JP3787909B2 - Actuator control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention mainly relates to an actuator control method and apparatus for controlling the operation of an actuator (hydraulic motor, hydraulic cylinder) in a working machine such as a hydraulic crane or a hydraulic excavator.
[0002]
[Prior art]
For example, in a hydraulic crane, as shown in FIG. 6, the operation amount of the operation lever 1 that is manually operated by an operator is converted into an operation signal M that is an electrical signal by an operation amount detector 2 such as a potentiometer, and is input to the controller 3. The controller 3 converts the operation signal M into an actuator operation command signal and sends it to the control valve 4 of the actuator control circuit and the regulator (discharge amount controller) 6 of the variable displacement hydraulic pump 5. One that controls the operating speed or pressure of the hydraulic actuator 7 by controlling the pump discharge amount is known.
[0003]
When such an actuator control is performed, if a normal pattern is operated, it is difficult to perform a fine operation for moving the suspended load at a very low speed or a very small amount.
[0004]
Conventionally, as disclosed in Japanese Patent Publication No. 5-14801, the “normal operation mode” and the “actual operation mode” are easy to perform because the maximum value and gain of the actuator operating speed or pressure with respect to the lever operation amount are small. Set the two operation modes “operation mode”
( i ) Situations where operation is possible without particular care, such as when the load is light, the boom is short, the crane capacity is sufficient, the surroundings are open and there is no risk of hitting the load, etc. In normal operation mode,
( ii ) Situations that require attention in operation, such as when the suspended load is heavy, when the boom is long, when the crane capacity is insufficient, or when the surroundings are not open and the suspended load may collide with other objects A technology has been proposed to select the fine operation mode.
[0005]
[Problems to be solved by the invention]
However, in this known technique, switching between the normal operation mode and the fine operation mode is performed manually by the changeover switch 8 each time, so this switching operation is troublesome and burdens the operator.
[0006]
In addition, forgetting to switch or mistakes in switching are likely to occur, and an operation mode different from the operator's intention may be selected, which makes it difficult for the operator to use.
[0007]
The present invention includes an operation pattern - there is provided a control GoSo location of the actuator that can automatically switch among the plural kinds which are set the operation mode in advance depending on down.
[0008]
[Means for Solving the Problems]
According to the first aspect of the present invention, there is provided an operating means for manually operating and outputting an operation signal proportional to the operation amount, a controller for outputting an actuator operation command signal based on the operation signal, and an actuator operation command signal from the controller. Actuator control means for controlling the operation of the actuator based on the controller, wherein the controller includes an operation pattern discrimination unit and an operation mode switching unit, and the operation pattern discrimination unit includes a reference in which an operation signal is set in advance. After reaching the value, the operation pattern is set to be less than the normal operation and the normal operation depending on whether or not a preset threshold value exceeding the reference value is exceeded within a predetermined time. The operation mode switching unit is configured to be determined by the operation pattern determination unit. According to the different operation patterns, the actuator operation mode is switched between the normal operation mode and the maximum operation speed or pressure of the actuator with respect to the operation signal, and the fine operation mode with small gain. An actuator operation command signal corresponding to the mode is output .
[0009]
According to a second aspect of the present invention, there is provided an operation means for outputting an operation signal proportional to an operation amount when manually operated, a controller for outputting an actuator operation command signal based on the operation signal, and an actuator operation command signal from the controller Actuator controller for controlling the operation of the actuator based on the controller, the controller includes an operation pattern determination unit and an operation mode switching unit, and the operation pattern determination unit has an operation signal set in advance. After reaching the reference value, the operation pattern is set to a normal operation and the operation amount is smaller than this normal operation depending on whether or not a preset threshold value exceeding a reference value is exceeded within a predetermined time. And it is comprised so that it may discriminate | determine from two of the fine operation with a low operation speed, The said operation mode switching part is by the operation pattern discrimination | determination part. According to the different operation pattern, the operation mode of the actuator is switched between the normal operation mode in which the damping characteristic of the counter balance valve is low damping and the fine operation mode in which high damping is achieved. An actuator operation command signal corresponding to the mode is output .
[0010]
The invention of claim 3, in the structure according to claim 1 or 2, as a reference value, but the maximum value of the operation signal at the neutral region of the operating means is found using.
[0011]
A fourth aspect of the present invention, in the construction of claims 1 to 3, as a threshold, but the actuator operating means is operated signal value following values begin to move is found using.
[0012]
Between the normal operation mode the operating mode in accordance with the emission and fine operation operating mode - According to top Symbol configuration, the change amount of the operation signal to determine the operation pattern among the normal operation and fine operation, discriminated operation pattern eyes, Ru automatically switched in eliminates the hassle of switching operator a point-by-point operation mode in response to the work manually, the operator because it can concentrate only on the operation, the operation burden can be reduced.
[0013]
In addition, the operation pattern is determined based on the operation signal as the operator's intention, and the operation mode is switched. Is selected.
[0014]
According to the first aspect of the present invention, switching between the normal operation mode and the fine operation mode is performed by changing the maximum value and gain of the actuator operating speed or pressure with respect to the operation signal.
[0015]
By the way, in a hydraulic crane, it is common to provide a counter balance valve as a brake valve in a hydraulic control circuit in order to prevent a stall at the time of lowering a winch or a boom collapse.
[0016]
On the other hand, when performing winch lowering, boom overturning operation, etc. with a hydraulic control circuit using this counter balance valve, a hydraulic vibration phenomenon called hunting is likely to occur, so normally the pilot balance or drain line of the counter balance valve is throttled. By providing, a damping characteristic that lowers the operating speed of the counter balance valve with respect to lever operation is given, and hunting is prevented.
[0017]
According to the configuration of the second aspect, the operation mode is switched by changing the damping characteristic of the counter balance valve for preventing hunting in accordance with the operation pattern.
[0018]
That is, during normal operation by a low damping, since the operating speed is higher working pressure of the counterbalance valve is set low, the rising of the actuator speed is steeper with respect to the operation signal.
[0019]
In contrast, by the time the fine operation and high damping is set higher working pressure of the counterbalance valve, since the operating speed of the valve is lowered, the falling upstream of the actuator velocity with respect to the operation signal becomes gentle.
[0020]
Moreover, generation of surge pressure can be prevented by low damping during normal operation (normal operation mode). On the other hand, the occurrence of hunting can be prevented by high damping in the fine operation (fine operation mode).
[0021]
In this case , the operation signal is operated within a predetermined time from the reference value (maximum value in the neutral range of the operation means according to the configuration of claim 3 ) to the threshold value (according to the configuration of claim 4 ). The operation pattern is discriminated from the normal operation and the fine operation depending on whether or not the value has changed to a value equal to or less than the signal value at which the movement starts.
[0022]
That is, at the time of normal operation, largely changed operation signal in a short time, the operation signal at the time of fine operation is loose focuses on the point that varies gradually falling up to the operation pattern - to determine the emissions, the pattern - emission determination Is done accurately.
[0023]
According to the third aspect of the present invention, when the operation means is returned to the neutral position, the operation mode up to that point is automatically canceled, so there is no need to perform a special cancel operation.
[0024]
On the other hand, according to the configuration of the fourth aspect , since the operation pattern is determined and the operation mode is switched before the actuator actually starts to move, as in the case of switching to the fine operation mode after the actuator starts to move, A phenomenon such as a change in the operating speed of the actuator does not occur at the moment of switching, and the operation of the actuator is performed smoothly.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to the drawings.
[0026]
1st Embodiment (refer FIGS. 1-4)
In FIG. 1, 11 is an operation lever that is manually operated by an operator, 12 is an operation amount detector such as a potentiometer that converts the operation amount of the operation lever 11 into an electric signal M, and these constitute operation means. An operation signal M from the detector 12 is input to the controller 13.
[0027]
The controller 13 includes an operation pattern determination unit 14 and an operation mode switching unit 15.
[0028]
The operation pattern discriminating unit 14 discriminates an operation pattern from a preset normal operation and fine operation according to how the operation signal M changes.
[0029]
That is, as shown in FIG. 2, the operation amount of the operation lever 11 and the operation signal M are in a proportional relationship.
[0030]
In addition, the operation speed of the operation lever 11 is increased during normal operation, while a careful operation is required during fine operation. Therefore, the operation lever 11 is operated slowly, and thus the operation speed of the operation lever 11 is decreased.
[0031]
The operation lever 11 has a mechanical play, and the neutral point of the operation lever 11 is not a single point for improving operability, but a value having a certain width, that is, a neutral range is set. It is common to do. In order to ensure this neutral range, the operation signal M from the operation amount detector 12 may be processed in the controller 13 so as not to be transmitted to the actuator control system in the neutral range.
[0032]
The operation pattern discriminating unit 14 distinguishes between the normal operation and the fine operation by detecting the lever speed, that is, the change amount (change speed) of the operation signal M within a certain time.
[0033]
Specifically, as shown in FIGS. 2 and 3, after the operation signal M becomes a preset reference value ± M1, it is preset as a value larger than the reference value M1 within the set time Δt. It is checked whether the threshold value ± M2 or more, and the operation signal M is
( I ) As shown in FIG. 3 (a), when the threshold value M2 is exceeded, normal operation is performed.
( II ) As shown in FIG. 5B, if it is equal to or less than the threshold value M2, it is determined that the operation is fine.
[0034]
Here, the reference value M1 is set to the maximum value in the neutral range of the operation lever 11, and the threshold value M2 is set to a value smaller than a signal value at which the actuator actually starts moving by operating the lever.
[0035]
Note that the speed characteristics on the + side and − side of the operation lever 11 do not necessarily have to be the same, and the reference value M1, the threshold value M2, or the Δt value may be different between the + side and the − side. is there.
[0036]
The operation mode switching unit 15 switches the operation mode according to the operation pattern determined by the operation pattern determination unit 14.
[0037]
That is,
(I) When the normal operation pattern is determined, the normal operation mode (A in FIG. 4) is maintained with the original operation signal / actuator speed characteristic of the device.
(Ii) the fine operation pattern - when down is determined, switched to the maximum speed (or pressure) and the speed of the falling uplink (gain) becomes smaller fine operation operating mode (B in FIG. 4),
(Iii) An actuator operation command signal corresponding to both the operation modes is sent to the control valve 16 of the actuator control hydraulic circuit and the regulator 18 of the variable displacement hydraulic pump 17.
[0038]
As a result, normal operation with the characteristics shown in FIG. 4A is performed during normal operation, and fine operation with characteristics shown in FIG. 4B is performed during fine operation.
[0039]
In FIG. 4, it can be arbitrarily selected whether or not the value of the operation signal M at which the speed of the actuator starts to be the same in the normal operation mode and the fine operation mode.
[0040]
As described above, the operation pattern is discriminated from the normal operation and the fine operation according to the change of the operation signal, and the operation mode is changed between the normal operation mode and the fine operation mode according to the discriminated operation pattern. Therefore, the operator is not burdened to manually switch the operation mode one by one according to the work contents, and the operator can concentrate only on the lever operation, so the operation burden is reduced.
[0041]
In addition, since the operation pattern is discriminated based on the operation signal M as the operator's intention and the operation mode is switched, the operation is surely performed in accordance with the operator's intention in combination with forgetting to switch or no switching mistake. A mode is selected.
[0042]
Second embodiment (see FIG. 5)
Only differences from the first embodiment will be described.
[0043]
In the second embodiment, in the winch circuit of the hydraulic crane, the distinction between normal operation and fine operation is determined when the winch is lowered, and the operation mode is switched between the normal operation mode and the fine operation mode according to the determination result. is doing.
[0044]
In FIG. 5, a counter balance valve 21 as a brake valve is provided on the lower side in a hoisting / lowering circuit connecting an electromagnetic proportional control valve 16 controlled by the controller 13 and a winch motor 20 as a hydraulic actuator. Is provided. 22 is a check valve provided in parallel with the counter balance valve 21, 23 is an overload relief valve, and 24 is a main relief valve.
[0045]
Further, as a throttle for giving damping to the counter balance valve 21 and preventing hunting, a first throttle 25 is provided in the pilot line, and second and third throttles 26 and 27 are provided in the internal drain line of the valve 21. An electromagnetic valve 28 that is provided in parallel and that is switched on and off in series with the third throttle 27 is provided.
[0046]
Here, the relationship between the openings a and b of the second and third diaphragms 26 and 27 is set to a <b.
[0047]
The solenoid valve 28 is on / off controlled by a signal from the controller 13 and is turned on (opened) in the normal operation mode and turned off (cut off) in the fine operation mode.
[0048]
According to this configuration, in the fine operation mode, only the second throttle 26 having a small opening acts on the drain line (in this case, the internal drain line). Therefore, the internal damping characteristic of the counter balance valve 21 becomes high damping, and the counter balance The operating speed of the valve 21 is lowered.
[0049]
For this reason, the maximum speed and speed gain of the winch motor 20 with respect to lever operation become small during the lowering operation.
[0050]
On the other hand, in the normal operation mode, since the line of the third throttle 27 having a large opening is opened and the damping characteristic becomes low damping, the operating speed of the counter balance valve 21 is increased, and the winch for the lever operation during the lowering operation. The maximum speed and speed gain of the motor 20 are increased.
[0051]
As a result, the operation mode automatic switching operation basically similar to that of the first embodiment is performed.
[0052]
Further, in the normal operation mode, the damping is low and the counter balance valve 21 is opened quickly, so that the generation of surge pressure is prevented, and in the fine operation mode, the high damping is surely prevented from hunting.
[0053]
By the way, as a modification of the second embodiment, the operation mode may be switched by changing the damping characteristic of the pilot line of the counter balance valve 21.
[0054]
Moreover, the structure of 2nd Embodiment is applicable also at the time of the boom fall in the boom raising / lowering circuit which raises / lowers the boom of a hydraulic crane with a boom raising / lowering cylinder .
[0055]
【The invention's effect】
If according to the invention as described above, by way of change of the operation signal to determine the operation pattern among the normal operation and fine operation, discriminated operation pattern - the normal operation mode and the fine operation operating the operation mode in accordance with the emission because the Ru automatically switched between modes, it eliminates the trouble of the operator switches the point by point operation mode in accordance with the work at hand, because the operator can concentrate on the operation, the operation load is reduced.
[0056]
In addition, the operation pattern is determined based on the operation signal as the operator's intention, and the operation mode is switched. Is selected.
[0057]
According to the second aspect of the present invention, in the hydraulic control circuit provided with the counter balance valve, the operation mode is switched by changing the damping characteristic of the counter balance valve according to the operation pattern. Generation of surge pressure can be prevented in the mode, and occurrence of hunting can be reliably prevented in the fine operation mode.
[0058]
In this case , the operation signal is operated within a predetermined time from a reference value (according to the invention according to claim 3 , the maximum value in the neutral range of the operation means) to a threshold value (according to the invention according to claim 4 ). The operation pattern is discriminated from the normal operation and the fine operation depending on whether or not the value has changed to a value equal to or less than the signal value at which the movement starts.
[0059]
That is, at the time of normal operation, largely changed operation signal in a short time, the operation signal at the time of fine operation is loose focuses on the point that varies gradually falling up to the operation pattern - to determine the emissions, the pattern - emission determination Is done accurately.
[0060]
According to the invention of claim 3 , when the operation means is returned to the neutral position, the operation mode up to that point is automatically canceled, so that it is not necessary to perform a special cancel operation.
[0061]
On the other hand, according to the invention of claim 4 , since the operation pattern is discriminated before the actuator actually starts moving and the operation mode is switched, as in the case of switching to the fine operation mode after the actuator starts moving, A phenomenon such as a change in the operating speed of the actuator does not occur at the moment of switching, and the operation of the actuator is performed smoothly.
[Brief description of the drawings]
FIG. 1 is a block configuration diagram of a control device according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a relationship between a lever operation amount of an operation means and an operation signal in the apparatus.
FIGS. 3A and 3B are diagrams showing two examples of how the operation signal changes with respect to time. FIGS.
FIG. 4 is a diagram showing a relationship between an operation signal and an actuator speed.
FIG. 5 is a diagram illustrating an overall configuration of a control device according to a second embodiment of the present invention.
FIG. 6 is a block diagram of a conventional control device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Operation lever which comprises operation means 12 Same operation amount detector 13 Controller 14 Controller operation pattern discrimination | determination part 15 Operation mode switching part 16 Control valve which comprises actuator control means 17 Hydraulic pump 19 Hydraulic actuator 20 Winch motor M Operation Signal M1 Reference value M2 Threshold value 21 Counter balance valve 25, 26, 27 Throttle for giving damping to counter balance valve 28 Solenoid valve for making damping characteristic different according to operation mode

Claims (4)

An operation means that outputs an operation signal that is manually operated and is proportional to the operation amount, a controller that outputs an actuator operation command signal based on the operation signal, and an actuator operation control based on the actuator operation command signal from the controller The controller includes an operation pattern discriminating unit and an operation mode switching unit, and the operation pattern discriminating unit has a predetermined value after the operation signal reaches a preset reference value. Depending on whether or not the preset threshold value is exceeded as a value larger than the reference value within the time, the operation pattern is changed between normal operation and fine operation with a smaller operation amount and lower operation speed than this normal operation. The operation mode switching unit is configured to discriminate between two of the operation patterns determined by the operation pattern determining unit. Depending on the operation mode, the actuator operation mode is switched between the normal operation mode and the operation speed or pressure maximum value for the operation signal or the fine operation mode with a small gain, and the actuator operation according to this operation mode. An actuator control device configured to output a command signal . An operation means that outputs an operation signal that is manually operated and is proportional to an operation amount, a controller that outputs an actuator operation command signal based on the operation signal, and an actuator operation based on the actuator operation command signal from the controller. Actuator control means for controlling, the controller comprises an operation pattern discrimination unit and an operation mode switching unit, the operation pattern discrimination unit, after the operation signal reaches a preset reference value, Depending on whether or not a preset threshold value is exceeded as a value greater than the reference value within a predetermined time, the operation pattern is a normal operation and a fine operation with a smaller operation amount and lower operation speed than this normal operation. The operation mode switching unit is configured to determine the operation pattern determined by the operation pattern determination unit. The operation mode of the actuator is switched according to the operation mode between the normal operation mode in which the damping characteristics of the counter balance valve are low damping and the fine operation mode in which the damping is high. An actuator control device configured to output a command signal . As a reference value, the control device of the actuator according to claim 1 or 2, wherein the maximum value of the operation signal at the neutral region of the operating means is found using. As the threshold value, the control device of the actuator according to any one of claims 1 to 3, wherein the operating means is operated by an actuator signal values following values begin to move is found using.

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