Flow path switching system

Abstract

A flow path switching system is provided with: a flow path switching valve unit; and a pump that conveys a fluid to the flow path switching valve unit. The flow path switching valve portion includes an introduction flow path into which the fluid conveyed by the pump is introduced, a first discharge flow path and a second discharge flow path which branch from the introduction flow path and discharge the fluid, a movable wall chamber, a movable wall disposed in the movable wall chamber, and a drive shaft connected to the movable wall. And a valve body provided on the drive shaft, the valve body opening and closing the first lead-out flow path and the second lead-out flow path by operating the movable wall to drive the drive shaft, and switching the flow paths, the flow path switching system being provided with: a first communication path that communicates with the first lead-out flow path and the second lead-out flow path, and communicates with the first lead-out flow path and the second lead-out flow path; a valve that communicates the movable wall chamber with an upstream-side flow path of the pump; a second communication path that communicates the movable wall chamber with a downstream flow path of the pump; and a communication state switching valve that switches a communication state between the first communication path and the second communication path.

Description

Technical Field

[0001] This disclosure relates to a flow path switching system for switching the flow path of a fluid (e.g., cooling water). Background Technology

[0002] Patent document 1 discloses a flow path structure in which a fluid (heat medium) transported by a pump is supplied to a heater core while being controlled by a main valve.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-82950 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] Patent document 1 does not disclose any information regarding the pump efficiency (i.e., the ratio of pump output to input). Assuming the main valve is configured as a three-way valve switching between two flow paths, the pump efficiency may decrease depending on which flow path is switched.

[0008] Therefore, this disclosure was made to solve the above-mentioned problems, and its purpose is to provide a flow path switching system that can suppress the decrease in pump efficiency and use the pressure before and after the pump to switch the flow path.

[0009] Solution for solving the problem

[0010] To address the aforementioned issues, this disclosure provides a flow path switching system comprising: a flow path switching valve section; and a pump that supplies fluid to the flow path switching valve section. The flow path switching valve section includes an inlet flow path for introducing the fluid supplied by the pump, a first outlet flow path and a second outlet flow path branching from the inlet flow path and leading out the fluid, a movable chamber, a movable wall disposed within the movable chamber, a drive shaft connected to the movable wall, and a valve core disposed on the drive shaft. The drive shaft is driven by actuating the movable wall, thereby switching the flow path by opening and closing the first outlet flow path and the second outlet flow path using the valve core. The flow path switching system is characterized by having: a first connecting path connecting the movable chamber to an upstream flow path of the pump; a second connecting path connecting the movable chamber to a downstream flow path of the pump; and a connection state switching valve that switches the connection state of the first connecting path and the second connecting path.

[0011] According to this technical solution, the connection states of the first and second connecting paths are switched by a connection state switching valve (i.e., the connection states between the movable wall chamber and the upstream and downstream flow paths of the pump achieved by the first and second connecting paths), thereby enabling the movable wall to move freely using the pressure before and after the pump (i.e., the pressure on the upstream and downstream sides). Furthermore, the movable wall is moved by the pressure before and after the pump, which drives the drive shaft, thereby allowing the flow paths to be switched by opening and closing the first and second outlet flow paths using the valve core.

[0012] At this point, even with no fluid flow in the first and second connecting paths, the pump's pressure before and after the flow path can be transmitted to the movable chamber. Therefore, it is possible to suppress the decrease in pump efficiency of the pump supplying fluid to the flow path switching valve section. Thus, it is possible to suppress the decrease in pump efficiency and utilize the pump's pressure before and after the flow path to switch.

[0013] In the above technical solution, preferably, the movable wall chamber includes a back pressure chamber separated by the movable wall, and the connection state switching valve is switched to either a state in which the back pressure chamber is connected to the upstream flow path of the pump via the first connection path, or a state in which the back pressure chamber is connected to the downstream flow path of the pump via the second connection path.

[0014] According to this technical solution, the flow path can be switched using the pressure before and after the pump through a simple structure. Therefore, the manufacturing cost of the flow path switching system can be reduced.

[0015] In the above technical solution, preferably, the movable wall chamber includes a back pressure chamber and an intermediate chamber separated from the back pressure chamber by the movable wall. The first connecting passage is a passage that connects the back pressure chamber to the upstream flow path of the pump, and the second connecting passage is a passage that connects the intermediate chamber to the downstream flow path of the pump. An intermediate passage is provided as a passage for connecting the first connecting passage and the second connecting passage. The connection state switching valve switches to either a state in which the back pressure chamber and the intermediate chamber are connected to the upstream flow path of the pump via the intermediate passage connecting the first connecting passage and the second connecting passage, or a state in which the back pressure chamber is connected to the upstream flow path of the pump via the first connecting passage and the intermediate chamber is connected to the downstream flow path of the pump via the second connecting passage.

[0016] According to this technical solution, in addition to the back pressure chamber, the pressure of the intermediate chamber can also be adjusted, which can improve the responsiveness of the valve core. Therefore, it can improve the responsiveness of flow path switching.

[0017] In the above technical solution, preferably, the movable wall chamber includes a back pressure chamber and an intermediate chamber separated from the back pressure chamber by the movable wall. The first connecting passage is a passage that connects the back pressure chamber to the upstream flow path of the pump, and the second connecting passage is a passage that connects the intermediate chamber to the downstream flow path of the pump. An intermediate passage is provided as a passage that connects the first connecting passage and the second connecting passage. The connection state switching valve switches to any one of the following states: a state in which the back pressure chamber and the intermediate chamber are connected to both the upstream flow path and the downstream flow path of the pump via the intermediate passage connecting the first connecting passage and the second connecting passage; and a state in which the back pressure chamber is connected to the upstream flow path of the pump via the first connecting passage and the intermediate chamber is connected to the downstream flow path of the pump via the second connecting passage.

[0018] According to this technical solution, in addition to the back pressure chamber, the pressure of the intermediate chamber can also be adjusted, which can improve the responsiveness of the valve core. Therefore, it can improve the responsiveness of flow path switching.

[0019] In the above technical solution, it is preferred that the movable wall is a diaphragm.

[0020] According to this technical solution, the manufacturing cost of the flow path switching system can be suppressed because a relatively inexpensive diaphragm is used.

[0021] In the above technical solution, preferably, the flow path switching system is a flow path switching device that is integrally formed by the flow path switching valve and the pump.

[0022] According to this technical solution, by configuring the pump as the drive unit of the flow path switching valve, it is possible to design a compact and low-cost flow path switching device.

[0023] In the above technical solution, it is preferred that the flow path switching system is installed in the flow path of the cooling water of the electric vehicle.

[0024] According to this technical solution, the flow of cooling water in electric vehicles can be efficiently controlled through a flow path switching system. Therefore, it can improve the energy efficiency of electric vehicles and contribute to carbon neutrality.

[0025] The effects of the invention

[0026] The flow path switching system disclosed herein can suppress the reduction of pump efficiency and switch the flow path by utilizing the pressure before and after the pump. Attached Figure Description

[0027] Figure 1 This is a front view of the flow path switching device of the first embodiment.

[0028] Figure 2This is a perspective view of the flow path switching device according to the first embodiment.

[0029] Figure 3 This is a cross-sectional view (partial appearance view) of the flow path switching device of the first embodiment.

[0030] Figure 4 This is a diagram showing the upward flow holding state (the state of holding the upward flow) in the first embodiment.

[0031] Figure 5 This is a diagram showing the switching state of the downward flow in the first embodiment (the state of switching from upward flow to downward flow).

[0032] Figure 6 This is a diagram showing the downward flow holding state (holding the downward flow state) in the first embodiment.

[0033] Figure 7 This is a diagram showing the switching state of the upward flow in the first embodiment (the state of switching from downward flow to upward flow).

[0034] Figure 8 This is a diagram showing the upward flow holding state in the first embodiment of the second implementation.

[0035] Figure 9 This is a diagram showing the switching state of the downward flow switching in the first embodiment of the second implementation.

[0036] Figure 10 This is a diagram showing the downward flow holding state in the first embodiment of the second implementation.

[0037] Figure 11 This is a diagram showing the switching state of the upward flow switching in the first embodiment of the second implementation.

[0038] Figure 12 This is a diagram showing the upward flow holding state in the second embodiment of the second implementation.

[0039] Figure 13 This is a diagram showing the initial state of the downward flow switching in the second embodiment of the second implementation (the state at which the flow switches from upward to downward).

[0040] Figure 14 This is a diagram showing the valve-opening state (the state in which the valve is to be opened in order to switch from upward flow to downward flow) in the second embodiment of the second implementation.

[0041] Figure 15This is a diagram showing the intermediate state of the downward flow switching in the second embodiment of the second implementation (the intermediate state of switching from upward flow to downward flow).

[0042] Figure 16 This is a diagram showing the downward flow holding state in the second embodiment of the second implementation.

[0043] Figure 17 This is a diagram showing the initial state of the upward flow switching in the second embodiment of the second implementation (the state where the flow switching from downward to upward begins).

[0044] Figure 18 This is a diagram showing the valve-opening state (the state in which the valve is to be opened in order to switch from downward flow to upward flow) in the second embodiment of the second implementation.

[0045] Figure 19 This is a diagram showing the intermediate state of the upward flow switching in the second embodiment of the second implementation (the intermediate state of switching from downward flow to upward flow). Detailed Implementation

[0046] An embodiment of the flow path switching system of this disclosure will be described. In the following description, a flow path switching device, which is an example of an embodiment of the flow path switching system of this disclosure, will be described.

[0047] <First Implementation Method>

[0048] First, the flow path switching device 1 of the first embodiment will be described.

[0049] The flow path switching device 1 is, for example, a device installed in the flow path of cooling water in an electric vehicle (not shown) and controlling the flow rate of the cooling water. Furthermore, "electric vehicle" refers to a vehicle driven by electricity from a secondary battery, such as an electric car or a hybrid vehicle. Additionally, cooling water is an example of the "fluid" disclosed herein.

[0050] (Structure of the flow path switching device)

[0051] like Figures 1-3 As shown, the flow path switching device 1 includes a flow path switching valve section 11, a pump 12, and a control section 13, which are integrally formed into one device. Alternatively, the control section 13 can be provided independently of the flow path switching device 1. Furthermore, for ease of explanation, the control section 13 is only shown in the diagram. Figure 1 As shown in, Figure 2 The following attached figures are omitted.

[0052] The flow path switching valve section 11 is a valve section for switching flow paths. The flow path switching valve section 11 has an inlet flow path 21 for introducing cooling water supplied by the pump 12, and a first outlet flow path 22-1 and a second outlet flow path 22-2 that branch off from the inlet flow path 21 and outlet the cooling water.

[0053] In addition, the flow path switching valve section 11 includes a diaphragm chamber 23, a diaphragm 24 disposed in the diaphragm chamber 23, a drive shaft 25 connected to the diaphragm 24, a valve core 26 disposed at one end of the drive shaft 25, a first valve seat 27-1, and a second valve seat 27-2.

[0054] The diaphragm chamber 23 includes a back pressure chamber 31 separated by a diaphragm 24. Furthermore, the back pressure chamber 31 is provided with a force that directs downward movement of the diaphragm 24 ( Figure 4 The spring 33 applies force from below. In this embodiment, the portion of the diaphragm chamber 23 that is opposite to the back pressure chamber 31 via the diaphragm 24 (corresponding to the portion of the intermediate chamber 32 described later) is open to the first outlet flow path 22-1. Furthermore, the diaphragm chamber 23, the back pressure chamber 31, and the intermediate chamber 32 described later are examples of the "movable wall chamber" of this disclosure, and the diaphragm 24 is an example of the "movable wall" of this disclosure.

[0055] Pump 12 is a device that supplies cooling water to the flow path switching valve section 11.

[0056] The control unit 13 is a device that controls the flow path switching device 1. This control unit 13 controls, for example, the pump 12, the pilot valve 51 (described later), and the pilot valve 91.

[0057] In this embodiment, such as Figures 1-4 As shown, the flow path switching device 1 has a first connecting path 41, a second connecting path 42, and a pilot valve 51.

[0058] The first connecting passage 41 is formed by the pressure transmission passage 60 and the first branch passage 61, and is a passage that enables the back pressure chamber 31 to connect with the upstream flow passage 71 of the pump. In addition, the upstream flow passage 71 of the pump is a flow passage located upstream of the pump 12 in the flow direction of the cooling water, and is an example of the "upstream flow passage of the pump" of this disclosure.

[0059] The second connecting passage 42 is formed by the pressure transmission passage 60 and the second branch passage 62, and is a passage that enables the back pressure chamber 31 to connect with the downstream flow passage 72 of the pump. In addition, the downstream flow passage 72 of the pump is a flow passage located downstream of the pump 12 in the flow direction of the cooling water, and is an example of the "downstream flow passage of the pump" of this disclosure.

[0060] Pilot valve 51 is a valve that switches the connection state of the first connection path 41 and the second connection path 42. That is, pilot valve 51 can be switched to either a state that connects the pressure transmission path 60 to the first branch path 61 or a state that connects the pressure transmission path 60 to the second branch path 62. Furthermore, pilot valve 51 is an example of the "connection state switching valve" of this disclosure.

[0061] (Function of the flow path switching device)

[0062] The flow path switching device 1 with this structure drives the drive shaft 25 by actuating the diaphragm 24, thereby switching the flow path by opening and closing the first outlet flow path 22-1 and the second outlet flow path 22-2 using the valve core 26. Specifically, the flow path switching device 1 adjusts the pressure of the back pressure chamber 31 by utilizing the pressure before and after the pump 12, thereby actuating the diaphragm 24.

[0063] In addition, the pilot valve 51 can be switched to either a state in which the back pressure chamber 31 is connected to the upstream flow path 71 of the pump via the first connecting path 41, or a state in which the back pressure chamber 31 is connected to the downstream flow path 72 of the pump via the second connecting path 42.

[0064] Therefore, the following explains the specific switching of flow paths. First, as... Figure 4 As shown, the pilot valve 51 is in the closed state, the pressure transmission passage 60 is disconnected from the first branch passage 61, and on the other hand, the pressure transmission passage 60 is connected to the second branch passage 62.

[0065] Thus, the back pressure chamber 31 is connected to the downstream flow path 72 of the pump via the second connecting passage 42. Therefore, even when there is no cooling water flow in the second connecting passage 42, the pressure in the downstream flow path 72 is transmitted to the back pressure chamber 31. Additionally, the force of the spring 33 acts downwards on the diaphragm 24.

[0066] Furthermore, the valve core 26 abuts against the second valve seat 27-2, and the valve hole of the first valve seat 27-1 (i.e., the hole provided on the inner side of the first valve seat 27-1) is open. Therefore, a flow path is formed by the inlet flow path 21 and the first outlet flow path 22-1, and cooling water flows from the inlet flow path 21 to the first outlet flow path 22-1. Thus, the pressure of the cooling water flowing from the inlet flow path 21 to the first outlet flow path 22-1 acts downward (i.e., in the direction of the second valve seat 27-2) on the valve core 26. In this way, the flow path switching device 1 is in an upward flow holding state (i.e., it is held in an upward flow (flowing towards the first outlet flow path 22-1) state).

[0067] In addition, Figure 4In the following figures, arrows indicate the forces acting on the pump. Pressure P0 is the pressure in the upstream flow path 71, pressure P1 is the pressure in the first outlet flow path 22-1, and pressure P2 is the pressure in the second outlet flow path 22-2. Furthermore, pressure P3 is the pressure in the downstream flow path 72 (inlet flow path 21), and pressure Pa is the pressure in the back pressure chamber 31.

[0068] Next, as Figure 5 As shown, when the pilot valve 51 is switched to the open state, the pressure transmission passage 60 is connected to the first branch passage 61, while the pressure transmission passage 60 is disconnected from the second branch passage 62.

[0069] Therefore, the back pressure chamber 31 is connected to the upstream flow path 71 of the pump via the first connecting passage 41. Moreover, the pressure Pa of the back pressure chamber 31 is higher than the pressure P0 of the upstream flow path 71 of the pump. Therefore, the cooling water of the back pressure chamber 31 is discharged to the upstream flow path 71 of the pump via the first connecting passage 41, thus reducing the pressure Pa of the back pressure chamber 31 and exerting an upward force on the diaphragm 24.

[0070] Then, the diaphragm 24 moves upward, and the drive shaft 25 is driven upward, thereby separating the valve core 26 from the second valve seat 27-2. In this way, the flow path switching device 1 is switched to a downward flow state (a state of switching from upward flow to downward flow).

[0071] Next, as Figure 6 As shown, if the pilot valve 51 remains open, the valve core 26 abuts against the first valve seat 27-1. This opens the valve orifice of the second valve seat 27-2 (i.e., the orifice located inside the second valve seat 27-2), thus forming a flow path between the inlet flow path 21 and the outlet flow path 22-2, allowing cooling water to flow from the inlet flow path 21 to the outlet flow path 22-2. Consequently, the pressure of the cooling water flowing from the inlet flow path 21 to the outlet flow path 22-2 acts upwards (i.e., towards the first valve seat 27-1) on the valve core 26. Thus, the flow path switching device 1 remains in a downward flow holding state (maintaining a downward flow (towards the second outlet flow path 22-2)).

[0072] Next, as Figure 7 As shown, when the pilot valve 51 is switched to the closed state, the pressure transmission passage 60 is disconnected from the first branch passage 61, while the pressure transmission passage 60 is connected to the second branch passage 62.

[0073] Therefore, the back pressure chamber 31 is connected to the downstream flow path 72 of the pump via the second connecting passage 42. Moreover, the pressure Pa of the back pressure chamber 31 is lower than the pressure P3 of the downstream flow path 72 of the pump. Therefore, the cooling water in the downstream flow path 72 of the pump flows into the back pressure chamber 31 via the second connecting passage 42, thus the pressure Pa of the back pressure chamber 31 rises, exerting a downward force on the diaphragm 24.

[0074] Then, the diaphragm 24 moves downward, and the drive shaft 25 is driven downward, thereby separating the valve core 26 from the first valve seat 27-1. In this way, the flow path switching device 1 is switched to an upward flow state (a state of switching from downward flow to upward flow).

[0075] Then, if pilot valve 51 remains closed, then repeat the process as follows: Figure 4 As shown, the flow path switching device 1 is in an upward flow holding state.

[0076] (Effects of this implementation method)

[0077] According to this embodiment, the flow path switching device 1 has a first connecting passage 41 that connects the back pressure chamber 31 to the upstream flow path 71 of the pump and a second connecting passage 42 that connects the back pressure chamber 31 to the downstream flow path 72 of the pump. Furthermore, the flow path switching device 1 has a pilot valve 51 that switches the connection state of the first connecting passage 41 and the second connecting passage 42.

[0078] Therefore, by switching the connection state of the first connecting passage 41 and the second connecting passage 42 using the pilot valve 51, the diaphragm 24 can be freely operated using the pressures before and after the pump 12. Furthermore, the connection state of the first connecting passage 41 and the second connecting passage 42 refers to the connection state between the back pressure chamber 31 and the upstream flow path 71 and the downstream flow path 72 of the pump, achieved by the first connecting passage 41 and the second connecting passage 42. Additionally, the pressures before and after the pump 12 are the pressures upstream and downstream of the pump 12, respectively.

[0079] Therefore, the diaphragm 24 is activated by the pressure of the pump 12, which in turn drives the drive shaft 25. This allows the valve core 26 to open and close the first outlet flow path 22-1 and the second outlet flow path 22-2, thus switching the flow path.

[0080] At this time, even without cooling water flow in the first connecting passage 41 and the second connecting passage 42, the pressure before and after pump 12 can be transmitted to the back pressure chamber 31. Therefore, the decrease in pump efficiency of pump 12 can be suppressed. Thus, the decrease in pump efficiency can be suppressed, and the flow path can be switched using the pressure before and after pump 12.

[0081] Furthermore, the operating force of the flow path switching valve section 11 depends on the diameter of the diaphragm chamber 23. Therefore, for example, even without increasing the number of coil turns as in a solenoid valve, the operating force of the flow path switching valve section 11 can be increased by increasing the diameter of the diaphragm chamber 23. Thus, the size and manufacturing cost of the flow path switching device 1 can be reduced.

[0082] In addition, the diaphragm 24 only moves up and down, so there is no need to worry about foreign objects getting stuck.

[0083] In addition, since the diameter of the pressure transmission passage 60 formed between the pilot valve 51 and the diaphragm chamber 23 can be reduced, the pressure change rate can be adjusted.

[0084] In addition, since the valve core 26 is moved by the diaphragm 24, the thrust will not decrease due to the increased stroke as would occur in the case where the valve core 26 is moved by the piston.

[0085] In addition, by increasing the stroke of the valve core 26, it is possible to achieve low pressure loss.

[0086] In addition, the pilot valve 51 can be switched to either a state in which the back pressure chamber 31 is connected to the upstream flow path 71 of the pump via the first connecting path 41, or a state in which the back pressure chamber 31 is connected to the downstream flow path 72 of the pump via the second connecting path 42.

[0087] In this way, the flow path can be switched using the pressure before and after pump 12 with a simple structure. Therefore, the manufacturing cost of the flow path switching device 1 can be reduced.

[0088] In addition, in the flow path switching device 1, a diaphragm 24 is used as a movable wall that drives the drive shaft 25.

[0089] In this way, by using the diaphragm 24, which is relatively inexpensive to obtain, the manufacturing cost of the flow path switching device 1 can be suppressed.

[0090] In addition, the flow path switching device 1 is a device that integrates the flow path switching valve section 11 and the pump 12.

[0091] Therefore, the pump 12 can be configured as the drive unit of the flow path switching valve unit 11, and a compact and low-cost flow path switching device 1 can be constructed.

[0092] In addition, the flow path switching device 1 is installed in the flow path of the cooling water in the electric vehicle.

[0093] Therefore, the flow of cooling water in electric vehicles can be efficiently controlled through the flow path switching device 1. This improves the energy efficiency of electric vehicles and contributes to carbon neutrality.

[0094] <Second Implementation Method>

[0095] Next, the flow path switching device 2 of the second embodiment will be described, but the differences from the flow path switching device 1 of the first embodiment will be described, and the common points with the flow path switching device 1 of the first embodiment will be omitted.

[0096] [First Embodiment]

[0097] First, the first embodiment of the flow path switching device 2 will be described.

[0098] (Structure of the flow path switching device)

[0099] In the flow path switching device 2 of this embodiment, such as Figure 8 As shown, the diaphragm chamber 23 is sealed by a lip seal 28 and disconnected from the first outflow path 22-1. Furthermore, the diaphragm chamber 23 includes a back pressure chamber 31 and an intermediate chamber 32 separated from the back pressure chamber 31 by a diaphragm 24.

[0100] In addition, the flow path switching device 2 of this embodiment has a first connecting path 81, a second connecting path 82, and a pilot valve 91.

[0101] The first connecting passage 81 is a passage that connects the back pressure chamber 31 to the upstream flow passage 71 of the pump. The second connecting passage 82 is a passage that connects the intermediate chamber 32 to the downstream flow passage 72 of the pump. Furthermore, the second connecting passage 82 is formed by a first portion 101 and a second portion 102. The first portion 101 is formed between the intermediate chamber 32 and the pilot valve 91. Furthermore, the second portion 102 is formed between the pilot valve 91 and the downstream flow passage 72 of the pump.

[0102] Furthermore, in the flow path switching device 2 of this embodiment, an intermediate passage 83 is provided as a passage for connecting the first part 101 of the first connecting passage 81 and the second connecting passage 82.

[0103] Pilot valve 91 is a valve that switches the connection state of the first connection path 81 and the second connection path 82. That is, pilot valve 91 can be switched to either a state in which the first part 101 of the second connection path 82 is disconnected from the second part 102 while the first part 101 is connected to the intermediate passage 83, or a state in which the first part 101 is connected to the second part 102 while the first part 101 is disconnected from the intermediate passage 83. Furthermore, pilot valve 91 is an example of the "connection state switching valve" of this disclosure.

[0104] (Function of the flow path switching device)

[0105] In this embodiment, the pilot valve 91 is switched to a state in which the first part 101 of the first connecting passage 81 and the second connecting passage 82 are connected via the intermediate passage 83, thereby connecting the back pressure chamber 31 and the intermediate chamber 32 with the upstream flow passage 71 of the pump (see reference). Figure 8 (etc.), and any of the following states (refer to) where the back pressure chamber 31 is connected to the upstream flow path 71 of the pump via the first connecting path 81 and the intermediate chamber 32 is connected to the downstream flow path 72 of the pump via the second connecting path 82. Figure 10 wait).

[0106] Therefore, the following explains the specific switching of flow paths. First, as... Figure 8 As shown, the back pressure chamber 31 is connected to the upstream flow path 71 of the pump via the first connecting passage 81. Therefore, when there is no cooling water flow in the first connecting passage 81, the pressure of the upstream flow path 71 of the pump is transmitted to the back pressure chamber 31.

[0107] In addition, the pilot valve 91 is closed, the first part 101 and the second part 102 of the second connecting passage 82 are disconnected, and the first part 101 is connected to the intermediate passage 83.

[0108] Thus, the intermediate chamber 32 is connected to the upstream flow path 71 of the pump via the first portion 101 of the second connecting passage 82, the intermediate passage 83, and the first connecting passage 81. Therefore, when there is no cooling water flow in the first portion 101 of the second connecting passage 82, the intermediate passage 83, and the first connecting passage 81, the pressure of the upstream flow path 71 of the pump is transmitted to the intermediate chamber 32. Additionally, the force of the spring 33 acts downward on the diaphragm 24.

[0109] Furthermore, the valve core 26 abuts against the second valve seat 27-2, and the valve orifice of the first valve seat 27-1 is open. Therefore, a flow path is formed by the inlet flow path 21 and the first outlet flow path 22-1, and cooling water flows from the inlet flow path 21 to the first outlet flow path 22-1. Moreover, the pressure of the cooling water flowing from the inlet flow path 21 to the first outlet flow path 22-1 acts downward on the valve core 26. In this way, the flow path switching device 2 is in an upward flow maintenance state.

[0110] Next, as Figure 9 As shown, when the pilot valve 91 is switched to the open state, the first part 101 of the second connecting passage 82 is disconnected from the intermediate passage 83, while the first part 101 of the second connecting passage 82 is connected to the second part 102.

[0111] Therefore, the intermediate chamber 32 is connected to the downstream flow path 72 of the pump via the second connecting passage 82. Moreover, the pressure Pb in the intermediate chamber 32 is lower than the pressure P3 in the downstream flow path 72 of the pump. Therefore, cooling water from the downstream flow path 72 flows into the intermediate chamber 32, thus increasing the pressure Pb in the intermediate chamber 32 and exerting an upward force on the diaphragm 24.

[0112] Furthermore, the back pressure chamber 31 is connected to the upstream flow path 71 of the pump via the first connecting passage 81. Moreover, the pressure Pa of the back pressure chamber 31 is higher than the pressure P0 of the upstream flow path 71 of the pump. Therefore, the cooling water in the back pressure chamber 31 is discharged into the upstream flow path 71 of the pump, thus reducing the pressure Pa of the back pressure chamber 31 and exerting an upward force on the diaphragm 24.

[0113] Then, the diaphragm 24 moves upward, and the drive shaft 25 is driven upward, thereby separating the valve core 26 from the second valve seat 27-2. In this way, the flow path switching device 2 enters a switching state of downward flow switching.

[0114] Next, as Figure 10 As shown, if the pilot valve 91 remains open, the valve core 26 abuts against the first valve seat 27-1. This opens the valve orifice of the second valve seat 27-2, thus forming a flow path from the inlet flow path 21 to the second outlet flow path 22-2, allowing cooling water to flow from the inlet flow path 21 to the second outlet flow path 22-2. Furthermore, the pressure of the cooling water flowing from the inlet flow path 21 to the second outlet flow path 22-2 acts upwards on the valve core 26. In this way, the flow path switching device 2 maintains a downward flow state.

[0115] Next, as Figure 11 As shown, when the pilot valve 91 is switched to the closed state, the first part 101 of the second connecting passage 82 is connected to the intermediate passage 83, while the first part 101 and the second part 102 of the second connecting passage 82 are disconnected.

[0116] Therefore, the intermediate chamber 32 is connected to the upstream flow path 71 of the pump via the first part 101 of the second connecting path 82, the intermediate passage 83, and the first connecting path 81. Furthermore, the pressure Pb in the intermediate chamber 32 is higher than the pressure P0 in the upstream flow path 71. Therefore, the cooling water in the intermediate chamber 32 is discharged to the downstream flow path 72 of the pump, thus reducing the pressure Pb in the intermediate chamber 32.

[0117] Furthermore, the back pressure chamber 31 is connected to the upstream flow path 71 of the pump via the first connecting passage 81. Moreover, the pressure Pa of the back pressure chamber 31 is lower than the pressure P0 of the upstream flow path 71 of the pump. Therefore, cooling water from the upstream flow path 71 of the pump flows into the back pressure chamber 31, thus increasing the pressure Pa of the back pressure chamber 31.

[0118] Then, the diaphragm 24 moves downward, and the drive shaft 25 is driven downward, thereby separating the valve core 26 from the first valve seat 27-1. In this way, the flow path switching device 2 enters a switching state of upward flow.

[0119] Then, if pilot valve 91 remains closed, then repeat the process as follows: Figure 8 As shown, the flow path switching device 2 is in an upward flow holding state.

[0120] (The effect of this embodiment)

[0121] According to this embodiment, the pilot valve 91 is switched to either a state in which the back pressure chamber 31 and the intermediate chamber 32 are connected to the upstream flow path 71 of the pump via the intermediate passage 83 to connect the first connecting passage 81 and the second connecting passage 82, or a state in which the back pressure chamber 31 is connected to the upstream flow path 71 of the pump via the first connecting passage 81 and the intermediate chamber 32 is connected to the downstream flow path 72 of the pump via the second connecting passage 82.

[0122] In this way, in addition to the back pressure chamber 31, the pressure of the intermediate chamber 32 can also be adjusted, which can improve the responsiveness of the valve core 26. Therefore, the responsiveness of flow path switching can be improved.

[0123] [Second Embodiment]

[0124] Next, a second embodiment of the flow path switching device 2 will be described, but the differences from the first embodiment will be explained, while the common points with the first embodiment will be omitted.

[0125] (Structure of the flow path switching device)

[0126] In this embodiment, as Figure 12 As shown, a throttling section 111 is provided in the second part 102 of the second connecting path 82.

[0127] (Function of the flow path switching device)

[0128] In this embodiment, the pilot valve 91 is switched to a state in which the first part 101 of the second connecting passage 82 is connected to the first connecting passage 81 via the intermediate passage 83, thereby connecting both the back pressure chamber 31 and the intermediate chamber 32 to both the upstream flow passage 71 and the downstream flow passage 72 of the pump (see reference). Figure 12 (etc.), and the state in which the back pressure chamber 31 is connected to the upstream flow path 71 of the pump via the first connecting path 81 and the intermediate chamber 32 is connected to the downstream flow path 72 of the pump via the second connecting path 82 (refer to) Figure 13 Any one of (etc.).

[0129] Therefore, the following explains the specific switching of flow paths. First, as... Figure 12 As shown, the back pressure chamber 31 is connected to the upstream flow path 71 of the pump via the first connecting passage 81. In addition, the pilot valve 91 is in the closed state, and the back pressure chamber 31 is connected to the downstream flow path 72 of the pump via the first connecting passage 81, the intermediate passage 83 and the second part 102 of the second connecting passage 82.

[0130] The intermediate chamber 32 is connected to the downstream flow path 72 of the pump via the second connecting passage 82. In addition, the pilot valve 91 is in the closed state, and the intermediate chamber 32 is connected to the upstream flow path 71 of the pump via the first part 101 of the second connecting passage 82, the intermediate passage 83 and the first connecting passage 81.

[0131] Thus, the pilot valve 91 is configured to connect the first connecting passage 81 and the second connecting passage 82 via the intermediate passage 83, thereby connecting the back pressure chamber 31 and the intermediate chamber 32 with the upstream flow passage 71 and the downstream flow passage 72 of the pump.

[0132] Furthermore, the downstream flow path 72 of the pump is connected to the upstream flow path 71 of the pump via the second portion 102 of the second connecting path 82, the intermediate passage 83, and the first connecting path 81. Moreover, the pressure P3 in the downstream flow path 72 is higher than the pressure P0 in the upstream flow path 71. Therefore, a small leakage of cooling water occurs from the downstream flow path 72 to the upstream flow path 71 of the pump via the throttling section 111.

[0133] Therefore, the valve core 26 abuts against the second valve seat 27-2, and the valve orifice of the first valve seat 27-1 opens. Thus, a flow path is formed by the inlet flow path 21 and the first outlet flow path 22-1, and cooling water flows from the inlet flow path 21 to the first outlet flow path 22-1. Furthermore, the pressure of the cooling water flowing from the inlet flow path 21 to the first outlet flow path 22-1 acts downwards on the valve core 26. In this way, the flow path switching device 2 is in an upward flow maintenance state.

[0134] Next, as Figure 13 As shown, when the pilot valve 91 is switched to the open state, the second connecting path 82 and the intermediate path 83 are disconnected.

[0135] Therefore, the intermediate chamber 32 is connected to the downstream flow path 72 of the pump via the second connecting passage 82. Furthermore, the pressure Pb in the intermediate chamber 32 is lower than the pressure P3 in the downstream flow path 72. Thus, when there is no cooling water flow in the second connecting passage 82, the pressure in the downstream flow path 72 is transmitted to the intermediate chamber 32 via the second connecting passage 82, causing the pressure Pb in the intermediate chamber 32 to rise. In this way, the flow path switching device 2 enters the initial switching state of downward flow switching.

[0136] Next, as Figure 14 As shown, if the pilot valve 91 remains open, cooling water is discharged from the back pressure chamber 31 to the upstream flow path 71 via the first connecting passage 81 because the pressure Pa in the back pressure chamber 31 is higher than the pressure P0 in the upstream flow path 71 of the pump. Additionally, cooling water flows from the downstream flow path 72 to the intermediate chamber 32 via the second connecting passage 82 because the pressure Pb in the intermediate chamber 32 is lower than the pressure P3 in the downstream flow path 72 of the pump.

[0137] As a result, the pressure Pa in the back pressure chamber 31 decreases, while the pressure Pb in the intermediate chamber 32 increases. Then, when the following equation holds true, the diaphragm 24 moves upward, the drive shaft 25 begins to move upward, and the valve core 26 begins to separate from the second valve seat 27-2. Thus, the flow path switching device 2 is in the open state, switching the flow downwards.

[0138] [Number 1]

[0139] ((diameter of valve core 26) × P3 + force of spring 33) < (diameter of diaphragm 24 × Pb)

[0140] Next, as Figure 15 As shown, when the pilot valve 91 remains open, the valve core 26 separates from the second valve seat 27-2, and the flow path switching device 2 becomes a switching valve in the middle of the downward flow switching process.

[0141] Subsequently, when the following numerical conditions are met, the valve core 26 abuts against the first valve seat 27-1.

[0142] [Number 2]

[0143] ((diameter of diaphragm 24) × Pb) > (force of spring 33)

[0144] Next, as Figure 16 As shown, if the pilot valve 91 remains open and the following equation holds, the valve core 26 remains in contact with the first valve seat 27-1. Consequently, the valve orifice of the second valve seat 27-2 opens, thus forming a flow path from the inlet flow path 21 to the second outlet flow path 22-2, allowing cooling water to flow from the inlet flow path 21 to the second outlet flow path 22-2. In this way, the flow path switching device 1 maintains a downward flow state.

[0145] [Number 3]

[0146] ((diameter of valve core 26) × P3 + (diameter of diaphragm 24) × Pb) < (force of spring 33)

[0147] Next, as Figure 17 As shown, when the pilot valve 91 is switched to the closed state, the second connecting path 82 is connected to the intermediate path 83.

[0148] Therefore, the intermediate chamber 32 is connected to the upstream flow path 71 of the pump via the first portion 101 of the second connecting passage 82, the intermediate passage 83, and the first connecting passage 81. Furthermore, the pressure Pb in the intermediate chamber 32 is higher than the pressure P0 in the upstream flow path 71. Therefore, when there is no cooling water flow in the first portion 101, intermediate passage 83, and first connecting passage 81 of the second connecting passage 82, the pressure Pb in the intermediate chamber 32 is transmitted to the upstream flow path 71 of the pump via the first portion 101, intermediate passage 83, and first connecting passage 81, and the pressure Pb in the intermediate chamber 32 decreases. Thus, the flow path switching device 2 enters the initial switching state of upward flow switching. In addition, the intermediate chamber 32 is connected to the downstream flow path 72 of the pump via the second connecting passage 82.

[0149] Additionally, the back pressure chamber 31 is connected to the downstream flow path 72 of the pump via the second portion 102 of the first connecting passage 81, the intermediate passage 83, and the second connecting passage 82. Furthermore, the back pressure chamber 31 is connected to the upstream flow path 71 of the pump via the first connecting passage 81.

[0150] Thus, the pilot valve 91 is configured to connect the first connecting passage 81 and the second connecting passage 82 via the intermediate passage 83, thereby connecting the back pressure chamber 31 and the intermediate chamber 32 with the upstream flow passage 71 and the downstream flow passage 72 of the pump.

[0151] Next, as Figure 18 As shown, if the pilot valve 91 remains closed, cooling water flows from the upstream flow path 71 to the back pressure chamber 31 via the first connecting passage 81 because the pressure Pa in the back pressure chamber 31 is lower than the pressure P0 in the upstream flow path 71. Additionally, cooling water is discharged from the intermediate chamber 32 to the upstream flow path 71 via the first portion 101 of the second connecting passage 82, the intermediate passage 83, and the first connecting passage 81.

[0152] As a result, the pressure Pa in the back pressure chamber 31 increases, while the pressure Pb in the intermediate chamber 32 decreases. Then, when the following equation holds, the diaphragm 24 moves downwards, the drive shaft 25 begins to move downwards, and the valve core 26 begins to separate from the first valve seat 27-1. Thus, the flow path switching device 2 is in the open state, switching the flow path to upwards.

[0153] [Number 4]

[0154] ((diameter of valve core 26) × P3) < (force of spring 33)

[0155] Next, as Figure 19As shown, when the pilot valve 91 remains closed, the valve core 26 separates from the first valve seat 27-1, and the flow path switching device 2 becomes a switching valve in the middle of the upward flow switching state.

[0156] Then, by the force of spring 33, valve core 26 abuts against second valve seat 27-2. Therefore, if pilot valve 91 remains closed, flow path switching device 2 enters an upward flow holding state (see reference). Figure 12 ).

[0157] (The effect of this embodiment)

[0158] According to this embodiment, the pilot valve 91 is switched to either a state in which the first connecting passage 81 and the second connecting passage 82 are connected via the intermediate passage 83, thereby connecting both the back pressure chamber 31 and the intermediate chamber 32 to the upstream flow passage 71 and the downstream flow passage 72 of the pump, or a state in which the back pressure chamber 31 is connected to the upstream flow passage 71 of the pump via the first connecting passage 81 and the intermediate chamber 32 is connected to the downstream flow passage 72 of the pump via the second connecting passage 82.

[0159] Therefore, in addition to the back pressure chamber 31, the pressure of the intermediate chamber 32 can also be adjusted, which can improve the responsiveness of the valve core 26. Thus, the responsiveness of flow path switching can be improved.

[0160] Furthermore, the above-described embodiments are merely illustrative and do not limit this disclosure in any way. Of course, various modifications and variations can be made without departing from its spirit.

[0161] For example, as a flow path switching system of this disclosure, the flow path switching device 1 is illustrated in the above description as a device in which the flow path switching valve 11 and the pump 12 are integrally formed. However, other systems in which the flow path switching valve 11 and the pump 12 are formed separately can also be illustrated.

[0162] Explanation of reference numerals in the attached figures

[0163] 1. Flow path switching device; 2. Flow path switching device; 11. Flow path switching valve section; 12. Pump; 21. Inlet flow path; 22-1. First outlet flow path; 22-2. Second outlet flow path; 23. Diaphragm chamber; 24. Diaphragm; 25. Drive shaft; 26. Valve core; 31. Back pressure chamber; 32. Intermediate chamber; 41. First connecting path; 42. Second connecting path; 51. Pilot valve; 71. Upstream flow path of pump; 72. Downstream flow path of pump; 81. First connecting path; 82. Second connecting path; 83. Intermediate passage; 91. Pilot valve.

Claims

1. A flow path switching system, comprising: Flow path switching valve section; and The pump supplies fluid to the flow path switching valve section. The flow path switching valve includes an inlet flow path for introducing the fluid delivered by the pump, a first outlet flow path and a second outlet flow path branching from the inlet flow path and leading out the fluid, a movable chamber, a movable wall disposed within the movable chamber, a drive shaft connected to the movable wall, and a valve core disposed on the drive shaft. By actuating the movable wall, the drive shaft is driven, thereby switching the flow path by opening and closing the first outlet flow path and the second outlet flow path using the valve core. Its features are, This flow path switching system has the following features: A first connecting passage connects the movable chamber to the upstream flow path of the pump; A second connecting passage connects the movable chamber to the downstream flow path of the pump; and A connection state switching valve that switches the connection state of the first connection path and the second connection path.

2. The flow path switching system according to claim 1, characterized in that, The movable wall chamber includes a back pressure chamber separated by the movable wall. The connection state switching valve switches to either a state in which the back pressure chamber is connected to the upstream flow path of the pump via the first connection path, or a state in which the back pressure chamber is connected to the downstream flow path of the pump via the second connection path.

3. The flow path switching system according to claim 1, characterized in that, The movable wall chamber includes a back pressure chamber and an intermediate chamber separated from the back pressure chamber by the movable wall. The first connecting path is a passage that connects the back pressure chamber to the upstream flow path of the pump. The second connecting path is a passage that connects the intermediate chamber to the downstream flow path of the pump. An intermediate path is provided as a pathway to connect the first connecting path and the second connecting path. The connection state switching valve is switched to either a state in which the back pressure chamber and the intermediate chamber are connected to the upstream flow path of the pump via the intermediate passage connecting the first connection path and the second connection path, or a state in which the back pressure chamber is connected to the upstream flow path of the pump via the first connection path and the intermediate chamber is connected to the downstream flow path of the pump via the second connection path.

4. The flow path switching system according to claim 1, characterized in that, The movable wall chamber includes a back pressure chamber and an intermediate chamber separated from the back pressure chamber by the movable wall. The first connecting path is a passage that connects the back pressure chamber to the upstream flow path of the pump. The second connecting path is a passage that connects the intermediate chamber to the downstream flow path of the pump. An intermediate path is provided as a pathway to connect the first connecting path and the second connecting path. The connection state switching valve is switched to either a state in which the first connection path and the second connection path are connected via the intermediate passage, thereby connecting both the back pressure chamber and the intermediate chamber to the upstream flow path and the downstream flow path of the pump, or a state in which the back pressure chamber is connected to the upstream flow path of the pump via the first connection path and the intermediate chamber is connected to the downstream flow path of the pump via the second connection path.

5. The flow path switching system according to any one of claims 1 to 4, characterized in that, The movable wall is a diaphragm.

6. The flow path switching system according to any one of claims 1 to 4, characterized in that, The flow path switching system is a flow path switching device that is integrally formed with the flow path switching valve and the pump.

7. The flow path switching system according to any one of claims 1 to 4, characterized in that, The flow path switching system is installed in the cooling water flow path of the electric vehicle.

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