JP4182896B2 - Pump device and its discharge flow rate control device - Google Patents

Description

  The present invention relates to a pump device including two fixed-capacity pumps and a discharge flow rate control device thereof, and more particularly to a pump device capable of changing the discharge flow rate in multiple stages and a discharge flow rate control device thereof.

  Conventionally, there is a pump device provided with a pump that discharges fluid such as oil or water. For example, this type of pump device includes a pump that uses a prime mover such as an internal combustion engine as a drive source, and supplies hydraulic pressure / oil amount to a hydraulic circuit system of an automatic transmission of an automobile or lubricates the automatic transmission. It is used as a device for supplying hydraulic pressure / oil amount, or as a device for driving auxiliary equipment of automobiles.

  As an example of such a pump device, a composite pump disclosed in Patent Document 1 below is known. This composite pump includes a front-stage pump with a discharge flow rate Q1 and a rear-stage pump with a discharge flow rate Q2 driven by a common drive source. Further, this composite pump is provided with a four-way valve that switches between a state in which the discharge flow rate Q2 of the rear-stage side pump is added to the discharge flow rate Q1 of the front-stage side pump and a state in which it is subtracted. Specifically, this four-way valve is a valve that switches the suction and discharge directions of the rear-stage pump.

  The composite pump having such a configuration discharges the oil having the discharge flow rate “Q1 + Q2” by switching the four-way valve, while assisting the driving of the front-stage pump by driving the rear-stage pump as a hydraulic motor. The oil of “Q1-Q2” is discharged. As described above, the composite pump disclosed in Patent Document 1 discharges oil at two discharge flow rates.

  Patent Document 2 below includes a large-capacity pump with a discharge flow rate Q1 and a small-capacity pump with a discharge flow rate Q2. By switching the switching valve, oil is discharged at three stages of discharge flow rates Q1, Q2, and Q1 + Q2. Techniques to do this are disclosed.

JP-A-6-264874 JP-A-2-123284

  Here, in an apparatus provided with a member or mechanism that operates by hydraulic pressure, the operation of the hydraulic operation member or hydraulic operation mechanism is controlled in accordance with the amount of oil flowing in. For example, an automatic transmission of an automobile is provided with various hydraulic operation members and the like, and precise control for each operation is also required. Therefore, in order to cope with such a situation, a pump device capable of discharging oil at a multi-stage discharge flow rate is required.

  However, since the composite pump of Patent Document 1 has a two-stage discharge flow rate and the Patent Document 2 has a three-stage discharge flow rate, there are cases where more types of hydraulic operation members and the like are provided. When a precise discharge flow rate control is required, it cannot be handled by a conventional pump device.

  Therefore, the present invention has an object of providing a pump device and its discharge flow rate control device capable of improving the disadvantages of the conventional example and discharging oil at a larger number of stages of discharge flow rate. .

In order to achieve the above object, according to the first aspect of the present invention, a large-capacity pump that discharges a fluid with a discharge flow rate Q1 and a small-capacity pump that is driven by a common drive source with the large-capacity pump and discharges a fluid with a discharge flow rate Q2. A pump device having a capacity pump and a fluid discharge port communicating with a fluid supply destination is provided with a switching mechanism that switches the discharge flow rate from the fluid discharge port to four stages of Q1, Q2, Q1 + Q2, and Q1-Q2. . In the first aspect of the present invention, the switching mechanism is capable of sending the fluid discharged from the large capacity pump discharge port to the fluid discharge port side and from the fluid discharge port side to the large capacity pump discharge port side. The first check valve that cannot flow back to the fluid, and the fluid discharged from the small capacity pump discharge port can be sent to the fluid discharge port side, and the reverse flow from the fluid discharge port side to the small capacity pump discharge port side Of the first check valve, the third check valve capable of inflow of fluid to the small capacity pump suction port side and the reverse flow from the small capacity pump suction port side, and the first check valve A first drain oil passage that allows communication between the large-capacity pump discharge port side and the large-capacity pump suction port side, and a small-capacity pump discharge port side of the second check valve and an upstream side of the third check valve communicate with each other. 2 drain oil passage, 1st check valve large capacity pump discharge side and 3rd check valve small capacity pump A bypass oil passage for communicating the suction port side, and the first and second flow path of the drain oil passage and the bypass oil passage from the first to respectively open and close the third switching valve, in configuration.

According to the first aspect of the present invention, the discharge flow rate can be varied in four stages by appropriately opening and closing each switching valve of the switching mechanism.

In order to achieve the above object, according to the second aspect of the present invention, a large-capacity pump having a discharge flow rate Q1 and a small-capacity pump having a discharge flow rate Q2 driven by a common drive source and a fluid discharge port communicating with a fluid supply destination. As a discharge flow rate control device of a pump device provided with an outlet, a switching mechanism is provided that switches the discharge flow rate from the fluid discharge port in four stages of Q1, Q2, Q1 + Q2, and Q1-Q2. Then, the switching mechanism allows the fluid discharged from the large-capacity pump discharge port to be sent to the fluid discharge port side, and the reverse flow from the fluid discharge port side to the large-capacity pump discharge port side is impossible. A second check valve capable of sending the fluid discharged from the small-capacity pump discharge port to the fluid discharge port side and not allowing back flow from the fluid discharge port side to the small-capacity pump discharge port side; A third check valve that allows fluid to flow into the small-capacity pump suction port side and cannot reverse flow from the small-capacity pump suction port side, and a large-capacity pump discharge port side of the first check valve and a large capacity A first drain oil passage communicating with the pump suction port side, a second drain oil passage communicating between the small capacity pump discharge port side of the second check valve and the upstream side of the third check valve, and the first reverse A bi-directional connection between the large-capacity pump discharge port side of the stop valve and the small-capacity pump suction port side of the third check valve A scan oil passage, and the first and second flow path of the drain oil passage and the bypass oil passage from the first to respectively open and close and a third switching valve.

According to the second aspect of the present invention, the discharge flow rate of the pump device can be varied in four stages by appropriately opening and closing each switching valve of the switching mechanism.

  According to the pump device and the discharge flow rate control device of the present invention, the discharge flow rate to the fluid supply destination can be varied in four stages. For this reason, even when the liquid supply destination has various types of operation members and operation mechanisms having different required liquid amounts, or when finer discharge flow rate control is required, it is possible to take flexible measures.

  In addition, it is possible to further increase the number of stages by using inexpensive parts such as check valves and switching valves without using expensive parts such as a conventional four-way valve. ing.

  Furthermore, a third check valve is provided on the small capacity pump suction port side, and a bypass oil passage and a third switching valve are provided between the large capacity pump discharge port side and the small capacity pump suction port side of the third check valve. Since it is deployed, the small-capacity pump can suck the discharge fluid of the large-capacity pump when the third switching valve is open. For this reason, in such a state, the pump driving loss can be reduced.

  Hereinafter, embodiments of a pump device and a discharge flow rate control device thereof according to the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments.

  A pump device and a discharge flow rate control device according to a first embodiment of the present invention will be described with reference to FIGS. This pump device supplies fluid to a fluid supply destination connected to the fluid discharge port 13a. Here, in the first embodiment, oil is exemplified as the fluid, and the oil pressure and the oil amount are supplied from the oil discharge port 13a as the fluid discharge port to the oil supply destination (hydraulic circuit system or the like) as the fluid supply destination. An example of the case will be described.

  First, the configuration of the pump device according to the first embodiment will be described with reference to FIG.

  Reference numeral 10 in FIG. 1 indicates the pump device of the first embodiment. The pump device 10 includes a first oil pump 1 having a discharge flow rate Q1 and a second oil pump 2 having a discharge flow rate Q2 as oil supply sources.

  Here, the first and second oil pumps 1 and 2 are driven by a common drive source 3 via a drive shaft 31. As the drive source 3, various things, such as motors, such as an internal combustion engine, and an electric motor, can be considered. Further, the drive shaft 31 may be directly connected to the output shaft (not shown) of the drive source 3 and connected via the output shaft, a pulley, a belt, a gear, a chain, or the like. May be.

  The first and second oil pumps 1 and 2 of the first embodiment are fixed capacity pumps that discharge oil having a flow rate substantially proportional to the rotational speed Ne of the drive source 3. In the control unit 8 to be described later, a correspondence relationship between the discharge flow rates Q1 and Q2 of the first and second oil pumps 1 and 2 and the rotational speed Ne of the drive source 3 is prepared in advance as an oil pump map.

  Here, the first oil pump 1 according to the first embodiment functions as a main pump mainly responsible for supplying the hydraulic pressure and the oil amount in the pump device 10, and the discharge flow rate Q 1 is discharged from the second oil pump 2. It is set to be larger than the flow rate Q2. That is, in this pump device 10, the first oil pump 1 functions as a large capacity pump, and the second oil pump 2 functions as a small capacity pump.

  For example, when the oil supply destination of the pump device 10 is an automatic transmission such as a belt type continuously variable transmission in an automobile, the discharge is performed when the drive source 3 is in the normal rotation range (for example, 1000 to 2000 rpm in the case of an internal combustion engine). When the first oil pump 1 is set so that the flow rate Q1 becomes necessary and sufficient with respect to the required flow rate in the automatic transmission, and when a large amount of oil is required such as sudden shift, the discharge flow rate “Q1 + Q2” Therefore, the first and second oil pumps 1 and 2 are set so as to be necessary and sufficient.

  Next, various oil passages are formed in the pump device 10 with the first and second oil pumps 1 and 2 as the center.

  First, the oil passage provided on the first oil pump (large capacity pump) 1 side will be described.

  On the first oil pump 1 side, a suction oil passage 11 is provided at the suction port (large capacity pump suction port). The suction oil passage 11 communicates with the oil tank 5 via the strainer 4, whereby the first oil pump 1 can suck oil from the oil tank 5.

  Further, a first discharge oil passage 12 is provided at the discharge port (large-capacity pump discharge port) on the first oil pump 1 side, and the first discharge oil passage 12 opens the first check valve 6A. Via the second discharge oil passage 13.

  Here, the first check valve 6A includes a port 6a that connects the first discharge oil passage 12 and the second discharge oil passage 13, a valve body 6b that opens and closes the port 6a, and a valve body 6b that is closed. And an elastic member (not shown) for urging in the valve direction.

  A pressing force corresponding to the hydraulic pressure of the first discharge oil passage 12 acts on the valve body 6b of the first check valve 6A, while the elastic force is directed in the opposite direction (here, the lower side of the drawing in FIG. 1). The biasing force of the member and the pressing force corresponding to the hydraulic pressure of the second discharge oil passage 13 act. Therefore, the opening / closing operation of the port 6a by the valve body 6b is controlled in accordance with the magnitude relationship between the bidirectional forces applied to the valve body 6b.

  For example, when first and third switching valves 7A and 7C, which will be described later, are closed, the hydraulic pressure of the first discharge oil passage 12 rises, and the pressing force corresponding to this hydraulic pressure is the urging force of the elastic member. It becomes larger than the resultant force with the pressing force corresponding to the hydraulic pressure of the second discharge oil passage 13. For this reason, the valve body 6b moves in the direction of opening the port 6a (here, the upper side in FIG. 1), so that the first check valve 6A is opened and the first oil pump 1 to the first discharge oil passage. The oil discharged to 12 flows into the second discharge oil passage 13 and is supplied from the oil discharge port 13a to the oil supply destination.

  In the first embodiment, the first check valve 6A provided with an elastic member is illustrated, but the elastic member is not necessarily provided. The same applies to second and third check valves 6B and 6C described later.

  Further, on the first oil pump 1 side, a first drain oil passage 14 is provided for communicating the suction oil passage 11 and the first discharge oil passage 12. The first drain oil passage 14 drains oil from the first discharge oil passage 12 discharged from the first oil pump 1 to the suction oil passage 11.

  Here, the first drain oil passage 14 is provided with a first switching valve 7A for switching the open / close state of the flow passage.

  Next, the oil passage provided on the second oil pump (small capacity pump) 2 side will be described.

  On the second oil pump 2 side, a first suction oil passage 15 is provided at the suction port (small-capacity pump suction port), and further, a second suction oil passage communicating with the first suction oil passage 15 is provided. 16 is provided. In the first embodiment, since the second suction oil passage 16 communicates with the suction oil passage 11 of the first oil pump 1, the second oil pump 2 may suck oil from the oil tank 5. it can.

  Further, on the second oil pump 2 side, a first discharge oil passage 17 is provided at the discharge port (small-capacity pump discharge port), and further, a second discharge communicating with the first discharge oil passage 17 is provided. An oil passage 18 is provided. In the first embodiment, the second discharge oil passage 18 communicates with the second discharge oil passage 13. For this reason, the oil discharged from the second oil pump 2 can be allowed to flow into the second discharge oil passage 13, and the oil can be supplied to the oil supply destination.

  Here, a second check valve 6B shown in FIG. 1 is connected between the first discharge oil passage 17 and the second discharge oil passage 18.

  The second check valve 6B is a control valve that controls the communication state between the first discharge oil passage 17 and the second discharge oil passage 18 by respective hydraulic pressures, and is the same as the first check valve 6A. Are provided with a port 6a, a valve body 6b and an elastic member (not shown).

A pressing force corresponding to the hydraulic pressure of the first discharge oil passage 17 acts on the valve body 6b of the second check valve 6B, while the elastic member is directed in the opposite direction (here, the lower side of the drawing in FIG. 1). The urging force and the pressing force corresponding to the hydraulic pressure of the second discharge oil passage 18 act. For this reason, the communication state between the first discharge oil passage 17 and the second discharge oil passage 18 is controlled according to the magnitude relationship between the bidirectional forces applied to the valve body 6b.
Further, a third check valve 6 </ b> C shown in FIG. 1 is connected between the first suction oil passage 15 and the second suction oil passage 16.

  The third check valve 6C is a control valve that controls the communication state between the first suction oil passage 15 and the second suction oil passage 16 by respective hydraulic pressures, and is the first or second check valve. Similar to the valves 6A and 6B, a port 6a, a valve body 6b and an elastic member (not shown) are provided.

  A pressing force corresponding to the hydraulic pressure of the second suction oil passage 16 acts on the valve body 6b of the third check valve 6C, while the elastic member is directed in the opposite direction (here, the lower side of the drawing in FIG. 1). The urging force and the pressing force corresponding to the hydraulic pressure of the first suction oil passage 15 act. For this reason, the communication state between the first suction oil passage 15 and the second suction oil passage 16 is controlled according to the magnitude relationship between the bidirectional forces applied to the valve body 6b.

  Further, on the second oil pump 2 side, a second drain oil passage 19 that connects the second suction oil passage 16 and the first discharge oil passage 17 is provided. The second drain oil passage 19 drains the oil discharged from the second oil pump 2 to the first discharge oil passage 17 to the second suction oil passage 16.

  Even in the second drain oil passage 19, a second switching valve 7 </ b> B for switching the open / close state of the flow passage is interposed in the same manner as the first drain oil passage 14 described above.

  Here, in the pump device 10 of the first embodiment, a bypass oil passage that bypasses between the first discharge oil passage 12 on the first oil pump 1 side and the first suction oil passage 15 on the second oil pump 2 side. 20 and a third switching valve 7 </ b> C for switching the open / close state of the bypass oil passage 20.

  In the pump device 10 of the first embodiment, the discharge flow rate in the pump device is described by the various oil passages 11 to 20, the first to third check valves 6A to 6C, and the first to third switching valves 7A to 7C. The switching mechanism is configured. This switching mechanism switches the discharge flow rate from the oil discharge port 13a by appropriately switching the open / close states of the first to third switching valves 7A to 7C.

  Here, the switching mechanism of the first embodiment is controlled by the control unit 8, and the switching mechanism and the control unit 8 constitute a discharge flow rate control device that varies the discharge flow rate of the pump device.

  The control unit 8 of the first embodiment has a function of appropriately opening and closing the first to third switching valves 7A to 7C of the switching mechanism based on the required oil amount information at the oil supply destination. Oil with a discharge flow rate corresponding to the amount information is discharged from the oil discharge port 13a.

  In the first embodiment, the discharge flow rate is switched to four stages of flow rate “Q1 + Q2”, flow rate Q1, flow rate Q2, and flow rate “Q1-Q2” as described later. From this, it can be said that the pump apparatus 10 of the first embodiment is a variable displacement pump capable of discharging oil at four stages of flow rates.

  Here, the required oil amount information may be acquired directly from the oil supply destination, or may be calculated from other information input to the control unit 8. For example, when the oil supply destination is an automobile automatic transmission, the other information in the latter includes the rotational speed Ne of the drive source 3 such as an internal combustion engine inputted to the control unit (the ECU of the automobile) 8, the automatic transmission This refers to required oil amount calculation information such as the gear ratio, the input torque of the drive source 3, and information (information obtained from the acceleration sensor) indicating the traveling state of the vehicle such as traveling on a rough road.

  The control unit 8 includes a microcomputer or the like having an arithmetic processing unit (CPU or MPU) (not shown), a storage device (RAM and ROM), and an input / output interface.

  Hereinafter, the operation of the pump device 10 according to the first embodiment will be described.

  When the control unit 8 according to the first embodiment acquires or calculates the required oil amount information at the oil supply destination, the control unit 8 appropriately opens and closes the first to third switching valves 7A to 7C based on the acquired oil amount information. A corresponding amount of oil is discharged from the oil discharge port 13a.

  Here, for example, if the drive source 3 is prepared as a dedicated one for driving the pump device 10, the controller 8 instructs the drive source 3 to start driving or output (rotation speed) control. Etc., and drive control of the drive source 3 is also performed.

  First, when the oil of the maximum flow rate “Q1 + Q2” is discharged to the pump device 10, the control unit 8 closes all the first to third switching valves 7A to 7C as shown in FIG.

  As a result, the first oil pump 1 sucks oil from the oil tank 5 and discharges the oil having the flow rate Q1 to the first discharge oil passage 12. At that time, the second oil pump 2 also sucks the oil from the oil tank 5 and discharges the oil having the flow rate Q2 to the first discharge oil passage 17.

  Here, since the first and third switching valves 7A and 7C are in the closed state, the first check valve 6A is opened by the hydraulic pressure of the oil having the flow rate Q1 discharged to the first discharge oil passage 12. And flows into the second discharge oil passage 13. Further, since the second switching valve 7B is in the closed state, the oil having the flow rate Q2 discharged to the first discharge oil passage 17 opens the second check valve 6B by the hydraulic pressure, and the second discharge oil passage. 18 and the second discharge oil passage 13 on the first oil pump 1 side.

  As described above, when the control unit 8 closes all the first to third switching valves 7A to 7C, the pump device 10 according to the first embodiment causes the oil having the maximum flow rate “Q1 + Q2” to be supplied from the oil discharge port 13a. Discharge.

  Next, the operation when the pump device 10 discharges oil at the flow rate Q1 will be described. In this pump device 10, the opening / closing operation of the two types of first to third switching valves 7A to 7C, specifically, the first and second switching valves 7A and 7B shown in FIG. The oil at the flow rate Q1 is discharged depending on whether the 3 switching valve 7C is in the opened state or the first and third switching valves 7A and 7C shown in FIG. 6 are closed and the second switching valve 7B is opened. be able to.

  In the first embodiment, as described later, in the case of “(discharge flow rate Q1) / 2 <(discharge flow rate Q2)” and “(discharge flow rate Q1) / 2> (discharge flow rate Q2)”. The above two types of opening and closing operations are used properly.

  First, when the control unit 8 closes the first and second switching valves 7A and 7B and opens the third switching valve 7C, the first oil pump 1 sucks oil from the oil tank 5, Oil at a flow rate Q1 is discharged to the first discharge oil passage 12.

  Here, since the third switching valve 7 </ b> C is in the open state, the hydraulic pressure in the first discharge oil passage 12 is also applied to the first suction oil passage 15 on the second oil pump 2 side via the bypass oil passage 20. Since this hydraulic pressure is higher than the hydraulic pressure of the second suction oil passage 16, the third check valve 6C is closed. For this reason, the second oil pump 2 sucks oil from the first discharge oil passage 12 on the first oil pump 1 side, and discharges the oil at the flow rate Q2 to the first discharge oil passage 17.

  Thus, since the hydraulic pressure of the discharge oil of the first oil pump 1 having a high hydraulic pressure is applied to the first suction oil passage 15 of the second oil pump 2, compared with the case of directly sucking oil from the oil tank 5. The second oil pump 2 can suck the oil efficiently and can reduce the pump driving loss.

  The oil with the flow rate Q2 discharged to the first discharge oil passage 17 opens the second check valve 6B and discharges the second discharge oil passage 18 in the same manner as when the oil with the flow rate “Q1 + Q2” is discharged. And flows into the second discharge oil passage 13 on the first oil pump 1 side.

  Further, in the first discharge oil passage 12, the first switching valve 7A is in a closed state, and further, the oil at the flow rate Q2 out of the oil at the flow rate Q1 is diverted through the bypass oil passage 20. A hydraulic pressure corresponding to the flow rate of “Q1-Q2” is applied to the valve body 6b of the check valve 6A. Therefore, the oil having the flow rate “Q1-Q2” flows into the second discharge oil passage 13 by opening the first check valve 6A.

  In this way, the control unit 8 closes the first and second switching valves 7A and 7B and opens the third switching valve 7C, so that the pump device 10 of the first embodiment has an oil flow rate Q1. From the oil discharge port 13a.

  Subsequently, when the control unit 8 closes the first and third switching valves 7A and 7C and opens the second switching valve 7B, the first oil pump 1 sucks oil from the oil tank 5. Then, the oil having the flow rate Q1 is discharged to the first discharge oil passage 12. At that time, in the second oil pump 2, since the third switching valve 7 </ b> C is in the closed state, the oil is similarly sucked from the oil tank 5 and discharged at the flow rate Q <b> 2 to the first discharge oil passage 17.

  Here, when the first and third switching valves 7A and 7C are in a closed state, the oil having the flow rate “Q1 + Q2” is discharged from the oil having the flow rate Q1 discharged to the first discharge oil passage 12. And flows into the second discharge oil passage 13 in the same manner. Further, the oil having the flow rate Q2 discharged to the first discharge oil passage 17 is drained to the second suction oil passage 16 via the second drain oil passage 19 because the second switching valve 7B is in the open state. . Therefore, only the oil having the flow rate Q1 from the first oil pump 1 is sent to the second discharge oil passage 13.

  As described above, the control device 8 closes the first and third switching valves 7A and 7C and also opens the second switching valve 7B, so that the pump device 10 of the first embodiment has the flow rate Q1. Oil can be discharged from the oil discharge port 13a.

  Next, when the oil of the flow rate Q2 is discharged to the pump device 10, the control unit 8 opens the first and third switching valves 7A and 7C and the second switching valve 7B as shown in FIG. Is closed.

  As a result, the first oil pump 1 sucks oil from the oil tank 5 and discharges the oil having the flow rate Q1 to the first discharge oil passage 12.

  Here, since the third switching valve 7C is in the open state, the second oil pump 2 is connected to the first oil pump 1 side in the same manner as in the case of discharging the oil at the flow rate Q1 by the method of FIG. The oil at the flow rate Q2 is sucked from the one discharge oil passage 12 and discharged to the first discharge oil passage 17. And since the 2nd switching valve 7B is a valve closing state, the oil of the flow volume Q2 opens the 2nd non-return valve 6B, and the 2nd on the 2nd discharge oil path 18 and the 1st oil pump 1 side. It flows into the discharge oil passage 13.

  For this reason, even in such a case, the second oil pump 2 can efficiently suck in the oil, so that the pump driving loss can be reduced.

  In addition, since the first switching valve 7A is also in the open state on the first oil pump 1 side, the first check valve 6A is in the closed state, and the flow rate “after the diversion in the first discharge oil passage 12”. The oil of “Q1-Q2” is drained to the suction oil passage 11 via the first drain oil passage 14.

  As described above, the control unit 8 opens the first and third switching valves 7A and 7C and closes the second switching valve 7B, so that the pump device 10 of the first embodiment has the flow rate Q2. Oil is discharged from the oil discharge port 13a.

  In such a case, all the necessary flow rate required by the oil supply destination can be satisfied with only the small-capacity second oil pump 2, and therefore the surplus flow rate “Q1-Q2” discharged from the large-capacity first oil pump 1. By draining this oil, the first oil pump 1 becomes unloaded and the pump drive loss can be effectively reduced.

  Here, in the pump device 10, the control unit 8 opens the first switching valve 7A and also closes the second and third switching valves 7B and 7C, so that the oil at the flow rate Q2 is oiled. It can be discharged from the discharge port 13a.

  In other words, in the open / close state of the first to third switching valves 7A to 7C, the oil having the flow rate Q1 discharged from the first oil pump 1 to the first discharge oil passage 12 passes through the first drain oil passage 14. Since the second switching valve 7B is in the closed state, the oil of the flow rate Q2 that is drained to the suction oil passage 11 and sucked from the oil tank 5 by the second oil pump 2 and discharged to the first discharge oil passage 17 is 2 flows into the second discharge oil passage 13 on the first oil pump 1 side via the check valve 6B and the second discharge oil passage 18. For this reason, even if the first to third switching valves 7A to 7C are opened and closed as described above, the pump device 10 can discharge the oil at the flow rate Q2 from the oil discharge port 13a.

  Even in such a case, the first oil pump 1 is unloaded, so that the pump drive loss can be reduced.

  Next, when the oil of the flow rate “Q1-Q2” is discharged to the pump device 10, the control unit 8 closes the first switching valve 7A and the second and third switching valves as shown in FIG. The valves 7B and 7C are opened.

  As a result, the first oil pump 1 sucks oil from the oil tank 5 and discharges the oil having the flow rate Q1 to the first discharge oil passage 12.

  The oil at the flow rate Q2 in the oil at the flow rate Q1 in the first discharge oil passage 12 is the bypass oil passage as in the case of discharging the oil at the flow rate Q1 or the flow rate Q2 (in the case of FIG. 3 or FIG. 4). 20 is pumped to the first suction oil passage 15 on the second oil pump 2 side.

  For this reason, even in such a case, the second oil pump 2 can efficiently suck in the oil, so that the pump driving loss can be reduced.

  Further, the oil with the flow rate “Q1-Q2” after the diversion in the first discharge oil passage 12 flows into the second discharge oil passage 13 as in the case of discharging the oil with the flow rate Q1 by the method of FIG. 3 described above. To do.

  Here, since the second switching valve 7B is opened, the second check valve 6B is closed, and the oil of the flow rate Q2 pressure-fed to the first suction oil passage 15 is the first discharge oil passage 17 and The oil is drained to the second suction oil passage 16 through the second drain oil passage 19.

  From this, the control unit 8 closes the first switching valve 7A and opens the second and third switching valves 7B and 7C, whereby the pump device 10 of the first embodiment has the flow rate “Q1− Q2 "oil is discharged from the oil discharge port 13a.

  In this case, the second oil pump 2 functions not as a hydraulic pump but as a hydraulic motor. For this reason, it can also contribute to power reduction of the first oil pump 1 driven on the same drive shaft 31.

  As described above, the pump device 10 according to the first embodiment can switch the oil discharge flow rate in four stages: the flow rate “Q1 + Q2”, the flow rate Q1, the flow rate Q2, and the flow rate “Q1-Q2”. Thus, even when the oil supply destination has various types of operation members and operation mechanisms having different required oil amounts, or when finer discharge flow rate control is required, it is possible to take a flexible response. it can.

  Here, when the required amount of oil requested by the oil supply destination is sequentially reduced, the control unit 8 may control the first to third switching valves 7A to 7C as follows.

[(Discharge flow rate Q1) / 2 <(Discharge flow rate Q2)]
Here, a case where the relationship between the discharge flow rate Q1 of the first oil pump 1 and the discharge flow rate Q2 of the second oil pump 2 is set to be “(discharge flow rate Q1) / 2 <(discharge flow rate Q2)”. Illustrate.

  In such a case, the required oil amount requested by the oil supply destination decreases in the order of flow rate “Q1 + Q2” → flow rate Q1 → flow rate Q2 → flow rate “Q1−Q2”.

  First, in such a case, as shown in FIG. 2, the control unit 8 closes all the first to third switching valves 7A to 7C and discharges the oil having the maximum flow rate “Q1 + Q2” from the oil discharge port 13a.

  Next, the control unit 8 opens only the third switching valve 7C as shown in FIG. Thereby, the pump apparatus 10 discharges the oil of the flow volume Q1 from the oil discharge port 13a as mentioned above.

  Subsequently, the control unit 8 opens the first switching valve 7A as shown in FIG. Thereby, this pump apparatus 10 discharges the oil of the flow volume Q2 from the oil discharge port 13a as mentioned above.

  Finally, as shown in FIG. 5, the control unit 8 closes the first switching valve 7A and opens the second switching valve 7B. As a result, the pump device 10 discharges the oil having the minimum flow rate “Q1-Q2” from the oil discharge port 13a as described above.

  By opening and closing the first to third switching valves 7A to 7C in this order, the pump device 10 sets the discharge flow rate in the order of flow rate “Q1 + Q2” → flow rate Q1 → flow rate Q2 → flow rate “Q1-Q2”. Decrease.

  In the pump device 10 according to the first embodiment, the control unit 8 performs opening / closing operation control of the first to third switching valves 7A to 7C in the order as described above, so that the control unit 8 controls the first to third switching valves. The discharge flow rate corresponding to the required amount of oil requested by the oil supply destination can be sequentially reduced while minimizing the number of opening / closing commands to 7A to 7C. Furthermore, since the number of opening / closing commands can be minimized, the response when switching the discharge flow rate can be improved.

  In addition, since the pump device 10 opens and closes the first to third switching valves 7A to 7C in the order as described above, the required oil amount of the oil supply destination can be reduced while minimizing the number of switching times. The corresponding discharge flow rate can be decreased sequentially. Further, since the number of operations of the first to third switching valves 7A to 7C can be minimized, the response when switching the discharge flow rate is improved and the durability of the first to third switching valves 7A to 7C is improved. The number of years can be improved.

  As described above, the pump device 10 of the first embodiment allows the control unit 8 to perform the opening / closing operation control of the first to third switching valves 7A to 7C as described above, in other words, as described above. By opening and closing the first to third switching valves 7A to 7C in order, the pump functions as a continuously variable displacement pump that is excellent in discharge response and service life while reducing pump drive loss.

  Furthermore, the pump device 10 can be further multi-staged with inexpensive parts without using expensive parts such as a four-way valve as in the prior art.

  Here, when the required amount of oil requested by the oil supply destination increases sequentially, the control unit 8 may perform opening / closing control of the first to third switching valves 7A to 7C in the reverse order (FIG. 5 → FIG. 4 → FIG. 3 → FIG. 2).

[When (Discharge flow rate Q1) / 2> (Discharge flow rate Q2)]
Next, a case where the relationship between the discharge flow rate Q1 of the first oil pump 1 and the discharge flow rate Q2 of the second oil pump 2 is set to be “(discharge flow rate Q1) / 2> (discharge flow rate Q2)”. Illustrate.

  In this case, the required amount of oil requested by the oil supply destination decreases in the order of flow rate “Q1 + Q2” → flow rate Q1 → flow rate “Q1−Q2” → flow rate Q2.

  Here, the control unit 8 first closes all the first to third switching valves 7A to 7C as shown in FIG. 2 as in the case of (discharge flow rate Q1) / 2 <(discharge flow rate Q2) described above. The oil is discharged at the maximum flow rate “Q1 + Q2” from the oil discharge port 13a.

  Next, the control unit 8 opens only the second switching valve 7B as shown in FIG.

  In the open / close state of the first to third switching valves 7A to 7C, the first oil pump 1 continuously discharges the oil of the flow rate Q1 sucked from the oil tank 5 to the first discharge oil passage 12, Oil having a flow rate Q1 is sent to the second discharge oil passage 13. Further, the second oil pump 2 continuously discharges the oil having the flow rate Q2 sucked from the oil tank 5 to the first discharge oil passage 17.

  Here, since the second switching valve 7B is in the open state, the oil having the flow rate Q2 in the first discharge oil passage 17 is drained to the second suction oil passage 16 through the second drain oil passage 19.

  For this reason, since only the oil of the flow rate Q1 from the first oil pump 1 is sent to the second discharge oil passage 13, the oil of the flow rate Q1 is discharged from the oil discharge port 13a to the oil supply destination.

  Subsequently, the control unit 8 opens the third switching valve 7C as shown in FIG. 5 to discharge the oil at the flow rate “Q1-Q2” from the oil discharge port 13a, and finally, as shown in FIG. The first switching valve 7A is opened and the second switching valve 7B is closed to discharge the oil having the minimum flow rate Q2 from the oil discharge port 13a.

  By opening and closing the first to third switching valves 7A to 7C in this order, the pump device 10 decreases the discharge flow rate in the order of flow rate “Q1 + Q2” → flow rate Q1 → flow rate “Q1-Q2” → flow rate Q2. Let

  Even in the pump device 10 in such a case, the same effect as in the case of (discharge flow rate Q1) / 2 <(discharge flow rate Q2) described above can be obtained, and further, the discharge response can be reduced while reducing the pump drive loss. It functions as a continuously variable displacement pump with excellent service life.

  Here, in the case of (discharge flow rate Q1) / 2> (discharge flow rate Q2), and when the required oil amount requested by the oil supply destination increases sequentially, the controller 8 performs the reverse operation in the reverse order. The opening / closing control of the first to third switching valves 7A to 7C may be performed (FIG. 4 → FIG. 5 → FIG. 6 → FIG. 2).

  In the first embodiment, oil is exemplified as the fluid, but the fluid to be applied may be another liquid such as water or a gas such as air.

  Next, a second embodiment of the pump device and its discharge flow rate control device according to the present invention will be described with reference to FIG.

  The code | symbol 110 of FIG. 7 shows the pump apparatus of the present Example 2. FIG. In this pump device 110, the first and second oil pumps 1 and 2 are driven by separate drive sources 103A and 103B, respectively, and this point is different from the pump device 10 of the first embodiment. In the following, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the pump device 110 according to the second embodiment, the discharge flow rate is switched by the control unit 8 as in the first embodiment.

  In addition, here, the drive sources 103A and 103B are illustrated as being prepared exclusively for driving the pump device 110. For this reason, the control unit 8 has a function of transmitting a drive start command, an output (rotation speed) control command, and the like to each of the drive sources 103A and 103B and performing drive control thereof.

  First, when the oil of the maximum flow rate “Q1 + Q2” is discharged to the pump device 110, the control unit 8 closes all the first to third switching valves 7A to 7C and drives the driving sources 103A and 103B. Let Thereby, this pump apparatus 110 discharges oil of the maximum flow rate “Q1 + Q2” from the oil discharge port 13a in the same manner as in the first embodiment.

  When the pump device 110 is made to discharge the oil at the flow rate Q1, the control unit 8 closes all the first to third switching valves 7A to 7C, and only the driving source 103A of the first oil pump 1 is closed. Drive.

  As a result, the first oil pump 1 sucks oil from the oil tank 5 and discharges the oil having the flow rate Q1 to the first discharge oil passage 12. Here, since the first and third switching valves 7A and 7C are in the closed state, the oil having the flow rate Q1 discharged to the first discharge oil passage 12 flows into the second discharge oil passage 13 and discharges the oil. It is discharged from the outlet 13a.

  When the respective drive sources 103A and 103B are driven, the first to third switching valves 7A to 7C are opened and closed in the same manner as in the first embodiment, so that the oil at the flow rate Q1 is discharged. You may make it discharge from the exit 13a.

  When the pump device 110 is made to discharge the oil at the flow rate Q2, the control unit 8 closes all the first to third switching valves 7A to 7C, and only the drive source 103B of the second oil pump 2 is used. Drive.

  As a result, the second oil pump 2 sucks oil from the oil tank 5 and discharges the oil having the flow rate Q2 to the first discharge oil passage 17. Here, since the second switching valve 7B is in the closed state, the oil of the flow rate Q2 discharged to the first discharge oil passage 17 is the second discharge oil on the second discharge oil passage 18 and the first oil pump 1 side. It flows into the channel 13 and is discharged from the oil discharge port 13a.

  When each of the drive sources 103A and 103B is driven, the first to third switching valves 7A to 7C are opened and closed in the same manner as in the first embodiment, so that the oil at the flow rate Q2 is discharged. You may make it discharge from the exit 13a.

  Further, when the oil of the flow rate “Q1-Q2” is discharged to the pump device 110, the control unit 8 closes the first switching valve 7A and opens the second and third switching valves 7B, 7C. Further, the drive sources 103A and 103B are driven. Thereby, this pump apparatus 110 discharges the oil of the flow rate “Q1-Q2” from the oil discharge port 13a as in the first embodiment.

  As described above, even in the second embodiment, the oil discharge flow rate can be switched in four stages: the flow rate “Q1 + Q2”, the flow rate Q1, the flow rate Q2, and the flow rate “Q1-Q2”.

  Here, also about the pump apparatus 110 of this Example 2, the operation | movement when the required oil amount which an oil supply destination requests | requires reduces sequentially is demonstrated.

[(Discharge flow rate Q1) / 2 <(Discharge flow rate Q2)]
First, when the relationship between the discharge flow rate Q1 of the first oil pump 1 and the discharge flow rate Q2 of the second oil pump 2 is set to be “(discharge flow rate Q1) / 2 <(discharge flow rate Q2)”, the control is performed. The unit 8 closes all the first to third switching valves 7A to 7C and drives the drive sources 103A and 103B to discharge the oil having the maximum flow rate “Q1 + Q2” from the oil discharge port 13a.

  Subsequently, the control unit 8 stops the drive source 103B of the second oil pump 2 to discharge the oil of the flow rate Q1 from the oil discharge port 13a, and then drives the drive source 103B and the first oil pump. 1 drive source 103A is stopped, and oil with a flow rate Q2 is discharged from the oil discharge port 13a.

  Finally, the control unit 8 opens the second and third switching valves 7B and 7C, and drives the drive source 103A of the first oil pump 1 so that the minimum flow rate “Q1− Q2 "oil is discharged.

  In this way, the pump device 110 can reduce the discharge flow rate in the order of the flow rate “Q1 + Q2” → the flow rate Q1 → the flow rate Q2 → the flow rate “Q1−Q2”.

[When (Discharge flow rate Q1) / 2> (Discharge flow rate Q2)]
Next, when the relationship between the discharge flow rate Q1 of the first oil pump 1 and the discharge flow rate Q2 of the second oil pump 2 is set to be “(discharge flow rate Q1) / 2> (discharge flow rate Q2)”, The controller 8 discharges the oil having the maximum flow rate “Q1 + Q2” from the oil discharge port 13a in the same manner as in the case of (discharge flow rate Q1) / 2 <(discharge flow rate Q2) described above.

  Subsequently, the control unit 8 stops the drive source 103B of the second oil pump 2 to discharge the oil at the flow rate Q1 from the oil discharge port 13a, and then drives the drive source 103B and performs the second and second operations. 3 switching valves 7B and 7C are opened, and the oil of the flow rate “Q1-Q2” is discharged from the oil discharge port 13a.

  Finally, the control unit 8 closes the second and third switching valves 7B and 7C and stops the drive source 103A of the first oil pump 1 to discharge the oil at the flow rate Q2 from the oil discharge port 13a. Let

  In this way, the pump device 110 can reduce the discharge flow rate in the order of the flow rate “Q1 + Q2” → the flow rate Q1 → the flow rate “Q1−Q2” → the flow rate Q2.

  As described above, even when the driving sources 103A and 103B are prepared exclusively for driving the pump device 110, the number of operations of the first to third switching valves 7A to 7C can be suppressed. 1 can be obtained.

  Here, when one of the drive sources 103A and 103B is prepared exclusively for driving the pump device 110 and the other is driven by a prime mover such as an internal combustion engine, the pump device 110 operates as follows. Here, a case where the drive source 103A of the first oil pump 1 is a prime mover is illustrated.

  First, when the oil of the maximum flow rate “Q1 + Q2” is discharged to the pump device 110, the control unit 8 closes all the first to third switching valves 7A to 7C and drives the drive source 103B of the second oil pump 2. Drive. Thereby, this pump apparatus 110 discharges oil of the maximum flow rate “Q1 + Q2” from the oil discharge port 13a in the same manner as in the first embodiment.

  Further, when the pump device 110 discharges oil at the flow rate Q1, the control unit 8 closes all the first to third switching valves 7A to 7C and stops the drive source 103B of the second oil pump 2. Let Thereby, the oil of the flow volume Q1 is discharged from the oil discharge port 13a similarly to the case where both of the drive sources 103A and 103B described above are driven and controlled by the control unit 8.

  When the pump device 110 discharges oil at the flow rate Q2, the control unit 8 opens the first and third switching valves 7A and 7C and drives only the drive source 103B of the second oil pump 2. Let Thereby, the oil of the flow volume Q2 is discharged from the oil discharge port 13a similarly to the case shown in FIG. 4 of the first embodiment.

  Further, when the oil of the flow rate “Q1-Q2” is discharged to the pump device 110, the control unit 8 closes the first switching valve 7A and opens the second and third switching valves 7B, 7C. Further, the drive source 103B of the second oil pump 2 is driven. Thereby, this pump apparatus 110 discharges the oil of the flow rate “Q1-Q2” from the oil discharge port 13a in the same manner as when both the drive sources 103A and 103B are driven and controlled by the control unit 8. .

  In this way, even in such a case, the oil discharge flow rate can be switched in four stages: flow rate “Q1 + Q2”, flow rate Q1, flow rate Q2, and flow rate “Q1-Q2”.

  Here, even when such one (here, the first oil pump 1) is driven by the prime mover, when the required oil amount requested by the oil supply destination decreases sequentially, the required oil amount depends on the required oil amount. In addition, the control unit 8 may control the operations of the first to third switching valves 7A to 7C and the second oil pump 2 in order so that the above-described discharge flow rate is obtained. It becomes possible to play.

  As described above, the pump device and the discharge flow rate control device according to the present invention are useful for multi-stage discharge flow rate, and in particular, reduce the pump drive loss while providing multi-stage with an inexpensive configuration. Suitable for

It is a figure explaining the structure of Example 1 of the pump apparatus which concerns on this invention, and its discharge flow control apparatus. It is a figure which shows the opening-and-closing state of the 1st-3rd switching valve in case the pump apparatus of Example 1 discharges the oil of flow volume "Q1 + Q2." It is a figure which shows the opening-and-closing state of the 1st-3rd switching valve in case the pump apparatus of Example 1 discharges the oil of the flow volume Q1. It is a figure which shows the open / close state of the 1st to 3rd switching valve in case the pump apparatus of Example 1 discharges the oil of the flow volume Q2. It is a figure which shows the opening-and-closing state of the 1st-3rd switching valve in case the pump apparatus of Example 1 discharges the oil of flow volume "Q1-Q2." It is a figure which shows the other open-close state of the 1st to 3rd switching valve in case the pump apparatus of Example 1 discharges the oil of the flow volume Q1. It is a figure explaining the structure of Example 2 of the pump apparatus which concerns on this invention, and its discharge flow control apparatus.

Explanation of symbols

1 First oil pump (large capacity pump)
2 Second oil pump (small capacity pump)
3, 103A, 103B Drive source 6A 1st check valve 6B 2nd check valve 6C 3rd check valve 7A 1st switching valve 7B 2nd switching valve 7C 3rd switching valve 8 Control unit 10,110 Pump device 11 1st 1 oil pump side suction oil path 12 first oil pump side first discharge oil path 13 first oil pump side second discharge oil path 13a oil discharge port 14 first drain oil path 15 second oil pump side first 1 suction oil passage 16 second suction oil passage on the second oil pump side 17 first discharge oil passage on the second oil pump side 18 second discharge oil passage on the second oil pump side 19 second drain oil passage 20 bypass oil passage 31 Drive shaft Q1 Discharge flow rate of the first oil pump Q2 Discharge flow rate of the second oil pump

Claims (2)

A large-capacity pump that discharges fluid at a discharge flow rate Q1, a small-capacity pump that is driven by a common drive source with the large-capacity pump and discharges fluid at a discharge flow rate Q2, and a fluid discharge port that communicates with a fluid supply destination A pump device comprising:
A switching mechanism for switching the discharge flow rate from the fluid discharge port to four stages of Q1, Q2, Q1 + Q2, and Q1-Q2 ,
The switching mechanism,
A first check valve capable of delivering fluid discharged from a large capacity pump discharge port to the fluid discharge port side and not allowing back flow from the fluid discharge port side to the large capacity pump discharge port;
A second check valve capable of delivering the fluid discharged from the small-capacity pump discharge port to the fluid discharge port side and not allowing a reverse flow from the fluid discharge port side to the small-capacity pump discharge port side;
A third check valve that allows fluid to flow into the small-capacity pump suction port and prevents backflow from the small-capacity pump suction port;
A first drain oil passage communicating the large-capacity pump discharge port side and the large-capacity pump suction port side of the first check valve;
A second drain oil passage communicating the small capacity pump discharge port side of the second check valve and the upstream side of the third check valve;
A bypass oil passage communicating the large capacity pump discharge port side of the first check valve and the small capacity pump suction port side of the third check valve;
First to third switching valves for opening and closing the flow paths of the first and second drain oil passages and the bypass oil passage, respectively;
Pump apparatus characterized by being composed. A discharge flow rate control device of a pump device comprising a large capacity pump with a discharge flow rate Q1 and a small capacity pump with a discharge flow rate Q2 driven by a common drive source, and a fluid discharge port communicating with a fluid supply destination,
A switching mechanism for switching the discharge flow rate from the fluid discharge port to four stages of Q1, Q2, Q1 + Q2, and Q1-Q2,
The switching mechanism,
A first check valve capable of delivering fluid discharged from a large capacity pump discharge port to the fluid discharge port side and not allowing back flow from the fluid discharge port side to the large capacity pump discharge port;
A second check valve capable of delivering the fluid discharged from the small-capacity pump discharge port to the fluid discharge port side and not allowing a reverse flow from the fluid discharge port side to the small-capacity pump discharge port side;
A third check valve that allows fluid to flow into the small-capacity pump suction port and prevents backflow from the small-capacity pump suction port;
A first drain oil passage communicating the large-capacity pump discharge port side and the large-capacity pump suction port side of the first check valve;
A second drain oil passage communicating the small capacity pump discharge port side of the second check valve and the upstream side of the third check valve;
A bypass oil passage communicating the large capacity pump discharge port side of the first check valve and the small capacity pump suction port side of the third check valve;
First to third switching valves for opening and closing the flow paths of the first and second drain oil passages and the bypass oil passage, respectively;
A discharge flow rate control device for a pump device, comprising:

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