JP2012167518A - Control device of construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To add regeneration switching means c to a two-speed switching control valve 4 for controlling a boom cylinder BC to integrate them, thereby achieving downsizing and space-saving.SOLUTION: In a first circuit system connected to a first main pump MP1, regeneration switching means c is added to a two-speed switching control valve 4 of a boom cylinder BC which is a switching control valve with less number of switching positions than other switching control valves, to integrate the two-speed switching control valve 4 and the regeneration switching means c. And, during no operation of the boom cylinder BC, the regeneration switching means c is also maintained in an open state.

Description

  The present invention relates to a control device for a hybrid construction machine.

The present applicant has already provided such a construction machine as an application related to Japanese Patent Application No. 2010-033526.
The invention according to Japanese Patent Application No. 2010-033526 includes a pair of variable displacement first and second main pumps whose discharge amount is controlled, and the first and second circuit systems are connected to the first and second main pumps. In addition, at least one of the main pumps is connected to a power generation hydraulic motor, and an electric motor / generator is linked to the hydraulic motor.

  The first and second circuit systems are provided with a plurality of switching control valves for controlling the actuator, and when all of the switching control valves are in the neutral position, the discharge oil of the first and second main pumps is supplied to the tank. A neutral flow path is provided, and the neutral flow path is connected to the tank in a normal state in any one of the above circuit systems, and the neutral flow path is blocked by blocking communication between the neutral flow path and the tank at the switching position. A regenerative switching valve communicating with the power generation hydraulic motor is provided.

JP 2002-275945 A

Since the above-mentioned conventional device must individually provide a regenerative switching valve in any one of the circuit systems, the control device is enlarged by the amount of this regenerative switching valve, and when installing it, There was a problem of requiring a large space.
An object of the present invention is to provide an apparatus that solves the problems of downsizing and space saving of the apparatus by adding regeneration switching means to a specific control valve and integrating them.

  The first invention supplies a pair of variable displacement first and second main pumps, first and second circuit systems connected to the first and second main pumps, and discharge oil from the first and second main pumps. A power generation hydraulic motor that rotates when the motor is generated, an electric motor / generator linked to the electric power generation hydraulic motor, and a battery that stores electric power generated by the electric motor / generator. The circuit system is provided with a plurality of switching control valves for controlling the actuator, and is provided with regenerative switching means for communicating any one of the main pumps with the power generating hydraulic motor or blocking the communication.

  A switching control valve having a smaller number of switching positions than the other switching control valves is provided in any of the above circuit systems, and the regenerative switching means is added to the switching control valve having a smaller number of switching positions. Are integrated.

The switching control valve having the number of switching positions smaller than that of the other switching control valve is, for example, when the switching position of the other switching control valve is three positions, the switching position is added to the regenerative switching means. This means that it becomes a two-position switching control valve.
For example, the switching control valves for construction machinery are assembled into a block by assembling these valve bodies together with other control valves, so that the overall size of the control device can be determined by a switching control valve having a large number of switching positions. become.

Therefore, for example, even if the regenerative switching means of the present invention is added to a switching control valve having a small number of switching positions, the overall size of the control device is not affected.
The switching control valve to which the regenerative switching means is added is not limited to the type of actuator that is controlled by the switching control valve as long as the number of switching positions is smaller than that of other switching control valves.

  According to a second aspect of the present invention, either one of the first and second circuit systems is provided with a 2-speed switching control valve for performing 2-speed control of the boom cylinder as the actuator, and the regeneration switching means is provided in the 2-speed switching control valve. And switching the 2-speed switching control valve to keep the regenerative switching means in the open position. When the boom cylinder is not in operation, the main pump is switched via the regenerative switching means by switching the 2-speed switching control valve. The discharge amount is guided to the power generation hydraulic motor.

  According to the first invention, since it is not necessary to provide a regenerative switching valve separately from other switching control valves as in the prior art, the entire apparatus can be downsized and the installation space can be reduced.

  According to the second aspect of the invention, the regeneration switching means is added to the switching control valve for controlling the boom cylinder, which is optimal for large capacity control. That is, since the boom cylinder has a large control flow rate, the switching control valve for controlling the boom cylinder is also suitable for controlling a large flow rate. Therefore, if the regenerative switching means is added to the switching control valve capable of controlling a large flow rate, the flow rate supplied to the power generation hydraulic motor can be increased, and the power generation amount can be increased accordingly.

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

The illustrated embodiment is a control device for a power shovel and includes variable displacement type first and second main pumps MP1 and MP2 driven by an engine E. The first and second main pumps MP1 and MP2 are coaxially rotated. It is configured to do.
In the figure, reference numeral 1 denotes a generator provided in the engine E, which exhibits the power generation function by utilizing the surplus power of the engine E.

  The first main pump MP1 is connected to the first circuit system. The first circuit system sequentially switches from the upstream side to the switching control valve 2 for controlling the motor for left travel and the switching for controlling the turning motor. A control valve 3, a two-speed switching control valve 4 for controlling the boom cylinder BC at two speeds, a switching control valve 5 for controlling the arm cylinder, and a switching control valve 6 for controlling the auxiliary attachment are connected. 2-6 consist of spool valves.

Each of the switching control valves 2 to 6 is connected to the first main pump MP <b> 1 via the neutral flow path 7 and the parallel path 8.
A throttle 9 for pilot pressure control for generating a pilot pressure is provided in the neutral flow path 7 and downstream of the switching control valve 6. The throttle 9 generates a high pilot pressure upstream if the flow rate therethrough is large, and generates a low pilot pressure if the flow rate is small.

  Further, the neutral flow path 7 allows all or part of the oil discharged from the first main pump MP1 to pass through the throttle 9 when all of the switching control valves 2 to 6 are in the neutral position or in the vicinity of the neutral position. At this time, the flow rate passing through the throttle 9 also increases, so that a high pilot pressure is generated as described above.

  On the other hand, when the switching control valves 2 to 6 are switched in a full stroke state, the neutral flow path 7 is closed and the fluid does not flow. Therefore, in this case, there is no flow rate flowing through the throttle 9, and the pilot pressure is maintained at zero.

  However, depending on the operation amount of the switching control valves 2 to 6, a part of the pump discharge amount is led to the actuator and a part is led from the neutral flow path 7 to the tank T. A pilot pressure corresponding to the flow rate flowing through the passage 7 is generated. In other words, the throttle 9 generates a pilot pressure corresponding to the operation amount of the switching control valves 2 to 6.

  In addition, a pilot flow path 10 is connected between the switching control valve 6 and the throttle 9 in the neutral flow path 7, and the pilot flow path 10 is inclined by the first main pump MP1. Is connected to a regulator 11 for controlling

  The regulator 11 controls the tilt angle of the first main pump MP1 in inverse proportion to the pilot pressure in the pilot flow path 10, and controls the amount of displacement per one rotation. Therefore, when the switching control valves 2 to 6 are fully stroked and the flow of the neutral flow path 7 disappears and the pilot pressure becomes zero, the tilt angle of the first main pump MP1 becomes maximum, and the pushing per one rotation is performed. The amount of ablation is also maximized.

Further, the second speed switching control valve 4 for controlling the boom cylinder BC is provided with a regenerative switching means c at the right side position in the drawing in addition to the neutral position a and the boom raising position b which is the left side position in the drawing.
When the boom second speed switching control valve 4 is in the neutral position a, the neutral flow path 7 is opened and the communication between the piston side chamber 12 and the rod side chamber 13 of the boom cylinder BC is blocked.

When the boom second speed switching control valve 4 is in the boom raising position b, the communication with the neutral flow path 7 is cut off, and the discharge oil of the first main pump MP1 flowing in from the parallel passage 8 is supplied to the boom cylinder. It leads to the piston side chamber 12 of BC.
Further, when the boom second speed switching control valve 4 is switched to the right side position in the drawing, the regeneration switching means c maintains the open state with respect to the parallel passage 8 and also from the first main pump MP1 flowing in from the parallel passage 8. The pressure oil is guided to the power generation hydraulic motor M through the passage 14, and the power generation hydraulic motor M is rotated.

  The boom second speed switching control valve 4 as described above has both ends of the spool facing the pilot pressure chambers 15 and 16. One pilot pressure chamber 15 is connected to a pilot operation mechanism (not shown) controlled by an operator, and pilot pressure is guided by operating this pilot operation mechanism. Switch to b.

The other pilot pressure chamber 16 is connected to a pilot pump PP via a pilot control solenoid valve 17. This pilot control solenoid valve 17 has its solenoid connected to the controller C, and opens and closes in response to an output signal from the controller C.
When the pilot control solenoid valve 17 is in the illustrated normal position, the communication between the pilot pump PP and the pilot pressure chamber 16 is cut off, the solenoid is excited, and the pilot control solenoid valve 17 is switched to the open position. At this time, the pilot pump PP and the pilot pressure chamber 16 communicate with the pilot pump PP to keep the regeneration switching means c open.

  On the other hand, the second main pump MP2 is connected to the second circuit system. The second circuit system controls the switching control valve 18 for controlling the right traveling motor and the bucket cylinder in order from the upstream side. A switching control valve 19, a switching control valve 20 that controls the boom cylinder BC, and a second speed switching control valve 21 that controls the arm cylinder at the second speed are connected. These switching control valves 18 to 21 are spool valves.

The switching control valves 18 to 21 communicate with each other through a neutral flow path 22 communicating with the second main pump MP2, and the switching control valves 19 and 20 are connected to the second main pump MP2 through a parallel passage 23. is doing.
A pilot pressure control throttle 24 is provided downstream of the switching control valve 21 in the neutral flow path 22. The throttle 24 functions in the same manner as the throttle 9 of the first circuit system. Is.

In addition, a pilot flow path 25 is connected between the switching control valve 21 and the throttle 24 in the neutral flow path 22. The pilot flow path 25 is inclined by the second main pump MP2. It is connected to a regulator 27 that controls the turning angle.
The regulator 27 controls the tilt angle of the second main pump MP2 in inverse proportion to the pilot pressure led to it, and controls the amount of push-off per one rotation.

  Further, the switching control valve 20 for controlling the boom cylinder BC communicates with the neutral flow path 22 when it is in the neutral position shown in the figure, and guides the pressure oil supplied to the neutral flow path 22 to the tank T. When the pilot pressure is guided to one pilot pressure chamber 20a of the switching control valve 20, the switching control valve 20 switches to the boom raising position on the left side of the drawing, and the pilot pressure is guided to the other pilot pressure chamber 20b. When it is, it switches to the boom lowering position, which is the right side of the drawing.

  The pilot pressure chamber 20a on the one side communicates with one pilot pressure chamber 15 of the second speed switching control valve 4 described above. Therefore, when the pilot operating mechanism described above is operated to raise the boom cylinder BC, the pilot pressure is simultaneously introduced into the pilot pressure chambers 15 and 20a. In other words, in the ascending mode of the boom cylinder BC, the switching control valves 4 and 20 are switched, and the discharge oil of the first and second main pumps MP1 and MP2 merges in the passage 28 and enters the piston side chamber 12 of the boom cylinder BC. Supplied.

  A distribution control valve 29 is provided in the passage 28 as described above, and this distribution control valve 29 can be switched between a normal mode ascending mode position a and a switching position as distribution mode position b. Yes. That is, the distribution control valve 29 normally maintains the rising mode position a by the action of the spring 30 provided on one side thereof, and when the pilot pressure is applied to the pilot pressure chamber 31 provided on the other side, the distribution mode position b is obtained. It is configured to switch to.

  At the ascending mode position a, the passage 28 is kept fully open, while at the distribution mode position b, if the opening relative to the passage 14 or 28 is increased and the opening relative to one passage is increased, the passage relative to the other passage is maintained. Control to reduce the opening.

The distribution control valve 29 configured as described above has its pilot pressure chamber 31 connected to the pilot control solenoid valve 32. The pilot control solenoid valve 32 is switched in accordance with a signal output from the controller C. Is controlled. In other words, the opening degree of the pilot control electromagnetic valve 32 is controlled according to the signal from the controller C, and the pilot pressure guided to the pilot pressure chamber 31 of the distribution control valve 29 is controlled according to the controlled opening degree. Is done.
Therefore, the opening degree of the distribution control valve 29 with respect to the passages 14 and 28 is controlled according to the output signal of the controller C.

Further, the controller C includes determination means (not shown) that determines the switching direction and switching amount of the switching control valve 20 connected to the boom cylinder BC via the pilot operation mechanism. Then, the controller C determines the switching direction and switching amount of the switching control valve 20 by the determination means, and controls a signal to the pilot control electromagnetic valve 32 according to the switching direction and switching amount.
The determination means of the controller C also has a function of determining whether all the switching control valves 2 to 6 and 18 to 21 are in the neutral position or the switching position.

Further, the power generation hydraulic motor M connected to the passage 14 is linked to the motor / generator 33, and when the power generation hydraulic motor M rotates, the motor / generator 33 rotates to generate electric power, and the inverter 34 generates power. The battery 35 is charged with electric power. The controller C has a function of monitoring the charge amount of the battery 35.
The tilt angle controller 36 is controlled by an output signal from the controller C. The tilt angle controller 36 controls the tilt angle of the power generation hydraulic motor M.

  In the figure, reference numeral 37 denotes a battery charger for charging the battery 35 with the electric power generated by the generator 1. In this embodiment, the battery charger 37 is connected to another system such as a household power source. A power source 38 is also connected.

  Furthermore, an assist pump AP that rotates in cooperation with the power generation hydraulic motor M is provided. The assist pump AP is provided with an inclination controller 39 that is controlled by the controller C.

  The assist pump AP thus configured is connected to the junctions 42 and 43 between the first and second main pumps MP1 and MP2 and the first and second circuit systems via the first and second junction control valves 40 and 41. However, the first and second merging control valves 40 and 41 are each provided with a pilot pressure chamber, and a spring is provided on the side facing the pilot pressure chamber. The first and second merging control valves 40 and 41 are configured to maintain the open position in the illustrated normal state and switch to the closed position against the spring when the pilot pressure is applied to the pilot pressure chamber.

  Furthermore, the pilot pressure chambers of the first and second merging control valves 40 and 41 are connected to the pilot pump PP via first and second electromagnetic control valves 44 and 45. The valves 44 and 45 are controlled by the output signal of the controller C. In the illustrated normal state, the valves 44 and 45 are kept in the closed position, and the pilot pump PP communicates with the pilot pressure chambers of the first and second merging control valves 40 and 41. Shut off.

Further, when the first and second electromagnetic control valves 44 and 45 are switched to the open position by the output signal of the controller C, the discharge pressure of the pilot pump PP is guided to the pilot pressure chambers of the first and second merging control valves 40 and 41. . Therefore, at this time, the first and second merging control valves 40 and 41 are switched to the closed position, and the flow between the assist pump AP and the merging points 42 and 43 is blocked.
In the figure, reference numerals 46 and 47 denote check valves, which allow only the flow from the assist pump AP to the junctions 42 and 43.

Next, the operation of this embodiment will be described.
When all the switching control valves 2 to 6 and 18 to 21 of the first and second circuit systems are held in the neutral position, the pressure on the upstream side of the throttles 9 and 24 becomes the highest, so that the regulators 11 and 27 In operation, the push-out amount per rotation of the first and second main pumps MP1, MP2 is kept to a minimum.

From this state, for example, when the pilot operating mechanism is operated to introduce the pilot pressure into the pilot pressure chamber 20a of the switching control valve 20, and the switching control valve 20 is switched to the boom raising position, which is the left position in the drawing, Since this pilot pressure also acts on one pilot pressure chamber 15 of the 2-speed switching control valve 4, the 2-speed switching control valve 4 is also switched to the boom raising position b.
Note that the determination means of the controller C determines that the boom cylinder BC is in a mode for raising the boom cylinder BC according to the operation direction of the pilot operation mechanism, and brings the pilot control solenoid valve 17 and the pilot control solenoid valve 32 to the normal positions shown in the figure. Hold.

If the switching control valve 20 and the second speed switching control valve 4 are switched to the boom raising position as described above, the pressure on the upstream side of the throttles 9 and 24 is controlled according to the switching amount, and the control is performed. The discharge amount of the first and second main pumps MP1, MP2 increases according to the pressure.
At this time, as described above, the pilot control solenoid valve 32 maintains the closed position, which is the normal position, so that the distribution control valve 29 maintains the ascending mode position a.

Therefore, the oil discharged from the first main pump MP1 flows into the passage 28 via the parallel passage 8 and the second speed switching control valve 4. Further, the oil discharged from the second main pump MP2 flows into the passage 28 via the parallel passage 23 and the switching control valve 20. That is, the oil discharged from the first and second main pumps MP1 and MP2 joins in the passage 28.
Since the discharge oil of the first and second main pumps MP1 and MP2 joined in the passage 28 in this way is supplied to the piston side chamber 12 of the boom cylinder BC via the distribution control valve 29 in the ascending mode position a. The boom cylinder BC extends.

  On the other hand, when the pilot operating mechanism is operated to introduce the pilot pressure into the other pilot pressure chamber 20b of the switching control valve 20, the switching control valve 20 is switched to the boom lowering position which is the right side position in the drawing. At this time, the determination means of the controller C determines that the boom cylinder BC is in the lowering mode according to the operation direction of the pilot operation mechanism, and the controller C determines whether the operator operates the operator according to the operation amount of the pilot operation mechanism. Calculate the desired descent speed.

  The controller C switches the pilot control solenoid valve 32 based on the determination result, and the opening degree of the pilot control solenoid valve 32 is controlled according to the switching amount of the switching control valve 20. Therefore, the pilot pressure guided to the pilot pressure chamber 31 of the distribution control valve 29 is controlled according to the switching amount of the switching control valve 20, that is, the lowering speed of the boom cylinder BC desired by the operator.

That is, the distribution control valve 29 supplies the total return flow rate of the boom cylinder BC to Qt, the flow rate returned to the tank T through the throttle of the distribution control valve 29, Qa, and is supplied to the passage 14 through the check valve. When the flow rate is Qb, control is performed so as to maintain the relationship of Qt = Qa + Qb.
As described above, the distribution control valve 29 controls the total flow rate of the flow rate Qa returning to the tank T and the flow rate Qb guided to the passage 14 to be always equal to the total return flow rate Qt. The operator's feeling of operation does not go wrong even when

  On the other hand, when the pilot control solenoid valve 17 is switched by a signal from the controller C when the switching control valve for controlling the working actuator is in the neutral position or when the boom cylinder BC is not working, the two-speed switching control valve The pilot pressure is led to the pilot pressure chamber 16 of No. 4, and when the pilot pressure is led to the pilot pressure chamber 16 in this way, the second speed switching control valve 4 opens the regeneration switching means c. When the regenerative switching means c is opened, the pressure oil from the parallel passage 8 is guided to the passage 14 via the regenerative switching means c and from there to the power generation hydraulic motor M.

  In any case, pressure oil is supplied from the passage 14 to rotate the power generation hydraulic motor M. If the power generation hydraulic motor M rotates, the electric motor / generator 33 generates power, and the amount of power generated is an inverter. The battery 35 is charged via 34.

Since the power generation hydraulic motor M is also linked to the assist pump AP as described above, the power source of the battery 35 can be used as a power source for the assist pump AP.
At this time, the controller C controls the push-out amount per rotation by the regulator 39 of the assist pump AP.

  At this time, when the operator needs an assisting force for both the first and second circuit systems, the controller C keeps the first and second electromagnetic control valves 44 and 45 in the closed position in the normal state. When an assist force is required for this circuit system, the controller C switches either one of the first and second electromagnetic control valves 44 and 45 to the open position, Switch one to the closed position. Further, when the assist force of the assist pump AP is not required in any of the first and second circuit systems, the controller C excites both solenoids of the first and second electromagnetic control valves 44 and 45 to The 1 and 2 merge control valves 40 and 41 are switched to the closed position.

  In the above embodiment, the regeneration switching means c is added to the second speed switching control valve 4 of the boom cylinder BC. However, any switching control valve can be used as long as the switching control valve has a smaller number of switching positions than the other switching control valves. A regeneration switching means may be added to the control valve. For example, the regeneration switching means c may be added to the attachment switching control valve.

  Ideal for hybrid type excavators.

MP1 1st main pump MP2 2nd main pumps 2, 3, 5, 6 Switching control valve 4 2nd speed switching control valve c Regeneration switching means BC Boom cylinder 7 Neutral flow path M Power generation hydraulic motors 15, 16 Pilot pressure chamber 17, 32 Pilot control solenoid valve 18 to 21 Switching control valve 33 Electric motor / generator 35 Battery

Claims (2)

  A pair of variable displacement type first and second main pumps, first and second circuit systems connected to the first and second main pumps, and the oil discharged from the first and second main pumps are rotated. A power generation hydraulic motor, an electric motor / generator linked to the electric power generation hydraulic motor, and a battery for storing electric power generated by the electric motor / generator, the first and second circuit systems controlling the actuator In a construction machine control device provided with a regenerative switching means for providing a plurality of switching control valves and connecting one of the main pumps to the power generating hydraulic motor or blocking the communication. In the circuit system, a switching control valve having a smaller number of switching positions than other switching control valves is provided, and the regenerative switching means is added to the switching control valve having a smaller number of switching positions. Construction machine control system that integrates them Te.   One of the first and second circuit systems is provided with a two-speed switching control valve for controlling the second speed of the boom cylinder as the actuator, and the regeneration switching means is added to the two-speed switching control valve. The regenerative switching means is maintained in the open position by switching the 2-speed switching control valve, and when the boom cylinder is not in operation, the 2-speed switching control valve is switched and the discharge amount of the main pump is generated for power generation via the regenerative switching means. The construction machine control device according to claim 1, wherein the construction machine control device is guided to a hydraulic motor.

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