is arranged below the reinforcing plate 48b. Has been done.

That is, a pair of L-shaped annular packings 48a in which the lip portions 48j are extended in different directions are laminated on the valve body guide portion 72 in the central axis M direction with the reinforcing plate 48b interposed therebetween.
The reinforcing plate 48b is an annular component sandwiched between two L-shaped annular packings 48a, and is arranged so that the inner peripheral surface does not come into contact with the outer peripheral surface of the valve body 17.

Further, the leaf spring 48c is an annular component having a substantially L-shaped cross section, and includes a leaf spring fixing portion 48p and an urging portion 48q. Here, the leaf spring fixing portion 48p is arranged adjacent to the base portion 48k of the L-shaped annular packing 48a in the central axis M direction. Specifically, the leaf spring fixing portion 48p located on the upper side is sandwiched between the L-shaped annular packing 48a and the fixing portion 72b, and the leaf spring fixing portion 48p located on the lower side is sandwiched between the L-shaped annular packing 48a and the valve. It is sandwiched between the guide portions 72c.

On the other hand, the urging portion 48q is bent from the valve body 17 side of the leaf spring fixing portion 48p and extends upward or downward in the central axis M direction, and the lip portion 48j is moved to the valve body 17 side of the L-shaped annular packing 48a. I'm urging. The direction in which the urging portion 48q urges the lip portion 48j is the same direction as the direction in which the lip portion 48j contracts (the valve body 17 side of the L-shaped annular packing 48a).

Then, the leaf spring 48c with the urging portion 48q facing upward is arranged on the upper side of the L-shaped annular packing 48a with the lip portion 48j facing upward, and the urging portion 48q facing upward is the lip portion 48j facing upward. Is urging. Further, a leaf spring 48c with the urging portion 48q facing downward is arranged below the L-shaped annular packing 48a with the lip portion 48j facing downward, and the urging portion 48q facing downward is placed on the lower side. The facing lip portion 48j is urged. The angle between the base portion 48k and the urging portion 48q is formed so as to be an obtuse angle than the angle between the leaf spring fixing portion 48p and the lip portion 48j of the L-shaped annular packing 48a.

Here, when the fluid temperature of the electric valve 2 becomes a low temperature of −40 ° C. or lower, the lip portion 48j contracts toward the valve body 17 side of the L-shaped annular packing 48a, so that the lip portion 48j and the valve body are contracted at a low temperature. The degree of adhesion of the outer peripheral surface of 17 is further increased.

According to the electric valve 2 of this embodiment, the L-shaped annular packing 48a is arranged on the valve body guide portion 72 side, and the lip portion 48j is slidably contacted with the outer peripheral surface of the valve body 17, so that the lip portion 48j is at a low temperature. Since the direction in which the lip portion 48j contracts and the direction in which the lip portion 48j comes into close contact with the outer peripheral surface of the valve body 17 are in the same direction, the sealing property of the sealing member 48 at a low temperature can be maintained. In this case, since it is not necessary to increase the tension of the urging portion 48q of the leaf spring 48c in order to maintain the degree of adhesion of the L-shaped annular packing 48a, the slidability of the valve body 17 can also be maintained. That is, it is possible to provide the electric valve 2 in which the sealing property of the sealing member 48 can be maintained even at a low temperature, the slidability of the valve body 17 is good, and the pressure balance mechanism is stable.

Further, by arranging a pair of L-shaped annular packings 48a having different directions of the lip portions 48j vertically, the pressure in the back pressure chamber 28 becomes higher than the pressure in the valve chamber 11, or the pressure becomes low. In either case, it is possible to prevent fluid from leaking between the back pressure chamber 28 and the valve chamber 11, and realize a pressure-balanced electric valve 2 with stable operability even when the flow direction of the fluid is reversed. be able to.

Further, by aligning the direction in which the urging portion 48q of the leaf spring 48c urges the lip portion of the annular packing on the valve body 17 side which is the same as the direction in which the lip portion 48j of the L-shaped annular packing 48a contracts, the leaf spring 48c The urging force of the lip portion 48j can be prevented from being reduced by the contraction force of the lip portion 48j. Further, since the urging force of the leaf spring 48c and the contraction force of the lip portion 48j are both directed toward the valve body 17, it is not necessary to increase the urging force of the leaf spring 48c, and good slidability can be maintained.

In the above-described embodiment, the seal member 48 does not necessarily have to include the leaf spring 48c. Even in this case, at low temperature, the lip portion 48j of the L-shaped annular packing 48a contracts toward the valve body 17 in the same direction as the urging portion 48q of the leaf spring 48c contracts, so that the lip portion 48j and the valve body at low temperature contract. The degree of adhesion of the outer peripheral surface of 17 can be maintained.

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 the annular packing may be a lip seal type having a lip portion, and is not necessarily the case. The cross section does not have to be L-shaped.

Further, in the above-described embodiment, the sealing member 48 does not have to be provided with the reinforcing plate 48b. For example, a seal member may be a seal member in which the base portions 48k of the L-shaped annular packing 48a having the lip portion 48j extended in the vertical direction are adjacent to each other and the L-shaped annular packing 48a is laminated in the central axis M direction. .. Further, as shown in FIG. 4, a Y-shaped sealing member 49 may be used in which the lip portion 48j shares the base portion 48k of the L-shaped annular packing 48a extending in the vertical direction. Further, the upper and lower annular packings may be directly overlapped and arranged without sharing the substrate portion. Even in these cases, it is possible to provide the electric valve 2 in which the sealing property of the sealing member 48 can be maintained at a low temperature, the slidability of the valve body 17 is good, and the pressure balance mechanism is stable.

Further, in the above-described embodiment, the seal member 48 does not necessarily have to include a pair of upper and lower annular packings. For example, it may be provided with only one of an annular packing in which the lip portion is extended downward and an annular packing in which the lip portion is extended upward. In this case, the seal member 48 having only the annular packing with the lip portion extending downward always has a valve from the first pipe joint 12 in which the pressure in the valve chamber 11 is higher than the pressure in the back pressure chamber 28. It can be effectively used when a fluid flows through the second pipe joint 15 through the chamber 11. On the other hand, in the seal member 48 having only the annular packing with the lip portion extended upward, the pressure in the back pressure chamber 28 is always higher than the pressure in the valve chamber 11, from the second pipe joint 15 to the valve chamber 11. It can be effectively used when flowing a fluid through the first pipe joint 12.

Further, in the above-described embodiment, the case where the lip portion 48j contracts when the fluid temperature becomes a low temperature of −40 ° C. or lower is described as an example, but the temperature at which the lip portion 48j contracts, that is, The low temperature may be higher than −40 ° C. For example, when the fluid temperature becomes a low temperature of 0 ° C. or lower, the lip portion 48j begins to contract toward the valve body 17, and as the fluid temperature decreases, the degree of adhesion between the lip portion 48j and the outer peripheral surface of the valve body 17 increases. In some cases.

Further, the electric valve 2 of the above-described embodiment is, for example, an expansion valve or a flow rate 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 roads.

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 metal fittings 29a Flange 30 Valve body 32 Bounce spring 33 Bush member 36 Fixture 41 Valve shaft 41a Male screw 41b Kneck part 41c Protruding part 48 Sealing member 48a L-shaped annular packing 48b Reinforcing plate 48c Leaf spring 48j Lip part 48k Base part 48p Leaf spring fixing part 48q Biasing part 49 Sealing member 49j Lip part 51 Pressure equalizing hole 52 Guide support 53 Cylindrical part 54 Umbrella-shaped part 60 Case 65 Cylinder member 66 Rotor accommodating chamber 70 Washer 72 Valve body guide part 72a Side wall 72b Fixing Part 72c Valve guide part 72j Flange part 72k Intermediate cylinder part 72l Lower end part 72x First step 72y Second step 101 Electric valve 107 Valve chamber 119 Valve port 120 Valve body 124 Conduction path 129 Back pressure chamber 137 Seal member 137a L-shaped Circular packing 137b Reinforcing plate 137c Leaf spring 137k Base part 137s Lip part 137x Outer peripheral surface 172 Valve body guide part 172a Inner peripheral surface of valve body guide part L Central axis M Central axis

Claims (9)

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 valve body guide portion that guides the movement of the valve body in the central axis direction,
It is provided coaxially with the valve body guide portion and includes a lip seal type annular packing and a seal member having a leaf spring.
The annular packing is
The base portion fixed to the valve body guide portion and the base portion
It is provided with at least one lip portion that extends from the valve body side of the base portion in the central axial direction, is in sliding contact with the outer peripheral surface of the valve body, and contracts to the valve body side at a low temperature .
The leaf spring is an electric valve characterized in that the lip portion is urged toward the valve body side in which the lip portion contracts at a low temperature. The seal member is
One of the annular packings having the lip portion extended to the rotor side,
The electric valve according to claim 1, further comprising the other annular packing having the lip portion extended to the valve port side. The annular packing is
The electric valve according to claim 1 or 2, wherein the axial cross-sectional shape is an L-shaped L-shaped annular packing. One of the L-shaped annular packings having the lip portion extended to the rotor side,
It is provided with the other L-shaped annular packing which is arranged on the valve port side of the one said annular packing and whose lip portion extends to the valve port side.
The electric valve according to claim 3, wherein the base portion of the L-shaped annular packing and the other L-shaped annular packing are laminated in the central axial direction. The leaf spring
A leaf spring fixing portion arranged adjacent to the base portion of the annular packing in the central axial direction, and a leaf spring fixing portion.
The valve body side of said plate spring fixing portions, extending in the central axis direction is bent, according to claim 1, said lip portion, characterized in that it comprises a biasing unit that biases the valve body side of said annular packing The electric valve according to any one of the items to 4. The seal member is
The leaf spring having the urging portion extended to the rotor side, and the leaf spring.
The urging portion is provided with another leaf spring extending to the valve port side.
The urging portion of the leaf spring urges the lip portion of the annular packing.
The electric valve according to claim 5 , wherein the urging portion of the other leaf spring urges the lip portion of the other annular packing. The valve body guide portion is
A cylindrical side wall extending in the central axis direction and having a first step formed on the inner peripheral surface, and a tubular side wall.
An annular fixing part and
A valve guide portion for guiding the valve body in the central axis direction is provided.
In a state where the seal member is sandwiched between the fixing portion and the valve guide portion,
The fixing portion is fixed by abutting against the first step.
The electric valve according to any one of claims 1 to 6 , wherein the valve guide portion is fixed to the valve port side end portion of the side wall. A second step is formed on the outer peripheral side of the valve guide portion.
The electric valve according to claim 7 , wherein the valve guide portion abuts the second step against the lower end of the side wall and is fixed to the side wall. 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 8 is used.

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