JP2628418B2 - Hydraulic actuator control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic actuator control device suitable for use in a construction machine such as a hydraulic excavator, and more particularly to a hydraulic actuator control device capable of appropriately changing a dynamic response characteristic.

[0002]

2. Description of the Related Art FIGS. 8 to 12 show a conventional hydraulic actuator control device.

In FIG. 1, reference numeral 1 denotes a variable displacement hydraulic pump which constitutes a hydraulic power source together with a tank 2. Reference numeral 3 denotes a cylinder as an actuator connected to the hydraulic pump 1 and the tank 2 via a pair of main pipelines 4A and 4B. The cylinder device 3 includes a tube 3A, a piston 3B defining the inside of the tube 3A as oil chambers A and B, and a rod 3C having one end fixed to the piston 3B and protruding outside the tube 3A. And constitutes, for example, a boom cylinder, an arm cylinder or a bucket cylinder (not shown) of a hydraulic shovel.

Reference numeral 5 denotes an electromagnetic proportional control valve provided in the middle of the main pipelines 4A and 4B. The control valve 5 outputs a control signal to the left and right electromagnetic proportional solenoids 5A and 5B. Left and right switching positions (b) from the neutral position (b),
The direction of the pressure oil supplied to and discharged from the cylinder device 3 is switched at the switching positions (b) and (c). The control valve 5 has a stroke amount for switching from the neutral position (a) to the switching positions (b) and (c) according to the voltage value (current value) of the control signal output to the solenoids 5A and 5B. It is set variably, and is configured to control the flow rate of pressure oil supplied and discharged from the hydraulic pump 1 to the cylinder device 3 according to the stroke amount.

Reference numeral 6 denotes an operating lever device as operating means operated by an operator to operate and stop the cylinder device 3. The operating lever device 6 has a built-in potentiometer (not shown) and the like, and has an operating lever 6A. Is tilted in the direction indicated by the arrow C, as shown in FIG.
Is output as a voltage value. Reference numeral 7 denotes a controller that outputs a control signal based on a command signal Vi from the operation lever device 6. The controller 7 is connected to a power supply 8, the input side of which is connected to the operation lever device 6, and the output side of which is a solenoid 5 A of the control valve 5. 5B. The controller 7 is provided with a solenoid 5
By outputting a control signal corresponding to the operation amount S of the operation lever 6A to A and 5B, the direction and flow rate of the pressure oil by the control valve 5 are controlled.

Reference numeral 9 denotes a relief valve. The relief valve 9 is opened when excessive pressure is generated on the discharge side of the hydraulic pump 1 to release the excessive pressure toward the tank 2.

[0007] The hydraulic actuator control device according to the prior art has the above-described configuration. Next, the responsiveness (hereinafter referred to as dynamic characteristics) of the control valve 5 will be described.

First, when the operation lever 6A at the neutral position as shown in FIG. 8 is rapidly tilted to the left (in the direction of arrow C), for example, and stopped at the position of the operation amount S1 shown in FIG. The tilting operation of the operation lever 6A is started at time t1 shown in FIG. 10, and reaches the operation amount S1 with a slight time delay. Then, the command signal Vi output from the operation lever device 6 to the controller 7 sharply rises from the time t1 as shown in FIG. 11, and becomes a constant voltage value when the signal level V1 is reached.

As a result, a control signal V0 having a dynamic response characteristic as shown in FIG.
The control signal V0 starts rising at time t1, and reaches a constant voltage level after reaching a command value Va corresponding to the signal level V1 of the command signal Vi with a predetermined response delay. At this time, the dynamic characteristics of the control valve 5 begin to switch from the neutral position (a) to the switching position (b) at time t1, similarly to the characteristics of the control signal V0 shown in FIG. Reaches the stroke amount corresponding to the command value Va.

[0010]

By the way, according to the above-mentioned prior art, when the operator tilts the operation lever 6A as shown in FIG. 10, the control signal V0 output from the controller 7 to the control valve 5 is shown in FIG. As shown in FIG. 12, a constant dynamic response characteristic is obtained.
, The dynamic characteristic of the control valve 5 is always constant with respect to the command signal Vi output as shown in FIG. A skilled operator feels that the operation of the cylinder device 3 is too slow, and there is a problem that operability and safety cannot be improved.

The present invention has been made in view of the above-mentioned problems of the prior art, and the present invention can appropriately change the responsiveness (dynamic characteristics) of a control valve by an operator's selection. It is an object of the present invention to provide a hydraulic actuator control device capable of improving performance.

[0012]

A feature of the configuration adopted by the present invention to solve the above-mentioned problem is that the flow rate of the pressure oil supplied to the actuator is controlled by a command value based on a command signal output from the operating means. A plurality of characteristic setting means for setting the responsiveness of the control valve to reach a different dynamic response characteristic, and selecting any one of the characteristic setting means, And a selecting means for changing the value.

[0013]

According to the above arrangement, any one of the plurality of characteristic setting means can be selected by operating the selection means, and the time required until the flow rate of the pressure oil supplied to the actuator reaches the command value, that is, The responsiveness of the control valve can be changed according to the operator's preference, skill level, work content, and the like.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those in the prior art shown in FIGS. 8 to 12 are denoted by the same reference numerals, and description thereof will be omitted.

FIGS. 1 to 5 show a first embodiment of the present invention.

In FIG. 1, reference numeral 11 denotes a controller constituted by a microcomputer or the like and used in this embodiment.
The input side of the controller 11 is connected to the operation lever device 6 and a later-described selection switch 12 and the like, and the output side is connected to the solenoids 5A and 5B of the control valve 5. The controller 11 stores the program and the like shown in FIG. 2 in its storage circuit, and performs a dynamic response characteristic switching process of the control signal V0 output to the control valve 5. The storage circuit of the controller 11 stores the characteristic maps and the like shown in FIGS. 3, 4, and 5 in the storage area 11A.

Here, these characteristic maps constitute characteristic setting means, and when the operating lever 6A is tilted as shown in FIG. 10 and a command signal Vi as shown in FIG. The dynamic response characteristics of the control signal V0 are set. Then, in the characteristic map shown in FIG. 3, the control signal V0 starts rising at the time t1, and reaches the command value Va based on the command signal Vi with high responsiveness. FIG.
In the characteristic map shown in FIG. 12, the response is slightly slower than the characteristic map in FIG. 3, and for example, corresponds to the characteristic line shown in FIG. On the other hand, in the characteristic map shown in FIG. 5, the response is further delayed, and the control signal V0 is suppressed to a command value Vb smaller than the command value Va.

Reference numeral 12 denotes a selection switch as selection means manually operated by an operator. The selection switch 12 is a movable contact 12A connected to the power supply 8.
And a first contact 12B, a second contact 12C, and a third contact 12D selectively opened and closed by the movable contact 12A. When the selection switch 12 closes the first contact 12B by the movable contact 12A,
The controller 11 selects the characteristic map shown in FIG.
When the second contact 12C is closed, the characteristic map shown in FIG. 4 is selected, and when the third contact 12D is closed, the characteristic map shown in FIG. 5 is selected.

The hydraulic actuator control device according to the present embodiment has the above-described configuration, and its basic operation is not particularly different from that of the prior art.

The dynamic response characteristic switching process of the control signal V0 by the controller 11 will be described with reference to FIGS.

First, when the processing operation is started, a command signal Vi illustrated in FIG. 11 is read from the operation lever device 6 in step 1 and whether or not the first contact 12B is closed by the selection switch 12 in step 2 is determined. judge. Then, if "YES" is determined in the step 2, the process proceeds to the step 3 to read out the characteristic map shown in FIG. 3 and output the control signal V0 based on the characteristic map. As a result, the control signal V0 rises at time t1 as shown in FIG. 3 and reaches the command value Va with high responsiveness, so that the dynamic characteristics of the control valve 5 also have high responsiveness, and the control valve 5 has the command value V
The stroke amount reaches the stroke amount corresponding to a and the hydraulic oil is supplied and discharged from the hydraulic pump 1 to the cylinder device 3 at a flow rate corresponding to the stroke amount.

If "NO" is determined in the step 2, the process proceeds to a step 5, and the second
It is determined whether or not the contact 12C is closed.
If it is determined to be "S", the process proceeds to step 6. Then, in step 6, the characteristic map shown in FIG. 4 is read out, and a control signal V0 based on this characteristic map is output, whereby
The control valve 5 is caused to stroke from time t1 in accordance with the control signal V0 in FIG. 4, and the switching control is performed slightly later to the stroke amount based on the command value Va. Thereby, the control valve 5
Can be made slightly slower than in FIG. 3, and can be set as the most general dynamic characteristic, for example.

On the other hand, if "NO" is determined in step 5, it means that the third contact 12D is closed by the selection switch 12, so that the process proceeds to step 7 to read the characteristic map shown in FIG. By outputting the control signal V0 based on the map, the control valve 5 is relatively slowly switched to the stroke amount based on the command value Vb in correspondence with the control signal V0 in FIG. As a result, the control valve 5 is slowly switched and controlled to a stroke amount corresponding to the command value Vb lower than the command value Va shown in FIGS. 3 and 4, and even when the operation lever 6A is rapidly operated, the cylinder device 3 can be operated. It is possible to prevent sudden operation.

Therefore, according to the present embodiment, the selection switch 1
2, the first contact 12B, the second contact 12C or the third contact 1
By selectively closing the 2D, one of the characteristic maps shown in FIG. 3, FIG. 4 or FIG. 5 can be selected, and the dynamic characteristic of the control valve 5 when the operation lever 6A is suddenly operated to a desired operation amount S. Can be changed as appropriate. Thereby, the dynamic characteristics of the control valve 5 can be arbitrarily selected according to the preference of the operator, the skill level or the work content, and the operability of the operation lever 6A and the like can be greatly improved. In particular, when the characteristic map shown in FIG. 5 is selected, it is possible to prevent an unskilled operator from operating the cylinder device 3 too quickly,
Safety can be improved.

FIGS. 6 and 7 show a second embodiment of the present invention. The feature of this embodiment is that a control valve 21 of a hydraulic pilot type is provided in the middle of the main pipelines 4A and 4B. Valve 2
The pilot line 23 is connected to a pressure reducing valve type hydraulic pilot valve 22 using the hydraulic pilot portions 21A and 21B as operating means.
A, 23B, and electromagnetic valves 24, 25 as characteristic setting means are provided in the middle of the pilot pipelines 23A, 23B, respectively.

The high-pressure side of the pilot valve 22 is connected to the pilot pump 26, the low-pressure side is connected to the tank 2, and the output side is connected to the pilot lines 23A and 23B. The pilot valve 22 is
By tilting A in the direction of arrow C, pilot pressure as a command signal is generated in the pilot pipelines 23A and 23B, and the control valve 21 is switched from the neutral position (A) to the switching positions (B) and (C). ), The switching is controlled by the stroke amount according to the pilot pressure.

The solenoid valves 24 and 25 are switched by a selection switch 27 as a selection means. When the movable contact 27A of the selection switch 27 is switched to the first contact 27B, the solenoid valves 24 and 25 are both turned on. After being demagnetized, the pilot pressure from the pilot valve 22 becomes the control pressure P0 as a control signal as shown in FIG. In this case, when the operation lever 22A is operated as illustrated in FIG. 10, the control pressure P0 is increased after time t1 with a dynamic response characteristic as indicated by a characteristic line 28 shown in FIG. The pressure Pa is reached with high responsiveness.

Next, the second contact 27C is selected by the selection switch 27.
Is closed, the solenoid valves 24 are excited, so that the pilot pressure from the pilot valve 22 is reduced by the throttle 24A while the hydraulic pilot portion 21A or 2A of the control valve 21 is closed.
1B, the control pressure P0 at this time is boosted later than the characteristic line 28 with a dynamic response characteristic such as a characteristic line 29 shown in FIG. 7, and reaches the command pressure Pa with a response delay. Then, when the third contact 27D is closed by the selection switch 27, each solenoid valve 25 is excited, and the pilot pressure from the pilot valve 22 is throttled by the throttle 25A having a smaller flow area than the throttle 24A. Is increased to the command pressure Pa with a slower dynamic response characteristic as indicated by a characteristic line 30 shown in FIG.

Thus, in the present embodiment thus constructed, the selection switch 27 is connected to the first contact 27B and the second contact 2B.
7C or the third contact 27D is selectively switched to demagnetize and excite the solenoid valves 24 and 25, and the control pressure P0 as the pilot pressure acting on the hydraulic pilot portions 21A and 21B of the control valve 21 is shown in FIG. Characteristic lines 28, 29,
It is possible to increase the voltage with different dynamic response characteristics as shown in FIG. 30, and it is possible to obtain substantially the same operation and effect as in the first embodiment.

In the first embodiment, the selection switch 27 has three contacts 27B, 27C, and 27D, and the movable contact 27A is used to select one of the three contacts 27B, 27C, and 27D. The switch may be provided with two or four or more contacts. In this case, two or four or more characteristic maps are stored in the storage area 11A of the controller 11 as different characteristic setting means. You may.

Also in the second embodiment, the solenoid valves 24, 2
Instead of 5, one or three or more solenoid valves may be used as the characteristic setting means.

[0032]

As described above in detail, according to the present invention, when the operating means is operated, the responsiveness of the control valve until the flow rate of the pressure oil reaches the command value is set as a different dynamic responsiveness. The characteristic setting means is provided so that any one of the characteristic setting means can be selected by the selection means. Therefore, the time until the flow rate of the pressure oil supplied to the actuator reaches the command value, that is, the response of the control valve, Operability can be changed in multiple stages according to the operator's preference, skill level, work content, etc., and the operability of the operating means can be greatly improved.
It produces various effects.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a hydraulic actuator control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a control signal dynamic response characteristic switching process.

FIG. 3 is an explanatory diagram showing a characteristic map of high responsiveness stored in a storage area of a controller.

FIG. 4 is an explanatory diagram showing another characteristic map whose response is slower than the characteristic map of FIG. 3;

FIG. 5 is an explanatory diagram showing another characteristic map in which the response is further delayed than the characteristic map shown in FIG. 4;

FIG. 6 is a hydraulic circuit diagram showing a hydraulic actuator control device according to a second embodiment.

FIG. 7 is a characteristic diagram showing a dynamic response characteristic of a control pressure.

FIG. 8 is a circuit diagram showing a conventional hydraulic actuator control device.

FIG. 9 is a characteristic diagram illustrating a relationship between an operation amount of an operation lever and a command signal.

FIG. 10 is a characteristic diagram illustrating a relationship between a time when the operation lever is suddenly operated and an operation amount.

FIG. 11 is a characteristic diagram showing characteristics of a command signal corresponding to FIG.

12 is a characteristic diagram showing characteristics of a control signal based on the command signal of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic pump (hydraulic source) 3 Cylinder device (actuator) 4A, 4B Main pipeline 5, 21 Control valve 6 Operating lever device (Operating means) 11 Controller 12, 27 Selection switch (Selecting means) 22 Pilot valve (Operating means) 24 , 25 Solenoid valve (characteristic setting means)

Claims (1)

(57) [Claims] 1. An actuator which is operated by pressure oil supplied / discharged from a hydraulic pressure source, and a direction of pressure oil supplied / discharged to / from the actuator is provided in the middle of a pair of main pipelines connecting the actuator and the hydraulic pressure source. A control valve for controlling the flow rate, operated when operating the actuator,
A hydraulic actuator control device, comprising: an operating means for outputting a command signal of a direction and a flow rate of the pressure oil supplied to the actuator, wherein a flow rate of the pressure oil supplied to the actuator is determined based on a command signal output from the operating means. A plurality of characteristic setting means for setting the responsiveness of the control valve until reaching the command value as different dynamic response characteristics, and selecting any one of the characteristic setting means, A hydraulic actuator control device comprising: a selection unit that changes the responsiveness of a valve.