Patent Application
20230272868
The present invention relates to a valve used in an air conditioning system.
An air conditioning system has a refrigeration cycle which mainly includes a compressor compressing a refrigerant to become superheated steam, a condenser cooling the refrigerant sent from the compressor to become a supercooled liquid, an expansion valve expanding the refrigerant sent from the condenser to become moist steam, and an evaporator heating the refrigerant sent from the expansion valve to become saturated steam and in which the refrigerant circulates in order of the compressor, the condenser, the expansion valve, and the evaporator.
For example, a valve of Patent Citation 1 is an electronic expansion valve and is able to adjust a valve opening degree between a valve seat formed in a valve housing and a valve body by driving the valve body in a valve opening direction by an electromagnetic force of a solenoid which is a drive source against an urging force of a spring. Further, a current value applied to the solenoid is set on the basis of the temperature or pressure of the refrigerant having passed through a condenser and a valve opening degree is adjusted, so that a supercooling degree of the condenser is maintained constant.
Further, it is also known to adjust the dryness of moist steam so that all refrigerants become saturated steam after the refrigerants pass through an evaporator by adjusting a valve opening degree of an expansion valve on the basis of the temperature or pressure of the refrigerant before or after passing through the evaporator.
Patent Citation 1: JP 2001-153498 A (page 2, FIG. 1)
Since the valve of Patent Citation 1 has a poppet valve structure in which a through-passage is closed by the valve body and the valve seat, the through-passage can be reliably closed. However, in the valve of Patent Citation 1, since the refrigerant having a high-pressure primary pressure is supplied from the condenser to the through-passage, there is concern that the valve opening degree with respect to the current value applied to the solenoid becomes slightly different due to the pressure of the refrigerant even when a force caused by the pressure of the refrigerant is applied to the valve body in the valve opening direction in addition to a driving force of the solenoid.
The present invention has been made by focusing on such a problem and an object of the present invention is to provide a valve having a high valve opening adjustment accuracy.
In order to solve the foregoing problem, a valve according to the present invention includes: a valve housing provided with an inlet port and an outlet port; a valve body driven by a drive source; a valve seat on which the valve body sits; a spring configured to urge the valve body in a direction opposite to a driving direction by the drive source; and a communication means configured to communicate the inlet port with a back surface side space of the valve body. According to the aforesaid feature of the present invention, in a state in which the inlet port and the back surface side space of the valve body communicate with each other by the communication means, a fluid, for example, the refrigerant of a primary pressure flowing from the condenser into the inlet port is supplied to the back surface side space of the valve body. Accordingly, since it is possible to reduce the influence of the force of the refrigerant of the primary pressure applied to the valve body, the valve has a high valve opening adjustment accuracy. Further, since the refrigerant of the primary pressure is supplied to the back surface side space of the valve body, it is possible to reduce the driving force of the drive source in the vicinity of the valve closure position. In addition, the back surface side space of the valve body is a space on the side of the drive source in relation to the valve seat.
It may be preferable that the back surface side space of the valve body communicates with the outlet port through a throttle. According to this preferable configuration the back surface side space of the valve body is maintained at a pressure close to a primary pressure by the throttle.
It may be preferable that the throttle is formed by a guide hole formed in the valve housing and a valve body inserted to the guide hole. According to this preferable configuration, the throttle is a clearance formed between the valve body and the guide hole of the valve housing. Accordingly, the valve has a simple structure.
It may be preferable that the communication means is a through-hole which communicates with the inlet port and the back surface side space of the valve body. According to this preferable configuration, the communication means has a simple structure.
It may be preferable that the communication means constitutes a control pressure operation valve which controls a communication between the inlet port and the back surface side space of the valve body, and the control pressure operation valve includes a through-hole communicating with the inlet port and the back surface side space of the valve body, an urging means disposed in the through-hole, and an operation valve body urged in a valve closing direction by the urging means. According to this preferable configuration, the high primary pressure moves the operation valve body against the urging force of the urging means, opens the control pressure operation valve, and communicates the inlet port with the back surface side space of the valve body through the through-hole. Accordingly, the communication means can reduce the influence of the primary pressure applied to the valve body when opening the control pressure operation valve. Therefore, particularly when the primary pressure has a high pressure and the differential pressure between the primary pressure and a secondary pressure becomes large, the valve has a high valve opening adjustment accuracy. Further, the control pressure operation valve is used to control the refrigerant passage amount if necessary. Therefore, the leakage amount of the refrigerant of the primary pressure is small.
It may be preferable that the valve has a normal close structure. According to this preferable configuration, the valve is suitable as, for example, an expansion valve which controls a refrigerant from a condenser to an evaporator.
Modes for carrying out a valve according to the present invention will be described below with reference to embodiments.
An expansion valve which is a valve according to a first embodiment of the present invention will be described with reference to
As shown in
First, the refrigeration cycle R will be described. The refrigeration cycle R is configured to circulate the refrigerant in order of the compressor C, the heat exchanger H1, the expansion valve V1, and the heat exchanger H2 in a heating mode. The refrigerant becomes superheated steam by the compressor C, becomes a supercooled liquid by the heat exchange with the indoor air using the heat exchanger H1, becomes moist steam by being depressurized from a high-pressure primary pressure to a low-pressure secondary pressure using the expansion valve V1, and becomes saturated steam by the heat exchange with the outdoor air using the heat exchanger H2. Further, the indoor air is heated by the heat exchange with the heat exchanger H1. That is, in the heating mode, the heat exchanger H1 serves as a condenser and the heat exchanger H2 serves as an evaporator.
Further, the refrigeration cycle R is configured to circulate the refrigerant in order of the compressor C, the heat exchanger H2, the expansion valve V1, and the heat exchanger H1 in a cooling mode. The refrigerant becomes superheated steam by the compressor C, becomes a supercooled liquid by the heat exchange with the outdoor air using the heat exchanger H2, becomes moist steam by being depressurized from a high-pressure primary pressure to a low-pressure secondary pressure using the expansion valve V1, and becomes saturated steam by the heat exchange with the indoor air using the heat exchanger H1. Further, the indoor air is cooled by the heat exchange with the heat exchanger H1. That is, in the cooling mode, the heat exchanger H1 serves as an evaporator and the heat exchanger H2 serves as a condenser.
In addition, in the following description, the refrigeration cycle R is used for heating unless otherwise specified. Similarly, the heat exchanger H1 is referred to as a condenser H1 and the heat exchanger H2 is referred to as an evaporator H2 on the basis of the heating mode.
Referring to
In this embodiment, the valve 50 includes a valve body 51 and a valve seat 40a. The valve seat 40a is formed in a tubular valve seat member 40 press-fitted into a concave portion 10a of a valve housing 10. When a tapered surface 52a at a front end portion 52 of the valve body 51 comes into contact with and separates from the valve seat 40a, the valve 50 is opened and closed.
Next, the structure of the expansion valve V1 will be described. As shown in
As shown in
As shown in
The small-diameter portion 53 is a columnar body extending from the axial right end of the front end portion 52 toward the axial right side with a constant cross-section and is formed to have a diameter smaller than a through-passage 40b to be described later.
The large-diameter portion 54 is a columnar body having a diameter larger than that of the small-diameter portion 53 and both axial ends gradually decrease in diameter.
The base portion 55 is a columnar body which extends from the axial right end of the large-diameter portion 54 toward the axial right side with a constant cross-section. The base portion 55 has a diameter smaller than that of the large-diameter portion 54.
As shown in
In addition, when the refrigeration cycle R is used for cooling, the outlet port 12 communicates with the heat exchanger H1 and the inlet port 11 communicates with the heat exchanger H2.
The valve seat member 40 is integrally fixed to the concave portion 10a in a substantially sealed state by being press-fitted from the axial left side.
As shown in
Further, a cross-sectional area RS1 of a portion sitting on the valve seat 40a in the tapered surface 52a of the front end portion 52 is substantially the same as a maximum cross-sectional area RS2 of the large-diameter portion 54 of the valve body 51. In other words, the cross-sectional area RS1 is the effective pressure receiving area of the front end portion 52 and the maximum cross-sectional area RS2 is the effective pressure receiving area of the large-diameter portion 54.
Returning to
The inner peripheral surface of the valve housing 10 is provided with a guide hole 10b which is formed on the side of the solenoid 80 in relation to the valve seat 40a and the valve chamber 20 so that the outer peripheral surface of the large-diameter portion 54 of the valve body 51 is slidable therethrough. In addition, a minute clearance which is a throttle 90 is formed between the inner peripheral surface of the guide hole 10b and the outer peripheral surface of the valve body 51 when the peripheral surfaces are slightly separated from each other. Accordingly, the valve body 51 is smoothly and relatively movable in the axial direction with respect to the valve housing 10.
Further, the valve housing 10 is provided with a concave portion 10c in which the inner diameter side of the axial right end is recessed toward the axial left side. A flange portion 82d of a center post 82 is press-fitted and fixed to the concave portion 10c in a sealed state from the axial right side. Furthermore, a casing 81 is fixed to the right end of the valve housing 10 from the axial right side of the flange portion 82d. Accordingly, the valve housing 10, the casing 81, and the center post 82 are integrally connected to each other. In addition, an opening end on the side of the solenoid 80 in the guide hole 10b is formed on the inner diameter side of the bottom surface of the concave portion 10c of the valve housing 10.
Further, a through-hole 21 which is a communication means extending in the axial direction is formed between the bottom portions of the concave portions 10a and 10c at both axial ends of the valve housing 10. The through-hole 21 is formed to have a constant cross-section and communicates with the inlet port 11 and a space S inside the solenoid 80.
As shown in
The center post 82 is formed of a rigid body which is a magnetic material such as iron or silicon steel and includes a cylindrical portion 82b and a flange portion 82d. The cylindrical portion 82b is provided with an insertion hole 82c which extends in the axial direction and through which the valve body 51 is inserted. The flange portion 82d is formed in an annular shape which extends toward the outer diameter direction from the outer peripheral surface at the axial left end portion of the cylindrical portion 82b.
The space S inside the solenoid 80 is a space mainly inside the sleeve 87 located on the back surface side of the valve body 51 partitioned from the valve chamber 20 and includes a space inside the concave portion 10c and the center post 82.
Further, the space S communicates with the downstream side of the valve seat 40a of the valve chamber 20 through the throttle 90.
Accordingly, the refrigerant of a primary pressure P1 can also flow into the space S through the inlet port 11 and the through-hole 21 and flow out from the outlet port 12 through the throttle 90 and the valve chamber 20.
Next, the operation of the expansion valve V1 and mainly the opening and closing operation thereof will be described.
First, a state in which the expansion valve V1 is not energized will be described. As shown in
In the closed state, the valve 50 does not allow the refrigerant to pass therethrough. On the other hand, the downstream side of the valve seat 40a of the valve chamber 20 communicates with the evaporator H2 having a relatively low pressure through the outlet port 12. Therefore, a fluid having a secondary pressure P2 which is relatively lower than the primary pressure P1 flows into the downstream side of the valve seat 40a of the valve chamber 20.
As shown in
The valve 50 expands the refrigerant which passes therethrough in an open state. Accordingly, the valve 50 in an open state can reduce the pressure of the refrigerant from the primary pressure P1 to the secondary pressure P2. That is, the fluid of the secondary pressure P2 flows into the downstream side of the valve seat 40a in the valve chamber 20.
Further, a minute gap constituting the throttle 90 is narrower than the maximum opening area of the valve 50. Therefore, the refrigerant flowing into the space S during normal control is maintained at a pressure closer to the primary pressure P1.
Next, a force Frod applied to the valve body 51 will be described. As indicated by the fine dot pattern in
Accordingly, the primary pressure P1 and the secondary pressure P2 of the refrigerant are respectively applied to the valve body 51 in the valve closing direction and the valve opening direction in addition to the urging force Fsp of the coil spring 85 applied in the valve closing direction and the driving force Fsol of the solenoid 80 applied in the valve opening direction in an energized state.
More specifically, a force applied from the refrigerant to the valve body 51 with the valve closing direction as positive and the valve opening direction as negative is obtained by subtracting the force Fp2=P2×(RS1−RS2) due to the secondary pressure P2 from the force Fp1=P1×(RS1−RS2) due to the primary pressure P1.
From these facts, the force Frod=Fsp+Fp1−Fp2 is applied to the valve body 51 with the valve closing direction as positive and the valve opening direction as negative. As described above, since the cross-sectional areas RS1 and RS2 are substantially the same, the forces Fp1 and Fp2 are zero. Therefore, the urging force Fsp of the coil spring 85 and the driving force Fsol of the solenoid 80 (i.e., Frod=Fsp+Fsol) are mainly applied to the valve body 51.
As described above, the refrigerant of the primary pressure P1 flowing from the condenser H1 into the inlet port 11 is supplied to the space S in a state in which the inlet port 11 and the space S inside the solenoid 80 communicate with each other by the through-hole 21. Accordingly, since both the force Fp1 due to the primary pressure P1 and the force Fp2 due to the secondary pressure P2 are zero, the through-hole 21 can reduce the influence of the force of the refrigerant of the primary pressure applied to the valve body 51. Therefore, the expansion valve V1 has a high valve opening adjustment accuracy of the valve 50.
Further, mainly when the driving force Fsol of the solenoid 80 exceeds the urging force Fsp, of the coil spring 85, the valve 50 is opened. Therefore, since the refrigerant of the primary pressure supplied to the back surface side space S of the valve body 51 is supplied through the through-hole 21, it is possible to reduce the driving force of the solenoid 80 in the vicinity of the valve closure position, that is, when the valve 50 in a closed state is just opened and when the valve 50 is maintained in a slightly opened state.
Additionally, in this embodiment, a configuration has been described in which the cross-sectional area RS1 and the cross-sectional area RS2 are substantially the same, but the present invention is not limited thereto. That is, the cross-sectional area RS1 may be larger than the cross-sectional area RS2 (RS1>RS2) or the cross-sectional area RS1 may be smaller than the cross-sectional area RS2 (RS1<RS2). Even in such a configuration, the force for the overlapping area is canceled and only the force for the area of the difference from the cross-sectional areas RS1 and RS2 is applied to the valve body 51. Therefore, the refrigerant of the primary pressure supplied to the back surface side space S of the valve body 51 can reduce the influence on the valve body 51 due to the pressure of the refrigerant.
Further, in this embodiment, an example has been described in which the pressure of the refrigerant inside the space S is the primary pressure, but the present invention is not limited thereto. That is, the pressure may be close to the primary pressure.
Further, the throttle 90 is a clearance formed between the valve body 51 and the guide hole 10b of the valve housing 10. Accordingly, the expansion valve V1 has a simple structure.
Further, the communication means of this embodiment is the through-hole 21 which communicates with the inlet port 11 and the space S. Therefore, the communication means has a simple structure.
Further, the expansion valve V1 has a normal close structure in which the valve 50 is closed in a non-energized state. Therefore, the expansion valve V1 can maintain the pressure on the side of the condenser H1 at the primary pressure P1 in a non-energized state. That is, the expansion valve can maintain the refrigerant on the side of the condenser H1 as a supercooled liquid even when the refrigeration cycle R is stopped. Accordingly, the expansion valve V1 is suitable as the expansion valve since all the refrigerants can be transferred to saturated steam in the evaporator H2 to heat the refrigerant as in the normal control even immediately after the refrigeration cycle R is started.
Further, in the expansion valve V1, the direction in which the refrigerant of the primary pressure P1 is applied to the front end portion 52 of the valve body 51 is the same as the valve closing direction. Therefore, even when the pressure of the primary pressure P1 suddenly increases, the differential pressure between the pressure inside the inlet port 11 and the pressure inside the space S is applied to the valve body 51 in the valve closing direction. Accordingly, the expansion valve V1 can prevent the valve body 51 from being unintentionally opened.
An expansion valve as a valve according to a second embodiment of the present invention will be described with reference to
As shown in
An operation valve body 31 and a return spring 32 which is an urging means are disposed in the large-diameter hole portion 23. The operation valve body 31 has a ball shape. In the return spring 32, the axial right end is fixed to the center post 82 and the axial left end comes into contact with the operation valve body 31. The operation valve body 31 and the return spring 32 constitute a control pressure operation valve 30 which controls the communication between the inlet port 11 and the space S inside the solenoid 80.
As shown in
At this time, as indicated by the fine dot pattern in
Further, as shown in
At this time, the primary pressure P1 Fp11 inside the inlet port 11 exceeding the pressure Fp12 of the refrigerant inside the space S and the urging force FSP of the return spring 32 is applied to the operation valve body 31 toward the axial right side (Fp11>FSP+Fp12).
As in the state of
In this way, the high primary pressure P1 inside the inlet port 11 moves the operation valve body 31 against the urging force (FSP) of the return spring 32 and opens the control pressure operation valve 30 so that the inlet port 11 and the space S inside the solenoid 80 communicate with each other through the through-hole 210. Accordingly, the through-hole 210 can reduce the influence of the pressure of the refrigerant applied to the valve body 51 at the time of opening the control pressure operation valve 30. Therefore, particularly when the primary pressure P1 has a high pressure and the differential pressure between the primary pressure P1 and the secondary pressure P2 becomes large, the expansion valve V2 has a high valve opening adjustment accuracy of the valve 50. Further, the control pressure operation valve 30 is used to control the refrigerant passage amount if necessary. Therefore, the leakage amount of the refrigerant of the primary pressure P1 is small.
Further, the refrigerant inside the space S can be smoothly released from the minute gap between the inner peripheral surface of the guide hole 10b and the outer peripheral surface of the valve body 51, that is, the throttle 90 to the outlet port 12. Accordingly, the throttle 90 can maintain the control pressure operation valve 30 in an open state. Specifically, the throttle 90 can prevent the pressure of the refrigerant in the space S from suddenly rising and immediately closing the control pressure operation valve 30.
An expansion valve as a valve according to a third embodiment of the present invention will be described with reference to
As shown in
Further, the annular groove 56 is disposed on the axial left side in relation to the annular groove 57. These annular grooves 56 and 57 are disposed at the center in relation to both axial edges of the guide hole 10b of the valve housing 10 even when the valve 50 is closed and opened. That is, a substantially constant clearance is formed with the guide hole 10b at the position provided with the annular grooves 56 and 57 of the large-diameter portion 354 and in the vicinity thereof so as to allow a reciprocating movement.
When the refrigerant flows through a throttle 390 in the axial direction, a vortex of the refrigerant having a center in the circumferential direction is generated inside the annular grooves 56 and 57. Due to the vortex, the large-diameter portion 354 is aligned so that its axis matches the axis of the guide hole 10b. Accordingly, it is possible to reduce the driving force necessary for moving the valve body 51.
Further, since the vortex is generated inside the annular grooves 56 and 57, the refrigerant that tends to move relatively through the throttle 90 in the axial direction does not easily move. Therefore, the annular grooves 56 and 57 can prevent excessive leakage of the refrigerant from the space S to the outlet port 12.
Further, the annular grooves 56 and 57 of the large-diameter portion 354 face the guide hole 10b over the stroke range of the valve body 51. Therefore, the annular grooves 56 and 57 of the large-diameter portion 354 can stably align the valve body 51 and prevent excessive leakage of the refrigerant from the space S to the outlet port 12.
In addition, the number of the annular grooves may be one or three or more. Further, the annular groove may move toward the axial outside in relation to the guide hole 10b in the reciprocating movement.
Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these examples and is included in the present invention even if there are changes or additions within the scope of the present invention.
For example, in the above-described embodiments, an example has been described in which the valve opening degree is adjusted on the basis of the temperature difference of the refrigerant at the inlet side and the outlet side of the evaporator, but the present invention is not limited thereto. That is, the valve opening degree may be adjusted on the basis of the temperature or pressure of the refrigerant before or after passing through the condenser or the temperature or pressure of the refrigerant before or after passing through the evaporator or the configuration may be appropriately changed.
Further, in the above-described embodiments, an example has been described in which the expansion valve is formed such that the direction in which the refrigerant of the primary pressure is applied to the front end portion of the valve body is the same as the valve closing direction, but the present invention is not limited thereto. That is, the direction in which the refrigerant of the primary pressure is applied to the front end portion of the valve body may be the same as the valve opening direction. In such a case, the valve body may have a columnar shape extending with a constant cross-section. That is, the shape of the valve body may be appropriately changed.
Further, in the above-described embodiments, an example has been described in which the inlet port and the back surface side space of the valve body communicate with each other by the through-hole, but the present invention is not limited thereto. That is, the inlet port and the back surface side space of the valve body may communicate with each other by a large opening and a throttle member such as an orifice may be provided in the opening.
Further, in the above-described embodiments, an example has been described in which the control pressure operation valve is composed of the through-hole, the operation valve body, and the return spring, but the present invention is not limited thereto. That is, the inlet port and the space may communicate with each other when the center post is operated by the electromagnetic force of the solenoid and the inlet port and the space may communicate with each other when a member different from the center post is operated by the electromagnetic force of the solenoid.
Further, in the above-described embodiments, a configuration has been described in which the valve body also serves as the rod disposed to penetrate the coil of the solenoid, but the present invention is not limited thereto. That is, the valve body and the rod may be separate members.
Further, in the above-described embodiments, an example has been described in which the valve seat member including the valve seat and the valve housing including the guide hole are formed as separate members, but the present invention is not limited thereto. That is, the valve seat and the guide hole may be integrally formed on the inner peripheral surface of the valve housing.
Further, the guide portion is not limited to that formed in the valve housing and may be formed in, for example, a part of the insertion hole of the center post.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-132544 | Aug 2020 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2021/027770 | 7/27/2021 | WO |
