JP3175868B2 - Backhoe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving unit disposed on a swivel base, a boom supported on the swivel base so as to be able to swing up and down, and a boom supported at the tip of the boom so as to be swingable. An interference prevention device that has a backhoe device including an arm and a bucket that is swingably supported on the distal end side of the arm, and that prevents the bucket from interfering with the driving unit when the backhoe device is operated. It relates to a backhoe whose area is set in front of the driving unit.

[0002]

2. Description of the Related Art A conventional backhoe is disclosed, for example, in Japanese Patent Application Laid-Open No. 4-333730.
That is, even if the bucket is operated so as to be closest to the driving unit, the trajectory C1 is set so that the tip of the bucket is located on the trajectory C1 separated by a predetermined distance from the driving unit, and this trajectory C1 becomes an interference prevention area. In some cases, the backhoe device can be operated while preventing the bucket from interfering with the driving unit.

[0003]

In the above-described conventional backhoe, when the bucket is moved as close as possible to the driving section so that the bucket can be easily seen, the boom is swung so as to rise, and the tip of the bucket is in an interference prevention area. It is necessary to adjust the bucket posture by swinging the bucket with respect to the arm so as to follow the arm, or swinging the arm with respect to the boom. For this reason, troubles such as a troublesome operation and a tendency for excavated earth and sand lifted by the bucket to easily fall down due to the adjustment of the posture of the bucket are likely to occur. An object of the present invention is to prevent a bucket from interfering with a driving unit and to operate a bucket.
The backhoe can be operated while approaching the
Another object of the present invention is to provide a backhoe that can raise a bucket along an interference prevention area only by raising and swinging a boom.

[0004]

The constitution, operation and effect of the invention according to claim 1 are as follows.

[Structure] A driving unit disposed on a swivel base, a boom supported by the swivel base so as to be swingable up and down, an arm supported by a tip end of the boom so as to be swingable, and the arm A backhoe device provided with a bucket that is swingably supported on the tip side of the driving unit, and an interference prevention area for preventing the bucket from interfering with the driving unit when the backhoe device is operated is provided in the driving unit. In the backhoe set forward, the interference prevention area is located away from the living space of the driving unit in front of the same and along the front surface of the living space; and a second interference prevention range is along an arc around the supporting point for the swivel base of the boom in a direction viewed along the pivot axis of the boom as well as located in the low level from the band, and further, Serial No.
2 The interference prevention area expands forward from the first interference prevention area.
It has a part to protrude .

[Operation] When the backhoe apparatus is operated in a state where the bucket is at the high level, the first interference prevention zone prevents the bucket from interfering with the driving section, and the bucket is at the low level. When operating the backhoe device with
The second interference prevention zone prevents the bucket from interfering with the driving unit. When the bucket is at a predetermined mounting position with respect to the arm in a state where the bucket is positioned at a low level, and the boom is lifted and swung with the arm at the predetermined mounting position with respect to the boom, the bucket turns. And rises along a second interference prevention area along an arc centered on the boom support point. And the second interference prevention area is before the first interference prevention area.
Since it has a part that bulges out to the side, the bucket can be swung with respect to the arm or the arm can be swung with respect to the boom to adjust the bucket attitude so that the bucket follows the interference prevention area. without carrying out, while the clarity from the driver section and along the bucket to the second interference prevention area, while not interfering with the operation unit, the first interference-proof
The stop area can be raised while being set as close as possible to the living space of the driving section .

[Effect] Accordingly, the backhoe apparatus can be operated while preventing the bucket from interfering with the driving unit, regardless of whether the bucket is at the high level or the low level. Moreover,
When the bucket is at the low level, the bucket rises so as not to interfere with the operation unit as close as possible to the operation unit only by raising and swinging the boom, and as described above, troubles such as excavated earth and sand falling from the bucket fall. It is possible to work advantageously while easily avoiding the problem, and to obtain a state in which simple operation and control only by raising the boom are enough. That percent
The first interference prevention zone as close as possible to the living space of the driving section
Set the bucket as close as possible to the driving unit for easy viewing
Work can be done advantageously.

The structure, operation and effect of the invention according to claim 2 are as follows.

[0009] [Structure] In the structure according to the first aspect of the present invention, the bucket can be moved to a rear side of the swivel base from the first interference prevention area at a lower level than the swivel base.

[Operation] In a state where the bucket is located in front of the driving unit, the bucket can be operated while preventing interference with the driving unit. It can be operated so as to reach the rear side from the interference prevention area.

[Effect] Although it is possible to prevent the bucket from interfering with the driving unit, the bucket can be pulled to the rear side of the first interference prevention area on the lower level side than the swivel base to perform excavation work over a wide range.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. (1) FIG. 6 shows the entire side surface of the backhoe. A traveling device 1 of rubber crawler type supports a dozer 20 and a swivel 2 above the dozer 20. A backhoe 3 is provided at the front of the swivel 2. I have. The backhoe device 3 is supported by the swivel base 2 so as to be able to swing up and down and is driven to swing up and down by a hydraulic cylinder 11. The arm 5 is oscillated back and forth by an arm 12, and the bucket 6 is swingably supported on the distal end side of the arm 5 and is slidably driven by a hydraulic cylinder 13. A hydraulic motor 14 is provided for driving the swivel 2 to turn.

The boom 4 in the backhoe 3 is shown in FIG.
As shown in the figure, the first boom part 4 is driven to swing up and down.
a, a second boom part 4b swingably connected around an axis P1 at a front end of the first boom part 4a, and a second boom part 4b.
A support bracket 4c is swingably connected around the axis P2 at the front end of the boom portion 4b, and the arm 5 is connected to the support bracket 4c. The link 4 is erected between the first boom portion 4a and the support bracket 4c to form a parallel quadruple link. The hydraulic cylinder 7 swings the second boom portion 4b, so that the arms 5 and The bucket 6 is configured so as to be able to move in parallel from side to side.

As shown in FIG. 5, a control valve 21 for the hydraulic cylinder 11 of the first boom portion 4a of the boom 4,
Hydraulic cylinder 7 of second boom portion 4b of boom 4
, A control valve 22 for the hydraulic cylinder 12 of the arm 5, a control valve 23 for the hydraulic cylinder 13 of the bucket 6, and a control valve 24 for the hydraulic motor 14 of the swivel 2. The control valves 21 to 25 are of a three-position switching type and of a pilot operation type, and the flow rate can be controlled by adjusting the opening based on the pilot pressure. An electromagnetic proportional pressure-reducing valve type pilot valve 3 for generating a pilot pressure for opening degree operation is provided to each of the control valves 21 to 25.
1a, 31b, 32a, 32b, 33a, 33b, 34
a, 34b, 35a, and 35b are provided.

As shown in FIGS. 4, 5, and 6, the swivel 2 is provided with a right operating lever 9 and a left operating lever 10.
The right and left operation levers 9 and 10 are freely operable back and forth and left and right, and are provided with a potentiometer 15 for detecting a front and rear operation position of the right operation lever 9 and a potentiometer 16 for detecting a left and right operation position. A potentiometer 17 for detecting the operation position of the operation lever 10 in the front-rear direction and a potentiometer 18 for detecting the operation position in the left-right direction are provided. Operation signals from the potentiometers 15 to 18 are input to the control device 19. An operation pedal 26 is provided at a lower portion on the front side of the swivel base 2, and an operation signal from the operation pedal 26 is input to the control device 19.

With the above configuration, when the right operating lever 9 is operated forward or backward, the pilot valves 31a, 3
1b generates a pilot pressure, the control valve 21 is operated on the lower side or the upper side of the first boom portion 4a, and when the control valve 21 is operated on the right or left side, the pilot valves 33a and 33b generate the pilot pressure based on the operation, and the control valve 23 is operated on the earth discharging side or the scraping side of the bucket 6. When the left operating lever 10 is operated forward or backward, the pilot valve 32
a and 32b generate pilot pressure, and the control valve 22 is operated to raise or scrape the arm 5, and when it is operated to the right or left, the pilot valves 34a and 34b generate pilot pressure based on this, and 24 is operated to the right turning side or the left turning side. When the operation pedal 26 is depressed to the right or left, the pilot valves 35a and 35b generate pilot pressure based on this, and the control valve 25 is operated to the right or left swing side of the second boom portion 4b.

In the above operation, each of the potentiometers 15 to 18 for the right and left operation levers 9 and 10 detects not only the operation direction of the right and left operation levers 9 and 10 but also the operation amount from the neutral position. I have. As a result, as the operation amounts of the right and left operation levers 9 and 10 increase, the pilot pressures of the pilot valves 31a to 34b increase and the control valve 21
-24 are operated to the large flow rate side. In other words, the larger the right and left operation levers 9 and 10 are operated, the more the hydraulic cylinder 11
13 and the hydraulic motor 14 are configured to operate at high speed.

(2) As shown in FIGS. 4 and 6, in the swivel base 2, a backhoe device 3 is disposed on the right side, and a driving operation comprising a driver's seat 28 and right and left operation levers 9 and 10 on the left side. The part 27 is arranged. Then, at the left and right center of the swivel 2,
A vertical partition plate 29 with a window for partitioning the backhoe device 3 and the operation unit 27 is provided, and a semicircular upper partition plate 30 along the outside of the swivel 2 is provided at the upper end of the vertical partition plate 29.
Has been fixed.

As shown in FIG. 2, in a range above a predetermined position D1 at a predetermined height from the ground G, the upper partition plate 3
The front first restraining surface A1 separated from the vertical partition plate 29 by a predetermined distance above the zero and a predetermined distance before the vertical partition plate 29 is set in the control device 19. In the range below the predetermined position D1, the front second restraining surface A2 bulging slightly forward from the front first restraining surface A1 is set in the control device 19. In this case, in a state where the bucket 6 is located at the position indicated by the solid line in FIG. 2, the first boom portion 4a (boom 4)
When the swinging operation is performed up and down around the support point 40 with the swivel 2, an arc-shaped trajectory in the side view drawn by the tip of the bucket 6 is defined as the front second restraint surface A2.

As shown in FIG. 4, a lateral restraint surface C which is separated from the side surface of the vertical partition plate 29 on the backhoe device 3 side by a predetermined distance to the right is set in the control device 19. In a range above a predetermined position D2 at a predetermined height from the ground G shown in FIG. 2, a surface separated from the first and second front restraint surfaces A1, A2 and the lateral restraint surface C by a predetermined distance forward or rightward. Is set, the plane of this space and the front first and second front restraint planes A
1, A2, and the lateral restraint surface C are set in the control device 19 as a front restraint region B1 and a lateral restraint region B2.
The front first and second front restraint surfaces A1 and A2, the lateral restraint surface C, and the front and side restraint areas B1 and B2 as described above are set with respect to the turntable 2, and the turntable 2 turns. With this, it moves together with the swivel 2.

(3) Next, a description will be given of the detection of the attitude of each part of the backhoe device 3 and its correction. As shown in FIGS. 5 and 6, a potentiometer 36 that outputs a detection value corresponding to the vertical angle of the first boom portion 4a (boom 4) with respect to the swivel 2 and the second boom portion 4b with respect to the first boom portion 4a. A potentiometer 37 that outputs a detection value corresponding to the left and right angle,
There are provided a potentiometer 38 for outputting a detection value in accordance with the front-rear angle of the arm 5 with respect to the support bracket 4c, and a potentiometer 39 for outputting a detection value in accordance with the front-rear angle of the bucket 6 with respect to the arm 5,
The detection signals from the potentiometers 36 to 39 are input to the control device 19. In the above state, the vertical angle of the first boom portion 4a, the horizontal angle of the second boom portion 4b, the front-back angle of the arm 5, and the front-back angle of the bucket 6,
Each of the potentiometers 36 to 3 is adjusted so that the detected value output from each of the potentiometers 36 to 39 exactly matches.
9 should be attached, but it is assumed that these relations are slightly shifted due to a slight attachment error or the like.

In this case, the following correction operation is performed before starting the work. As shown in FIG. 1, first, a gauge (not shown) for the first boom portion 4a is prepared, and the vertical angle of the first boom portion 4a with respect to the swivel 2 is 90 degrees along the gauge. Then, the first boom portion 4a is slowly raised or lowered to accurately stop at 90 degrees (step S1). When the operator presses an operation button (not shown) in this state, the detection value of the potentiometer 36 in FIG. 6 at this time is stored as a reference detection value (step S2). Then, the first boom portion 4a
The detected value of the potentiometer 36 already set in the control device 19 is compared with the reference detected value (step S3), and the difference between this detected value and the reference detected value is corrected. Is set as a value (step S
4) This is taken into the control device 19 as a correction value for the first boom portion 4a (step S5).

When the correction operation of the first boom part 4a is completed as described above, next, the same correction operation is performed on the second boom part 4b, the arm 5, and the bucket 6. That is, a gauge (not shown) for the second boom portion 4a, a gauge (not shown) for the arm 5, and a gauge (not shown) for the bucket 6 are prepared, and the second gauge is arranged along the gauge.
Slowly operate the boom portion 4b, arm 5 and bucket 6 to stop accurately at an angle along the gauge (eg, the second boom portion 4b is linear with the first boom portion 4a, so that the arm 5 is The angle between the second boom portion 4b and the bucket 6 is set to 90 degrees with respect to the second boom portion 4b.
So that it is at a 90 degree angle to.

In this state, when the operator presses the operation button, the potentiometers 37 and 3 in FIG.
The detection values of 8, 39 are stored as reference detection values. Then, the second boom portion 4b, the arm 5, and the bucket 6
The control device 1 corresponds to the angle along the gauge of
Potentiometers 37 and 3 already set in 9
The detected values 8 and 39 are compared with the reference detected value, and the difference between the detected value and the reference detected value is set as a correction value, which is the correction value for the second boom portion 4b, the arm 5, and the bucket 6. Is taken in the control device 19.

(4) Next, the control of the backhoe device 3 for the first and second front restraint surfaces A1, A2 and the front restraint area B1 will be described. In the control device 19, the detection values (the vertical angle of the first boom portion 4a, the left and right angle of the second boom portion 4b, the front and rear angles of the arm 5 and the bucket 6) from the potentiometers 36 to 39 in FIG. ), The correction values for the first and second boom portions 4a and 4b, the arm 5, and the bucket 6 which have already been calculated are added, and these and the first boom portion 4 are added.
a, the position of the tip of the bucket 6 and the position of the bottom of the bucket 6 are constantly calculated based on the lengths of the second boom portion 4b, the arm 5, and the bucket 6. Then, the moving direction and moving speed of the tip and the bottom of the bucket 6 are calculated by differentiating the value obtained by adding the correction value to the detection values of the potentiometers 36 to 39.

As a result, as shown in FIG.
Is located in front of the swivel 2, when the tip of the bucket 6 is closer to the swivel 2 than at the bottom, when the tip of the bucket 6 enters the front restraint region B <b> 1, the pilot valves 31 a to 32 b, 35 a, The operating speed of the hydraulic cylinders 11 and 7 of the first and second boom portions 4a and 4b and the hydraulic cylinder 12 of the arm 5 is changed regardless of the operation of the right and left operation levers 9 and 10 and the operation pedal 26 when the 35b is operated. Deceleration operation is performed. In this case, as the leading end of the bucket 6 enters the front restraint area B1 and approaches the front first restraint surface A1 or the front second restraint surface A2, the hydraulic cylinders 11, 7, and 12 are greatly decelerated. Conversely, the tip of the bucket 6 is
In the direction away from the restraining surface A1 or the front second restraining surface A2, the first
When the second boom portions 4a and 4b and the arm 5 are operated, the operating speeds of the hydraulic cylinders 11, 7, and 12 are increased in the front restraint area B1, contrary to the aforementioned deceleration. When the vehicle exits the front restraint area B1, the operation is returned to the original speed.

Then, the tip of the bucket 6 is positioned at the first position in FIG.
It is assumed that the check surface A1 has been reached. In this case, regardless of whether the arm 5 is operated on the scraping side or the first boom part 4a is operated on the ascending side, the second boom part 4b is moved on the left swing side (the driving unit 2).
7), the tip of the bucket 6 enters the driving unit 27 side beyond the front first restraint surface A1. Therefore,
With the tip of the bucket 6 reaching the front first restraint surface A1,
Even if the left operating lever 10 is used to move the arm 5 to the scraping side, the right operating lever 9 is used to raise the boom 4, and the operation pedal 26 is used to operate the second boom portion 4 b to the left swing side, the pilot valves 31 a to 32 b , 35a, 35b disappear, and the hydraulic cylinders 11, 7, 12 are stopped by the control valves 21, 22, 25. Conversely, bucket 6
When the tip of the bucket 6 reaches the front first restraining surface A1, the raising operation of the arm 5, the lowering operation of the first boom portion 4a, and the right swing operation of the second boom portion 4b are performed by the front end of the bucket 6 being the first first.
Since the operation is in the direction away from the check surface A1, these operations can be performed without any trouble.

The operation of the bucket 6 by the hydraulic cylinder 13 in a state where the tip of the bucket 6 reaches the front first restraint surface A1 is configured under the following conditions. That is, as shown in FIG.
If the attitude of the bucket 6 is located within the set range F across the attitude H orthogonal to the front first restraint surface A1 in a state where the tip of the bucket 6 is located on the front first restraint surface A1, this set range The vertical swinging operation of the bucket 6 by the hydraulic cylinder 13 can be performed in F. Then, in a state where the bucket 6 is in the upward posture beyond the set range F and the tip thereof is located on the front first restraint surface A1, when the bucket 6 is swung downward, the tip of the bucket 6 becomes the first first restraint. In this case, the bucket 6 can only be pivoted upward from the current state, since it largely enters the driving section 27 beyond the surface A1. Conversely, in a state where the bucket 6 is in a downward position beyond the set range F and the tip thereof is located on the front first restraint surface A1, when the bucket 6 is swung upward, the tip of the bucket 6 becomes the first first restraint. In this case, the bucket 6 can only be operated to swing downward from the current state because the bucket 6 largely enters the driving unit 27 beyond the surface A1.

Next, it is assumed that the tip of the bucket 6 has reached the front second restraining surface A2 in FIG. In this case, regardless of whether the arm 5 is operated to the scraping side or the second boom portion 4b is operated to the left swinging side (the driving section 27 side), the tip of the bucket 6 exceeds the front second restraining surface A2. It enters the operation unit 27 side. However, in a state where the bucket 6 is positioned at the position indicated by the solid line in FIG. 2, when the first boom part 4 a (boom 4) is vertically swung around the support point 40 with the swivel 2,
An arc-shaped trajectory in a side view drawn by the tip of the bucket 6 is defined as a front second restraint surface A2. Thus, even if the first boom portion 4a is raised and lowered with the tip of the bucket 6 reaching the front second restraining surface A2, the tip of the bucket 6 only moves on the front second restraining surface A2. The tip of the bucket 6 does not enter the driving section 27 side beyond the front second restraint surface A2.

Accordingly, with the tip of the bucket 6 reaching the front second restraining surface A2, the arm 5 is squeezed by the left operating lever 10 and the second boom portion 4b is swung by the operating pedal 26 to the left swinging side. The pilot valves 32a, 3
The pilot pressures of 2b, 35a and 35b disappear, and the control valves 22 and 25 stop the operation of the hydraulic cylinders 7 and 12. However, the first boom part 4 by the right operating lever 9
The raising and lowering operations of a can be performed without any trouble. When the tip of the bucket 6 reaches the front second restraining surface A2, the raising operation of the arm 5 and the right swinging operation of the second boom portion 4b move the tip of the bucket 6 away from the front second restraining surface A2. Since the operation is in the direction, these operations can be performed without any trouble. or,
With the tip of the bucket 6 reaching the front second restraint surface A2,
The operation of the bucket 6 by the hydraulic cylinder 13 is possible under the conditions as described above.

(5) Next, the control of the backhoe device 3 for the lateral restraint surface C and the lateral restraint area B2 will be described. In the control device 19, the potentiometers 36 to 39 shown in FIG.
, The correction values for the first and second boom portions 4a and 4b, the arm 5, and the bucket 6 already calculated in the previous section (3) are added, and these are added to the first and second boom portions 4a and 4a.
The position of the left side surface of the bucket 6 is constantly calculated based on the lengths of the boom portion 4b, the arm 5, and the bucket 6.
Then, the moving direction and the moving speed of the left lateral side of the bucket 6 are calculated by differentiating the value obtained by adding the correction value to the detection values of the potentiometers 36 to 39.

When the bucket 6 is located on the right side of the operating section 27 as shown by the solid line in FIG. 4, the second boom portion 4b is swung by the hydraulic cylinder 7 toward the operating section 27, and 6 enters the lateral restraint area B2, the pilot valves 35a and 35b are operated, and the second boom portion 4b is operated regardless of the operation of the operation pedal 26.
The operation speed of the hydraulic cylinder 7 is decelerated. In this case, the more the left lateral side of the bucket 6 enters the lateral restraint area B2 and approaches the lateral restraint surface C, the greater the deceleration operation is performed.
Conversely, when the second boom portion 4b is operated in a direction in which the left lateral side of the bucket 6 is separated from the lateral restraint surface C, the second boom portion 4b is moved in the lateral restraint region B2 in the opposite manner to the aforementioned deceleration. The operating speed of the hydraulic cylinder 7 is increased, and is returned to the original speed when the hydraulic cylinder 7 moves out of the lateral restraint area B2.
When the left lateral side of the bucket 6 reaches the lateral restraint surface C and is about to be operated to the operating section 27 side even slightly beyond the lateral restraint surface C, the pilot valves 35a, 35b
, And the control valve 25 stops the hydraulic cylinder 7 of the second boom portion 4b.

(6) Next, control of the backhoe device 3 in a region below the predetermined position D2 will be described. As described above, in the region above the predetermined position D2 shown in FIG. 2, the front restraint region B1 and the lateral restraint region B2 are set with respect to the first and second front restraint surfaces A1 and A2 and the lateral restraint surface C. However, this is not set in the area below the predetermined position D2. Therefore, until the tip of the bucket 6 reaches the front second restraining surface A2, the backhoe device 3 is driven at a speed based on the operation of the right and left operation levers 9, 10 and the operation pedal 26.
Hydraulic cylinders 11, 12, and 7 are operated. When the tip of the bucket 6 reaches the front second restraining surface A2, the operation of the arm 5 on the squeezing side and the operation of the second boom portion 4b on the left swinging side cannot be performed, but the lifting of the first boom portion 4a and The descending operation can be performed. The operation of the bucket 6 is also possible under the conditions as described in the above (4).

That is, the vertical partition plate 29 and the upper partition plate 30
The driving unit 27 is provided with a living space surrounded by A first interference portion of the front first restraining surface A1 that is located away from the living space of the driving unit 27 in front of the living space by the restraining surface portion that is farther forward than the vertical partition plate 29 and is along the front surface of the living space. The prevention zone Z1 is located at a lower level than the first interference prevention zone Z1 by the front second restraint surface A2 , and is expanded forward of the first interference prevention zone Z1.
A second interference prevention zone Z2 having a deflected portion is formed, and an interference prevention zone having the second interference prevention zone Z2 and the first interference prevention zone Z1 is set in front of the operation unit 27. Bucket 6
Can be operated while preventing the backhoe device 3 from interfering with the driving unit 27.

When the first boom portion 4a (boom 4) is vertically swung around a support point 40 with the swivel base 2, an arc-shaped trajectory drawn by the tip of the bucket 6 in a side view is drawn to the front second restraint surface. A2. For this reason, the second interference prevention zone Z2 is provided at the support point 40 when viewed in a direction along the pivot axis of the boom 4.
And at a lower level than the swivel base 2 and at a position behind the swivel base with respect to the first interference prevention zone Z1. As a result, on the lower level side than the turntable 2, the bucket 6
The backhoe device 3 can be operated so as to move to the rear side of the swivel table from 1 and the tip of the bucket 6 rises along the second interference prevention zone Z2 simply by swinging the boom 4 up. Can be lifted up and down.

[Alternative Embodiment] In the above-described embodiment, the operating positions of the right and left operating levers 9, 10 and the operating pedal 26 are electrically detected by potentiometers 15 to 18, and the pilot valve of the electromagnetic proportional pressure reducing valve type is used. 31a to 35b, the pilot operated control valve 21
Although the present invention is applied to this type, the present invention may be applied to a backhoe having the following configuration. That is, the operation positions of the right and left operation levers 9, 10 and the operation pedal 26 are electrically detected by the potentiometers 15 to 18 without the provision of the above-described pilot valves 31a to 35b of the electromagnetic proportional pressure reducing valve type. A type in which the control valves 21 to 25 of the electromagnetic proportional pressure reducing valve type are operated based on the detected value. Also, without using the potentiometers 15 to 18 described above, the right and left operation levers 9 and 10, the operation pedal 2
6, a pilot valve (not shown) is mechanically operated directly, and the control valves 21 to 25 are switched by the pilot pressure from the pilot valve.

Incidentally, reference numerals are written in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configuration of the attached drawings by the entry.

[Brief description of the drawings]

FIG. 1 is a diagram showing a flow of an operation for setting a correction value for a potentiometer.

FIG. 2 is a schematic side view of a backhoe showing front first and second check surfaces and a front check area.

FIG. 3 is a side view in a state where the tip of the bucket has reached the front first and second front restraint surfaces.

FIG. 4 is a schematic plan view of a backhoe showing first and second front restraint surfaces, a front restraint region, a lateral restraint surface, and a lateral restraint region.

FIG. 5 shows each hydraulic cylinder, control valve,
Diagram showing the relationship between the pilot valve, right and left operating levers, etc.

FIG. 6 is an overall side view of the backhoe.

[Explanation of symbols]

 2 Swivel base 3 Backhoe device 4 Boom 5 Arm 6 Bucket 7, 11, 12, 13 Hydraulic cylinder 27 Operating unit 40 Support point Z1 First interference prevention area Z2 Second interference prevention area

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-333730 (JP, A) JP-A-4-272333 (JP, A) JP-A-59-65131 (JP, A) JP-A-5-131 280074 (JP, A) Japanese Utility Model Hei 2-80165 (JP, U)

Claims (2)

(57) [Claims] An operating unit (2) arranged on a swivel (2).
7) a boom (4) supported on the swivel table (2) so as to be swingable up and down; an arm (5) supported on the tip end of the boom (4) so as to be swingable; (5)
A backhoe device (3) provided with a bucket (6) that is swingably supported on the tip side of the device.
Bucket (6) when operating the backhoe device (3)
Is a backhoe in which an interference prevention area for preventing interference with the driving section (27) is set in front of the driving section (27), and the interference prevention area is provided from the living space of the driving section (27). A first interference prevention zone (Z1) that is located at a distance away from the front and along the front surface of the living space, and a swing axis of the boom (4) that is located at a lower level than the first interference prevention zone (Z1). a second interference prevention area lying along the arc around the supporting point of the boom (40) of the swivel base in the direction viewed along the core (2) and (Z2), further, the second
The interference prevention zone (Z2) is different from the first interference prevention zone (Z1).
A backhoe with a part that bulges forward . 2. A structure in which the bucket (6) can be operated to move to a rear side of the swivel platform from the first interference prevention zone (Z1) at a lower level than the swivel platform (2). The described backhoe.