JP2651077B2 - Hydraulic actuator control device for earth moving machine - 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 for an earth-moving machine such as a backhoe, and more particularly, to a hydraulic actuator for driving a working device and an electromagnetic proportional flow control valve of the hydraulic actuator. The present invention relates to a hydraulic actuator control device for an earthmoving machine having flow control means for proportionally controlling the opening degree of an operation lever by supplying a current according to the operation amount of an operation lever.

[0002]

2. Description of the Related Art Conventionally, in a hydraulic actuator control device for an earth moving machine, a control current is supplied to the electromagnetic proportional flow control valve so that a flow rate corresponding to the operation amount can be obtained over the entire operation area of the operation lever. The operation from the neutral stop position to the high-speed operation side region and the operation from the high-speed operation side region to the deceleration side have the same substantially linear change operation characteristics.

[0003]

In the above-mentioned control device, the operation of the spool of the hydraulic control valve for controlling the hydraulic actuator is disadvantageously heavy and difficult to operate. In order to make the operation easier, the operation amount of the operation lever is converted into an electric signal, and the hydraulic actuator is operated using an electromagnetic proportional flow control valve that is proportionally controlled to the opening corresponding to the supply current. It is composed. However, in the above-described conventional structure, since the operation characteristics of the operation lever on the acceleration side and the deceleration side are linear, for example, the operation lever is switched from the operation position of driving the working device at a predetermined high speed state to the neutral position side. When doing, due to the response delay of the control valve or the moving inertia force of the heavy working device, the deceleration operation of the working device may be delayed more than the operation feeling of the operating lever,
Even when it is desired to stop the work equipment at an accurate position, even in the vicinity of the neutral position, since the change characteristics are almost linear, there is a disadvantage that it is difficult to perform a fine adjustment operation of the stop position, and there is room for improvement. there were. An object of the present invention is to eliminate the above disadvantages.

[0004]

According to a feature of the present invention, there is provided a hydraulic actuator control apparatus for an earth-moving machine described at the outset, wherein an operation amount in an operation on an operation speed increasing side of the operation lever and the electromagnetic proportional flow control valve are controlled. While setting the change characteristics with the flow rate to change almost linearly,
In a change characteristic of the operation amount in the operation on the operation speed deceleration side of the operation lever and the flow rate of the electromagnetic proportional flow control valve, the rate of change of the flow rate due to the change of the operation lever is such that the low-speed operation side is higher than the high-speed operation side. The point is that the characteristic is set to change slowly.

[0005]

When the operation lever is switched from the stopped state to the drive operation side, the hydraulic oil flow rate to the hydraulic actuator changes almost linearly in accordance with the operation amount. The speed does not suddenly change, and a smooth acceleration operation adapted to the operational feeling of the driver can be performed. When the operating lever is set in the drive operation area and the operating device is operated to the deceleration side in a state where the operating device is driven, the operating position of the operating lever is changed in an operating region where the operating device is driven at a relatively high speed. Since the change characteristics of the flow rate associated with are relatively steep, it acts to suppress excessive operation due to the inertia force of the working device and the response delay of the control valve, etc., and the operation of the working device can be adapted to the lever operation as much as possible. . And in the operation range driven at relatively low speed,
Since the change characteristic is relatively gentle, a fine adjustment operation for positioning the stop position can be easily performed.

[0006]

Accordingly, while having the advantage that the lever operation can be performed lightly using the electric control type hydraulic control valve, the driving condition of the working device can be minimized by setting the flow control characteristic by the operation lever rationally. Thus, it is possible to provide a control device for a hydraulic actuator which is excellent in operability, so that the control device can be adapted to one adapted to the operator's lever operation feeling.

[0007]

Embodiments will be described below with reference to the drawings. FIG.
Fig. 2 shows a backhoe as an example of an earth moving machine. The backhoe includes a traveling machine base 2 having a crawler traveling device 1.
The swivel 3 is mounted so as to be freely swivelable around the longitudinal axis by driving a hydraulic motor M for swivel, and a backhoe device 4 [an example of a working device] is connected to the swivel 3. 5 is provided. The backhoe device 4 pivotally connects an arm 7 and a bucket 8 to a boom 6 pivotally supported on a swivel 3 so as to be vertically swingable about a horizontal axis, and respectively connects a boom cylinder C1 and an arm cylinder C to each other.
2. It is configured so that the excavation work can be performed by swinging the drive by the bucket cylinder C3. Also, the boom 6 has a base end 6.
a, an intermediate portion 6b and a distal end portion 6c, each of which is pivotally connected around a vertical axis, and the base end portion 6a and the distal end portion 6c are pivotally connected via a link 9 parallel to the intermediate portion 6b. The bucket 8 is configured to be able to move in the left-right direction while maintaining the parallel posture by swinging and driving the intermediate portion 6b by the offset cylinder C4, and the bucket 8 is offset laterally with respect to the boom base end 6a. By being stored on the swivel table 3, the swing operation can be performed with the maximum swing diameter reduced.

The boom cylinder C1, the arm cylinder C2, and the bucket cylinder C as hydraulic actuators
Each of the turning hydraulic motor 3 and the turning hydraulic motor M is configured to be controlled and operated by a pair of left and right operation levers 11 arranged on a control unit 10 provided on the turning table 3 and capable of performing a cross swing operation. More specifically, as shown in FIG.
1, C2, C3 and the swing motor M are each configured to control the hydraulic flow rate by an electromagnetic proportional flow control valve V, and the operation amount of each operation lever 11 in each operation direction is detected by four potentiometers PM. The control device 12 controls the amount of current supplied to each of the electromagnetic proportional flow control valves V based on the detected operation amount. The offset cylinder C4 is configured to supply a flow rate set in advance by operating the operation switch SW. The control device 12 includes a flow control unit A that supplies a current corresponding to the operation amount of the operation lever 11 to proportionally control the opening of the electromagnetic proportional flow control valve V. The change characteristic between the operation amount in the operation and the flow rate of the electromagnetic proportional flow control valve V is set to change substantially linearly, and the operation amount in the operation on the operation speed reduction side of the operation lever 11 and the electromagnetic proportional flow control valve V are set. In the characteristic of change with the flow rate of the flow control valve V, the operation lever 11
Is set such that the rate of change of the flow rate with the change of the speed changes more slowly on the low speed operation side than on the high speed operation side. Less than,
The control operation of the control device 12 will be described. FIG. 2 shows a flow chart for controlling the flow rate by the control device 12. The output of the potentiometer PM is read, and the lever operation speed X is calculated from the change in the output [Step 1,
2]. Then, it is determined whether or not the lever operation is on the acceleration operation side. If the lever operation is in the acceleration direction, the current is supplied to the electromagnetic proportional flow control valve V so that the pressure oil flow to the hydraulic actuator with respect to the lever operation amount changes almost linearly. Control is performed to supply (steps 3 and 4). If the operation is on the deceleration side, as shown in FIG. 3, the rate of change of the flow rate according to the change of the operation lever 11 has a quadratic curve characteristic in which the low-speed operation side changes more slowly than the high-speed operation side. An electric current is supplied to the electromagnetic proportional flow control valve V in accordance with a preset control characteristic [steps 5 and 6]. When the lever operation is changed to the deceleration operation side during the operation to the acceleration side as described above, only when the lever operation speed X is equal to or more than the predetermined value a, the deceleration operation change characteristic as described above is obtained. Switch the flow control to follow. At this time, if the characteristics are moved as they are without a time delay, a shock occurs due to a sudden change in the flow rate. Therefore, when such characteristics are switched, the flow rate is gradually increased by passing a predetermined time based on predetermined map data. Is changed [Steps 8 to 10]. Similarly, when the lever operation is changed to the deceleration operation side during the operation to the deceleration side, only when the lever operation speed X is equal to or more than the predetermined value a,
The flow rate control is switched by gradually changing the flow rate after a predetermined time has elapsed based on the map data determined in advance so as to follow the above-described linear change characteristic [Step 1
1,12].

In the claims, reference numerals are provided to facilitate comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a control block diagram.

FIG. 2 is a control flowchart.

FIG. 3 is a control characteristic diagram

FIG. 4 is a side view of the backhoe.

[Explanation of symbols]

 4 Working device 11 Operating lever A Flow control means V Electromagnetic proportional flow control valve

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yutaro Morishita 64 Ishizukita-cho, Sakai-shi, Osaka Kubota Sakai Works Co., Ltd. (56) References JP-A-2-256901 (JP, A) JP-A-4- 297627 (JP, A)

Claims (1)

(57) [Claims] The working device (4) is configured to be driven by a hydraulic actuator, and an opening of an electromagnetic proportional flow control valve (V) of the hydraulic actuator is adjusted according to an operation amount of an operating lever (11). What is claimed is: 1. A hydraulic actuator control device for an earthmoving machine comprising a flow control means (A) for supplying a current to perform proportional control, wherein an operation amount in an operation on an operation speed increasing side of the operation lever (11) is controlled by the electromagnetic proportional control. The change characteristic of the flow rate of the flow control valve (V) with respect to the flow rate is set so as to change substantially linearly, and the operation amount in the operation of the operation lever (11) on the operation speed reduction side and the electromagnetic proportional flow control valve (V In the change characteristic with respect to the flow rate, the change rate of the flow rate due to the change of the operation lever (11) is set to a characteristic in which the low-speed operation side changes more slowly than the high-speed operation side. Hydraulic actuator control device for earth moving machines.