JPH086836Y2 - Lateral posture stabilizer for hydraulic excavator - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a vehicle body fall prevention device when a hydraulic excavator is in a lateral position. To prevent the work machine from protruding outside the range, swing the upper swing body, push out the arm,
Also, the present invention relates to a lateral posture stabilizing device for a hydraulic excavator that automatically stops the bucket dump operation.

[Conventional technology]

Conventionally, when a hydraulic excavator is used for basic dismantling work, as shown in FIG.
In many cases, the work is performed in a so-called side posture in which the vehicle is turned by a certain angle, and depending on the work content, the weight of the working machine 23 (including the weight of luggage) has a great influence on the vehicle body balance, and Since there is a risk of falling, the allowable work range at the tip of the work machine is regulated. The operator feels the value of the work machine tilt angle meter attached to the work machine or the body balance with his / her body, and performs the work carefully so that the tip of the work machine does not protrude from the allowable work range.

[Problems to be solved by the device]

In the above-mentioned conventional technology, in a vehicle equipped with a tilt angle meter, the work efficiency decreases because the operator works while looking at the tilt angle meter during work, and the tilt angle meter is mounted because the operator made a mistake in operating the work machine lever. There was a case to fall. On the other hand, the method based on the vehicle body balance has a problem in safety because it relies on the experience of the operator.
The present invention focuses on the above-mentioned problems, and when working in a lateral position, when an overload is detected by the hydraulic pressure on the bottom side of the boom cylinder, the swing operation valve, the pushing side of the arm operation valve, and the dump side of the bucket operation valve are detected. It is an object of the present invention to provide a safety device for preventing a vehicle body from tipping over by cutting off an operation signal to the vehicle so that the tip of the working machine does not project out of the allowable working range even if an operator makes an erroneous operation.

[Means for solving the problem]

In order to achieve the above object, a lateral posture stabilizing device in a hydraulic excavator according to the present invention comprises: (1) an upper swing body which is swingably supported by a lower traveling body and to which a working machine is attached; Each operation valve that supplies the pressure oil discharged from the hydraulic pump to the boom cylinder, arm cylinder, bucket cylinder, swing motor, etc. of the working machine, and each control pressure valve that outputs a pilot signal for switching the direction of each operation valve. A hydraulic excavator equipped with, a changeover switch 14 for selecting to excavate by a working machine at a position where an upper swing body is swung to the side of the vehicle body, and a hydraulic pressure for detecting the hydraulic pressure of the boom cylinder 15. Detecting means 16, a signal from the changeover switch 14 that is selected for lateral excavation of the vehicle body, and from the hydraulic pressure detecting means 16 when the hydraulic pressure acting on the boom cylinder 15 exceeds a set pressure. Solenoid valve 10a for shutting off pilot pressure between the control pressure valves 6a, 6b, 7a, 8a and the operation valves 2, 3, 4 in order to regulate the movements of the arm cylinder, bucket cylinder and swing motor in response to the signal. , 10b, 10c, 10d are provided.

(2) Further, in the above structure, a signal from the turning angle signal device 18 for detecting the turning angle of the upper revolving structure with respect to the lower traveling structure and the signal from the changeover switch 14 selected for lateral excavation of the vehicle body is received, and the upper revolving structure is also received. The arm cylinder 12 receives a signal from the hydraulic pressure detection means 16 when the turning angle of the vehicle is in a predetermined turning range position with respect to the undercarriage and the hydraulic pressure acting on the boom cylinder 15 is equal to or higher than a set pressure. , Solenoid valves 10a, 10b, 10c for shutting off pilot pressure between the control pressure valves 6a, 6b, 7a, 8a and the operation valves 2, 3, 4 for controlling the movements of the bucket cylinder 13 and the swing motor 11. It has a configuration provided with 10d.

[Action]

According to the above configuration, when the detection value of the hydraulic pressure detector exceeds the predetermined value when the hydraulic excavator is in the lateral posture, the swing operation valve, the push side of the arm operation valve, and the dump operation side of the bucket operation valve are moved to the dump side. By cutting the operation signal, even if the operation lever of each operation valve is operated, the swinging of the upper swing body, the pushing of the arm, and the dumping operation of the bucket are disabled, and the risk of the vehicle body overturning is prevented. You can Further, in the lateral posture stabilizing device in the hydraulic excavator, the swing angle of the upper swing body with respect to the lower traveling body is detected by a limit switch, and each operation valve of the working machine drive actuator is used as a control hydraulic control system. The proportional pressure valve controlled by the working machine lever, the left / right swing side of the swing operation valve, the push side of the arm operation valve, and the dump side control hydraulic cylinder of the bucket operation valve are connected via electromagnetic on-off valves, respectively. According to this configuration, when the detection value of the hydraulic pressure detector exceeds the predetermined value when the hydraulic excavator is in the lateral posture, the limit switch and the hydraulic pressure detector shut off the electromagnetic on-off valve to prevent Even if the work implement lever is operated, turning of the upper revolving structure in the left-right direction, pushing of the arm, and dump operation of the bucket are disabled. It is therefore possible to prevent the risk of the vehicle overturning.

〔Example〕

An embodiment of a lateral posture stabilizing device for a hydraulic excavator according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an electrohydraulic circuit diagram of a lateral posture stabilizing device in a hydraulic excavator according to an embodiment of the present invention, and FIG. 2 (a).
2B is a cross-sectional view of the swing circle portion showing the mounting relationship of the dog and the limit switch for detecting the turning angle, FIG.
FIG. 6 is a diagram showing a range in which a dog and a turning angle detection limit switch are in contact with each other. The hydraulic pump 1 shown in FIG. 1 is connected to each operation valve 2-5. The turning operation valve 2 is connected to a turning motor 11. The arm operation valve 3 is connected to the arm cylinder 12. The bucket operation valve 4 is connected to the bucket cylinder 13. The boom operation valve 5 is connected to the boom cylinder 15. The control hydraulic pump 9 is connected to each control pressure valve 6a, 6b, 7a, 7b, 8a, 8b for converting the operation amount of each of the turning and working machine operating levers 6, 7, 8 into a hydraulic pressure. The control pressure valves 6a and 6b are connected to the turning operation lever 6. The control pressure valves 7a and 7b are connected to the arm operation lever 7. The control pressure valves 8a and 8b are connected to the bucket operating lever 8.

This control pressure valve 6a is an electromagnetic opening / closing valve from the pilot line 9a.
It is connected to the operation portion 2b of the turning operation valve 2 via 10a. Control pressure valve 6b is a solenoid valve from pilot line 9b
It is connected to the operation portion 2a of the turning operation valve 2 via 10b. These solenoid on-off valves 10a-10d are normally in the open position (a
Position).

As a result, when the turning lever 6 is operated to the left, the control pressure valve
The control pressure output from 6a is input to the operating portion 2b of the turning operation valve 2 through the position a of the electromagnetic opening / closing valve 10a, and the turning operation valve 2 is switched to the position b. Therefore, the discharge flow rate from the hydraulic pump 1 flows into the swing motor 11 through the position b of the swing operation valve 2 and rotates the swing motor 11 counterclockwise.

When the turning operation lever 6 is operated to the right, the control pressure output from the control pressure valve 6b is input to the operation portion 2a of the turning operation valve 2 through the position a of the electromagnetic opening / closing valve 10b, and the turning operation valve 2 is turned a. Switch to position. Therefore, the discharge flow rate from the hydraulic pump 1 flows into the swing motor 11 through the position a of the swing operation valve 2 and rotates the swing motor 11 clockwise.

Next, the control pressure valve 7a is connected to the operation portion 3b of the arm operation valve 3 from the pilot conduit 9c via the electromagnetic opening / closing valve 10c. The control pressure valve 7b is directly connected to the operation portion 3a of the arm operation valve 3 via the pilot conduit 9d.

When the arm operation lever 7 is operated to the push-out side, the control pressure output from the control pressure valve 7a is input to the operation portion 3b of the arm operation valve 3 through the position a of the electromagnetic opening / closing valve 10c,
The arm operation valve 3 is switched to the b position. Therefore, the discharge flow rate from the hydraulic pump 1 flows into the bottom chamber of the arm cylinder 12 through the position b of the arm operation valve 3 and drives the arm cylinder 12 to the pushing side. When the arm operating lever 7 is operated to the retracted side, the control pressure output from the control pressure valve 7b is input to the operating portion 3a of the arm operating valve 3 to switch the arm operating valve 3 to the a position. Therefore, the hydraulic pump 1
The discharge flow rate from the arm cylinder 12 passes through the position a of the arm operation valve 3 and flows into the head chamber of the arm cylinder 12.
Drive to the retracted side.

Further, the control pressure valve 8a is connected to the operating portion 4b of the bucket operating valve 4 from the pilot conduit 9e via the electromagnetic opening / closing valve 10d. The control pressure valve 8b is directly connected to the operating portion 4a of the bucket operating valve 4 via the pilot conduit 9f.

When the bucket operating lever 8 is operated to the push-out side, the control pressure output from the control pressure valve 8a is a of the electromagnetic opening / closing valve 10d.
It is input to the operating portion 4b of the bucket operating valve 4 through the position to switch the bucket operating valve 4 to the b position. Therefore, the discharge flow rate from the hydraulic pump 1 is b of the bucket control valve 4.
Flowing into the head chamber of the bucket cylinder 12 through the position,
The bucket cylinder 12 is driven to the push side. When the bucket operating lever 8 is operated to the retracted side, the control pressure output from the control pressure valve 8b is input to the operating portion 4a of the bucket operating valve 4 to switch the bucket operating valve 4 to the a position. Therefore, the discharge flow rate from the hydraulic pump 1 flows into the bottom chamber of the bucket cylinder 12 through the position a of the bucket operation valve 4, and drives the bucket cylinder 12 to the excavation side.

Next, the changeover switch 14 can select a release position and an operating position. The changeover switch 14 is connected to the electromagnetic on-off valves 10a to 10d via the electric circuit I in the release position. When the changeover switch 14 is in the release position and the electric circuit I is energized, the solenoid opening / closing valves 10a to 10d are opened (position a).
become. The changeover switch 14 is connected to the electromagnetic opening / closing valves 10a to 10d from the electric circuit II via the hydraulic switch 16 in the operating position. The hydraulic switch 16 is connected to the bottom chamber of the boom cylinders 15, 15. When the changeover switch 14 is in the operating position and the electric circuit II is energized, the solenoid opening / closing valves 10a to 10d are in the open position (position a). However, when the hydraulic pressure applied to the bottom chamber of the boom cylinders 15 and 15 exceeds the set pressure,
The hydraulic switch 16 switches from a-contact to b-contact and the electric circuit
The electromagnetic on-off valves 10a to 10d are not energized from II, and the electromagnetic on-off valves 10a to 10d are in the closed position (position b).

As a result, the control pressures from the control pressure valves 6a, 6b are shut off and the swing operation valve 2 is deactivated, and the hydraulic pump 1
The discharge flow rate from is not supplied to the swing motor 11, and the left-right rotation of the swing motor 11 is stopped.

Further, the control pressure from the control pressure valve 7a is shut off, the operation of the arm operation valve 3 to the position b is stopped, and the discharge flow rate from the hydraulic pump 1 is not supplied to the bottom side of the arm cylinder 12, so that the arm cylinder The driving of 12 to the extrusion side is stopped.

Further, the control pressure from the control pressure valve 8a is shut off, the operation of the bucket operation valve 4 to the b position is stopped, and the discharge flow rate from the hydraulic pump 1 is not supplied to the head side of the bucket cylinder 13, The driving of 13 to the extrusion side is stopped.

When the hydraulic pressure applied to the bottom chamber of the boom cylinders 15 and 15 exceeds the set pressure, the hydraulic switch 16 is switched from the a contact to the b contact, and the electric circuit IV is energized.
The red warning light 17 is turned on. In addition, 24 is a power supply. A limit switch 18 is connected to the electric circuit III, and the changeover switch 14 is set to the "operation" side,
When the upper swing body 21 is not swinging, the dog 19 on the swing circle is moved to the limit switch 18 as shown in FIG.
Is switched to the a contact, and the electric circuit III is energized, but when the upper swing body 21 swings with respect to the lower traveling body 22 and shifts to the side posture state, the dog 19 switches the limit switch 18 to the b contact state. By switching to the contact, the electric circuit V is energized and the yellow side working light 20 is turned on.

Next, the operation will be described. Since the work is performed with the upper revolving structure 21 swung to the side, the changeover switch switch
Set 14 to "Activated" position. When the upper revolving structure 21 is not revolving, use the dog 19 to push the limit switch 18
Since it is switched to the contact point, no current flows in the electric circuit V. Electric circuit II is hydraulic switch 16, solenoid on-off valve 10a
Since it is grounded through ~ 10d, it becomes energized,
The solenoid on-off valves 10a to 10d are excited, and the operation levers 6, 7, 8 and the operation valves 2, 3, 4 are connected, and the operation levers 6, 7, 8
When is operated, the control hydraulic pressure from the control hydraulic pump 9 can switch the operation valves 2, 3, 4 and operate the respective hydraulic actuators 11, 12, 13. When the upper swing body 21 is swung to move to the position in the side posture, the limit switch 18 is not affected by the dog 19, so that the electric circuit V becomes conductive and the yellow side work light 20 lights up. The operator can recognize that the upper swing body 21 is shifting to the side posture, which is a condition for the stability of the vehicle body. When work that tries to get the work implement out of the allowable work range occurs, even if the load on the tip of the work implement is the same, if the reach extends, the hydraulic pressure on the bottom side of the boom cylinder 15 increases to maintain this. Then, when the bottom hydraulic pressure of the boom cylinder 15 becomes equal to or higher than the set pressure, the hydraulic switch 16 becomes the b contact, and the solenoid opening / closing valve
When the current to 10a to 10d is cut off, the spool moves to the right by the spring, so the control oil pressure introduced via the control valve by the operation levers 6, 7, 8 is cut off, and the operation valve
The control oil pressures of 2, 3 and 4 are drained through the solenoid on-off valves 10a to 10d, and the operation valves 2, 3 and 4 are in a neutral state. Therefore, the hydraulic actuators 11, 12, 13 can be maintained in a stopped state to prevent the vehicle body from tipping over. At the same time, the electric circuit IV
Is turned on, the red warning light 17 is turned on, and the operator can know that the working machine is trying to be projected outside the allowable working range. In this way, when the working machine is automatically stopped, even if the operating levers 6, 7, 8 are moved, the inflow of the control hydraulic pressure is stopped by the electromagnetic on-off valves 10a to 10d, so the direction in which the vehicle body falls due to an erroneous operation There is no danger of operating. In addition, the pull-in side of the arm cylinder 12 where the solenoid on-off valves 10a to 10d are not mounted, the bucket cylinder 13
When the operation levers 6, 7, and 8 are moved to the excavation side, the control hydraulic pressure acts on the operation valves 3 and 4, so that the operation of pulling the working machine tip toward the vehicle body can be performed. When the upper revolving structure 21 is not in the position in the side position, the limit switch 18
Is connected to the b contact, the electromagnetic on-off valves 10a to 10d are excited by the electromagnetic circuit III, and the boom cylinder
Even if the hydraulic pressure on the bottom side of 15 reaches the set pressure and the hydraulic switch 16 is switched to the b contact, the red warning light 17 lights up,
Since the solenoid on-off valves 10a to 10d are continuously excited, the work is not stopped. That is, when the upper swing body 21 is in the front-rear position, the allowable work range for tipping of the vehicle body is wider than in the lateral posture, and even if the hydraulic pressure on the boom cylinder bottom side reaches the set value, there is a risk of tipping. This is because there is no When you do not work in the side posture, set the selector switch 14 to the “release” position and set the solenoid valves 10a to 10d.
Since the excitation of is done by the electric circuit I, normal work can be performed, and the hydraulic switch 16 and limit switch 1
Since no current flows to 8, the yellow side work light 20 and the red warning light 17 are not turned on.

[Effect of device]

As described above, according to the lateral posture stabilizing device for the hydraulic excavator according to the present invention, when the work is performed in the lateral posture, when the changeover switch is set to the operating position, there is a risk that the upper swing body will fall. If the tip of the work implement protrudes beyond the allowable work range where the vehicle is in a large lateral posture and the bottom hydraulic pressure of the boom cylinder exceeds the set value, there is a risk of the vehicle body falling over. Instead, the supply of pressure oil to the actuator is stopped, the operation of the working machine is blocked, and the vehicle body is prevented from tipping over, so that the safety is improved.

[Brief description of drawings]

1 to 3 are views showing a lateral posture stabilizing device in a hydraulic excavator according to an embodiment of the present invention, and FIG. 1 is an electrohydraulic circuit diagram of a lateral posture stabilizing device in a hydraulic excavator,
FIG. 2 (a) is a cross-sectional view of a swing circle portion showing a mounting relationship between a dog and a limit switch for detecting a turning angle,
FIG. 2 (b) is a diagram showing a range in which the dog and the turning angle detecting limit switch are in contact with each other, and FIG. 3 is a diagram showing an allowable work range in the side working posture. 1 …… hydraulic pump 2 …… swing control valve 3 …… arm control valve 4 …… bucket control valve 5 …… boom control valve 6 …… swing control lever 7 …… arm control lever 8 …… bucket control lever 9 …… Control hydraulic pump 10 …… solenoid valve 11 …… swing hydraulic motor 12 …… arm cylinder 13 …… bucket cylinder 14 …… changeover switch 15 …… boom cylinder 16 …… hydraulic switch 17 …… red warning light 18 …… limit Switch 19 …… Dog 20 …… Yellow side work light 21 …… Upper revolving structure 22 …… Lower traveling structure 23 …… Working machine 24 …… Power supply

Claims (2)

[Scope of utility model registration request] 1. A lower traveling body rotatably supported by the lower traveling body, and
The upper revolving structure to which the working machine is attached, each operation valve that supplies the pressure oil discharged from the hydraulic pump to the boom cylinder, arm cylinder, bucket cylinder, and revolving motor of the working machine, and the direction of each operation valve. In a hydraulic excavator equipped with each control pressure valve that outputs a pilot signal for switching between, a changeover switch (14) for selecting excavation by a working machine at a position where the upper swing body is swung to the side of the vehicle body.
And a hydraulic pressure detection means (16) for detecting the hydraulic pressure of the boom cylinder (15), and a signal from the changeover switch (14) for which the lateral excavation of the vehicle body is selected, and the boom cylinder (15). Control pressure valve (6a, 6b, 7a, 8a) for controlling the movement of the arm cylinder, bucket cylinder and swing motor in response to the signal from the hydraulic pressure detection means (16) when the hydraulic pressure to be set exceeds the set pressure. Solenoid valve (10a, 10b, 10) that shuts off pilot pressure between the control valve and the operating valve (2, 3, 4)
c, 10d) is provided, which is a lateral posture stabilizing device in a hydraulic excavator. 2. A turning angle signal device (18) for detecting a turning angle of an upper revolving structure with respect to a lower traveling structure and a signal from a changeover switch (14) selected for lateral excavation of a vehicle body, and the upper revolving structure. A signal from the hydraulic pressure detection means (16) is received when the swing angle of the body is within a predetermined swing range position with respect to the undercarriage and the hydraulic pressure acting on the boom cylinder (15) exceeds the set pressure. Arm cylinder (12),
Electromagnetic switching that shuts off pilot pressure between the control pressure valve (6a, 6b, 7a, 8a) and the operating valve (2, 3, 4) to regulate the movement of the bucket cylinder (13) and the swing motor (11) The lateral posture stabilizing device for a hydraulic excavator according to claim 1, further comprising valves (10a, 10b, 10c, 10d).