JPH05195554A - Hydraulic actuator controller in earth-moving machine - Google Patents

Abstract

PURPOSE:To inhibit the generation of a shock resulting from the inertia, etc., of a working device by supplying a flow control valve with currents on the basis of the change characteristics of variable speed smaller than the variable speed of a control lever regardless of the manipulated variable of the control lever when the control lever is changed over at high speed higher than specified speed. CONSTITUTION:A controller 12 reads outputs from potentiometers PM and rotational-quantity detecting sensors S, and an operation-speed arithmetic means B arithmetically operates the variable speed of the positions of operation of control levers 11. When the control levers 11 are worked to the acceleration side at that time, proper current supply increase characteristics to electromagnetic type proportional flow control valves V are set. When lever operation speed is set at a specified position or higher, a current variable-speed control means C increases the quantity of currents fed to the control valves V on the basis of characteristics set until the control levers 11 are stopped. Accordingly, even when the control levers 11 are worked quickly, the supply flow rate of pressure oil to a hydraulic actuator is not augmented rapidly.

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 earthmoving machine such as a backhoe. More specifically, the working device is configured to be driven by a hydraulic actuator, and an electromagnetic proportional flow control valve for the hydraulic actuator is provided. The present invention relates to a hydraulic actuator control device in an earthmoving machine, which is provided with a flow rate control means for proportionally controlling the opening degree of the control lever by supplying a current according to an operation amount of an operation lever.

[0002]

2. Description of the Related Art Conventionally, a hydraulic actuator control device for an earthmoving machine is configured to supply a current corresponding to an operation amount of the operation lever to the electromagnetic proportional flow control valve over the entire operation region. It was

[0003]

The above-mentioned control device is disadvantageous in that manually operating the spool of the hydraulic control valve for controlling the hydraulic actuator is heavy and difficult to perform. In order to facilitate the operation of the hydraulic actuator, 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, the electromagnetic proportional flow control valve is configured to be driven and controlled by supplying a current according to the operation amount over the entire operation area of the operation lever. Since the lever can be operated relatively lightly, for example, when the hydraulic actuator is started from a stopped state or when accelerating from a low speed operation, the operating lever can be switched at high speed. It may end up. Even in such a case, since the electric current corresponding to the lever operation amount is supplied to the electromagnetic proportional flow rate control valve, the hydraulic actuator may suddenly operate to cause a shock. In particular, in the case of a backhoe, there is a high possibility that the above-described shock will occur when the swivel base to which the backhoe device is connected is swung. The present invention aims to eliminate the above-mentioned problems.

[0004]

According to a first aspect of the present invention, there is provided a hydraulic actuator control device for an earthmoving machine, which has a lever operating speed calculating means for calculating a changing speed of an operating position of the operating lever. Only when the change speed by the lever speed calculating means is detected to be equal to or higher than a predetermined value, the electromagnetic wave is changed based on the predetermined change characteristic of the change speed smaller than the change speed regardless of the operation amount of the operation lever. The point is that a current changing speed suppressing means for supplying a current to the proportional flow control valve is provided. Book second
In the characteristic configuration of the invention, in the acceleration side operation of the operation lever, the operation position of the operation lever is closer to the lower speed side,
In the deceleration side operation of the operation lever, the change speed of the supply current in the current change speed suppressing means is set to be large, and the supply current in the current change speed suppressing means increases as the operation position of the operation lever becomes lower. The point is that the change speed of is set to small. The characteristic configuration of the third invention is
An attitude state detecting means for detecting an outwardly protruding attitude state of the work device is provided, and a current change for changing a changing speed of the supply current in the current changing speed suppressing means based on a detection result of the attitude state detecting means. It is equipped with speed changing means.

[0005]

When the operation lever is switched at a high speed of a predetermined speed or higher, the electromagnetic proportional ratio is determined based on the predetermined change characteristic of the change speed smaller than the change speed regardless of the operation amount of the operation lever. Since current is supplied to the flow control valve, even if the operating lever is suddenly operated, the pressure oil supply flow rate to the hydraulic actuator does not suddenly increase, and the occurrence of shock due to the inertia of the working device is suppressed. It will be possible. Then, by changing the change speed of the change characteristic set in advance according to the difference in the operating direction of the operation lever, when the lever switching operation on the acceleration side of the hydraulic actuator is suddenly performed, the stop or Although the work device that operates at low speed is accelerated to the high speed side, the controlled change speed becomes relatively large in the low speed operation region, so it is caused by inertial force while suppressing shock due to sudden acceleration. It is possible to prevent deterioration of responsiveness as much as possible. Further, in the deceleration side operation, when the operating speed of the hydraulic actuator reaches a sufficiently low speed operation range, the controlled change speed becomes relatively small.
It is possible to effectively suppress the shock caused by the rapid current change. Also, when the work device is in the outwardly projecting posture, the static inertial force or the dynamic inertial force with respect to the hydraulic actuator becomes large. Since a shock is likely to occur when decelerating and stopping, it is necessary to change and set appropriate speed change characteristics according to such posture changes. It is possible to further reduce the occurrence of shock.

[0006]

Therefore, while the hydraulic control valve is electrically controlled, the lever operation can be performed easily and lightly, but the operating lever can be rapidly switched during the acceleration / deceleration switching operation of the hydraulic actuator. However, it is possible to effectively prevent the occurrence of shock due to start or stop, and it is possible to provide a hydraulic actuator that can always smoothly operate even when driving a heavy work device. Came to.

[0007]

Embodiments will be described below with reference to the drawings. Figure 8
Shows a backhoe as an example of an earthmoving machine. This backhoe has a traveling platform 2 equipped with a crawler traveling device 1.
In addition to mounting a swivel base 3 around the longitudinal axis by driving a swiveling hydraulic motor M, a backhoe device 4 [an example of a working device] is connected to the swivel base 3, an engine is mounted, and the vehicle travels. The machine base 2 is provided with a dozer device 5. The backhoe device 4 pivotally connects an arm 7 and a bucket 8 to a boom 6 that is pivotally supported on the swivel 3 about a horizontal axis so that the arm 6 and the bucket 8 are pivotally supported, and each of them is a boom cylinder 15, an arm cylinder 16, and a bucket. The cylinder 17 is driven and rocked to perform excavation work. In addition, the boom 6 is divided into a base end portion 6a, an intermediate portion 6b, and a tip end portion 6c, which are pivotally connected to each other around a longitudinal axis, and the base end portion 6a and the tip end portion 6c are connected to the intermediate portion 6b. The bucket 8 is pivotally connected via parallel links 9, and the offset cylinder 18 swingably drives the intermediate portion 6b so that the bucket 8 can move in the left-right direction while maintaining the parallel posture. The vertical upper point of the swinging pivot fulcrum of the boom 6 is set so that the swinging operation can be performed in a state in which the maximum swinging diameter is reduced by laterally offsetting the portion 6a and storing it on the swivel base 3 (see FIG. 9). The ascending side swing movement range of the boom 6 is set so that the center of gravity of the backhoe device 4 can be moved to the inside of the machine body.

The boom cylinder 15, the arm cylinder 16, and the bucket cylinder 1 as hydraulic actuators.
Each of the turning hydraulic motor M and the turning hydraulic motor M is configured to be controlled and controlled by a pair of left and right operation levers 11 which are provided in a control unit 10 provided on the turning base 3 and are capable of swinging in a cross motion. More specifically, as shown in FIG. 1, each of the cylinders 1
5, 16 and 17 and the swing motor M are each configured to control the hydraulic flow rate by the electromagnetic proportional flow rate control valve V, and the operation amount of each operation lever 11 in each operation direction is detected by the four potentiometers PM. The controller 12 controls the amount of current supplied to each electromagnetic proportional flow control valve V based on the detected manipulated variable. The offset cylinder 18 is controlled to supply a predetermined current value by operating the operation switch SW. Further, a rotation amount detection sensor S for detecting the operating state of each hydraulic actuator is provided in the vicinity of the boom 6, the arm 7, the pivot support fulcrum of the bucket 8 and the swivel base 3. The control device 12 supplies a current according to the operation amount of the operation lever 11 to calculate a flow rate control means A for proportionally controlling the opening of the electromagnetic proportional flow rate control valve V and a change speed of the operation position of the operation lever. The lever operation speed calculation means B to be operated and the change speed smaller than the change speed regardless of the operation amount of the operation lever 11 only while detecting that the change speed by the lever speed calculation means B is a predetermined value or more. Current changing speed suppressing means C for supplying a current to the electromagnetic proportional flow rate control valve V based on the predetermined change characteristic, and posture state detecting means D for detecting an outward posture state of the work device, Based on the detection result of the posture state detecting means D, the current changing speed changing means E for changing the changing speed of the supply current in the current changing speed suppressing means C is controlled by a control program format. It is provided. That is, when accelerating or decelerating the operating lever 11, if the lever operating speed is large and the operating position changes abruptly, the increasing / decreasing speed of current supply to the electromagnetic proportional flow control valve V is suppressed. Therefore, it is configured to prevent sudden operation. Specifically, the control operation of the swing motor M as an example of the hydraulic actuator will be described below. As shown in FIGS. 2 and 3, the outputs of the rotary motor drive potentiometer PM and the respective rotation amount detection sensors S are read [step 1], and when the lever operation is started, the lever speed X thereof is calculated [step 2]. , 3], and whether the lever operating direction is operated from the neutral position to the speed increasing side or from the high speed operating position to the speed reducing side [step 4]. When operated to the acceleration side, an appropriate current supply increasing characteristic for the electromagnetic proportional flow rate control valve V is set from the lever operation position at that time [steps 4 and 5].
At this time, for example, based on the characteristics shown in FIG. 4, the lever operation position is vertically divided into three stages, and the value of the change rate of the current is set stepwise in accordance with which of the operation ranges, The change speed is set to be higher as the lever operation position is on the lower speed side. Next, based on the detection result of each rotation amount detection sensor S, it is judged whether or not the backhoe device 4 is in a posture in which the backhoe device 4 is projected to the outside of the body [step 6]. Since the static inertial force is large, the value of the rate of change of the current in the current supply increasing characteristic is changed to the large side and reset so as to prevent a response delay [step 7]. When the lever operation speed X is a high speed of a predetermined value a1 or more, the current to the electromagnetic proportional flow control valve V is based on the characteristics set as described above regardless of the lever operation position until the lever movement operation is stopped. Increase supply [Steps 8-1
0] [see FIG. 5]. When the lever operation speed X is slowly performed at a predetermined value a1 or less, a current corresponding to the lever operation position is supplied to the control valve V to proportionally control the opening [steps 11 and 12]. Then, when the lever operation is operated to the deceleration side, an appropriate current supply reduction characteristic for the electromagnetic proportional flow rate control valve V is set from the lever operation position at that time [step 13]. At this time, for example, based on the characteristics shown in FIG. 6, the lever operation position is vertically divided into three stages, and the value of the change rate of the current is set stepwise in accordance with which of the operation ranges, The changing speed is set to be smaller as the lever operating position is located on the lower speed side. Next, based on the detection results of the rotation amount detection sensors S, it is judged whether or not the backhoe device 4 is in a posture in which the backhoe device 4 is projected to the outside of the body [step 14]. Since the dynamic inertial force is large, the value of the current change speed in the current supply reduction characteristic is changed to the large side and reset so that the deceleration operation can be performed quickly [step 15]. When the lever operation speed X is a high speed of a predetermined value a2 or more, the current to the electromagnetic proportional flow control valve V is based on the characteristics set as described above regardless of the lever operation position until the lever movement operation is stopped. Increase supply [Steps 16-18]
[See FIG. 7]. When the lever operation speed X is slowly performed at a predetermined value a2 or less, a current corresponding to the lever operation position is supplied to the control valve V to proportionally control the opening [steps 19 and 20]. Then, the above control is repeated until it is reset [step 21]. The flow rate control means A is configured by the steps 11 and 19, the lever speed calculation means B is configured by the step 3, the current change speed suppressing means C is configured by the steps 9 and 17, and the step 6 and the step are performed. 1
The posture state detecting means D is constituted by 4 and the step 7
And the step 15 constitutes the current change speed changing means E.

The control described above is not limited to the swing motor M, and may be used for controlling other hydraulic actuators such as the boom cylinder 15.

It should be noted that reference numerals are added to the claims for facilitating the comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a control block diagram.

[Fig. 2] Control flowchart

FIG. 3 is a control flowchart.

[Figure 4] Speed upper limit characteristic diagram during acceleration operation

[Fig. 5] Control characteristic diagram during acceleration operation

FIG. 6 is a speed upper limit value characteristic diagram during deceleration operation.

FIG. 7 is a control characteristic diagram during deceleration operation.

FIG. 8 is a side view of the backhoe in an overhanging posture.

FIG. 9 is a side view of the backhoe in the retracted posture.

[Explanation of symbols]

 4 Working device 11 Operation lever A Flow rate control means B Lever speed calculation means C Current change speed suppression means D Attitude state detection means E Current change speed change means V Electromagnetic proportional flow rate control valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Mukata 64 Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Factory

Claims (3)

[Claims] 1. A working device (4) is configured to be driven by a hydraulic actuator, and an opening of an electromagnetic proportional flow rate control valve (V) of the hydraulic actuator is set according to an operation amount of an operating lever (11). A hydraulic actuator control device for an earthmoving machine equipped with a flow rate control means (A) for supplying an electric current and performing proportional control, wherein a lever operation speed calculation means (calculates a change speed of an operation position of the operation lever (11) ( B) and a change speed smaller than the change speed regardless of the operation amount of the operation lever (11) only while detecting that the change speed by the lever speed calculation means (B) is equal to or more than a predetermined value. A hydraulic actuator for an earthmoving machine, which is provided with a current change speed suppressing means (C) for supplying a current to the electromagnetic proportional flow rate control valve (V) based on a predetermined change characteristic. Data control device. 2. In the acceleration side operation of the operation lever (11), the change speed of the supply current in the current change speed suppressing means (C) becomes higher as the operation position of the operation lever (11) becomes lower. Set it to large and set the operation lever (1
In the deceleration side operation of 1), the operation lever (11)
2. The hydraulic actuator control device for an earthmoving machine according to claim 1, wherein the change speed of the supply current in the current change speed suppressing means (C) is set to be smaller as the operation position of is closer to the lower speed side. 3. An attitude state detecting means (D) for detecting an outwardly projecting attitude state of the working device (4), and the current change based on a detection result of the attitude state detecting means (D). The hydraulic actuator control device for an earthmoving machine according to claim 1 or 2, further comprising a current changing speed changing means (E) for changing a changing speed of the supplied current in the speed suppressing means (C).