JPH10183676A - Hydraulic drive device of hydraulic shovel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cause a blade to perform various kinds of actions without reducing the space in an operation room and without deteriorating the operability of the blade. SOLUTION: When a changeover switch 7 is turned to the front side, upstream side portions 21c-26c of pilot lines are connected to boom up, down lines 22a, b, arm dump grout lines 24a, b, and bucket grout dump lines 26a, b to lead pilot pressure to a direction switching valve 13 which drives a hydraulic actuator of a work front. When the switch 7 is turned to the side of a blade, the portions 21c-26c are connected to blade up, down lines 21a, b, blade left, right angle lines 24a, b, and blade right, left up tilt lines 26a, b, respectively, to lead pilot pressure to a direction switching valve 14 for driving a hydraulic actuator of the blade.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic drive for a hydraulic shovel, and more particularly to a hydraulic drive for a hydraulic shovel having blades.

[0002]

2. Description of the Related Art Conventionally, a hydraulic excavator having a blade is provided with a hydraulic cylinder for elevating and lowering a blade, and an operation lever for extending and retracting the blade hydraulic cylinder to raise and lower the blade is provided with an operation lever for operating a work front. It was provided separately and independently. Then, when performing bladed work using a blade, the hydraulic cylinder is extended to ground the blade, and otherwise, the hydraulic cylinder is contracted to raise the blade from the ground. However, in this case, a space for providing an operation lever for raising and lowering the blade is required separately, and thus there is a problem that the space in the cab is reduced. Therefore, for example, as disclosed in Japanese Patent Application Laid-Open No. 7-247572,
A structure has been proposed in which an operating means for raising and lowering the blade is attached to the operating lever for traveling so that the operating lever for raising and lowering the blade is not required.

[0003]

In recent years, due to the diversification of the blading work, not only the operation of raising and lowering the blade but also the operation of tilting (upward / leftward) and angle (upward / leftward) has been performed. A structure to make it work has been proposed. When the structure of Japanese Patent Application Laid-Open No. 7-247572 is applied as means for operating such an operation, the blade tilt operating means and the blade angle operating means are
It will be attached to each of the other two operation levers. Therefore, when trying to operate the blade up / down / tilt / angle, it is necessary to operate each operation means provided on the three operation levers, which causes a problem that operability at the time of operating the blade deteriorates.

An object of the present invention is to provide a hydraulic drive system for a hydraulic excavator that allows a blade to perform various operations without reducing the space in a cab and without deteriorating the operability of the blade. .

[0005]

According to the present invention, there is provided, in accordance with the present invention, an upper revolving unit, a work front provided on the upper revolving unit, a lower traveling unit, and a lower traveling unit. Hydraulic drive of a hydraulic shovel provided on a hydraulic shovel having a blade to be mounted and having first operating means for operating the work front and the upper revolving unit, and second operating means for operating the blade In the device, a part of the first operating means is shared with the second operating means, and the shared part is used as a part of the first operating means when operating the work front and the upper swing body. Switching means for switching the connection of the shared part so that the shared part is used as a part of the second operating means when the blade is operated. Hydraulic drive system for a hydraulic excavator, wherein the girder is provided. Generally, in a hydraulic excavator equipped with a blade, when operating the blade, the operation of the work front or the upper revolving superstructure is hardly performed. Therefore, in the present invention, the first operating means for operating the work front and the upper revolving structure and the second operating means for operating the blade are partially shared, and the work front and the upper revolving body are operated. When the blade is operated, the common part is used as the first operating means. When the blade is operated, the switching means is used and the common part is used as the second operating means.
This eliminates the need to provide a space for installing the second operation means separately from the first operation means for the common portion, and thus can prevent the space in the cab from becoming narrow. Also, when operating the blade, the first set which is set in consideration of operability in advance.
Since the common part of the operating means is used as the second operating means as it is, the operability at the time of operating the blade does not deteriorate, and good operability can be obtained.

Preferably, in the hydraulic drive device of the excavator, the work front includes a boom rotatably connected to the upper swing body, an arm rotatably connected to the boom, and an arm. And a bucket rotatably connected to the first operating means.
The boom operating means for operating the boom, the arm operating means for operating the arm, the bucket operating means for operating the bucket, the shared portion,
A second common part for the boom provided in the operating means for the boom, a common part for the arm provided in the operating means for the arm, and a common part for the bucket provided in the operating means for the bucket; Operating means for raising and lowering the blade, an operating means for angle operating the blade, and an operating means for tilting the blade for tilting, the switching means includes: Means for operating the work front and the upper revolving structure, the boom common part, the arm common part, and the bucket common part with the boom operating means, the arm operating means, and the bucket When the connection of each common part is switched so as to be used as a part of the operating means, and the blade is operated, The common part for boom, the common part for arm, and the common part for bucket are used as a part of any one of the elevating operation means, the angle operation means, and the tilt operation means respectively corresponding thereto. Thus, there is provided a hydraulic drive device for a hydraulic shovel characterized by switching the connection of each common part.

Preferably, in the hydraulic drive device of the excavator, the work front includes a boom rotatably connected to the upper swing body, an arm rotatably connected to the boom, A bucket rotatably connected to the arm, wherein the first operating means includes a boom operating means for operating the boom, an arm operating means for operating the arm, and an operating means for the bucket. Operating means for the bucket, the common part includes a common part for the boom provided in the operating means for the boom, a common part for the arm provided in the operating means for the arm, and the operating means for the bucket. A second common operation means for raising and lowering the blade, and an angle operation of the blade. And angle manipulation means for,
Tilt operation means for tilting the blade, wherein the switching means is configured to use the common part for the boom as a part of the operation means for the boom when operating the boom. Boom switching means for switching the connection of the parts, and arm switching means for switching the connection of the arm common parts so as to use the arm common parts as a part of the arm operating means when operating the arm. A bucket switching unit for switching the connection of the bucket shared part so as to use the bucket shared part as a part of the bucket operating means when operating the bucket;
These boom switching means, arm switching means, and bucket switching means, when operating the blade,
The common part for boom, the common part for arm, and the common part for bucket are used as a part of any one of the operation unit for elevation, the operation unit for angle, and the operation unit for tilt, respectively. A hydraulic drive device for a hydraulic shovel, characterized in that the connection of each common part is switched so that the connection can be performed independently of each other. As a result, the switching between the boom operation and the blade lifting / lowering operation, the switching between the arm operation and the blade angle operation, and the switching between the bucket operation and the blade tilt operation can be performed independently of each other, so that finer switching can be performed according to the work mode. Becomes

[0008] More preferably, in the hydraulic excavator hydraulic drive device, the boom switching means, when operating the blade, switches the boom shared portion of the second operating means other than the elevating operating means. A hydraulic drive device for a hydraulic shovel, characterized in that the connection of the common part for the boom is switched so as to be used as a part of the hydraulic excavator. That is, the boom operation means and the elevating operation means are not shared, and the blade operation and the boom operation can be performed simultaneously. Thereby, during the bleeding work, when there is a concern that the earth and sand in front of the blades will increase with the progress of the work and come into contact with the bucket,
This can be avoided by raising the boom.

Preferably, in the hydraulic drive system for the hydraulic excavator, the first operating means includes at least one
A hydraulic drive device for a hydraulic shovel, wherein the switching means includes a changeover switch, and the changeover switch is provided on any one of the operation levers. Provided. Thereby, operability at the time of performing the switching operation can be improved.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIG. The hydraulic drive device according to the present embodiment is a known hydraulic excavator having a blade, for example,
It is applied to a hydraulic excavator described in JP-A-98258. FIG. 2 is a side view showing the entire structure of the excavator, and FIG. 3 is a top view showing the structure of a blade mounting portion of the excavator shown in FIG. 2 and 3, the excavator includes a lower traveling body 101,
It has a blade 110 mounted on the lower traveling structure 101 via an arm 107, an upper revolving structure 102, and a work front 150 provided on the upper revolved structure 102. , A boom 151 rotatably connected to the upper swing body 102, an arm 152 rotatably connected to the boom 151, and a bucket 153 rotatably connected to the arm 152.
And

The lower traveling body 101 is a truck frame 1
An arm 107 is provided on the track frame 106 so as to be vertically swingable. A bracket 118 is attached to the tip of the arm 107 so as to be rotatable around a vertical axis P. Blade 1
Reference numeral 10 is attached to the bracket 118 via a ball bearing 109 so as to be rotatable around an axis O in the front-rear direction. Further, between the bracket 118 and the blade 110, there are provided link members 116, 116 for connecting these two so as to be relatively swingable. At this time, a ball bearing is also provided at each connecting portion between the link member 116, the blade 116, and the bracket 118.

A connecting frame 117 is bridged over the arm 107, a rod portion of a blade lifting / lowering cylinder 113 is rotatably connected to the connecting frame 117, and a bottom portion of the blade lifting / lowering cylinder 113 is a track. It is pivotally connected to the frame 106. Thus, the blade 110 can be moved up and down by the expansion and contraction of the blade lifting cylinder 113.

The rod portions of the blade tilt cylinders 114a and 114b are rotatably connected to the vicinity of both ends of the blade 110, respectively.
8 is rotatably connected to the center side. This allows
Extension of the cylinder 114a and contraction of the cylinder 114b,
Alternatively, by contracting the cylinder 114a and extending the cylinder 114b, the blade 110 can be tilted rightward or leftward (as viewed from the operator).

The rods of the blade angle cylinders 12a and 12b are rotatably connected to both ends of the bracket 118, respectively, and the bottom portions of the blade angle cylinders 12a and 12b are rotatable with the arm 107. It is connected to. Thereby, the cylinder 12
a and the cylinder 12b contracts, or the cylinder 12
The contraction of a and the extension of the cylinder 12b allow the left end (as viewed from the operator) of the blade to be angled forward or the right end to be angled forward.

FIGS. 1 and 4 are hydraulic circuit diagrams showing a hydraulic drive device of the present embodiment provided in the above-described hydraulic excavator. FIG. 1 shows a circuit of a pilot system, and FIG. 4 shows a typical portion of a circuit other than the pilot system. 1 and 4, an engine (not shown)
The hydraulic pump 10 driven by the hydraulic pump 10 and a boom cylinder 154 (FIG.
Arm cylinder 11, bucket cylinder 155)
(See FIG. 2), a swing motor (not shown), left and right traveling motors (not shown), and a blade lifting / lowering cylinder 113.
(See FIG. 2), blade angle cylinders 12a, 1
2b, blade tilt cylinders 114a, 114b
(See FIG. 2), a plurality of operating lever devices including operating lever devices 1 to 4 provided for operating each of the hydraulic actuators 11, 12, etc .; Direction switches for controlling the flow rate of the pressure oil supplied to the hydraulic actuators 11, 12 and the like, which are connected between the hydraulic actuators 11, 12 and the like, and are controlled by operation signals from the operation lever devices 1 to 4, etc. A valve is provided. However,
FIG. 1 shows only the direction switching valve 13 for the arm, and FIG. 4 shows this example with the direction switching valve 14 for the blade angle. The above constitutes a hydraulic drive device for driving a driven member of a hydraulic shovel.

The work front 150, the upper swing body 102, the lower traveling body 101, and the blade 11
Numeral 0 forms driven members driven by the hydraulic actuators 11, 12 and the like, and their operations are instructed by the operation lever devices 1 to 4 and the like. The operation lever devices 1 to 4 are of a hydraulic pilot type called a pilot operation device which outputs a pilot pressure as an operation signal and drives the corresponding directional control valves 13, 14 and the like. And an operating lever device 2 for arm / blade angle, an operating lever device 3 for bucket / blade tilt, and an operating lever device 4 for turning. As shown in FIG. 1, each of the operation lever devices 1, 2, 3, 4 has an operation lever 1a, 2a, 3a, 4a operated by an operator.
And pressure reducing valves 1b, 2 for generating pilot pressures according to the operation amounts and operation directions of the operation levers 1a, 2a, 3a, 4a.
b, 3b, 4b.

The primary ports of the pressure reducing valves 1b, 2b, 3b, 4b are connected to a hydraulic source 8 (for example, a pilot pump driven by an engine), and the secondary ports are connected to pilot lines 21, 22, 23, 24, 25, 26, 27,
28 are connected to hydraulic drive units 13a, 13b and 14a, 14b, etc. of the corresponding direction switching valves 13, 14, etc.

The pilot lines 21 to 28 include a boom raising / blade raising pilot line 21, a boom lowering / blade lowering pilot line 22, an arm dump / blade left angle pilot line 23,
Arm cloud blade right angle pilot line 24, bucket cloud blade right up tilt pilot line 25, bucket dump blade left up tilt pilot line 26, left turn pilot line 27, right turn Pilot line 28
And is formed from Of these, the pilot lines 21, 22, 23, 24, 25, and 26 have two lines 21a and 21b, 22a and 22 on the downstream side, respectively.
b, 23a and 23b, 24a and 24b, 25a and 25b, 26a and 26b, and switching valves 31, 32, 33, 34, 35, and 36 are provided at these branch points, respectively. That is, the upstream portion 21c of the boom raising / blade raising pilot line 21 is selectively connected to the boom raising pilot line 21a and the blade raising pilot line 21b via the switching valve 31, and the boom lowering / blade lowering is performed. Pilot line 2
2 is selectively connected to a boom lowering pilot line 22a and a blade lowering pilot line 21b through a switching valve 32, and is connected to an arm dump / return valve.
The upstream portion 23c of the blade left angle pilot line 23 is selectively connected to the arm dump pilot line 23a and the blade left angle pilot line 23b via the switching valve 33, and is used to selectively control the arm cloud blade right angle pilot. The upstream portion 24c of the line 24 is selectively connected to the arm cloud pilot line 24a and the blade right angle pilot line 24b via the switching valve 34,
An upstream portion 25c of the blade rising tilt pilot line 25 is selectively connected to a bucket cloud pilot line 25a and a blade rising tilt pilot line 25b via a switching valve 35, and the bucket dump blade is raised left. An upstream portion 26c of the tilt pilot line 26 is selectively connected to a bucket dump pilot line 26a and a blade left-up tilt pilot line 26b via a switching valve 36.

The switching valves 31 to 36 are switched by hydraulic pressure from a hydraulic pressure source 8 guided through an electromagnetic switching valve 30 driven by a signal from a changeover switch 7. That is, when the changeover switch 7 is set to the "front side" position, the drive signal is not output and the electromagnetic changeover valve 30 is set to the upper position in FIG. 1 by the restoration spring, and the pilot pressure from the hydraulic power source 8 is not guided to the changeover valves 31 to 36. The switching valves 31 to 36 are in the upper position in FIG. 1, and the upstream portions 21c to 26c of the pilot lines 21 to 26 are respectively provided with a boom raising pilot line 21a, a boom lowering pilot line 22a, and an arm dumping pilot line 23a. , Arm cloud pilot line 24a, bucket cloud pilot line 25a,
It is connected to the bucket dump pilot line 26a. As a result, the pilot pressure is reduced to the work front 150.
To the driving units such as the direction switching valve 13 for driving the hydraulic actuators 11, 12 and the like. On the other hand, when the changeover switch 7 is set to the "blade side" position, a drive signal is output and the electromagnetic changeover valve 30 is set to the lower position in FIG. Valves 31 to 3
6 is at the lower position in FIG.
The upstream portion 21c to 26c of the blade 26 includes a blade raising pilot line 21b, a blade lowering pilot line 21b, a blade left angle pilot line 23b, a blade right angle pilot line 24b, and a blade right upward tilt pilot line 2 respectively.
5b, Pilot line 26 for tilting blade up left
b. As a result, the pilot pressure is guided to a driving unit such as the direction switching valve 14 that drives the hydraulic actuators 12, 113, and 114 of the blade 110.

Among the plurality of operating lever devices, the operating levers 1a to 4a of the operating lever devices 1 to 4 include the operating lever 1a and the operating lever 2a formed as one lever, and the operating lever 3a and the operating lever 4a. Are formed as one lever, that is, what is called a multi-lever 170. As a result, two actuator operations can be performed with one lever operation. This is shown in FIGS. 5 (a) and 5 (b). FIG. 5A shows an example of an actuator operation that can be operated by the multi-lever when the changeover switch 7 is at the “front side” position, and corresponds to the operation direction viewed from the operator in the cab 160. The vertical direction in the figure is the front-back direction in the cab 160, and the horizontal direction in the figure is the left-right direction in the cab 160. As shown in the figure, two levers 170L (see also FIG. 2) and 170R are provided on the left and right sides of the driver's seat 163. In this case, the right lever 170R is a lever for a boom and a bucket. The left lever 170L serves as an arm and a turning lever. The boom 15 is used to operate the right lever 170R in the front-rear direction.
Operation to lower and raise 1 and operation to the left and right are bucket 1
This is an operation for performing 53 cloud dumps. Then, for example, when the lever is pulled to the left front 170R, the combined operation of the boom raising and the bucket cloud can be performed. The left and right operations of the left lever 170L are performed by turning the upper revolving unit 102 right and left, and the left and right operations are performed by the arm 15
This is the operation for performing the second dump cloud. Then, for example, when the lever 170L is pulled rightward, a combined operation of turning left and arm cloud can be performed. On the other hand, FIG.
FIG. 5B shows an example of an actuator operation that can be operated by the multi-lever 170L, 170R when the changeover switch 7 is at the “blade side” position.
As in (a), it corresponds to the operation direction viewed from the operator in the cab 160. In this case, the right lever 170R is a lever for raising and lowering and tilting the blade, and the left lever 170R is
L represents a blade angle and a lever for turning. The right-and-left lever 170R is operated in the front-rear direction
The operation of lowering / raising 0, the left / right direction is blade 1
This is an operation to perform a right ascending and a left ascending of 10. For example, when the lever 170L is pulled toward the left, the blade 110
Can be tilted to the right while being raised. Further, the left and right operation of the left lever 170L is performed by
This is the operation to perform the left angle and right angle of. Note that the front-rear direction operation of the left lever 170L is an operation of turning right and left similarly to FIG. 5A.

Further, of the plurality of operation lever devices,
The operation levers 171L (see FIG. 2) and 171R (not shown) for operating the right traveling motor are provided with a multi-lever 170.
L and 170R, which are provided further in front of the driver's seat 163, and the changeover switch 7 for switching the changeover valves 31 to 36 is, as shown in FIG. 6, one of the traveling operation levers 171L and 171R. Or one of them. Thereby, the operability when performing the switching operation of the switching valves 31 to 36 can be improved.

In the above structure, the upstream side portions 21c-26c of the pilot lines 21-26, such as the operation lever devices 1-4, and the front pilot lines 21
a to 26a, pilot lines 27 and 28, direction switching valve 13 and the like, and hydraulic actuators 11, 151 and 153
And the like constitute first operation means for operating the work front 150 and the upper swing body 102, and the operation lever devices 1 to 3,
Upstream portions 21c-26 of pilot lines 21-26
c and pilot lines 21b to 26 for operation of each blade
b, direction switching valve 14, etc., blade cylinders 12, 11
3, 114 constitute a second operating means for operating the blade 110. Also, the operation lever devices 1 to 3 and the upstream portions 21c to 26c of the pilot lines 21 to 26 are
A part shared by the first operating means and the second operating means constitutes a changeover switch 7, an electromagnetic switching valve 30, and a switching valve 3
1 to 36 are the work front 150 and the upper revolving superstructure 102.
When operating the blade 110, the connection of the shared part is used such that the shared part is used as a part of the first operating means, and when the blade 110 is operated, the shared part is used as a part of the second operating means. A switching means for switching is constituted. Further, the operation lever device 1, the pilot line 21,
The upstream side portions 21c, 22c of 22 and the boom raising / lowering pilot lines 21a, 22a, the boom direction switching valve (not shown), and the boom cylinder 154 constitute the boom operating means, and the operating lever device 2, the pilot The upstream portions 23c and 24c of the lines 23 and 24, the pilot lines 23a and 24a for the arm dump cloud, the directional control valve 13 for the arm, and the arm cylinder 11 constitute the arm operating means, and the operating lever device 3, the pilot line 25, 26 and the pilot lines 25a, 26 for the bucket dump cloud.
a, a bucket direction switching valve (not shown), and a bucket cylinder 155 constitute bucket operating means. Further, the operation lever device 1 and the pilot lines 21 and 22
Upstream part 21c, 22c constitutes a common part for the boom, and the operation lever device 2 and the pilot lines 23, 24
The upstream side parts 23c, 24c of the armature constitute a common part for the arm, and the operation lever device 3 and the pilot lines 25, 26
Upstream portions 25c and 26c constitute a shared portion for buckets. Also, an operation lever device 1, a pilot line 2
1, 22 upstream-side portions 21c, 22c, blade elevating pilot lines 21b, 22b, blade elevating direction switching valve (not shown), and blade elevating cylinder 1
13 constitutes an elevating operation means for elevating and lowering the blade 110, the operation lever device 2, the pilot line 2
3 and 24 and pilot lines 23b and 24 for the left and right angles of the blade.
b, the angle direction switching valve 14 and the angle cylinder 12 constitute an angle operating means for operating the blade 110 at an angle, and include the operating lever device 3, the upstream portions 25c and 26c of the pilot lines 25 and 26, and The pilot lines 25b and 26b for tilting the blade upward and downward and tilting leftward, a directional switching valve (not shown) for tilting, and a cylinder 114 for tilting
Constitute tilt operation means for tilting the camera. The operation of the above hydraulic drive will be described below. (1) Operation of work front 150 and upper swing body 102
When the turning operation of the arm 15 is performed, for example, the operator
2 is intended to be dumped, the changeover switch 7 is set to the "front side", the changeover valves 31 to 36 are set to the upper position in FIG. 1, and the left lever 170L shown in FIG. What is necessary is to move the operating lever 2a of the operating device 2 for the arm / blade angle in the direction A in FIG. Then, the pilot source pressure from the hydraulic pressure source 8 is changed by the pressure reducing valve 2b to a pressure proportional to the operation amount of the operation lever 2a and output to the upstream portion 23c of the pilot line 23. At this time, the upstream portion 23
c is connected to the arm dump pilot line 23a by the switching valve 33, and this pressure is applied to the hydraulic drive unit 13a of the blade angle direction switching valve 13 via the arm dump pilot line 23a, Is switched to the left position in FIG. Thereby, the pressure oil from the hydraulic pump 10 is supplied to the bottom side of the arm cylinder 11 and the arm cylinder 11
Is operated to extend, and the arm 152 is moved to dump. Here, when the operator intends to cloud the arm 152, the operator may move the left lever 170L shown in FIG. 5A to the right (operation of the operating device 2 for the arm / blade angle in FIG. 1). This corresponds to moving the lever 2a in the direction B). Then, the pilot source pressure from the hydraulic pressure source 8 is changed by the pressure reducing valve 2b to a pressure proportional to the operation amount of the operation lever 2a, and is output to the upstream portion 24c of the pilot line 24.
At this time, since the upstream portion 24c is connected to the arm cloud pilot line 24a by the switching valve 34, this pressure is applied to the arm cloud pilot line 24a.
The signal is supplied to the hydraulic drive unit 13b of the direction switching valve 13 via a, and the spool of the direction switching valve 13 is switched to the right position in FIG. Thereby, the pressure oil from the hydraulic pump 10 is supplied to the rod side of the arm cylinder 11, the arm cylinder 11 is operated to contract, and the arm 152 is moved to crowd. In the case where the operator intends to stop the arm 152, FIG.
The left lever 170L shown in (a) may be returned to the neutral position (corresponding to returning the operating lever 2a of the arm / blade angle operating device 2 to the neutral position). Then
The pressure reducing valve 2 b connects the upstream portions 23 c and 24 c of the pilot lines 23 and 24 to the tank 9, and
The application of the pilot pressure to the arm 152 is released, and the directional control valve 13 is returned to the neutral position by the restoring spring.
Stops. In the above description, the case where the arm 152 is dumped and clouded has been described.
The same applies to the case of raising / lowering, dump / cloud of the bucket 153, and right / left turning of the upper swing body 102. By performing such a lever operation alone or in an appropriate combination, the work front 150 can be bent in a desired manner or the upper swing body 102 can be turned at a desired speed to perform an excavation loading operation or the like.

(2) When operating the blade 110 For example, when the operator intends to make the blade 110 to the left angle, the changeover switch 7 is set to “blade side” and the changeover valves 31 to 36 are set downward in FIG. 5B, the left lever 170L shown in FIG. 5B may be moved to the left (corresponding to moving the operation lever 2a of the arm / blade angle operation device 2 in the A direction in FIG. 1). Then, the pilot source pressure from the hydraulic pressure source 8 is changed by the pressure reducing valve 2b to a pressure proportional to the operation amount of the operation lever 2a, and the upstream portion 23c of the pilot line 23 is changed.
Is output to At this time, the upstream portion 23c is connected to the switching valve 33.
Is connected to the pilot line 23b for the blade left angle, this pressure is applied to the hydraulic drive unit 14a of the direction switching valve 14 via the blade left angle pilot line 23b, and the spool of the direction switching valve 14
The position is switched to the left position in FIG. Thus, the pressure oil from the hydraulic pump 10 is supplied to the cylinder 1 for the blade angle.
2a is supplied to the rod side and the bottom side of the cylinder 12b, the cylinder 12a is operated so as to contract, the cylinder 12b is operated so as to extend, and the blade 110 is at a left angle (the left end of the blade 110 moves forward as viewed from the operator). Moved to do. Here, when the operator intends to make the blade 110 right-angled, the operator may move the left lever 170L shown in FIG. 5B to the left (in FIG. 1, the operating device 2 for the arm / blade angle). This corresponds to moving the operation lever 2a in the direction B). Then, the pilot source pressure from the hydraulic pressure source 8 is changed by the pressure reducing valve 2b to a pressure proportional to the operation amount of the operation lever 2a, and the upstream portion 24c of the pilot line 24 is changed.
Is output to At this time, the switching portion 34
Is connected to the blade right-angle pilot line 24b, so that this pressure is applied to the hydraulic drive unit 14b of the direction switching valve 14 via the blade right-angle pilot line 24b, and the spool of the direction switching valve 14 is
The position is switched to the right position in FIG. Thus, the pressure oil from the hydraulic pump 10 is supplied to the cylinder 1 for the blade angle.
The rod 12b is supplied to the rod side and the bottom side of the cylinder 12a, the cylinder 12b is operated so as to contract, the cylinder 12a is operated to extend, and the blade 110 is at a right angle (the right end of the blade 110 moves forward as viewed from the operator). Moved to do. When the operator intends to stop the angle operation of the blade 110, the left lever 170L shown in FIG. 5B may be returned to the neutral position (the operation lever 2a of the arm / blade angle operation device 2). To the neutral position). Then, the pressure reducing valve 2b is connected to the pilot line 23,
24, the upstream portions 23c and 24c are connected to the tank 9,
The application of the pilot pressure to the direction switching valve 14 is released, the direction switching valve 14 is returned to the neutral position by the restoring spring, and the angle operation of the blade 110 stops. In addition,
In the above description, the case where the blade 110 is left-angled and right-angled has been described.
Left tilt / Right tilt (blade 11 viewed from the operator)
The same applies to the case where the left end and the right end of 0 are raised. By performing such a lever operation alone or in an appropriate combination, the blade 110 can be operated in a desired manner and various bleeding operations can be performed. At this time, if the left lever 170L shown in FIG. 5B is moved in the front-rear direction, the turning operation described in (1) can be performed simultaneously.

The hydraulic drive device of the present embodiment configured as described above has the following effects. In general, in a hydraulic shovel provided with the blade 110, when the blade 110 is operated, the work front 150 and the upper swing body 102 are hardly operated. Therefore, in the present embodiment, the operation lever devices 1 to 4 and the upstream portions 21c to 26c of the pilot lines 21 to 26 are used for both the operation of the work front 150 and the upper swing body 102 and the operation of the blade 110. When operating the work front 150 and the upper swing body 102, the switching valves 31 to 36 are switched to the upper position in FIG. 1 and the shared portion is used to operate the work front 150 and the upper swing body 102. When the blade 110 is operated, the switching valves 31 to 36 are switched to the lower position in FIG. 1 and the common part is used for operating the blade 110. Accordingly, it is not necessary to newly provide an operating lever device for the blade separately from the operating lever devices 1 to 4, so that it is possible to prevent the space in the cab 160 from being narrowed. In addition, the number of parts can be reduced as compared with a case where a blade operating lever device is newly provided separately from the operating lever devices 1 to 4, so that there is also an effect that costs can be reduced. Further, when operating the blade 110, the work front 150 and the upper revolving unit 1 are operated.
Multi-lever 170 installed for turning operation of 02
Since the operation can be performed by L, 170R, good operability can be obtained.

In the above-described embodiment, the changeover switch 70 is provided on the traveling operation levers 171L and 171R. However, the present invention is not limited to this.
R may be provided.

A second embodiment of the present invention will be described with reference to FIG. This embodiment is an embodiment in which the structure and the switching method of the switching valve are different. The same members as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 7 is a hydraulic circuit diagram showing a pilot system circuit in the hydraulic drive device of the present embodiment, and is a diagram corresponding to FIG. 1 of the first embodiment. In FIG. 7, switching valves 31 to 3 are particularly different from the first embodiment.
6, electromagnetic switching valves 230a to 230c are provided, and signals from the same three switching switches 207a to 207c as the switching switch 7 of the first embodiment are output to perform independent switching for each. is there. That is, when the changeover switches 207a to 207c are set to the “front side” position, no drive signal is output and the electromagnetic changeover valve 230
a to c are the upper positions in FIG.
The upstream-side portions 21c to 26c of 1 to 26 include a boom raising pilot line 21a, a boom lowering pilot line 22a, an arm dumping pilot line 23a, an arm cloud pilot line 24a, a bucket cloud pilot line 25a, and a bucket, respectively. It is connected to the dump pilot line 26a. On the other hand, when the changeover switches 207a to 207c are set to the "blade side" positions, a drive signal is output and the electromagnetic switching valves 230a to 230c are switched to the lower positions in FIG.
The upstream portions 21c to 26c of the blades 26 to 26 respectively have a blade raising pilot line 21b, a blade lowering pilot line 21b, a blade left angle pilot line 23b, a blade right angle pilot line 24b, and a blade right upward tilt pilot line. 25b, pilot line 2 for tilting the blade to the left
6b. Further, these changeover switches 207a
Are different from the changeover switch 7 of the first embodiment and are provided on a console (not shown) in the cab 160. Other structures are almost the same as those of the first embodiment.

In the above configuration, the changeover switch 2
07a and the electromagnetic switching valve 230a constitute arm switching means for switching the connection of the arm common part so that the arm common part is used as a part of the arm operating means when operating the arm 152.
b and the electromagnetic switching valve 230b constitute boom switching means for switching the connection of the boom common part so as to use the boom common part as a part of the boom operating means when operating the boom 151, and a changeover switch 207c When the bucket 153 is operated, the electromagnetic switching valve 230c constitutes bucket switching means for switching the connection of the bucket shared part so as to use the bucket shared part as a part of the bucket operating means.

According to the present embodiment configured as described above, in addition to the same effects as those of the first embodiment, the boom can be raised.
Switching between lowering operation and blade raising / lowering operation, switching between arm dump / cloud operation and blade left angle / right angle operation, and switching between bucket dump / cloud operation and blade left / upward / rightward tilt operation are independent of each other. Can be switched more finely according to the work mode.

In the first and second embodiments, the boom raising operation and blade raising operation, the boom lowering operation and blade lowering operation, the arm dump operation and the blade left angle operation, the arm cloud operation and the blade right angle operation , The bucket dump operation and the blade upward tilt operation, and the bucket cloud operation and the blade upward tilt operation were associated with each other and switched between them. However, the present invention is not limited to this, and the combination of these operations can be appropriately changed according to the application. May be. In these cases, a similar effect is obtained. However, regarding this combination of operations,
The following modifications may be made for other purposes. FIGS. 8 and 9 show a hydraulic drive device according to this modification.
This will be described with reference to (a) and FIG. 9 (b).

FIG. 8 is a hydraulic circuit diagram of a pilot system, and corresponds to FIG. 7 of the second embodiment. In FIG. 8, the points different from the second embodiment are that the boom raising / lowering and the bucket cloud dump in the combination of operations are switched, the bucket cloud operation and the blade raising operation, the bucket dump operation and the blade lowering operation, the boom lowering. The operation is associated with the blade upward tilt operation, the boom lowering operation, and the blade upward tilt operation, and these are mutually switched. FIGS. 9A and 9B show the operation directions of the multi-lever 170L and 170R associated therewith.

FIG. 9A shows changeover switches 207a to 207c.
Indicate the operation of the actuator that can be operated by the multi-lever 170L, 170R when all are at the “front side” position, which corresponds to FIG. 5A of the first embodiment. As can be seen from comparison with FIG.
In the right lever 170R, the boom raising / lowering and the bucket cloud dump are switched, the forward / backward operation is an operation to perform a cloud dump of the bucket 153, and the left / right operation is an operation to lower / up the boom 151. Such a modification has the following effects.

That is, for example, the changeover switches 207a to 207a
8, the electromagnetic switching valves 230a to 230c are switched to the lower positions in FIG. 8, and when the bleeding operation is performed, the earth and sand in front of the blade 110 increases as the operation proceeds, and contacts the bucket 153. May be a concern. In such a case, the changeover switch 207c may be switched to the "front side" and the electromagnetic switching valve 230c may be restored to the upper position in FIG. FIG. 9B shows an actuator operation operable by the multi-lever 170L, 170R at this time. As shown in FIG. 9, at this time, the boom 1 is
Since the operation of the blade 51 can be performed, it is possible to prevent the earth and sand from contacting the bucket 153 by operating the right lever 170R to the left to raise the boom 151 while the blade raising / lowering operation, which is a basic operation in bleeding, is continued. it can.

In the above description, in the combination of the operations in FIG.
The dump was replaced, but it is not limited to this. That is, the boom raising / lowering and the arm cloud dump may be exchanged, or the boom raising / lowering and the right turn / left turn may be exchanged. In the latter case, the changeover switch 2
07, the operation of the boom 151 can always be performed by the operation lever devices 4a and 4b.
By the switching operation of 7b, it is possible to selectively switch between performing the left / right turning operation and the blade raising / lowering operation with the operation lever device 1. In short, the connection is switched so that the means for operating the boom 151 and the means for raising and lowering the blade 110 are not shared, so that the blade raising and lowering operation, which is a basic operation in bleeding, and the boom raising and lowering operation can be performed simultaneously. In such cases, the same effect can be obtained.

A third embodiment of the present invention will be described with reference to FIG. This embodiment is an embodiment in which an operation lever device having a so-called electric lever is provided. Members equivalent to those in the first and second embodiments are denoted by the same reference numerals, and description thereof is omitted. FIG. 10 is a hydraulic circuit diagram illustrating a pilot system circuit in the hydraulic drive device of the present embodiment. In FIG. 10, instead of the operation lever devices 1 to 4,
Operation lever devices 310 to 317 having operation levers 310 a to 317 a are provided, respectively, a controller 326 to which operation signals from the operation lever devices 310 to 317 are input, and an output signal from the controller 326 are provided. This embodiment differs from the first embodiment in particular in that electromagnetic pressure reducing valves 318 to 325 for reducing the pressure oil from the hydraulic pressure source 8 are provided. That is, the operation lever devices 310 to 3
Reference numeral 17 denotes an operation lever device 310 for turning left, an operation lever device 311 for turning right, an operation lever device 312 for tilting the bucket cloud / blade to the right, and an operation lever device 313 for tilting the bucket dump / blade to the left.
And the operating lever device 314 for raising the boom and raising the blade
And the operating lever device 315 for boom lowering and blade lowering
And an operation lever device 316 for an arm dump blade left angle and an operation lever device 317 for an arm cloud blade right angle. The operation lever devices 310 to 317 are connected to the operation lever 310.
are provided with potentiometers 310b to 317b for detecting the operating positions of a to 317a and outputting corresponding electric signals, respectively. The controller 326 performs a predetermined operation based on the electric signals from the potentiometers 310b to 317b, and performs the corresponding operations. Electromagnetic pressure reducing valve 318-3
The drive signal is output to 25. Electromagnetic pressure reducing valve 318-325
The primary port side is connected to the hydraulic pressure source 8, and the secondary port side is connected to the corresponding pilot lines 21 to 28. The operation lever devices 310 to 317 are, as in the first embodiment, multi-positioned so that the actuator operation shown in FIG. 5A or FIG. The two levers 170L and 170R are combined as a lever. Other structures are almost the same as those of the first embodiment.

In the above-mentioned hydraulic drive device, for example, the operator intends to dump the arm 152 and sets the changeover switch 7 to the "front side" to move the left lever 170L shown in FIG. In FIG. 10, this corresponds to moving the operation lever 316a of the operation device 316 for the left angle of the arm dump blade. 326 outputs the electromagnetic pressure to the electromagnetic pressure reducing valve 324. As a result, the pilot source pressure from the hydraulic pressure source 8 is changed to a pressure proportional to the operation amount and output to the upstream portion 23c of the pilot line 23. Subsequent steps are the same as in the first embodiment. In addition, when the operator cloudes the arm 152, FIG.
(A) When the middle left lever 170L is moved rightward, a drive signal corresponding to the operation amount is output from the controller 326 to the electromagnetic pressure reducing valve 325, and the pilot source pressure is changed to a pressure proportional to the operation amount, thereby changing the pilot line 24. Is output to the upstream portion 24c. Subsequent steps are the same as in the first embodiment. Further, when the operator stops the arm 152, when the left lever 170L in FIG. 5A is returned to the neutral position, a drive signal corresponding thereto is transmitted to the controller 326.
Are output to the electromagnetic pressure reducing valves 324 and 325, and the electromagnetic pressure reducing valves 324 and 325 connect the upstream-side portions 23 c and 24 c of the pilot lines 23 and 24 to the tank 9. Subsequent steps are the same as in the first embodiment. In addition, boom raising / lowering,
The same applies to the case of performing a bucket dump / cloud and a right / left turn. In order to operate the blade 110, it is sufficient to set the changeover switch 7 to "blade side", set the changeover valves 31 to 36 to the lower position in FIG. 1, and perform the corresponding operation by the operation lever devices 310 to 317 described above. Since the flow of the signal and the pilot pressure at that time is basically the same as that at the time of the above-described front operation, detailed description will be omitted.

According to this embodiment, the same effects as those of the first embodiment can be obtained.

In the first to third embodiments, the operation direction of each actuator operation in the multi-lever 170L, 170R is shown in FIGS. 5 (a) and 5 (b).
However, the arrangement is not limited to this. For example, the left lever 170L may be a boom and bucket lever, the right lever 170L may be an arm and pivot lever, the left lever 170L may be a boom and pivot lever, and the right lever may be an arm and bucket lever. The arrangement of the operation directions is not particularly limited. In these cases, a similar effect is obtained.

[0039]

According to the present invention, it is not necessary to provide a space for installing the second operating means separately from the first operating means, so that it is possible to prevent the space in the cab from becoming narrow. it can. Further, when operating the blade, the shared portion of the first operating means, which is installed in advance in consideration of the operability, is used as it is as the second operating means, so that the operability at the time of operating the blade may be deteriorated. And good operability can be obtained.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram illustrating a pilot system in a hydraulic drive device according to a first embodiment of the present invention.

FIG. 2 is a side view illustrating an entire structure of a hydraulic shovel to which the hydraulic drive device of FIG. 1 is applied.

FIG. 3 is a top view illustrating a structure of a blade mounting portion of the excavator illustrated in FIG. 2;

FIG. 4 is a hydraulic circuit diagram showing a representative portion other than a pilot system in the hydraulic drive device according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating the operation of each actuator that can be operated by a multi-lever.

FIG. 6 is a diagram showing a structure of a changeover switch shown in FIG.

FIG. 7 is a hydraulic circuit diagram illustrating a pilot system in a hydraulic drive device according to a second embodiment of the present invention.

FIG. 8 is a hydraulic circuit diagram showing a pilot system in a modified example.

FIG. 9 is a diagram illustrating the operation of each actuator that can be operated by a multi-lever in a modified example.

FIG. 10 is a hydraulic circuit diagram illustrating a pilot system in a hydraulic drive device according to a third embodiment of the present invention.

[Explanation of symbols]

1. Operating lever device (operating means for boom, first operating means, operating means for lifting and lowering, second operating means, common part for boom, common part) 2 Operating lever device (operating means for arm, first operation Means, angle operating means, second operating means,
Common part for arm, common part) 3 Operation lever device (Operating means for bucket,
A first operation unit, a tilt operation unit, a second operation unit,
Common part for bucket, common part for bucket 4 operating lever device (first operating means) 7 changeover switch (switching means) 11 arm cylinder (operating means for arm,
First operating means) 12a, b Cylinder for blade angle (operating means for angle, second operating means) 13 Direction switching valve for arm (operating means for arm, first operating means) 14 Direction switching valve for blade angle (Angle operating means, second operating means) 21 Boom raising / blade raising pilot line 21a Boom raising pilot line (boom operating means, first operating means) 21b Blade raising pilot line (elevating operating means) , Second operating means) 21c upstream part (boom operating means, first
Operating means, elevating operating means, second operating means, common part for boom, common part) 22 Boom lowering / blade lowering pilot line 22a Boom lowering pilot line (boom operating means, first operating means) 22b Pilot line for lowering blade (operating means for elevating and lowering, second operating means) 22c Upstream portion (operating means for boom, first operating means)
Operating means, elevating operating means, second operating means, common part for boom, common part for use 23 pilot line for arm dump blade left angle 23a pilot line for arm dump (operating means for arm, first operation Means) 23b Pilot line for left angle of blade (angle operating means, second operating means) 23c Upstream portion (arm operating means, first operating means)
Operating means, angle operating means, second operating means, common part for arm, common part) 24 Pilot line for arm cloud blade right angle 24a Pilot line for arm cloud (operating means for arm, first operation Means) 24b Pilot line for right angle of blade (angle operating means, second operating means) 24c Upstream portion (arm operating means, first operating means)
25 Operation means for angle, operation means for angle, second operation means, common part for arm, common part) 25 Pilot line for bucket cloud blade tilting rightward 25a Pilot line for bucket cloud (operating means for bucket, first Operating means) 25b Pilot line for tilting the blade upward right (tilting operating means, second operating means) 25c Upstream portion (bucket operating means, first operating means, tilt operating means, second operating means, Common part for bucket, common part for bucket 26 Pilot line for bucket dump / blade left tilt 26a Pilot line for bucket dump (bucket operating means, first operating means) 26b Pilot line for blade left tilt tilt (tilt operation) Means, second operating means) 26c upstream side Minute (bucket operating means, first operating means, tilt operating means, second operating means, bucket common use part, common use part) 27 Left turn pilot line (first operation means) 28 Right turn Pilot line (first operating means) 30 electromagnetic switching valve (switching means) 31 to 36 switching valve (switching means) 101 lower traveling body 102 upper revolving body 110 blade 113 blade lifting cylinder (elevating operating means, second 114a, b Blade tilt cylinder (tilt operating means, second operating means) 150 work front 151 boom 152 arm 153 bucket 154 boom cylinder (first operating means,
Boom operating means) 155 Bucket cylinder (first operating means, bucket operating means) 170L, R Multi lever (operating lever) 171L Running operating lever (operating lever) 207a Changeover switch (arm changing means) 207b Changeover switch (Switching means for boom) 207c Switch (switching means for bucket) 230a Electromagnetic switching valve (switching means for arm) 230b Electromagnetic switching valve (switching means for boom) 230c Electromagnetic switching valve (switching means for bucket)

Claims (5)

[Claims] 1. A hydraulic shovel comprising an upper revolving unit, a work front provided on the upper revolving unit, a lower traveling unit, and a blade mounted on the lower traveling unit side. In a hydraulic drive system for a hydraulic shovel having first operating means for operating the upper revolving superstructure and second operating means for operating the blade, a part of the first operating means may be replaced with the second operating means. When operating the work front and the upper revolving structure, the shared portion is used as a part of the first operating means, and when operating the blade, the shared portion is used as the second A hydraulic drive device for a hydraulic excavator, further comprising switching means for switching connection of the common part so as to be used as a part of an operation means. 2. The hydraulic drive device for a hydraulic shovel according to claim 1, wherein the work front includes a boom rotatably connected to the upper swing body, and an arm rotatably connected to the boom. A bucket rotatably connected to the arm, wherein the first operating means includes a boom operating means for operating the boom, an arm operating means for operating the arm, and the bucket A common operation part for the boom provided in the operation means for the boom, a common part for the arm provided in the operation means for the arm, and a common part for the bucket. A bucket common part provided in the operating means, wherein the second operating means is an operating means for elevating and lowering the blade, and the blade is operated at an angle. An operating device for an angle for tilting and an operating device for tilting the blade for tilting operation, wherein the switching device is configured to operate the work front and the upper revolving unit when the boom shared portion, The connection of each common portion is switched so as to use the common portion for the arm and the common portion for the bucket as a part of the operating device for the boom, the operating device for the arm, and the operating device for the bucket, respectively. When operating, the common part for the boom, the common part for the arm,
And switching the connection of each common portion so that the common portion for the bucket is used as a part of any one of the operating device for elevation, the operating device for the angle, and the operating device for tilt corresponding to each other. A hydraulic drive system for a hydraulic excavator, comprising: 3. The hydraulic drive device for a hydraulic shovel according to claim 1, wherein the work front includes a boom rotatably connected to the upper swing body, and an arm rotatably connected to the boom. A bucket rotatably connected to the arm, wherein the first operating means includes a boom operating means for operating the boom, an arm operating means for operating the arm, and the bucket A common operation part for the boom provided in the operation means for the boom, a common part for the arm provided in the operation means for the arm, and a common part for the bucket. A bucket common part provided in the operating means, wherein the second operating means is an operating means for elevating and lowering the blade, and the blade is operated at an angle. And a tilt operating means for tilting the blade. The switching means is a part of the boom operating means when operating the boom. Boom switching means for switching the connection of the boom common part so as to be used as the arm, and the arm common part such that the arm common part is used as a part of the arm operating means when operating the arm. Arm switching means for switching the connection of the bucket, and bucket switching means for switching the connection of the bucket common part so as to use the bucket common part as a part of the bucket operating means when operating the bucket. These boom switching means, arm switching means, and bucket switching means operate the blade. When you are,
The common part for boom, the common part for arm, and the common part for bucket are used as a part of any one of the operation unit for elevation, the operation unit for angle, and the operation unit for tilt, respectively. A hydraulic drive device for a hydraulic shovel, characterized in that the connection of each common part is switched so that the connection can be performed independently of each other. 4. The hydraulic drive device for a hydraulic shovel according to claim 2, wherein the boom switching means, when operating the blade, causes the common part for the boom to move up and down of the second operating means. A hydraulic drive device for a hydraulic shovel, characterized in that the connection of the common part for the boom is switched so as to be used as a part other than the operating means for the boom. 5. The hydraulic drive system for a hydraulic shovel according to claim 1, wherein said first operating means comprises at least one operating lever, said switching means comprises a changeover switch, and said changeover switch comprises: A hydraulic drive device for a hydraulic shovel, wherein the hydraulic drive device is provided on any one of the operation levers.