JP2000328596A - Back hoe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce load on a calculation device when a back hoe is formed so that a bucket is avoided from being in contact with an operating part. SOLUTION: A back hoe comprises a boom vertical angle sensor 36 detecting a vertical angle a1 of a boom 4 relative to a swing table 2 and an arm longitudinal angle sensor 38 detecting a longitudinal angle a3 of an arm 5 relative to the boom 4. When a detection value of the arm longitudinal angle sensor 38 relative to a detection angle of a boom vertical angle sensor 36 reaches a set value, the bucket 6 is judged to reach a position apart by a specified distance from an operating part 15 and the operation of the arm 5 to the scraping-in side is suppressed. When the detection value of the boom vertical angle sensor 36 changes to the rise side and the detection value of the boom longitudinal angle sensor 38 changes to the scraping-in side, the arm 5 is operated to the soil exhausting side automatically.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing a contact between an operating unit and a bucket of a backhoe apparatus in a backhoe.

[0002]

2. Description of the Related Art In a backhoe, an operation section is covered with a canopy or a cabin, and an example of a structure for avoiding contact between an operation section (a canopy or a cabin) and a bucket is disclosed in Japanese Patent Laid-Open No. 6-17452. I have. In this structure, the driving unit (16, 17 in FIGS. 3 and 4 of the above publication)
Then, a check surface (A1, A2 in FIGS. 3 and 4 of the above-mentioned publication) separated by a predetermined distance is set as a space, and the position of the bucket (6a in FIGS. 3 and 4 of the above-mentioned publication) is detected. A position sensor and a check means for stopping the hydraulic cylinder of the backhoe device when the bucket attempts to enter the operation unit side beyond the check surface based on the detection of the position sensor.

In this case, the check surface is set in a three-dimensional space based on the driving unit (turntable) by XYZ coordinates. On the other hand, the position of the bucket is determined by a boom vertical angle sensor (36 in FIG. 6 in the above publication) for detecting the vertical angle of the boom with respect to the swivel table, and an arm front / back angle sensor (36 in FIG. FIG.
38), which is calculated based on the lengths of the boom and the arm determined in advance, and the detection values of the boom vertical angle sensor and the arm longitudinal angle sensor. It is represented by XYZ coordinates in a dimensional space. In this way, the check surface is set by XYZ coordinates,
By expressing the position of the bucket in XYZ coordinates, the positional relationship between the check surface and the bucket is recognized in XYZ coordinates. With the above configuration, when the operator of the driving unit is operating the backhoe device, even if an operation is performed such that the bucket is accidentally brought close to the driving unit side and brought into contact with the driving unit,
When the bucket reaches the check surface, the backhoe device automatically stops, and contact of the bucket with the operating unit is avoided.

[0004]

As described above, when the position of the bucket is represented by XYZ coordinates, the detection value of the boom vertical angle sensor (boom vertical angle with respect to the swivel table), the boom length, and the arm longitudinal angle sensor Since the XYZ coordinates of the position of the bucket are calculated using a trigonometric function based on the detected value (the front-rear angle of the arm with respect to the boom) and the length of the arm, the calculation processing is complicated. As a result, the load on the arithmetic unit that performs the arithmetic processing becomes large, and there is room for improvement in reducing the load on the arithmetic unit. An object of the present invention is to reduce the load on the arithmetic unit when the backhoe is configured to avoid contact of the bucket with the driving unit.

[0005]

Means for Solving the Problems [I] In the backhoe, a boom is swingably supported on a swivel table, and an arm is swingably supported on a tip of the boom, and a bucket is provided on a tip of the arm. Supported. Thus, according to the feature of the first aspect, if the vertical angle of the boom with respect to the swivel base and the front-rear angle of the arm with respect to the boom are determined with the length of the boom and the arm being determined, the bucket supported at the tip of the arm is The position is uniquely determined. Therefore, according to the features of claim 1, even if the XYZ coordinates of the position of the bucket are not calculated using the trigonometric function, the detected value of the boom vertical angle sensor and the detected value of the arm front-rear angle sensor are used as the bucket position. The value can be used as a parameter indicating the position of the bucket.

According to the first aspect of the present invention, when a detection value of the boom vertical angle sensor reaches a set value when the arm is operated to the scraping side and the arm front-rear angle sensor reaches a set value, the bucket is moved from the driving unit. When it is determined that the arm has reached the position separated by a predetermined distance, the operation of the arm on the scraping side is prevented from being restrained, whereby the contact of the bucket with the driving unit is avoided. In this case, if the detection value of the boom vertical angle sensor changes, the set value (the detection value of the arm front-rear angle sensor) when the bucket reaches a position separated by a predetermined distance from the driving unit also changes accordingly.

[II] In the backhoe, when excavating the ground, the soil on the ground is scraped off by a bucket, and then the operation of raising the boom and the operation of scraping the arm are simultaneously performed to obtain the bucket. Is often moved above the swivel table. Thus, for example, if the operation of raising the boom and the operation of moving the arm are performed simultaneously with the bucket positioned slightly forward from the operating unit, the bucket quickly approaches the operating unit. This is because if the boom is operated upward, the horizontal component of the boom's arc movement causes the boom tip (arm) to move to the operation unit side. In addition to the movement, the arm is operated to the rake side, so that the bucket quickly approaches the operating unit.

According to the first aspect of the present invention, the operation of raising the boom and the operation of squeezing the arm are simultaneously performed, and the detection value of the boom vertical angle sensor changes to the rising side, and the arm longitudinal angle is changed. When the detection value of the sensor changes to the scraping side, the arm is automatically moved to the earth discharging side (or the operation of the arm to the scraping side is automatically prevented from being restrained).
(Or, the operation of the arm to the squeezing side is automatically decelerated), so that the bucket is prevented from rapidly approaching the driving unit.

[III] According to the feature of the second aspect, similar to the first aspect, the "action" described in the above [I] and [II] is provided, and in addition, the following "action" is provided. "
It has. In the backhoe, generally, when the boom is operated on the ascending side, the arm (bucket) at the tip of the boom comes closer to the operating unit due to the horizontal component of the circular operation toward the ascending side of the boom.

Thus, as described in the preceding section [I],
According to the feature of claim 2, in a state where the position of the bucket supported on the tip of the arm is uniquely determined by the vertical angle of the boom with respect to the swivel table and the longitudinal angle of the arm with respect to the boom, At a certain detection value, when the boom is operated to the rising side and the detection value of the boom vertical angle sensor reaches a set value, it is determined that the bucket has reached a position at a predetermined distance from the driving unit, and the boom is moved to the rising side. The operation of the bucket is prevented, so that the bucket does not contact the driving unit. In this case, if the detection value of the arm front-rear angle sensor changes,
The set value (detected value of the boom vertical angle sensor) when the bucket reaches a position separated by a predetermined distance from the driving unit also changes accordingly.

As described above, when the detection value of the boom vertical angle sensor reaches the set value with respect to the detection value of the arm front-rear angle sensor, the operation of raising the boom is prevented from being restrained. In this case, when the operation of raising the boom and the operation of squeezing the arm are performed simultaneously as described in [II] above, detection of the boom vertical angle sensor with respect to the detection value of the arm longitudinal angle sensor is performed. When the value reaches the set value, the operation of raising the boom is stopped,
It is conceivable that the operation on the rising side of the boom cannot be performed.

In this case, according to the feature of claim 2, when the operation of raising the boom and the operation of moving the arm to the scraping side are performed simultaneously, the arm is automatically operated to the earth discharging side. (Or because the operation of the arm on the squeezing side is automatically inhibited), (or because the operation of the arm on the squeezing side is automatically decelerated), the bucket quickly approaches the driving unit. When the state is avoided and the operation of the boom raising side and the operation of the arm scraping side are performed at the same time, the detection value of the boom vertical angle sensor becomes the set value with respect to the detection value of the arm front and rear angle sensor. Is reached, and a situation in which the operation of the boom on the ascending side cannot be performed can be avoided.

[IV] According to the feature of the third aspect, similar to the case of the first or second aspect, the "action" described in the above-mentioned [I] to [III] is provided. It has various “actions”. According to the feature of claim 3, when the operation of raising the boom and the operation of moving the arm to the scraping side are performed simultaneously, the arm is immediately operated to the earth discharging side (immediately when the arm is moved to the scraping side). If the operation is prevented from being restrained (the operation of the arm on the squeezing side is immediately decelerated) and the situation where the bucket rapidly approaches the driving unit is avoided, the operator of the driving unit may feel uncomfortable. is there. This is because the operator of the driving unit attempts to move the bucket closer to the driving unit, and simultaneously performs the operation of moving the boom upward and the operation of moving the arm to the scraping side, but the bucket does not approach the driving unit very much. This is because such a state occurs.

According to the third feature, when the operation of raising the boom and the operation of sweeping the arm are performed simultaneously, the arm is operated to the earth discharging side after a lapse of a set time. Since the operation of the arm on the rake side is inhibited after the set time has elapsed (because the operation of the arm on the rake side is decelerated after the lapse of the set time), the operation of the boom up side and When the operation of the arm on the scraping side is performed simultaneously, the arm is automatically moved to the earth discharging side after the bucket has approached the driving unit to some extent (the arm is automatically scraped). The operation to the squeeze side is inhibited (the operation to the squeeze side of the arm is automatically decelerated), and the bucket rises near the front of the driving unit. You can get something like that.

[V] According to the features of claim 4, claim 1
As in any one of [3] to [3],
It has the “action” described in [IV], and additionally has the following “action”. According to the feature of claim 4, the operation of raising the boom and the operation of scraping the arm are performed simultaneously, and the arm is automatically moved to the earth discharging side (or the arm is automatically moved). When the operation on the squeezing side is prevented from being restrained (or when the operation on the squeezing side of the arm is automatically decelerated), the operation on the ascending side of the boom is decelerated. Thus, according to the fourth aspect of the present invention, when the boom is operated on the ascending side, the horizontal component of the arc operation of the boom causes the state in which the tip (arm) of the boom moves toward the operation unit side. Operation is suppressed by the deceleration operation,
When the operation of raising the boom and the operation of moving the arm to the rake side are simultaneously performed, the state in which the bucket rapidly approaches the driving unit is further suppressed.

[VI] According to the feature of claim 5, as in the case of claim 4, the "action" described in the above items [I] to [V].
And the following “action” in addition to this. When the boom is operated upward, the vertical angle of the boom approaches the angle at which the boom stands upright on the swivel,
The horizontal component of the boom arc actuation is greater. According to the fifth aspect of the present invention, when the operation of the boom to the rising side and the operation of the arm to the scraping side are performed simultaneously, and the arm is automatically operated to the earth discharging side (or automatically). If the operation of the arm on the rake side is prevented from being restrained)
(Or, if the operation of the arm on the scraping side is automatically decelerated, the operation of the boom on the ascending side is greatly reduced as the vertical angle of the boom approaches the angle at which the boom stands upright on the swivel. Therefore, the state in which the bucket rapidly approaches the driving unit is further suppressed.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [1] FIG. 1 shows the entire side surface of a backhoe. A swivel 2 is supported on a traveling device 1 of a rubber crawler type, and a backhoe 3 is provided in front of the swivel 2. ing. The backhoe device 3 includes the hydraulic cylinder 1
1 is provided with a boom 4 oscillating vertically, an arm 5 oscillating back and forth by a hydraulic cylinder 12, and a bucket 6 oscillating by a hydraulic cylinder 13.

The boom 4 of the backhoe device 3 includes a first boom 4a which is vertically swung, a second boom 4b which is swingably connected around an axis P1 at the front end of the first boom 4a,
The second boom 4b is constituted by a support bracket 4c that is swingably connected around the axis P2 at the front end of the second boom 4b, and the arm 5 is connected to the support bracket 4c. First boom 4
and a support bracket 4c, a link 4 is erected to form a parallel quadruple link, and the hydraulic cylinder 7 swings the second boom 4b with respect to the first boom 4a, so that the arm 5 and the bucket 6 are moved left and right.

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

[2] Next, the 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 control valve 21 of the hydraulic cylinder 11 of the first boom 4a (boom 4), the control valve 22 of the hydraulic cylinder 12 of the arm 5, and the control valve 2 of the hydraulic cylinder 13 of the bucket 6
3, the control valve 24 of the turning motor 18 of the turning table 2, the control valve 25 of the hydraulic cylinder 7 of the second boom 4b, the right traveling device 1
, A control valve 27 of the left traveling device 1, a control valve 28 of a service port (not shown), and a control valve 29 of a hydraulic cylinder 51 for raising and lowering the dozer 19 shown in FIG.
Is provided, and hydraulic oil from the pump 20 is supplied to the control valve 2.
1 to 29.

The control valve 21 of the first boom 4a, the control valve 22 of the arm 5, the control valve 23 of the bucket 6, the control valve 24 of the swivel 2 and the control valve 25 of the second boom 4b are operated by a pilot operation system using a pilot pressure. It is configured as a neutral return type. The control valves 26 and 27 of the right and left traveling devices 1, the control valve 28 of the service port, and the control valve 29 of the dozer 19 are configured as a mechanically operated neutral return type operated by an operation lever (not shown). ing.

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 operation 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 operation lever 10, and the pilot pressure is generated by the front operation of the left operation 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 FIG. 3 and FIG. 5, an operation pedal 39 which can be operated to be depressed right and left is provided.
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, 31b of the right operating lever 9 and the control valve 21 of the first boom 4a, and the pilot valves 33a, 33a,
The control valve 33b and the control valve 23 of the bucket 6 are connected via a pilot oil passage, and the pilot valves 32a and 32b of the left operation lever 10 and the control valve 22 of the arm 5, and the pilot valves 34a and 34a of the left operation lever 10, 34b and swivel 2
Is connected through a pilot oil passage. The pilot valves 35a and 35b of the operation pedal 39 and the control valve 25 of the second boom portion 4b are connected via a pilot oil passage.

When the right operation lever 9 is operated backward by the above structure, the pilot pressure from the pilot valve 31a causes
When the control valve 21 of the first boom 4a is raised (the hydraulic cylinder 1
When the right operating lever 9 is operated forward, the pilot pressure from the pilot valve 31b causes the first operation lever 9 to operate.
The control valve 21 of the boom 4a is operated on the descending side (the contraction side of the hydraulic cylinder 11). When the right operation lever 9 is operated to the right, the control valve 23 of the bucket 6 is operated to the discharging side (the contraction side of the hydraulic cylinder 13) by the pilot pressure from the pilot valve 33a, and when the right operation lever 9 is operated to the left, the pilot valve 33b is operated. The control valve 23 of the bucket 6 on the squeezing side (extension side of the hydraulic cylinder 13)
Is operated.

When the left operating lever 10 is operated backward, the control valve 22 of the arm 5 is operated to the squeezing side (extension side of the hydraulic cylinder 12) by the pilot pressure from the pilot valve 32a, and when the left operating lever 10 is operated forward. The control valve 2 of the arm 5 is controlled by the pilot pressure from the pilot valve 32b.
2 is operated to the earth discharging side (the contracting side of the hydraulic cylinder 12). When the left operating lever 10 is operated to the right, the pilot valve 34
When the control valve 24 of the swivel 2 is operated to the right turning side by the pilot pressure from a, and when the left operating lever 10 is operated to the left, the control valve 24 of the swivel 2 is turned left by the pilot pressure from the pilot valve 34b. Operated to the side.

When the operation pedal 39 is depressed to the left, the second boom 4 is actuated by the pilot pressure from the pilot valve 35a.
b control valve 25 is on the left swing side (extension side of hydraulic cylinder 7)
When the operation pedal 39 is depressed to the right, the second boom 4 is actuated by the pilot pressure from the pilot valve 35b.
b control valve 25 is on the right swing side (contracting side of hydraulic cylinder 7)
Is operated.

As the right and left operating levers 9 and 10 and the operating 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 corresponding to the operation positions of the right and left operation levers 9, 10 and the operation pedal 39, and the control valves 21 to 25 The right and left operation levers 9 and 10 and the operation pedal 3 are operated to the large side.
The larger the number 9 is operated, the more hydraulic cylinders 7, 11, 12,
13 and the turning motor 18 operate at high speed.

[3] As shown in FIGS. 4 and 5, a boom vertical angle sensor 36 for detecting the vertical angle a1 of the first boom 4a with respect to the swivel 2 is provided at the connection between the swivel 2 and the first boom 4a. Provided, the first and second booms 4a, 4
b, the second boom 4b with respect to the first boom 4a
Boom left / right angle sensor 37 for detecting the left / right angle a2 of the boom
(A left-right angle a2 with respect to a position (see a two-dot chain line in FIG. 5) at which the second boom 4b is swung to the limit on the left swing side). The front-rear angle a3 of the arm 5 with respect to the second boom 4b is provided at the connection between the support bracket 4c and the arm 5.
The detection values of the boom vertical angle sensor 36, the boom left / right angle sensor 37, and the arm front / rear angle sensor 38 are input to the control device 40 as shown in FIG.

As shown in FIG. 3, a pilot oil passage connecting the pilot valve 31a of the right operating lever 9 and the control valve 21 of the first boom 4a (the pilot oil passage for operating the control valve 21 of the first boom 4a upward). Oil passage), a pilot oil passage connecting the pilot valve 32a of the left operating lever 10 and the control valve 22 of the arm 5 (a pilot oil passage for operating the control valve 22 of the arm 5 to the scraping side), and A pilot oil passage connecting the pilot valve 35a and the control valve 25 of the second boom 4b (the control valve 25 of the second boom 4b)
) Are provided with electromagnetically operated pressure control valves 41, 42, and 43, respectively.

Therefore, the pilot pressure is reduced by the pressure control valves 41, 42, 43 (the maximum pressure is the value set by the right and left operating levers 9, 10 and the operating pedal 39), and the right and left operating levers are controlled. 9, 10, regardless of the operation position of the operation pedal 39, the opening of the control valve 21 of the first boom 4a on the rising side, the opening of the control valve 22 of the arm 5 on the scraping side, and the control valve of the second boom 4b. 25 can be arbitrarily changed on the left swing side. By setting the pilot pressure to zero by the pressure control valves 41, 42, and 43, the hydraulic cylinder 11 of the first boom 4a and the arm 5 of the arm 5 are independent of the operation positions of the right and left operation levers 9, 10 and the operation pedal 39. The hydraulic cylinder 12 and the hydraulic cylinder 7 of the second boom 4b can be stopped.

[4] Next, control in the case where the first boom 4a is moved upward and downward will be described with reference to FIG. The detected value of the boom vertical angle sensor 36 (first
Boom 4a vertical angle a1), boom left / right angle sensor 37 (left / right angle a2 of second boom 4b), and arm front / rear angle sensor 38 detection values (front / rear angle a of arm 5)
3) is always input to the control device 40 (step S1).

After the right operating lever 9 is operated backward, the first boom 4
When a is operated on the ascending side, the bucket 6 comes into a state of approaching the driving unit 15. Thereby, when the right operating lever 9 is operated backward and the vertical angle a1 of the first boom 4a changes to the rising side (when the vertical angle a1 of the first boom 4a increases) (step S2), Second boom 4b
The first set angle BO1 and the second set angle BO2 are calculated by the relational expressions fb1 and fb2 based on the left / right angle a2 and the front / rear angle a3 of the arm 5 (step S3).

In this case, the vertical angle a1 of the first boom 4a
Does not reach the first set angle BO1 (step S
6, S7), it is determined that the bucket 6 is still at a position sufficiently far from the driving unit 15, and a pilot pressure corresponding to the operating position of the right operating lever 9 is generated, and the bucket 6 is corresponding to the operating position of the right operating lever 9. The first boom 4a is moved upward at the speed (step S8).

Next, the vertical angle a1 of the first boom 4a is equal to the first angle.
When the angle exceeds the set angle BO1 (steps S7 and S9), it is determined that the bucket 6 has approached the operation unit 15 beyond the position separated by the first predetermined distance from the operation unit 15, and the vertical angle a1 of the first boom 4a is determined. Δa between the angle and the first set angle BO1
1 is calculated (step S10). This gives the difference Δ
3, the pilot pressure of the pilot valve 31a is reduced by the pressure control valve 41 shown in FIG.
The operation of increasing the pressure a (decompression speed of the hydraulic cylinder 11) is decelerated, and as the difference Δa1 increases (the closer the bucket 6 approaches the operating unit 15), the first boom 4a
(The extension speed of the hydraulic cylinder 11) is greatly reduced (step S11).

Next, the vertical angle a1 of the first boom 4a is
When the set angle BO2 is reached (step S9), it is determined that the bucket 6 has reached a position separated by a second predetermined distance from the operating unit 15, and the pilot pressure of the pilot valve 31a is increased by the pressure control valve 41 shown in FIG. After the unloading, the operation of raising the first boom 4a (extending operation of the hydraulic cylinder 11) is inhibited regardless of the operation position of the rear operation of the right operation lever 9 (step S12).

Conversely, when the right operating lever 9 is operated forward, the first
When the vertical angle a1 of the boom 4a changes to the descending side (when the vertical angle a1 of the first boom 4a decreases) (step S2), the bucket 6 is separated from the operating unit 15, so that the right operating lever 9 A pilot pressure corresponding to the operation position of the previous operation is generated, and the first boom 4a is operated to descend at a speed corresponding to the operation position of the front operation of the right operation lever 9 (step S13) (see FIG. 3). As described above, the pressure control valve 41 is not provided in the pilot oil passage of the pilot valve 31b of the right operation lever 9).

[5] As described in the preceding section [4], the first and second set angles BO1 and BO2 calculated by the relational expressions fb1 and fb2 in step S3 are equal to the left-right angle a2 of the second boom 4b and the arm When the front-rear angle a3 of the arm 5 changes, the front-rear angle a3 of the arm 5 decreases as the left-right angle a2 of the second boom 4b decreases.
Becomes smaller, the first and second set angles BO1, BO2
Becomes smaller.

Thus, the right and left angle a of the second boom 4b
2 and the bucket pin 6a when the vertical angle a1 of the first boom 4a reaches the first set angle BO1 (corresponding to the front-rear angle a3 of the arm 5). Fig. 4
As shown in FIG. 5, a planar trajectory B <b> 1 that is away from the driving unit 15 (the vertical and upper partition plates 16 and 17) by a first predetermined distance is provided. By connecting the position of the bucket pin 6a when the vertical angle a1 of the first boom 4a reaches the second set angle BO2, corresponding to the left-right angle a2 of the second boom 4b and the front-back angle a3 of the arm 5, The trajectory A1 is a planar trajectory A1 that is separated by a second predetermined distance from the driving unit 15 (the vertical and upper partition plates 16, 17).

In this case, the vertical angle a1 of the first boom 4a
Has reached the second set angle BO2 (the bucket pin 6a).
Is located on the locus A1), the bucket 6 is separated from the front edge of the vertical partition plate 16 and the front edge of the upper partition plate 17 by a predetermined distance even if the bucket 6 is swung so as to be closest to the driving unit 15. The second set angle BO2 (trajectory A1) is set so that the tip of the bucket 6 is located on the locus C1.

As shown in FIG. 5, the left-right angle a2 of the second boom 4b is equal to a predetermined angle (the first and second angles in the configuration shown in FIG. 5).
When the booms 4a and 4b exceed a state where the second boom 4b is located on the right swing side from a state in which the booms 4a and 4b are linearly moved), the bucket 6 moves away from the driving unit 15 to the right side. The bucket 6 does not come into contact with the driving unit 15 (the vertical and upper partition plates 16 and 17) even if the 4a is operated on the ascending side and the descending side. Thus, when the left-right angle a2 of the second boom 4b becomes larger than the above-mentioned predetermined angle, the first and second set angles BO1, BO2 calculated by the relational expressions fb1, fb2 in step S3 become sufficiently large values ( (A large value exceeding the rising limit of the first boom 4a), so that the first boom 4a can be operated up to the rising limit.

When the first boom 4a is about to be operated to the upper limit, if the vertical angle a1 of the first boom 4a reaches the third set angle BO3 slightly before the upper limit (step S4), it is shown in FIG. The pilot pressure of the pilot valve 31a is reduced by the pressure control valve 41, so that the operation of raising the first boom 4a to the rising side (the extension speed of the hydraulic cylinder 11) is performed irrespective of the operation position of the rear operation of the right operation lever 9. The deceleration operation is performed (step S5), and the first boom 4a is operated.
When the pressure reaches the rising limit, the relief valve 45 shown in FIG. 2 is opened, and the first boom 4a (the hydraulic cylinder 11) stops.

When the left and right angle a2 of the second boom 4b has reached the above-mentioned predetermined angle and the first boom 4a is operated upward and downward, the positions of the bucket pins 6a are connected. As shown in FIG. 5, the trajectory A <b> 2 is a planar trajectory A <b> 2 that is separated from the driving unit 15 (the vertical and upper partition plates 16 and 17) by a first predetermined distance to the right and left. In this case, in the state where the left-right angle a2 of the second boom 4b has reached the above-mentioned predetermined angle (the state where the bucket pin 6a is located on the trajectory A2), the bucket 6 The predetermined angle (trajectory A) is set so that the left lateral side is positioned.
2) is set.

[6] Next, control when the arm 5 is operated to the scraping side while the first boom 4a is operated to the upward side will be described with reference to FIG. When the left operating lever 10 is operated backward by operating the left operating lever 10 to move the arm 5 to the scraping side while the right operating lever 9 is operated to operate the first boom 4a to the ascending side, the bucket 6 quickly moves to the driving unit 15. It is in a state of approaching. As shown in FIG. 3, pressure control for connecting a pilot oil passage 45 for branching the pilot pressure from the pilot pump 30 to a pilot oil passage connecting the pilot valve 32b of the left operation lever 10 and the control valve 22 of the arm 5 A valve 44 is provided, and normally the pressure control valve 44 is held in a closed position.

When the right operating lever 9 is operated backward to change the vertical angle a1 of the first boom 4a to the rising side (when the vertical angle a1 of the first boom 4a increases) (step S)
2) Based on the vertical angle a1 of the first boom 4a and the horizontal angle a2 of the second boom 4b at this time, step S3
The third set angle AR3 is calculated by the relational expression fa3 (step S3).

In a state where the right operating lever 9 is operated backward and the vertical angle a1 of the first boom 4a changes to the rising side (step S2), the left operating lever 10 is operated backward and the arm 5 is operated to the scraping side. If it is determined (step S6) that the front-rear angle a3 of the arm 5 has not reached the third set angle AR3, it is determined that the bucket 6 is still far enough from the operation unit 15 and the right and left operation levers are determined. A pilot pressure corresponding to the operating positions of the operating levers 9 and 10 is generated, the first boom 4a is operated to the ascending side at the speed corresponding to the operating positions of the right and left operating levers 9 and 10, and the arm 5 is operated to the scraping side. Is done.

Next, when the front-rear angle a3 of the arm 5 exceeds the third set angle AR3 (step S14), the bucket 6 is moved from the operation unit 15 by a third predetermined distance (the first item described in the above item [4]).
It is determined that the vehicle has approached the operation unit 15 beyond a position distant from the operation unit 15 (a position farther than the set distance), and the pilot pressure of the pilot valve 32a is unloaded by the pressure control valve 42 shown in FIG. At the same time that the pilot pressure is supplied to the control valve 22 (discharge side) of the arm 5 by the control valve 44 and the first boom 4a is operated to the rising side,
Regardless of the operation position of the rear operation of the left operation lever 10, the arm 5 is operated at a low speed toward the earth discharging side (the contraction operation of the hydraulic cylinder 12) (step S15).

As described above, at the same time when the first boom 4a is operated to the raising side and the arm 5 is operated to the discharging side at a low speed regardless of the operation position of the rear operation of the left operation lever 10, Regardless of the operation position of the right operation lever 9 after the operation, the pilot pressure of the pilot valve 31a is reduced by the pressure control valve 41 shown in FIG. 3, and the operation of the first boom 4a to the rising side is decelerated. (Step S16).

When the first boom 4a is operated upward, the smaller the vertical angle a1 of the first boom 4a (the more the first boom 4a lies in parallel with the swivel 2), the more the first boom 4a is placed.
When the boom 4a is moved upward, the first boom 4a
The horizontal component of the movement of the tip (the arm 5 and the bucket 6) of the first boom to the driving unit 15 is small, so that
When the vertical angle a1 of the first boom 4a is small, the operation of raising the first boom 4a to the ascending side is not so much performed in step S16.

Conversely, the greater the vertical angle a1 of the first boom 4a (the more the first boom 4a stands upright with respect to the swivel base 2), the more the first boom 4a moves upward. Tip of the first boom 4a (arm 5 and bucket 6)
Since the horizontal component of the movement of the first boom 4a to the driving unit 15 is large, when the vertical angle a1 of the first boom 4a is large,
In step S16, the operation of moving the first boom 4a upward is greatly decelerated.

As described above, the right and left operation levers 9, 10
When the arm 5 is operated to the scraping side while the first boom 4a is operated to the ascending side by operating the first boom 4a
The operation on the ascending side of the vehicle is being decelerated (first boom 4
The operation of the first boom 4a on the ascending side is greatly decelerated as the up-down angle a1 of the arm a increases, and the arm 5 is operated at a low speed toward the earth discharging side.
As shown in step S12, the operation of the first boom 4a on the ascending side is not prevented from being restrained, and the first boom 4a is operated on the ascending side, so that the bucket 6 moves upward on the front side of the driving unit 15 and Go.

[7] Next, control when the arm 5 is operated to the scraping side and the earth discharging side will be described with reference to FIG. As described in the preceding section [4], the detection value of the boom vertical angle sensor 36 (the vertical angle a of the first boom 4a)
1) The values detected by the boom left / right angle sensor 37 (the left / right angle a2 of the second boom 4b) and the arm front / rear angle sensor 38 (the front / rear angle a3 of the arm 5) are constantly input to the control device 40 (step S1). ).

When the left operation lever 10 is operated later to operate the arm 5 to the scraping side, the bucket 6 comes into a state of approaching the operation unit 15. Thereby, when the left operating lever 10 is operated backward, and the front-rear angle a3 of the arm 5 changes to the scraping side (when the front-rear angle a3 of the arm 5 decreases).
(Step S17) Based on the vertical angle a1 of the first boom 4a and the horizontal angle a2 of the second boom 4b at this time, the first set angle AR1 and the second set angle AR2 are calculated by the relational expressions fa1 and fa2. (Step S1
8).

In this case, the front-rear angle a3 of the arm 5 is equal to the first angle.
If the set angle AR1 has not been reached (step S2
1), it is determined that the bucket 6 is still at a position sufficiently far from the driving unit 15, and a pilot pressure corresponding to the operation position of the left operation lever 10 is generated, and the bucket 6 is driven at a speed corresponding to the operation position of the left operation lever 10. The arm 5 is operated to the scraping side (step S22).

Next, when the front-rear angle a3 of the arm 5 exceeds the first set angle AR1 (steps S21 and S23), the bucket 6 approaches the driving unit 15 beyond the position separated from the driving unit 15 by the first predetermined distance. Then, the difference Δa3 between the front-rear angle a3 of the arm 5 and the first set angle AR1 is calculated (step S24). Thereby, the pilot valve 3 is controlled by the pressure control valve 42 shown in FIG.
2a is operated to reduce the pilot pressure, and the left operating lever 1 is operated.
0, irrespective of the operation position of the post-operation, the operation of the arm 5 toward the scraping side (the extension speed of the hydraulic cylinder 12) is decelerated, and as the difference Δa3 increases (the bucket 6
The operation of the arm 5 toward the squeezing side (extension speed of the hydraulic cylinder 12) is greatly reduced (step S25).

Next, when the front-rear angle a3 of the arm 5 reaches the second set angle AR2 (step S23), it is determined that the bucket 6 has reached the position separated from the driving unit 15 by the second predetermined distance, and FIG. , The pilot pressure of the pilot valve 32a is unloaded by the pressure control valve 42, and the operation of the arm 5 toward the scraping side (extension operation of the hydraulic cylinder 12) irrespective of the operation position of the rear operation of the left operation lever 10 Is suppressed (step S26).

Conversely, when the left operating lever 10 is operated forward to change the front-rear angle a3 of the arm 5 to the earth discharging side (when the front-rear angle a3 of the arm 5 increases) (step S1).
7) Since the bucket 6 is separated from the driving unit 15, a pilot pressure corresponding to the operation position of the left operation lever 10 at the previous operation is generated, and the speed corresponding to the operation position of the left operation lever 10 at the previous operation is generated. , The arm 5 is operated to the earth discharging side (step S27).

[8] As described in the above item [7], the first and second set angles AR1 and AR2 calculated by the relational expressions fa1 and fa2 in step S18 are determined by the vertical angle a1 and the first angle b1 of the first boom 4a. When the left / right angle a2 of the second boom 4b changes, the angle changes accordingly. For example, as the vertical angle a1 of the first boom 4a decreases, the second boom 4
The first and second set angles AR1 and AR2 decrease as the left-right angle a2 of b increases.

Thus, the vertical angle a of the first boom 4a
When the position of the bucket pin 6a when the front-rear angle a3 of the arm 5 reaches the first set angle AR1 corresponding to the left-right angle a2 of the first and second booms 4b is connected, FIGS.
And the locus B1 as described in the preceding section [5]. When the position of the bucket pin 6a when the front-rear angle a3 of the arm 5 reaches the second set angle AR2 corresponding to the vertical angle a1 of the first boom 4a and the left-right angle a2 of the second boom 4b, The trajectory A1 described in FIGS.

As described in FIG. 5 and the preceding section [5], the second
When the left-right angle a2 of the boom 4b exceeds a predetermined angle (in the configuration shown in FIG. 5, the state in which the first and second booms 4a and 4b are in a straight line and the second boom 4b is located on the right swing side), Since the bucket 6 is separated to the right side from the operation unit 15, even if the arm 5 is operated to the scraping side and the earth discharging side in this state, the bucket 6 is moved to the operation unit 15 (vertical and upper partition plate 1).
6, 17). Thus, when the left-right angle a2 of the second boom 4b becomes larger than the above-described predetermined angle, the first and second set angles AR1 and AR2 calculated by the relational expressions fa1 and fa2 in step S18 become sufficiently small values ( (Small value exceeding the limit of the squeezing of the arm 5) so that the arm 5 can be operated to the limit of the squeezing.

When the arm 5 is about to be operated to the squeezing limit, when the front-rear angle a3 of the arm 5 reaches the fourth set angle AR4 slightly before the squeezing limit (step S).
19), the pilot pressure of the pilot valve 32a is reduced by the pressure control valve 42 shown in FIG. 3, and the operation of the arm 5 to the scraping side (the hydraulic cylinder) is performed regardless of the operation position of the rear operation of the left operation lever 10. (The extension speed of the cylinder 12) is decelerated (step S20), and when the arm 5 reaches the scraping limit, the relief valve 45 shown in FIG. 2 is opened, and the arm 5 (the hydraulic cylinder 12) stops. When the left and right angle a2 of the second boom 4b has reached the above-mentioned predetermined angle, when the arm 5 is operated to the scraping side and the earth discharging side,
When the positions of the bucket pins 6a are connected, a locus A2 as described in FIG. 5 and the preceding section [5] is obtained.

[9] Next, control when the second boom 4b is operated to the left swing side and the right swing side will be described with reference to FIG. As described in the preceding section [4], the detection value of the boom vertical angle sensor 36 (the vertical angle a of the first boom 4a)
1) The values detected by the boom left / right angle sensor 37 (the left / right angle a2 of the second boom 4b) and the arm front / rear angle sensor 38 (the front / rear angle a3 of the arm 5) are constantly input to the control device 40 (step S1). ).

When the operation pedal 39 is depressed to the left and the second boom 4b is operated to the left swing side, the bucket 6 is driven by the driving unit 1
5 is approached. Thereby, the operation pedal 39
Is operated to the left to change the left / right angle a2 of the second boom 4b to the left swing side (the left / right angle a of the second boom 4b).
2 decreases (step S28), the vertical angle a1 of the first boom 4a and the front-rear angle a of the arm 5 at this time.
3, the first set angle OF1 and the second set angle OF2 are calculated from the relational expressions fo1 and fo2 (step S29).

In this case, the left-right angle a2 of the second boom 4b
Does not reach the first set angle OF1 (step S
32), it is determined that the bucket 6 is still at a position sufficiently far from the operation unit 15, and a pilot pressure corresponding to the operation position of the operation pedal 39 is generated, and the bucket 6 is driven at a speed corresponding to the operation position of the operation pedal 39. The second boom 4b is operated to the left swing side (step S33).

Next, the left-right angle a2 of the second boom 4b is equal to the first angle.
When the angle exceeds the set angle OF1 (steps S32, S3
4), it is determined that the bucket 6 has approached the driving unit 15 beyond the position separated by the first predetermined distance from the driving unit 15,
The difference Δa2 between the left / right angle a2 of the second boom 4b and the first set angle OF1 is calculated (Step S35). As a result, the pilot pressure of the pilot valve 35a is reduced by the pressure control valve 43 shown in FIG. 3 based on the difference Δa2, and the left boom of the second boom 4b is irrespective of the operation position of the left pedal operation of the operation pedal 39. The operation to the moving side (the extension speed of the hydraulic cylinder 7) is decelerated, and the larger the difference Δa2 (the closer the bucket 6 approaches the driving unit 15), the more the left boom 4b of the second boom 4b moves. Is greatly decelerated (step S).
36).

Next, the left-right angle a2 of the second boom 4b is equal to the second angle.
When the set angle OF2 is reached (step S34), it is determined that the bucket 6 has reached a position separated by a second predetermined distance from the operating unit 15, and the pilot pressure of the pilot valve 35a is increased by the pressure control valve 43 shown in FIG. Unloaded,
Regardless of the operation position of the left pedal operation of the operation pedal 39, the operation of the second boom 4b to the left swing side (extension operation of the hydraulic cylinder 7) is prevented (step S37).

On the contrary, when the operation pedal 39 is depressed rightward,
When the left / right angle a2 of the second boom 4b changes to the right swing side (when the left / right angle a2 of the second boom 4b increases)
(Step S28) Since the bucket 6 is separated from the operation unit 15, a pilot pressure corresponding to the operation position of the right pedal operation of the operation pedal 39 is generated, and the operation pedal 3
The second boom 4b is operated to the right swing side at a speed corresponding to the operation position of the right depressing operation 9 (step S38) (FIG. 3).
As shown in FIG. 7, the pressure control valve 43 is not provided in the pilot oil passage of the pilot valve 35b of the operation pedal 39).

[10] As described in [9] above, the first and second set angles OF1 and OF2 calculated by the relational expressions fo1 and fo2 in step S29 are equal to the vertical angle a1 of the first boom 4a and the arm When the front-back angle a3 of 5 changes,
It changes with this. When the bucket 15 is located in front of the driving unit 15, the first and second set angles OF1 and OF2 are set such that the vertical angle a1 of the first boom 4a increases and the longitudinal angle a3 of the arm 5 increases. Become smaller. The vertical angle a1 of the first boom 4a and the arm 5 such that the bucket 15 is located on the right side of the driving unit 15
, The first and second set angles OF1,
OF2 becomes a constant value.

Thus, when the bucket 15 is located in front of the driving section 15, the second boom 4b is moved in accordance with the vertical angle a1 of the first boom 4a and the front-rear angle a3 of the arm 5.
When the position of the bucket pin 6a is connected when the left / right angle a2 of the left side reaches the first set angle OF1, a locus B1 as described in FIGS. Corresponding to the vertical angle a1 of the first boom 4a and the front-back angle a3 of the arm 5, the left-right angle a2 of the second boom 4b is set to the second set angle O.
When the positions of the bucket pins 6a at the time of reaching F2 are connected, a trajectory A1 as described in FIGS.
Becomes

When the bucket 15 is located on the right side of the driving section 15, when the position of the bucket pin 6a when the left-right angle a2 of the second boom 4b reaches the first set angle OF1 is connected, FIG. And trajectory B as described in the preceding section [5]
It becomes 2. Vertical angle a1 of first boom 4a and arm 5
When the position of the bucket pin 6a when the left-right angle a2 of the second boom 4b reaches the second set angle OF2 corresponding to the front-rear angle a3 of FIG. The trajectory A2 results.

If the bucket 6 is located at a position sufficiently distant from the driving section 15 forward (the state in which the first boom 4a is operated to the lowering side and the arm 5 is operated to the earth discharging side), in this state, Even if the second boom 4a is operated to the left swing limit, the bucket 6 is driven by the driving unit 15 (vertical and upper partition plates 16, 17).
Never touch. Accordingly, when the bucket 6 is located at a position sufficiently distant forward from the driving unit 15, the first and second set angles OF1 and OF2 calculated by the relational expressions fo1 and fo2 in step S29 are sufficiently small. The value is set to a value (a small value exceeding the left swing limit of the second boom 4b), and the second boom 4b can be operated to the left swing limit.

When the second boom 4b is to be operated to the left swing limit, when it reaches the third set angle OF3 slightly before the left swing limit of the second boom 4b (step S3).
0), the pilot valve 3 is controlled by the pressure control valve 43 shown in FIG.
When the pilot pressure of 5a is reduced, the operation pedal 39 is operated.
Irrespective of the operation position of the left depressing operation, the operation of the second boom 4b to the left swing side (the extension speed of the hydraulic cylinder 7) is decelerated (step S31).
When b reaches the left swing limit, the relief valve 45 shown in FIG. 2 opens, and the second boom 4b (the hydraulic cylinder 7) stops.

[First Embodiment of the Invention] In step S15 described in FIG. 6 and the preceding paragraph [6], instead of operating the arm 5 to the earth discharging side at a low speed (operating to contract the hydraulic cylinder 12), The operation of the arm 5 on the squeezing side (the extension speed of the hydraulic cylinder 12) may be reduced, or the operation of the arm 5 on the squeezing side may be prevented from being restrained. Even with such a configuration, the state in which the bucket 6 approaches the operating unit 15 can be avoided, similarly to the case where the arm 5 is operated to the discharging side at a low speed (the contraction operation of the hydraulic cylinder 12).

Step S described in FIG. 6 and the preceding section [6]
6, In S14, when the front-rear angle a3 of the arm 5 exceeds the third set angle AR3, the arm 5 is not immediately operated at a low speed toward the earth discharging side (the contraction operation of the hydraulic cylinder 12), but the front-rear direction of the arm 5 is set. The arm 5 may be operated at a low speed toward the earth discharging side (the contraction operation of the hydraulic cylinder 12) after a lapse of a set time after the angle a3 exceeds the third set angle AR3.

Step S described in FIG. 6 and the preceding section [6]
6, In S14, when the front-rear angle a3 of the arm 5 exceeds the third set angle AR3, when the arm 5 is immediately operated to the earth discharging side at a low speed (the contraction operation of the hydraulic cylinder 12),
When the bucket pin 6a reaches the locus B1 shown in FIGS. 4 and 5, the arm 5 is operated at a low speed toward the earth discharging side (the hydraulic cylinder 12).
, The third setting angle AR3 may be set by the relational expression fa3 in step S3. Step S1 described in FIG. 6 and the preceding section [6]
5, the speed at which the arm 5 is operated to the discharging side at a low speed (the contraction operation of the hydraulic cylinder 12) can be changed slightly to a higher speed side or further changed to a lower speed side. You may.

[Second Alternative Embodiment of the Invention] In the aforementioned [Embodiment of the Invention] and [First Embodiment of the Invention], a bucket longitudinal angle sensor (not shown) is provided at the position of the bucket pin 6a. And the front-rear angle of the bucket 6 is also shown in FIG.
And the relational expressions fb1, fb2, fa1, fa shown in FIG.
2, fa3 as parameters,
The configuration may be such that the set angles BO1, BO2, AR1, AR2, AR3 are calculated.

The operating positions of the right and left operating levers 9 and 10 and the operating pedal 39 are electrically detected by a potentiometer (not shown), and a pilot valve (not shown) of an electromagnetic proportional pressure reducing valve type is operated. The type of operation of the pilot-type control valves 21 to 25 and the operation positions of the right and left operation levers 9 and 10 and the operation pedal 39 are electrically detected by a potentiometer (not shown), and electromagnetically detected based on the detected values. The present invention is also applicable to a type in which a control valve (not shown) of a proportional pressure reducing valve type is operated. Furthermore, the present invention is also applicable to a backhoe in which the driving unit 15 is disposed on the right side of the swivel base 2 and the boom 4 (first boom 4a) of the backhoe device 3 is disposed on the left side of the swivel base 2.

[0079]

According to the first aspect of the present invention, when the backhoe is configured to avoid the contact of the bucket with the driving section, the triangular function is used to determine the XYZ position of the bucket.
Even without calculating the coordinates, it is properly determined that the bucket has reached a position a predetermined distance away from the operation unit by operating the arm to the rake side based on the vertical angle of the boom and the front-back angle of the arm. The operation of the arm on the rake side can be prevented from being restrained. As described above, according to the first aspect of the present invention, it is possible to avoid contact of the bucket with the operating unit due to the operation of the arm on the scraping side without calculating the XYZ coordinates of the bucket position using the trigonometric function. As a result, the load on the arithmetic unit can be reduced.

According to the first aspect of the present invention, when the operation of raising the boom and the operation of moving the arm to the scraping side are performed simultaneously, the arm is automatically moved to the earth discharging side (or By configuring so that the operation of the arm on the squeezing side is automatically prevented from being restrained (or the operation of the arm on the squeezing side is automatically decelerated),
The bucket can be prevented from rapidly approaching the driving unit, and the workability of the backhoe can be improved.

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, and in addition to the "effect of the invention", the following "invention" is provided. Of the effect. According to the feature of claim 2, the bucket is operated by the upward movement of the boom based on the vertical angle of the boom and the front-rear angle of the arm without calculating the XYZ coordinates of the position of the bucket using a trigonometric function. By appropriately determining that the vehicle has reached a position a predetermined distance away from the driving unit, it is possible to prevent the operation of the boom on the ascending side from checking. Thus, according to the features of claim 2,
Even without using the trigonometric function to calculate the XYZ coordinates of the position of the bucket, it is possible to avoid contact of the bucket with the driving section due to the operation of raising the boom,
The load on the arithmetic unit can be reduced.

According to the second aspect of the present invention, when the operation of raising the boom and the operation of moving the arm to the scraping side are simultaneously performed, the arm is automatically moved to the earth discharging side. Since the operation of the arm on the squeezing side is prevented from restraining (or the operation of the arm on the squeezing side is automatically decelerated), the operation of the boom on the rising side and the squeezing of the arm are performed. When the operation to the side is performed at the same time, the state where the detection value of the boom vertical angle sensor reaches the set value with respect to the detection value of the arm front and rear angle sensor and the operation of the boom ascending side can not be performed can be avoided. Like that,
The workability of the backhoe was further improved.

According to the feature of claim 3, claim 1 or 2
"Effects of the Invention" of Claim 1 or 2 as in the case of
In addition to this “effect of the invention”, the following “effect of the invention” is provided. According to the feature of claim 3, when the operation of raising the boom and the operation of moving the arm to the scraping side are performed simultaneously, the arm is operated to the earth discharging side after the lapse of the set time. Since the operation of the arm on the squeezing side is stopped after the lapse of time (because the operation of the arm on the squeezing side is decelerated after the lapse of the set time), the bucket rises near the front of the driving unit. As a result, it is possible to avoid a situation in which the operator of the driving unit feels uncomfortable.

According to the features of claim 4, the "effects of the invention" of the claims 1 to 3 are provided similarly to any one of the claims 1 to 3, and the "effects of the invention" are included in the "effects of the invention". In addition, it has the following "effects of the invention". According to the feature of claim 4, the operation of raising the boom and the operation of scraping the arm are performed simultaneously, and the arm is automatically moved to the earth discharging side (or the arm is automatically moved). When the operation on the squeezing side is prevented from being restrained (or when the operation on the squeezing side of the arm is automatically decelerated), the operation on the ascending side of the boom is decelerated. As a result, the state in which the bucket rapidly approaches the driving unit can be further suppressed, and the workability of the backhoe can be further improved.

According to the feature of the fifth aspect, similar to the case of the fourth aspect, the present invention has the above-mentioned "effect of the invention" of the fourth aspect. Of the effect. According to the feature of claim 4, the operation of raising the boom and the operation of scraping the arm are performed simultaneously, and the arm is automatically moved to the earth discharging side (or the arm is automatically moved). When the operation on the squeezing side is prevented from restraining (or when the operation on the squeezing side of the arm is automatically decelerated), the vertical angle of the boom approaches the angle at which the boom stands upright on the swivel. As a result, the operation of the boom on the ascending side is greatly decelerated, and the state in which the bucket rapidly approaches the driving unit is further suppressed, so that the workability of the backhoe can be further improved.

[Brief description of the drawings]

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

FIG. 2 is a hydraulic circuit diagram showing a hydraulic cylinder, a control valve, and the like of the 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.

4 is a side view showing trajectories connecting the positions of bucket pins in steps S11 and S12 in FIG. 6 and steps S25 and S26 in FIG. 7;

FIG. 5 is a plan view showing trajectories connecting positions of bucket pins in steps S11 and S12 in FIG. 6, steps S25 and S26 in FIG. 7, and steps S36 and S37 in FIG.

FIG. 6 is a diagram showing a control flow when the first boom is operated to the ascending side and the descending side.

FIG. 7 is a diagram showing a control flow when the arm is operated to the scraping side and the earth discharging side.

FIG. 8 is a diagram showing a control flow when the second boom is operated to the left swing side and the right swing side.

[Explanation of symbols]

 2 Swivel base 4 Boom 5 Arm 6 Bucket 15 Operating part 36 Boom vertical angle sensor 38 Arm longitudinal angle sensor AR2 Set value BO2 Set value a1 Vertical angle a3 Front / rear angle

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Atsushi Matsumoto 64, Ishizukita-cho, Sakai-shi, Osaka F-term in Kubota Sakai Works Co., Ltd. (Reference) 2D003 AA01 AB02 AB03 AB04 BA02 BA03 BA07 BB07 BB11 CA02 DA03 DA04 DB04 DC04

Claims (5)

[Claims] 1. A boom supported on a revolving base so as to be vertically swingable, an arm supported on a tip of the boom so as to be able to swing back and forth, and a bucket supported on a tip of the arm. A boom vertical angle sensor for detecting a vertical angle of the boom with respect to the table, and an arm front and rear angle sensor for detecting a vertical angle of the arm with respect to the boom, and the arm front and rear angle sensor with respect to a detection value of the boom vertical angle sensor When the detected value reaches a set value, it is determined that the bucket has reached a position separated by a predetermined distance from the operating unit, and an arm restraining means for restraining the operation of the arm on the scraping side is provided. When the detection value of the boom vertical angle sensor changes to the rising side and the detection value of the arm front-rear angle sensor changes to the scraping side, the arm moves to the earth discharging side. A backhoe provided with arm control means for operating the arm, the operation of the arm on the squeezing side is suppressed, or the operation of the arm on the squeezing side is decelerated. . 2. When the detected value of the boom vertical angle sensor reaches a set value with respect to the detected value of the arm front-rear angle sensor, it is determined that the bucket has reached a position separated from the driving unit by a predetermined distance. And a boom restraint means for restraining the upward movement of the boom from being restrained.
The described backhoe. 3. When the detection value of the boom vertical angle sensor changes to an ascending side and the detection value of the arm front-rear angle sensor changes to a scraping side, the arm control means starts operating after a lapse of a set time. 3. The backhoe according to claim 1, wherein said arm control means is configured. 4. A boom speed reduction means for decelerating the operation of the boom to the rising side when the detection value of the boom vertical angle sensor changes to the rising side and the detection value of the arm front and rear angle sensor changes to the scraping side. Claims 1 to
The backhoe according to any one of the three. 5. An operation in which the operation of the boom ascending side is greatly decelerated as the detection value of the boom vertical angle sensor approaches the angle at which the boom stands upright on the swivel base.
5. The backhoe according to claim 4, wherein said boom speed reduction means is constituted.