Differential pressure selector valve

Abstract

Provided is a differential pressure selector valve that can switch between flow paths at an appropriate timing.　The differential pressure selector valve comprises a low-pressure inflow port P3, a high-pressure outflow port P4, a first port P1, and a second port P2. Differential pressure on-off valves 2, 3 are respectively provided in a flow path between the low-pressure inflow port P3 and the first port P1 and in a flow path between the low-pressure inflow port P3 and the second port P2. The high-pressure outflow port P4 is communicated with the first port P1 and the second port P2, and differential pressure on-off valves 3, 4 are provided by which the flow path for outflow to the high-pressure outflow port P4 is switched by the pressures of the first port P1 and the second port P2.

Description

Differential pressure switching valve

[0001] The present invention relates to a differential pressure switching valve, for example, a differential pressure switching valve that switches a flow path through which a fluid flows.

[0002] In various industrial fields, fluid circuits are used in which a fluid supply source and a fluid load such as a fluid working device or a heat exchanger are connected by a flow path. Some of these fluid circuits are provided with a switching valve that switches the flow path of the working fluid, thereby realizing multiple modes for operating the fluid load using a single fluid circuit.

[0003] For example, the fluid circuit in Patent Document 1 is mainly composed of a compressor, a first switching valve, an outdoor heat exchanger, a second switching valve, a first pressure reducing device, a gas-liquid separator, a second pressure reducing device, and an indoor heat exchanger. The first switching valve is a four-way valve that switches the direction of refrigerant flow using external power depending on whether cooling or heating operation is to be performed.

[0004] The second switching valve is a four-way valve that switches the flow direction of the high-pressure refrigerant that flows into the second switching valve from the outdoor heat exchanger or the indoor heat exchanger by external power, passing it through the first pressure reducing device, the gas-liquid separator, and the second pressure reducing device in that order, and then flowing into the heat exchanger that it has not passed through.

[0005] As a result, the fluid circuit of Patent Document 1 can recover gas phase refrigerant, which contributes little to heat absorption, in the gas-liquid separator, regardless of whether cooling or heating operation is being performed, and can preferentially pass liquid phase refrigerant, which contributes to heat absorption, through the outdoor heat exchanger or the indoor heat exchanger, thereby improving cooling and heating capacity.

[0006] Japanese Patent Application Laid-Open No. 2001-241797 (pages 4 and 5, Figure 1)

[0007] In this way, with a fluid circuit equipped with a second switching valve such as that described in Patent Document 1, regardless of the operating mode, the fluid can be passed through a predetermined direction or first device, and then flowed into an appropriate direction or second device.

[0008] However, if the first and second four-way valves are switched simultaneously by an external power source to switch the operating mode during operation, the refrigerant immediately after passing through the second switching valve will be high-pressure, but will be connected to the heat exchanger to which low-pressure refrigerant had previously flowed. This causes the refrigerants in both flow paths to mix, making it impossible to maintain the pressures in both flow paths at a predetermined level, which could reduce the efficiency of the refrigeration cycle. To maintain the pressures in both flow paths at a predetermined level, it was necessary to individually control the timing of switching the first and second four-way valves in response to changes in the refrigerant pressure in each device.

[0009] The present invention has been made in view of the above-mentioned problems, and has an object to provide a differential pressure switching valve that can switch flow paths at appropriate timing.

[0010] In order to solve the above problem, the differential pressure switching valve of the present invention has a low-pressure inlet port, a high-pressure outlet port, a first port, and a second port, a differential pressure on-off valve is provided in each of a flow path between the low-pressure inlet port and the first port and a flow path between the low-pressure inlet port and the second port, and the high-pressure outlet port is connected to the first port and the second port, and a differential pressure on-off valve is provided that switches the flow path to the high-pressure outlet port depending on the pressure of the first port and the second port. In this way, the flow path is switched using the differential pressure due to changes in the pressure of the fluid at the first port and the pressure of the fluid at the second port, thereby eliminating the need for switching control using special power.

[0011] The differential pressure on-off valve provided in the flow path between the low-pressure inlet port and the first port and the differential pressure on-off valve provided in the flow path between the low-pressure inlet port and the second port may each be a check valve, which can simplify the structure.

[0012] The two check valves may be arranged in a direction that blocks inflow from the first port and the second port to the low-pressure inlet port, thereby enabling switching of the flow path that communicates with the low-pressure inlet port with a simple configuration.

[0013] The differential pressure on-off valve may be a check valve provided in a flow path between the high-pressure outlet port and the first port, and in a flow path between the high-pressure outlet port and the second port, respectively, which can simplify the structure.

[0014] The two check valves may be arranged in a direction that blocks flow from the high-pressure outlet port to the first port and the second port, thereby enabling switching of the flow path that communicates with the high-pressure outlet port with a simple configuration.

[0015] All of the differential pressure on-off valves may be disposed in a single housing, which allows for easy attachment and detachment to and from the fluid circuit.

[0016] Fig. 3 is a cross-sectional view of a differential pressure switching valve according to a first embodiment of the present invention. Fig. 4 is a cross-sectional view showing a state in which the differential pressure switching valve according to the first embodiment has switched to a flow path different from that in Fig. 1. Fig. 5 is a cross-sectional view of a differential pressure switching valve according to a second embodiment of the present invention. Fig. 6 is a cross-sectional view showing a state in which the differential pressure switching valve according to the second embodiment has switched to a flow path different from that in Fig. 3.

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A differential pressure switching valve according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0018] A differential pressure switching valve according to a first embodiment will be described with reference to Figures 1 and 2. In the following description, the top, bottom, left, and right of Figure 1 will be taken as the top, bottom, left, and right of the refrigerant switching valve.

[0019] 1, the differential pressure switching valve V1 of the present invention is a four-way valve provided in a fluid circuit for switching the flow direction between a first device Fs and a second device Ss in the fluid circuit. In this embodiment, a compressor (not shown) provided in the first device Fs increases the pressure of the fluid flowing through the fluid circuit, and a pressure reducer (not shown) provided in the second device Ss reduces the pressure of the fluid.

[0020] The differential pressure switching valve V1 is mainly composed of a housing 1, a first low-pressure side check valve 2, a second low-pressure side check valve 3, a first high-pressure side check valve 4, and a second high-pressure side check valve 5. Note that the check valves 2, 3, 4, and 5 are shown schematically in Figures 1 and 2.

[0021] The housing 1 is mainly composed of a base material 10 , a low-pressure side branch member 20 , a high-pressure side branch member 30 , a first side cover member 40 , and a second side cover member 50 .

[0022] The substrate 10 has a base 11 formed in a cylindrical shape extending in the left-right direction, four protrusions 12 , 13 , 14 , and 15 protruding radially outward from the base 11 , and a partition wall 16 .

[0023] The space inside the base 11 is divided into left and right spaces by a disk-shaped partition wall 16 that is hermetically welded and fixed inside the base 11. The space to the left of the partition wall 16 is a first side space R1, and the space to the right of the partition wall 16 is a second side space R2.

[0024] The partition wall 16 may be hermetically disposed relative to the base 11 by any suitable method other than welding, such as by using a sealing member, or by integrally molding the partition wall and the base. This also applies to the other components constituting the housing 1.

[0025] The protrusions 12, 13, 14, and 15 are cylindrical. Two of the protrusions 12 and 13 are provided on the upper side and are aligned in a straight line in the left-right direction. The other two protrusions 14 and 15 are provided on the lower side and are aligned in a straight line in the left-right direction.

[0026] The protrusions 12 and 14 are provided on the left side of the peripheral wall of the base material 10. The protrusions 13 and 15 are provided on the right side of the peripheral wall of the base material 10.

[0027] The flow path within the protrusion 12 communicates with the first side space R1. A first low-pressure side check valve 2 is provided in the flow path within the protrusion 12. The first low-pressure side check valve 2 is disposed in a direction that prevents fluid from flowing from the first side space R1 into a low-pressure inlet port P3, which will be described later.

[0028] The flow path within the protrusion 13 is connected to the second side space R2. A second low-pressure side check valve 3 is provided in the flow path within the protrusion 13. The second low-pressure side check valve 3 is disposed in a direction that prevents fluid from flowing from the second side space R2 into the low-pressure inflow port P3.

[0029] The flow path within the protrusion 14 is in communication with the first side space R1. A first high-pressure side check valve 4 is provided in the flow path within the protrusion 14. The first high-pressure side check valve 4 is positioned in a direction that prevents fluid from flowing into the first side space R1 from a high-pressure outflow port P4, which will be described later.

[0030] The flow path within the protrusion 15 is connected to the second side space R2. A second high-pressure side check valve 5 is provided in the flow path within the protrusion 15. The second high-pressure side check valve 5 is disposed in a direction that prevents fluid from flowing into the second side space R2 from a high-pressure outflow port P4, which will be described later.

[0031] The low-pressure side branch member 20 has a neck portion 21 , a first side arm portion 22 , and a second side arm portion 23 , and is formed in an upside-down Y shape.

[0032] The neck 21 is formed in a cylindrical shape extending in the vertical direction. The lower end of the space within the neck 21 is connected to a space extending in the left-right direction. That is, the flow path within the neck 21 is connected to the flow path within the first side arm 22 and the flow path within the second side arm 23.

[0033] The flow path within the neck 21 is also connected to a low-pressure flow path S1 through which the low-pressure fluid decompressed by the second device Ss flows toward the neck 21. That is, in the flow path within the neck 21, the opening that communicates with the low-pressure flow path S1 is a low-pressure inlet port P3 through which the low-pressure fluid flows.

[0034] The first side arm 22 is formed in a cylindrical shape that extends leftward from the lower left end of the neck 21, then curves downward by approximately 90 degrees and extends downward. The first side arm 22 is fixed to the protruding portion 12 of the base material 10 by welding in a hermetically sealed manner. The internal flow path of the first side arm 22 is connected to the internal flow path of the protruding portion 12.

[0035] The second side arm 23 is formed in a cylindrical shape that extends rightward from the right lower end of the neck 21, then curves downward by approximately 90 degrees and extends downward. The second side arm 23 is fixed to the protruding portion 13 of the base material 10 by welding in a hermetically sealed manner. The internal flow path of the second side arm 23 communicates with the internal flow path of the protruding portion 13.

[0036] The high-pressure side branch member 30 has a neck portion 31 , a first side arm portion 32 , and a second side arm portion 33 , and is formed in a Y shape.

[0037] The neck 31 is formed in a cylindrical shape extending in the vertical direction. The upper end of the space within the neck 31 communicates with the space extending in the left-right direction. The flow path within the neck 31 communicates with the flow path within the first side arm 32 and the flow path within the second side arm 33.

[0038] The flow path in the neck 31 is connected to a high-pressure flow path S2 through which the high-pressure fluid pressurized by the first device Fs flows toward the second device Ss. That is, the opening in the flow path in the neck 31 that is connected to the high-pressure flow path S2 is a high-pressure outflow port P4 through which the high-pressure fluid flows out.

[0039] The first side arm 32 is formed in a cylindrical shape that extends leftward from the upper left end of the neck 31, then curves upward by approximately 90 degrees and extends upward. The first side arm 32 is fixed by welding to the protruding portion 14 of the base material 10 in a hermetically sealed manner. The internal flow path of the first side arm 32 is connected to the internal flow path of the protruding portion 14.

[0040] The second side arm 33 is formed in a cylindrical shape that extends rightward from the upper right end of the neck 31, then curves upward by approximately 90 degrees and extends upward. The second side arm 33 is fixed by welding to the protruding portion 15 of the base material 10 in a hermetically sealed manner. The internal flow path of the second side arm 33 communicates with the internal flow path of the protruding portion 15.

[0041] The first side cover member 40 is formed in a sidewalled cylindrical shape that is open on the axial right side and has a sidewall on the axial left side. The first side cover member 40 is fixed by welding to the base 11 of the substrate 10 in a hermetically sealed manner. As a result, the space within the first side cover member 40, together with the space on the left side within the base 11, constitutes a first side space R1.

[0042] The first side cover member 40 has a cylindrical extension 41 extending axially leftward from the center of the side wall. The flow path within the extension 41 communicates with the first side space R1.

[0043] The flow path within the extension portion 41 is connected to a first flow path F1 extending from the first device Fs. That is, the opening in the flow path within the extension portion 41 that is connected to the first flow path F1 is a first port P1 through which a high-pressure fluid flows in (see FIG. 1) or a low-pressure fluid flows out (see FIG. 2), as will be described in detail later.

[0044] The second side cover member 50 is formed in a sidewalled cylindrical shape that is open on the axial left side and has a sidewall on the axial right side. The second side cover member 50 is fixed by welding to the base 11 of the substrate 10 in a hermetically sealed manner. As a result, the space within the second side cover member 50, together with the space on the right side within the base 11, constitutes the second side space R2.

[0045] The second side cover member 50 has a cylindrical extension 51 extending axially rightward from the center of the side wall. The flow path within the extension 51 communicates with the second side space R2.

[0046] The flow path within the extension portion 51 is connected to a second flow path F2 extending from the first device Fs. That is, the opening in the flow path within the extension portion 51 that is connected to the second flow path F2 is a second port P2 through which a low-pressure fluid flows out (see FIG. 1) or a high-pressure fluid flows in (see FIG. 2), as will be described in detail later.

[0047] Next, the switching of the flow paths in the differential pressure switching valve V1 will be described. The switching between sending high-pressure fluid to the first flow path F1 and receiving low-pressure fluid from the second flow path F2, or sending high-pressure fluid to the second flow path F2 and drawing in low-pressure fluid from the first flow path F1, is controlled by the first device Fs.

[0048] First, referring to Fig. 1, a state in which high-pressure fluid flows into the first port P1 and low-pressure fluid flows out of the second port P2 will be described. As indicated by the thick arrow in Fig. 1, the high-pressure fluid flows into the first side space R1 through the first port P1.

[0049] The high-pressure fluid that has flowed into the first side space R1 passes through the first high-pressure side check valve 4 and flows into the flow path inside the high-pressure side branch member 30. In addition, the high-pressure fluid that has flowed into the first side space R1 is prevented from flowing into the flow path inside the low-pressure side branch member 20 by the first low-pressure side check valve 2.

[0050] The high-pressure fluid that has flowed into the flow path within the high-pressure side branch member 30 flows out from the high-pressure outlet port P4 to the high-pressure flow path S2. In addition, the high-pressure fluid that has flowed into the flow path within the high-pressure side branch member 30 is prevented from flowing into the second side space R2 by the second high-pressure side check valve 5.

[0051] These prevent the high-pressure fluid that has flowed into the first side space R1 from being mixed with the low-pressure fluid.

[0052] As shown by the thin arrow in FIG. 1, the low-pressure fluid flows into the flow path inside the low-pressure branch member 20 through the low-pressure inlet port P3.

[0053] The low-pressure fluid that has flowed into the flow path within the low-pressure side branch member 20 passes through the second low-pressure side check valve 3 and flows into the second side space R2. The first low-pressure side check valve 2 is closed by the pressure in the first side space R1 into which the high-pressure fluid is flowing.

[0054] The low-pressure fluid that has flowed into the second side space R2 flows out from the second port P2 to the second flow path F2. The second high-pressure side check valve 5 is closed by the pressure in the flow path within the second side arm 33 into which the high-pressure fluid is flowing.

[0055] These prevent the low-pressure fluid that has flowed into the second side space R2 from being mixed with the high-pressure fluid.

[0056] Immediately after the transition from the state of Figure 1 to the state of Figure 2, that is, immediately after the flow path on the first device Fs side is switched so that high-pressure fluid is sent from the first device Fs to the second flow path F2 and low-pressure fluid is sucked into the first device Fs from the first flow path F1 under control of the first device Fs side, the pressure of the first flow path F1, into which high-pressure fluid had been flowing until just before, begins to decrease.

[0057] The fluid in the first side space R1 flows out into the first flow path F1 through the first port P1 as indicated by the thin arrow, and the pressure in the first side space R1 also decreases.

[0058] Even if the pressure in the first side space R1 decreases and the pressure in the flow path within the high-pressure side branch member 30 increases, the fluid in the flow path within the high-pressure side branch member 30 is prevented from flowing into the first side space R1 by the first high-pressure side check valve 4. This makes it possible to efficiently reduce the pressure in the first side space R1.

[0059] The first high-pressure-side check valve 4 is closed by the pressure in the flow path inside the high-pressure-side branch member 30. This prevents the fluid in the first side space R1, which has a lower pressure than the high-pressure fluid, from flowing into the flow path inside the high-pressure-side branch member 30.

[0060] Furthermore, if the pressure in the first side space R1 exceeds the pressure in the flow path inside the low-pressure side branch member 20, the first low-pressure side check valve 2 remains closed. This makes it possible to more efficiently reduce the pressure in the first side space R1.

[0061] In addition, a fluid with a pressure higher than the low-pressure fluid is prevented from flowing into the flow path inside the low-pressure side branch member 20.

[0062] When the pressure in the first side space R1 falls below the pressure in the flow path inside the low-pressure side branch member 20, the first low-pressure side check valve 2 opens, and the low-pressure fluid that had been flowing into the flow path inside the low-pressure side branch member 20 passes through the first low-pressure side check valve 2 and flows into the first side space R1, as shown by the thin arrow in Figure 2. At this time, the difference between the pressure in the flow path inside the low-pressure side branch member 20 and the pressure in the first side space R1 is almost zero.

[0063] On the other hand, the high-pressure fluid sent from the first device Fs to the second flow path F2 flows into the second side space R2 through the second port P2, as shown by the thick arrow in Figure 2. Accordingly, the pressure in the second side space R2 also increases.

[0064] When the pressure in the second side space R2 increases and becomes higher than the pressure in the flow path inside the low-pressure side branch member 20, the second low-pressure side check valve 3 is closed. This prevents the fluid in the flow path inside the low-pressure side branch member 20 from flowing into the second side space R2, so that the pressure in the second side space R2 can be increased efficiently.

[0065] In addition, the fluid in the second side space R2, which is at a pressure higher than the low-pressure fluid, is prevented by the second low-pressure side check valve 3 from flowing into the flow path inside the low-pressure side branch member 20.

[0066] Furthermore, if the pressure in the second side space R2 is lower than the pressure in the flow path inside the high-pressure side branch member 30, the second high-pressure side check valve 5 remains closed. This makes it possible to increase the pressure in the second side space R2 more efficiently.

[0067] In addition, fluid with a pressure lower than that of the high-pressure fluid is prevented from flowing into the flow path inside the high-pressure side branch member 30.

[0068] When the pressure in the second side space R2 becomes equal to or greater than the pressure in the flow path within the high-pressure side branch member 30, the second high-pressure side check valve 5 opens, and the high-pressure fluid that had been flowing into the second side space R2 passes through the second high-pressure side check valve 5, as shown by the thick arrow, and flows into the flow path within the high-pressure side branch member 30. At this time, the difference between the pressure in the second side space R2 and the pressure in the flow path within the high-pressure side branch member 30 is almost zero.

[0069] As described above, immediately after the differential pressure switching valve V1 transitions from the state shown in FIG. 1 to the state shown in FIG. 2, the differential pressure switching valve V1 can perform switching control while preventing fluids of different pressures from being mixed together, without using any special power.

[0070] The above-mentioned switching control is also the same immediately after transitioning from the state of Figure 2 to the state of Figure 1, i.e., when the flow path on the first device Fs side is switched so that high-pressure fluid is sent from the first device Fs to the first flow path F1 and low-pressure fluid is sucked into the first device Fs from the second flow path F2.

[0071] In other words, immediately after the flow path on the first device Fs side is switched so that high-pressure fluid is sent from the first device Fs to the first flow path F1 and low-pressure fluid is drawn into the first device Fs from the second flow path F2, the differential pressure switching valve V1 closes communication between the first port P1 and the high-pressure outlet port P4 if the pressure in the first side space R1 is lower than the pressure in the flow path within the high-pressure side branch member 30. Thereafter, if the pressure in the first side space R1 becomes equal to or higher than the pressure in the flow path within the high-pressure side branch member 30, the differential pressure switching valve V1 closes communication between the first port P1 and the high-pressure outlet port P4.

[0072] Furthermore, immediately after the flow path on the first device Fs side is switched so that high-pressure fluid is sent from the first device Fs to the first flow path F1 and low-pressure fluid is drawn into the first device Fs from the second flow path F2, if the pressure in the second side space R2 exceeds the pressure in the flow path within the low-pressure side branch member 20, the differential pressure switching valve V1 closes communication between the second port P2 and the low-pressure inlet port P3. Thereafter, if the pressure in the second side space R2 falls to or below the pressure in the flow path within the low-pressure side branch member 20, the differential pressure switching valve V1 opens communication between the second port P2 and the low-pressure inlet port P3.

[0073] As described above, the differential pressure switching valve V1 can perform switching control while preventing fluids of different pressures from being mixed together, without using any special power, even immediately after transitioning from the state shown in FIG. 2 to the state shown in FIG. 1.

[0074] As described above, the differential pressure switching valve V1 of this embodiment has a simple structure because the differential pressure on-off valve provided in the flow path between the low-pressure inlet port P3 and the first port P1 is the first low-pressure side check valve 2, and the differential pressure on-off valve provided in the flow path between the low-pressure inlet port P3 and the second port P2 is the second low-pressure side check valve 3.

[0075] Furthermore, the first low-pressure side check valve 2 is disposed in a direction that blocks the flow of fluid from the first port P1 to the low-pressure inlet port P3. The second low-pressure side check valve 3 is disposed in a direction that blocks the flow of fluid from the second port P2 to the low-pressure inlet port P3. As a result, the differential pressure switching valve V1 can switch the flow path that communicates with the low-pressure inlet port P3 with a simple configuration.

[0076] Furthermore, the differential pressure switching valve V1 has a simple structure because the differential pressure on-off valve provided in the flow path between the high-pressure outlet port P4 and the first port P1 is the first high-pressure side check valve 4, and the differential pressure on-off valve provided in the flow path between the high-pressure outlet port P4 and the second port P2 is the second high-pressure side check valve 5.

[0077] Furthermore, the first high-pressure side check valve 4 is disposed in a direction that blocks fluid from flowing from the high-pressure outlet port P4 to the first port P1. The second high-pressure side check valve 5 is disposed in a direction that blocks fluid from flowing from the high-pressure outlet port P4 to the second port P2. This makes it possible to switch the flow path that communicates with the high-pressure outlet port P4 with a simple configuration.

[0078] In addition, the differential pressure switching valve V1 can be easily attached to and detached from the fluid circuit because all of the check valves 2, 3, 4, and 5 are arranged in one housing 1. Furthermore, the structure is simple because the partition wall 16 is provided on the base material 10 and the four check valves 2, 3, 4, and 5 are arranged therein.

[0079] The first side space R1 and the second side space R2 are separated by a single partition wall 16. In other words, pressures higher than atmospheric pressure act on the partition wall 16 from both the first side space R1 and the second side space R2. The pressure difference acting on both sides of the partition wall 16 is smaller than the pressure difference acting on the peripheral wall of the substrate 10 that faces the atmosphere. This allows the thickness of the partition wall 16 required to withstand fluid pressure to be thinner than the thickness of the portion that faces atmospheric pressure.

[0080] Furthermore, since the fluid flowing through the first device Fs and the fluid flowing through the second device Ss are the same type of fluid, they can be mixed as long as the pressure is approximately constant, which simplifies the switching control of the differential pressure switching valve V1.

[0081] Next, a differential pressure switching valve according to a second embodiment will be described with reference to Figures 3 and 4. Note that a description of the same configuration as in the previous embodiment will be omitted.

[0082] As shown in FIG. 3, the differential pressure switching valve V2 of this second embodiment differs from the differential pressure switching valve V1 of the previous embodiment in that the check valves 4 and 5 are omitted, while a differential pressure opening / closing valve 104 is provided in the high-pressure side branch member 130.

[0083] The high-pressure side branch member 130 has a neck portion 131, a first side arm portion 132, a second side arm portion 133, an expanded diameter portion 134, and a ball 105. The expanded diameter portion 134 and the ball 105 constitute the differential pressure on-off valve 104.

[0084] The expanded diameter portion 134 is formed in a cylindrical shape with side walls extending in the left-right direction, and its flow path cross-sectional area is larger than the flow path cross-sectional area of ​​each of the neck portion 131, the first side arm portion 132, and the second side arm portion 133.

[0085] The neck portion 131 is cylindrical and protrudes radially outward from the axial center of the peripheral wall of the expanded diameter portion 134. The first side arm portion 132 is cylindrical and extends leftward from the radial center of the left wall of the expanded diameter portion 134, then curves upward at approximately 90 degrees and extends upward. The second side arm portion 133 is cylindrical and extends rightward from the radial center of the right wall of the expanded diameter portion 134, then curves upward at approximately 90 degrees and extends upward.

[0086] A ball 105 is disposed in the flow path within the expanded diameter portion 134. The diameter of the ball 105 is slightly smaller than the diameter of the flow path within the expanded diameter portion 134 and is larger than the cross-sectional area of ​​the flow path of each of the neck portion 131, the first side arm portion 132, and the second side arm portion 133.

[0087] With this configuration, immediately after the flow path on the first device Fs side is switched so that high-pressure fluid is sent from the first device Fs to the first flow path F1 and low-pressure fluid is sucked into the first device Fs through the second flow path F2 under control of the first device Fs side, the pressure in the first side space R1 rises while the decreasing pressure in the second side space R2 is greater, so as shown in Figure 4, the ball 105 blocks the space between the flow path inside the first side arm portion 132 and the flow path inside the neck portion 131.

[0088] When the rising pressure in the first side space R1 exceeds the falling pressure in the second side space R2, the ball 105 moves axially to the right, and as shown in Figure 3, the passage between the first side arm portion 132 and the passage between the neck portion 131 is opened, and the passage between the second side arm portion 133 and the passage between the neck portion 131 is closed.

[0089] Similarly, immediately after the flow path on the first device Fs side is switched so that high-pressure fluid is sent from the first device Fs to the second flow path F2 and low-pressure fluid is sucked from the first flow path F1 into the first device Fs, the pressure in the second side space R2 rises, but the decreasing pressure in the first side space R1 is greater, so as shown in Figure 3, the ball 105 blocks the space between the second side arm portion 133 and the flow path within the neck portion 131.

[0090] When the rising pressure in the second side space R2 exceeds the falling pressure in the first side space R1, the ball 105 moves axially to the left, and as shown in Figure 4, the flow path inside the second side arm 133 and the flow path inside the neck 131 are opened, and the flow path inside the first side arm 132 and the flow path inside the neck 131 are closed.

[0091] As described above, the differential pressure switching valve V2 can perform switching control without using any special power while preventing fluids with different pressures from being mixed together.

[0092] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention also includes modifications and additions that do not deviate from the gist of the present invention.

[0093] For example, in the first and second embodiments, the differential pressure switching valve is described as being provided between a first device in which the fluid pressure is increased and a second device in which the fluid pressure is decreased, but this is not limited to this, and the differential pressure switching valve may be provided in a third device provided between the first device and the second device, and the configuration of the fluid circuit may be changed as appropriate.

[0094] In addition, in the first and second embodiments, all of the differential pressure on-off valves are described as being arranged in one housing, but this is not limited to this, and they may be arranged distributed across multiple housings.

[0095] In addition, in the first and second embodiments, the space within the housing is described as being divided by one partition wall, but this is not limited thereto, and the space within the housing may be divided by two or more partition walls. Furthermore, when two or more partition walls are provided, it is preferable to prevent heat exchange between the fluid flowing into the first side space and the fluid flowing into the second side space by filling the space between the partition walls with a heat insulating material, creating a vacuum, or the like.

[0096] REFERENCE SIGNS LIST 1 Housing 2 First low-pressure side check valve (differential pressure on / off valve) 3 Second low-pressure side check valve (differential pressure on / off valve) 4 First high-pressure side check valve (differential pressure on / off valve) 5 Second high-pressure side check valve (differential pressure on / off valve) 16 Partition wall 104 Differential pressure on / off valve F1 First flow path F2 Second flow path Fs First device P1 First port P2 Second port P3 Low-pressure inlet port P4 High-pressure outlet port R1 First side space R2 Second side space S1 Low-pressure flow path S2 High-pressure flow path Ss Second device V1, V2 Differential pressure switching valve

Claims

1. A differential pressure switching valve having a low pressure inlet port, a high pressure outlet port, a first port, and a second port, wherein a differential pressure on-off valve is provided in each of the flow paths between the low pressure inlet port and the first port and between the low pressure inlet port and the second port, and the high pressure outlet port is connected to the first port and the second port, and a differential pressure on-off valve is provided which switches the flow path to the high pressure outlet port depending on the pressure of the first port and the second port.

2. A differential pressure switching valve as described in claim 1, wherein the differential pressure on-off valve provided in the flow path between the low pressure inlet port and the first port, and the differential pressure on-off valve provided in the flow path between the low pressure inlet port and the second port are each a check valve.

3. A differential pressure switching valve as set forth in claim 2, wherein the two check valves are arranged in a direction that blocks inflow from the first port and the second port to the low pressure inflow port.

4. A differential pressure switching valve as described in claim 1, wherein the differential pressure on-off valve is a check valve provided in the flow path between the high pressure outlet port and the first port, and in the flow path between the high pressure outlet port and the second port.

5. A differential pressure switching valve as set forth in claim 4, wherein the two check valves are arranged in a direction that blocks flow from the high pressure outlet port to the first port and the second port.

6. A differential pressure switching valve according to any one of claims 1 to 5, wherein all of said differential pressure on-off valves are disposed within a single housing.

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