JPH10245866A - Shovel device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the attitude of a bucket accurately by installing a speed control means controlling the working speed of a bucket actuator so that target angular velocity required for maintaining an anti-car body attitude in the bucket is measured by a bucket sensor to a controller. SOLUTION: The angular velocity of a boom is measured by a boom sensor 27 while target angular velocity required for maintaining a specified anti-car body attitude in a bucket is obtained on the basis of the angular velocity by artificially controlling the boom at the time of control, in which the bucket is kept in the specified anti-car body attitude. A speed control means D drives a bucket cylinder C2 as a bucket actuator so as to obtain the target angular velocity, and the working speed of the bucket cylinder C2 is controlled so as to measure the target angular velocity by a bucket sensor 28. Accordingly, since control based on speed is conducted, the attitude of the bucket can be controlled accurately even when the boom is worked in any manner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boom actuator for driving a boom to swing and a bucket to swing at a tip end of a boom supported to swing up and down with respect to a vehicle body. A bucket actuator that measures the amount of swing of the boom with respect to the vehicle body, and a bucket sensor that measures the amount of swing of the bucket with respect to the boom. The present invention relates to a shovel device having a control device for controlling a posture with respect to a vehicle body, and more particularly, to an improvement in technology for automatically controlling a posture of a bucket in conjunction with operation of a boom.

[0002]

2. Description of the Related Art Conventionally, a shovel device having the above-described configuration includes a sensor for measuring a swinging posture of a boom with respect to a vehicle body and a sensor for measuring a swinging posture of a bucket with respect to the boom. There has been proposed a method in which the swinging posture of the bucket for maintaining the opening of the bucket in the horizontal posture based on the swinging posture of the boom is set to a target angle and controlled.

[0003]

Considering the operation of moving earth and sand with a shovel device, the vehicle is moved forward with the boom lowered and the opening of the bucket directed toward the front of the vehicle. And then scoop up the earth and sand, after which the opening of the bucket is turned upward and the bucket is lifted by raising the boom to move the car body,
In this operation, when the bucket is lifted by the raising operation of the boom, maintaining the horizontal state of the opening of the bucket reduces the spilling of earth and sand.

However, in order to maintain the opening of the bucket in a horizontal position, the conventional swing control of the bucket based on the swing angle of the boom is performed. Because the control form is set, if the control is performed during the operation of the boom, the posture of the boom is often changed at the timing when the bucket reaches the target posture, and it is not only difficult to perform accurate control, In some cases, smooth control cannot be performed.

It is an object of the present invention to rationally configure a shovel device capable of accurately and smoothly controlling the posture of a bucket, such as maintaining the opening of the bucket in a horizontal posture even when the operation of the boom is continued. On the point.

[0006]

According to a first aspect of the present invention, as described at the outset, a boom swingably moves up and down with respect to a vehicle body. A boom sensor that supports the bucket and drives the boom to swing and a bucket actuator that drives the bucket to swing, the boom sensor measures the swing amount of the boom with respect to the vehicle body, and the bucket sensor measures the swing amount of the bucket with respect to the boom A shovel device having a control device for controlling the attitude of the bucket relative to the vehicle body by driving the bucket actuator when the boom actuator is actuated based on the measurement result, wherein the angular velocity during the artificial control of the boom is signaled from the boom sensor. Based on the measurement result, and based on the measurement result, the target required for the bucket to maintain the posture with respect to the vehicle body. Seeking speed, there speed control means for controlling the operating speed of the bucket actuator to the target angular velocity is measured by the bucket sensor that are provided in the control device, its operation is as follows.

According to a second feature of the present invention (claim 2), in claim 1, the attitude of the bucket relative to the vehicle body deviates from a preset target attitude based on the measurement results of the boom sensor and the bucket sensor. In this case, the control operation of the control device is set so that the control of the correction control means for driving the bucket actuator to operate the attitude of the bucket to the target attitude is performed instead of the control of the speed control means. The operation is as follows.

A third feature of the present invention (claim 3) is that, in claim 2, the control amount is large by comparing the control amount of the bucket actuator in the speed control means with the control amount of the bucket actuator in the correction control means. The point is that the control operation of the control device is set so as to select and perform the control on the side, and the operation is as follows.

According to the first feature, during the control for maintaining the bucket in a predetermined posture with respect to the vehicle body, the boom sensor measures the angular velocity of the boom by artificially controlling the boom. A target angular velocity required for the bucket to maintain a predetermined body attitude with respect to the vehicle body is determined based on the calculated value. The speed control means drives the bucket actuator to obtain the target angular velocity, and the bucket sensor measures the target angular velocity. This controls the operation speed. That is, as compared with the conventional example, in which the control based on the speed is performed according to the speed of the boom, the speed of the boom is different from that of the conventional example, in which the control based on the speed is performed so that the attitude of the boom and the attitude of the bucket at a specific timing correspond to each other. Even when the bucket is operated, the bucket attitude can be controlled with high accuracy, and further, since the angular velocity at the time of the bucket operation is fed back, the control precision can be further increased.

According to the second feature, even when the attitude of the bucket with respect to the vehicle body deviates from the target attitude for some reason during control by the speed control means, the correction control means drives the bucket actuator to change the bucket attitude. This makes it possible to maintain the vehicle body posture at the target posture.

According to the third feature, at the time of control, the control amount of the bucket actuator by the speed control means and the control amount of the bucket actuator by the correction control means are compared, and the control on the larger side by the control device is automatically selected. Therefore, the bucket can be maintained at the target posture without any special operation by the operator.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, an agricultural tractor is configured by arranging an engine 4 at a front position of a vehicle body 3 having a front wheel 1 and a rear wheel 2, and arranging a steering handle 5 and a driver seat 6 at a central portion. ing. A shovel device A is provided at a front position of the tractor via an auxiliary frame 7. The auxiliary frame 7 is detachably connected to and fixed to the body frame of the tractor, and the shovel device A is supported on the auxiliary frame 7 so as to be separable.

As shown in FIGS. 1 and 2, the shovel device A swings around an intermediate frame 11 which is detachably attached to the auxiliary frame 7 and a boom axis 12 which is oriented laterally with respect to the intermediate frame 11. A pair of left and right booms 13 that are movably supported, a bucket 15 that is swingably supported around a bucket shaft 14 in a lateral position at the distal end of the boom 13, and the boom 13 that is driven up and down with respect to the vehicle body 3 A pair of left and right double-acting boom cylinders C1 as a boom actuator, and a bucket 15
And a pair of left and right double-acting bucket cylinders C2 as bucket actuators for driving and swinging.

The bucket 15 includes a bracket 18 supported at the end of a boom so as to be swingable about the bucket shaft 14.
The swing link 21 has a hitch 19 fixedly mounted on the bucket 15 detachably supported via a pin, and is supported at the tip end of the boom so as to be swingable about a swing shaft 20 in a lateral posture.
And a support shaft 22 in a sideways posture on the bracket 18.
A pivot 23 is pivotally connected to a rod 23 swingably supported therearound via an intermediate shaft 24 in a lateral posture, and the bucket cylinder C2 is interposed between the intermediate shaft 24 and an intermediate position of the boom 13, A boom cylinder C1 is interposed between the intermediate frame 11 and an intermediate position of the boom 13.

As shown in FIG. 1, an operation lever 26 for controlling the shovel device A is disposed at a position in front of the driver's seat 6, and a boom with respect to the vehicle body 3 around the boom shaft 12 at a position coaxial with the boom shaft 12. 13 is provided with a potentiometer-type boom sensor 27 for measuring the amount of rotation, and a potentiometer-type bucket sensor 28 for measuring the swing amount of the swing link 21 at a position coaxial with the swing shaft 29.

As shown in FIG. 4, a control system of the shovel device A is constructed. In this control system, a plurality of operation positions and operation amounts of the operation lever 26 are controlled with respect to a control device 29 having a microprocessor. The signal from the lever sensor 30 to be measured and the lever switch 3 provided on the operation lever 26
1, a signal from the boom sensor 27, and a signal from the bucket sensor 28 are formed, and a solenoid of an electromagnetic proportional boom control valve V1 for controlling the boom cylinder C1 is provided. A system for outputting a control signal to a solenoid of an electromagnetic proportional bucket control valve V2 for controlling the bucket cylinder C2 is formed.

The boom control valve V1 and the bucket control valve V
2 has a proportional relationship set so that the opening degree increases as the current value supplied to the solenoid increases, and the control device 29 adjusts the duty ratio of the intermittent signal to adjust the P.
The control operation is set so as to adjust the value of the control current according to the WM equation.

The shovel device A includes the operation lever 2
By the operation of 6, the boom cylinder C1 and the bucket cylinder C2
To raise and lower the bucket 15,
5 is set to the scooping position, the opening 15A of the bucket 15 is set to the horizontal position, and the bucket 15 is switched to the dumping position. In the present invention, when the lever switch 31 is turned ON, The control device 29 controls the opening of the bucket 15
The control operation is set to perform control (hereinafter, referred to as a horizontal control routine) for automatically maintaining A in a horizontal posture with respect to the vehicle body 3.

This horizontal control routine is set as a subroutine in the operation of the control device, and the operation is set as shown in the flowchart of FIG. That is, in this control, first, the signal value of the boom sensor 27 is input at predetermined intervals and is subtracted, so that the boom angular velocity ω
s, and the signal value from the bucket sensor 28 at the time when the boom angular velocity ωs is measured is measured as the bucket sensor angle θt, and is measured by the bucket sensor 28 based on the measured values ωs, θt and the memory data. The target angular velocity ωd to be performed is set (# 101, # 102 steps).

More specifically, when the boom 13 operates at a constant angular speed, the bucket 15 is operated at a predetermined angular speed to control the opening 15A of the bucket 15 to be horizontal. In the device A, since the bucket sensor 28 is configured to measure the swing amount of the bucket 15 from the swing amount of the swing link 21, even when the bucket 15 is operated at a fixed angular velocity, the bucket sensor 28 is It changes with a predetermined characteristic corresponding to the moving angle (this characteristic can be expressed by a quadratic function).
The bucket sensor 1 is used to maintain the opening 15A of the bucket 15 in a horizontal posture based on the two measured values ωs, θt and memory data set in advance to specify the characteristics.
5, the value of the target angular velocity ωd to be measured is obtained and set.

The memory data is data held in a memory (not shown) of the control device 29, and the bucket sensor angle θt is a value measured by the bucket sensor 28.
It does not represent the actual swing angle of the bucket 15 with respect to the boom 13.

Next, the angular velocity ωt of the bucket sensor 28 is measured by inputting and subtracting the signal value of the bucket sensor 28 at predetermined intervals, and the angular velocity ωt is compared with the target angular velocity ωd to calculate a deviation. At the same time, based on this deviation, the opening Cv is set in accordance with the characteristic that the larger the deviation is, the larger the opening of the bucket valve V2 is, and the value is held in the register of the microprocessor or the memory of the control device 29 (# 103, # 104 steps).

Next, when the boom 13 is in the posture of the boom angle θs based on the boom angle θs measured by the boom sensor 27, measurement is performed by the bucket sensor 28 to set the opening of the bucket 15 to the horizontal posture. The target angle θd is set, and at the same time, the bucket angle θt measured by the bucket sensor 28 is measured. Based on the deviation between the respective values θd and θt, the opening degree of the bucket valve V2 increases as the deviation increases. The opening degree Cp is set by the characteristic, and the value is held in the register of the microprocessor or the memory of the control device 29 (Steps # 105 to # 107).

As described above, the target opening Cv of the bucket valve V2 is set in the processing for controlling the angular velocity of the bucket 15, and the target opening Cv for the bucket valve V2 is set in the processing for controlling the attitude of the bucket 15. After Cp is set, the values of the opening Cv and the opening Cp are compared to select the larger opening, and the control current is supplied to the solenoid of the bucket valve V2 so as to obtain the selected opening. It is supplied (steps # 108 to # 110). After the bucket valve V2 is controlled, the bucket 15 changes its attitude by the driving force of the bucket cylinder C2,
In this attitude change state, the larger the deviation is, the larger the valve opening is, and each cylinder is operated at a high speed. By repeating the process of the horizontal control routine, the deviation is reduced. Feedback control is performed. In this control, # 101
Steps # 104 to # 109 constitute the speed control means D of claim 1, and steps 105 to # 107 and # 110 constitute the correction control means E of claim 2.

As described above, in the present invention, # 101 to # 1
Feedback control for swinging the bucket 15 at a speed necessary to maintain the opening 15A of the bucket 15 horizontal based on the angular velocity of the boom 13 during the raising / lowering operation of the boom 13 as shown in the process of step 04, # 105-
As shown in the process of step # 107, the bucket 1 is moved based on the swing angle of the boom 13 when the boom 13 is raised and lowered.
The control operation is set so that either one of the feedback control and the feedback control for swinging the bucket 15 by an amount necessary to maintain the opening 15A in the horizontal position can be performed. By setting a selection rule to execute the side that greatly increases the opening of the valve V2, smooth operation by speed control is enabled, and at the same time, the braking of the attitude control of the bucket 15 can be improved by the attitude control. ing.

In particular, for example, when performing an operation of scooping and transferring earth and sand, as shown in FIG.
Immediately after scooping the earth and sand into the bucket 15 by moving the vehicle body 3 with the opening 15A of
Is turned on, the horizontal control routine can be executed. When the boom 13 is hardly operated when the lever switch 31 is turned on, the bucket 15 is turned on.
For setting horizontal opening 15A (# 105 to # 10)
Opening Cp of the bucket valve V2 set in step 7)
Is necessarily larger than the opening Cv of the bucket valve V2 set in the speed control process (steps # 101 to # 104) for maintaining the opening 15A of the bucket 15 horizontal. As a result of the priority control for setting the posture, the bucket cylinder C2 is controlled so that the opening 15A of the bucket 15 is oriented to the horizontal posture, and during this control, the boom 13 is moved as shown in FIG. Even when the control for raising the boom 1 is performed, the operation of the bucket cylinder C2 in the direction in which the opening 15A of the
As a result of the speed control for maintaining the opening 15A of the bucket 15 horizontal based on the speed of No. 3, the attitude of the bucket 15 is smoothly controlled to enable the work without falling of the earth and sand. Further, as shown in FIG. 2C, after the bucket 15 reaches the required height, the horizontal control is released by turning off the lever switch 31 and the bucket 15 is dumped by operating the operation lever 26. Then, the earth and sand in the bucket 15 can be discharged.

[Other Embodiments] In the present invention, in addition to the above-described embodiment, for example, a bucket sensor can be arranged on the axis of a swinging shaft of a bucket. It is also possible to configure with. Further, the present invention can be applied to control for maintaining the bucket in a posture other than horizontal.

[0028]

Therefore, a shovel device which can smoothly and precisely control the opening of the bucket in a predetermined posture even when the operation of the boom is continued has been rationally constituted (claim 1). Further, the accuracy of the posture of the shovel with respect to the vehicle body can be improved by the correction control (claim 2), and the accuracy of the posture of the shovel with respect to the vehicle body can be improved by automatic selection without a special operation by the operator. (Claim 3).

[Brief description of the drawings]

FIG. 1 is a side view of a tractor provided with a shovel device.

FIG. 2 is a side view continuously showing an operation mode of a bucket during control.

FIG. 3 is a perspective view of an operation lever.

FIG. 4 is a block circuit diagram of a control system.

FIG. 5 is a flowchart showing a control operation.

[Explanation of symbols]

 3 Body 13 Boom 15 Bucket 27 Boom Sensor 28 Bucket Sensor 29 Controller C1 Boom Actuator C2 Bucket Actuator D Speed Control Means E Correction Means ωd Target Angular Speed ωs Angular Speed

Claims (3)

[Claims] 1. A boom actuator for swingably driving a boom and a bucket actuator for swingably driving a boom at a tip end of a boom supported for swinging up and down with respect to a vehicle body. And controlling the attitude of the bucket with respect to the vehicle body by driving the bucket actuator when the boom actuator is actuated based on the measurement results of the boom sensor that measures the swing amount of the boom with respect to the vehicle body and the bucket sensor that measures the swing amount of the bucket with respect to the boom. A shovel device including a control device, wherein the angular velocity during artificial control of the boom is measured based on a signal from the boom sensor, and the bucket is required to maintain the posture with respect to the vehicle body based on the measurement result. A target angular velocity is obtained, and before the target angular velocity is measured by the bucket sensor, Shovel speed control means for controlling the operating speed of the bucket actuator are provided to the controller device. 2. When the attitude of the bucket relative to the vehicle body deviates from a preset target attitude based on the measurement results of the boom sensor and the bucket sensor, the bucket actuator is driven to change the attitude of the bucket to the target attitude. 2. The shovel apparatus according to claim 1, wherein the control operation of the control device is set so that the control of the correction control means operated in place of the control of the speed control means is performed. 3. The control operation of the control device is performed so as to select a control having a larger control amount by comparing a control amount of a bucket actuator in the speed control unit with a control amount of the bucket actuator in the correction control unit. The shovel device according to claim 2, wherein the shovel device is set.