JPH0863248A - Mulfunction preventing device for operation device - Google Patents

Abstract

PURPOSE: To provide the malfunction preventing device for the operation device which switches a safety lock valve smoothly. CONSTITUTION: This device is equipped with a hydraulic pressure pump 11, an arm cylinder 13, a boom cylinder 14, a direction control valve 16 for an arm, a direction control valve 17 for a boom, a pilot valve 18 and an operation lever 2 included in the operation device for the arm cylinder 13, a pilot valve 19 and an operation lever 3 included in the operation device for the boom cylinder 14, and the safety lock valve 21 which is provided to a pilot duct 20 connecting the pilot valves 18 and 19 and a pilot pump 12 and connects and disconnects the pilot duct 20; and a touch switch 4 for switching the safety lock valve 21 is arranged on the flank of the operation lever 2 and a touch switch 5 for switching the safety lock valve 21 is arranged on the flank of the operation lever 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an erroneous operation preventing device for an operating device which is provided in a construction machine such as a hydraulic excavator and prevents an actuator from being operated by an operator.

[0002]

2. Description of the Related Art In a construction machine such as a hydraulic excavator, a hydraulic pump, a front actuator such as a boom cylinder, an arm cylinder, a bucket cylinder, etc., which is driven by pressure oil discharged from the hydraulic pump, and a swing motor are generally used. Actuators such as a left traveling motor and a right traveling motor, a traveling body including a boom, an arm, a bucket, a revolving structure, a left crawler belt and a right crawler belt which are actuated by these actuators, and a hydraulic pump to supply each of the actuators. A directional control valve for controlling the flow of pressure oil and an operating device for controlling the drive of these directional control valves are provided. This operating device includes, for example, an operating lever arranged near the driver's seat, and a pilot valve that generates a pilot pressure for driving the directional control valve with the rotation of the operating lever. Further, for example, a pair of the above-mentioned operating devices is provided for driving the front actuator and a pair for driving the left and right traveling motors.

Further, an erroneous operation preventing device for the operating device is provided in order to prevent the actuator from unintentionally operating. This erroneous operation prevention device is turned off when a switch arranged in association with the operating lever of the operating device, for example, the entire operating device including the operating lever is largely rotated forward beyond the operating area of the normal operating lever.
Limit switch and O of this limit switch
And a safety lock valve that is switched to the lock position in accordance with the FF operation. This safety lock valve is provided in a pilot line that connects the pilot valve that constitutes the operating device and the pilot pump. This safety lock valve connects the pilot valve to the tank when switched to the locked position, thereby holding the relevant directional control valve in a neutral state. In this state, the actuator is kept inoperable even if the operation lever is operated. Further, when the operating device including the operating lever is returned to the original position, the above-mentioned limit switch is turned on, and the safety lock valve is switched to the unlocked position, the pilot pump and the pilot valve communicate with each other. In this state, the pilot pressure is applied to the drive unit of the corresponding directional control valve via the pilot valve according to the operation of the operation lever, and the directional control valve is switched. Therefore, the pressure oil of the hydraulic pump is supplied to the corresponding actuator via the directional control valve, and this actuator can be driven at a speed corresponding to the operation amount of the operation lever.

As described above, in the hydraulic excavator equipped with the erroneous operation preventing device for the operating device, for example, when the operator sitting in the driver's seat stops working and goes out of the operator's cab, the entire operating device including the operating lever is used. It is designed so that it can be pushed out to the outside by pushing it to the front. As a result, the limit switch is turned off and the safety lock valve is switched to the lock position as described above, and the actuator does not operate even if the operation lever is moved. Therefore, for example, when the operator enters the operator's cab again and accidentally touches the operating lever of the operating device in a collapsed state and the operating lever moves, the actuator does not operate and The boom, arm, etc. do not operate, and the safety of the hydraulic excavator with respect to the surrounding environment and the safety of the operator are ensured.

When the operator sitting in the driver's seat restarts the work, the entire operation device including the operation lever is largely rotated toward the front side to return to the original position. As a result, the safety lock valve is switched to the unlocked position as described above, and the actuator can be driven according to the operation of the operation lever, that is, the front of the boom, arm, bucket, etc. can be driven, run, and swiveled. Excavation work can be performed.

As a conventional erroneous operation preventing device for an operating device, in addition to the structure in which the operating device including the operating lever is largely rotated to actuate the limit switch as described above, and the safety lock valve is switched in response thereto. , Some have a grip switch on the knob of the operating lever.

In the prior art having the grip switch as described above, the safety lock valve is switched to the unlocked position by the ON operation by gripping the grip switch, and the actuator can be operated according to the operation amount of the operation lever. Further, the safety lock valve is switched to the lock position by the OFF operation by releasing the grip of the grip switch, and the actuator is kept inoperable even if the operation lever moves.

[0008]

In the former prior art described above, that is, in the one in which the limit switch is operated by largely rotating the operating device including the operating lever, the lock position switching operation of the safety lock valve or Each time the lock release position switching operation is performed, it is necessary to rotate the entire operation device including the operation lever, and thus the operation of switching the safety lock valve becomes complicated.

Further, in the latter prior art, that is, in the case of gripping or releasing the grip switch to switch the safety lock valve to the lock position or the lock release position, it is necessary to turn the grip switch on and off considerably. Grip force is required, and the operation of switching the safety lock valve becomes complicated from the viewpoint different from the above.

Therefore, in any of the above-mentioned conventional techniques, the operator is annoyed and tired in a situation where the switching operation of the safety lock valve is repeatedly performed within a relatively short working time.

The present invention has been made in view of the above-mentioned circumstances in the prior art, and an object thereof is to provide an erroneous operation preventing device for an operating device capable of lightly performing a switching operation of a safety lock valve. .

[0012]

In order to achieve this object, a first aspect of the present invention is a hydraulic pump, an actuator driven by pressure oil discharged from the hydraulic pump, and Construction having a directional control valve for controlling the flow of pressure oil supplied from the hydraulic pump to the actuator, and an operating device having an operating lever arranged near the driver's seat and generating a signal for driving the directional control valve A switch provided on the machine and arranged in association with the operating device, and a safety lock valve that responds to the operation of the switch, and when the safety lock valve is switched to the lock position in response to the operation of the switch. , The directional control valve is held in a neutral state regardless of the operation of the operation lever of the operation device, and the operation of the actuator is disabled accordingly. When the safety lock valve is switched to the unlocked position in response to the operation of the switch, the directional control valve is switched in response to the operation of the operation lever of the operation device, and the operation that enables the operation of the actuator is performed. In the erroneous operation preventing device of the apparatus, the switch is a touch switch, and the touch switch is arranged in a specific area on the surface of the operation lever that is away from the area facing the driver's seat.

According to a second aspect of the present invention, in the above-mentioned first aspect of the invention, the specific region includes either the side surface or the rear surface of the operation lever. is there.

According to a third aspect of the present invention, in the invention according to the first or second aspect, the operation lever is a pair of front actuator levers, and the touch switch is provided. On each of these front actuator levers,
ON at least one of these touch switches
In response to the operation, the control device outputs a switching signal for switching the safety lock valve to the unlocked position.

According to a fourth aspect of the present invention, in the above-mentioned first or second aspect of the invention, the operation lever is a pair of front actuator levers and a pair of traveling levers. In addition, the touch switch is provided on each of the pair of front actuator levers and each of the pair of travel levers, and the safety lock valve is activated in response to an ON operation of at least one of the touch switches. The control device outputs a switching signal for switching to the unlocked position.

According to a fifth aspect of the present invention, in the above-mentioned first or second aspect of the invention, the operation lever is a pair of front actuator levers, and the touch switch is provided. On each of these front actuator levers,
The control device outputs a switching signal for switching the safety lock valve to the unlocked position in response to both ON operations of these touch switches.

According to a sixth aspect of the present invention, in the above-mentioned first or second aspect of the invention, the operation lever is a pair of front actuator levers and a pair of traveling levers. In addition, the touch switch is provided on each of the pair of front actuator levers and each of the pair of travel levers, and at least two of the touch switches are provided.
The control device outputs a switching signal for switching the safety lock valve to the unlocked position in response to one ON operation.

[0018]

According to the first aspect of the present invention, since the switch for activating the safety lock valve is a touch switch provided on the operation lever, the touch switch is operated with a light force such that a hand is brought into contact with the operation lever. Can be turned on, and can be turned off by releasing the hand from the operating lever, and the switching operation of the safety lock valve can be performed easily. Further, in this case, since the touch switch is arranged in a specific area on the surface of the operation lever that avoids the area facing the driver's seat, the body of the operator trying to sit in the driver's seat or leaving the operator's seat Does not touch the touch switch, and an erroneous operation of the operation lever, that is, an operation of the actuator not intended by the operator does not occur.

The invention according to claim 2 of the present invention is
In addition to the same effect as that of the invention described in claim 1 described above, since the specific region where the touch switch is arranged includes either the side surface or the back surface of the operation lever, the operator operates the operation lever when driving the actuator. When gripped, the touch switch immediately turns on, and when the grip is released, the touch switch immediately turns off.

The invention according to claim 3 of the present invention is
In addition to the same operation as the invention according to claim 1 or 2 described above, the touch switch is immediately turned on by the control device when at least one of the pair of front actuator levers is operated, and the safety lock valve Is switched to the unlocked position, and the corresponding front actuator can be driven.

The invention according to claim 4 of the present invention is
At least one of the pair of front actuator levers and the pair of traveling levers is controlled by the control device, in addition to the same effect as that of the invention described in claim 1 or 2 described above.
When one of them is operated, the touch switch is immediately turned on, the safety lock valve is switched to the unlocked position, and the corresponding front actuator and travel motor can be driven.

The invention according to claim 5 of the present invention is
In addition to the same effect as the invention described in claim 1 or 2, the touch switch is turned on for the first time when both the pair of front actuator levers are operated by the control device, and the safety lock valve is locked. By being switched to the unlocked position, a dual unlocking system for the operation of the front actuator is formed.

Further, the invention according to claim 6 of the present invention is
In addition to the same effect as the invention according to claim 1 or 2, the control device controls at least two of the pair of front actuator levers and the pair of traveling levers.
When one of them is operated, the touch switch is turned on for the first time, and the safety lock valve is switched to the unlocked position, so that a dual unlocking system for the operation of the actuator including the front actuator and the traveling motor is formed.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an erroneous operation preventing device for an operating device of the present invention will be described below with reference to the drawings. 1 to 3 are views for explaining a first embodiment corresponding to claims 1, 2 and 3 of the present invention, FIG. 1 is a plan view for explaining a mounting position of a touch switch, and FIG. 2 is for FIG. FIG. 3 is an enlarged arrow view in the direction A, and FIG. 3 is a circuit diagram showing the overall configuration of the first embodiment. These Figure 1,
The first embodiment shown in 2 and 3 is provided, for example, in a hydraulic excavator.

First, the overall construction of the first embodiment will be described with reference to FIG. As shown in FIG. 3, in the first embodiment, a prime mover 10, a main hydraulic pump 11 driven by the prime mover 10, and a pilot pump 12 are provided.
And a tank 33. In addition, the main hydraulic pump 1
1 is supplied to the arm cylinder 13 from the main hydraulic pump 11 and an actuator driven by pressure oil discharged from the main pipe 15, for example, an arm cylinder 13 that drives an arm (not shown), a boom cylinder 14 that drives a boom (not shown). The arm directional control valve 16 for controlling the flow of the pressure oil to be generated and the boom directional control valve 17 for controlling the flow of the pressure oil supplied from the main hydraulic pump 11 to the boom cylinder 14 are provided. The arm cylinder 13 and the boom cylinder 14 described above form a front actuator together with a bucket cylinder (not shown).

Further, an operating device including an operating lever 2 for operating the arm directional control valve 16 and a pilot valve 18 responsive to the operating lever 2 is provided, and the pilot valve is operated in accordance with the operating direction of the operating lever 2. The pilot pressure is selectively supplied from 18 to one of the drive units 16a and 16b of the arm directional control valve 16. Similarly, the operating lever 3 for operating the boom directional control valve 17
And a pilot valve 19 that responds to the operating lever 3, and is provided with a boom directional control valve 17 from the pilot valve 19 depending on the operating direction of the operating lever 3.
The pilot pressure is selectively supplied to either of the drive units 17a and 17b.

Further, in the pilot line 20 connecting the pilot pump 12 and the pilot valves 18 and 19,
A safety lock valve 21 is provided. This safety lock valve 21
Shuts off the pilot line 20 and causes the pilot valve 18,
Lock position 21a, which will be described later, for connecting 19 to the tank 33.
And a lock release position 21b, which will be described later, that allows the pilot conduit 20 to communicate with each other. This safety lock valve 21
When switched to the lock position 21a, the operation levers 2, 3
Regardless of the operation, the arm directional control valve 16 and the boom directional control valve 17 are held in a neutral state, the operation of the arm cylinder 13 and the boom cylinder 14 is disabled, and the lock release position 21b is set. When switched, the arm directional control valve 1 is operated according to the operation of the operation levers 2 and 3.
6. The directional control valve 17 for the boom is switched, and the arm cylinder 13 and the boom cylinder 14 can be operated.

In the first embodiment, touch switches 4 and 5 are provided as switches for switching the safety lock valve 21 described above. These touch switches 4, 5
As shown in FIGS. 1 and 2, the specific area 3 on the surface of the operation levers 2 and 3 avoiding the area 34 facing the driver's seat 1.
5, for example, on the side surfaces of the operation levers 2 and 3, respectively. These touch switches 4 and 5 are connected to the control device 22 by signal lines. The control device 22 determines whether or not at least one of the touch switches 4 and 5 is turned on, and when at least one of the touch switches 4 and 5 is turned on, the drive portion 21c of the safety lock valve 21 unlocks the safety lock valve 21. It includes an output means for outputting a drive signal for switching to 21b.

For example, when the operating lever 2 is operated in the direction of arrow 6, the arm directional control valve 16 is switched, and when it is operated in the direction of arrow 7, the directional control valve for driving a slewing motor (not shown) is switched, and the operating lever is operated. When 3 is operated in the direction of arrow 8, the boom directional control valve 17 is switched,
When operated in the direction of arrow 9, a bucket directional control valve for driving a bucket (not shown) can be switched. That is, the operation levers 2 and 3 described above form a front actuator lever that switches the arm cylinder 13, the boom cylinder 14, and the bucket cylinder that are front actuators.

In the first embodiment constructed as described above, the touch switches 4 and 5 are respectively turned on only by the operator gripping the operation levers 2 and 3, and if the operator releases his or her hand from the operation levers 2 and 3. The touch switches 4 and 5 are immediately turned off.

For example, in order for an operator who is sitting in the driver's seat 1 and performing desired excavation work to go out of the operator's cab,
When the hands of both the operation levers 2 and 3 are released to stop the operation of the actuator, the touch switches 4 and 5 are both turned off. The control device 22 determines that the signals output from the touch switches 4 and 5 are both OFF, and outputs a low level drive signal to the drive portion 21c of the safety lock valve 21. Accordingly, the safety lock valve 21 is
It is switched to the lock position 21a by the force of the spring, the pilot conduit 20 is shut off, and the pilot valves 18, 1
9 communicates with the tank 33. In this state, even if the operation lever 2 or the operation lever 3 is operated, the pilot pressure is not applied to the drive parts 16a and 16b of the arm directional control valve 16 or the drive parts 17a and 17b of the boom directional control valve 17. Not supplied, these directional control valves 16 and 17 are kept in a neutral state. Therefore, even if the operation levers 2 and 3 are operated, the arm cylinder 13 and the boom cylinder 14 are held stationary.

Further, when the operator sits in the driver's seat 1 to resume the desired work and, for example, grips the operation lever 2, the touch switch 4 is immediately turned on and the control device 2
2 determines that the signal output from the touch switch 4 is ON, and outputs a high-level drive signal to the drive unit 21c of the safety lock valve 21. Along with this, the safety lock valve 21
Is switched to the lock position against the force of the spring, and the pilot conduit 20 is in communication. In this state,
Depending on the operation amount of the operation lever 2, the pilot pump 12
Pilot pressure of pilot line 20, safety lock valve 2
1. Direction control valve 16 for arm via pilot valve 18
Is supplied to either of the drive units 16a and 16b, and the arm directional control valve 16 is switched. Along with this, the pressure oil of the main hydraulic pump 11 is supplied to the arm cylinder 13 via the main pipe line 15 and the arm direction control valve 16, and the arm cylinder 13 operates to move an arm (not shown).

The same applies to the case of operating the operation lever 3, and when the touch switch 5 is turned on and the safety lock valve 21 is switched to the unlocked position 21b.
The boom (not shown) can be moved by performing speed control of the boom cylinder 14 according to the operation amount of the operation lever 3.

Further, the same applies to the case where the operation lever 2 and the operation lever 3 are operated at the same time. Based on the ON signal of the touch switches 4 and 5 which is input earlier, the control device 22 outputs a high level signal. The drive signal is output to the drive portion 21b of the safety lock valve 21, and the safety lock valve 21
Is switched to the unlocked position 21b, and the operation lever 2,
By performing speed control of the arm cylinder 13 and the boom cylinder 14 according to the operation amount of 3, the combined drive of the arm and boom (not shown) can be performed.

Further, in the first embodiment, the touch switches 4 and 5 are arranged in the specific area 35 avoiding the area 34 facing the driver's seat 1 on the surface of the operation levers 2 and 3, There is no risk that the operator's body trying to sit in the driver's seat 1 or the operator trying to leave the driver's seat 1 will not touch the touch switches 4, 5, and the operation lever 2,
The operation of the arm cylinder 13 and the boom cylinder 14 which is not intended by the operator does not occur, and the safety of the hydraulic excavator with respect to the surrounding environment and the safety of the operator are basically ensured.

In the first embodiment constructed as described above, since the operation levers 2 and 3 are provided with the touch switches 4 and 5, they are touched with a light force such that the hands are brought into contact with the operation levers 2 and 3. The switches 4 and 5 can be turned on, and can be turned off by releasing the operating levers 2 and 3, so that the switching operation of the safety lock valve 21 can be performed easily. Therefore, the operator is not bothered and tired due to the switch operation.

The touch switches 4 and 5 are located on the side surfaces of the operation levers 2 and 3, that is, the operator operates the operation levers 2 and 3.
When the operator grips the operation levers 2 and 3, the touch switches 4 and 5 are immediately turned on when the arm cylinder 13 and the boom cylinder 14 are driven, since Further, when the grip is released, the touch switches are immediately turned off, and the ON / OFF operations of the touch switches 4 and 5 can be directly connected to the driving operations of the arm cylinder 13 and the boom cylinder 14 naturally. There is no special awareness of the operation.

When at least one of the operation levers 2 and 3 is operated, the corresponding one of the touch switches 4 and 5 is immediately turned on, and the safety lock valve 21 is switched to the unlocked position 21a, and the corresponding condition is obtained. Since the arm cylinder 13 or the boom cylinder 14 can be driven, when the arm cylinder 13 or the boom cylinder 14 starts to be driven, the arm cylinder 13 or the boom cylinder 14 can be quickly driven to follow the operation of the operation levers 2 and 3. Can be realized.

In the first embodiment, a drive signal for switching the safety lock valve 21 to the unlock position 21a when at least one of the touch switches 4 and 5 provided on the operation levers 2 and 3 is turned on. A control device 22 including an output means for outputting to the drive portion 21c of the safety lock valve 21 is provided. Instead of the control device 22, it is determined whether or not both the touch switches 4 and 5 are turned on, and both are turned on. O
A control device may be provided that includes an output unit that outputs a drive signal for switching the safety lock valve 21 to the unlocked position 21a when it is determined to be N to the drive unit 21c of the safety lock valve 21. This structure corresponds to claim 5 of the present invention.

With the above-mentioned structure, the touch switch 4, 4 is operated when both the operation levers 2, 3 are operated.
Both 5 are turned on, a high-level drive signal is output from the control device, and the safety lock valve 21 is in the unlocked position 2
Since it is switched to 1a, when only one unintended operating lever is accidentally operated, the safety lock valve 21 remains held at the lock position 21b, and the corresponding arm cylinder 13 or boom cylinder 14 does not move. Without these arm cylinder 13 and boom cylinder 14
A double lock release system is formed to improve the safety against erroneous operation of the operation levers 2 and 3.

Although the touch switches 4 and 5 are arranged on the side surfaces of the operation levers 2 and 3 in the above-described first embodiment, they may be arranged on the back surface.

4 to 6 are views for explaining a second embodiment corresponding to claims 1, 2 and 4 of the present invention. FIG. 4 is a plan view for explaining a mounting position of a touch switch, and FIG. 4 is a perspective view showing the operation lever portion shown in FIG. 4, and FIG. 6 is a circuit diagram showing the overall configuration. This second embodiment is also provided, for example, in a hydraulic excavator.

In the second embodiment, as shown in FIG.
A left traveling motor 27 that drives a left crawler belt (not shown) and a left traveling direction control valve 29 that controls the flow of pressure oil supplied from the main hydraulic pump 11 to the left traveling motor 27 are provided. A pilot valve 31 for supplying pilot pressure for switching the control valve 29 to its driving portions 29a, 29b, and a left travel lever 23 for operating the pilot valve 31 in response to being operated in the direction of arrow 27a in FIG.
And an operating device consisting of. Similarly, as shown in FIG. 6, a right traveling motor 28 for driving a right crawler belt (not shown)
And a right traveling directional control valve 30 for controlling the flow of pressure oil supplied from the main hydraulic pump 11 to the right traveling motor 28, and a pilot pressure for switching the right traveling directional control valve 30 is supplied to the drive unit thereof. There is provided an operating device including a pilot valve 32 which is supplied to 30a and 30b, and a right travel lever 24 which operates the pilot valve 32 when operated in the direction of arrow 28a in FIG. The pilot valves 31 and 32 described above are respectively connected to the portion of the pilot conduit 20 located downstream of the safety lock valve 21.

In particular, in the second embodiment, the left traveling lever 23 is also provided with a touch switch 25 for switching the safety lock valve 21, and similarly, the right traveling lever 24 is also provided with a touch switch for switching the safety lock valve 21. A switch 26 is provided. These touch switches 25, 26 are provided in a specific area 35, e.g.
It is located on the back of 24. The control device 22 also includes touch switches 25, 2 provided on the travel levers 23, 24.
6, and the touch switches 4 provided on the operation levers 2 and 3 that form the lever for the front actuator described above.
A drive signal for switching the safety lock valve 21 to the unlocked position in response to the ON operation of at least one of
The safety lock valve 21 is configured to include output means for outputting the drive portion 21c.

The other structure is similar to that of the first embodiment described above.

In the second embodiment thus constructed, the operation levers 2 and 3 forming the lever for the front actuator, the left traveling lever 23, and the right traveling lever 24 are not operated and are kept in the neutral state. When all the touch switches 4, 5, 25 and 26 are turned off, the control device 22 controls the touch switches 4, 5, 25 and 26 to be off.
It is determined that all 5, 25, 26 are OFF, and a low level drive signal for switching to the lock position 21a is output to the drive portion 21c of the safety lock valve 21. This allows
Each pilot valve 18, 19, 31, 32 communicates with the tank 33. In this state, the corresponding directional control valves 16, 17, 29, 30 are not switched even if any of the operation levers 2, 3 and the traveling levers 23, 24 are operated, and all are kept neutral. , Applicable arm cylinder 1
3, the boom cylinder 14, the left traveling motor 27, and the right traveling motor 28 are held stationary.

When at least one of the operation levers 2 and 3 and the traveling levers 23 and 24 is operated, the traveling levers 23 and 24 are gripped when the traveling levers 23 and 24 are operated, for example. Then, the touch switches 25 and 26 are turned on, and the control device 22 drives the drive portion 21c of the safety lock valve 21 at a high level in response to the signal of the touch switch 25 or 26 that is turned on earlier. Output a signal. As a result, the safety lock valve 21 is switched to the unlocked position 21b against the spring force. In this state, the pilot conduit 20 communicates, and the pilot pressure corresponding to the operation amount of the traveling levers 23 and 24 corresponds to the drive unit 2 of the left traveling directional control valve 29.
It is supplied to either of 9a, 29b and either of the drive parts 30a, 30b of the corresponding right traveling directional control valve 30. As a result, the directional control valves 29 and 30 are switched to each other, the pressure oil discharged from the hydraulic pump 11 is supplied to the traveling motors 27 and 28, and the traveling motors 2 and 28 are supplied.
7, 28 can be driven at a speed corresponding to the operation amount of the traveling levers 23, 24.

Further, in the second embodiment, the touch switches 4 and 5 are arranged on the side surfaces of the operation levers 2 and 3, and the touch switches 25 and 26 are arranged on the rear surfaces of the traveling levers 23 and 24. , The driver's seat 1 as in the first embodiment
The arm cylinder 13 which is not intended by the operator who is trying to sit on the floor or who is trying to leave the driver's seat 1.
The boom cylinder 14, the left traveling motor 27, and the right traveling motor 28 do not operate, and the safety of the hydraulic excavator with respect to the surrounding environment and the safety of the operator are basically ensured.

Even in the second embodiment having such a configuration, the touch switches 4 and 5 and the touch switches 25 and 2 are attached to the operation levers 2 and 3 and the traveling levers 23 and 24.
Since 6 is provided, these touch switches 4, 5, 2 are provided with a light force such that the operating levers 2, 3 and the travel levers 23, 24 are brought into contact with the hands, as in the first embodiment.
5, 26 can be turned on, and can be turned off by releasing the hands from the operation levers 2, 3 and the travel levers 23, 24, and the switching operation of the safety lock valve 21 can be performed lightly. The operator will not be bothered and tired.

The touch switches 4 and 5 are arranged on the side surfaces of the operation levers 2 and 3, and the touch switches 25 and 2 are arranged.
6 is arranged on the rear surface of the traveling levers 23, 24, that is, any of the touch switches 4,5, 25, 26 is operated by the operator, the operating levers 2, 3, the traveling levers 23, 24.
Since it is arranged at a position where it comes into contact when gripping 24, the arm cylinder 13, the boom cylinder 14, or the left traveling motor 2 is arranged in the same manner as in the first embodiment described above.
7. When driving the right traveling motor 28, when the operator grips the corresponding lever, the touch switches 4, 5, 2
5, 26 are immediately turned on, and when the grip is released, they are immediately turned off.
The ON / OFF operation of 26 can naturally be directly connected to the drive operation of the arm cylinder 13, the boom cylinder 14, the left traveling motor 27, and the right traveling motor 28, and the operator can operate the touch switches 4, 5, 25, 26. There is no special awareness.

The operating levers 2 and 3 and the traveling lever 2
When at least one of the touch switches 3, 5, 24 is operated, the touch switches 4, 5, 2 are operated as in the first embodiment.
The corresponding one of 5 and 26 is immediately turned on, the safety lock valve 21 is switched to the unlock position 21a,
Since the corresponding arm cylinder 13, boom cylinder 14, or left traveling motor 27, right traveling motor 28 can be driven, these arm cylinder 13, boom cylinder 14, left traveling motor 27, right traveling motor 28 operation lever 2 , 3 and the traveling levers 23 and 24 are started, the swivel arm cylinder 13 and the boom cylinder 1 follow the operation of the operation levers 2 and 3 and the traveling levers 23 and 24.
4. Driving of the left traveling motor 27 and the right traveling motor 28 can be realized.

In the second embodiment, when at least one of the touch switches 4 and 5 provided on the operation levers 2 and 3 and the touch switches 25 and 26 provided on the traveling levers 23 and 24 is turned on. In addition, a control device 22 including an output means for outputting a drive signal for switching the safety lock valve 21 to the unlock position 21b to the drive portion 21c of the safety lock valve 21 is provided. Instead of the control device 22, the touch switch 4 is provided. , 5, 25, 26 at least two of them are turned on, and at least two of them are turned on.
It is also possible to provide a control device including output means for outputting a drive signal for switching the safety lock valve 21 to the unlock position 21b to the drive portion 21c of the safety lock valve 21 when it is determined that This structure corresponds to claim 6 of the present invention.

With the above-described structure, when at least two of the operation levers 2 and 3 and the traveling levers 23 and 24 are operated, at least two corresponding touch switches 4, 5, 25 and 26 are touched. The switch is turned on, the control device outputs a high level drive signal,
Since the safety lock valve 21 is switched to the unlocked position 21b, as in the first embodiment, when only one unintended operating lever is accidentally operated, the safety lock valve 2
1 is still held in the lock position 21a, the corresponding arm cylinder 13, boom cylinder 14, or left traveling motor 27, right traveling motor 28 does not move, and these arm cylinder 13, boom cylinder 14, left traveling motor 27 are not moved. , A double unlocking system for the right traveling motor 28 is formed, and the operating levers 2, 3 and the traveling lever 2 are formed.
The safety against erroneous operation of 3, 24 can be improved.

[0054]

According to the invention described in claim 1 of the present invention, since the touch switch is provided as a switch for switching the safety lock valve, the switching operation of the safety lock valve can be performed easily, and the switch operation is accompanied. It does not give the operator the feeling of annoyance and fatigue as in the prior art.

The invention described in claim 2 is the same as claim 1
In addition to the effect of the invention described in (1), the touch switch immediately turns on when the operator grips or releases the grip.
Since it is set to N or OFF, there is an effect that the operator is not particularly conscious of the operation of the touch switch.

The invention described in claim 3 is the same as claim 1
Further, in addition to the effect of the invention described in item 2, there is an effect that when the drive of the front actuator is started, the drive of the front actuator that follows the operation of the operation lever can be quickly performed.

The invention described in claim 4 is the same as claim 1
Further, in addition to the effect of the invention described in item 2, there is an effect that at the time of starting the driving of the front actuator or the traveling motor, it is possible to realize the prompt driving of the front actuator or the traveling motor that follows the operation of the operation lever.

The invention described in claim 5 is the same as claim 1.
Further, in addition to the effect of the invention described in 2, the double unlocking system for the operation of the front actuator is formed, and there is an effect that the safety against the erroneous operation of the front actuator lever can be improved.

The invention described in claim 6 is the same as claim 1.
Alternatively, in addition to the effect of the invention described in 2, the double unlocking system for the operation of the actuator including the front actuator and the traveling motor is formed to improve the safety against the erroneous operation of the front actuator lever or the traveling lever. There is an effect that can be.

[Brief description of drawings]

FIG. 1 is a plan view illustrating a mounting position of a touch switch provided in a first embodiment of an operation error prevention device for an operation device according to the present invention.

FIG. 2 is an enlarged arrow view of direction A in FIG.

FIG. 3 is a circuit diagram showing an overall configuration of a first exemplary embodiment of the present invention.

FIG. 4 is a plan view illustrating a mounting position of a touch switch provided in a second embodiment of the present invention.

FIG. 5 is a perspective view showing a traveling lever portion provided in the second embodiment shown in FIG.

FIG. 6 is a circuit diagram showing an overall configuration of a second exemplary embodiment of the present invention.

[Explanation of symbols]

 1 Driver's Seat 2 Control Lever 3 Control Lever 4 Touch Switch 5 Touch Switch 10 Motor 11 Main Hydraulic Pump 12 Pilot Pump 13 Arm Cylinder 14 Boom Cylinder 15 Main Pipe 16 Arm Directional Control Valve 17 Boom Directional Control Valve 18 Pilot Valve 19 Pilot Valve 20 Pilot line 21 Safety lock valve 22 Control device 23 Left traveling lever 24 Right traveling lever 25 Touch switch 26 Touch switch 27 Left traveling motor 28 Right traveling motor 29 Left traveling direction control valve 30 Right traveling direction control valve 31 Pilot Valve 32 Pilot valve 33 Tank 34 Area part 35 Specific area

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Takishita 650 Kazunachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Tsuchiura factory (72) Inventor Toichi Hirata 650 Kintachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Incorporated Tsuchiura Factory (72) Inventor Yukio Sakamoto 650 Kintatemachi, Tsuchiura City, Ibaraki Prefecture Hitachi Construction Machinery Incorporated Tsuchiura Factory

Claims (6)

[Claims] 1. A hydraulic pump, an actuator driven by pressure oil discharged from the hydraulic pump, a directional control valve controlling a flow of pressure oil supplied from the hydraulic pump to the actuator, and a directional control valve near a driver's seat. A switch provided in a construction machine having an operating lever arranged and having an operating device for generating a signal for driving the directional control valve, the switch arranged in association with the operating device, and a safety responsive to the operation of the switch. A lock valve, and when the safety lock valve is switched to the lock position with the operation of the switch, the directional control valve is held in a neutral state regardless of the operation of the operation lever of the operation device. As a result, the operation of the actuator was disabled, and the safety lock valve was switched to the unlocked position with the operation of the switch. In the erroneous operation prevention device for an operating device, wherein the directional control valve is switched according to the operation of the operating lever of the operating device to enable the operation of the actuator, the switch is a touch switch, and the operation lever An erroneous operation preventing device for an operating device, wherein the touch switch is arranged in a specific area avoiding an area facing the driver's seat on the surface. 2. The specific region includes one of a side surface and a back surface of the operation lever.
An erroneous operation prevention device for the operating device described. 3. The operation lever is a pair of front actuator levers, and the touch switch is provided on each of the front actuator levers, and is responsive to an ON operation of at least one of the touch switches. 3. The erroneous operation prevention device for an operating device according to claim 1, further comprising a control device for outputting a switching signal for switching the safety lock valve to an unlocked position. 4. The operation lever includes a pair of front actuator levers and a pair of traveling levers, and the touch switch is provided to each of the pair of front actuator levers and each of the pair of traveling levers. 3. A control device which is provided and which outputs a switching signal for switching the safety lock valve to an unlocked position in response to an ON operation of at least one of these touch switches. Misoperation prevention device for operating devices. 5. The safety lever is a pair of front actuator levers, and the touch switch is provided on each of the front actuator levers, and the safety is achieved in response to an ON operation of both of these touch switches. The erroneous operation preventing device for an operating device according to claim 1 or 2, further comprising a control device that outputs a switching signal for switching the lock valve to the unlocked position. 6. The operation levers are a pair of front actuator levers and a pair of traveling levers, and the touch switch is provided to each of the pair of front actuator levers and each of the pair of traveling levers. The operation according to claim 1 or 2, further comprising: a control device that outputs a switching signal for switching the safety lock valve to an unlocked position in response to an ON operation of at least two of the touch switches. Device misoperation prevention device.