JPH09242110A - Interference-preventive device of hydraulic construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an interference-preventive device which not only prevents interference with a cab of a working machine, but also improves operability of attachments like an offset or the like provided in the working machine. SOLUTION: Operation buttons 50a, 50b controlling an offset cylinder 9 are arranged on a grip of a control lever 25 for a boom and a bucket. An operator grips the control lever 25 with his right hand and rotates it to actuate the boom cylinder 8 and the bucket cylinder 11. When the working machine has trespassed on the interaction-preventive zone, the operator pushes the control button 50a by a finger to retract the working machine out of the interference- preventive zone by the action of offset cylinder 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interference prevention device for a hydraulic construction machine, which automatically controls the operation of a working machine when the working machine approaches an operator's cab, and avoids a collision between the two. The present invention relates to an interference prevention device for a hydraulic construction machine suitable for use in a construction machine such as a small turning hydraulic excavator having an attachment actuator such as an offset cylinder.

[0002]

2. Description of the Related Art It is known that a hydraulic construction machine such as a hydraulic excavator is additionally provided with an interference prevention device for preventing a collision between the working machine and a driver's cab when the working machine approaches the cab. For example, as described in Japanese Unexamined Patent Publication No. 7-71051, when excavating a working machine, the soil is dumped to a dump truck or the like. Therefore, when performing complex operations such as turning, boom raising, and arm pulling, When the bucket enters the preset interference prevention area around the cab,
An interference prevention device for a hydraulic excavator has been proposed that automatically stops boom raising and arm pulling.

In particular, in a small swing hydraulic excavator having an offset mechanism, when switching from a work posture in which the work implement is extended forward to a small swing posture in which the work implement is pulled toward you and held, the offset is performed while preventing the bucket from spilling. Since it is necessary to operate, the operating lever is operated with both hands to perform turning, boom raising, arm pulling, and horizontal holding of the bucket, and an offset operation is performed by depressing the operating pedal.

Further, in recent hydraulic excavators,
For example, as described in Japanese Patent Application Laid-Open No. 7-238574, a foot-operated accelerator pedal for accelerating an offset operation or the like is provided, and when necessary, the accelerator pedal is operated to perform an offset operation or the like. Also, there has been proposed one in which a fine operation is performed while the accelerator pedal is not operated.

FIG. 7 is a hydraulic circuit diagram for explaining a conventional interference preventing device for a hydraulic excavator, FIG. 8 is a side view showing the overall construction of the hydraulic excavator, FIG. 9 is an explanatory diagram of the inside of the hydraulic excavator, and FIG. It is a block diagram of the interference prevention device.

In FIGS. 7 and 8, 1 is a running body, 2 is a revolving structure having a driver's cab 3 and arranged above the traveling structure 1. The traveling structure 1 and the revolving structure 2 constitute a hydraulic excavator. It constitutes the main body. 4 is an offset boom, 5 is an arm rotatably connected to the tip of the boom 4, and 6 is an arm 5.
Is a bucket that is rotatably connected to the tip of the work machine 7. The boom 4, the arm 5, and the bucket 6 form a working machine 7. The boom 4 includes a first boom 4a rotatably connected to the right side of the cab 3, and a first boom 4a.
Second boom 4 that is connected to the tip of the frame through a connecting member 4b
c. 8 is a boom cylinder that drives the first boom 4a, 9 is an offset cylinder that drives the second boom 4c, 10 is an arm cylinder that drives the arm 5, 11 is a bucket cylinder that drives the bucket 6, and the second boom 4c Is translated laterally with respect to the first boom 4a by the offset cylinder 9.

Further, 12 is a turning motor, 13 is a right traveling motor, 14 is a left traveling motor, 15 and 16 are hydraulic pumps and pilot pumps driven by an engine (not shown), respectively, 17 is a hydraulic pump 15 and the actuators 8 described above. To 14 for controlling the flow rate of the hydraulic oil discharged from the hydraulic pump 15, 18 is a boom control pilot valve, 19 is an arm control pilot valve, and 20 is a bucket control. A pilot valve, 21 is an offset control pilot valve, 22 is a turning control pilot valve, 23 is a right travel control pilot valve, and 24 is a left travel control pilot valve.

As shown in FIG. 9, operating levers 25, 26, 27, 28, an operating pedal 29, an accelerator pedal 30 and the like are installed near the seat 3a in the cab 3. Each of the pilot valves 18 to 24 is interlocked with the operation levers 25, 26, 27, 28 and the operation pedal 29, and for example, the operator operates the right operation lever 25 located on the right front side of the seat 3 a in the cab 3 with the right hand. When it is gripped by and is appropriately operated in the front-back direction, a pilot pressure signal corresponding to the operation amount is supplied from the boom control pilot valve 18 to the boom flow control valve 17, and is supplied to the boom cylinder 8 based on the pilot pressure signal. The amount of pressure oil supplied is controlled. Similarly, when the right operation lever 25 is appropriately operated in the lateral direction, the pressure oil supplied from the bucket flow control valve 17 to the bucket cylinder 11 is changed based on the pilot pressure signal output from the bucket control pilot valve 20. The supply is controlled.

When the left operating lever 26 located on the left front side of the seat 3a is grasped by the left hand and appropriately operated in the front-rear direction, a pilot pressure signal corresponding to the operation amount is output from the turning control pilot valve 22 for turning. The amount of pressure oil supplied to the control valve 17 and supplied to the swing motor 12 is controlled based on the pilot pressure signal. Similarly, when the left operation lever 26 is appropriately operated in the lateral direction, the arm flow control valve 17 to the arm cylinder 10 are operated based on the pilot pressure signal output from the arm control pilot valve 19.
The supply amount of the pressure oil supplied to is controlled.

When the pair of travel levers 27, 28 located in front of the seat 3a are appropriately operated in the front-rear direction, a pilot pressure signal corresponding to the operation amount is used for the right travel control pilot valve 23 and the left travel control. The amount of pressure oil supplied from the pilot valve 24 to each traveling flow control valve 17 and supplied to the right traveling motor 13 and the left traveling motor 14 is controlled based on the pilot pressure signal.

When the operation pedal 29 located on the right side of the traveling lever 27 is properly depressed in the front-rear direction, a pilot pressure signal corresponding to the operation amount is supplied from the offset control pilot valve 21 to the offset flow control valve 17. The supply amount of the pressure oil supplied to the offset cylinder 9 is controlled based on the pilot pressure signal. further,
An accelerator pedal 30 located near the operation pedal 29
When is depressed, the operation of the offset cylinder 9 or the like is accelerated.

As shown in FIG. 10, the interference preventing device 31 of the hydraulic excavator configured as described above has a boom angle sensor 32, an arm angle sensor 33, and an offset angle sensor 34.
And a controller 35 which is connected to these sensors 32 to 34 and includes a CPU, and electromagnetic proportional pressure reducing valves 36, 37, 38 and an electromagnetic proportional valve 39 which are connected to the controller 35. The boom angle sensor 32 is the first
It is provided at the fulcrum of the boom 4a and detects the relative angle between the revolving unit 2 and the first boom 4a. The arm angle sensor 33 is provided at the fulcrum portion of the arm 5, and the second boom 4c and the arm 5 are provided.
Detect the relative angle between. The offset angle sensor 34 is provided at a fulcrum portion of the connecting member 4b and detects a relative angle between the first boom 4a and the connecting member 4b, that is, an offset angle. The controller 35 inputs the angle signal from each of the sensors 32 to 34, and based on the angle signal input to the input unit 40, the tip of the bucket 6 and the cab 3
Is calculated, that is, the bucket 6 is in the cab 3
And an output unit that outputs a pressure reducing signal to the electromagnetic proportional pressure reducing valves 36 to 38 based on a calculation result of the calculating unit 41. It consists of 42.

The boom electromagnetic proportional pressure reducing valve 36 is provided in the boom raising pilot line 43, the arm electromagnetic proportional pressure reducing valve 37 is provided in the arm pulling pilot line 44, and the offset electromagnetic proportional pressure reducing valve 38 is left. It is provided in the offset pilot line 45. The arm proportional solenoid valve 39 is connected on the inlet side to the pilot oil supply pipeline 46 and on the outlet side to the arm pushing pilot pipeline 47.
To the shuttle valve 48.

In FIG. 8, Z is an interference prevention area set around the driver's cab 3, and the interference prevention area Z is stored in the controller 35. The controller 35 stores the sensors 32, 33. , 34, the angle of the work implement 7 is obtained from the angle signals, and when it is determined that the bucket 6 has entered the interference prevention area Z, the operation levers 25, 26 and the operation pedal are operated. Regardless of the instruction signal from 29, the operation of each part of the working machine 7 is automatically stopped so that the bucket 6 does not approach the cab 3 any more.

That is, when the offset cylinder 9 is left offset and the bucket 6 is in front of the operator's cab 3, the bucket 6 approaches the operator's cab 3 when the arm pulling operation and the boom raising operation are performed individually or in combination. Moving in the direction, but the boom lift pilot line 4 of the hydraulic circuit
3, the arm pull pilot line 44 and the left offset pilot line 45 have electromagnetic proportional pressure reducing valves 36, 37, 3
When the bucket 6 enters the interference prevention area Z, the controller 35 first outputs a control signal for operating the electromagnetic proportional pressure reducing valves 37, 38, whereby the pilot conduits 44, Since the pressure oil of 45 is cut off, the left offset operation and the arm pulling operation are prohibited. At this time, the controller 35 outputs a control signal for opening the solenoid proportional valve 39, which causes the pilot pressure supply line 46 to push the arm pushing pilot line 4.
Since the pressure oil is supplied to the valve 7 via the shuttle valve 48, the arm flow control valve 17 is automatically controlled even if the arm 5 is not pushed at this time. The movement in the direction away from, that is, the arm pushing operation is performed. As a result, by performing the boom raising operation, the arm 5 automatically rotates in the direction away from the cab 3, and as a result, the bucket 6 rises along the vertical boundary line of the interference prevention area Z. Further, when the bucket 6 approaches the cab 3 due to the boom raising operation,
The controller 35 outputs a control signal for operating the electromagnetic proportional pressure reducing valve 36, whereby the pressure oil in the boom raising pilot conduit 43 is shut off, so that the boom raising operation is also prohibited.

[0016]

In the conventional hydraulic excavator described above, when the interference prevention device 31 operates during work, the work implement 7 performs an operation contrary to the operator's intention, so that the work implement 7 prevents interference. If it is predicted that the work machine 7 will enter the area Z, the work machine 7 may be operated in a direction away from the interference prevention area Z during work to perform continuous operation. For example, when it is predicted that the bucket 6 is in front of the operator's cab 3 and enters the interference prevention area Z when the working machine 7 is switched from the working attitude extended forward to the small turning attitude as shown in FIG. The operator turns the boom, raises the arm, and horizontally holds the bucket by operating the operation levers 25 and 26 with both hands, and performs the right offset operation by stepping on the operation pedal 29 to move the bucket 6 from the interference prevention area Z. Operate in the direction of escape. However, such a stepping operation requires the operator to step on the operation pedal 29 while holding his / her body with one foot while sitting on the seat 3a, so that not only the operation is unstable, but also the operation lever 2 is operated by the operator's hand.
As compared with the case of handling 5, 26, there is a problem that the operation feeling is inferior and the fine operation is difficult. Note that such a problem is not limited to the above example, and is the same when the bucket 6 is right offset to avoid the interference prevention area Z after the interference prevention device 31 is activated and automatically stopped.

Further, when the accelerator pedal 30 is depressed as necessary, it is necessary to switch from the operation pedal 29 to the accelerator pedal 30, and there is a problem that the stepping operation is complicated and inconvenient. .

As the actuator for driving the attachments, in addition to the offset cylinder for moving a part of the working machine in the lateral direction, a swing cylinder for swinging the working machine at the base, a telescopic cylinder for expanding and contracting the working machine, etc. Is mentioned. Since these swing cylinders and telescopic cylinders are also operated by the foot-operated operation pedal, there are the same problems as in the case of the offset cylinder described above.

The present invention has been made in view of the above-mentioned circumstances of the prior art, and its purpose is not only to prevent interference with the operator's cab of a working machine, but also to attach an attachment such as an offset provided to the working machine. It is an object of the present invention to provide an interference prevention device for a hydraulic construction machine, which can improve the operability when operating a class.

[0020]

According to the present invention, an operating means for operating at least one of a plurality of actuators for driving a working machine is provided in a grip portion of an operating lever for operating another actuator. The operator operates the actuator corresponding to the operation lever by gripping and operating the operation lever, and, for example, when the working machine enters the interference prevention area and automatically stops, the operation means provided on the operation lever is operated. By operating, the work implement is retracted from the interference prevention area.

According to the present invention thus constructed, the operator does not need to step on the operation pedal when operating the attachments such as the offsets provided on the working machine. It can be held to maintain a stable posture. Further, by operating the operating means by hand, a good operation feeling can be obtained and fine operation can be performed. Therefore, not only interference with the operator's cab of the working machine can be prevented, but also operability when operating attachments such as an offset in order to avoid this interference can be improved.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention drives a main body having a driver's cab, a work machine rotatably provided on the side of the driver's cab of the main machine, and each member constituting the work machine. A plurality of actuators for controlling the operation of the work machine in a direction in which the work machine interferes with the cab when the work machine enters an interference prevention area set around the cab. In an interference prevention device for a construction machine, an operating means for operating at least one of the plurality of actuators is provided in a grip portion of an operating lever for operating another actuator, and the corresponding operating means is operated to operate the actuator. Is operated to retract the working machine from the interference prevention area.

The operating means may employ various electric parts such as potentiometers and switches, and the number of them is not limited, but one actuator is composed of a pair of operation buttons which operate in two opposite directions. It is effective to improve operability.

Further, if foot-operated operation pedals are provided in parallel with the operation means, and the same actuator is selectively operated by these operation means and foot-operated operation pedals, various working machines can be used. Can correspond to.

If a foot-operated accelerator pedal for accelerating the actuator operated by the operating means is provided in parallel, fine operation and normal operation of the actuator can be selectively used according to the work content.

The actuator operated by the operating means may be any actuator that drives attachments such as a swing cylinder and a telescopic cylinder, but an offset cylinder is preferable.

[0027]

Embodiments will be described with reference to the drawings.
1 is a hydraulic circuit diagram of a hydraulic excavator equipped with an interference prevention device for a hydraulic construction machine according to a first embodiment of the present invention, FIG. 2 is a block diagram showing the overall configuration of the interference prevention device of FIG. 1, and FIG. FIG. 4 is an explanatory view of the inside of a cab of the hydraulic excavator, and FIG. 4 is an enlarged plan view showing operation buttons provided in the hydraulic excavator,
The parts corresponding to those in FIGS. 7 to 10 are given the same reference numerals.

As shown in FIGS. 1 and 2, in the interference prevention device 49 according to this embodiment, the offset cylinder 9 is different from the conventional interference prevention device 31 shown in FIGS.
Is provided with a pair of operation buttons 50a and 50b for operating the extension direction and the extension direction, respectively, a release button 50c for releasing the range restriction of the interference prevention area Z, and a right offset electromagnetic proportional control controlled by the controller 35. The main difference is that the valve 52 and the left offset electromagnetic proportional valve 53 are provided, and other configurations are basically the same as those of the conventional one. In this embodiment, the foot-operated operation pedal 29 for operating the offset cylinder 9 is the operation buttons 50a, 50.
This foot-operated operation pedal 29 is installed in parallel with b.
A foot-operated accelerator pedal 30 for accelerating the operation of the offset cylinder 9 and the like is also provided in the vicinity of.

As shown in FIG. 3, a pair of operation buttons 50a,
The release button 50c and the release button 50c are arranged on the grip portion 25a of the right operation lever 25.
Is an operation knob for turning on / off the push switch. As shown in FIG. 4, the surface of the right offset operation button 50a located on the right side is provided with a right-pointing triangular display portion 51a indicating the operation direction thereof, and the surface of the left offset operation button 50b located on the left side. Is also provided with a left-sided triangular display portion 51b indicating the operation direction thereof, and the release button 50c is provided below the operation buttons 50a and 50b.
Is located.

The right offset solenoid proportional valve 52 is
The inlet side is connected to the pilot oil supply line 46, and the outlet side is connected to the right offset pilot line 54 via the shuttle valve 55. Further, the left offset electromagnetic proportional valve 53 is connected on the inlet side to the pilot oil supply pipe line 46 and on the outlet side to the left offset pilot pipe line 45 via another shuttle valve 56.

In the first embodiment having such a configuration, the operator grips the right operation lever 25 with the right hand and presses the right operation button 50a with the finger of the right hand, whereby the right offset from the operation button 50a is set. The operation signal is the controller 3
5, and the right offset solenoid proportional valve 52 is opened under the control of the controller 35. As a result, the pilot oil discharged from the pilot pump 16 to the pilot oil supply pipe line 46 is supplied to the offset flow control valve 17 via the right offset electromagnetic proportional valve 52, the shuttle valve 55, and the right offset pilot pipe line 54. As the offset flow control valve 17 moves to the right in FIG. 1,
The offset cylinder 9 extends and the right offset operation is performed. Similarly, by pressing the left operation button 50b with the operator's right finger, the left offset operation signal from the operation button 50b is input to the controller 35, and the left offset electromagnetic proportional valve 53 is controlled by the controller 35. Opens. As a result, the pilot pump 16
The pilot oil discharged from the pilot oil supply pipe line 46 is supplied to the left offset electromagnetic proportional valve 53 and the shuttle valve 56.
And the offset flow control valve 17 is supplied through the left offset pilot line 45, and the offset flow control valve 17 moves to the left in FIG. 1, so that the offset cylinder 9 contracts to perform the left offset operation. Be done.

When a right offset operation is performed by depressing the offset operation pedal 29, a pilot pressure signal corresponding to the operation amount is transmitted from the offset control pilot valve 21 through the shuttle valve 55 and the right offset pilot conduit 54. Is supplied to the offset flow control valve 17,
The amount of pressure oil supplied to the offset cylinder 9 is controlled based on the pilot pressure signal. Similarly, when a left offset operation is performed with the operation pedal 29, a pilot pressure signal corresponding to the operation amount is output from the offset control pilot valve 21 via the shuttle valve 56 and the left offset pilot conduit 45. The supply amount of the pressure oil supplied to 17 and supplied to the offset cylinder 9 is controlled based on the pilot pressure signal.

Also in the first embodiment, the bucket 6 is prevented from approaching the cab 3 by the control of the controller 35 regardless of the instruction signals from the operation levers 25 and 26 and the operation pedal 29. Thus, the operation of each part of the working machine 7 is automatically stopped. That is, when the offset cylinder 9 is left offset and the bucket 6 is in front of the operator's cab 3, when the arm pulling operation and the boom raising operation are performed individually or in combination, and the bucket 6 enters the interference prevention area Z, The controller 35 is an electromagnetic proportional pressure reducing valve 3
A control signal for operating the actuators 7 and 38 is output, whereby the pressure oil in the pilot conduits 44 and 45 described above is cut off, so that the left offset operation and the arm pulling operation are prohibited. At this time, since the controller 35 automatically controls the arm flow control valve 17 even if the arm pushing electromagnetic proportional valve 39 is not opened and the arm pushing operation is performed, the arm 5 moves away from the cab 3. The operation, that is, the arm pushing operation is automatically performed, and the boom raising operation can be performed. Further, when the bucket 6 approaches the cab 3 due to the boom raising operation, the controller 35 outputs a control signal for operating the electromagnetic proportional pressure reducing valve 36, and the pressure oil in the boom raising pilot conduit 43 is cut off, so that the boom raising operation is performed. Movement is also prohibited. In addition, when the bucket 6 enters the interference prevention area Z from the side due to the left offset operation of the boom 4, the controller 35 outputs a control signal for operating the electromagnetic proportional pressure reducing valve 38, whereby the pilot conduit 45 described above is output. Since the pressure oil of is blocked, the left offset operation is prohibited. At that time, the operator operates the operation button 50a.
When is pressed, the boom 4 is offset rightward and the bucket 6 avoids the interference prevention area Z, so that the operation of the work implement 7 can be restarted in this state.

In the first embodiment, it is not always necessary to depress the operation pedal 29 during the offset operation, and the operation button 5 provided on the grip portion 25a of the right operation lever 25 is required.
Since it is sufficient to press 0a and 50b, the operator can hold his / her body with his / her feet and maintain a stable posture while sitting on the seat 3a. In particular, the right operation lever 25 and the operation button 5
Both 0a and 50b can be simultaneously operated by the operator's hand. Further, by pressing the operation buttons 50a and 50b by hand, a good operation feeling can be obtained and fine operation can be performed. Therefore, the working machine 7
Not only can the interference with the driver's cab 3 be prevented, but the operability when operating the offset cylinder 9 to avoid this interference can be improved.

Further, in the first embodiment, when the offset operation is performed while the accelerator pedal 30 is being depressed, the operation buttons 50a and 50b can be pushed by hand,
It is not necessary to change the operation between the offset operation pedal 29 and the accelerator pedal 30, and the operability can be improved from this point as well. Further, since either one of the operation pedal 29 and the operation buttons 50a and 50b can be selectively operated, it can be applied to various uses of working machines. Further, since the accelerator pedal 30 for accelerating the operation of the offset cylinder 9 and the like is installed in parallel, the offset cylinder 9
The operability such as can be improved.

In the above-described first embodiment, the operation buttons 50a and 50b of the push switch have been illustrated as the operation means for operating the offset cylinder 9, but the operation buttons 50a and 50b may be used instead of the operation buttons 50a and 50b. It is also possible to use a joystick type operation body for adjusting the resistance value. In addition, a pair of operation buttons 50a, 5
Although 0b is provided on the right operation lever 25, these may be provided on the left operation lever 26 instead of the right operation lever 25, or may be provided on the right operation lever 25 and the left operation lever 26 separately.

In the first embodiment, the pair of operation buttons 50a and 50b are arranged in the lateral direction.
It is also possible to arrange 0a and 50b in the vertical direction. Also,
The operation buttons 50a and 50b are provided with display portions 51a and 51b, respectively, which indicate the operation direction, on their respective surfaces.
By forming a concave portion or a convex portion indicating the operation direction on each surface of a and 50b, it is possible to identify by so-called blind touch without looking at the operation buttons 50a and 50b.

FIG. 5 is a hydraulic circuit diagram of a hydraulic excavator having an interference preventing device for a hydraulic construction machine according to a second embodiment of the present invention, which corresponds to FIGS. 1 to 4 and 7 to 10 described above. The same reference numerals are given to the parts.

In the interference prevention device 57 according to the second embodiment, the conventional interference prevention device 3 shown in FIGS.
Compared to 1, there is provided a pair of operation buttons 50a and 50b for operating the offset cylinder 9 in the extension direction and the extension direction, respectively, and in that an offset electromagnetic switching valve 58 controlled by the controller 35 is provided. The main difference is that, instead of the offset control pilot valve 21, an electric operation means 59 for interlocking with the operation pedal 29 and inputting an electric signal to the controller 35 is provided, and other configurations are basically conventional. Is equivalent to The offset electromagnetic switching valve 58 has a pilot oil supply line 4 on the inlet side.
6 and the outlet side is the right offset pilot line 5
4 and the left offset pilot line 45.

In the second embodiment, the operator grips the right operation lever 25 with the right hand and holds the right operation button 50 with the right finger.
By pressing a, a right offset operation signal from the operation button 50a is input to the controller 35, and the offset electromagnetic switching valve 58 moves upward in FIG. 5 under the control of the controller 35. As a result, the pilot oil discharged from the pilot pump 16 to the pilot oil supply pipeline 46 is supplied to the offset flow control valve 17 via the offset electromagnetic switching valve 58 and the right offset pilot pipeline 54, and the offset flow control valve 17 is supplied. Since the flow control valve 17 moves to the right in FIG. 5, the offset cylinder 9 extends and the right offset operation is performed. Similarly, by pressing the left operation button 50b with the operator's right finger, the left offset operation signal from the operation button 50b is input to the controller 35, and the offset electromagnetic switching valve 58 is controlled by the controller 35. Move to the bottom of FIG. As a result, the pilot oil discharged from the pilot pump 16 to the pilot oil supply pipe line 46 is supplied to the offset flow control valve 17 via the offset electromagnetic switching valve 58 and the left offset pilot pipe line 45, and the offset flow control valve 17 is supplied. Since the flow control valve 17 moves to the left in FIG. 5, the offset cylinder 9 is contracted and the left offset operation is performed.

When the offset operation pedal 29 is depressed to perform the right offset operation, an electric signal corresponding to the operation amount is output from the electric operation means 59 to the controller 3.
5 is input, and under the control of the controller 35, the offset cylinder 9 extends and the right offset operation is performed in the same manner as when the operation button 50a is operated. Similarly, when the left offset operation is performed with the operation pedal 29, the offset cylinder 9 is contracted and the left offset operation is performed in the same manner as when the operation button 50b is operated.

Even in the second embodiment, when the bucket 6 enters the interference prevention area Z, the controller 35
By the control of 1, the left offset operation and the arm pulling operation are prohibited respectively, and the arm pushing operation is automatically performed. Further, when the bucket 6 approaches the cab 3 due to the boom raising operation, the controller 35 outputs a control signal for operating the electromagnetic proportional pressure reducing valve 36, and the pressure oil in the boom raising pilot conduit 43 is cut off, so that the boom raising operation is performed. Movement is also prohibited.
Further, when the bucket 6 enters the interference prevention area Z from the side due to the left offset operation of the boom 4, the controller 35 outputs a control signal for operating the electromagnetic switching valve 58,
As a result, the pressure oil in the left offset pilot conduit 45 is cut off, and the left offset operation is prohibited.

Also in the second embodiment constructed as above,
The same effect as the first embodiment shown in FIGS. 1 to 4 described above can be obtained.

FIG. 6 is a hydraulic circuit diagram of a hydraulic excavator having an interference preventing device for a hydraulic construction machine according to a third embodiment of the present invention, which corresponds to FIGS. 1 to 5 and 7 to 10 described above. The same reference numerals are given to the parts.

In the interference prevention device 60 according to the third embodiment shown in FIG. 6, the offset cylinder 9 is extended in the extension direction and the extension direction, respectively, as compared with the conventional interference prevention device 31 shown in FIGS. A pair of operation buttons 50a, 5 to be operated
0b is provided, and instead of providing the pilot valves 18 to 24, electrical operation means 61 to 67 for inputting an electrical signal to the controller 35, and a plurality of solenoid valves 68 controlled by the controller 35 are provided. Are mainly different, and other configurations are basically the same as the conventional ones.

Of the electric operation means 61 to 67, the boom operation means 61 and the bucket operation means 63 are interlocked with the right operation lever 25, and the arm operation means 62 and the turning operation means 65 are the left operation lever 26. The operating means 64 for offset is interlocked with the operation pedal 29, and the operating means 66, 67 for traveling are respectively interlocked with the traveling levers 27, 28. An inlet side of each of the plurality of solenoid valves 68 is connected to the pilot oil supply pipeline 46, and an outlet side thereof is connected to each directional control valve 17 via each of the pilot pipelines 43 to 45, 47, 54 and the like.

Also in the third embodiment, when the operator grips the right operation lever 25 with the right hand and appropriately operates, for example, the front direction, the electric operation means 61 is operated according to the operation amount.
An electric signal is input from the controller 35 to the controller 35, and the boom raising solenoid valve 68 is opened under the control of the controller 35. As a result, the pilot oil discharged from the pilot pump 16 to the pilot oil supply pipe line 46 is supplied to the boom flow rate control valve 17 via the boom raising solenoid valve 68 and the boom raising pilot pipe line 43, and is used for the boom. Since the flow control valve 17 moves to the right in FIG. 6, the boom cylinder 8 extends and the boom 4 is raised.
Similarly, when the right operation lever 25 is operated forward, the boom 4 is lowered by the control of the controller 35. The same applies to the other operation levers 26, 27, 28.

When the operator holds the right operation lever 25 with his right hand and presses the right operation button 50a with his right finger, a right offset operation signal from the operation button 50a is input to the controller 35, Controller 3
The solenoid valve 68 for right offset is opened by the control of 5. As a result, the pilot oil discharged from the pilot pump 16 to the pilot oil supply pipe line 46 is supplied to the offset flow control valve 17 via the right offset solenoid valve 68 and the right offset pilot pipe line 54 and used for the offset. Since the flow rate control valve 17 moves to the right in FIG. 6, the offset cylinder 9 extends and the right offset operation is performed. Similarly, by pressing the left operation button 50b with the right finger, a left offset operation signal from the operation button 50b is input to the controller 35, and the controller 3 is operated.
By the control of 5, the left offset solenoid valve 68 opens. As a result, the pilot oil discharged from the pilot pump 16 to the pilot oil supply pipe line 46 is supplied to the offset flow control valve 17 via the left offset electromagnetic valve 68 and the left offset pilot pipe line 45, and the offset oil is supplied. Since the flow rate control valve 17 moves to the left in FIG. 6, the offset cylinder 9 contracts and the left offset operation is performed.

When the offset operation pedal 29 is depressed to perform the right offset operation, an electric signal corresponding to the operation amount is output from the electric operation means 64 to the controller 3.
5 is input, and under the control of the controller 35, the offset cylinder 9 extends and the right offset operation is performed in the same manner as when the operation button 50a is operated. Similarly, when the left offset operation is performed with the operation pedal 29, the offset cylinder 9 is contracted and the left offset operation is performed in the same manner as when the operation button 50b is operated.

Even in the third embodiment, when the bucket 6 enters the interference prevention area Z, the controller 35
The left offset operation and the arm pulling operation are prohibited by the control of 1) and the arm pushing electromagnetic proportional valve 68 is opened to automatically perform the arm pushing operation. Further, when the bucket 6 approaches the driver's cab 3 due to the boom raising operation, the controller 35 outputs a control signal for operating the boom raising solenoid valve 68, and the pressure oil in the boom raising pilot pipe line 43 is cut off. Raising is also prohibited. Further, when the bucket 6 enters the interference prevention area Z from the side due to the left offset operation of the boom 4, the controller 35 outputs a control signal for operating the left offset electromagnetic valve 68, and thereby the left offset pilot conduit. 45
Since the pressure oil of is blocked, the left offset operation is prohibited.

Also in the third embodiment thus constructed, the same effect as that of the first embodiment shown in FIGS. 1 to 4 can be obtained.

[0052]

As described above, according to the present invention,
Since operations such as offsets provided on the work machine can be performed with the hand holding the operation lever, it is not necessary to depress the operation pedal, and the operator can hold the body with both feet while sitting on the seat. And maintain a stable posture. In addition, it is possible to obtain a good feeling of operation and to perform a fine operation by operating it by hand. Therefore, not only interference with the operator's cab of the working machine can be prevented, but also operability when operating attachments such as an offset in order to avoid this interference can be improved.

Further, if a pair of operation buttons that operate arbitrary actuators in two opposite directions are used as the operation means, and these operation buttons are provided in the grip portion of the operation lever,
The operator can operate the operation button with his / her finger while rotating the operation lever, and the combined operation of the operation lever and the operation button becomes easy.

If a foot-operated operation pedal is provided separately from the operation means, the attachments can be operated by selectively operating either one of the operation means and the foot-operated operation pedal. It can be used for various purposes.

Further, when foot-operated accelerator pedals for accelerating the actuators operated by the operating means are provided in parallel, the operation speed of the attachments can be selected by the selective operation of the foot-operated accelerator pedals. It is possible to selectively use the fine operation of the type and the normal operation.

When the actuator operated by the operating means is an offset cylinder, a part of the working machine can be laterally moved by operating the operating means, and a small swing hydraulic excavator having an offset cylinder is provided. Can be applied.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a hydraulic excavator including an interference prevention device for a hydraulic construction machine according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an overall configuration of the interference prevention device of FIG.

FIG. 3 is an explanatory view of the inside of a cab of the hydraulic excavator.

FIG. 4 is an enlarged plan view showing an operation button provided in the hydraulic excavator.

FIG. 5 is a hydraulic circuit diagram of a hydraulic excavator including an interference prevention device for a hydraulic construction machine according to a second embodiment of the present invention.

FIG. 6 is a hydraulic circuit diagram of a hydraulic excavator including an interference prevention device for a hydraulic construction machine according to a third embodiment of the present invention.

FIG. 7 is a hydraulic circuit diagram illustrating a conventional example of an interference prevention device for a hydraulic shovel.

FIG. 8 is a side view showing the overall configuration of the hydraulic excavator.

FIG. 9 is an explanatory view of the inside of a cab of the hydraulic excavator.

FIG. 10 is a block diagram of the interference prevention device.

[Explanation of symbols]

 3a Seat 8 Boom Cylinder 9 Offset Cylinder 11 Bucket Cylinder 25 Operation Lever 25a Grip Part 29 Foot-operated Operation Pedal 30 Foot-operated Accelerator Pedal 35 Controller 49 Interference Prevention Device 50a, 50b Operation Button (Operating Means) 52, 53 Electromagnetic Proportional Valve 57 Interference Prevention device 58 Electromagnetic switching valve 59 Electric operation means 60 Interference prevention device 61-67 Electric operation means 68 Electromagnetic valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Toshiaki Nishida, Toshiaki Nishida, 650 Jinrachi-cho, Tsuchiura, Ibaraki Hitachi Construction Machinery Co., Ltd., Tsuchiura Plant Inside the Engineering Co., Ltd. (72) Ken Iijima, 650 Jinrachicho, Tsuchiura City, Ibaraki Prefecture Tsuchiura Plant, Hitachi Construction Machinery Co., Ltd. (72) Inventor, Hiroshi Watanabe, 650, Kintatecho, Tsuchiura City, Ibaraki Hitachi Construction Machinery Company's Tsuchiura factory (72) Inventor Masakazu Haga 650 Kintate-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd.Tsuchiura factory (72) Inventor Hiroyuki Adachi 650 Kintachi-cho, Tsuchiura, Ibaraki Hitachi Construction Machinery Co. Inside the factory (72) Inventor Yasushi Fukushima 2-13-1, Aize-cho, Hitachi-shi, Ibaraki Hitachi-Kiso Co., Ltd.

Claims (5)

[Claims] 1. A main body having a driver's cab, a working machine rotatably provided on a side of the driver's cab of the main body, and a plurality of actuators for driving respective members constituting the working machine. When the working machine enters an interference prevention area set around the operator's cab, the operation of the working machine is controlled to interfere with the operator's cab. In the device, operating means for operating at least one of the plurality of actuators is provided in a grip portion of an operating lever for operating another actuator, and by operating the operating means to operate a corresponding actuator, An interference prevention device for a hydraulic construction machine, wherein the working machine is retracted from the interference prevention area. 2. The interference prevention device for a hydraulic construction machine according to claim 1, wherein the operation means comprises a pair of operation buttons that respectively operate corresponding actuators in two opposite directions. 3. A foot-operated operation pedal is provided side by side separately from the operation means, and the same actuator is selectively operated by these operation means and foot-operated operation pedal. An interference prevention device for a hydraulic construction machine characterized by the above. 4. The interference prevention device for a hydraulic construction machine according to claim 1, wherein a foot-operated accelerator pedal for accelerating an actuator operated by the operating means is provided in parallel. 5. The interference prevention device for a hydraulic construction machine according to claim 1, wherein the actuator operated by the operating means is an offset cylinder.