JP2624391B2 - Backhoe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety structure for a worker who is sitting on a driving unit in a backhoe.

[0002]

2. Description of the Related Art An example of a safety structure for a driving unit in a backhoe is disclosed in Japanese Patent Application Laid-Open No. 2-256722. In this structure, a danger surface (corresponding to the second set position in FIG. 3 of the above-mentioned publication) which is outwardly separated from the outermost portion of the driving unit by a predetermined distance, and a range of the set distance outward from the danger surface (Corresponding to the deceleration range in FIG. 3 of the above-mentioned publication) is set on the space. A speed sensor for detecting the position of the bucket of the backhoe device, a speed reducing means for automatically reducing the speed of the backhoe device when the bucket enters the deceleration region based on the detection of the position sensor, and When the bucket attempts to enter the operation section side beyond the danger surface, a hydraulic brake cylinder for driving the backhoe device is stopped to prevent the hydraulic cylinder from restraining the hydraulic cylinder.

[0003] In the above configuration, even if the operator of the driving section operates the backhoe device and accidentally moves the bucket to the driving section side to a close distance, the bucket enters the deceleration area. For example, the backhoe device is automatically decelerated, and when the bucket reaches the danger surface, the backhoe device is automatically stopped, so that the bucket is not too close to the worker, which is convenient.

[0004]

In the above-described structure, no particular danger surface and deceleration area are set in the range below the driving unit, so that the bucket is moved from the driving unit to a short distance from the traveling device in the range below the driving unit. Excavation work can be performed in close proximity. However, when the bucket is brought close to the traveling device and the soil is scraped off, if the bucket is lifted as it is, the bucket enters the inside of the above-mentioned danger surface (driving unit side) from below. In some cases, the check means operates and the backhoe device stops at that position.

[0005] In view of this, it is conceivable to extend the above-mentioned danger surface and deceleration area set from the driving section to the ground directly below. If the deceleration operation is performed by the action, the excavation force is also reduced, so that excavation cannot be performed well.

[0006] It is an object of the present invention to provide a construction in which excavation work can be performed without hindrance while ensuring safety such as deceleration and stoppage of a backhoe device near an operation unit.

[0007]

The feature of the present invention resides in the following configuration of the above-mentioned backhoe. That is, in a range above the predetermined position near the lower part of the driving unit, a danger surface set in a space separated by a predetermined distance outward from the outermost portion of the driving unit, and a predetermined distance outward from the danger surface. A first restriction area is formed by the deceleration area set up to the distant space, and at a position away from the traveling device by a predetermined distance, connected to a lower portion of the danger surface, and A second restriction area is formed at a boundary surface that does not include a deceleration area, and the first restriction is performed during the approach operation of the bucket to the operation unit side based on a detection result of a position sensor that detects a position of a bucket of a backhoe device. When it is determined that the range has been reached, the hydraulic cylinder for the backhoe device is decelerated in the deceleration region, the hydraulic cylinder is stopped on the danger surface, and the position of the bucket of the backhoe device is detected. The bucket based on the detection result of the Nsa is provided with a restraining means for stopping the hydraulic cylinder at the boundary surface and that reaches the second regulation zone in the approaching operation is determined to traveling device side.

[0008]

According to the above-mentioned feature, for example, as shown in FIG. 1, since the danger surface A1 and the deceleration area B1 are set in a range above a predetermined position D near the lower part of the driving unit, the bucket 6 is set to the driving unit. When the bucket 6 (bucket pin 6a in the configuration of FIG. 1) reaches the first restriction region R1 during the operation of approaching, the restraint means automatically decelerates the hydraulic cylinders 7, 11, 12 of the backhoe device 3 in the deceleration region B1. Further, the restraint means automatically stops the hydraulic cylinders 7, 11, and 12 of the backhoe device 3 at the danger surface A1, and the phenomenon that the bucket 6 goes over the danger surface A1 and enters the operation unit side is prevented. Will be.

[0009] Since only the boundary surface E is set in the second regulation region R2 formed below the first regulation region R1 with reference to the traveling device 1, the bucket 6 is operated when the bucket 6 approaches the traveling device 1. 6 (bucket pin 6a in the configuration of FIG. 1) reaches the second restriction region R2, and the restraint means moves the hydraulic cylinders 7, 1 of the backhoe device 3 at the boundary surface E.
1 and 12 are automatically stopped, and the phenomenon that the bucket 6 enters the traveling device 1 beyond the boundary surface E without being decelerated until reaching the boundary surface E is prevented. .

That is, when the bucket 6 is moved closer to the operation unit 27 at a position higher than the predetermined position D, the bucket 6 is automatically stopped after automatic deceleration, so that no shock is generated and the bucket 6 is operated without any shock. For example, during the work of excavating the ground near the traveling device, the bucket 6 is not decelerated until it reaches the boundary surface E, so that the bucket 6 is operated in a non-decelerated state to enable the work. In addition, the work can be performed without deceleration below the predetermined position D at a position outside the boundary surface E with respect to the traveling device 1 at a position outside the boundary surface E.

[0011]

As described above, by setting only the boundary surface without providing a deceleration area in a range below the driving section, sufficient excavation work can be performed without a decrease in excavation force due to deceleration. The workability of excavation was improved. Then, when the bucket is lifted by scraping the soil on the ground near the traveling device, the bucket can be raised as it is without the bucket entering the inside of the upper danger surface and stopping the backhoe device. As a result, good operability can be obtained.

In the range above the driving unit, a deceleration operation is performed by the bucket entering the deceleration region, and a check operation is performed to prevent the operation unit from operating the bucket beyond the danger surface. Safety is ensured as in the conventional configuration.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 shows the entire side surface of the backhoe. A traveling device 1 of rubber crawler type supports a dozer 20 and a swivel 2 above the dozer 20. A backhoe 3 is provided at the front of the swivel 2. The backhoe device 3 includes a boom 4 which is vertically driven to swing by a hydraulic cylinder 11, an arm 5 which is driven to swing back and forth by a hydraulic cylinder 12, and a bucket 6 which is driven to be swung and swung by a hydraulic cylinder 13. It is configured. As shown in FIG. 3, a hydraulic motor 14 is provided for driving the turntable 2 to turn.

The boom 4 of the backhoe 3 is shown in FIG.
As shown in FIG. 2, the second boom 4b is swingably connected around the axis P1 at the front end of the first boom 4a, which is driven to swing up and down, and around the axis P2 at the front end of the second boom 4b. The support bracket 4c is swingably connected, and the arm 5 is connected to the support bracket 4c. A link 4 is erected between the first boom 4a and the support bracket 4c to form a parallel quadruple link. The hydraulic cylinder 7 drives the second boom 4b to swing, so that the arm 5 and the bucket 6 are moved. Can be moved left and right in parallel.

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

As shown in FIGS. 3 and 5, the swivel 2 is provided with a right operating lever 9 and a left operating lever 10.
The right and left operation levers 9 and 10 are freely operable back and forth and left and right, and are provided with a potentiometer 15 for detecting a front and rear operation position of the right operation lever 9 and a potentiometer 16 for detecting a left and right operation position. A potentiometer 17 for detecting the operation position of the operation lever 10 in the front-rear direction and a potentiometer 18 for detecting the operation position in the left-right direction are provided. Operation signals from the potentiometers 15 to 18 are input to the control device 19. An operation pedal 26 is provided at a lower portion of the front portion of the swivel base 2, and an operation signal from the operation pedal 26 is input to the control device 19.

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

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

As shown in FIG. 5, a potentiometer 36 (corresponding to a position sensor) for detecting the vertical angle of the boom 4 (first boom 4a), and a potentiometer 37 (corresponding to the position sensor) for detecting the left / right angle of the second boom 4b. ) And a potentiometer 38 for detecting the front-rear angle of the arm 5
(Corresponding to a position sensor), and detection signals from the potentiometers 36, 37, 38 are input to the control device 19.

Then, the boom 4, the second boom 4b and the arm 5 are moved to the right and left operation levers 9, 10 and the operation pedal 26.
When the potentiometers 36, 37, and 38 detect that the hydraulic cylinders 11, 7, and 12 of the boom 4, the second boom 4b, and the arm 5 have reached a position slightly short of their stroke ends in a state in which Pilot valves 31a, 31b, 35a, 35b, irrespective of the operating positions of right and left operating levers 9, 10 and operating pedal 26.
The pilot pressures of 32a and 32b are automatically reduced,
The hydraulic cylinders 11, 7, and 12 are configured so that the expansion / contraction speed is automatically reduced.

As shown in FIGS. 1 and 2, in the swivel 2, a backhoe device 3 is disposed on the right side, and a driving section 27 including a driver's seat 28 and right and left operation levers 9 and 10 is provided on the left side. Are located. And the vertical partition board 29 with a window which partitions the backhoe apparatus 3 and the driving | running part 27 in the center of right and left of the swivel 2 (equivalent to the outermost part of the driving part 27).
A semicircular upper partition plate 30 (corresponding to the outermost portion of the operation unit 27) is fixed to the upper end of the vertical partition plate 29 along the outside of the swivel 2. Then, in a range above a predetermined position D near the lower part of the driving unit 27 at a predetermined height from the ground G, a front danger surface A1 separated from the front end surface of the vertical partition plate 29 by a predetermined distance forward (outward), and A dangerous lateral surface A2 that is separated from the side surface of the vertical partition plate 29 on the backhoe device 3 side by a predetermined distance to the right (outward) is set in the control device 19.

In this case, a bucket pin 6a (see FIG. 1) connecting the bucket 6 to the tip of the arm 5 moves the bucket 6 closest to the operation unit 27 while the bucket pin 6a is on the front danger surface A1. Even if the above operation is performed, the front danger surface A1 is set so that the tip of the bucket 6 is located on the locus C1 separated from the driving unit 27 by a predetermined distance. In addition, as shown in FIG. 2, with the bucket pin 6a on the lateral danger surface A2, the lateral danger is set so that the lateral side of the bucket 6 is on the locus C2 separated from the vertical partition plate 29 by a predetermined distance. The plane A2 is set.

The front and side danger planes A1 and A2 are set to have planes separated by a predetermined distance forward or rightward from the danger planes A1 and A2. The deceleration area B2 is set in the control device 19.
The first restriction region R1 is formed by each of the region formed by the front danger surface A1 and the front deceleration region B1, and the region formed by the side danger surface A2 and the horizontal deceleration region B2.

When excavating the ground G from the backhoe device 3, the mechanical operation limit of the backhoe device 3 itself, which indicates how close the backhoe device 3 can excavate to the traveling device 1, is determined in advance. I have. Then, it is calculated which trajectory the bucket pin 6a passes when operated to the operation limit. As shown in FIG. 1, it is set in the control device 19 in a range below the predetermined position D. And
The boundary surface E is set so as to be smoothly connected to the front danger surface A1, and when the bucket 6 is operated so as to be closest to the traveling device 1 when the bucket pin 6a is on the boundary surface E, the bucket 6 The tip passes on the locus C3. Then, at this boundary surface E, the second regulation area R
2 are formed.

The front and side danger surfaces A1, A2,
The front and side deceleration areas B1, B2 and the boundary surface E are set with respect to the swivel 2 and move with the swivel 2 as the swivel 2 rotates. .

In the control device 19, the vertical angle of the boom 4 (first boom 4a), the horizontal angle of the second boom 4b, the front-rear angle of the arm 5, and the first boom 4a , 2nd boom 4
The position of the bucket pin 6a is constantly calculated from b and the length of the arm 5. When the bucket pin 6a enters the front of the first restriction region R1 and the lateral deceleration regions B1 and B2 shown in FIGS. 1 and 2, the pilot valves 31a to 32
b, 35a, 35b to operate the right and left operation levers 9,
10. Regardless of the operation of the operation pedal 26, the speed of the hydraulic cylinders 11, 12, and 7 of the backhoe device 3 is reduced. In this case, as the bucket pin 6a enters the front and lateral deceleration regions B1 and B2, that is, the bucket pin 6a
Is configured to perform a large deceleration operation as the vehicle approaches the front and lateral danger surfaces A1 and A2.

Then, when the bucket pin 6a is in the first regulation region R
When the bucket pins 6a are positioned on the front and side danger surfaces A1 and A2, the bucket pins 6a
When the backhoe device 3 is operated in a direction away from the first and A2, the front and side deceleration areas B
The speed of each of the hydraulic cylinders 11, 12, 7 is increased in 1 and B2, and is returned to the normal speed when the vehicle comes out of the front and lateral deceleration regions B1 and B2. Conversely, if the bucket pin 6a is to be operated toward the operation unit 27 beyond the front and side danger surfaces A1, A2 even slightly from the front and side danger surfaces A1, A2, the pilot valves 31a to 32b, 3
The pilot pressure of 5a and 35b disappears and the control valves 21 and
2, 25, the hydraulic cylinder 11,
12 and 7 are stopped.

When the bucket pin 6a is located in front of the first restriction region R1 and on the side danger surfaces A1 and A2, the operation of the hydraulic cylinder 13 of the bucket 6 can be performed. An operation of moving on the planes A1 and A2 can be performed at an extremely low speed.

As described above, the front and lateral deceleration areas B1 and B2 are set in the portion above the predetermined position D shown in FIG. The lateral deceleration areas B1 and B2 are not set. Therefore, until the bucket pin 6a reaches the boundary surface E, the hydraulic cylinders 11, 12, 13, 7 of the backhoe device 3 are operated at a speed based on the operation of the right and left operation levers 9, 10 and the operation pedal 26. You. When the bucket pin 6a is slightly operated beyond the boundary surface E toward the traveling device 1, the pilot valves 31a to 3a
2b, 35a, 35b pilot pressure disappears and control valve 2
The hydraulic cylinders 11, 12, and 7 of the backhoe device 3 are stopped by 1, 2, and 25.

When the bucket pin 6a is located on the boundary surface E, the operation of the hydraulic cylinder 13 of the bucket 6 can be performed, and an operation such that the bucket pin 6a moves on the boundary surface E can also be performed. Therefore, when the bucket 6 scrapes off the soil on the ground G near the traveling device 1, the bucket 6 may be lifted so that the bucket pin 6a moves upward on the boundary surface E. In this way, the bucket pin 6a smoothly moves from the boundary surface E to the front danger surface A1, enters the front deceleration region B1, and the backhoe device 3 is decelerated as described above. As described above, the bucket 6 in the deceleration areas B1 and B2 of the first regulation area R1 is used.
Of the first regulation area R1, the danger surface A1,
At A2, control to stop the operation of the bucket 6 toward the driving unit 27 is performed, and at the boundary surface E of the second restriction region R2, the traveling device 1 is controlled.
The control device 19 for controlling the operation of the bucket 6 to the side of the stop is configured as a check means.

Next, the flow of setting the front and side danger surfaces A1, A2, etc. when the key switch (not shown) is turned ON will be described. As shown in FIG.
7, a push button type first switch 39 is arranged beside the driver's seat 28, and an ON / OFF switching holding type second switch 39 is provided inside a door (not shown) below the driver's seat 28.
A switch 40 is provided. And the first and second
The switches 39 and 40 are connected in parallel so that a signal is input to the control device 19.

As shown in FIG. 4, when the key switch is turned on to start the engine (not shown), the second switch 40 is turned off (step S).
1) If the first switch 39 is not pressed (step S2), as described above, the front and side danger surfaces A1, A2,
The front and side deceleration areas B1 and B2 and the boundary surface E are set (step S3), and a state where the deceleration operation and the check operation of the backhoe device 3 are performed as usual is brought about. Then, a deceleration operation is performed when the hydraulic cylinders 11, 7, 12 of the boom 4 (the first boom 4a), the second boom 4b, and the arm 5 reach their stroke ends (step S4).

If normal signals are not input from the potentiometers, sensors, and the like to the control device 19 during the operation in the normal state as described above, it is determined that an abnormality has occurred and the backhoe device 3 is stopped (step S5). , S
6).

When the operator of the operation unit 27 presses the first switch 39 during this normal operation and this signal is input to the control unit (step S2), the inside of the operation unit 27 and the operation unit The danger avoidance release lamps (not shown) at two places outside of the lamp 27 are turned on (step S7). In this state, the front and side danger surfaces A1 and A2, the front and side deceleration areas B1 and B2, and the boundary surface E are erased (step S8), and thus the deceleration operation and the check operation of the backhoe device 3 as described above. Is not performed, and the worker can perform the work by approaching the bucket 6 to the driving unit 27, the traveling device 1, and the like to a close distance while sufficiently checking the safety.

In this case, the boom 4 (first boom 4a)
The deceleration operation when the stroke end is reached is performed only in the hydraulic cylinder 11 of this example, and such a deceleration operation is not performed on the other hydraulic cylinders 7 and 12 (step S9). . Further, even if a normal signal is not input to the control device 19 from each potentiometer, sensor, or the like, the backhoe device 3 can be operated.

If the first switch 39 is pressed (step S10) during the operation in a state where the deceleration operation and the stop operation are not performed as described above, the danger avoidance release lamp is turned off (step S11). , Step S3
It returns to the normal state again.

Before starting the engine, if it is known that a normal signal from each potentiometer, sensor, or the like is not input to the control device 19 due to disconnection or the like, the second switch 40 is operated before the key switch is operated. O
N operations are performed. In this way, the emergency operation lamp (not shown) is turned on after the key switch is turned on (step S12), and the process proceeds to step S8 to perform the above-described deceleration operation, stop operation, and each potentiometer operation. The operation of the backhoe device 3 can be performed irrespective of the state of the like.

[Alternative Embodiment] In the above embodiment, as shown in FIG. 1, the front and side danger surfaces A1 and A2 are set based on the position of the bucket pin 6a. A potentiometer is installed and the position of the tip of the bucket 6 is controlled by the control device 1.
9 may always be calculated. In this case, the trajectories C1 and C2 shown in FIG. 1 and FIG. 2 are dangerous surfaces of the present invention.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the accompanying drawings.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a backhoe showing a front danger surface, a front deceleration area, and a boundary surface.

FIG. 2 is a schematic plan view of a backhoe showing front and side danger surfaces and front and side deceleration areas.

FIG. 3 is a schematic circuit diagram of each hydraulic cylinder, control valve, pilot valve, right and left operating levers, first and second switches, etc. of the backhoe device.

FIG. 4 is a flowchart showing a control flow.

FIG. 5 is an overall side view of the backhoe.

[Explanation of symbols]

 Reference Signs List 1 traveling device 3 backhoe device 6 bucket of backhoe device 7, 11, 12 hydraulic cylinder for backhoe device 27 driving unit 29, 30 outermost portion of driving unit 36, 37, 38 position sensor A1, A2 dangerous surface B1, B2 deceleration Area D Predetermined position E Boundary plane R1 First regulation area R2 Second regulation area

Claims (1)

(57) [Claims] 1. A predetermined distance outwardly from outermost portions (29) and (30) of the driving portion (27) in a range above a predetermined position (D) near a lower portion of the driving portion (27).
Danger plane set in the space (A1), and (A2), this danger face (A1), Re away by a predetermined distance outwardly from (A2)
De deceleration region set up space (B1), and (B2)
A first regulating region (R1) and a traveling device (1);
At a predetermined distance outward from the
Connect to the lower part of planes (A1) and (A2) and outward
The boundary area (E) having no deceleration area and the second regulation area (R
2) forming the bucket (6) of the backhoe device (3)
Position sensors (36), (37),
Based on the detection result of (38), the bucket (6)
During the approach operation to the driving section (27) side, the first regulation area (R
1), it is determined that the deceleration area (B
In (1) and (B2), a hydraulic system for the backhoe device (3) is used.
Decelerate the Linders (7), (11) and (12)
The danger surface (A1), (A2) in the hydraulic cylinder (7),
(11), (12) is stopped, and a backhoe device
Position sensor for detecting the position of the bucket (6) of (3)
Based on the detection results of (36), (37) and (38),
The bucket (6) moves forward while approaching the traveling device (1).
If it is determined that the vehicle has reached the second regulation area (R2),
The hydraulic cylinders (7), (11),
A backhoe having a check means for stopping (12) .