JPH1136359A - Back hoe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a back hoe which easily executes beyond mistake a straight excavation and a straight leveling that the front end (bucket) of an arm is reciprocated almost along a specified straight track. SOLUTION: When one operation lever 9 is driven to the rising side of a boom 4 in the state that the other operation lever 10 is driven to the scraping side (discharging side of soil) of an arm 5, the first control valve of the boom 4 is driven automatically from the rising side to the lowering side to correct the operation position, on the basis of the detected value of the angle sensors 36, 38 of the boom 4 and the arm 5 so that the front end of the arm 5 transfers almost along a specified straight track D1. And the second control valve of the arm 5 is automatically corrected in the scraping side (discharging side of soil).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backhoe for civil engineering construction for performing excavation work.

[0002]

2. Description of the Related Art A backhoe generally includes a pair of operation levers which are manually operated to operate a backhoe device and a swivel table, and one of the operation levers is used to operate the arm on the scraping side and the earth discharging side. Then, the other operation lever is configured to perform the operation of raising and lowering the boom.

[0003]

When excavation work is performed with a backhoe, for example, the tip (bucket 6) of the arm 5 is moved substantially linearly as shown in FIGS. Excavation Straight excavation may be performed. In such a straight excavation, for example, as shown in FIGS. 8A and 8B, when the tip (bucket 6) of the arm 5 is approached to the turntable 2 from a position away from the arm 5, the arm 5 is operated to the scraping side. At the same time, it is necessary to operate the boom 4 upward, and to operate the boom 4 downward again, for example, as shown in FIGS. This is because the arm 5 is operated to swing back and forth with the tip of the boom 4 as a fulcrum. When the arm 5 is operated to the scraping side while the boom 4 is stopped, the tip (bucket 6) of the arm 5 moves in an arc locus. This is because they move along.

However, since the operator who operates the operation lever is at the turntable and is away from the bucket, and it is difficult to accurately observe the position of the bucket, the operator operates the arm by using one of the operation levers so as to scrape the arm. However, it is often difficult to accurately operate the boom upward and downward by the other operation lever so as to match the operation of the arm. An object of the present invention is to provide a backhoe so that the above-described straight excavation can be performed accurately and without misunderstanding by an operator.

[0005]

[Means for Solving the Problems]

[I] In a state where the tip (bucket) of the arm is located at a position away from the turntable (a state where the tip (bucket) of the arm is located at a position close to the turntable), for example, an operator of the turntable One of the operating levers is operated on the scraping side (discharge side) of the arm, and the second control valve of the arm is operated on the scraping side (discharge side). It is assumed that the user operates the first control valve of the boom to move up to move the tip (bucket) of the arm substantially linearly.

In this case, according to the features of the first aspect, the tip of the arm (bucket) is determined by the detection value of the angle sensor for detecting the angle of the boom with respect to the swivel table and the detection value of the angle sensor for detecting the angle of the arm with respect to the boom. ) Is grasped, and based on this, the operation position of the first or second control valve with respect to one or the other operation lever is automatically corrected on the boom raising side or the arm scraping side (discharge side). Then, the tip (bucket) of the arm moves substantially along a predetermined linear trajectory.

Next, when the tip (bucket) of the arm reaches a set position of a predetermined linear trajectory (for example, a position where the arm is orthogonal to the predetermined linear trajectory), the other operating lever is raised by the boom. Regardless of this operation, the first control valve of the boom is automatically operated to the descending side. As a result, the operation position of the first or second control valve with respect to one or the other operation lever is automatically corrected on the descending side of the boom or the scraping side (discharge side) of the arm, and the tip of the arm (bucket) ) Moves substantially along a predetermined linear locus.

As described above, according to the first aspect of the present invention, the operator of the swivel base only operates the one and the other operation levers on the scraping side (discharge side) of the arm and the raising side of the boom. Then, while the first control valve of the boom is automatically operated from the ascending side to the descending side, while the second control valve of the arm is operated to the scraping side (discharge side), the first or second boom is controlled. The operation position of the control valve is automatically corrected, and the tip (bucket) of the arm moves substantially along a predetermined linear trajectory.
Accordingly, by operating one of the operating levers to the scraping side and the earth discharging side of the arm while the other operating lever is operated to the rising side of the boom, the tip (bucket) of the arm is obtained.
Can be reciprocated substantially along a predetermined linear trajectory.

[II] As described in the preceding item [I], the operation position of the first or second control valve with respect to one or the other operation lever is automatically corrected (when the first control valve of the boom is moved from the rising side). When the arm tip (bucket) moves substantially along a predetermined straight line trajectory (operated automatically on the descending side), the first or second operation lever is moved to the operation position corresponding to one or the other operation lever. The control valve is not always operated,
The first or second control valve may be operated at an operation position slightly deviated from the operation position corresponding to one or the other operation lever (when the first control valve of the boom is operated to the opposite descending side). May be present). Therefore, the operator of the turntable grasps a state in which the operation position of the first or second control valve is automatically corrected (a state in which the first control valve of the boom is operated on the opposite downward side). If not, as described in the preceding section [I], the first or second operation lever for one or the other
When the operating position of the control valve is automatically corrected (when the first control valve of the boom is operated to the reverse descending side), the arm and the boom do not operate as expected. The operator of the swivel base may misunderstand.

According to the first aspect of the present invention, when the operator of the revolving base operates one of the operating levers on the scraping side and operates the other operating lever on the rising side of the boom, the above item [I] As described in the above, the operating position of the first or second control valve is automatically corrected, and the tip (bucket) of the arm moves substantially along a predetermined linear trajectory. As a result, as described above, the operator of the turntable operates the one and the other operation levers to move the tip (bucket) of the arm substantially along a predetermined linear trajectory. The operation position of the first or the second control valve is automatically corrected as described in the preceding section [I] based on the clear intention of the person (the first control valve of the boom moves to the opposite descending side). Even if the first or second control valve is operated at an operation position slightly deviated from the operation position corresponding to one or the other operation lever (because the first control valve of the boom is on the opposite descending side). Is not misunderstood that the turntable operator is in an abnormal state.

[III] According to the feature of the second aspect, similar to the case of the first aspect, it has the "action" described in the above-mentioned [I], and in addition to this, has the following "action". ing. In the backhoe, the first control valve of the boom and the second control valve of the arm are configured to be pilot-operated, and include a pilot valve that generates a pilot pressure in accordance with the operation position of the pair of operation levers. There is a pilot operation type backhoe configured to generate a pilot pressure by operating an operation lever and operate the first and second control valves by the pilot pressure.

According to a second aspect of the present invention, in the above-described pilot operated backhoe, a pilot oil passage connecting one and the other operation levers (pilot valves) to the first and second control valves is provided. If the first, second, third and fourth correction means for changing the pressure are interposed, the pilot pressure is automatically changed in response to one or the other operation lever as described in [I] above. Then, the operating position of the first or second control valve is automatically corrected (the first control valve of the boom is operated to the opposite descending side), and the tip (bucket) of the arm substantially follows a predetermined linear trajectory. Moving along. In this case, according to the features of claim 2, the pilot pressure can be adjusted without particularly changing the configuration of the one and other operation levers, the pilot valve, the first and second control valves of the pilot operation type, and the relationship between the respective parts. 1st, 2nd, 3rd, 4th to change
It is only necessary to add a correction means.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

(1) FIG. 1 shows the entire side surface of the backhoe. A turning table 2 is supported by a rubber crawler type traveling device 1, and the turning table 2 is provided with a backhoe device 3. The backhoe device 3 is operated to swing up and down by a first hydraulic cylinder 11, an arm 5 operated to swing back and forth by a second hydraulic cylinder 12, and operated to swing back and forth by a third hydraulic cylinder 13. It is provided with a bucket 6.

The boom 4 of the backhoe device 3 has a first boom portion 4a which is vertically swung and a first boom portion 4a.
The second boom portion 4b is swingably connected around the axis P1 at the front end of the second boom, and the support bracket 4c is swingably connected around the axis P2 at the front end of the second boom portion 4b. The arm 5 is connected to the support bracket 4c. A link 4 is erected between the first boom portion 4a and the support bracket 4c to form a parallel quadruple link.
By swinging b, the arm 5 and the bucket 6 are moved left and right in parallel.

As shown in FIGS. 1 and 5, in the swivel 2, a backhoe device 3 is disposed on the right side, and a driver's seat 14 and a driving unit 15 including right and left operation levers 9 and 10 are disposed on the left side. Have been. At the left and right center of the swivel base 2, a vertical partition plate 16 with a window is provided to partition the backhoe device 3 and the operation unit 15, and an upper partition plate 17 along the outside of the swivel base 2 is provided at the upper end of the vertical partition plate 16. Has been fixed.

(2) Next, an operation structure of the hydraulic circuit structure, the backhoe device 3, the swivel 2 and the like will be described. As shown in FIG. 2, the first control valve 21 of the first hydraulic cylinder 11 of the first boom portion 4a (boom 4), the second control valve 22 of the second hydraulic cylinder 12 of the arm 5, and the third hydraulic pressure of the bucket 6 The third control valve 23 of the cylinder 13, the fourth control valve 24 of the swing motor 18 of the swivel 2, the fifth control valve 25 of the fourth hydraulic cylinder 7 of the second boom portion 4 b, and the control valve 26 of the right traveling device 1 , The control valve 27 of the left traveling device 1, the control valve 28 of the service port (not shown), and the dozer 1 shown in FIG.
A control valve 29 of a hydraulic cylinder 50 for raising and lowering the cylinder 9 is provided, and hydraulic oil from a pump 20 is supplied to the first to fifth control valves 21 to 25 and the control valves 26 to 29.

The first control valve 21 of the first boom portion 4a, the second control valve 22 of the arm 5, and the third control valve 2 of the bucket 6
3. Fourth control valve 24 of swivel 2 and second boom portion 4b
The fifth control valve 25 is of a pilot-operated type using a pilot pressure and is of a neutral return type. Control valves 26 and 27 of the right and left traveling devices 1, a control valve 28 of the service port,
The control valve 29 of the dozer 19 is configured to be a mechanically operated neutral return type operated by an operation lever (not shown).

As shown in FIG. 3, the right operating lever 9 is configured to be operable forward, backward, left and right, and a pilot valve 31a for generating a pilot pressure by a rear operation of the right operating lever 9;
A pilot valve 31b that generates pilot pressure by operating the right operating lever 9 in front, a pilot valve 33a that generates pilot pressure by operating the right operating lever 9 to the right, and a pilot that generates pilot pressure by operating the right operating lever 9 to the left. A valve 33b is provided.

Similarly, the left operating lever 10 is also configured to be operable in the front, rear, left and right directions. The pilot valve 32a generates a pilot pressure by the rear operation of the left operating lever 10, and the pilot pressure is generated by the front operation of the left operating lever 10. A pilot valve 32b which generates a pilot pressure by operating the left operating lever 10 to the right, and a pilot valve 34b which generates pilot pressure by operating the left operating lever 10 to the left are provided.

As shown in FIGS. 5 and 3, an operation pedal 39 is provided which can be operated to be depressed right and left.
9 is provided with a pilot valve 35a for generating a pilot pressure by operating the left pedal and a pilot valve 35b for generating a pilot pressure by operating the operating pedal 39 right. A pilot pump 30 for supplying pilot pressure to the pilot valves 31a to 35b is provided.

As shown in FIGS. 2 and 3, the pilot valves 31a and 31b of the right operating lever 9 and the first boom portion 4a
Of the first control valve 21 and the pilot valve 33 of the right operating lever 9
a, 33b and the third control valve 23 of the bucket 6 are connected via pilot oil passages 51a, 51b, 53a, 53b. The pilot valve 32a of the left operation lever 10,
32b, the second control valve 22 of the arm 5, the left operating lever 10
And the fourth control valve 24 of the swivel 2 are connected to the pilot oil passages 52a, 52b, 54a, 5
4b. The pilot valves 35a and 35b of the operation pedal 39 and the fifth control valve 25 of the second boom portion 4b are connected via pilot oil passages 55a and 55b.

When the right operation lever 9 is operated backward by the above structure, the pilot pressure from the pilot valve 31a causes
The first control valve 21 is operated on the ascending side of the first boom portion 4a (extending side of the first hydraulic cylinder 11), and the right operating lever 9 is operated.
Is operated by the pilot pressure from the pilot valve 31b, the first control valve 21 is operated on the lowering side of the first boom portion 4a (the contracting side of the first hydraulic cylinder 11). When the right operating lever 9 is operated to the right, the third control valve 23 is operated to the discharging side of the bucket 6 (the contracting side of the third hydraulic cylinder 13) by the pilot pressure from the pilot valve 33a, and the right operating lever 9 is operated to the left. Then, the third control valve 23 is operated to the squeezing side of the bucket 6 (the extending side of the third hydraulic cylinder 13) by the pilot pressure from the pilot valve 33b.

When the left operation lever 10 is operated backward, the second control valve 22 is actuated by the pilot pressure from the pilot valve 32a.
Is operated on the scraping side of the arm 5 (extended side of the second hydraulic cylinder 12) and when the left operating lever 10 is operated forward, the pilot pressure from the pilot valve 32b causes the second control valve 22 to move to the earth discharging side of the arm 5. (The contraction side of the second hydraulic cylinder 12). When the left operating lever 10 is operated to the right, the fourth control valve 24 is operated to the right turning side of the swivel 2 by the pilot pressure from the pilot valve 34a, and when the left operating lever 10 is operated to the left, the pilot pressure from the pilot valve 34b is operated. Thereby, the fourth control valve 24 is operated to the left turning side of the swivel 2.

When the operation pedal 39 is depressed to the left, the fifth control valve 25 of the second boom portion 4b is operated to the left swing side (the extension side of the fourth hydraulic cylinder 7) by the pilot pressure from the pilot valve 35a. When the operation pedal 39 is depressed to the right, the pilot pressure from the pilot valve 35b causes
The fifth control valve 25 of the second boom portion 4b is moved to the right swing side (fifth
(The contraction side of the hydraulic cylinder 7).

As the right and left operation levers 9 and 10 and the operation pedal 39 are largely operated from the neutral position, the pilot valve 3
The pilot pressures 1a to 35b are configured to increase. Thereby, the right and left operation levers 9, 10,
The larger the operation pedal 39 is operated from the neutral position, the larger the pilot pressure of the pilot valves 31a to 35b, and the first to fifth control valves 21 to 25 are operated to the larger flow rate side. That is, as the right and left operation levers 9 and 10 and the operation pedal 39 are operated larger, the first to fourth hydraulic cylinders 11 and 1 are increased.
2, 13, 7 and the turning motor 18 operate at high speed.

(3) Next, the front restraint surface A1, the lateral restraint surface A2, and the like set for the swivel 2 will be described. FIG.
As shown in FIG. 5, a front restraint surface A <b> 1 separated by a predetermined distance in front of the front edge of the vertical partition plate 16 and the front edge of the upper partition plate 17, and rightward from the lateral side of the vertical partition plate 16. The lateral restraint surface A2 which is separated from the control device 40 by a predetermined distance
See).

In this case, when the bucket pin 6a connecting the bucket 6 to the tip of the arm 5 is located on the front restraint surface A1, the bucket 6 is operated to swing so as to be closest to the driving unit 15 side. Also, the front restraint surface A is positioned so that the tip of the bucket 6 is located on a locus C1 separated by a predetermined distance from the front edge of the vertical partition 16 and the front edge of the upper partition 17.
1 is set. Bucket pin 6a is on the side A2
, The lateral restraint surface A2 is set such that the left lateral side surface of the bucket 6 is located on a locus C2 separated from the vertical partition plate 16 by a predetermined distance.

A surface which is separated from the front and side restraint surfaces A1 and A2 by a predetermined distance to the front or right is set, and the space between the space and the front and side restraint surfaces A1 and A2 is the front restraint region B1 and the front restraint region B1. The lateral restraint region B2 is set in the control device 40. The front and side restraint surfaces A1 and A2 and the front and side restraint areas B1 and B2 as described above are set with respect to the swivel base 2 and, together with the swivel base 2 as the swivel base 2 turns. It is something that moves to.

As shown in FIGS. 1 and 4, a connecting portion between the swivel 2 and the first boom portion 4a has a first
An angle sensor 36 for detecting the angle of the boom portion 4a is provided, and an angle sensor 37 for detecting the angle of the second boom portion 4b with respect to the first boom portion 4a is provided at a connection between the first and second boom portions 4a and 4b. Provided. An angle sensor 38 for detecting an angle of the arm 5 with respect to the second boom portion 4b is provided at a connecting portion between the support bracket 4c and the arm 5.

The angle sensors 36, 37, 3 as described above
8 is input to the control device 40, and based on the detection values of the angle sensors 36, 37, and 38, the front and side restraint surfaces A1 and A2, the front and side
The position of the bucket pin 6a with respect to 1 and B2 is detected by the control device 40.

As shown in FIG. 3, the pilot oil passages 51a, 51b connecting the pilot valves 31a, 31b of the right operating lever 9 and the first control valve 21 of the first boom portion 4a,
A pilot oil passage 52 connecting the pilot valves 32a, 32b of the left operation lever 10 and the second control valve 22 of the arm 5
a, 52b and the pilot valve 35 of the operation pedal 39
a and a pilot oil passage 55a connecting the fifth control valve 25 of the second boom portion 4b (a pilot oil passage 55a for operating the fifth control valve 25 of the second boom portion 4b to the left swing side). Electromagnetically operated pressure control valves 41a, 41b, 42
a, 42b and 43 are provided.

Therefore, the pressure control valves 41a, 41b, 42
a, 42b, 43 to reduce the pilot pressure (the maximum pressure is the right and left operating levers 9, 10 and the operating pedal 3).
9), right and left operating levers 9, 1
0, regardless of the operation position of the operation pedal 39, the opening degree of the first control valve 21 of the first boom portion 4a on the ascending side and the descending side,
The opening degree of the second control valve 22 of the arm 5 on the scraping side and the earth discharging side, and the opening degree of the fifth control valve 25 of the second boom portion 4b on the left swing side can be arbitrarily changed. The pressure control valves 41a, 41b,
By setting the pilot pressure to zero by 42a, 42b and 43, the first hydraulic cylinder 11 of the first boom portion 4a and the arm 5 of the arm 5 are independent of the operation positions of the right and left operation levers 9 and 10 and the operation pedal 39. Second hydraulic cylinder 1
2. The fourth hydraulic cylinder 7 of the second boom portion 4b can be stopped.

(4) When the bucket pin 6a is to be operated toward the operation section 15 beyond the front restraint surface A1, the operation is prevented from being restrained. Next, FIG. A description will be given based on FIG. Control device 4
At 0, the angle of the first boom portion 4a, the angle of the second boom portion 4b, the angle of the arm 5 and the angles of the first boom portion 4a, the second boom portion 4b, and the arm 5 based on the detection values of the angle sensors 36, 37, 38. With each length, the position of the bucket pin 6a is constantly detected (Step S).
1).

Thus, when the bucket pin 6a enters the front restraint area B1 shown in FIGS. 4 and 5 (step S2), the right operating lever 9 is operated backward to operate the first boom portion 4 (step S2).
When "a" is operated upward (step S3), the bucket pin 6a enters a state of approaching the front restraint surface A1. In this state, the pilot pressure of the pilot valve 31a is reduced by the pressure control valve 41a shown in FIG.
a (the extension speed of the first hydraulic cylinder 11) is decelerated, and the bucket pin 6a
As the vehicle approaches 1, the ascending speed of the first boom portion 4 a (the extension speed of the first hydraulic cylinder 11) is more greatly reduced (step S <b> 6). Bucket pin 6a is the front restraint surface A1
(Step S4), the pressure control valve 4 shown in FIG.
1a, the pilot pressure of the pilot valve 31a is set to zero, the first control valve 21 is operated to the neutral position irrespective of the operation position of the right operation lever 9 after the operation, and the first boom portion 4a (the first hydraulic cylinder 11) stops (step S5).

Conversely, when the right operating lever 9 is operated forward and the first boom portion 4a is operated downward (step S3).
Since the bucket pin 6a is separated from the front restraint surface A1, even if the bucket pin 6a is located in the front restraint surface A1 and the front restraint area B1, the operation position of the front operation of the right operation lever 9 is not related to this. (Step S7) (the pressure control valve 41b of the pilot valve 31b of the right operating lever 9 shown in FIG. 3 is held at the fully open position). .

When the bucket pin 6a has entered the front restraint area B1 (step S2), the left operating lever 1
If the arm 5 is moved to the rake side by operating 0 later (step S8), the bucket pin 6a is brought closer to the front restraint surface A1. In this state, the pilot pressure of the pilot valve 32a is reduced by the pressure control valve 42a shown in FIG. 3, and the scraping speed of the arm 5 (the second hydraulic cylinder 1
2 (the extension speed of the second hydraulic cylinder 12), the more the bucket pin 6a approaches the front restraint surface A1, the greater the speed at which the arm 5 is scraped (the extension speed of the second hydraulic cylinder 12). S11). Bucket pin 6a
Reaches the front restraint surface A1 (step S9), the pilot pressure of the pilot valve 32a is set to zero by the pressure control valve 42a shown in FIG. The second control valve 22 is operated to the neutral position, and the arm 5 (the second hydraulic cylinder 12) stops (step S10).

Conversely, when the left operation lever 10 is operated forward to operate the arm 5 to the earth discharging side (step S8), the bucket pin 6a is separated from the front restraint surface A1.
Even when the bucket pin 6a is located in the front restraint surface A1 and the front restraint area B1, the arm 5 is operated to the earth discharging side at a speed corresponding to the operation position of the front operation of the left operation lever 10 regardless of this. (Step S12) (The pressure control valve 42b of the pilot valve 32b of the left operating lever 10 shown in FIG. 3 is held at the fully open position).

When the bucket pin 6a has entered the front restraint area B1 (step S2), the operation pedal 39
When the second boom portion 4b is operated to the left swing side by operating the left side (step S13), the bucket pin 6a enters a state approaching the front restraint surface A1. In this state, the pilot pressure of the pilot valve 35a is reduced by the pressure control valve 43 shown in FIG. 3, and the left swing speed (the second swing speed) of the second boom portion 4b is independent of the operation position of the left pedal operation of the operation pedal 39. As the bucket pin 6a approaches the front restraint surface A1, the left swing speed of the second boom portion 4b (the extension speed of the fourth hydraulic cylinder 7) decreases. A large deceleration operation is performed (step S
16). When the bucket pin 6a reaches the front restraint surface A1 (step S14), the pilot pressure of the pilot valve 35a is set to zero by the pressure control valve 43 shown in FIG.
The fifth control valve 25 is operated to the neutral position regardless of the operation position of the left pedal operation of the operation pedal 39, and the second boom portion 4
b (the fourth hydraulic cylinder 7) stops (step S1)
5).

Conversely, when the operation pedal 39 is depressed to the right, the second
When the boom portion 4b is operated to the right swing side (step S1)
3) Since the bucket pin 6a is separated from the front restraint surface A1, even if the bucket pin 6a is located in the front restraint surface A1 and the front restraint area B1, the right depressing operation of the operation pedal 39 regardless of this. The second boom portion 4b is operated to the right swing side at a speed corresponding to the operation position (step S).
17) (As shown in FIG. 3, the pressure control valve 43 is provided in the pilot oil passage 55b of the pilot valve 35b of the operation pedal 39.
Is not provided).

(5) When an attempt is made to operate the bucket pin 6a to the operation unit 15 side beyond the lateral restraint surface A2, this operation is prevented from being restrained. Next, the restraint will be described. As described in the above item (4), in the control device 40, the angle of the first boom portion 4a and the second boom portion 4b based on the detection values of the angle sensors 36, 37, 38.
, The angle of the arm 5, and the lengths of the first boom portion 4a, the second boom portion 4b, and the arm 5, the position of the bucket pin 6a is always detected.

In a state where the bucket pin 6a has entered the lateral restraint area B2, when the operation pedal 39 is depressed to the left and the second boom portion 4b is operated to the left swing side, the bucket pin 6a moves to the lateral restraint surface A2. It is in a state of approaching. In this state, the pilot pressure of the pilot valve 35a is reduced by the pressure control valve 43 shown in FIG. 3, and the left swing speed of the second boom portion 4b (regardless of the operation position of the left pedal operation of the operation pedal 39). The deceleration operation of the fourth hydraulic cylinder 7) is performed. As the bucket pin 6a approaches the lateral restraint surface A2, the left swing speed of the second boom portion 4b (the extension speed of the fourth hydraulic cylinder 7). Is greatly decelerated. When the bucket pin 6a reaches the lateral restraint surface A2, the pilot valve 3 is activated by the pressure control valve 43 shown in FIG.
5a is set to zero and the operation pedal 39
The fifth control valve 25 is operated to the neutral position irrespective of the operation position of the left depressing operation, and the second boom portion 4b (the fourth hydraulic cylinder 7) stops.

Conversely, when the operation pedal 39 is depressed to the right, the second
When the boom portion 4b is operated to the right swing side, the bucket pin 6a is separated from the lateral restraint surface A2. Therefore, even if the bucket pin 6a is located in the lateral restraint surface A2 and the lateral restraint area B2, Irrespective of this, the second boom portion 4b is swung to the right at a speed corresponding to the operation position of the right stepping operation of the operation pedal 39 (as shown in FIG. 3, the second boom portion 4b is connected to the pilot oil passage 55b of the pilot valve 35b of the operation pedal 39). Is due to the fact that the pressure control valve 43 is not provided).

When the bucket pin 6a has entered the lateral restraint area B2, the first boom portion 4a can be moved up and down, or the arm 5 can be moved up and down. Since the bucket pin 6a does not enter the state of approaching the lateral restraint surface A2, the first boom portion 4 is not moved when the bucket pin 6a enters the lateral restraint area B2.
The operation on the ascending side and the descending side of a, and the operation on the scraping side and the earth discharging side of the arm 5 can be freely performed.

(6) Next, a state of straight excavation performed by moving the bucket pin 6a substantially linearly in the backhoe will be described with reference to FIG. In this straight excavation, the bucket pin 6a basically has the front and side restraint surfaces A
1, A2, at a position sufficiently distant from the front and lateral restraint areas B1, B2. As shown in FIG. 3, the positive operating position 46a for supplying the pilot pressure from the pilot valve 31b of the right operating lever 9 to the pressure control valve 41b, and the pilot pressure from the pilot valve 31a of the right operating lever 9 is applied to the pressure control valve 41b. A operable switching valve 46 is provided at a reverse operation position 46b which supplies the pilot oil to the pilot oil passage 51b. A pilot oil passage 47 branched from the pilot oil passage 51 a is connected to the switching valve 46.

With the above configuration, in a state where the straight excavation switch 44 shown in FIG. 3 is turned on (step S2).
1), as shown in FIG.
1st boom part 4a by right and left operation levers 9 and 10
Is operated on the descending side, and the arm 5 is operated on the earth discharging side to position the bucket pin 6a at a desired excavation start position E1 away from the swivel 2.

Next, the operator of the driving section 15 moves the right operating lever 9
Is operated later (step S22), and the left operating lever 1 is operated.
When 0 is operated later (step S23), the switching valve 46 is operated to the normal operation position 46a (steps S24, S2).
5) By the pilot pressure of the pilot valves 31a and 32a, the second control valve 22 of the arm 5 is operated to the squeezing side, and the arm 5 is operated to the squeezing side.
The first control valve 21a is operated upward and the first boom portion 4a is operated upward.

In this case, the angle sensors 36, 37, 38
8B, the position of the bucket pin 6a is always detected, and as shown in FIGS. 8A and 8B, the bucket pin 6a moves substantially along the straight path D1 starting from the desired excavation start position E1. The pressure control valves 41a, 41
2a is automatically operated and the first boom portion 4a
The control valve 21 and the second control valve 22 of the arm 5 are operated (Step S26). In the state shown in FIG. 8A, the straight line trajectory D1 is set to a horizontal state, but the angle setting dial 45 shown in FIG.
Can be arbitrarily set, for example, as a backward rising inclined angle or as a backward falling inclined angle.

After the arm 5 is operated to the scraping side from the desired excavation start position E1 and the first boom portion 4a is operated to the ascending side, as shown in FIG. When the angle sensors 36, 37, and 38 detect that the bucket pin 6a has reached the switching position E2 that is orthogonal to the switching position E2 (step S24), the switching valve 46 is operated to the reverse operation position 46b (step S27). The pilot pressure of the pilot valve 31a of the right operation lever 9 is supplied to the pressure control valve 41b via the pilot oil passages 51a and 47 and the switching valve 46.

Thus, while the right operating lever 9 is operated backward, the first control valve 21 of the first boom portion 4a is operated from the ascending side to the descending side so that the pilot valves 31a, 3
2a, the second control valve 22 of the arm 5
When the arm 5 is operated to the squeezing side by operating to the squeezing side, the first control valve 21 of the first boom portion 4a is operated to be lowered and the first boom portion 4a is operated to be lowered. You. In this case, the angle sensors 36, 37, 3
8, the position of the bucket pin 6a is always detected, and as shown in FIGS.
The pressure control valves 41b and 42a are automatically operated so that the bucket pin 6a moves substantially along the axis, and the first control valve 21 of the first boom portion 4a and the second control valve 22 of the arm 5 are moved. An operation is performed (step S28).

Next, the operator of the driving unit 15
If it is determined that “a” has reached the desired excavation end position E3 shown in FIG. 8 (c), the left operation lever 10 is operated forward (step S23) while the right operation lever 9 is operated backward (step S22). Thereby, the switching valve 46 is moved to the normal operation position 4.
6a (steps S29 and S32), the arm 5 is operated by the pilot pressure of the pilot valves 31a and 32b.
The second control valve 22 is operated to the earth discharging side, the arm 5 is operated to the earth discharging side, the first control valve 21 of the first boom portion 4a is operated to the ascending side, and the first boom portion 4a is moved to the ascending side. Is operated.

In this case, the angle sensors 36, 37, 38
8B, the position of the bucket pin 6a is always detected, and as shown in FIGS. 8 (c) and 8 (b), the bucket pin 6a moves substantially along a linear locus D1 starting from a desired excavation end position E3. The pressure control valves 41a, 41
2b is automatically operated, and the first control valve 21 of the first boom portion 4a and the second control valve 22 of the arm 5 are operated (Step S33).

After the arm 5 is operated to the earth discharging side from the desired excavation end position E3 and the first boom portion 4a is operated to the ascending side, the bucket pin is moved to the switching position E2 shown in FIG. 6a is reached, the angle sensor 36,
If detected by steps 37 and 38 (step S29),
The switching valve 46 is operated to the reverse operation position 46b (step S
30), the pilot pressure of the pilot valve 31a of the right operation lever 9 is supplied to the pressure control valve 41b via the pilot oil passages 51a and 47 and the switching valve 46.

Thus, while the right operating lever 9 is being operated backward, the first control valve 21 of the first boom portion 4a is operated from the ascending side to the descending side, and the pilot valves 31a, 3 are operated.
2b, the second control valve 22 of the arm 5
Is operated on the earth discharging side and the arm 5 is operated on the earth discharging side, the first control valve 21 of the first boom part 4a is operated on the descending side, and the first boom part 4a is operated on the descending side. You. In this case, the position of the bucket pin 6a is constantly detected based on the detection values of the angle sensors 36, 37, and 38, and the bucket pin 6a moves substantially along the linear locus D1 as shown in FIGS. The pressure control valves 41b and 42b are automatically operated so that the first control valve 21 of the first boom part 4a and the second control valve 22 of the arm 5 are operated.
Is operated (step S31).

Steps S26, S28, S31, S33
, The operator of the operating unit 15 needs to operate the right operating lever 9 afterward while the pressure control valves 41a, 41b, 42a, 42b are automatically operated. When the user operates the right operation lever 9 forward (step S22), the process proceeds to step S34 and the pressure control valve 4
1a, 41b, 42a, and 42b are held at the fully open position, and return to the normal excavation state.

As described above, the operator of the driving section 15 operates the right operating lever 9 rearward and then operates the left operating lever 10 backward and forward to reciprocate the bucket pin 6a substantially along the straight path D1. It can be moved (straight excavation by moving from the desired excavation start position E1 to the desired excavation end position E3, and linear straightening by moving from the desired excavation end position E3 to the desired excavation start position E1). In this case, while changing the desired excavation start position E1 as the starting point to a position slightly deeper than the previous operation, the above-described step S2 is performed.
By repeating the operations 2 to S33, the excavation depth by the bucket 6 can be gradually increased.

Between the desired excavation start position E1 and the switching position E2 shown in FIGS.
When the left operation lever 10 is operated backward and forward in the state where is operated backward, steps S22 to S26 and S29 to S31 are repeated, and the switching position E shown in FIGS.
When the left operating lever 10 is operated backward and forward while the right operating lever 9 is operated backward between the position 2 and the desired excavation end position E3, steps S22, S23, S27, S2 are performed.
8, S29, S32, and S33 are repeated.

[0057]

According to the first aspect of the present invention, in the backhoe, the operator of the turntable operates one and the other operation levers.
Only by operating the arm on the scraping side (discharge side) and the boom raising side, the
Alternatively, the operation position of the second control valve is automatically corrected, and the first control valve of the boom is automatically operated from the ascending side to the descending side, so that the tip (bucket) of the arm substantially follows a predetermined linear trajectory. It was possible to easily perform straight excavation and improve the workability of the backhoe. In this case, while the other operation lever is operated to the rising side of the boom, one of the operation levers is operated to the scraping side and the earth discharging side of the arm, so that the tip (bucket) of the arm follows a predetermined linear locus. Since the arm can be moved back and forth substantially, straight excavation by moving the arm to the scraping side and straightening of the arm by moving the arm to the earth discharging side can be easily and repeatedly performed. Workability was further improved.

According to the feature of the first aspect, the operator of the swivel table operates one of the operation levers to the side of scraping (the side of discharging earth),
In addition, based on the clear intention of the operator of the swivel base that the tip of the arm (bucket) is moved substantially along a predetermined linear trajectory, as in the case where the other operation lever is operated to the rising side of the boom. Then, the operation position of the first or second control valve with respect to one or the other operation lever is automatically corrected, the first control valve of the boom is operated from the ascending side to the descending side, and the tip (bucket) of the arm is moved. It moves substantially along a predetermined straight path. Accordingly, even if the first or second control valve is operated at the operation position slightly deviated from the operation position corresponding to the one or other operation lever, the first control valve of the boom is operated to the opposite descending side. However, the operator of the swivel base did not misunderstand that it was in an abnormal state, and it was possible to prevent the incorrect operation of the operator of the swivel base based on the misunderstanding.

According to the feature of the second aspect, the "effect of the invention" of the first aspect is provided similarly to the case of the first aspect. In addition to the "effect of the invention", the following "invention" is provided. Of the effect. According to the features of the second aspect, the configuration of the one and other operation levers, the pilot valve, the first and second control valves of the pilot operation type, and the pilot pressure can be added to these configurations without any particular change in the relationship between each part. It is only necessary to add the first, second, third, and fourth correction means for changing the operation of the backhoe, so that the structure can be relatively easily and easily adjusted without special modification to the existing pilot operation type backhoe. A backhoe that can perform straight excavation and leveling can be obtained.

[Brief description of the drawings]

FIG. 1 is an overall side view of a backhoe.

FIG. 2 is a hydraulic circuit diagram of a backhoe device.

FIG. 3 is a hydraulic circuit diagram showing right and left operation levers, operation pedals, pilot valves, pilot oil passages, and the like.

FIG. 4 is a side view showing a front restraint surface and a front restraint area.

FIG. 5 is a plan view showing front and side restraint surfaces and front and side restraint areas.

FIG. 6 is a diagram showing a first half of a control flow in a front restraint surface and a front restraint area.

FIG. 7 is a diagram showing the latter half of the control flow in the front restraint surface and the front restraint area.

FIG. 8 is a side view showing a state in which a bucket pin is moved substantially along a straight path.

FIG. 9 is a diagram showing a flow of control in a state where a bucket pin is moved substantially along a straight path.

[Explanation of symbols]

 2 swivel base 4 boom 5 arm 9,10 operating lever 11 first hydraulic cylinder 12 second hydraulic cylinder 21 first control valve 22 second control valve 31a, 31b, 32a, 32b pilot valve 36,38 angle sensor 41a, 42a, 46 first correction means 41b, 42a, 46 second correction means 41a, 42b, 46 third correction means 41b, 42b, 46 fourth correction means D1 predetermined linear trajectory E2 set position

Claims (2)

[Claims] 1. A first hydraulic cylinder for swinging a boom up and down, a first control valve for supplying and discharging hydraulic oil to and from the first hydraulic cylinder, and a second hydraulic cylinder for swinging an arm back and forth. A second control valve for supplying and discharging hydraulic oil to and from the second hydraulic cylinder;
And a pair of operating levers for operating a second control valve, an angle sensor for detecting an angle of the boom with respect to a swivel, and an angle sensor for detecting an angle of the arm with respect to the boom, When the other operation lever is operated on the rising side of the boom while the operation lever is operated on the scraping side of the arm, the tip of the arm moves substantially along a predetermined linear locus. A first operation of correcting an operation position of the first or second control valve with respect to the one or other operation lever on a rising side of the boom or a squeezing side of the arm based on a detection value of the angle sensor;
When the tip of the arm reaches the set position of the predetermined linear trajectory by the first correction means, the first control valve is actuated with respect to the other operation lever operated on the rising side of the boom. Operate on the lower side of the boom, and move the tip of the arm substantially along the predetermined linear trajectory,
A second correction unit configured to correct an operation position of the first or second control valve with respect to the one or other operation lever on a descending side of the boom or a squeezing side of the arm based on a detection value of the angle sensor. When the other operation lever is operated to the rising side of the boom in a state where the one operation lever is operated to the earth discharging side of the arm, the tip of the arm substantially follows a predetermined linear locus. So that the operating position of the first or second control valve with respect to the one or other operating lever is set on the rising side of the boom or on the earth discharging side of the arm based on the detection value of the angle sensor. A third correcting means for correcting, and when the tip of the arm reaches the set position of the predetermined linear trajectory by the third correcting means, the other operation level operated on the rising side of the boom Said first control valve to operate the descending side of the boom relative to chromatography, and, as the tip of the arm is moved substantially along the predetermined line trajectory,
A fourth correction unit configured to correct an operation position of the first or second control valve with respect to the one or other operation lever on a lowering side of the boom or a discharging side of the arm based on a detection value of the angle sensor. A backhoe equipped with 2. A first hydraulic cylinder for swinging the boom up and down, a first pilot-operated control valve for supplying and discharging hydraulic oil to and from the first hydraulic cylinder, and an arm for swinging the arm back and forth. A second hydraulic cylinder, a pilot-operated second control valve for supplying and discharging hydraulic oil to and from the second hydraulic cylinder, and a pair of artificially operated first and second control valves for operating the first and second control valves. An angle sensor, comprising: an operation lever; a pilot valve that generates a pilot pressure for operating the first and second control valves in accordance with the operation positions of the pair of operation levers; And an angle sensor for detecting an angle of the arm with respect to the boom. In a state where the one operation lever is operated to the rake side of the arm, the other operation lever is connected to the boom. A pilot that operates the first or second control valve based on the detection value of the angle sensor so that the tip of the arm moves substantially along a predetermined linear trajectory when the arm is operated on the ascending side of the arm. A first correcting means for changing a pressure to change an operation position of the first or second control valve with respect to the one or other operation lever on a rising side of the boom or a squeezing side of the arm; When the tip of the arm reaches the set position of the predetermined linear trajectory by the first correction means, the first control valve is moved to the lower side of the boom with respect to the other operation lever operated to the upper side of the boom. And so that the tip of the arm moves substantially along the predetermined linear trajectory,
Based on the detected value of the angle sensor, by changing the pilot pressure for operating the first or second control valve, the operation position of the first or second control valve with respect to the one or the other operation lever, Second correcting means for correcting the lowering side of the boom or the scraping side of the arm; and a state in which the one operating lever is operated on the discharging side of the arm and the other operating lever raises the boom. When operated to the side, the pilot pressure for operating the first or second control valve is changed based on the detection value of the angle sensor so that the tip of the arm moves substantially along a predetermined linear trajectory. Operating the first or second control valve with respect to the one or other operation lever to correct the operation position on the rising side of the boom or on the earth discharging side of the arm; When the tip of the arm reaches the set position of the predetermined linear trajectory by the correction means, the first control valve is operated to the lower side of the boom with respect to the other operation lever operated to the upper side of the boom. And, so that the tip of the arm moves substantially along the predetermined linear trajectory,
Based on the detected value of the angle sensor, by changing the pilot pressure for operating the first or second control valve, the operation position of the first or second control valve with respect to the one or the other operation lever, A backhoe comprising: a fourth correction unit configured to perform correction on a lowering side of the boom or a discharging side of the arm.