JP2695873B2 - Backhoe swing control device - Google Patents

Description

The present invention relates to a backhoe swing control device.

(Background Art) A backhoe is provided with a swing table that can swing about a vertical axis on a vehicle body, a bucket is attached to the swing table via a boom and an arm, and the swing table and the boom are operated by an operation lever of a control box. , An arm and a bucket.

When the rocking table is rocked, the conventional control device operates the operation lever in the left-right direction, and controls the rocking speed in proportion to the tilt angle, and therefore, rocks to near the end point. If so, it was necessary to reduce the tilt angle of the operation lever and reduce the speed.

(Problems to be Solved by the Invention) Conventionally, as described above, the swing speed is controlled in accordance with the tilt angle of the operation lever.
In some cases, the rocking table rocked to the end point at high speed, and the boom collided violently with the end point stopper. Therefore, the stop position of the vehicle body may be displaced due to the impact during the work, or depending on the positions of the boom, the arm, and the bucket, they may hit the cylinder of the outrigger and be damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been provided for the purpose of judging when the swing table swings to near the end point and automatically reducing the swing speed.

(Means for Solving the Problems) According to the present invention, as a means for solving the problems, there is provided a backhoe in which the swing speed of the swing base 15 is controlled in accordance with the tilt angle of the operation lever 28. A detector 24 for detecting the swinging position of the base 15 and a deceleration range discrimination for judging that the base 15 is in a deceleration range E near the end point based on a signal from the detector 24 when the base 15 swings to the left and right end sides Means 35 and issues an altitude maintenance command when the swing speed a is equal to or less than the designated deceleration speed b in the deceleration range E, and issues a deceleration command to reduce the speed to a certain speed when the swing speed a is greater than the designated deceleration speed b. Speed command means 37.

(Operation) When operating the operating lever 28 to swing the rocking table 15 toward the end point, the detector 24 detects the rocking position, and if it reaches the deceleration area E near the end point, the deceleration area discriminating means is used. 35 determines it. Then, the speed command means 37 determines the magnitude of the current swing speed a and the designated deceleration speed b, and issues a deceleration command when the swing speed a is high. Therefore, when the swing table 15 enters the deceleration range E, even if the tilt angle of the operation lever 28 is large, the swing table 15 is automatically decelerated irrespective of the inclination angle, and can be smoothly stopped at the end point.

Embodiment Hereinafter, the present invention will be described in detail with reference to the illustrated embodiment. In FIG. 4, reference numeral 1 denotes a tractor body, 2 denotes a front wheel, and 3 denotes a rear wheel. 4 is a steering wheel and 5 is a driver's seat.

Reference numeral 6 denotes a front loader mounted on the front of the tractor vehicle body 1, which includes a mast 7 mounted on the left and right sides of the tractor vehicle body 1, and a boom 8 pivotally mounted on the upper end of the mast 7 so as to be vertically movable. It has a boom cylinder 9 for raising and lowering the boom 8, a bucket 10 pivotally attached to the tip of the boom 8, and a bucket cylinder 11 for rotating the bucket 10.

Reference numeral 12 denotes a backhoe mounted on the rear end of the tractor body 1, a frame 13 mounted on the tractor body 1, and a swing table pivotally mounted on the frame 13 so as to be swingable about a longitudinal axis 14. 15 and
A boom 16 pivotally mounted on a rocking table 15 so as to be vertically movable, and a boom
Arm 17 pivotally attached to the tip of 16 and arm 17
Bucket 18 pivotally attached to the tip of
It has a control box 19 and a driver's seat 20 provided above. The swing table 15 is supported by a pair of upper and lower brackets 21 projecting rearward from the machine frame 13 via a longitudinal axis 14 as shown in FIG. 5, and the machine frame 13 and the swing table 21 And a pair of left and right swing cylinders 22 and 23
Rocking operation. A detector 24 for detecting the swing position of the swing table 15 is attached to the swing table 15. boom
The boom cylinder 25 allows the arm 16 to move up and down, the arm 17 allows the arm cylinder 26 to bend, and the bucket 18 allows the bucket cylinder 27 to rotate. The machine casing 13 is provided with outriggers 30 on both left and right sides.

As shown in FIG. 6, two operation levers 28 and 29 that can swing back and forth and right and left are provided side by side on the upper surface side of the control box 19. When the operation lever 28 is operated left and right, the swing base 15 swings left and right, and when the operation lever 28 is operated back and forth, the boom 16 moves up and down. Operation lever
In the case of 29, the bucket 18 squeezes and dumps when operated left and right, and the arm 17 expands and contracts when operated back and forth.

As shown in FIG. 1, the operation lever 28 activates a swing command potentiometer 31 by an operation in the left-right direction. The potentiometer 31 is connected to a direction discriminating means 32 and a speed signal generating means 33. Connected. The direction discriminating means 32 compares the output voltage from the potentiometer 31 with a reference value, and discriminates the swing direction according to the magnitude of the output voltage.The speed signal generating means 33 is proportional to the tilt angle of the operating lever 28 based on the output voltage. To generate a speed signal.

The detector 24 comprises a potentiometer 34 and the like as shown in FIG. 1, and this potentiometer 34 is connected to a deceleration range discriminating means 35, a speed discriminating means 36, a speed command means 37 and the like. As shown in FIG. 3, the deceleration range determining means 35 includes a swing range D of the swing table 15 from the center position B to the end points C at the left and right ends.
The constant deceleration range E near the end point is determined based on the output from the potentiometer 34. The speed discriminating means 36 discriminates the current swing speed a at the time of the swing from the change in the output from the potentiometer 34. Speed command means 37
Compares the current swing speed a from the speed discriminating means 36 with the designated deceleration speed b connected to the designated deceleration speed setting means 38. When the oscillation speed a is equal to or less than the designated deceleration speed b, the speed maintenance command is issued. When the swing speed a is higher than the designated deceleration speed b, a deceleration command for decelerating to a certain speed is issued. Each of these means 32, 33, 35, 36, 37, 38 is constituted by a central processing unit of a microcomputer 39 or the like. Numeral 40 is a flow rate proportional solenoid valve for controlling the swing cylinder 23, and 41 is a drive circuit for selectively driving a pair of solenoids of the solenoid valve 40, and the drive circuit 41 decelerates to a certain speed when a deceleration command is issued. The control part for making it perform is built in.

Next, the operation of the above configuration will be described with reference to the flowchart of FIG.

When swinging the swing table 15 at the center position B to the left, when the operation lever 28 is tilted to the left, the potentiometer 31 is activated, and the direction determination means 32 determines the swing direction (step ). Then, since the speed signal generating means 33 generates a speed signal proportional to the tilt angle of the operation lever 28, the solenoid valve 40 is driven via the drive circuit 41, and the swing of the pair of right and left swing cylinders 23 causes the swing. The table 15 swings leftward at a speed proportional to the tilt angle. On the other hand, since the left swing from the center position B to the end position C, the deceleration area determination means 35 sequentially reads the swing position detected by the detector 24 (step), and the deceleration area determination means 35 It is determined whether the 15 swing position is the manual control range F or the deceleration range E (step). When the swing table 15 reaches the vicinity of the end point and enters the deceleration range E, the speed determining means 36 determines the current swing speed a (step). The deceleration designated speed b is read from the deceleration designated speed setting means 38 (step), and the speed command means 37 determines the magnitude relationship between these speeds a and b (step).
If the current speed a is lower than the designated speed b, the speed command means 37 issues a speed maintenance command (step), so that the rocking table 15 rocks to the end point at that speed,
If the current speed a is higher than the designated speed, the speed command means 37 issues a deceleration command (step), and the drive circuit 41 operates to reduce the swing speed to a constant speed equal to or lower than the designated speed b. Therefore, even if the inclination angle of the operation lever 28 is large, the vehicle is automatically decelerated when it enters the deceleration range E.
15 stops at a low speed against the end point stopper.

 Note that each control means may be configured as hardware.

(Effects of the Invention) According to the present invention, the detector 24 that detects the rocking position of the rocking table 15 and the rocking position detected by the detector 24 when rocking to the left and right end sides are used. Deceleration range determining means 35 for determining that is in the deceleration range E near the end point; speed determining means 36 for determining the current swing speed a from the change in the swing position detected by the detector 24; b, and compares the current swing speed a determined by the deceleration discriminating means 36 with the deceleration designated speed b set by the deceleration designated speed setting means 38. Speed command means 37 for issuing a speed maintenance command when the swing speed a is equal to or less than the designated deceleration speed b, and issuing a deceleration command for decelerating to a constant speed when the swing speed a is greater than the designated deceleration speed b. Therefore, even if the tilt angle of the operation lever 28 remains large, if the swing table 15 enters the deceleration E, It can be dynamically deceleration. There is no fear that the stop position is shifted or the cylinder of the outrigger is damaged unlike the related art, and the steering becomes easy.

The speed command means 37 compares the current swing speed a determined by the speed determination means 36 with the designated deceleration speed b set by the designated deceleration speed setting means 38, and determines the swing speed within the deceleration range E. When a is equal to or less than the designated deceleration speed b, a speed maintenance command is issued, and when the swing speed a is greater than the designated deceleration speed b, a deceleration command to reduce the speed to a certain speed is issued. Compare the speed a with the designated deceleration speed b,
It is sufficient to determine whether to issue a speed maintenance command or a deceleration command according to the magnitude of the swing speed a with respect to the designated deceleration speed b.
The control becomes very simple, so that the operation can be performed reliably and stably with few malfunctions, and the configuration of the control means can be made simple and inexpensive. Further, the speed command means 37 only issues a deceleration command for decelerating to a certain speed when the swing speed a is higher than the designated deceleration speed b, and does not decelerate when the swing speed a is smaller than the designated deceleration speed b. Even when the vehicle enters the deceleration range E, the vehicle is not decelerated excessively and a certain speed can be maintained, so that the working efficiency does not extremely deteriorate.

[Brief description of the drawings]

1 shows an embodiment of the present invention, FIG. 1 is a block diagram of a control system, FIG. 2 is an operation flowchart thereof, FIG. 3 is an explanatory diagram of a swing range, FIG. FIG. 5 is a plan sectional view of the swinging part, and FIG. 6 is a layout view of the operation lever. 1 ... body, 14 ... longitudinal axis, 15 ... swing table, 16 ... boom, 28 ... operating lever, 31, 34 ... potentiometer, 3
2 ... direction discriminating means, 35 ... deceleration area discriminating means, 36 ... speed discriminating means, 37 ... speed commanding means.

Claims (1)

(57) [Claims] 1. A backhoe in which the swing speed of the swing base 15 is controlled in accordance with the tilt angle of the operation lever 28, a detector 24 for detecting the swing position of the swing base 15, At the time of swinging, the deceleration range determining means 35 for determining that the swing table 15 is in the deceleration range E near the end point based on the swinging position detected by the detector 24, and the change of the swinging position detected by the detector 24 Speed discriminating means 36 for discriminating the current swing speed a, deceleration designated speed setting means 38 for setting deceleration designated speed b, current swing speed a determined by the speed discriminating means 36 and the deceleration designated speed setting The deceleration designated speed b set by the means 38 is compared, and a speed maintenance command is issued when the swing speed a is equal to or less than the designated deceleration speed b in the deceleration range E, and when the swing speed a is greater than the designated deceleration speed b. Speed command means 37 for issuing a deceleration command for decelerating to a certain speed. Backhoe swing control device according to.