JP2617566B2 - Backhoe safety mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention is a small swivel type in which a part of a boom, an arm, and a bucket can be folded on a plane occupied by a crawler type traveling device, and can be turned in this state. It relates to a safety device in a backhoe.

(B) Prior art The safety mechanism of a small swing type backhoe has been filed by the same applicant as in Japanese Patent Application No. 63-100595.

(C) Problems to be Solved by the Invention The present invention is intended to solve the problem that the bucket interferes with the cabin space where the operator lives when the bucket is stored when the swing is automatically enabled as in the above-mentioned prior application. The safety device is provided two or three times so that there is no safety device.

(D) Means for Solving the Problems The object of the present invention is as described above. Next, a configuration for achieving the object will be described.

A switching valve is provided between the manual control valve and the actuator to detect and calculate the intrusion of the bucket into the set danger zone, close the switching valve, and, based on the detection result of the emergency detector, provide a pilot to the switching valve. An electromagnetic safety valve for releasing the pressure supply and closing the switching valve is provided.

Further, an ultrasonic sensor constituting the emergency detector is arranged in front of the driver's seat, and a touch sensor constituting the emergency detector is arranged on the side of the driver's seat.

In addition, a rotation angle detector that detects the rotation position of the boom, swing frame, or arm is interposed between the pivot shaft and a detector mounting body that is loosely fitted to the pivot shaft and fixed to the rotation side. The pin at a position away from the pivot shaft axis is fitted and engaged with a slot provided in a slot arm protruding from the center of rotation of the rotation angle detector.

(E) Embodiment The purpose and configuration of the present invention are as described above, and the configuration for achieving the object will be described below.

FIG. 1 is a side view of a small turning backhoe, and FIG. 2 is a plan view of the same.

An earth removal plate 10 is provided on one of the front and rear sides of the crawler traveling device 11 so as to be able to move up and down. In addition, a swivel bearing is interposed on the crawler traveling device 11 to support the body frame.

A boom 6 is pivotally supported at the front of the body frame by a boom actuator 38 so as to be vertically rotatable, and a swing frame 22 that enables swinging to the left and right is pivotally supported at the tip of the boom 6. The swing actuator 3 swings the swing frame 22 right and left. The arm 4 is attached to the tip of the swing frame 22 by an arm actuator.
The bucket 1 pivotally supported by the distal end of the arm 4 is scooped and rotated by a bucket actuator 37.

In order to detect the rotation positions of the boom 6, the swing frame 22, and the arm 4, a boom rotation angle detector 17 is provided at the base of the boom actuator 38, and the swing frame rotation detector 16 is provided at the base of the swing rod 23. And an arm rotation detector 15 is provided at the rotation base of the arm 4.

The arm rotation angle detector 15, the swing frame rotation angle detector 16, and the boom rotation angle detector 17 are configured by potentiometers, and the mounting configuration of the potentiometers will be described later.

The cabin 12, the seat 8, and the swing operation pedal 29 are arranged on the body frame. 9a is a boom operation lever, and 9b is an arm operation lever.

Then, the bucket 1 can swing by moving in parallel from side to side at the swing frame 22. When the bucket 1 is pulled in the direction of the cabin 12 in the swung state, the cabin 12 is broken, and the operator can follow the wound. When the bucket 1 reaches the danger area line a, the bucket 1 automatically returns to the position 1 'on the path to the storage position 1 "without operating the swing operation pedal 29. It is composed.

FIG. 3 is a side view of the cabin 12, FIG. 4 is a plan view thereof, and FIG. 5 is a front view thereof.

3 to 5, in the case where the bucket 1 approaches from the front side of the cabin 12, before the bucket 1 interferes with the cabin 12, the arrangement of the ultrasonic sensor that issues a command signal to make an emergency stop is set. Is shown.

On the front upper frame 12b of the cabin 12, front upper ultrasonic sensors 7.5 are arranged on the left and right, and the front upper ultrasonic sensors 7.5 detect that the bucket 1 approaches above the front of the cabin 12. It is configured to

A lower front ultrasonic sensor 13 is disposed at the right end of the cabin 12 in the traveling direction. The front lower ultrasonic sensor 13 is configured to detect the tip of the bucket 1 rising from below the cabin 12.

As described above, since the boom 6, the swing frame 22, and the arm 4 are not provided in the front portion of the cabin 12, and only the bucket 1 enters the dangerous area in this portion, the front upper ultrasonic sensors 7.5 are provided. And the lower front ultrasonic sensor 13 can be sensed in a state where the bucket 1 approaches a slightly distant position.

On the other hand, the side surface of the cabin 12 moves not only the bucket 1 but also the boom 6 and the arm 4.
Since the movement of the object is detected, it is configured to detect the movement by another sensor.

FIG. 6 is a front view showing the position of a touch sensor provided on the right side of the cabin 12, and FIG. 7 is a side view of the same.

The front touch sensor 19 is arranged along the front side frame 12a, and the upper touch sensor 18 is arranged on the upper side frame 12a.
It is arranged along d.

The front touch sensor 19 forms a side gap t1 between the front side frame 12a and the front side frame 12a.
A front gap t2 is formed between the front face a and the front face a. An upper gap t3 is formed between the upper surface touch sensor 61 and the front side frame 12a.

By providing the side gap t1, the front gap t2, and the upper gap t3 in this manner, even when the stop signal is output immediately after the bucket 1 touches the touch sensor, when the bucket 1 is further moved by the inertial force, the bucket 1 absorbs the gap. It is possible.

FIG. 8 is a rear sectional view of a mounting portion of the arm rotation angle detector 15, and FIG. 9 is a side view of the same.

The arm rotation angle detector 15, the swing frame rotation angle detector 16 and the boom rotation angle detector 17 are each constituted by a potentiometer, and the arm 4 and the swing frame
The rotation positions of the boom 6 and the boom 6 are detected and input to the controller CPU. However, when the potentiometer is mounted, it is mounted in a state where the axis of the pivot shaft 51 and the axis of the potentiometer shaft 15a are perfectly matched. Is difficult.

If the potentiometer is mounted in a state where the axes of the potentiometer shaft 15a and the pivot shaft 51 do not match,
Since the strength is higher on the side of the pivot shaft 51, the potentiometer shaft 15a is forcibly bent.

The present invention is configured such that in such a case, the arm rotation angle detector 15 is not destroyed even if the axes do not coincide.

That is, the arm 4 is pivotally supported by the pivot shaft 51, and the detector mounting body 50 is fixed to the side surface of the arm 4 by the mounting bolt 56.

A long hole 57 is opened in the flange portion of the detector mounting body 50, so that the position of the detector mounting body 50 can be adjusted.

The mounting bracket 55 protrudes inside the detector mounting body 50, and the arm rotation angle detector 15 is fixed. An arm 53 having an elongated hole 58 protrudes from a part of the potentiometer shaft 15a of the arm rotation angle detector 15, and the pivot shaft 51 is inserted into the elongated hole 58.
The side pin 54 is fitted. The pin 54 is an arm
The arm 52 is fixed to the end face of the pivot 51.

A seal 60 is provided inside the detector mounting body 50 to prevent raindrops from entering.

FIG. 10 is a block diagram of the safety mechanism of the backhoe according to the present invention, and FIG. 11 is a hydraulic circuit diagram of the safety mechanism of the backhoe.

As disclosed in FIG. 10, the emergency stop sensors include front upper ultrasonic sensors 7, 5, 13 and upper touch sensor 18, front touch sensor 19, upper surface touch sensor.
61 is provided around the cabin 12, and when the bucket 1 approaches this portion due to an erroneous operation, the movement of the bucket 1 is emergency stopped.

Further, the arm rotation angle detector 15, the swing frame rotation angle detector 16, the boom rotation angle detector 17, and the boom operation lever 9a, the arm operation lever 9b, and the swing operation pedal 29 are provided as described above. Potentiometer 62, 63, 64
Is calculated, and when the bucket 1 approaches the dangerous area line a, the swing actuator 3 is automatically operated to swing the bucket 1 to the position 1 '.

The signals from the potentiometer and the emergency stop sensor are transmitting signals to the five solenoid valves via the controller CPU.

The five solenoid valves include an electromagnetic safety valve 20, a swing automatic control solenoid valve 21, a swing stop solenoid valve 24, and a boom stop solenoid valve.
25 and an arm stop solenoid valve 26.

The swing automatic control solenoid valve 21 and the swing stop solenoid valve 24
The swing manual operation valve 30 and the swing actuator 3
The boom stop solenoid valve 25 is disposed between the boom manual operation valve 31 and the boom actuator 38, and the arm stop solenoid valve 26 is mounted on the arm manual operation valve 32.
And the arm actuator 39.

The signals from the potentiometers 15, 16, 17, 62, 63, 64 cause the solenoid valves 24, 25, 26 to be operated as required when they come to the danger zone line a or b as required.

That is, when the ultrasonic sensor and the bucket come to a from the front, the solenoids of the boom stop solenoid valve 25 and the arm stop solenoid valve 26 are turned off, and the solenoid valve is closed by the biasing spring provided on the opposite side. Is operated.

When the bucket comes to b from the right side, the swing stop solenoid valve 24 is operated in the same manner as described above to forcibly stop the bucket from approaching the cab.

In addition, the swing automatic control solenoid valve 21 automatically switches the bucket 1 to 1 'when the bucket 1 approaches the danger area line a by a signal from each of the potentiometers 15, 16, 17, 62, 63, 64 described above. Is operated to the position of.

In the present invention, in addition to these solenoid valves, as a double safety circuit, an abnormality occurs in the control circuit of the controller CPU, the forcible stop becomes impossible, the bucket comes closer, and the emergency stop sensor operates. Or when the power is turned off, the pilot pressure is supplied to operate the swing emergency stop solenoid valve 24, the boom emergency stop solenoid valve 25, the arm emergency stop solenoid valve 26, and the swing automatic control valve 21. The electromagnetic safety valve 20 for setting the pressure of the hydraulic circuit to zero is provided.

With this, the swing stop solenoid valve 24 and the boom stop solenoid valve
When the solenoid valve 25 and the arm stop solenoid valve 26 operate abnormally, the pilot pressure is released by the electromagnetic safety valve 20, so that each solenoid valve is forcibly closed and the boom 6, the arm 4, and the swing frame 22 are turned. The movement stops.

In FIG. 11, 35 is a bucket manual operation valve, 28 is a frame turning operation valve, 27 is a dumping plate operation valve, 23 and 34 are traveling operation valves, 41 is a speed change operation valve, 40 is a rotation motor device, and 65L and 65R are It is a traveling hydraulic motor.

(F) Effects of the Invention The present invention is configured as described above, and has the following effects.

A switching valve is provided between the manual control valve and the actuator to detect and calculate the intrusion of the bucket into the set dangerous area, close the switching valve, and detect the emergency detector. The pilot pressure supply to the switching valve is released based on the above, and an electromagnetic safety valve that closes the switching valve is provided.
In addition to closing the hydraulic circuit with the swing emergency stop solenoid valve 24, boom emergency stop solenoid valve 25, and arm emergency stop solenoid valve 26,
Since the pilot pressure that is supplied to operate each solenoid valve by the solenoid valve 20 is set to 0, the hydraulic circuit can be closed twice, and the swing emergency stop solenoid valve 24 and the boom emergency stop solenoid valve can be closed. Even when an abnormal operation occurs in the valve 25 or the arm emergency stop electromagnetic valve 26, the electromagnetic safety valve 20 can cover the abnormal operation and close the hydraulic circuit.

Since the ultrasonic sensor constituting the emergency detector is arranged in front of the driver's seat and the touch sensor constituting the emergency detector is arranged on the side of the driver's seat,
The ultrasonic sensor and the touch sensor do not overlap with each other, so that the cost can be prevented from increasing, and the dangerous area in front can be detected at a remote position by the ultrasonic sensors 7, 5 at the front. In the dangerous area, the boom 6 and the arm 4 can be arranged close to the cabin 12 by the touch sensor, so that the turning radius can be reduced.

A rotation angle detector for detecting a rotation position of a boom, a swing frame, or an arm is provided as a pivot shaft,
A pin which is loosely fitted to the pivot shaft and is interposed between the detector mounting body fixed to the pivot side and a pin away from the pivot shaft axis is also used as a pivot center of the pivot angle detector. Since the long hole provided in the long arm protruding from the position is fitted and engaged, even when the axis of the pivot 51 and the potentiometer do not match,
The eccentricity can be absorbed by the part 54.

This eliminates the need for potentiometer assembly accuracy and eliminates the need for alignment and adjustment.

[Brief description of the drawings]

1 is a side view of a small swivel type backhoe, FIG. 2 is a plan view of the same, FIG. 3 is a side view of the cabin 12, FIG. 4 is a plan view of the same, FIG. 5 is a front view of the same, FIG. FIG. 7 is a side view showing the position of the touch sensor provided on the right side surface of the cabin 12, FIG. 8 is a rear sectional view of a mounting portion of the arm rotation angle detector 15, and FIG. FIG. 10 is a block diagram of a safety mechanism of the backhoe according to the present invention, and FIG. 11 is a hydraulic circuit diagram of the safety mechanism of the backhoe. 1 ... bucket 4 ... arm 6 ... boom 12 ... cabin 15 ... arm rotation angle detector 16 ... swing frame rotation angle detector 17 ... boom rotation angle detector 18 ... upper touch sensor 19 Front contact sensor 20 Electromagnetic safety valve 21 Automatic swing control solenoid valve 22 Swing frame 24 Swing emergency stop solenoid valve 25 Boom emergency stop solenoid valve 26 Arm emergency stop solenoid valve

Continuing from the front page (72) Inventor Tetsuhiro Ohashi 428 Enami, Onami, Okayama Pref.Seirei Industry Co., Ltd. (72) Inventor Hideo Shimazoe 428 Enami, Okayama Pref. Literature Jpn. Showa 61-32255 (JP, U)

Claims (3)

(57) [Claims] A switching valve is provided between a manual control valve and an actuator to detect intrusion of a bucket into a set danger zone.
Compute and close the switching valve, and release the pilot pressure supply to the switching valve based on the detection result of the emergency detector,
A safety mechanism for a backhoe, comprising an electromagnetic safety valve for closing a switching valve. 2. The backhoe according to claim 1, wherein an ultrasonic sensor constituting the emergency detector is arranged in front of the driver's seat, and a touch sensor constituting the emergency detector is arranged on the side of the driver's seat. Safety mechanism. 3. A pivot angle detector for detecting a pivot position of a boom, a swing frame or an arm, comprising: a pivot shaft; and a detector mounting body loosely fitted to the pivot shaft and fixed to the pivot side. A pin located at a position distant from the axis of the pivot shaft is fitted and engaged with an elongated hole provided in an arm protruding from the rotation center position of the rotation angle detector. Backhoe safety mechanism.