JP4282119B2 - Hydraulic drive control device for work equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hydraulic drive control device for a working machine.
[0002]
[Prior art]
Conventionally, there are an aerial work vehicle, a mobile crane, a cave excavator, and the like as this type of work machine, and the following will be described by taking the aerial work vehicle shown in FIG. In FIG. 3, the aerial work vehicle has a turntable 2 that can turn freely on a vehicle 1, and a turning drive device that is turned by a turning motor is arranged between the turntable 2 and the vehicle 1. A telescopic boom 3 is disposed on the swivel base 2 so that it can be raised and lowered. The telescopic boom 3 is sequentially fitted with multi-stage booms, and a telescopic drive device that is telescopically driven by an telescopic cylinder or the like is disposed between the booms. A hoisting cylinder 4 is arranged at an appropriate position between the telescopic boom 3 and the swivel base 2 so that the telescopic boom 3 can be driven to hoist. The telescopic boom 3 is provided with a work platform 5 for boarding an operator, and each operating means 6a, 7a, 8a for turning the swivel base 2 and expanding / contracting the undulating boom 3 on the work base 5 (invoice). This corresponds to the operation means described in Item 1.), and the aerial work vehicle can be driven and controlled by operating the operation levers 6, 7, 8 disposed on the operation means 6a, 7a, 8a. It is.
[0003]
The aerial work vehicle configured in this manner performs turning of the turntable 2, expansion / contraction of the telescopic boom 3, and undulation by the operator who has boarded the worktable 5 operating the operation levers 6, 7, 8. As a result, the worker who has boarded the work table 5 is positioned at an arbitrary position and works at a high place. And each hydraulic actuator of the turning motor, the extension cylinder, and the raising / lowering cylinder 4 for turning, extending / contracting and raising / lowering is driven by a hydraulic source obtained by driving a hydraulic pump using a traveling engine of an aerial work vehicle. I have to. For example, the case where the hoisting cylinder 4 shown in FIG. 4 is driven will be described below as an example. Similarly, the case where the telescopic cylinder and the turning motor are driven is similarly configured.
[0004]
In FIG. 4, the valve controller 9 outputs a control signal based on the operation signal from the undulation operating means 8a. In response to the control signal from the valve controller 9, the control valve 10 drives and controls the undulation cylinder 4. The amount of oil discharged from the hydraulic pump 12 is determined by the rotation of the traveling engine 11. The rotation of the engine 11 is maintained at a high speed when the undulation operation lever 8 is operated, and is a small rotation (when it is not operated). (Idling state). That is, the rotation of the hoisting operation lever 8 and the engine 11 is output by the accelerator controller 13 to the accelerator 11a of the engine 11 based on the information of the operation signal of the hoisting operation means 8a. .
[0005]
By the way, when the hoisting operation lever 8 is suddenly returned from the operating position to the non-operating position, the hoisting cylinder 4 suddenly stops and the operator who has boarded the work table 5 receives a shock due to the sudden stop and becomes uncomfortable. It was. Therefore, the valve controller 9 is provided with a slow stop function 14 so that the control valve 10 is not suddenly closed even if the hoisting operation lever 8 is suddenly stopped, so that the control signal output from the valve controller 9 is delayed and attenuated. is there. This control signal differs in the delay time of the control signal output from the valve controller 9 depending on the operation amount of the hoisting operation lever 8 (driving speed of the hoisting cylinder 4) before the non-operating position. That is, as shown in FIG. 5 for illustrating the relationship when the drive of the hoisting cylinder 4 is stopped, when the operating amount of the hoisting operation lever 8 is P1, if the sudden stop operation is performed, the control valve 10 is attenuated in time t1 until the control valve 10 is closed. A control signal is output from the valve controller 9. On the other hand, if the operation amount of the hoisting operation lever 8 is the maximum operation P2 (P1 <P2), if a sudden stop operation is performed, a control signal that attenuates in the time t2 (t1 <t2) until the control valve 10 is closed is a valve controller 9. Is output from. (Figures 5a and 5b)
[0006]
Since the valve controller 9 is provided with the slow stop function 14 as described above, when the hoisting operation lever 8 is suddenly returned from the operation position to the non-operation position, the rotation of the engine 11 is immediately changed from high to low. Therefore, although the undulating cylinder 4 is operated by the slow stop function 14, the engine 11 becomes low in rotation, the amount of oil discharged from the hydraulic pump 12 becomes insufficient, the engine 11 is heavily loaded, and the engine 11 is stalled. It becomes a state. Therefore, when the accelerator controller 13 receives the operation signal from the hoisting operation means 8a and suddenly returns the hoisting operation lever 8 from the operating position to the non-operating position as shown in FIG. To the time t3 until the control valve 10 is closed (time t3 from when the hoisting operation lever 8 is suddenly returned to the non-operation position until the control valve 10 is closed) over the time t3. A signal is output to the accelerator 11a of the engine 11 so as to maintain the rotation.
[0007]
[Problems to be solved by the invention]
However, when the operating amount of the hoisting operation lever 8 is suddenly returned to non-operation when it is operated to P1, it is suddenly not operated when the operating amount of the hoisting operation lever 8 is operated to the maximum P2. Even when the engine 11 is returned to the initial position, the engine 11 maintains the high rotation for the time t3 after the hoisting lever 8 is not operated. Therefore, when the operation amount of the hoisting operation lever 8 is operated to P1, when the operation is suddenly returned to the non-operation, the hoisting drive of the hoisting cylinder 4 is already stopped, but the engine 11 is maintained at a high speed. The engine 11 continues to rotate at a high speed for a while even though the operation is finished. On the other hand, when the operation amount of the hoisting operation lever 8 is operated to P2, when it is suddenly returned to non-operation, the time interval after the hoisting drive of the hoisting cylinder 4 is stopped is not so much, and the engine 11 is maintained at a low speed. . That is, when the operation amount of the hoisting operation lever 8 is operated to P1 and when the operation amount of the hoisting operation lever 8 is operated to P2, the rotation of the engine 11 is stopped after the hoisting motion of the hoisting cylinder 4 is stopped. The time interval until low rotation is different, and the operational feeling varies depending on the amount of operation of the operating lever, and the operability is uncomfortable. In addition, since the engine 11 rotates at a high speed for a while, when the hoisting lever 8 is set to the non-operating state from the state in which the operating amount of the hoisting lever 8 is operated to P1, the rotation sound of the hydraulic pump is rotated. May feel noisy. Furthermore, it is uneconomical to rotate the engine 11 wastefully from the viewpoint of energy consumption. An object of the present invention is to provide a hydraulic drive control device for a working machine that solves such problems.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a hydraulic control device for a work machine according to the present invention includes an operation means, a valve controller that outputs a control signal based on an operation signal from the operation means, and a control signal from the valve controller. A control valve for driving and controlling the hydraulic actuator, and a hydraulic pump that is driven by the driving device and supplies the discharged oil to the hydraulic actuator via the control valve. When operating the operating means, the amount of discharged oil is increased. a hydraulic drive control device for a working machine for controlling the valve controller gradually attenuates the control signal when the operating means to the non-operation, the delay time of the control signal for the damping to the drive speed of the hydraulic actuator has a slow stop function that varied depending, said hydraulic drive control device before receiving the control signal from the valve controller Anda discharge oil amount control means for controlling the discharge oil amount of the hydraulic pump, the discharge oil amount controlling means receives a control signal output from the valve controller during non-operation of the operating means, wherein the control signal is attenuated From the time point when the valve controller stops outputting to the discharge oil amount control means, the discharge oil amount of the hydraulic pump is adjusted so that the discharge oil amount of the hydraulic pump is maintained at a large oil amount and then reduced to a small oil amount until a predetermined time. Control is based on a control signal output from the valve controller .
[0009]
According to a second aspect of the present invention, there is provided a hydraulic control device for a work machine according to the first aspect of the present invention, wherein the hydraulic control device for the work machine includes a work state detection unit that detects a work state of the work machine, and the slow stop function is The control signal is gradually attenuated in response to the signal from the work condition detecting means in accordance with the work condition of the work implement.
[0010]
According to a third aspect of the present invention, there is provided a hydraulic control apparatus for a working machine according to the first aspect, wherein the drive device of the hydraulic control apparatus for the working machine according to the first aspect is configured by an engine or an electric motor, and the discharge oil amount control means is an operating means. The engine or electric motor is set to high rotation during the operation, and the engine or electric motor is maintained at high rotation for a predetermined time from the point when the control signal is not output from the valve controller when the operation means is not operated. It is characterized by that.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a hydraulic control device for a working machine according to the present invention will be described with reference to FIGS. 1 and 2. In the description, reference numerals 1 to 13, reference numeral 11a, reference numerals 6a, 7a and 8a, reference signs P1 and P2, and reference signs V1 and V2 described in the prior art are the same in the following description, and the same reference numerals are used. The detailed explanation is omitted.
[0012]
In FIG. 1, reference numeral 15 denotes an accelerator controller (corresponding to the discharge oil amount control means described in claim 1), which receives an operation signal from the undulation operation means 8 a and a control signal from the valve controller 9. When the hoisting operation lever 8 is operated, a signal is output to the accelerator 11a of the engine 11 so that the amount of oil discharged from the hydraulic pump 12 is large, and the engine 11 is rotated at a high speed. When the hoisting operation lever 8 is not operated, the rotation of the engine 11 is maintained at a high speed until a predetermined time (t4) from when the control signal is not output from the valve controller 9, and then the rotation of the engine 11 is reduced to a low speed. A signal is output to the accelerator 11a so that the amount of oil is small.
[0013]
The hydraulic control device for a working machine according to the present invention that constitutes the accelerator controller 15 as described above controls the rotation of the engine 11 as shown in FIG. That is, in FIG. 2, when the operation amount of the hoisting operation lever 8 is operated to P1, the valve controller 9 outputs a control signal only for t1 time when it is suddenly returned to non-operation. Therefore, as shown in FIG. 2B, the control valve 10 closes the valve opening after time t1, and the drive of the hoisting cylinder 4 stops. As described above, a signal is output to the accelerator 11a by the accelerator controller 15 as described above, and as shown in FIG. 2 (c), after the control valve 10 is closed, the high rotation is maintained until t4 hours, and thereafter Reduce the engine speed. (Indicated by the solid line in (c) of FIG. 2)
[0014]
On the other hand, when the operation amount of the hoisting operation lever 8 is operated to the maximum P2, when it is suddenly returned to non-operation, the valve controller 9 outputs a control signal for t2 time. Therefore, as shown in FIG. 2B, the control valve 10 closes the valve opening after t2 time, and the drive of the hoisting cylinder 4 stops. As described above, a signal is output to the accelerator 11a by the accelerator controller 15 as described above, and as shown in FIG. 2 (c), after the control valve 10 is closed, the high rotation is maintained until t4 hours, and thereafter Reduce the engine speed. (Indicated by the alternate long and short dash line in FIG. 2C)
[0015]
As described above, when the operation amount of the hoisting operation lever 8 is operated to P1 and the operation is suddenly returned, and when the operation amount of the hoisting operation lever 8 is operated to P2 (maximum operation), the operation is suddenly returned. Although the time from when the operation is returned by the slow stop function 14 to when the driving of the hoisting cylinder 4 is different is different, the time from when the driving of the hoisting cylinder 4 stops until the engine 11 changes from high to low. Becomes the same at t4.
[0016]
That is, when the operation amount of the hoisting operation lever 8 is operated to P1 and when the operation amount of the hoisting operation lever 8 is operated to P2, the rotation of the engine 11 is stopped after the hoisting motion of the hoisting cylinder 4 is stopped. The time interval until low rotation is different, and the difference in operation feeling occurs depending on the operation amount of the operation lever, so that it is possible to eliminate the feeling that the operability is uncomfortable.
[0017]
Further, even when the operation amount of the hoisting operation lever 8 is set to P1, or from the state where the operation amount of the hoisting operation lever 8 is operated to P2 (maximum), the hoisting cylinder 4 is set after the hoisting operation lever 8 is brought into the non-operation state. Since the engine rotation is set to a low rotation after the same t4 hours after the driving of the engine is stopped, the engine 11 is kept high for a while to immediately perform the work at a high place after the hoisting operation lever 8 is not operated. Without rotating, it is possible to eliminate the feeling of noisy rotating sound. Furthermore, from the viewpoint of energy saving, the engine 11 can be efficiently rotated, which is economical.
[0018]
In the above description of the embodiment, the case where the hoisting cylinder 4 is controlled as the hydraulic actuator of the working machine has been described. However, it is needless to say that the embodiment can be similarly applied to the hydraulic actuator of the telescopic cylinder and the swing motor.
[0019]
In the description of the above embodiment, the slow stop function 14 receives the operation signal from the hoisting operation means 8a and gradually attenuates the control signal output from the valve controller 9 according to the driving speed of the hoisting cylinder 4. As described above, the undulation speed detector that directly detects the undulation speed of the undulation cylinder 4 is arranged, and a signal from this detector is input to the valve controller 9 to gradually attenuate the control signal output from the valve controller 9. You may do it.
[0020]
Further, as shown in FIG. 1, a work state detection means 16 for detecting the work state of the work machine is arranged, and a signal from the work state detection means 16 is input to the valve controller 9 in accordance with the work state of the work machine. However, the control signal output from the valve controller 9 may be gradually attenuated. For example, the working machine is equipped with a boom length detector for the telescopic boom 3 as the work state detecting means 16, and the control signal is output from the valve controller 9 so that the attenuation time is increased as the boom length of the telescopic boom 3 increases. You can do it. Further, the working machine is provided with detectors such as a boom length detector and a undulation angle detector of the telescopic boom 3 as the working state detecting means 16, and the valve controller 9 receives a signal from these detectors to obtain a working radius. The control signal may be output so that the decay time becomes longer as the working radius increases.
[0021]
Furthermore, in the description of the above embodiment, the engine 11 is used as the drive device of the hydraulic pump 12 and the accelerator controller 15 that outputs a signal to the accelerator 11a of the engine 11 is described as the discharge oil amount control means. A device that uses an electric motor as the device and controls the rotation of the electric motor may be used as the discharge oil amount control means. Further, the hydraulic pump 12 may be a variable displacement hydraulic pump, and the discharge oil amount control means may be configured by control means for changing the discharge capacity of the variable displacement hydraulic pump.
[0022]
Next, in the description of the above-described embodiment, as the operation means, the raising / lowering operation means 8a, the expansion / contraction operation means 7a, and the turning operation means 6a of the work machine have been described, but a plurality of hydraulic actuators are simultaneously driven and controlled by one operation lever. It is also possible to apply the control lever, for example, horizontal operation means used when the work table 5 is moved horizontally and vertically, and discharge oil amount control means for controlling the amount of oil discharged from the hydraulic pump when the vertical operation means is operated. Is possible.
[0023]
【The invention's effect】
The hydraulic drive control device for a working machine according to the present invention configured and operated as described above is configured so that the time interval until the amount of oil discharged from the hydraulic pump becomes small after the hydraulic actuator is stopped depends on the operation amount of the operation means. In contrast, it is possible to eliminate the fact that the difference in operation feeling is caused by the operation amount of the operation lever, and that the operability is uncomfortable.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating a hydraulic drive control device for a working machine according to the present invention.
FIG. 2 is a time chart illustrating a hydraulic drive control device for a working machine according to the present invention.
FIG. 3 is an explanatory diagram for explaining an aerial work vehicle.
FIG. 4 is an explanatory diagram illustrating a conventional hydraulic drive control device for a working machine.
FIG. 5 is a time chart illustrating a conventional hydraulic drive control device for a working machine.
[Explanation of symbols]
4 Undulating cylinder (hydraulic actuator)
6a Turning operation means (operation means)
7a Telescopic operation means (operation means)
8a Relief operation means (operation means)
9 Valve controller 10 Control valve 12 Hydraulic pump 14 Slow stop function 15 Discharged oil amount control means 16 Work condition detection means

Claims (3)

An operation means, a valve controller that outputs a control signal based on an operation signal from the operation means, a control valve that receives and controls the hydraulic actuator in response to the control signal from the valve controller, and a discharge device that is driven by the drive device A hydraulic pump that supplies a hydraulic pump to the hydraulic actuator via a control valve, and controls a discharge oil amount to a large oil amount when the operation means is operated, wherein the valve controller is an operation means to non-engineered gradually attenuate the control signal when the delay time of the control signal for the attenuating have slow stop function that varied depending on the driving speed of the hydraulic actuator, the hydraulic drive control device wherein A discharge oil amount control means for receiving a control signal output from the valve controller and controlling a discharge oil amount of the hydraulic pump; For example, the discharge oil amount control means at the time of non-operation of the operating means receives a control signal output from the valve controller, the control signal attenuates the predetermined time from the time that is no longer output to the discharge oil amount control means from the valve controller Until the amount of oil discharged from the hydraulic pump is maintained at a large oil amount, and thereafter the amount of oil discharged from the hydraulic pump is controlled based on a control signal output from the valve controller. Hydraulic drive control device for working machines.  Work state detecting means for detecting the work state of the work machine is arranged, and the slow stop function receives the signal from the work state detection means so as to gradually attenuate the control signal according to the work state of the work machine. The hydraulic drive control device for a working machine according to claim 1, wherein  The drive device is composed of an engine or an electric motor, and the discharge oil amount control means makes the engine or the electric motor rotate at a high speed when the operation means is operated, and no control signal is output from the valve controller when the operation means is not operated. 2. The hydraulic drive control device for a working machine according to claim 1, wherein the engine or the electric motor is maintained at a high rotation speed for a predetermined time from the time point, and is then rotated at a low rotation speed.

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