JP2007113756A - 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 indepently both the functions. <P>SOLUTION: The equipment is equipped with the pump/hydraulic motor M 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 T 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, the motor/generator G as a drive unit, is allowed to suck a working oil from the tank and besides, a discharged oil from the pump/hydraulic motor 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 fifth 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, the fifth port is connected to the actuator via the load check valve, and the switching valve is switched to the power generation mode, the fifth port is closed, while the first port and the third port are connected. In addition to communicating, the second port and the fourth port are communicated, and the return flow from the actuator is guided from the third port to the pump combined hydraulic motor via the first port. The return flow discharged from the pump combined hydraulic motor is returned to the tank from the second port of the switching valve through the fourth port, and when the switching valve is switched to the actuator drive mode, the third port is closed. The first and fifth ports communicate with each other, the second port and the fourth port communicate with each other, and the pump / hydraulic motor that rotates using the motor / generator as a drive source includes the fourth port to the second port. The hydraulic oil sucked in from the tank via the tank is sucked in, and the discharge oil from the hydraulic pump / motor is supplied from the first port to the actuator via the fifth port.

  A second 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, A check control valve is provided in a flow path process for connecting the port to the tank and connecting the first port to one side of the hydraulic pump motor. The check control valve is connected to the one side at one switching position. And a check function that allows only the flow from the pump-cum-hydraulic motor to the actuator at the other switching position. The communication position between the first port and the third port, the communication position between the second port and the fourth port, the communication between the first port and the third port, and the second port and the fourth port. In the power generation mode, the switching valve is maintained in the operating position, the check control valve is switched to the one switching position, and in the actuator driving mode. The switching valve is maintained at the operating position, and the check control valve is switched to the other position.

  A third invention includes a pump combined hydraulic motor and a motor combined generator connected to the pump combined hydraulic motor, and a pair of switching valves is connected to the pump combined hydraulic motor. 1 port and 3rd port, the said 1st port is connected to one side of the actuator also serving as a pump, the 3rd port is connected to the actuator, and the other switching valve has 2nd port and 4th port The second port is connected to the other side of the pump combined actuator, the fourth port is connected to the tank, and one switching valve is provided between the actuator and the pump combined hydraulic motor in the power generation mode. The flow is switched between a free flow position and a restricted flow position that allows only flow from the pump-hydraulic motor to the actuator in the actuator drive mode. The other switching valve is provided with a free flow position for maintaining the second port and the fourth port in a free flow state in both the power generation mode and the actuator drive mode, and when the pump / hydraulic motor is not operated. It is characterized in that it can be switched to a throttle position where the two ports and the fourth port communicate with each other while maintaining the throttle opening.

  According to a fourth 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.

  According to a fifth aspect of the present invention, a replenishment flow path is connected to both the one flow path connected to the first port of the switching valve and the other flow path connected to the second port, and a replenishment flow path In the flow path process to the one flow path, a check valve that allows only flow from the supply flow path to the one flow path is provided, and in the flow path process to the supply flow path and the other flow path, It is characterized in that a check valve that allows only the flow from the replenishment flow path to the other flow path is provided.

  According to a sixth aspect of the present invention, there is provided the above-described one channel for connecting the first port of the switching valve and one side of the hydraulic pump motor, and the second port for connecting the other side of the hydraulic pump motor. It is characterized in that a short-circuit channel is provided between the other channel and a check valve that allows only a flow from the other channel to the one channel is provided in the short-circuit channel.

  The seventh 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 to third aspects 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.

  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, so that the rotation continues with inertia energy. The oil discharged from the pump combined hydraulic motor 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.

  Furthermore, since a load check valve is provided in the flow path process from the pump combined hydraulic motor to the actuator, when the pump combined hydraulic motor functions as a pump, the actuator operates even when the pump discharge pressure is not sufficiently secured. The oil will not flow backwards. When the pump discharge pressure of the combined pump hydraulic motor becomes a predetermined pressure or higher, the pump discharge oil is supplied to the actuator.

  According to the fourth aspect of the invention, the relief valve is provided between the one flow path and the other flow path. Therefore, when using the pump / hydraulic motor as a hydraulic motor, the relief valve is used. Moreover, those maximum pressures can be controlled by the relief valve.

  According to the fifth aspect of the present invention, since the supply flow path is connected to both flow paths, for example, even when the switching hydraulic valve motor is rotated by inertia energy in the state where the switching valve is switched to the neutral position, 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. Further, even when the pump combined hydraulic motor performs the pump function, no negative pressure is generated on the suction side.

  According to the sixth aspect of the invention, since one of the flow paths and the other flow path can be short-circuited, the hydraulic oil discharged by itself can be returned to the suction side. In addition, in conjunction with the replenishment flow path of the fifth aspect of the invention, when the switching valve is in a neutral state, 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, since there is no problem even if the pump combined hydraulic motor continues to rotate by inertial energy, a motor combined generator having a size suitable for the purpose can be freely selected. 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 seventh aspect of the present invention, the total flow rate of the flow rate Qt that flows through the switching control valve connected to the actuator and flows into the tank and the flow rate Qm that flows through the switching valve and flows into the hydraulic pump motor is controlled by the control mechanism. Since it becomes equal to the flow rate Qc required for the return control of the actuator, the operating speed of the actuator can be maintained when it is not necessary to supply the flow rate to the pump / hydraulic motor. 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.

  In addition, the cylinder 1 in this 1st 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. Also, as a matter of course, when the piston side chamber 1b is connected to the pump P, the cylinder 1 increases the load acting on it, so that inertia energy or inertia energy due to the load acts on the cylinder 1. do not do.

  The pilot control mechanism 5 controls the switching control valve 2 as described above. The pilot control mechanism 5 guides a pilot pressure to one of the pilot chambers of the switching control valve 2 by operating the operating lever 5a, and switches the switching control valve 2 with the pilot pressure as described above. ing.

  As described above, when the cylinder 1 is contracted, inertial energy and potential energy according to the load act. As described above, when the inertial energy acts on the cylinder 1 as described above, a return path is provided. 4 is connected to a switching valve S which is a 3-position 5-port valve. The switching valve S configured as described above includes first to fifth ports 6 to 10, and the first port 6 is a supply side with respect to a pump / hydraulic motor M that is a power source of the motor / generator G. One channel 11 is connected. The second port 7 is connected to the second flow path 12 on the return side with respect to the pump combined hydraulic motor M, the third port 8 is connected to the passage 4 via the connection passage 13, and the fourth port The port 9 is connected to the tank T via the connection passage 14, and the fifth port 10 is connected to the connection passage 13 via the load check valve 15. The load check valve 15 allows only the flow from the fifth port 10 to the connection passage 13.

  The switching valve S as described above is provided with pilot chambers 16 and 17 and centering springs 18 and 19 on both sides thereof. When the one pilot chamber 16 communicates with the pilot control mechanism 5 and the switching control valve 2 is switched to the left side of the drawing, in other words, when the discharge oil of the pump P is supplied to the piston side chamber 1b of the cylinder 1, A pilot pressure is applied to the pilot chamber 16. The other pilot chamber 17 is connected to a pilot pressure control valve 20, and this pilot pressure control valve 20 controls the pilot pressure according to the exciting current of the solenoid 20a. Therefore, the pilot pressure control valve 20 guides the pilot pressure corresponding to the exciting current applied to the solenoid 20a to the pilot chamber 17, and the switching valve S is switched according to the magnitude of the pilot pressure. .

  The switching valve S as described above normally maintains the neutral position shown in the figure by the action of the centering springs 18 and 19, but when the switching valve S is in the neutral position, the first, third, fifth ports 6, 8 , 10 are closed, and the second and fourth ports 7, 9 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. When the switching valve S is thus switched to the actuator drive mode, the first port 6 and the fifth port 10 communicate with each other, and the second port 7 and the fourth port 9 communicate with each other. At this time, the third port 8 is kept closed.

  When the pilot pressure is applied to the other pilot chamber 17, the switching valve S switches to the power generation mode, which is the lower position in the drawing, closes the fifth port 10, and connects the first port 6 and the third port 8. The second port 7 and the fourth port 9 are made to communicate with each other. However, the communication opening degree of each port at this time is controlled according to the exciting current of the solenoid 20a as described above. A controller (not shown) controls the exciting current of the solenoid 20a and the operation amount of the operation lever 5a of the pilot control mechanism 5 described above.

  In addition, a short-circuit channel 21 that short-circuits both the first channel 11 and the second channel 12 is provided, and the short-circuit channel 21 includes a first flow from the second channel 12. A check valve 22 that allows only the flow to the passage 11 is provided.

  Further, a relief valve 23 is provided between the first flow path 11 and the second flow path 12, and this relief valve 23 controls the maximum pressure of the first flow path 11. Further, a replenishment flow path 24 is connected to the first and second flow paths 11 and 12 so as to suck in a deficient flow rate from the tank T. In the figure, reference numerals 25 and 26 are check valves provided in the replenishment flow path 24. The check valve 25 allows only the flow from the tank T to the first flow path 11, and the check valve 26 passes from the tank T to the second flow. Only distribution to the road 12 is permitted.

  Next, the operation of the first embodiment will be described. Now, assuming that the switching control valve 2 is maintained at the neutral position shown in the drawing, the operation lever 5a of the pilot control mechanism 5 is operated to switch the switching control valve 2 to the right side of the drawing. Although supplied to the side chamber 1a, the oil discharged from the piston side chamber 1b is returned to the tank T. However, at this time, a throttle 27 is formed between the actuator port 2d of the switching control valve 2 and the tank port 2b. The opening of the throttle 27 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 20 a according to the switching amount of the switching control valve 2, that is, the opening degree of the throttle 27. Therefore, the switching amount of the switching valve S in the power generation mode is controlled according to the opening degree of the throttle 27, 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 27 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 27 is guided to the first flow path 11, 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 is stopped and a controller (not shown) functions to set the exciting current of the switching valve S to zero, The valve S is returned to the neutral position shown.

  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. Accordingly, the hydraulic oil is sucked in from the first flow path 11 side and is discharged to the second flow path 12 side. As described above, the communication between the first port 6 and the third port 8 of the switching valve S is performed. Is cut off, the pump / hydraulic motor M cannot sufficiently suck hydraulic oil from the first flow path 11.

  However, at this time, the hydraulic oil discharged from the pump combined hydraulic motor M to the second flow path 12 side is returned to the first flow path 11 side where the pressure is low via the short circuit passage 21. In addition, since the hydraulic fluid in the tank T is also supplied from the supply flow path 24, no negative pressure is generated on the suction side of the pump / hydraulic motor M, and cavitation occurs due to the negative pressure. The problem will be solved.

  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, 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, but in this embodiment, the switching valve S is repeatedly turned on and off in a short time. However, while being able to absorb the inertia energy of the generator G, a negative pressure does not generate | occur | produce on the 1st flow path 11 side, and naturally cavitation does not generate | occur | produce.

  Moreover, even if the switching valve S is suddenly switched to the neutral position shown in the figure, the second port 7 and the fourth port 9 communicate with each other while maintaining the throttle opening, so that the pump-use 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 16. Accordingly, at this time, the switching valve S is switched to the actuator drive mode which is the upper position in the drawing. When the switching valve S is switched to the actuator drive mode in this way, the first port 6 and the fifth port 10 communicate with each other, so that the first flow path 11 has the first, fifth ports 6 and 10 and the load check valve. Communicating with the connecting passage 13 through 15, and communicating with the piston side chamber 1 b of the cylinder 1 through the connecting passage 13 through the passage 4. Further, since the second port 7 and the fourth port 9 communicate with each other, the second flow path 12 communicates with the tank T.

  When the switching valve S is switched to the actuator drive mode as described above, when the motor / generator G is turned into an electric motor by using the electric power stored in the battery (not shown), the rotation is reversed from that during power generation. The pump combined hydraulic motor M is rotated by the rotational force and functions as a pump. That is, the hydraulic pump motor M that is used as a pump communicates with the tank T via the second flow path 12 and the second, fourth, and fourth ports 6 and 9, so that the hydraulic oil is drawn from the tank T. Also, the discharged oil discharged from the pump combined hydraulic motor M that performs this pump function is in the passage 4 via the first flow path 11 → the first port 6 → the fifth port 10 → the load check valve 10 → the connection passage 13. It will merge with the hydraulic oil.

  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. In addition, since the load check valve 15 is provided in the passage process between the fifth port 10 and the connection passage 13, the discharge pressure of the pump / hydraulic motor M is not sufficiently high, and the pressure difference between the passage 4 and the side is large. When this occurs, the load check valve 15 does not open. Therefore, there is no possibility that the pressure oil on the piston side chamber 1 b side of the cylinder 1 will flow back into the first flow path 11. When the discharge pressure of the pump combined hydraulic motor M becomes sufficiently high, the load check valve 15 is pushed open, and the discharge oil from the pump combined hydraulic motor M joins the passage 4 side.

  The second embodiment shown in FIG. 2 is different from the first embodiment in that the configuration of the switching valve S and the check control valve 28 are newly provided. All other configurations are the first embodiment. Is the same. Therefore, for the same constituent elements as those in the first embodiment, detailed description of the configuration and operation thereof is omitted, and the same reference numerals are used for the same constituent elements.

  The switching valve S of the second embodiment is a two-position four-port valve that can be switched between a non-operating position that is a normal position and an operating position that is a lower position in the drawing. The switching valve S includes first to fourth ports 29 to 32, the first port 29 is connected to the first flow path 11, and the second port 30 is connected to the second flow path 12. The third port 31 is connected to the piston side chamber 1b of the cylinder 1 through the connection passage 13, and the fourth port 32 is connected to the tank T through the connection passage 14.

  The switching valve S configured as described above causes the spring force of the spring 33 to act on one side, and a pilot chamber 34 is provided on the other side. A pilot pressure control valve 35 is connected to the pilot chamber 34. The pilot pressure control valve 35 controls the pilot pressure according to the excitation current of the solenoid 35a. Therefore, the pilot pressure control valve 35 guides the pilot pressure corresponding to the excitation current applied to the solenoid 35a to the pilot chamber 35, and the switching valve S is switched according to the magnitude of the pilot pressure. .

  Normally, the switching valve S configured as described above maintains the inoperative position shown in the figure by the action of the pulling 33, but when the switching valve S is in the inoperative position, the first and third ports 29 and 31 are closed. The second and fourth ports 30 and 32 communicate with each other while maintaining the throttle opening. When the switching control valve 2 is maintained at the neutral position, the switching valve S also maintains the inoperative position shown in the figure. On the other hand, when the switching control valve 2 is switched from the neutral position shown in the drawing to the left or right, a controller (not shown) detects it and excites the solenoid 35a to apply the pilot pressure to the pilot chamber 34. When the pilot pressure is applied to the pilot chamber 34, the switching valve S is switched to the operating position on the lower side of the drawing, the first port 29 and the third port 31 are communicated, and the second port 30 and the fourth port 32 are connected. To communicate. Note that a controller (not shown) controls the exciting current of the solenoid 35a and the operation amount of the operation lever 5a of the pilot control mechanism 5 described above in synchronization.

  The above-described check control valve 28 is connected to the first flow path 11, and this check control valve 28 is a two-position two-port valve. Normally, the action of the spring force of the spring 36 is applied. The one switching position which is the normal position shown in FIG. 3 is maintained, and the first flow path 11 is maintained in a free flow state. A pilot chamber 37 is provided on the side facing the spring 36. When a pilot pressure is applied to the pilot chamber 37, the check control valve 28 is switched to the other switching position by the spring force of the spring 36. . Thus, when the check control valve 28 is switched to the other switching position, a check function that allows only the flow from the pump-cum-hydraulic motor to the actuator via the first flow path 11 is exhibited.

  At the time of switching to the power generation mode, the switching control valve 2 is switched to the right position in the drawing, and the solenoid 35a of the pilot pressure control valve 35 is excited with this switching, and the pilot pressure is applied to the pilot chamber 34 of the switching valve S. Let Therefore, the switching valve S is switched from the non-operating position shown in the drawing to the operating position. When the switching valve S is switched to the operating position, the first and third ports 29 and 31 communicate with each other, and the second and fourth ports 30 and 32 communicate with each other. When the switching valve S is maintained at the operating position in this way, the check control valve 28 is maintained at the illustrated position to bring the first flow path 11 into a free flow state.

  In this way, the pressure oil corresponding to the pressure loss of the throttle 27 of the switching control valve 2 passes through the connection passage 13 → the third port 31 → the first port 29 → the check control valve 28 → the first flow path 11. Therefore, the pump combined hydraulic motor M is rotated, and the motor combined generator G is rotated to exhibit the power generation function. At this time, the return flow discharged from the pump / hydraulic motor M is returned to the tank T via the second flow path 12 → the second port 30 → the fourth port 32 → the connection passage 14.

  When the switching control valve 2 is returned to the neutral position from the above state, the switching valve S is also returned to the inoperative position. Accordingly, no pressure oil is supplied to the first flow path 11, but the pump combined hydraulic motor M and the motor combined generator G continue to rotate due to their inertial energy as in the first embodiment. At this time, the return oil discharged from the pump combined hydraulic motor M is supplied to the first flow path 11 via the short-circuit flow path 21 and the deficiency is replenished from the replenishment flow path 24. No negative pressure is generated on the one flow path 11 side. Further, since the second port 30 and the fourth port 32 of the switching valve S communicate with each other while maintaining the throttle opening, no shock is generated when the switching valve S is switched. These are exactly the same as in the first embodiment.

  Next, when switching to the actuator drive mode, the switching control valve 2 is switched to the left position in the drawing, and the solenoid 35a of the pilot pressure control valve 35 is excited in response to the switching operation of the switching control valve 2 to switch the switching valve S. A pilot pressure is applied to the pilot chamber 34. Therefore, the switching valve S is switched from the non-operating position shown in the drawing to the operating position. When the switching valve S is switched to the operating position, the first and third ports 29 and 31 communicate with each other, and the second and fourth ports 30 and 32 communicate with each other. When the switching valve S is maintained at the operating position in this way, the check control valve 28 is maintained at the illustrated position to bring the first flow path 11 into a free flow state.

  At the same time, the check control valve 28 is switched from one switching position shown in the drawing to the other switching position on the upper side of the drawing, and only the flow of the first flow path 11 to the piston side chamber 1b of the cylinder 1 is allowed. To. Then, if the pump combined hydraulic motor M is rotated by using the motor combined generator G as a drive source, the pressure oil discharged from the pump combined hydraulic motor M performing the pump function is discharged to the first flow path 11. → Load check valve 38 → First and third ports 29, 31 → Connection passage 13 → Passage 4 is supplied to the piston side chamber 1 b of the cylinder 1. The function of the load check valve 38 at this time is exactly the same as that of the load check valve 15 of the first embodiment.

  The third embodiment shown in FIG. 3 is the same as the first embodiment except that the switching valve S is separated into two switching valves S1 and S2. Therefore, also in the third embodiment, the same components as those in the first embodiment are not described in detail, and the same reference numerals are used for the same components.

  One switching valve S <b> 1 is provided with a first port 29 and a third port 31, the first port 29 communicates with the first flow path 11, and the third port 31 is connected to the connection port 13. The switching valve S1 is provided with a spring 39 on one side and a pilot chamber 40 on the opposite side of the spring 39. In addition, a pilot pressure control valve 41 is connected to the pilot chamber 40. The pilot pressure control valve 41 controls the pilot pressure according to the excitation current of the solenoid 41a. Therefore, the pilot pressure control valve 41 guides the pilot pressure corresponding to the excitation current applied to the solenoid 41a to the pilot chamber 40, and the switching valve S1 is switched according to the magnitude of the pilot pressure. .

  The one switching valve S1 configured as described above normally maintains the illustrated regulated flow position by the action of the pulling 39. At this regulated flow position, the load check valve 42 incorporated in the switched valve S1 is the first. It will be located on the flow path 11. The load check valve 42 permits only the flow from the pump / hydraulic motor M to the cylinder 1. Further, when the switching valve S1 is switched to the free flow position by the action of the pilot pressure in the pilot chamber 40, the first flow path 11 becomes free flow. When the switching control valve 2 is switched from the neutral position shown in the drawing to either the left or right, a controller (not shown) detects it, excites the solenoid 41a, and applies a pilot pressure to the pilot chamber 40. It is the same as that of an Example.

  The other switching valve S2 includes a second port 30 and a fourth port 32. The second port 30 communicates with the second flow path 12, and the fourth port 32 is connected to the connection port 14. Yes. The switching valve S2 is provided with a spring 43 on one side and a pilot chamber 44 on the opposite side of the spring 43. Moreover, a pilot pressure control valve 45 is connected to the pilot chamber 44. The pilot pressure control valve 45 controls the pilot pressure in accordance with the excitation current of the solenoid 45a. Therefore, the pilot pressure control valve 45 guides the pilot pressure corresponding to the exciting current applied to the solenoid 45a to the pilot chamber 44, and the switching valve S2 is switched according to the magnitude of the pilot pressure. .

  The other switching valve S2 configured as described above normally maintains the illustrated restriction flow position by the action of the pulling 43. At this restriction flow position, the second and fourth ports 30, 32 have a throttle opening degree. Maintain and communicate. Further, when the switching valve S <b> 2 is switched to the free flow position by the action of the pilot pressure in the pilot chamber 44, the second flow path 12 becomes free flow with respect to the connection passage 14.

  When the switching control valve 2 is switched from the neutral position shown to the left or right, a controller (not shown) detects it and excites the solenoid 41a or 44a to apply the pilot pressure to the pilot chamber 40 or 44. That is the same as the first embodiment.

  When switching to the power generation mode, the switching control valve 2 is switched to the right side of the drawing, and the solenoids 41a and 45a of the pilot pressure control valves 41 and 45 are excited with this switching, so that the pilot chambers of the switching valves S1 and S2 are excited. A pilot pressure is applied to 40 and 44. Therefore, the switching valves S1 and S2 are switched to the free flow position. When the switching valves S1 and S2 are switched in this way, the first and third ports 29 and 31 communicate with each other, and the second and fourth ports 30 and 32 also communicate with each other.

  Therefore, the pressure oil corresponding to the pressure loss of the throttle 27 of the switching control valve 2 is supplied to the pump / hydraulic motor M via the connection passage 13 → the third port 31 → the first port 29 → the first flow path 11. Therefore, the pump / hydraulic motor M rotates, and the motor / generator G is rotated to exert the power generation function. At this time, the return flow discharged from the pump / hydraulic motor M is returned to the tank T via the second flow path 12 → the second port 30 → the fourth port 32 → the connection passage 14.

  When the switching control valve 2 is returned to the neutral position from the above state, the switching valves S1 and S2 are also returned to the illustrated restriction flow position. Therefore, the flow is blocked by the load check valve 42 and no pressure oil is supplied to the first flow path 11. However, as in the first embodiment, the pump combined hydraulic motor M and the motor combined generator G have their inertia. Continue to rotate with energy. At this time, the return oil discharged from the pump combined hydraulic motor M is supplied to the first flow path 11 via the short-circuit flow path 21 and the deficiency is replenished from the replenishment flow path 24. No negative pressure is generated on the one flow path 11 side. Further, since the second port 30 and the fourth port 32 of the switching valve S communicate with each other while maintaining the throttle opening, no shock is generated when the switching valve S is switched. These are exactly the same as in the first embodiment.

  Next, when switching to the actuator drive mode, the switching control valve 2 is switched to the left position in the drawing, and at this time, only the solenoid 45a of the pilot pressure control valve 45 is excited in accordance with the switching operation of the switching control valve 2. In this way, the pilot pressure is applied to the pilot chamber 44 of the switching valve S2, and the switching valve S2 is switched to the illustrated free flow position. When the switching valve S2 is thus switched, the second and fourth ports 30 and 32 are communicated, and the first and third ports 29 and 31 are also communicated via the load check valve 42.

  At the same time, if the pump combined hydraulic motor M is rotated by using the motor combined generator G as a drive source, the pressure oil discharged from the pump combined hydraulic motor M performing the pump function is the first flow. It is supplied to the piston side chamber 1b of the cylinder 1 via the path 11 → load check valve 42 → first and third ports 29 and 31 → connection passage 13 → passage 4. The function of the load check valve 42 at this time is exactly the same as that of the load check valve 15 of the first embodiment.

  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. It is a circuit diagram of a 3rd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylinder which is an actuator S Switching valve S1 Switching valve S2 Switching valve 6-10 1st-5 port 29-32 1st-4th port M Pump combined hydraulic motor G Motor combined generator 11 1st flow path 12 2nd flow path 15 Load check valve 21 Short-circuit flow path 20 On-off valve 22 Check valve 23 Relief valve 24 Supply flow path 25, 26 Check valve

Claims (7)

  A pump combined hydraulic motor and a motor combined generator connected to the pump combined hydraulic motor, a switching valve connected to the pump combined hydraulic motor, and among the first to fifth 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 fifth port is connected to the actuator via the load check valve and the switching valve is switched to the power generation mode, the fifth port is closed, while the first port and the third port are communicated with each other. The port and the fourth port communicate with each other while maintaining the throttle opening, and the return flow from the actuator is guided from the third port to the pump combined hydraulic motor via the first port, The return flow discharged from the pump combined hydraulic motor is returned to the tank from the second port of the switching valve through the fourth port and when the switching valve is switched to the actuator drive mode, the third port is closed. On the other hand, in the hydraulic pump motor combined with the first port and the fifth port, connected with the second port and the fourth port, and rotating with a motor combined generator as a drive source, the fourth port to the second port The drive mechanism combined generator configured to suck in the hydraulic oil sucked from the tank through the pump and supply the discharge oil from the pump combined hydraulic motor to the actuator from the first port through the fifth port .   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. On the other hand, a check control valve is provided in a flow path process connecting the first port and one side of the hydraulic pump motor, and the check control valve freely flows in the flow path on the one side at one switching position. And a check function that allows only the flow from the pump-cum-hydraulic motor to the actuator at the other switching position, and the switching valve includes a first port and a third port. The communication position between the second port and the fourth port, the communication between the first port and the third port is blocked, and the second port and the fourth port are opened. It is possible to switch to the non-operating position where the degree of communication is maintained, and in the power generation mode, the switching valve is maintained in the operating position, the check control valve is switched to the one switching position, and the switching valve is operated in the actuator drive mode. A drive mechanism combined power generator configured to switch the check control valve to the other position while maintaining the position.   And a motor / generator connected to the pump / hydraulic motor, and a pair of switching valves are connected to the pump / hydraulic motor. One of the switching valves is a first port and a third port. The first port is connected to one side of the actuator serving as a pump, the third port is connected to the actuator, and the other switching valve includes a second port and a fourth port, The port is connected to the other side of the pump / actuator and the fourth port is connected to the tank. In addition, one switching valve allows the flow between the actuator and the pump / hydraulic motor to be in a free flow position in the power generation mode. And in the actuator drive mode, it is possible to switch to a regulated flow position that only allows the flow from the hydraulic motor serving as a pump to the actuator. The switching valve has a free flow position for maintaining the second port and the fourth port in a free flow state in both the power generation mode and the actuator drive mode, and the second port and the second port when the pump hydraulic motor is not operated. A drive mechanism / generator that is capable of switching between four ports to a throttle position that allows the four ports to communicate with each other while maintaining the 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. The drive mechanism / generator according to any one of claims 1 to 3, further comprising a relief valve for controlling a maximum pressure of the one flow path.   A replenishment flow path is connected to both the one flow path connected to the first port of the switching valve and the other flow path connected to the second port, and the replenishment flow path and the one flow path A check valve that allows only flow from the replenishment flow path to the one flow path is provided in the flow path process to the replenishment flow path and the other flow path. The drive mechanism combined power generation device according to any one of claims 1 to 4, further comprising a check valve that allows only flow to the flow path.   The one flow path that connects the first port of the switching valve and one side of the hydraulic pump motor, and the other flow path that connects the second port and the other side of the hydraulic pump motor A short-circuit channel is provided in between, and a check valve that allows only a flow that flows from the other channel to the one channel is provided in the short-circuit channel. Drive mechanism combined use power generator.   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 5, 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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