JP2624399B2 - Drive control device for backhoe device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a boom of a backhoe device which is connected to an end of a swivel so as to be able to vertically move and swing.
A boom cylinder for raising and lowering the boom is pivotally connected to a position near the pivot point of the boom on the swivel base and to a middle position of the boom, and a hydraulic oil flow rate to the boom cylinder is determined based on an operation amount of an artificial operating tool. The present invention relates to a drive control device of a backhoe device provided with a control device for performing change control.

[0002]

2. Description of the Related Art Conventionally, in a drive control device for a backhoe device, a control device controls the opening of an electromagnetic hydraulic control valve with respect to a boom cylinder based on an operation amount of an artificial operation lever to change a pressure oil flow rate. The control characteristics are always constant irrespective of the posture of the boom (see, for example, JP-A-2-243828).

[0003]

In the above-mentioned conventional structure, the operator adjusts the drive speed of the boom by adjusting the operation amount of the operation lever according to the work situation. However, when the boom is stood upright toward the swivel table, the angle formed by the boom and the boom cylinder becomes a small angle, and the angular velocity displacement of the boom with respect to the expansion and contraction speed of the boom cylinder becomes large. Therefore, for example, when the vehicle is slightly stopped at a high speed in the upright storage posture and immediately stopped, the shock at the time of the stop becomes large, and there is a disadvantage that the steering stability is lacking.
Therefore, as a method of solving the above-described disadvantage, it is conceivable to reduce the maximum driving speed of the boom cylinder. However, in this case, a breaker or the like is attached to the tip of the backhoe device, and the concrete is destroyed. When performing work or the like, adverse effects such as a shortage of the descending speed occur.
Therefore, an object of the present invention is to solve the above-mentioned disadvantages by rational improvement.

[0004]

According to the present invention, there is provided a drive control device for a backhoe device as described at the beginning.
Upright state detection means for detecting that the boom is in the retracted state toward the swivel table side is provided, and when the upright state detection means is in the detection state, the upright state detection means based on the operation amount of the artificial operation tool is provided. The point is that a pressure oil flow rate suppressing means for reducing the maximum value of the pressure oil flow rate to the boom cylinder is provided.

[0005]

When the boom is in the retracted position toward the swivel table, the maximum value of the hydraulic oil flow to the boom cylinder decreases, so that the operator can operate the artificial operation tool to the maximum operation position. Since the angular velocity displacement of the boom is suppressed to a small value, the shock at the time of stopping is reduced even when the boom is stopped after being slightly displaced. or,
When the boom is not in the retracted state, for example, when the backhoe device is extended forward to perform an operation that requires a high boom lowering speed such as a concrete splitting operation or a pile driving operation, the above-described operation is performed. Since the function of suppressing the pressure oil flow does not work, the work can be effectively performed by the high-speed lowering operation of the boom.

[0006]

Therefore, when the boom is in the upright retracted state, it is not necessary for the operator to operate the boom by adjusting the operation amount of the artificial operation tool while checking the operation state of the boom, and the operation is not required. In a standing position where the dynamic characteristics are likely to be unstable due to the mounting structure of the boom cylinder without sacrificing the boom cylinder mounting structure without sacrificing the boom lowering speed required for ground work. Shock at the time of operation stop can be suppressed, and steering safety has been improved.

[0007]

Embodiments will be described below with reference to the drawings. FIG.
Shows the backhoe. This backhoe has a turntable 2 mounted on a crawler-type traveling machine stand 1 so as to be able to turn all around a vertical axis by driving a turn motor M. The turntable 2 includes a driving unit 3 and a control unit 4. Backhoe device 5
Are connected. The backhoe device 5 comprises a boom 7 pivotally supported by a bracket 6 erected on the swivel 2, an arm 8 pivotally supported at the tip of the boom 7, and a bucket 9 pivotally connected to the arm 8. C
1. Excavation work can be performed by swinging and driving the arm cylinder C2 and the bucket cylinder C3 separately. The boom cylinder C <b> 1 is pivotally connected to a position near the pivot point with respect to the bracket 6 and at an obliquely lower front position and an intermediate position of the boom 7. The distal end of the boom 7 is configured to be bendable so that the arm 8 can be laterally moved and offset while maintaining the parallel posture with respect to the body by driving the parallel link mechanism 10 and the offset cylinder C4.

Next, the driving structure of the backhoe device 5 will be described. As shown in FIG. 1, each of the cylinders C1,
Electromagnetic proportional flow control valves V1, V2, V3, and V4 are interposed in the pressure oil supply passages for C2, C3 and the turning hydraulic motor M, respectively.
The hydraulic system is configured to control the supply amount of hydraulic oil by changing and controlling the duty ratio of the supply pulse current to the control unit.
Reference numerals 1 and 12 (examples of artificial operation tools) are provided so as to be able to swing crosswise in front, rear, left and right, respectively, and the operation amounts in each direction are detected by potentiometers PM1, PM2, PM3, and PM4. Is supplied to the control device 13, which controls the corresponding electromagnetic proportional flow control valves V1, V2, V3 based on the detection values of the potentiometers PM1, PM2, PM3, PM4.
The control is performed by changing the duty ratio of the driving pulse current of V4. That is, when one of the operation levers 11 is operated, for example, in a predetermined direction, the boom cylinder C1 is driven to expand and contract, and when the operation amount is increased, the supply amount of pressurized oil increases, and the cylinder expands and contracts at high speed. The operation in the other direction and the operation of the other operation lever 12 in each direction cause the arm cylinder C2 and the bucket cylinder C, respectively.
3. The turning hydraulic motors M can be driven separately or simultaneously. The offset cylinder C4 is controlled and driven by the switching operation of the electromagnetic proportional flow control valve V5 based on the operation of the operation pedal 14.

At the position of the boom 7 relative to the bracket pivot point, a potentiometer PM5 (an example of a standing state detecting means) for detecting a relative swing angle between the boom 7 and the bracket 6 is provided.
If the detection result of the potentiometer PM5 detects that the boom 7 is in the retracted state toward the swivel base, the pressure on the boom cylinder C1 based on the operation amount of the operation lever 11 is determined. A pressure oil flow suppression means A for reducing the maximum value of the oil flow is provided. The pressure oil flow suppression means A is provided in the control device 13 in the form of a control program, and changes the pressure oil flow control characteristic as follows. In other words, when the detection value of the potentiometer PM5 is in an area where the boom 7 is not in the upright storage posture (for example, when the backhoe device 5 is in a posture that protrudes forward), the boom cylinder C1 with respect to the operation amount of the operation lever 11 is used. As shown by the solid line in FIG. 3, the change characteristic of the pressure oil supply amount changes almost linearly to the maximum operation position, and when the potentiometer PM5 is in the upright storage posture area of the boom 7, FIG. As indicated by the imaginary line, the control characteristic is changed such that the control characteristic is suppressed to a value X2 smaller than the maximum pressure oil flow value X1 in the above-mentioned linear change characteristic in the operation with the predetermined operation amount or more.

In addition, apart from the main control valve V1 for the boom cylinder C1, there is provided a speed increasing sub-control valve V6 for joining pressure oil from a hydraulic pump P2 other than the pressure oil supply pump P1, The speed-up sub-control valve V6 can be switched between a non-speed-up state in which the neutral position is always maintained and a boom speed-up state operated simultaneously with the operation of the main control valve V1 by switching operation of the operation switch SW. It is configured to be able to.

[Alternative Embodiment] The pressure oil flow rate control characteristic is changed by changing the pressure oil flow rate to a constant value when the operation lever 11 is operated at a predetermined value or more, as shown in FIG.
As shown in FIG. 7, the characteristic may be changed to a characteristic in which the change in the pressure oil flow rate with respect to the change in the operation amount of the operation lever 11 changes gradually and linearly.

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 system diagram

FIG. 2 is an overall side view of a backhoe.

FIG. 3 is a characteristic diagram showing a control state.

FIG. 4 is a characteristic diagram showing a control state according to another embodiment.

[Explanation of symbols]

 2 Turntable 5 Backhoe device 7 Boom 11 Artificial operation tool 13 Control device A Pressure oil flow rate suppression means C1 Boom cylinder PM5 Standing state detection means

Claims (1)

(57) [Claims] 1. A boom cylinder (C1) for connecting a boom (7) of a backhoe device (5) to an end of a revolving base (2) so as to be able to vertically move and swing, and for driving a boom (7) up and down.
Is pivotally connected to a position near the pivot point of the boom (7) on the swivel table (2) and to a middle position of the boom (7), and based on an operation amount of the artificial operation tool (11), A drive control device for a backhoe device provided with a control device (13) for changing and controlling the flow rate of pressure oil with respect to (C1), wherein the boom (7) is stood up toward the swivel (2). Is provided, and the upright state detecting means (PM5) is provided.
When 5) is in the detection state, the artificial operation tool (11)
A drive control device for a backhoe device, comprising a pressure oil flow rate suppression means (A) for decreasing a maximum value of a pressure oil flow rate to the boom cylinder (C1) based on the operation amount of (1).