JP2007113757A - Generating equipment combined with drive mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pump/hydraulic motor M and a motor/generator G, and to exert independently both the functions. <P>SOLUTION: The equipment is equipped with the pump/hydraulic motor M combined and the motor/generator G which is coupled to the pump/hydraulic motor M. When a switching valve S has been switched to a generating mode, a return flow from a cylinder 1 is conducted to the pump/hydraulic motor M and a return flow from the pump/hydraulic motor M is refluxed to a tank via the switching valve. At the same time, when having switched the switching valve to an actuator drive mode, the pump/hydraulic motor which rotates with, as a drive unit, the motor/generator combined with a motor function, is allowed to suck a working oil from the tank and besides a discharged oil from the hydraulic motor combined with a pump function is supplied to an actuator. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a drive mechanism / generator that drives a hydraulic motor using inertial energy and potential energy of an actuator and that rotates a generator by the rotational force of the hydraulic motor.

As this type of apparatus, an apparatus described in Patent Document 1 has been conventionally known. This conventional device is provided with a switching valve that switches on and off in a return passage when inertial energy or potential energy acts on the actuator. When the switching valve is in the normal position, the return oil of the actuator returns to the tank via the switching valve. Further, when the switching valve is switched from the normal position to the switching position, the return oil of the actuator to which the inertia energy or the position energy is applied is guided to the hydraulic motor. A generator is connected to the hydraulic motor, and when the hydraulic motor is rotated by the return oil, the generator is rotated by the rotational force to generate electric power.
JP 2004-11168 A

  In the conventional apparatus as described above, when the switching valve is switched from the switching position to the normal position, in other words, while the switching valve is held in the switching position and the hydraulic motor is being driven, When the actuator is suddenly returned to the normal position and the actuator is returned to the normal control, negative pressure is generated on the hydraulic motor side connected to the generator. This is because even if the switching valve is switched to the normal position, the inertial energy of the hydraulic motor and the generator is large, so that they do not stop immediately. In particular, since the inertial energy of the generator is large, the hydraulic motor connected to the generator cannot be stopped suddenly, and negative pressure is generated on the suction side.

  When the suction side of the hydraulic motor becomes negative as described above, cavitation occurs there, but this cavitation causes noise and damages the sliding part of the hydraulic motor. Therefore, in order to prevent the negative pressure from being generated, for example, the switching control valve for controlling the actuator may be switched slowly, but this makes it impossible to control the actuator crisply. In any case, the conventional apparatus has a problem that cavitation is likely to occur, and if it is attempted to cover the problem with the operation capability of the operator, there is a problem that crisp control cannot be performed this time.

  Further, even if the switching valve is switched to the normal position in order to stop the hydraulic motor and the generator, the inertia energy of the generator is very large as described above, so that it does not stop easily. If it takes too much time for the hydraulic motor or generator to stop, the negative pressure on the suction side of the hydraulic motor will further increase. Therefore, when the switching valve is switched to the normal position, the hydraulic motor and the generator must be stopped quickly, but if the energy is absorbed in a short time, the generator must be enlarged.

  This is because, in order to absorb the inertial energy, the generator must absorb the energy in the form of electrical conversion. Therefore, if the energy absorption time is to be shortened, the generator must be enlarged. Because there is no. However, if the generator is increased in size, the inertial energy of the generator will increase more and more, and absorbing the inertial energy in a short time and keeping the generator small It became a contradictory relationship, and conventional devices could not solve them all at once.

  Further, when the inertial energy is applied to the actuator, the return path is connected to the hydraulic motor as described above, and the passage is returned directly to the tank via the switching control valve without being connected to the hydraulic motor. Thus, the operating speed of the actuator may be different. If the operating speeds of the actuators are different in this way, the operator is impressed as a difference in operational feeling, and there is a problem that the uncomfortable feeling deteriorates operability.

  The first invention includes a pump combined hydraulic motor and a motor combined generator connected to the pump combined hydraulic motor, and a switching valve is connected to the pump combined hydraulic motor. Of the fourth ports, the first port is connected to one side of the pump / hydraulic motor, the second port is connected to the other side of the pump / hydraulic motor, the third port is connected to the actuator, When the port is connected to the tank and the switching valve is switched to the power generation mode, the first port and the third port communicate with each other, and the second port and the fourth port communicate with each other. The return flow is guided to the pump / hydraulic motor, and the return flow discharged from the pump / hydraulic motor is returned to the tank via the switching valve. When switching to the motor drive mode, the first port and the fourth port are communicated, the second port and the third port are communicated, and the pump / hydraulic motor that rotates using the motor / generator as a drive source is connected from the tank. Leakless that allows the hydraulic oil to be sucked in and that the oil discharged from the pump / hydraulic motor to be supplied to the actuator and allows the flow from the third port in the flow path process connecting the third port actuator. It is characterized in that a valve is provided and the actuator is configured to hold a load.

  The second invention is characterized in that when the switching valve is in the neutral position, the first and third ports are closed and the second and fourth ports are communicated with each other while maintaining the throttle opening.

  According to a third aspect of the present invention, there is provided one flow path that connects the first port of the switching valve and one side of the pump / hydraulic motor, and the other port that connects the second port and the other side of the pump / hydraulic motor. A feature is that a relief valve for controlling the maximum pressure of the one channel is provided between the channels.

  The fourth invention is characterized in that a replenishment flow path is connected to one flow path connecting the first port of the switching valve and one side of the hydraulic pump and pump.

  According to a fifth aspect of the present invention, there is provided one flow path connecting the first port of the switching valve and one side of the hydraulic pump motor, and the other port connecting the second port and the other side of the hydraulic pump motor. A short-circuit channel is provided between the two channels, and this short-circuit channel is characterized in that a check valve that allows only a flow from the other channel to one channel is provided.

  The sixth invention is provided with a switching control valve for controlling the actuator, and the total flow rate of the flow rate Qt flowing through the switching control valve to the tank and the flow rate Qm flowing through the switching valve to the hydraulic motor is: It is characterized in that a control mechanism for controlling the switching control valve and the opening degree of the switching valve is provided while maintaining a relationship equal to the flow rate Qc required for the return control of the actuator.

  According to the first aspect of the invention, the pump / hydraulic motor can be used as a drive source for turning the generator or a drive source for driving the actuator.

  According to the second invention, when the switching valve is switched to the neutral position to stop the hydraulic pump motor, the throttle opening is maintained in the communication process between the second port and the fourth port. Discharged oil from the hydraulic pump and pump that continues to rotate with inertial energy is returned to the tank through the throttle opening. In this way, since the oil discharged from the pump / hydraulic motor that continues to rotate with inertial energy is returned to the tank, no shock is generated in the pump / motor when stopped.

  According to the third invention, since the first relief valve and the second relief valve are provided between the one flow path and the other flow path, when the hydraulic pump motor is used as a hydraulic motor, Even when used as a pump, the maximum pressure can be controlled by the relief valve.

  According to the fourth aspect of the invention, since the supply flow path is connected to one flow path, for example, even if the hydraulic pump motor combined with the pump is rotated by inertia energy in the state where the switching valve is switched to the neutral position, the supply flow Shortage of hydraulic fluid can be supplied from the road. Therefore, no negative pressure is generated on the one flow path side, and as a matter of course, problems such as cavitation caused by the negative pressure and damage to the pump / hydraulic motor do not occur.

  According to the fifth aspect, since one of the flow paths and the other flow path can be short-circuited when the switching valve is neutral, the hydraulic oil discharged by itself can be returned to the suction side. In addition, when the switching valve is in a neutral state, coupled with the replenishment flow path of the fourth aspect of the invention, even if the pump combined hydraulic motor and the motor combined generator continue to rotate with inertial energy, the negative pressure on the suction side of the pump combined hydraulic motor is negative. No pressure is generated. Therefore, cavitation does not occur as in the prior art, and problems such as noise and hydraulic motor damage caused by this cavitation do not occur.

  In addition, even if the switching valve is kept in the neutral position as described above, there is no problem even if each of the pump-use hydraulic motor and the motor-use generator continues to rotate with inertial energy. A generator can be selected freely. For example, if a large amount of inertial energy is to be absorbed in a short time with a conventional device, a correspondingly large generator must be used. However, since a large generator has a larger inertial energy, there is a limit to the size of the generator that can be adopted. However, according to the present invention, inertial energy can be absorbed regardless of the size of the hydraulic motor and the generator, so that the degree of freedom in design for selecting the size of the generator is greatly increased.

  According to the sixth aspect of the invention, the total flow rate of the flow rate Qt that flows through the switching control valve connected to the actuator and flows to the tank and the flow rate Qm that flows through the switching valve and flows to the pump hydraulic motor is controlled by the control mechanism. Since the flow rate is equal to the flow rate Qc required for the return control of the actuator, the switching control valve and the electromagnetic proportional switching valve are opened so that the flow rate is equal to the operating speed of the actuator when it is not necessary to supply the flow rate to the pump hydraulic motor. You can control the degree. Therefore, even when the motor / generator is driven, the operator can operate the actuator without a sense of incongruity.

  In the first embodiment shown in FIG. 1, a switching control valve 2 that is a three-position four-port valve is connected to a cylinder 1 that is an actuator of the present invention. The pump port 2a is connected to a pump P, and a tank Port 2b is connected to tank T. Further, of the pair of actuator ports 2c and 2d, one actuator port 2c is connected to the rod side chamber 1a of the cylinder 1 via the passage 3, and the other actuator port 2d is connected to the piston side chamber 1b via the passage 4. Connected.

  The switching control valve 2 configured as described above maintains all the ports 2a to 2d in a closed state when in the illustrated neutral position. When the switching control valve 2 is switched to the left position in the drawing, the pump port 2a communicates with the actuator port 2d, and the tank port 2b communicates with the actuator port 2c. Accordingly, the oil discharged from the pump P is supplied to the piston side chamber 1b of the cylinder 1 to extend the cylinder 1, and the return oil from the rod side chamber 1a is returned to the tank T. Further, when the switching control valve 2 is switched to the right position in the drawing, the piston side chamber 1b communicates with the tank T and the rod side chamber 1a communicates with the pump P, and the cylinder 1 is contracted.

  However, a leakless valve 5 is provided in the passage 4. When the back pressure control valve 6 is in the throttle position, the leakless valve 5 can freely flow from the switching control valve 2 to the piston side chamber 1b of the cylinder 1, but the back pressure control valve 6 is in the check position. The flow from the piston side chamber 1b to the switching control valve 2 is blocked. A back pressure control valve 6 is connected to the back pressure chamber 5a. The back pressure control valve 6 has a check valve position and a throttle position. Normally, the spring pressure of the spring 7 keeps the check valve position and prevents the pressure from being released from the back pressure chamber 5a. When the pilot pressure is applied to the pilot chamber 6a, the throttle chamber is switched to the throttle position, and the pressure oil in the back pressure chamber 5a is guided to the tank T through the throttle.

  In addition, the cylinder 1 in this embodiment is installed in the state which turned down the piston side chamber 1b. Therefore, when the piston side chamber 1b is communicated with the tank T and the cylinder 1 is contracted, inertial energy and potential energy act on the cylinder 1 by the load acting on the cylinder 1, and at this time, the passage 4 Is the return path. As a matter of course, when the piston side chamber 1b is communicated with the pump P, the cylinder 1 increases the load acting on it.

  The pilot control mechanism PO controls the switching control valve 2 as described above. The pilot control mechanism PO guides the pilot pressure to one of the pilot chambers 8 or 9 of the switching control valve 2 by operating the operating lever 14, and the switching control valve 2 is driven by the pilot pressure as described above. I try to switch. The pilot chamber 6a of the back pressure control valve 6 and the pilot chambers 8 and 9 of the switching control valve 2 communicate with each other via a shuttle valve. Therefore, when a pilot pressure is applied to the pilot chambers 8 and 9 of the switching control valve 2, the pilot pressure is also applied to the pilot chamber 6a of the back pressure control valve 6, and the back pressure control valve 6 is opened.

  As described above, when the cylinder 1 contracts, inertial energy and potential energy according to the load act. As described above, when inertial energy and potential energy act on the cylinder 1, the return side The connecting passage 10 is connected to a passage 4 that becomes the upstream side of the leakless valve 5 with respect to the return flow. The connection passage 10 thus configured is connected to the switching valve S via the leakless valve 11. In this leakless valve 11, from the switching valve S to the piston side chamber 1b of the cylinder 1, the pressure of the fifth port 17 is higher than the pressure obtained by adding the pressure of the connection passage 10 and the spring equivalent pressure of the leakless valve 11. It will circulate when it becomes. And if the pressure of the 5th port 17 is below the added pressure, the distribution will be blocked.

  A back pressure control valve 12 is connected to the back pressure chamber 11a. The back pressure control valve 12 has a check valve position and a throttle position, and normally the spring force of a spring 13 maintains the check valve position to prevent pressure from being released from the back pressure chamber 11a. When the pilot pressure is applied to the pilot chamber 12a, the throttle chamber is switched to the throttle position, and the pressure oil in the back pressure chamber 11a is guided to the tank T through the throttle, allowing the flow from the connection passage 10 to the switching valve S. Is.

  The switching valve S is a three-position four-port valve whose switching amount is controlled in accordance with an electrical signal. That is, the switching valve S includes first to fourth ports 15 to 18, and the first port 15 is on the supply side or the suction side with respect to the pump / hydraulic motor M that is the power source of the motor / generator G. It is connected to the first flow path 19. The second port 16 is connected to the second flow path 20 on the return side or the discharge side with respect to the pump combined hydraulic motor M, and the third port 17 is connected to the passage 4 via the leakless valve 11. The fourth port 18 is connected to the tank T via the connection passage 21.

  The switching valve S configured as described above is provided with pilot chambers 22 and 23 and centering springs 24 and 25 on both sides thereof. The one pilot chamber 22 is in communication with the pilot chamber 8 of the switching control valve 2. Therefore, when a pilot pressure is applied to the pilot chamber 8 in order to supply the discharge oil of the pump P to the piston side chamber 1b of the cylinder 1, the pilot pressure is also applied to the pilot chamber 22 of the switching valve S. The valve S is switched to the actuator drive mode which is the upper position in the drawing.

  A pilot pressure control valve 26 is connected to the other pilot chamber 23. The pilot pressure control valve 26 controls the pilot pressure according to the exciting current of the solenoid 26a. Therefore, the pilot pressure control valve 26 guides the pilot pressure corresponding to the exciting current supplied to the solenoid 26a to the pilot chamber 23, and the switching valve S is switched according to the magnitude of the pilot pressure. .

  The switching valve S configured as described above normally maintains the neutral position shown in the figure by the action of the centering springs 24 and 25. However, when the switching valve S is in the neutral position, the first and third ports 15 and 17 communicate with each other. Is closed, and the second and fourth ports 16 and 18 communicate with each other while maintaining the throttle opening. When the switching control valve 2 is switched to the left position in the drawing in order to supply the oil discharged from the pump P to the piston side chamber 1b of the cylinder 1, the switching valve S is also moved from the neutral position to the actuator at the upper position in the drawing. Switch to drive mode. Thus, when the switching valve S is switched to the actuator drive mode, the first port 15 and the fourth port 18 communicate with each other, and the second port 16 and the third port 17 communicate with each other.

  When the pilot pressure is applied to the other pilot chamber 23, the switching valve S is switched to the power generation mode, which is the lower position in the drawing, and the first port 15 and the third port 17 are communicated with each other. The 4 port 18 is connected. However, the communication opening degree of each port at this time is controlled according to the exciting current of the solenoid 26a as described above. A controller (not shown) controls the exciting current of the solenoid 26a and the operation amount of the operation lever 14 of the pilot control mechanism PO described above in synchronism. The pilot pressure control valve 26 is also connected to the pilot chamber 12 a of the back pressure control valve 12. Therefore, when the switching valve S is switched to the power generation mode, the back pressure control valve 12 is opened and the leakless valve 11 is opened.

  In addition, a short-circuit channel 27 for short-circuiting both of them is provided between the first channel 19 and the second channel 20, and the short-circuit channel 27 is opened and closed to open and close the short-circuit channel 27. A valve 28 and a check valve 29 that allows only the flow from the second flow path 20 to the first flow path 19 are provided in series. When the pilot pressure is applied to the pilot chamber 28a, the on-off valve 28 is switched against the spring 30. In the normal position, the short-circuit channel 27 is opened, and the pilot pressure is applied to the switching position. When switched to, the short-circuit channel 27 is closed. Moreover, the pilot chamber 28a of the on-off valve 28 communicates with the pilot chamber 8 for switching the switching control valve 2 to the left position in the drawing. Therefore, when the switching control valve 2 is switched to the left position in the drawing and the pump discharge oil is guided to the piston side chamber 1b of the cylinder 1, the on-off valve 28 is switched to the closed position.

  Furthermore, first and second relief valves 31 and 32 are provided between the first flow path 19 and the second flow path 20, and the first relief valve 31 increases the maximum pressure of the first flow path 19. The second relief valve 32 controls the maximum pressure of the second flow path 20. In addition, a replenishment flow path 33 is connected to the first flow path 19 so that a deficient flow rate can be sucked from the tank T. In the figure, reference numeral 34 is a check valve provided in the replenishment flow path 33, and the check valve 34 allows only the flow from the tank T to the first flow path 19.

  Next, the operation of the first embodiment will be described. Now, when the switching control valve 2 is maintained at the neutral position shown in the drawing and the operation lever 14 of the pilot control mechanism PO is operated to switch the switching control valve 2 to the right position in the drawing, the back pressure control valve 6 is also opened. Therefore, the leakless valve 11 is opened. Accordingly, the oil discharged from the pump P is supplied to the rod side chamber 1a, and the oil discharged from the piston side chamber 1b is returned to the tank T. However, at this time, a throttle 36 is formed between the actuator port 2d of the switching control valve 2 and the tank port 2b. The opening of the throttle 36 depends on the switching stroke of the switching control valve 2. To change according to

  Further, when the switching control valve 2 is switched to the right side position in the drawing as described above, the switching valve S is switched to the power generation mode which is the lower side position in the drawing. At this time, a controller (not shown) controls the excitation current supplied to the solenoid 26 a according to the switching amount of the switching control valve 2, that is, the opening degree of the throttle 36. Therefore, the switching amount of the switching valve S in the power generation mode is controlled according to the opening degree of the throttle 36, and the switching amount is controlled as follows.

  That is, the total flow rate of the flow rate Qt flowing through the switching control valve 2 and flowing into the tank T and the flow rate Qm passing through the switching valve S and supplied to the hydraulic motor M is necessary for the return control of the cylinder 1. It is made to become equal to flow rate Qc to be performed. In other words, the total amount Qc of the return flow rate from the cylinder 1 is controlled to be the total flow rate of the flow rate Qt passing through the throttle 36 and the flow rate Qm passing through the switching valve S. By controlling the flow rate in this way, the operational feeling of the cylinder 1 felt by the operator is almost different between the case where the pump combined hydraulic motor M and the motor combined generator G are provided and the case where they are not provided. The effect of disappearing can be expected.

  When the switching valve S is switched to the power generation mode as described above, the pressure oil corresponding to the pressure loss of the throttle 36 is guided to the first flow path 19, so that the pump combined hydraulic motor M rotates at that pressure. Then, the motor / generator G is turned to exhibit the power generation function. The motor / generator G is connected to a battery (not shown) so that the generated power can be stored. When the switching control valve 2 is returned to the neutral position shown in the above state, the cylinder 1 stops and a controller (not shown) functions to set the exciting current of the switching valve S to zero. Is returned to the neutral position shown in the figure.

  When the switching valve S returns to the neutral position as described above, the supply of pressure oil to the pump combined hydraulic motor M is cut off, so the pump combined hydraulic motor M attempts to stop, but the pump combined hydraulic motor M In addition, due to the inertial energy of the motor / generator G, the pump / hydraulic motor M continues to rotate until the inertial energy is absorbed. When the hydraulic motor M continues to rotate with inertial energy in this way, the pump combined hydraulic motor M substantially performs a pumping action. Therefore, the hydraulic oil is sucked from the first flow path 19 side and discharged to the second flow path 20 side. As described above, the communication between the first port 15 and the third port 17 of the switching valve S is performed. Is cut off, the combined pump hydraulic motor M cannot sufficiently suck hydraulic oil from the first flow path 19.

  However, at this time, the hydraulic oil discharged from the pump combined hydraulic motor M to the second flow path 20 side is returned to the first flow path 19 side where the pressure is low via the short circuit passage 27. In addition, since the hydraulic oil in the tank T is also supplied from the supply flow path 33, no negative pressure is generated on the suction side of the pump / hydraulic motor M, and cavitation occurs due to the negative pressure. Will be resolved.

  In addition, for example, the operation of extending or contracting the cylinder 1 may be repeated in a short time. If such an operation is repeated in a short time, the switching valve S also substantially repeats the on / off operation. become. However, although the pump combined hydraulic motor M connected to the motor combined generator G having a large inertial energy cannot be stopped and driven repeatedly in a short time, in this embodiment, the switching valve S is repeatedly turned on and off in a short time. However, the inertial energy of the generator G can be absorbed, no negative pressure is generated on the first flow path 19 side, and cavitation is not generated.

  Moreover, even if the switching valve S is suddenly switched to the neutral position shown in the figure, the second port 16 and the fourth port 18 communicate with each other while maintaining the throttle opening, so that the pump combined hydraulic motor M is shocked. Does not occur.

  On the other hand, when the switching control valve 2 is switched to the left side of the drawing and the discharge oil of the pump P is supplied to the piston side chamber 1b of the cylinder 1, the pilot pressure for switching the switching control valve 2 at that time is one of the switching valves S. Acting on the pilot chamber 22. Accordingly, at this time, the switching valve S is switched to the actuator drive mode which is the upper position in the drawing. Thus, when the switching valve S is switched to the actuator drive mode, the first port 15 and the fourth port 18 communicate with each other, so the first flow path 19 is connected to the tank via the first and fourth ports 15 and 18. It will communicate with T. In addition, since the second port 16 and the third port 17 communicate with each other, the second flow path 20 communicates with the passage 4 through the second and third ports 16 and 17. In addition, at this time, the on-off valve 28 is also kept in the closed position, so that the short-circuit channel 27 is kept closed. At this time, the leakless valve 11 performs the same function as the load check valve. Therefore, even if the load pressure on the cylinder 1 side is higher than the discharge pressure of the combined pump hydraulic motor M that performs the pump function, the hydraulic oil flows backward. It is not.

  In the state where the switching valve S is switched to the actuator drive mode as described above, the motor / generator G is used as the electric motor by using the electric power stored in the battery (not shown), and the rotation direction as the hydraulic motor is the same. When rotating in the direction, the rotational hydraulic motor M is rotated by the rotational force and functions as a pump. That is, since the hydraulic motor M serving as a pump communicates with the tank T via the first flow path 19, the first and fourth ports 15, 18 and the connection passage 21, the hydraulic oil is sucked from the tank T. Also, the discharge oil discharged from the combined pump hydraulic motor M that performs this pump function merges with the hydraulic oil in the passage 4 via the second flow path 20 → the second port 16 → the third port 17 → the connection passage 10. Will do. Therefore, the hydraulic oil discharged from the pump / hydraulic motor M that performs the pump function functions as a power source for extending the cylinder 1.

  The second embodiment shown in FIG. 2 is such that the rotation direction of the pump combined hydraulic motor M is reversed between when it is used as a hydraulic motor and when it is used as a pump. In both the power generation mode and the actuator drive mode, the first and third ports 15 and 17 are communicated, and the second and fourth ports 16 and 18 are communicated. Further, by reversing the rotation direction of the pump combined hydraulic motor M when used as a hydraulic motor and when used as a pump, in either the power generation mode or the actuator drive mode, The first flow path 19 becomes high pressure, and the second flow path 20 becomes low pressure. Therefore, in this second embodiment, only one relief valve is sufficient. That is, only the relief valve 31 is sufficient, and the on-off valve 28 is not required as in the first embodiment. Other configurations are the same as those in the first embodiment.

  Further, the supply flow path 33 in the second embodiment is connected to both the first and second flow paths 19 and 20. Accordingly, the replenishment flow path 33 of the second embodiment is provided with two check valves 34 and 5, and the replenishment flow path 33 is connected between the check valves 34 and 35.

  In any of the above embodiments, when the actuator is a cylinder, inertial energy and potential energy act on the cylinder. However, when the actuator is, for example, a rotary hydraulic motor, only inertial energy is applied. Act. Therefore, in the case of a cylinder, both inertial energy and potential energy must be absorbed, but in the case of a hydraulic motor, it is sufficient to absorb only inertial energy.

It is a circuit diagram of a 1st embodiment. It is a circuit diagram of a 2nd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder which is an actuator S Switching valve 11 Leakless valves 15-18 First to fourth ports M Pump combined hydraulic motor G Motor combined generator 19 First flow path 20 Second flow path 27 Short-circuit flow path 28 Open / close valve 29 Check valve 33 Supply channel

Claims (6)

  A pump combined hydraulic motor and a motor combined generator connected to the pump combined hydraulic motor, a switching valve is connected to the pump combined hydraulic motor, and among the first to fourth ports provided in the switching valve, The first port is connected to one side of the pump / hydraulic motor, the second port is connected to the other side of the pump / hydraulic motor, the third port is connected to the actuator, and the fourth port is connected to the tank. When the switching valve is switched to the power generation mode, the first port and the third port communicate with each other, and the second port and the fourth port communicate with each other to return the return flow from the actuator to the hydraulic pressure combined with the pump. The return flow led to the motor and discharged from the pump combined hydraulic motor is returned to the tank via the switching valve, while the switching valve is operated in the actuator drive mode. When switching, the first port and the fourth port are communicated, the second port and the third port are communicated, and the hydraulic oil from the tank is sucked into the hydraulic pump motor that rotates using the motor / generator as a drive source And a leakless valve that allows the flow from the third port to be provided in the flow path process that connects the third port actuator to the actuator. A drive mechanism combined power generator configured to hold a load of an actuator.   2. The drive mechanism combined power generator according to claim 1, wherein when the switching valve is in a neutral position, the first and third ports are closed and the second and fourth ports are communicated with each other while maintaining a throttle opening.   Between one flow path connecting the first port of the switching valve and one side of the pump combined hydraulic motor, and the other flow path connecting the second port and the other side of the pump combined hydraulic motor. Is provided with a first relief valve for controlling the maximum pressure in the one flow path and a second relief valve for controlling the maximum pressure in the other flow path. Power generator combined with drive mechanism.   The drive mechanism / generator according to any one of claims 1 to 3, wherein a replenishment flow path is connected to one flow path connecting the first port of the switching valve and one side of the pump / hydraulic motor. .   Between one flow path connecting the first port of the switching valve and one side of the pump combined hydraulic motor, and the other flow path connecting the second port and the other side of the pump combined hydraulic motor. The short-circuit channel is provided, and the short-circuit channel is provided with a check valve that allows only a flow from the other channel to the one channel. Power generator combined with drive mechanism.   A switching control valve for controlling the actuator is provided, and the total flow rate of the flow rate Qt flowing through the switching control valve and flowing into the tank and the flow rate Qm flowing through the switching valve and flowing into the hydraulic motor is necessary for the return control of the actuator. A drive mechanism / generator according to any one of claims 1 to 7, further comprising a control mechanism for controlling the switching control valve and the opening of the switching valve while maintaining a relationship equal to the flow rate Qc. .

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