JPH08218415A - Operator cab interference prevention device for hydraulic shovel and hydraulic shovel - Google Patents

Abstract

PURPOSE: To stop a bucket of a work machine more securely even when a solenoid valve for stop of a hydraulic system does not operate normally. CONSTITUTION: When a bucket 15 invades a stop indication position 42 set around an operator cab of a hydraulic shovel, an obstacle such as trash in hydraulic oil is caught in a spool of a solenoid valve for stop and the movement of the hydraulic shovel becomes dull even if a stop signal is output to the solenoid valve for stop from a controller. Therefore, an engine stop indication position 43 is set more on the operator cab side than the stop indication position 42 and the work is continued while abnormality condition is left as it is, and when the bucket 15 invades this position 43, an engine stop signal is output to a stop solenoid 17 for stopping an engine from the controller to stop the engine itself in emergency. Consequently, a pump which is a hydraulic oil source of each hydraulic actuator 22, 23, 24 stops simultaneously when the engine 16 stops and hydraulic oil does not flow into each hydraulic actuator 22, 23, 24 and stops so that interference between the bucket and operator cab is prevented securely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driver's cab interference preventing device and a hydraulic excavator for a hydraulic excavator of a small turning type or the like for preventing a working machine from interfering with a driver's cab.

[0002]

2. Description of the Related Art Conventionally, a small swing type hydraulic excavator has been developed with an increase in excavation work in a narrow place. A conventional example of this small turning hydraulic excavator will be described with reference to FIGS. 4 (a), 4 (b) and 5. FIG.

4 (a) and 4 (b) are a side view illustrating a conventional small turning hydraulic excavator and a plan view showing the left and right offset mechanisms of the bucket. First, FIG.
The configuration and operation of this small swing hydraulic excavator will be described. This hydraulic excavator consists of a cab 1, an upper revolving structure 6,
It is composed of the lower traveling body 7 and the working machine 10. Work machine 1
Reference numeral 0 includes a first boom 11, a second boom 12, a stay cylinder 13, an arm 14, and a bucket 15. With this configuration, as shown in FIG. 4A, the bucket 15 is attached to the first boom 11 located on the lateral side of the cab 1 on the upper swing body 6.
By moving the arm 14 in the lateral direction, the swing radius of the swing structure 6 is made as small as possible. The hydraulic excavator shown in FIG.
6, a stop solenoid 17 for stopping the engine 16, hydraulic actuators 22, 23, 24,
25 and angle sensors 31, 32 and 33 are provided. Further, the bucket 15 is connected to the arm 14 by a pin 50, and rotates about the pin 50 as a fulcrum along a bucket toe radius locus 51 shown in FIG. 4A.

In FIG. 4B, the central solid line shows the case where the bucket 15 exists at the neutral position, and the offset mechanism 10 with respect to the neutral position of the bucket 15 is shown.
If 0 is moved to the right, the bucket 15 moves in the direction A to the right two-dot chain line position, and similarly, the offset mechanism 1
If 00 is moved to the left, the bucket 15 moves in the B direction and moves to the left two-dot chain line position. Thus, by operating the offset mechanism 100, the position of the bucket 15 moves in parallel with the first boom 11 in the left-right direction in an arc shape,
The desired work can be performed.

However, there arises a problem of interference between the cab 1 and the bucket 15 of the working machine 10. This is because, when the bucket 15 is moved in the leftward B direction in FIG. 4B, for example, the spatial arrangement between the cab 1 and the bucket 10 in FIG. It happens.
In order to solve the problem that the working machine 10 interferes with the cab 1, the small swing hydraulic excavator is provided with a cab interference prevention device. Next, this driver's cab interference prevention device will be described with reference to FIGS. 4 (a), (b) and FIG.

FIG. 5 is a hydraulic system configuration diagram of a driver's cab interference prevention device for the small turning hydraulic excavator of FIGS. 4 (a) and 4 (b). In FIG. 5, the first boom 1 shown in FIG.
Based on the detection results of the angle sensors 31, 32, and 33 for detecting the rotation angle of 1, the rotation angle of the arm 14, and the offset operating angle, the controller 21 determines the bucket tip radius locus 51 of FIG. 4A. When the hydraulic pressure actuators 22 and 22 come into contact with the stop instruction position set around the cab 1,
Pilot valves 2, 3 for operating 23, 24,
4 outputs a stop signal 62 to a stop solenoid valve 60 provided on a pilot line between the control valve 61 and the control valve 61, and controls a spool for switching the flow of pressure oil in the stop solenoid valve 60 by moving the spool. By causing the signal pressure oil flowing to the valve 61 to flow to the oil tank 90, the spool of the control valve 61 is set to the neutral position and each hydraulic actuator 22, 2 is moved.
3, 24 are stopped. However, if the spool of the stopping solenoid valve 60 is caught by dust in the pressure oil or the like, the movement of the spool becomes sluggish.
If left as it is, the bucket 1 will be at the stop instruction position.
5 enters and the stop signal 6 is sent to the stop solenoid valve 60.
Even if 2 is output, the movement of the spool becomes sluggish, the pilot signal pressure oil may not be blocked, and the bucket 15 and the cab 1 may interfere. For this reason, when the bucket 15 enters the stop instruction position, measures such as alerting the operator with an alarm such as an alarm have been taken.

A related device as a conventional driver's cab interference preventing device for a hydraulic excavator of this type is disclosed in Japanese Unexamined Patent Publication No. HEI 2 (1993) -2000.
Those described in JP-A No. 204537 and JP-A No. 5-252628 can be mentioned.

[0008]

SUMMARY OF THE INVENTION In the above-mentioned prior art, the spool in the solenoid valve of the hydraulic system for stopping the front of the working machine of the hydraulic excavator becomes stuck due to dust in the pressurized oil and slows down the movement. If an abnormality is felt and if this abnormality is left unattended, and if the operator ignores warnings and continues to work, the spool motion will be slow and the work machine will not stop even if a stop signal for the driver's cab interference prevention device is output to the solenoid valve. However, there was a problem that the bucket and the driver's cab interfered with each other.

A first object of the present invention is to solve the above-mentioned problems of the prior art so that the bucket of the working machine can be more surely operated even when the solenoid valve for stopping the hydraulic system is not operating normally. A second object is to provide a driver's cab interference prevention device for a hydraulic excavator and a hydraulic excavator that can be stopped and can return to a posture in which the machine can be quickly repaired even after the bucket of the working machine is stopped. It is in.

[0010]

In order to achieve the above object, a cab interference prevention device for a hydraulic excavator according to the present invention comprises:
When the detecting means detects the position of the bucket of the working machine and the detecting means detects that the bucket has entered the stop instruction position set near the driver's cab, the working hydraulic oil actuator of the working machine is forcibly stopped. When the detecting means detects that the stopping means and the stopping means do not operate normally and the bucket has entered the engine stop instruction position set closer to the driver's cab than the stop instruction position, the hydraulic actuator is activated. It comprises an engine emergency stop means for making an emergency stop of an engine directly connected to a pump for sending hydraulic pressure to stop the hydraulic pressure sending of the pump.

Further, an operating pilot valve provided in the operator's cab, a detecting means for detecting a boom rotation angle, an arm rotation angle and an offset operation angle of the working machine to detect the position of the bucket, the boom and the arm. , An actuator for offset operation, the solenoid valve for stopping the actuator provided on the output side of the pilot valve, and a solenoid valve for stopping provided between the solenoid valve for stopping and the actuator, and a hydraulic pressure is directly supplied from a hydraulic source directly connected to the engine and stopped. The control valve that switches the direction by operating pressure oil from the pilot valve via the solenoid valve for operation, and the pilot valve from the pilot valve when the detection means detects that the bucket has entered the stop instruction position set around the cab. Stop operating pressure oil to prevent it from going to the control valve. A controller for controlling the id valve, and when detecting that the bucket has entered the engine stop instruction position set at a position closer to the driver's cab around the operator's cab by the detection means, The controller is configured to perform an emergency engine stop and stop the pressure oil delivery from the hydraulic pressure source to the control valve.

Further, in the driver's cab interference prevention device for a hydraulic excavator having the above structure, a release switch for disconnecting the controller from the hydraulic system when the controller is in an emergency stop state by the controller is provided, and the operator uses the release switch. When the engine is restarted after disconnecting the controller, the bucket can be moved in a direction to escape from the engine stop instruction position.

In the operator cab interference prevention device for a hydraulic excavator having the above structure, the hydraulic excavator is a small swing type hydraulic excavator, and the arm and the bucket are movable in parallel to the boom in the left-right direction. It may be.

Further, the hydraulic excavator of the present invention is a hydraulic excavator comprising a lower traveling body, an upper revolving superstructure, and a driver's cab and a working machine arranged side by side on the revolving superstructure. It is equipped with one of the room interference prevention devices.

[0015]

The operation cab interference preventing device and the hydraulic excavator for the hydraulic excavator output a stop signal from the controller to the stop solenoid valve when the bucket enters the stop instruction position set around the cab of the hydraulic excavator. The bucket is stopped by shutting off the pilot pressure oil. However, even if the above stop solenoid valve receives a stop signal, the spool in the stop solenoid valve may be caught by an obstacle such as dust in the pressure oil and become sluggish in movement. In this case, when the bucket enters the engine stop instruction position set on the driver's cab side from the stop instruction position, the controller outputs an engine stop signal to stop the engine itself, causing each hydraulic actuator to operate. The pump, which is the hydraulic pressure source that supplies the pressure oil to the control valve that supplies the pressure oil, is directly connected to the engine. Since the pressure oil stops without flowing, interference between the bucket and the operator's cab can be more reliably prevented.

Also, after the engine is stopped, the operator operates a release switch that can disconnect the controller from the hydraulic system, so that the bucket of the working machine can be moved regardless of the calculation result of the controller. As a result, the operator can quickly move the bucket in the direction opposite to the interference direction by an operation, and it is possible to receive necessary repairs.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a side view of a small turning hydraulic excavator showing an embodiment of a driver's cab interference prevention device for a hydraulic excavator and a hydraulic excavator of the present invention. In FIG. 1, the hydraulic excavator is composed of a driver's cab 1, an upper swing body 6, a lower traveling body 7, and a working machine 10. The working machine 10 includes a first boom 11, a second boom 12, a stay cylinder 13, and an arm. 1
4 and a bucket 15. The first boom 11 of the working machine 10 is arranged laterally laterally of the operator cab 1 on the upper swing body 6. The hydraulic excavator includes hydraulic actuators 22, 23, 24, a pilot valve 2 for operation,
3, 4, engine 16, stop solenoid 17 for stopping engine, booms 11, 12, arms 14, offset, hydraulic actuators 22, 23, 24, 25 for operating bucket 15, first boom 11 and body A boom angle sensor 31 for detecting a relative angle between the second boom 12 and the arm 14, an arm angle sensor 32 for detecting a relative angle between the second boom 12 and the arm 14, an offset sensor 33 for detecting a relative angle between the first boom 11 and the second boom 12, and an arm pin. 50 and a release switch 70 for disconnecting the controller 21 from the hydraulic system are provided.

Further, in FIG. 1, an interference region 41, a stop instruction position 42 indicating a position where a stop signal is output from the controller 21 to the stop solenoid valve 60, and an engine stop for stopping the engine from the controller to the stop solenoid 17 are shown. The engine stop instruction position 43 that outputs the signal 63, the bucket toe locus 5 and the bucket toe radius locus 51 when the bucket 15 is closest to the cab 1 are shown. The coordinate system of the hydraulic excavator in FIG. 1 is defined as the front-rear direction, the vertical direction, and the left-right direction with respect to the machine as X, Y, and Z axes.

FIG. 2 is a hydraulic system configuration diagram of the operator cab interference prevention device for the small turning hydraulic excavator of FIG. In FIG. 2, the boom, arm, and offset angle of the working machine 10 are defined under a coordinate system defined by the hydraulic excavator of FIG. 1 in which the X, Y, and Z axes are the longitudinal, vertical, and lateral directions of the machine. Based on the detected angle results of the angle sensors 31, 32, 33, the controller 21 calculates the coordinates of the arm pin 50 of the working machine, and the calculated value is the coordinate value of the bucket tip radius circle from the center of the arm pin 50. By adding, the coordinate value of the bucket toe radius locus 51 is obtained. Therefore, when the bucket toe radius locus 51 comes into contact with the stop instruction position 42 set around the outside of the cab 1, the controller 21 outputs a stop signal 62 to the stop solenoid valve 60 to stop the working machine 10. Thus, the bucket 15 is controlled so as not to further enter the interference area 41 from the stop instruction position 42.

Now, the stop solenoid valve 6 is used.
It is conceivable that dust or the like in the pressure oil is caught in the spool for switching the flow of the pressure oil existing in 0, and the stop solenoid valve 60 cannot operate normally. In this situation, the stop solenoid valve 6
Continue the work while leaving the 0 abnormality left, and
The bucket toe radius locus 51
May enter the stop instruction position 42 and the stop signal 62 is output from the controller 21 to the stop solenoid valve 60, the pilot pressure oil from the pilot valves 2, 3 and 4 may not be cut off, so that the bucket 15 may not stop. .

Therefore, in this embodiment, the stop instruction position 4 shown in FIG.
The engine stop instruction position 43 is set closer to the driver's cab 1 than 2 and when the bucket tip radius locus 51 of the bucket 5 enters the engine stop instruction position 43, the engine 16 is stopped when the conventional work is interrupted and ended. By outputting an engine stop signal 63 from the controller 21 to the stop solenoid 17 for stopping, the fuel cut lever is moved through a rod (not shown) coming out of the stop solenoid 17 to cut the fuel itself supplied to the engine 16. By doing so, the engine 16 is stopped urgently. Then, the engine 16 stops, and at the same time, the main pump 19 of the hydraulic system directly connected to the engine 16
Since the control valve 61 is not supplied with working oil for moving the hydraulic actuators 22, 23, 24, the working machine 10 is stopped, that is, the bucket 1
5 also stops, so that interference with the cab 1 can be prevented more reliably.

Although the purpose of the interference prevention function as the driver's cab interference prevention device is achieved by the above, if this interference avoidance state is maintained, the hydraulic excavator remains in this position and posture. I have trouble. Therefore, when the engine 16 is started again with the engine stopped, the controller 21 at this time determines that the bucket tip radius trace 51 of the bucket 15 exceeds the engine stop instruction position 43, and therefore the engine is restarted. Since 16 is stopped, the operator cannot move the machine to a safe place or a place where it can be repaired. Therefore, to prevent it,
A release switch 70 for disconnecting the controller 21 from the hydraulic system is provided, and an operator operates the release switch 70 to prevent a signal from being output from the controller 21 to the stop solenoid valve 60. Valves 2, 3,
4 and the control valve 61 are directly connected. Therefore, it becomes a hydraulic circuit that can move the working machine 10 regardless of the calculation result of the controller 21, and the operator can move the machine body, whereupon the machine body can be moved to a safe place or a place where it can be repaired.

FIG. 3 is an operation flow chart of the hydraulic system of FIG. In FIG. 3, 80 shows a flow when the stop solenoid valve 60 of FIG. 2 operates normally, and 81 shows a flow when the stop solenoid valve 60 does not operate normally. In FIG. 3, when the operator starts the hydraulic system of FIG. 2, in step 301, the controller 21 causes the boom, arm and offset angle sensor 3 to move.
Input the detection values of 1, 32, and 33. Step 302
Then, the center position of the arm pin 51 of FIG. 1 is calculated based on the input value of each angle sensor. In step 303, the bucket tip radius locus 5 of the value obtained by adding the bucket tip radius to the calculated value
It is determined whether 1 has entered the stop instruction position 42. If there is no intrusion here, steps 301 to 303 are repeated. Further, when it enters, the stop signal 62 is output to the stop solenoid valve 60 to drive the stop solenoid valve 60 in step 304.

Next, at step 307, it is determined whether or not the bucket tip radius has entered the engine stop instruction position 43 closer to the cab 1 than the stop instruction position 42. If it is determined that the vehicle has entered, then in step 308, the engine emergency stop signal 6 is sent to the stop solenoid 17 for stopping the engine.
3 is output to drive the stop solenoid 17. Then, the fuel cut lever is moved through a rod (not shown) coming out of the stop solenoid 17 to cut the fuel supplied to the engine 16 to stop the engine 16, and at the same time, directly connect to the engine 16. Since the main pump 19 that is present is also stopped, hydraulic oil for moving the hydraulic actuators 22, 23, 24 is not supplied to the control valve 61, so that the working machine 10 is stopped, that is, the bucket 15 is also stopped, so that the interference region 41 may enter. Therefore, the interference with the cab 1 is more reliably avoided. Next, when the operator restarts the engine 16 as it is, the controller 21 causes the bucket tip radius trajectory 5
Since it is judged that 1 exceeds the engine stop instruction position 43 and the engine 16 is stopped again, step 31
At 0, it is judged whether the operator pushes the release switch 70 for disconnecting the controller 21 from the hydraulic system. If not, the engine is stopped again at step 308. However, if the release switch 70 is pressed, the drive of the stop solenoid valve 60 is released in step 400, and the operator can escape the bucket 15 from the periphery of the cab 1 and move the machine to a safe place for immediate repair. . In the present embodiment, step 401,
When the bucket 15 is retracted from the engine stop instruction position 43 by 402 and 403, the process returns to step 301 and the normal operation is permitted.

Although the working machine has an offset mechanism in the small turning hydraulic excavator in the above embodiment, the present invention is not limited to this, and the working machine may interfere with the cab. It is also applicable to hydraulic machines such as hydraulic excavators.

[0026]

According to the present invention, when the bucket of the hydraulic excavator enters the stop instruction position set around the operator's cab, the spool in the solenoid valve for stopping for forcibly stopping the hydraulic actuator is the dust in the oil. When the bucket enters the engine stop instruction position set on the driver's cab side from the stop instruction position, the spool moves slowly and the spool moves slowly. By making an emergency stop of the engine itself, it is possible to stop the hydraulic pump that is directly connected to the engine, which is the source of the hydraulic oil that operates the hydraulic actuator, so that the interference between the bucket and the cab is more certain than before. It is possible to prevent it and there is an effect that safety can be improved. In addition, since the hydraulic system uses the existing components as they are, the cost is not increased and there is an economic effect. Further, since the release switch for disconnecting the controller from the hydraulic system after the engine is stopped is provided, it is possible to quickly move the aircraft to a safe place or a place where repair can be performed by an operator's operation.

[Brief description of drawings]

FIG. 1 is a side view of a hydraulic excavator showing an embodiment of the present invention.

2 is a hydraulic system configuration diagram of FIG. 1. FIG.

3 is an operation flow diagram of the hydraulic system of FIG.

4A and 4B are a side view illustrating a conventional hydraulic excavator and a plan view of an offset mechanism thereof.

5 is a hydraulic system configuration diagram of FIG. 4.

[Explanation of symbols]

 1 Operator's cab 2, 3, 4 Pilot valve 5 Bucket toe locus 6 Upper revolving structure 7 Lower traveling structure 10 Working machine 11 First boom 12 Second boom 13 Stay cylinder 14 Arm 15 Bucket 16 Engine 17 Stop solenoid 19 Main pump 21 Controller 22, 23, 24, 25 Hydraulic actuator 31 Boom angle sensor 32 Arm angle sensor 33 Offset angle sensor 41 Interference area 42 Stop instruction position 43 Engine stop instruction position 50 Arm pin 51 Bucket tip radius locus 60 Stop solenoid valve 61 Control valve 62 Stop signal 63 Engine stop signal 70 Release switch 100 Offset mechanism

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Nishimura 650 Jinrachicho, Tsuchiura City, Ibaraki Prefecture Tsuchiura Factory, Hitachi Construction Machinery Co., Ltd. (72) Inventor Shudo Yamada 1-1 1-1 Fujikoshimotocho, Toyama City, Toyama Fuji Kochi Co., Ltd. (72) Takashi Matsuda 1-1-1 Fujikoshi Honmachi, Toyama City, Toyama Prefecture Fuji Kochi Co., Ltd. (72) 1-1 1-1 Fujikoshi Honcho, Toyama City, Toyama Prefecture Fujikoshi Co., Ltd.

Claims (6)

[Claims] 1. A detecting means for detecting the position of a bucket of a working machine, and a hydraulic actuator for operating the working machine when the detecting means detects that the bucket has entered a stop instruction position set near a driver's cab. When the detecting means detects that the bucket has entered the engine stop instruction position set closer to the driver's cab than the stop instruction position, the stop means for forcibly stopping the A driver's cab interference prevention device for a hydraulic excavator, comprising engine emergency stop means for emergency stop of an engine directly connected to a pump for sending pressure oil to the hydraulic actuator to stop hydraulic output of the pump. 2. An operating pilot valve provided in a cab, a detection means for detecting a bucket rotation position by detecting a boom rotation angle, an arm rotation angle and an offset operation angle of a working machine, a boom and an arm. , An offset actuating actuator, the above-mentioned actuator stopping solenoid valve provided on the output side of the pilot valve, and provided between the stopping solenoid valve and the actuator, and hydraulic pressure is supplied from a hydraulic source directly connected to the engine,
In addition, when the control valve that changes the direction by operating pressure oil from the pilot valve via the solenoid valve for stopping and the detection means that the bucket has entered the stop instruction position set around the cab, the pilot A controller for controlling the stop solenoid valve so that the operating pressure oil from the valve does not go to the control valve, and the bucket is moved closer to the cab around the cab than the stop instruction position by the detection means. When the entry into the engine stop instruction position set to the position is detected, the controller performs an emergency engine stop and stops the pressure oil delivery from the hydraulic source to the control valve, and the driver's cab interference for the hydraulic excavator Prevention device. 3. When an engine is stopped by the controller in an emergency, a release switch for disconnecting the controller from the hydraulic system is provided, and when the operator uses the release switch to restart the engine after disconnecting the controller. 3. The driver's cab interference prevention device for a hydraulic excavator according to claim 2, wherein the bucket can be moved in a direction to escape from the engine stop instruction position. 4. The operator cab interference prevention device for a hydraulic excavator according to claim 1, wherein the hydraulic excavator is a small swing type hydraulic excavator. 5. The operator cab interference prevention device for a hydraulic excavator according to claim 4, wherein the arm and the bucket are movable in parallel with the boom in the left-right direction. 6. The hydraulic excavator according to claim 1, wherein the hydraulic excavator comprises a lower traveling body, an upper revolving superstructure, and a driver's cab and a working machine which are arranged side by side on the revolving superstructure. Hydraulic excavator equipped with a driver's cab interference prevention device.