pump

Abstract

To prevent valve leakage while maintaining a valve-closed state in a pump that switches a discharge port by means of a flow of fluid.SOLUTION: A pump comprises: a pump chamber 14 having a suction port 15, a first discharge port 16, and a second discharge port 17; an impeller 18 for generating a rotational flow; and a selector valve 21 having a first valve lid 23 and a second valve lid 24 and discharging fluid from either of the first discharge port and the second discharge port depending on a direction of the rotational flow. When the rotational flow is in a first direction, the selector valve assumes a first changeover state in which the first valve lid closes the first discharge port and the second valve lid opens the second discharge port, and when the rotational flow is in a second direction, the selector valve assumes a second changeover state in which the second valve lid closes the second discharge port and the first valve lid opens the first discharge port. The selector valve includes: first contact means 25 which makes contact with the impeller to receive a force for returning the selector valve to the first changeover state from the impeller when the selector valve in the first changeover state oscillates toward the second changeover state; and second contact means 26 which makes contact with the impeller to receive a force for returning the selector valve to the second changeover state from the impeller when the selector valve in the second changeover state oscillates toward the first changeover state.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a pump, and more particularly to a pump having an integral switching valve that switches a discharge port according to a fluid flow. [Background technology]

[0002] In recent years, heat exchange systems in automobiles have become more complex. This is because automobiles are becoming more electrified from the perspective of carbon neutrality, and the number of objects to be cooled has increased, including not only the interior of the vehicle but also the motor and battery.

[0003] In such heat exchange systems, a switching valve and a water pump are provided to switch the path for circulating the cooling water in various ways depending on the operating conditions, for efficient cooling (see, for example, Patent Documents 1 and 2 below).

[0004] Furthermore, the following Patent Document 3 discloses a pump that is integrally provided with a switching valve that switches the discharge port depending on the flow of fluid. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2004-116425 A [Patent Document 2] JP 2008-213583 A [Patent Document 3] JP 2011-98628 A Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, the switching valve and water pump are usually used as a set, but in EVs (electric vehicles) and hybrid vehicles, a heat exchange system is often constructed by incorporating multiple sets of the switching valve and water pump, and each switching valve and water pump is equipped with a control motor.

[0007] Therefore, there is room for improvement in current heat exchange systems, for example, by integrating the switching valve and water pump to simplify the system and save space, or by using the flow of fluid to switch flow paths, thereby eliminating the need for a motor to control the switching valve and thereby improving energy efficiency.

[0008] On the other hand, the above-mentioned Patent Document 1 shows a water pump with an integral switching valve, which makes it possible to omit a motor for operating the switching valve. However, it is difficult to use the pump as it is in a heat exchange system for a vehicle because of the risk of valve leakage.

[0009] Specifically, the pump 1 described in Patent Document 1 is described as discharging fluid only from one of the outlets 12 (or 13) while one of the valve lid portions 24 (or 25) completely closes one of the outlets 12 (or 13) as long as the pump is operating (see paragraphs 0023-0026 of the same document), but there is a risk that the valve lid portion in the closed state will fall (swing) due to its own weight (especially when the flow rate is low), resulting in valve leakage.

[0010] Furthermore, the pump described in Patent Document 1 is a pump used in a dishwasher, which is used as a stationary appliance in the kitchen, etc., so no forces other than gravity act on it during use. In contrast, a pump mounted on an automobile may be subjected to vibrations or inertial forces on the valve cover when the vehicle travels on slopes or uneven roads, or when the vehicle accelerates or decelerates, and these effects may cause the valve cover on the closed side to open.

[0011] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to prevent valve leakage by making it possible to more reliably maintain a valve closed state in a pump equipped with a switching valve that switches a discharge port depending on the flow of fluid. [Means for solving the problem]

[0012] [First Invention] In order to solve the above problems and achieve the object, a pump according to a first aspect of the present invention includes a pump chamber having a suction port for sucking in a fluid, a first discharge port for discharging the fluid, and a second discharge port for discharging the fluid, an impeller that is installed in the pump chamber and rotated by a rotary drive device to generate a rotational flow of the fluid in the pump chamber, and a changeover valve that oscillates (rotates) when receiving the rotational flow and discharges the fluid from either the first discharge port or the second discharge port depending on the rotation direction of the rotational flow, and the changeover valve includes a first valve cover that opens and closes the first discharge port. The pump has a second lid that opens and closes a second outlet port, and a valve stem that supports the first and second lids so that they can swing, and when the rotating flow is in a first rotation direction, the pump swings under the pressure of fluid from the rotating flow to enter a first switching state in which the first lid closes the first outlet port and the second lid opens the second outlet port, while when the rotating flow is in a second rotation direction that is opposite to the first rotation direction, the pump swings under the pressure of fluid from the rotating flow to enter a second switching state in which the second lid closes the second outlet port and the first lid opens the first outlet port.

[0013] In this pump, the switching valve is provided with a first contact means that receives a swinging force from the impeller to return it to the first switching state by contacting the circumferential surface of the impeller when the switching valve in the first switching state swings toward the second switching state, and a second contact means that receives a force from the impeller to return it to the second switching state by contacting the circumferential surface of the impeller when the switching valve in the second switching state swings toward the first switching state.

[0014] The pump of the first invention described above switches the discharge port by the flow of fluid generated in the pump chamber by the impeller, and is provided with a contact means for using the rotation of the impeller to pull the valve cover back to the closed state (the state in which the discharge port is blocked) when the valve cover on the closed side (the side in a closed state with the discharge port closed) is accidentally opened.

[0015] Specifically, in this pump, a rotational flow of fluid (a flow of fluid that rotates in either a first rotational direction or a second rotational direction) is generated in the pump chamber by rotating an impeller installed in the pump chamber using a rotary drive device (e.g., an electric motor). Note that, for example, if the first rotational direction of the rotational flow is clockwise, the second rotational direction is counterclockwise.

[0016] When the direction of the rotating flow is the first rotation direction, the switching valve is pushed by the flow to swing (pivot), and the first valve cover comes into contact with and is pressed against the first outlet port, blocking the first outlet port. At this time, the second valve cover is separated from the second outlet port, and the second outlet port is opened. Therefore, the fluid that has flowed into the pump chamber from the suction port is discharged from the second outlet port (first switching state).

[0017] Here, when the switching valve receives some force (for example, the above-mentioned gravity or the vibration and inertial force caused by the vehicle traveling) in the first switching state and the first lid swings in the valve opening direction (direction away from the first discharge port), the first contact means also swings together with the first lid, and the first contact means comes into contact with the outer periphery of the rotating impeller. Due to this contact, the switching valve (the first lid via the first contact means) receives a force pulling the first lid back in the valve closing direction (direction approaching the first discharge port). Then, this force in the valve closing direction pulls the first lid back to the closed state in which it abuts against the first discharge port, making it possible to prevent fluid from leaking out of the first discharge port.

[0018] On the other hand, when the impeller is driven to rotate in the reverse direction and the direction of the rotating flow becomes the second rotation direction, the switching valve receives this flow and swings in the opposite direction to when the rotating flow was flowing in the first rotation direction, causing the second valve cover to come into contact with and be pressed against the second outlet port, closing the second outlet port. At this time, the first valve cover is separated from the first outlet port, and the first outlet port is opened. Therefore, the fluid that has flowed into the pump chamber from the suction port is discharged from the first outlet port (second switching state).

[0019] Here, when the switching valve receives some force in the second switching state, causing the second lid to swing in the valve opening direction (direction away from the second discharge port), the second contact means also swings together with the second lid, and the second contact means comes into contact with the outer periphery of the rotating impeller. Due to this contact, the switching valve (the second lid via the second contact means) receives a force pulling the second lid back in the valve closing direction (direction approaching the second discharge port). Then, this force in the valve closing direction pulls the second lid back to the closed state in which it abuts against the second discharge port, making it possible to prevent fluid from leaking out of the second discharge port.

[0020] [First aspect of the first invention] As a specific structure of the contact means, in a first aspect of the first invention, the first contact means is a first contact arm that extends from the second cover toward the circumferential surface of the impeller and receives a force returning to the first switching state by sliding against the circumferential surface of the impeller, and the second contact means is a second contact arm that extends from the first cover toward the circumferential surface of the impeller and receives a force returning to the second switching state by sliding against the circumferential surface of the impeller. Note that "sliding contact" means contact in a sliding state, that is, the contact arm contacts the circumferential surface of the impeller while the impeller is rotating (the same applies below).

[0021] In addition, it is preferable that the first contact arm and the second contact arm are lower in height than the first valve cover and the second valve cover so that the rotating flow is directed against the valve cover (first valve cover and second valve cover) to ensure more reliable operation of the switching valve (the same applies to the first contact rotor and second contact rotor described below).

[0022] In the first invention, in the completely closed state, i.e., in the first switching state where the first valve cover completely blocks the first discharge port, and in the second switching state where the second valve cover completely blocks the second discharge port, the contact means (the first contact means and the second contact means) do not come into contact with the impeller, and only come into contact with the impeller when they are swung by a certain angle in the valve opening direction. This is to prevent wear on the contact means and the impeller. The smaller the certain angle (the amount of swing at which the contact means starts to come into contact with the impeller) is set, the greater the effect of preventing valve leakage.

[0023] [Second aspect of the first aspect] In a second aspect of the first invention, the first contact means is a first contact rotor that is rotatably held between the second valve cover and the peripheral surface of the impeller in the first switching state, and the first contact rotor rotates on its own axis by contacting the peripheral surface of the impeller when the switching valve in the first switching state swings toward the second switching state, and receives a force from the impeller to return it to the first switching state, and the second contact means is a second contact rotor that is rotatably held between the first valve cover and the peripheral surface of the impeller in the second switching state, and the second contact rotor rotates on its own axis by contacting the peripheral surface of the impeller when the switching valve in the second switching state swings toward the first switching state, and receives a force from the impeller to return it to the second switching state.

[0024] According to the second aspect described above, since the contact means in contact with the impeller rotates (spins on its axis), it is possible to further reduce wear on the contact means and the impeller compared to when the contact means is in sliding contact with the impeller.

[0025] The contact rotors (first contact rotor and second contact rotor) may be, for example, cylindrical members or spheres. When the contact rotors are made of cylindrical members, the axis of the cylindrical member may be provided in the switching valve so as to be parallel to the valve shaft of the switching valve and the rotation axis of the impeller.

[0026] The first invention described above is configured so that the contact means does not come into contact with the impeller in the fully closed state, but this application does not exclude a structure in which the contact means comes into contact with the impeller even in the fully closed state. This is because such a structure can also prevent the valve lid from accidentally opening when the valve is closed. The second invention described below has such a structure.

[0027] [Second Invention] A pump according to a second aspect of the present invention includes a pump chamber having a suction port for sucking in a fluid, a first discharge port for discharging the fluid, and a second discharge port for discharging the fluid, an impeller that is disposed in the pump chamber and rotated by a rotary drive device to generate a rotational flow of the fluid in the pump chamber, and a changeover valve that oscillates upon receiving the rotational flow and discharges the fluid from either the first discharge port or the second discharge port depending on the rotation direction of the rotational flow, and the changeover valve has a first valve cover that opens and closes the first discharge port, and a second valve cover that opens and closes the second discharge port. and a valve stem portion supporting the first and second valve lids so that they can swing. When the rotating flow is in a first rotation direction, the pump swings under the pressure of fluid from the rotating flow, entering a first switching state in which the first valve lid closes the first outlet port and the second valve lid opens the second outlet port, while when the rotating flow is in a second rotation direction that is opposite to the first rotation direction, the pump swings under the pressure of fluid from the rotating flow, entering a second switching state in which the second valve lid closes the second outlet port and the first valve lid opens the first outlet port.

[0028] In this pump, the switching valve is provided with a first contact means that receives a force from the impeller to press the first valve cover against the first discharge port by contacting the circumferential surface of the impeller when the switching valve is in a first switching state, and a second contact means that receives a force from the impeller to press the second valve cover against the second discharge port by contacting the circumferential surface of the impeller when the switching valve is in a second switching state.

[0029] In the second aspect of the present invention, the contact means (first contact means and second contact means) and the impeller (particularly the circumferential surface with which the contact means come into contact) are preferably made of a material having excellent wear resistance.

[0030] [First aspect of the second aspect of the invention] Furthermore, in the first aspect of the pump of the second invention, as in the pump of the first invention, the first contact means is a first contact arm extending from the second lid toward the circumferential surface of the impeller and receiving a force from the impeller to press the first lid against the first outlet port by coming into sliding contact with the circumferential surface of the impeller when in the first switching state, and the second contact means is a second contact arm extending from the first lid toward the circumferential surface of the impeller and receiving a force from the impeller to press the second lid against the second outlet port by coming into sliding contact with the circumferential surface of the impeller when in the second switching state.

[0031] [Second aspect of the second invention] In a second aspect of the second invention, the first contact means is a first contact rotor that is rotatably held between the second valve cover and the peripheral surface of the impeller, and rotates by contacting the peripheral surface of the impeller in the first switching state and receives a force from the impeller to press the first valve cover against the first outlet port, and the second contact means is a second contact rotor that is rotatably held between the first valve cover and the peripheral surface of the impeller, and rotates by contacting the peripheral surface of the impeller in the second switching state and receives a force from the impeller to press the second valve cover against the second outlet port.

[0032] [Specific aspects of the first and second inventions] Furthermore, in the first and second inventions, as a more specific embodiment, when, among the inner surfaces defining the pump chamber, one inner surface in the direction of the rotational axis of the impeller is defined as the bottom surface and the inner surface in the direction perpendicular to the rotational axis is defined as the circumferential surface, the suction port is formed in the bottom surface of the pump chamber, the first discharge port and the second discharge port are formed in the circumferential surface of the pump chamber, and a switching valve is provided so that the valve shaft portion is parallel to the rotational axis of the impeller.

[0033] In this aspect, the valve stem portion may be arranged on a line connecting the center between the first discharge port and the second discharge port and the rotation axis of the impeller, and the first valve cover and the second valve cover may be configured so that their tips open in a V shape toward the impeller, with the valve stem portion as their base end.

[0034] [Third Invention] Furthermore, the pump according to the third invention of the present application does not open and close the first and second outlets (switching the outlet) with a single switching valve as in the first and second inventions, but rather has two switching valves, namely a first switching valve that opens and closes the first outlet and a second switching valve that opens and closes the second outlet, and switches the outlet with these switching valves.

[0035] Specifically, the pump is equipped with a pump chamber having a suction port for sucking in a fluid, a first discharge port for discharging the fluid, and a second discharge port for discharging the fluid, an impeller that is installed in the pump chamber and rotated by a rotary drive device to generate a rotational flow of the fluid in the pump chamber, and a changeover valve that oscillates when it receives the rotational flow and discharges the fluid from either the first discharge port or the second discharge port depending on the rotation direction of the rotational flow, the changeover valve including a first changeover valve supported to be swingable on a first shaft portion and a second changeover valve supported to be swingable on a second shaft portion, and the first changeover valve is subjected to the pressure of the fluid when the rotational flow is in a first rotation direction. the first switching valve comprises a first valve cover which oscillates the first switching valve and closes the first outlet, and a first valve opening plate which, when the rotating flow is in a second rotational direction that is opposite to the first rotational direction, oscillates the first switching valve under the pressure of the fluid, thereby opening the first outlet that was closed by the first valve cover; the second switching valve comprises a second valve cover which oscillates the second switching valve and closes the second outlet by the pressure of the fluid, when the rotating flow is in the second rotational direction, and a second valve opening plate which oscillates the second switching valve under the pressure of the fluid, when the rotating flow is in the first rotational direction, thereby opening the second outlet that was closed by the second valve cover.

[0036] Furthermore, in this pump, when a state in which the rotating flow is in a first rotation direction and the first valve cover closes the first outlet port and the second valve cover opens the second outlet port is defined as a first switching state, and a state in which the rotating flow is in a second rotation direction and the second valve cover closes the second outlet port and the first valve cover opens the first outlet port is defined as a second switching state, the first switching valve is provided with a first contact means that comes into contact with a circumferential surface of the impeller when the first switching valve in the first switching state swings in a direction to open the first outlet port, thereby receiving a force from the impeller to close the first outlet port, and the second switching valve is provided with a second contact means that comes into contact with the circumferential surface of the impeller when the second switching valve in the second switching state swings in a direction to open the second outlet port.

[0037] According to the third invention, it is possible to increase the degree of freedom in the installation position of the discharge ports. That is, in the first and second inventions, since the discharge ports are switched by one switching valve, the first and second discharge ports must be located in close positions (within the range that the first and second valve covers provided on one switching valve can reach), but according to the third invention, the first and second discharge ports are opened and closed by switching valves that are not related to each other (provided separately), so the first and second discharge ports can be located more freely than in the first and second inventions. For example, according to the third invention, it is also possible to place the second discharge port on the opposite side of the first discharge port across the impeller.

[0038] In addition, in the above third invention, the first valve plate extends toward the circumferential surface of the impeller and has a first contact means at its tip, which receives a force from the impeller to return it to the first switching state by coming into sliding contact with the circumferential surface of the impeller, and the second valve plate extends toward the circumferential surface of the impeller and has a second contact means at its tip, which receives a force from the impeller to return it to the second switching state by coming into sliding contact with the circumferential surface of the impeller.

[0039] Furthermore, in the third aspect of the invention, it is possible to make the contact means contact the impeller to maintain the valve closed even in the fully closed state, as in the second aspect of the invention. The following fourth aspect of the invention has such a structure.

[0040] [Fourth Invention] A pump according to a fourth aspect of the present invention is a pump comprising: a pump chamber having a suction port for sucking in a fluid, a first discharge port for discharging the fluid, and a second discharge port for discharging the fluid; an impeller that is disposed in the pump chamber and rotated by a rotary drive device to generate a rotational flow of the fluid in the pump chamber; and a changeover valve that oscillates when it receives the rotational flow and discharges the fluid from either the first discharge port or the second discharge port depending on the rotational direction of the rotational flow, wherein the changeover valve includes a first changeover valve that is swingably supported on a first shaft portion and a second changeover valve that is swingably supported on a second shaft portion, and the first changeover valve receives pressure of the fluid when the rotational flow is in a first rotation direction. the first switching valve comprises a first valve cover which oscillates the first switching valve and closes a first outlet port, and a first valve opening plate which, when the rotating flow is in a second rotational direction that is opposite to the first rotational direction, oscillates the first switching valve under fluid pressure, thereby opening the first outlet port that was closed by the first valve cover; the second switching valve comprises a second valve cover which oscillates the second switching valve and closes the second outlet port under fluid pressure, when the rotating flow is in the second rotational direction, and a second valve opening plate which oscillates the second switching valve under fluid pressure, when the rotating flow is in the first rotational direction, thereby opening the second outlet port that was closed by the second valve cover.

[0041] In this pump, a first switching state is a state in which the rotating flow is in a first rotation direction and the first valve cover blocks the first outlet port and the second valve cover opens the second outlet port, and a second switching state is a state in which the rotating flow is in a second rotation direction and the second valve cover blocks the second outlet port and the first valve cover opens the first outlet port.When this state is, the first switching valve is provided with a first contact means that receives a force from the impeller to press the first valve cover against the first outlet port by contacting a circumferential surface of the impeller when the first switching valve is in the first switching state, and the second switching valve is provided with a second contact means that receives a force from the impeller to press the second valve cover against the second outlet port by contacting a circumferential surface of the impeller when the second switching valve is in the second switching state.

[0042] In the pump of the fourth invention, the first valve plate extends toward the circumferential surface of the impeller and is provided with a first contact means at its tip, which comes into sliding contact with the circumferential surface of the impeller to press the first valve cover against the first outlet port, and the second valve plate extends toward the circumferential surface of the impeller and is provided with a second contact means at its tip, which comes into sliding contact with the circumferential surface of the impeller to press the second valve cover against the second outlet port.

[0043] [Specific aspects of the third and fourth inventions] In the third and fourth inventions, a valve open keeping arm may be further provided as a means for maintaining the open valve state, and the means (valve open keeping arm) may take either of the following forms (1) or (2).

[0044] (1) The first switching valve further includes a first open valve maintaining arm that receives a force from the impeller to fully open the first discharge port by coming into sliding contact with the circumferential surface of the impeller when the first switching valve in the second switching state swings in a direction to close the first discharge port, and the second switching valve further includes a second open valve maintaining arm that receives a force from the impeller to fully open the second discharge port by coming into sliding contact with the circumferential surface of the impeller when the second switching valve in the first switching state swings in a direction to close the second discharge port.

[0045] In the embodiment (1), when the switching valve (first switching valve or second switching valve) in the open state swings in the closing direction, the valve open holding arm pulls it back to the open (fully open) state. On the other hand, in the next embodiment (2), the valve open holding arm comes into contact with the impeller even in the fully open state, and receives a force from the impeller to maintain the fully open state.

[0046] (2) The first switching valve further includes a first open valve maintaining arm that receives a force from the impeller to oscillate the first valve cover in a direction to fully open the first discharge port by coming into sliding contact with the circumferential surface of the impeller when the first switching valve is in the second switching state, and the second switching valve further includes a second open valve maintaining arm that receives a force from the impeller to oscillate the second valve cover in a direction to fully open the second discharge port by coming into sliding contact with the circumferential surface of the impeller when the second switching valve is in the first switching state.

[0047] In addition, in the third and fourth inventions, when, of the inner surfaces defining the pump chamber, one inner surface in the direction of the rotational axis of the impeller is defined as the bottom surface and the inner surface in the direction perpendicular to the rotational axis is defined as the circumferential surface, an intake port may be formed in the bottom surface of the pump chamber, a first discharge port and a second discharge port may be formed in the circumferential surface of the pump chamber, a first switching valve may be provided so that the first shaft portion is parallel to the rotational axis of the impeller, and a second switching valve may be provided so that the second shaft portion is parallel to the rotational axis of the impeller. Effect of the Invention

[0048] According to the present invention, the valve can be more reliably maintained in a closed state to prevent valve leakage. In addition, according to the present invention, since it is not necessary to provide a drive device (motor, etc.) for driving the switching valve, it is possible to conserve energy and simplify the control unit of the heat exchange system by reducing the number of controlled objects.

[0049] Other objects, features, and advantages of the present invention will become apparent from the following description of the embodiments of the present invention based on the drawings. Note that the present invention is not limited to the following embodiments, and it is obvious to those skilled in the art that various modifications can be made within the scope of the claims. In addition, the same reference numerals in each drawing indicate the same or corresponding parts. [Brief description of the drawings]

[0050] [Figure 1] FIG. 1 is a perspective view showing the internal structure of a pump according to a first embodiment of the present invention (with a drive unit, a cover, and a top plate of an impeller removed). [Diagram 2] FIG. 2 is a vertical cross-sectional view showing the pump according to the first embodiment. [Diagram 3] FIG. 3 is a plan view showing the internal structure of the pump according to the first embodiment (in a state in which a drive device, a lid, and a top plate of an impeller are removed / first switching state). [Figure 4] FIG. 4 is a plan view showing the internal structure of the pump according to the first embodiment (with the drive device, the lid, and the top plate of the impeller removed / second switching state). [Diagram 5] FIG. 5 is an enlarged plan view showing a contact arm portion (first switching state) of the pump according to the first embodiment. [Figure 6] FIG. 6 is an enlarged plan view showing a contact arm portion of the pump according to the first embodiment (a state in which the first valve cover of the switching valve in the first switching state swings in the valve opening direction and the first contact arm comes into contact with the impeller). [Figure 7] FIG. 7 is a plan view showing the internal structure of a pump according to a second embodiment of the present invention (in a state in which a drive device, a cover, and a top plate of an impeller are removed / first switching state). [Figure 8] FIG. 8 is a plan view showing the internal structure of the pump according to the second embodiment (with the drive device, the lid, and the top plate of the impeller removed / second switching state). [Figure 9] FIG. 9 is an enlarged plan view showing a contact rotor portion (first switching state) of the pump according to the second embodiment. [Figure 10] FIG. 10 is an enlarged plan view showing a contact rotor portion of the pump according to the second embodiment (a state in which the first valve cover of the switching valve in the first switching state swings in the valve opening direction and the first contact rotor comes into contact with the impeller). [Figure 11] FIG. 11 is a plan view showing the internal structure of a pump according to a third embodiment of the present invention (in a state in which a drive device, a cover, and a top plate of an impeller are removed / first switching state). [Figure 12] FIG. 12 is a plan view showing the internal structure of the pump according to the third embodiment (in a state in which the drive device, the cover, and the top plate of the impeller have been removed / second switching state). [Figure 13] FIG. 13 is a plan view showing a modified example of the pump according to the third embodiment (in a state in which the drive device, the cover, and the top plate of the impeller have been removed / first switching state). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0051] [First embodiment] As shown in Figures 1 to 6, a pump 11 according to the first embodiment of the present invention comprises a housing 12 having a pump chamber 14 therein, an impeller 18 rotatably installed within the pump chamber 14, a drive device (motor) 31 that rotates and drives the impeller 18, an intake port 15 that draws fluid into the pump chamber 14, two outlet ports 16, 17 (discharge pipes 16a, 17a) that discharge fluid from the pump chamber 14, i.e., a first outlet port 16 (first discharge pipe 16a) and a second outlet port 17 (second discharge pipe 17a), a switching valve 21 that switches between the outlet ports 16, 17 that discharge the fluid, and a lid 13 that closes the top surface of the housing 12.

[0052] In each drawing, mutually orthogonal two-dimensional or three-dimensional coordinates representing the front-rear, left-right, and up-down directions are appropriately shown, and the following description will be based on these directions. However, the pump according to the present invention and each embodiment can be used in various positions other than those shown in the drawings, and the front-rear, left-right, up-down directions do not impose any limitations on the configuration of each part of the present invention.

[0053] Impeller 18 is installed in the center of pump chamber 14 so that central axis A, which serves as the center of rotation, is parallel to the vertical direction, and suction port 15 is formed below it (at the center of the bottom surface of pump chamber 14). Meanwhile, a drive unit 31 that drives impeller 18 is installed above impeller 18. Drive unit 31 has a rotor 32 with impeller 18 connected to its lower end, a shaft 35 that rotatably supports rotor 32, and a stator 33 that includes coil 34 and generates a magnetic field that rotates rotor 32.

[0054] The rotor 32 is housed in a cylindrical portion 13a formed to protrude upward from the center of the cover 13 that closes the top surface (upper surface) of the pump chamber 14 in a watertight manner, and a stator 33 is provided on the outside of the cylindrical portion 13a. The shaft 35 extends upward from the center of the impeller 18 along the central axis (rotation axis) A of the impeller 18 that extends in the vertical direction, and has an upper end fixed to the upper surface of the cylindrical portion 13a of the cover 13, while its lower end is fixed to a bearing member 19 arranged in the center of the suction port 15. The bearing member 19 is supported on the inner circumferential surface of the suction port 15 by a plurality of legs 19a.

[0055] The impeller 18, which is driven to rotate by the drive unit 31, has a plurality of vanes 18a extending radially from the central axis A between a bottom plate portion 18b and a top plate portion 18c. A hole is formed in the center of the bottom plate portion 18b to communicate the inside of the impeller 18 (the space between the bottom plate portion 18b and the top plate portion 18c) with the suction port 15. Fluid flows into the inside of the impeller 18 from the suction port 15 through this hole, and the fluid is discharged into the pump chamber 14 from between the vanes 18a by the centrifugal force of the rotating impeller 18, generating a rotating flow of fluid around the impeller 18 (along the inner circumferential surface 14a of the pump chamber 14). The rotation direction of the rotating flow coincides with the rotation direction of the impeller 18. In addition, a hole for connecting the rotor 32 is provided in the center of the top plate portion 18c, and the rotor 32 and the impeller 18 are connected by fitting the lower end of the rotor 32 into this hole.

[0056] The first discharge port 16 and the second discharge port 17 are formed on the front peripheral surface of the pump chamber 14 so as to be aligned on the left and right, and discharge pipes (first discharge pipe 16a and second discharge pipe 17a) are provided integrally with the housing 12 so as to discharge fluid from each of the discharge ports 16, 17. A changeover valve 21 is disposed at a middle position between the first discharge port 16 and the second discharge port 17. The changeover valve 21 has a valve stem 22 whose lower end is swingably (rotatably) supported by the housing 12 and whose upper end is swingably (rotatably) supported by the lid body 13 so as to extend in the vertical direction, and two flat valve lids (first valve lid 23 and second valve lid 24) provided so as to extend horizontally (in a direction perpendicular to the vertical direction) from the outer peripheral surface of the middle part of the valve stem 22.

[0057] These two valve lids 23, 24 have a planar V-shape that opens out (is open) toward the impeller 18 so as to form a certain angle (obtuse angle) with respect to each other, and are configured to swing back and forth around the valve stem portion 22 so that when the first valve lid 23 closes the first outlet port 16, the second valve lid 24 opens the second outlet port 17, and when the second valve lid 24 closes the second outlet port 17, the first valve lid 23 opens the first outlet port 16.

[0058] Furthermore, the rear side of each valve cover 23, 24 is provided with contact arms 25, 26 for pulling the outlet port back to the closed state when the outlet port to be closed starts to be unintentionally opened.

[0059] Specifically, the first contact arm 25, which prevents valve leakage from the first discharge port 16, extends from the back surface (rear surface) of the tip of the second valve cover 24 toward the impeller 18 (rearward) while curving (drawing an arc) in a convex shape toward the impeller 18, and has a curved outer peripheral surface.

[0060] In addition, the first contact arm 25 is not in contact with the impeller 18 and is separated from the impeller 18 in the first switching state (see FIG. 3) in which the first valve cover 23 closes the first discharge port 16, as shown in FIG. 5, but when the switching valve 21 swings so that the first valve cover 23 moves away from the first discharge port 16 in this first switching state (see arrow C1 in FIG. 5), the first contact arm 25 comes into contact with the outer circumferential surface of the impeller 18 as shown in FIG. 6 (the contact portion is shown by the symbol P). Then, due to this contact, the first contact arm 25 receives a force C2 from the impeller 18 rotating in the direction shown by the arrow R1 in FIG. 6, and the first contact arm 25 swings in the direction of the arrow C3 due to this force C2, and is pulled back to the first switching state in which the first discharge port 16 is completely closed by the first valve cover 23. In this way, it is possible to prevent the fluid from leaking out from the first discharge port 16.

[0061] In addition, the extent to which the switching valve 21 must swing from the first switching state for the first contact arm 25 to come into contact with the impeller 18 (the amount of swing at which contact begins is referred to as the "contact swing amount", and the part of the contact arm at which contact begins is referred to as the "contact point" (indicated by the symbol P)) can be determined by the shape of the outer circumferential surface (rear surface) of the first contact arm 25, but the smaller the contact swing amount is set, the more completely valve leakage can be prevented.

[0062] For example, in the present invention, the first contact arm 25 may be made to contact the impeller 18 in the first switching state (a state in which the first valve cover 23 completely closes the first discharge port 16), in which case the contact swing amount is zero and the valve leakage amount is minimized. However, from the viewpoint of preventing wear of the contact arm 25 and the impeller 18, it is preferable to have a structure in which the contact arms 25, 26 do not contact the impeller 18 in the first switching state as in this embodiment and in a second switching state described below.

[0063] The shape of the contact arm outer circumferential surface 25a (see FIG. 6) on the tip side of the contact point P may be a curved shape that continues to be in contact with the impeller 18 when the switching valve 21 further swings in the direction of the arrow C1 (the direction in which the opening of the first discharge port 16 becomes larger), or may be a curved shape that loses contact with the impeller 18 (moves away from the outer circumferential surface of the impeller 18). However, the shape of the outer circumferential surface of the contact arm 25 is a shape that does not hinder the swinging action of the switching valve 21 from the first switching state to the second switching state when the rotation of the impeller 18 is reversed to switch the discharge ports 16, 17 (the same applies to the second contact arm 26 described next).

[0064] The second contact arm 26, which prevents valve leakage from the second discharge port 17, has a structure similar to that of the first contact arm 25. That is, the second contact arm 26 extends from the rear surface (rear surface) of the tip of the first valve cover 23 toward the impeller 18 while curving (drawing an arc) so as to be convex toward the impeller 18 (toward the rear), and has a curved outer circumferential surface. In the second switching state (see FIG. 4) in which the second valve cover 24 closes the second discharge port 17, the second contact arm 26 does not contact the impeller 18 and is separated from the impeller 18, but when the switching valve 21 swings so that the second valve cover 24 moves away from the second discharge port 17 in this second switching state, the second contact arm 26 comes into contact with the outer circumferential surface of the impeller 18. Due to this contact, the second contact arm 26 receives a force from the impeller 18 rotating in the direction indicated by the arrow R2 in FIG. 4. The switching valve 21 receiving this force is pulled back to the second switching state, thereby preventing the fluid from leaking out from the second discharge port 17.

[0065] In addition, the first contact arm 25 and the second contact arm 26 are both made shorter in height than the valve covers 23, 24 so that the rotating flow hits the rear surfaces of the valve covers 23, 24 to ensure more reliable operation of the switching valve 21 (see Figures 1 and 2).

[0066] The operation of the pump 11 according to this embodiment will be described.

[0067] As shown in Fig. 3, when the motor 31 is driven to rotate the impeller 18 in the clockwise direction R1, fluid is sucked into the pump chamber 14 through the suction port 15 on the lower surface of the pump chamber 14, and a rotational flow (flow of rotating fluid) in the same clockwise direction as the rotational direction of the impeller 18 is generated in the pump chamber 14. The first valve cover 23 of the switching valve 21 receives this rotational flow at its back surface (rear surface), and the switching valve 21 swings counterclockwise due to the force of the rotational flow, and the first valve cover 23 is pressed against the front inner peripheral surface of the pump chamber 14 to close the first discharge port 16. At this time, the second valve cover 24 moves away from the second discharge port 17, opening the second discharge port 17, and the fluid that has flowed into the pump chamber 14 from the suction port 15 is discharged from the second discharge port 17 through the second discharge pipe 17a to the outside of the pump 11 (see arrows W1 and W2 in Fig. 2).

[0068] In this first switching state, when the switching valve 21 swings clockwise, the first valve cover 23 moves away from the first discharge port 16, but the first contact arm 25 comes into contact with the rotating impeller 18, pushing the switching valve 21 back counterclockwise, and the first valve cover 23 is again pressed against the front inner surface of the pump chamber 14, closing the first discharge port 16 and preventing valve leakage from the first discharge port 16.

[0069] On the other hand, when the motor 31 is rotated in the reverse direction to rotate the impeller 18 in the counterclockwise direction R2 as shown in Fig. 4, the fluid is sucked into the pump chamber 14 through the suction port 15 on the lower surface of the pump chamber 14, and a rotational flow (flow of rotating fluid) in the same counterclockwise direction as the rotational direction of the impeller 18 is generated in the pump chamber 14. The second valve cover 24 of the switching valve 21 receives this rotational flow on its back surface (rear surface), and the switching valve 21 swings clockwise due to the force of the rotational flow, and the second valve cover 24 is pressed against the front inner peripheral surface of the pump chamber 14 to close the second discharge port 17. At this time, the first valve cover 23 moves away from the first discharge port 16, opening the first discharge port 16, and the fluid that has flowed into the pump chamber 14 from the suction port 15 is discharged from the first discharge port 16 to the outside through the first discharge pipe 16a.

[0070] In addition, in this second switching state, when the switching valve 21 swings counterclockwise, the second valve cover 24 moves away from the second discharge port 17, but the second contact arm 26 comes into contact with the rotating impeller 18, pushing the switching valve 21 back clockwise, and the second valve cover 24 is again pressed against the front inner surface of the pump chamber 14, closing the second discharge port 17 and preventing valve leakage from the second discharge port 17.

[0071] Second Embodiment 7 to 10, a pump 41 according to a second embodiment of the present invention, like the pump 11 according to the first embodiment, includes a housing 12 having a pump chamber 14 therein, an impeller 18 installed in the pump chamber 14, a drive device for rotating the impeller 18, an intake port 15 for drawing fluid into the pump chamber 14, two outlet ports (a first outlet port 16 and a second outlet port 17) for discharging the fluid from the pump chamber 14, a switching valve 21 for switching the outlet ports 16 and 17, and a cover for closing the top surface of the housing 12, and includes contact means for maintaining the switching state of the switching valve 21 by contacting the rotating impeller 18, but the structure of the contact means is different. Hereinafter, the same reference numerals are used for configurations similar to those of the first embodiment, and duplicated explanations are omitted, and differences are mainly described (the same applies to the third embodiment described later).

[0072] In this embodiment, instead of the contact arms, the contact means includes two rotors 43, 44 rotatably (rotatably) held between the first lid 23 and the second lid 24. These rotors 43, 44 are cylindrical members, and are rotatably (rotatably) held on a fan-shaped flange portion 42 formed between the first lid 23 and the second lid 24. For the same reason as in the first embodiment (to apply a rotating flow to the rear surfaces of the lids 23, 24 to operate the changeover valve 21 more reliably), the two rotors 43, 44 and the flange portion 42 that holds them are both made lower in height than the first lid 23 and the second lid 24.

[0073] Of the two rotors, the first rotor (corresponding to the first contact rotor of the present invention) 43 is disposed near the back surface (rear surface) of the second lid 24 and has a center axis 43a located to the right (closer to the first lid 23) of a line B connecting the rotation center axis of the impeller 18 and the valve shaft portion 22 (rotation center axis of the switching valve 21) in the first switching state in which the first lid 23 closes the first discharge port 16 as shown in FIG. 9 (see symbol d). 10, when the switching valve 21 swings in a direction in which the first valve cover 23 moves away from the first discharge port 16 (see arrow C1 in FIG. 9), the first valve cover 23 comes into contact with the outer circumferential surface of the rotating impeller 18 (see arrow R1), and receives a force from the impeller 18 that pulls the switching valve 21 back to the first switching state (see arrow C2 in FIG. 10), pushing the first valve cover 23 back to a position that closes the first discharge port 16. The point of contact of the first rotor 43 with the impeller 18 is indicated by symbol P.

[0074] On the other hand, of the two rotors, the second rotor (corresponding to the second contact rotor of the present invention) 44 is disposed near the back surface (rear surface) of the first lid 23 and such that in the second switching state in which the second lid 24 closes the second outlet port 17, its central axis is located to the left (closer to the second lid 24) of the line connecting the rotational axis of the impeller 18 and the valve shaft portion 22 (the rotational axis of the switching valve 21). Like the first rotor 43, in the second switching state in which the second lid 24 completely closes the second outlet port 17, the second rotor 44 does not come into contact with the impeller 18. However, when the switching valve 21 swings in the direction in which the second lid 24 moves away from the second outlet port 17, the second rotor 44 comes into contact with the outer peripheral surface of the rotating impeller 18 (rotating in the opposite direction to the first switching state) and receives a force from the impeller 18 to pull the switching valve 21 back to the second switching state, and pushes the second lid 24 back to a position where it closes the second outlet port 17.

[0075] The advantage of this embodiment is that when the first rotor 43 and the second rotor 44 come into contact with the impeller 18, they rotate (spin) within the retaining hole 42a of the flange portion 42. Therefore, according to this embodiment, the rotation of the contact means (rotors 43, 44) can prevent wear on the impeller 18, compared to the structure in which the contact means (contact arm) comes into sliding contact with the rotating impeller 18 as in the first embodiment.

[0076] Third Embodiment As shown in Figures 11 and 12, a pump 51 according to the third embodiment of the present invention is configured with two switching valves, namely, a first switching valve 52 that opens and closes the first outlet port 16 and a second switching valve 53 that opens and closes the second outlet port 17.

[0077] Specifically, in the pump 51 of this embodiment, a first outlet port 16 and a second outlet port 17 are arranged side by side on the front inner surface of the pump chamber 14, as in the first embodiment, and a first switching valve 52 and a second switching valve 53 are arranged between these outlet ports 16, 17.

[0078] More specifically, if the rotation direction of the rotational flow generated inside the pump chamber 14 by the impeller 18 is clockwise R1 (the state in Figure 11) is defined as the first rotation direction, and if the rotation direction is counterclockwise R2 (the state in Figure 12) is defined as the second rotation direction, with the front of the rotational flow being defined as the downstream side and the rear of the rotational flow being defined as the upstream side, the first switching valve 52 is positioned upstream of the first discharge port 16 when the rotational flow is in the first rotation direction (downstream when the rotational flow is in the second rotation direction), and the second switching valve 53 is positioned downstream of the second discharge port 17 when the rotational flow is in the first rotation direction (upstream when the rotational flow is in the second rotation direction).

[0079] The first switching valve 52 also has a first shaft portion 61 that extends in the vertical direction parallel to the rotation axis of the impeller 18 and supports the first switching valve 52 so that it can swing, a flat first valve cover 62 that extends horizontally from the outer circumferential surface of the first shaft portion 61 so as to open and close the first discharge port 16, and a flat first valve opening plate 63 that extends horizontally from the outer circumferential surface of the first shaft portion 61 towards the impeller 18.

[0080] In addition, the first valve cover 62 and the first valve plate 63 are arranged to have a V-shaped planar shape that opens from the first shaft portion 61 toward the impeller 18 (widening toward the rear), and are arranged so that when the rotating flow is in a first rotational direction, the first valve cover 62 is on the downstream side and the first valve plate 63 is on the upstream side (when the rotating flow is in a second rotational direction, the first valve cover 62 is on the upstream side and the first valve plate 63 is on the downstream side).

[0081] The first valve opening plate 63 receives the pressure (flow) of the fluid when the rotational flow becomes the second rotation direction (see FIG. 12) and swings the first switching valve 52 (first valve cover 62) in the valve opening direction (the direction in which the first valve cover 62 moves away from the first discharge port 16). The first valve opening plate 63, which swings in the valve opening direction by being pushed by the fluid rotating in the second rotation direction, stops by abutting against the inner circumferential surface of the pump chamber 14, and as a result, the first switching valve 52 becomes fully open (the state in which the first valve cover 62 is furthest from the first discharge port 16).

[0082] Further, the tip of the first valve opening plate 63 is provided with a first valve closed maintaining portion 64 (corresponding to the first contact means of the present invention) that maintains the first switching valve 52 in a closed state in the first switching state (a state in which the first switching valve 52 closes the first discharge port 16 and the second switching valve 53 opens the second discharge port 17). In the case of this embodiment, this first valve closed maintaining portion 64 comes into sliding contact with the outer circumferential surface of the impeller 18 when the first switching valve 52 in the closed state in the first rotation direction of the rotating flow swings toward the valve opening direction (the direction in which the first valve cover 62 moves away from the first discharge port 16), and receives a force from the impeller 18 via the first valve opening plate 63 and the first shaft portion 61 to push the first valve cover 62 back to a state in contact with the first discharge port 16.

[0083] Furthermore, by making the first closed valve maintaining portion 64 come into sliding contact with the outer peripheral surface of the impeller 18 even when the first switching valve 52 is in the fully closed state (the first valve cover 62 is in contact with the first discharge port 16), it is possible to configure the first closed valve maintaining portion 64 to receive a force from the impeller 18 pressing the first valve cover 62 against the first discharge port 16 via the first valve open plate 63 and the first shaft portion 61.

[0084] Furthermore, the first valve cover 62 is provided with a first open valve maintaining arm 65 that extends from the back surface (rear surface) of the first valve cover 62 toward the impeller 18 to maintain the open (fully open) state of the first switching valve 52. This first open valve maintaining arm 65 comes into sliding contact with the outer circumferential surface of the impeller 18 when the first switching valve 52, which is in the fully open state with the rotating flow in the second rotation direction as shown in Fig. 12, swings in the valve closing direction, and receives a force from the impeller 18 that pushes the first switching valve 52 back toward the fully open state.

[0085] In addition, it is also possible to configure the first open valve maintaining arm 65 so that it receives a force from the impeller 18 to maintain the first switching valve 52 in the fully open state (pressing the first open valve plate 63 against the inner surface 14a of the pump chamber 14) by sliding against the outer peripheral surface of the impeller 18 even when the first switching valve 52 is in the fully open state.

[0086] On the other hand, the second switching valve 53 has a second shaft portion 71 that extends in the vertical direction parallel to the rotation axis of the impeller 18 and supports the second switching valve 53 so that it can swing, a flat second valve cover 72 that extends horizontally from the outer circumferential surface of the second shaft portion 71 so as to open and close the second discharge port 17, and a flat second valve opening plate 73 that extends horizontally from the outer circumferential surface of the second shaft portion 71 toward the impeller 18.

[0087] In addition, the second valve cover 72 and the second valve plate 73 are arranged to have a V-shaped planar shape that opens from the second shaft portion 71 toward the impeller 18 (widens toward the rear) similar to the first switching valve 52, but unlike the first switching valve 52, they are arranged so that the second valve cover 72 is on the upstream side and the second valve plate 73 is on the downstream side when the rotating flow is in the first rotation direction (see Figure 11) (when the rotating flow is in the second rotation direction, the second valve cover 72 is on the downstream side and the second valve plate 73 is on the upstream side).

[0088] When the rotating flow becomes the first rotation direction, the second valve opening plate 73 receives the pressure (flow) of the fluid and swings the second switching valve 53 (second valve cover 72) in the valve opening direction (the direction in which the second valve cover 72 moves away from the second discharge port 17). The second valve opening plate 73, which swings in the valve opening direction by being pushed by the fluid rotating in the first rotation direction, stops by abutting against the inner circumferential surface 14a of the pump chamber 14, and this brings the second switching valve 53 into a fully open state (a state in which the second valve cover 72 is furthest from the second discharge port 17).

[0089] Further, the tip of the second valve opening plate 73 is provided with a second valve closed maintaining portion 74 (corresponding to the second contact means of the present invention) that maintains the second switching valve 53 in a closed state in the second switching state (a state in which the first switching valve 52 opens the first discharge port 16 and the second switching valve 53 closes the second discharge port 17). In the case of this embodiment, this second valve closed maintaining portion 74 comes into sliding contact with the outer circumferential surface of the impeller 18 when the second switching valve 53 in the closed state in the second rotational direction of the rotating flow swings toward the valve opening direction (the direction in which the second valve cover 72 moves away from the second discharge port 17), and receives a force from the impeller 18 via the second valve opening plate 72 and the second shaft portion 71 to push the second valve cover 72 back into contact with the second discharge port 17.

[0090] Furthermore, by making the second closed valve maintaining portion 74 come into sliding contact with the outer peripheral surface of the impeller 18 even when the second switching valve 53 is in a fully closed state (a state in which the second valve lid 72 abuts the second discharge port 17), it is possible to configure the second closed valve maintaining portion 74 to receive a force from the impeller 18 pressing the second valve lid 72 against the second discharge port 17 via the second valve opening plate 73 and the second shaft portion 71.

[0091] Furthermore, the second valve cover 72 is provided with a second open valve maintaining arm 75 that extends from the back surface (rear surface) of the second valve cover 72 toward the impeller 18 to maintain the open (fully open) state of the second changeover valve 53. This second open valve maintaining arm 75 comes into sliding contact with the outer circumferential surface of the impeller 18 when the second changeover valve 53, which is in the fully open state in the first rotational direction, swings in the valve closing direction as shown in Fig. 11, and receives a force from the impeller 18 that pushes the second changeover valve 53 back toward the fully open state.

[0092] In addition, it is also possible to configure the second open valve maintaining arm 75 so that it receives a force from the impeller 18 to maintain the second switching valve 53 in the fully open state (pressing the second open valve plate 73 against the inner surface 14a of the pump chamber 14) by sliding against the outer peripheral surface of the impeller 18 even when the second switching valve 53 is in the fully open state.

[0093] The operation of the pump 51 according to this embodiment will be described.

[0094] 11, when the motor is driven to rotate the impeller 18 in the clockwise direction R1, fluid is sucked into the pump chamber 14 from the suction port 15 on the lower surface of the pump chamber 14, and a rotational flow in the same clockwise direction as the rotational direction R1 of the impeller 18 is generated inside the pump chamber 14. The first valve cover 62 of the first switching valve 52 receives this rotational flow and is pushed by the rotational flow to swing counterclockwise around the first shaft portion 61, and the first valve cover 62 is pushed against the front inner circumferential surface of the pump chamber 14, closing the first discharge port 16.

[0095] Meanwhile, the second switching valve 53 receives the above-mentioned rotating flow at the second valve opening plate 73 and is pushed by the rotating flow, causing it to swing counterclockwise around the second shaft portion 71, and the second valve lid 72 enters an open state in which it opens the second discharge port 17, and the fluid that has flowed into the pump chamber 14 from the suction port 15 is discharged from the second discharge port 17 to the outside through the second discharge pipe 17a.

[0096] In this first switching state, when the first changeover valve 52 swings clockwise, the first valve cover 62 moves away from the first discharge port 16, but the first valve closed maintaining portion 64 comes into contact with the rotating impeller 18, pushing the first changeover valve 52 (first valve cover 62) back counterclockwise, and the first valve cover 62 is again pressed against the front inner circumferential surface of the pump chamber 14, closing the first discharge port 16. This makes it possible to prevent valve leakage from the first discharge port 16.

[0097] In the first switching state, when the second changeover valve 53 swings clockwise, the second valve cover 72 approaches the second discharge port 17, but the second open valve maintaining arm 75 comes into contact with the rotating impeller 18, causing the second changeover valve 53 (second valve cover 72) to swing counterclockwise and be pushed back to the fully open state. This maintains the second discharge port 17 in the fully open state.

[0098] On the other hand, when the motor is rotated in the reverse direction to rotate the impeller 18 in the counterclockwise direction R2 as shown in Fig. 12, fluid is sucked into the pump chamber 14 from the suction port 15 on the lower surface of the pump chamber 14, and a counterclockwise rotational flow, which is the same as the rotational direction of the impeller 18, is generated inside the pump chamber 14. The second valve cover 72 of the second switching valve 53 receives this rotational flow and is pushed by the rotational flow to swing clockwise, and the second valve cover 72 closes the second discharge port 17. The first switching valve 52 also swings clockwise as the first valve opening plate 63 receives the rotational flow, and the first valve cover 62 is opened away from the first discharge port 16, and the fluid that has flowed into the pump chamber 14 from the suction port 15 is discharged from the first discharge port 16 to the outside through the first discharge pipe 16a.

[0099] In addition, in this second switching state, when the second changeover valve 53 swings counterclockwise, the second valve cover 72 moves away from the second discharge port 17, but the second valve closed maintaining portion 74 comes into contact with the rotating impeller 18, pushing the second changeover valve 53 (second valve cover 72) back counterclockwise, and the second valve cover 72 is again pressed against the front inner circumferential surface of the pump chamber 14, closing the second discharge port 17. This makes it possible to prevent valve leakage from the second discharge port 17.

[0100] In the second switching state, when the first switching valve 52 swings counterclockwise, the first valve cover 62 approaches the first discharge port 16, but the first open valve maintaining arm 65 comes into contact with the rotating impeller 18, pushing the first switching valve 52 (first valve cover 62) back to the fully open state. This maintains the first discharge port 16 in the fully open state.

[0101] The advantage of this embodiment is that the switching valve for switching between the discharge ports 16, 17 is composed of two independent switching valves (first switching valve 52 and second switching valve 53), thereby increasing the freedom in the placement of the discharge ports 16, 17.

[0102] In the first and second embodiments, switching is performed by a single switching valve 21, so the two outlets 16, 17 need to be located relatively close to each other. However, according to this embodiment, it is possible to arrange the second outlet 17 on the opposite side of the first outlet 16 across the impeller 18 as shown in FIG. 13, for example, and the first outlet 16 and the second outlet 17 can be arranged at any position on the periphery of the pump chamber, making it possible to set the fluid discharge direction in various directions. [Explanation of symbols]

[0103] A central axis (rotation axis) B: A line connecting the central axis of the impeller and the valve shaft (the central axis of the swing of the switching valve) P contact point W1,W2 Fluid flow 11,41,51 Pump 12. Chassis 13 Lid 13a Cylindrical part 14 Pump Room 14a Inner surface of pump chamber 15 Intake port 16 1st outlet 16a 1st discharge pipe 17 2nd outlet 17a 2nd discharge pipe 18 Impeller 18a Feather 18b Bottom plate part 18c Top plate 19 Bearing materials 19a Legs 21 Switching valve 22 Valve stem 23,62 First operculum 24,72 Second operculum 25 First Contact Arm 26 Second contact arm 31 Drive unit (motor) 32 Rotor 33 Stator 34 Coil 35 Shaft 42 Flange part 42a retaining hole 43 First Rotating Body 43a Central axis of the first rotating body (central axis of rotation) 44 Second Rotating Body 52 First switching valve 53 Second switching valve 61 First shaft 63 First valve plate 64 First valve closing maintenance section 65 First valve opening maintenance arm 71 Second shaft 73 Second valve plate 74 Second valve closing maintenance section 75 Second valve opening maintenance arm

Claims

1. a pump chamber having a suction port for sucking in a fluid, a first discharge port for discharging the fluid, and a second discharge port for discharging the fluid; an impeller disposed in the pump chamber and rotated by a rotary drive device to generate a rotational flow of the fluid in the pump chamber; a switching valve that oscillates by receiving the rotating flow and discharges the fluid from either the first discharge port or the second discharge port depending on a rotation direction of the rotating flow; Equipped with The switching valve is a first valve cover for opening and closing the first discharge port; a second valve cover for opening and closing the second discharge port; a valve stem portion that supports the first valve cover and the second valve cover so as to be able to swing; having When the rotating flow is in a first rotation direction, the first valve cover swings under pressure of the fluid caused by the rotating flow, and enters a first switching state in which the first valve cover closes the first outlet port and the second valve cover opens the second outlet port. When the rotating flow is in a second rotation direction that is opposite to the first rotation direction, the valve lid swings under pressure of the fluid caused by the rotating flow, and enters a second switching state in which the second valve lid closes the second outlet port and the first valve lid opens the first outlet port. A pump comprising: a first contact means that, when the switching valve in the first switching state is swung toward the second switching state, comes into contact with a peripheral surface of the impeller, thereby receiving a force from the impeller to return the switching valve to the first switching state; a second contact means that, when the switching valve in the second switching state is swung toward the first switching state, comes into contact with a peripheral surface portion of the impeller, thereby receiving a force from the impeller to return the switching valve to the second switching state; The switching valve is provided with A pump characterized by:

2. The first contact means is a first contact arm extending from the second valve cover toward a peripheral surface of the impeller and receiving a force to return to the first switching state by sliding against the peripheral surface of the impeller; and The second contact means is a second contact arm extending from the first valve cover toward a peripheral surface of the impeller and receiving a force to return to the second switching state by sliding against the peripheral surface of the impeller; is 2. The pump of claim 1.

3. The first contact arm and the second contact arm are both lower in height than the first valve cover and the second valve cover.

3. The pump of claim 2.

4. the first contact means is a first contact rotor that is rotatably held between the second valve cover and a peripheral surface of the impeller in the first switching state, the first contact rotor rotates about its axis by contacting a peripheral surface portion of the impeller when the switching valve in the first switching state swings toward the second switching state, and receives a force from the impeller to return the first switching state; the second contact means is a second contact rotor that is rotatably held between the first valve cover and a peripheral surface of the impeller in the second switching state, When the switching valve in the second switching state swings toward the first switching state, the second contact rotor comes into contact with a peripheral surface portion of the impeller, thereby rotating about its axis and receiving a force from the impeller to return the valve to the second switching state.

2. The pump of claim 1.

5. The first contact rotor and the second contact rotor are both lower in height than the first valve cover and the second valve cover.

5. The pump of claim 4.

6. a pump chamber having a suction port for sucking in a fluid, a first discharge port for discharging the fluid, and a second discharge port for discharging the fluid; an impeller disposed in the pump chamber and rotated by a rotary drive device to generate a rotational flow of the fluid in the pump chamber; a switching valve that oscillates by receiving the rotating flow and discharges the fluid from either the first discharge port or the second discharge port depending on a rotation direction of the rotating flow; Equipped with The switching valve is a first valve cover for opening and closing the first discharge port; a second valve cover for opening and closing the second discharge port; a valve stem portion that supports the first valve cover and the second valve cover so as to be able to swing; having When the rotating flow is in a first rotation direction, the first valve cover swings under pressure of the fluid caused by the rotating flow, and enters a first switching state in which the first valve cover closes the first outlet port and the second valve cover opens the second outlet port. When the rotating flow is in a second rotation direction that is opposite to the first rotation direction, the valve lid swings under pressure of the fluid caused by the rotating flow, and enters a second switching state in which the second valve lid closes the second outlet port and the first valve lid opens the first outlet port. A pump comprising: a first contact means that, when the switching valve is in the first switching state, comes into contact with a peripheral surface of the impeller, thereby receiving a force from the impeller that presses the first valve cover against the first discharge port; a second contact means that, when the switching valve is in the second switching state, comes into contact with a peripheral surface portion of the impeller, thereby receiving a force from the impeller that presses the second valve cover against the second discharge port; The switching valve is provided with A pump characterized by:

7. The first contact means is a first contact arm extending from the second valve cover toward a peripheral surface portion of the impeller and receiving a force from the impeller pressing the first valve cover against the first discharge port by slidingly contacting the peripheral surface portion of the impeller when the impeller is in the first switching state; and The second contact means is a second contact arm extending from the first valve cover toward a peripheral surface portion of the impeller and receiving a force from the impeller pressing the second valve cover against the second discharge port by slidingly contacting the peripheral surface portion of the impeller when in the second switching state; is 7. The pump of claim 6.

8. The first contact means is a first contact rotor that is rotatably held between the second valve cover and a peripheral surface portion of the impeller, and that rotates by contacting the peripheral surface portion of the impeller in the first switching state and receives a force from the impeller that presses the first valve cover against the first discharge port. and The second contact means is a second contact rotor that is rotatably held between the first valve cover and a peripheral surface portion of the impeller, and that rotates by contacting the peripheral surface portion of the impeller in the second switching state and receives a force from the impeller that presses the second valve cover against the second discharge port. is 7. The pump of claim 6.

9. Among the inner surfaces defining the pump chamber, when one inner surface in the direction of the rotation axis of the impeller is defined as a bottom surface and the inner surface in the direction perpendicular to the direction of the rotation axis is defined as a peripheral surface, The suction port is formed on a bottom surface of the pump chamber, The first discharge port and the second discharge port are formed in a peripheral surface of the pump chamber, The valve shaft portion is arranged parallel to the rotation axis of the impeller. A pump according to any one of claims 1 to 8.

10. the valve shaft portion is disposed on a line connecting a substantial center between the first discharge port and the second discharge port and a rotation axis of the impeller, The first valve cover and the second valve cover are provided so that their tips open in a V-shape toward the impeller, with the valve stem portion being their base end.

10. The pump of claim 9.

11. a pump chamber having a suction port for sucking in a fluid, a first discharge port for discharging the fluid, and a second discharge port for discharging the fluid; an impeller disposed in the pump chamber and rotated by a rotary drive device to generate a rotational flow of the fluid in the pump chamber; a switching valve that oscillates by receiving the rotating flow and discharges the fluid from either the first discharge port or the second discharge port depending on a rotation direction of the rotating flow; A pump comprising: The switching valve is A first switching valve supported to be swingable by a first shaft portion; a second switching valve supported swingably on a second shaft portion; Including, The first switching valve is a first valve cover that receives pressure of the fluid when the rotational flow is in a first rotation direction, thereby swinging the first switching valve and closing the first discharge port; a first valve plate that receives pressure of the fluid and swings the first switching valve when the rotational flow is in a second rotational direction opposite to the first rotational direction, thereby opening the first discharge port that has been closed by the first valve cover; Equipped with The second switching valve is a second valve cover that receives pressure of the fluid when the rotational flow is in the second rotation direction, thereby swinging the second switching valve and closing the second discharge port; a second valve plate that receives pressure of the fluid and swings the second switching valve when the rotational flow is in the first rotation direction, thereby opening the second discharge port that has been closed by the second valve cover; Equipped with When a state in which the rotating flow is in the first rotation direction and the first valve cover closes the first outlet port and the second valve cover opens the second outlet port is defined as a first switching state, and when a state in which the rotating flow is in the second rotation direction and the second valve cover closes the second outlet port and the first valve cover opens the first outlet port is defined as a second switching state, The first switching valve is a first contact means for receiving a force from the impeller to pull the first discharge port in a direction to close the first discharge port by contacting a peripheral surface of the impeller when the first switching valve in the first switching state swings in a direction to open the first discharge port. Equipped with The second switching valve is a second contact means for receiving a force from the impeller to pull the second outlet port in a direction to close the second outlet port by contacting a peripheral surface of the impeller when the second switching valve in the second switching state swings in a direction to open the second outlet port. Equipped with A pump characterized by:

12. the first valve plate extends toward a peripheral surface of the impeller and includes the first contact means at a tip thereof, the first contact means receives a force from the impeller to return the impeller to the first switching state by slidingly contacting a peripheral surface of the impeller, the second valve plate extends toward a peripheral surface of the impeller and includes the second contact means at a tip thereof, The second contact means receives a force from the impeller to return the impeller to the second switching state by slidingly contacting the peripheral surface of the impeller.

12. The pump of claim 11.

13. a pump chamber having a suction port for sucking in a fluid, a first discharge port for discharging the fluid, and a second discharge port for discharging the fluid; an impeller disposed in the pump chamber and rotated by a rotary drive device to generate a rotational flow of the fluid in the pump chamber; a switching valve that oscillates by receiving the rotating flow and discharges the fluid from either the first discharge port or the second discharge port depending on a rotation direction of the rotating flow; A pump comprising: The switching valve is A first switching valve supported to be swingable by a first shaft portion; a second switching valve supported swingably on a second shaft portion; Including, The first switching valve is a first valve cover that receives pressure of the fluid when the rotational flow is in a first rotation direction, thereby swinging the first switching valve and closing the first discharge port; a first valve plate that receives pressure of the fluid and swings the first switching valve when the rotational flow is in a second rotational direction opposite to the first rotational direction, thereby opening the first discharge port that has been closed by the first valve cover; Equipped with The second switching valve is a second valve cover that receives pressure of the fluid when the rotational flow is in the second rotation direction, thereby swinging the second switching valve and closing the second discharge port; a second valve plate that receives pressure of the fluid and swings the second switching valve when the rotational flow is in the first rotation direction, thereby opening the second discharge port that has been closed by the second valve cover; Equipped with When a state in which the rotating flow is in the first rotation direction and the first valve cover closes the first outlet port and the second valve cover opens the second outlet port is defined as a first switching state, and when a state in which the rotating flow is in the second rotation direction and the second valve cover closes the second outlet port and the first valve cover opens the first outlet port is defined as a second switching state, The first switching valve is a first contact means for contacting a peripheral surface of the impeller when the first changeover valve is in the first changeover state, thereby receiving a force from the impeller pressing the first valve cover against the first discharge port. Equipped with The second switching valve is a second contact means for contacting a peripheral surface of the impeller when the second changeover valve is in the second changeover state, thereby receiving a force from the impeller pressing the second valve cover against the second discharge port. Equipped with A pump characterized by:

14. the first valve plate extends toward a peripheral surface of the impeller and includes the first contact means at a tip thereof, the first contact means receives a force from the impeller pressing the first valve cover against the first discharge port by slidingly contacting a peripheral surface of the impeller, the second valve plate extends toward a peripheral surface of the impeller and includes the second contact means at a tip thereof, The second contact means is in sliding contact with a peripheral surface of the impeller, and receives a force from the impeller to press the second valve cover against the second discharge port.

14. The pump of claim 13.

15. The first switching valve is a first valve open maintaining arm that receives a force from the impeller to fully open the first discharge port by coming into sliding contact with a peripheral surface of the impeller when the first switching valve in the second switching state swings in a direction to close the first discharge port. Further equipped with The second switching valve is a second valve open maintaining arm that receives a force from the impeller to fully open the second discharge port by slidingly contacting a peripheral surface of the impeller when the second switching valve in the first switching state swings in a direction to close the second discharge port. It also has 15. A pump according to any one of claims 11 to 14.

16. The first switching valve is a first valve open maintaining arm that receives a force from the impeller to swing the first valve lid in a direction to fully open the first discharge port by slidingly contacting a peripheral surface portion of the impeller when the first changeover valve is in the second changeover state; Further equipped with The second switching valve is a second valve open maintaining arm that receives a force from the impeller to swing the second valve lid in a direction to fully open the second discharge port by slidingly contacting a peripheral surface portion of the impeller when the second changeover valve is in the first changeover state; It also has 15. A pump according to any one of claims 11 to 14.

17. Among the inner surfaces defining the pump chamber, when one inner surface in the direction of the rotation axis of the impeller is defined as a bottom surface and the inner surface in the direction perpendicular to the direction of the rotation axis is defined as a peripheral surface, The suction port is formed on a bottom surface of the pump chamber, The first discharge port and the second discharge port are formed in a peripheral surface of the pump chamber, The first shaft portion is provided in parallel with a rotation axis of the impeller, and the first switching valve is provided. The second shaft portion is provided in parallel with the rotation axis of the impeller.

17. A pump according to any one of claims 11 to 16.

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