JP2695340B2 - Backhoe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation structure of a backhoe device and a swivel base in a backhoe for excavation work.

[0002]

2. Description of the Related Art In the above-mentioned backhoe, a worker sitting on a driver's seat of a swivel generally operates a backhoe device and a swivel by operating an operating lever back and forth and right and left. .

[0003]

When excavating work with a backhoe in an urban area, demands for accuracy of excavation position have been increasing in recent years. This is because many types of pipes such as gas pipes, electricity and telephones are buried in urban areas, so when performing excavation work in this vicinity, it is necessary to perform excavation work without the bucket coming into contact with the pipes. Is.

However, in the above-mentioned backhoe, since the operator of the backhoe operates the backhoe device and the swivel base, the worker and the bucket are inevitably separated from each other. Therefore, when a worker on the swivel performs excavation work while visually observing the bucket and the pipe, it may be difficult to accurately bring the bucket to a desired excavation position. An object of the present invention is to configure a backhoe so that an accurate excavation work can be performed.

[0005]

[Means for Solving the Problems] In the backhoe,
As an operation structure of the backhoe device and the swivel base, there is a structure provided with the following pilot operation type configuration.
A hydraulic motor that drives the swivel base to rotate, a first hydraulic cylinder that swings the boom of the backhoe device up and down, a second hydraulic cylinder that swings the arm of the backhoe device, and a swing drive of the bucket of the backhoe device. 4 on the machine side that supplies and discharges hydraulic oil to and from each of the 3 hydraulic cylinders.
4 pilot-operated control valves and a pilot valve that generates pilot pressure based on the operating position of an operating lever provided in the control part of the swivel base are provided, and the pilot pressure from the pilot valves is 4 control valves. The backhoe is configured so that the four control valves can be operated by the pilot pressure based on the operation of the operation lever.

The present invention is characterized in that the pilot operated backhoe as described above is provided with the following configuration. An electromagnetically operated auxiliary pilot valve capable of supplying pilot pressure to the four control valves, and an operation section capable of electrically remotely operating the auxiliary pilot valve,
Supply the pilot pressure hydraulic oil from the pump to the pilot valve and not supply it to the auxiliary pilot valve Normal excavation work condition, and supply the pilot pressure hydraulic oil from the pump to the auxiliary pilot valve and not the pilot valve It is provided with a switching valve which can be selectively switched depending on the state of the remote excavation work.

[0007]

[I] According to the feature of claim 1 in the pilot operated type backhoe as described above, when the switching valve is switched to the normal excavation work state, the hydraulic oil for pilot pressure from the pump is piloted to the operating lever. It is supplied to the valve and is not supplied to the auxiliary pilot valve of the operation section described later. This allows
When the operator of the swivel operates the operation lever, the control valve is operated by the pilot pressure from the pilot valve of the operation lever, and the backhoe device and the swivel can be operated. It is in a state.

Next, it is assumed that a remote control operation unit 27 is provided as shown in FIG. 1, for example. In this case, if the switching valve is switched to the remote excavation work state, the hydraulic oil for pilot pressure from the pump is supplied to the auxiliary pilot valve of the operation portion 27 and not to the pilot valve of the operation lever. As a result, when a worker near the bucket 6 operates the operation unit 27, the electromagnetically operated auxiliary pilot valve is operated by the operation signal from the operation unit 27, and the pilot pressure from the auxiliary pilot valve of the operation unit is used. The control valve is operated,
The backhoe device 3 and the swivel base 2 can be operated. In this case, since the worker who operates the backhoe device 3 and the swivel base 2 is in the immediate vicinity of the bucket 6, this worker has a positional relationship between the bucket 6 and a desired excavation position (for example, a position where piping is avoided). Can be accurately grasped, and the bucket 6 can be accurately brought to a desired excavation position by operating the operation unit 27.

[II] According to the feature of claim 1, a normal excavation work state in which hydraulic oil for pilot pressure from the pump is supplied to the pilot valve of the operation lever and not to the auxiliary pilot valve of the operation portion,
And a switching valve that supplies the hydraulic oil for pilot pressure from the pump to the auxiliary pilot valve of the operation unit, and does not supply it to the pilot valve of the operation lever .

Thus, for example, when the switching valve is switched to the normal excavation work state and the operator of the swivel is operating the backhoe device and the swivel with the operation lever, the auxiliary pilot valve is erroneously operated by the operating portion. Even when operated, the control pilot valve is not operated by the auxiliary pilot valve of the operation unit because the pilot pressure hydraulic oil is not supplied to the auxiliary pilot valve of the operation unit. Therefore, a situation does not occur in which the operator operates the operation unit without being aware of the operator of the swivel platform, and the operator of the swivel platform unexpectedly operates the backhoe device and the swivel platform.

On the contrary, for example, when the switching valve is switched to the remote excavation work state and the operator beside the bucket is operating the backhoe device and the swivel base with the operation unit, the operating lever of the swivel base is erroneous. Even if the pilot valve of the operating lever is operated, the control valve is not operated by the pilot valve of the operating lever, because the pilot pressure hydraulic oil is not supplied to the pilot valve of the operating lever. Therefore, it is said that the operator operating the operation unit operates the operation lever of the swivel base without being aware of it, and the backhoe device and the swivel base are unexpectedly operated by the operator operating the operation unit. No situation occurs.

[III] In the recent backhoe, as described above, the pilot operation type in which the control valve of the backhoe device is a pilot operated type and the control valve is operated by the pilot pressure from the pilot valve of the operation lever is increasing. There is. Therefore, according to the feature of claim 1, by adding a hydraulic pressure switching valve for pilot pressure and an electromagnetically operated auxiliary pilot valve to an existing pilot operated type backhoe, it is only necessary to prepare a remote operated operation unit. The remote excavation work as described in the above section [I] can be carried out without any particular modification.

[0013]

According to the features of claim 1, the structure of the pilot-operated backhoe is effectively used, and the backhoe is configured to be capable of remote excavation work.
Accurate excavation work using the backhoe has made it possible to improve the workability of the backhoe in urban areas where many types of pipes are buried. The operation unit cannot operate the backhoe device and the swivel base while operating the backhoe device and the swivel base with the operation lever of the swivel base, and the operation of the swivel base when the backhoe device and the swivel base are operated by the operation unit By configuring the backhoe device and the swivel so that they cannot be operated by the lever, the backhoe device and the swivel are prevented from being inadvertently operated by a worker who operates the swivel and the operation unit. It was possible to prevent erroneous operations due to such unexpected operations. By adding a pilot pressure type hydraulic fluid switching valve and auxiliary pilot valve to the pilot operated backhoe, it can be converted to a backhoe that can be used for remote excavation work relatively easily without major modification. It is also advantageous in terms of.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the entire side surface of a backhoe, in which a swivel base 2 is supported above a traveling device 1 of a rubber crawler type, and a backhoe device 3 is provided in front of the swivel base 2. The backhoe device 3 includes a boom 4 and a second hydraulic cylinder 12 that are driven to swing up and down by a first hydraulic cylinder 11.
The arm 5 is driven to swing back and forth by the above, and the bucket 6 is swung and driven by the third hydraulic cylinder 13. The entire backhoe device 3 is swingably supported around the vertical axis P1 of the swivel base 2, and a fourth hydraulic cylinder 7 for swinging the backhoe device 3 is provided. A hydraulic motor 14 is provided to drive the swivel base 2.

Next, the hydraulic circuits of the swivel base 2 and the backhoe device 3 will be described. As shown in FIG. 2, the control valve 2 for supplying / discharging the hydraulic oil from the pump 33 driven by the engine 39 to / from the first hydraulic cylinder 11 of the boom 4.
1, a control valve 22 for supplying / discharging the second hydraulic cylinder 12 of the arm 5 and a control valve 23 for supplying / discharging the third hydraulic cylinder 13 of the bucket 6 are provided. A control valve 24 for supplying / discharging the hydraulic oil from another pump 33 to / from the hydraulic motor 14 of the swivel 2 and a control valve 25 for supplying / discharging operation to / from the fourth hydraulic cylinder 7 are provided. The control valves 21 to 25 are pilot-operated, and the opening of the control valves 21 to 25 is changed by changing the pilot pressure to adjust the flow rate of the hydraulic oil to change the operating speed of the first hydraulic cylinder 11 and the like. It can be operated.

As shown in FIGS. 1 and 2, the swivel base 2 includes a right operation lever 9 (corresponding to an operation lever) and a left operation lever 1.
0 (corresponding to the operation lever) is provided. The right and left operation levers 9 and 10 can be freely operated in the front-rear direction and the left-right direction. A pair of pilot valves 16 for generating a pilot pressure based on the left operating lever 1 are provided.
A pair of pilot valves 17 that generate a pilot pressure based on an operation of 0 in the front-rear direction and a pair of pilot valves 18 that generate a pilot pressure based on an operation of the left operating lever 10 in the left-right direction are provided. The hydraulic oil for pilot pressure is supplied from the pump 36 to the pilot valves 15 to 18, and the pilot pressure from the pilot valves 15 to 18 is supplied to the control valves 21 to 25.

When the right operation lever 9 is operated forward or backward with the above configuration, the control valve 21 of the boom 4 is operated to the down side or the up side, and when the right operation lever 9 is operated to the right or left, the control of the bucket 6 is performed. The valve 23 is operated to the soil discharge side or the scraping side. When the left operation lever 10 is operated forward or backward, the control valve 22 of the arm 5 is operated to the raising side or the scraping side, and when the left operation lever 10 is operated to the right or left, the control valve 24 of the swivel base 2 is swung to the right side. Or it is operated to the left of the turn. Operation pedal (not shown) provided on the swivel base 2
When the pedal is operated to the left or right, the control valve 25 is operated to the right swing side and the left swing side of the backhoe device 3 by the pilot pressure from the pilot valve (not shown) of the operation pedal.

In this case, since the pilot pressure increases or decreases depending on the operation amount from the neutral position of the right and left operation levers 9 and 10, the control valve increases as the operation amount from the neutral position of the right and left operation levers 9 and 10 increases. 21 to 24 are operated to the high flow rate side. That is, the larger the right and left operating levers 9 and 10 are operated, the faster the first to third hydraulic cylinders 11, 12, 13 and the hydraulic motor 14 operate.

In this backhoe, the pilot valves 15 to 1 described above are used for a remote control operation box 27 which will be described later.
Apart from 8, 5 electromagnetically operated auxiliary pilot valves 2
0, 26, 45, 46, 47 are provided. As shown in FIG. 2, a switching valve 32 is provided in the oil passage 19 from the pump 36, and the oil passage 41 from the switching valve 32 to the pilot valves 15 to 18 and the auxiliary pilot valves 20, 26, 45, 4 are provided.
The oil passage 42 to 6, 47 is provided, and the oil passage 42 has 5
The individual auxiliary pilot valves 20, 26, 45, 46, 47 are connected in parallel.

The switching valve 32 is an electromagnetically operated type, and the pump 3
Hydraulic oil for pilot pressure from 6 to 15
18 to the oil passage 41, and the auxiliary pilot valves 20, 2
6, 45, 46, 47 positions where the oil passage 42 is not supplied,
And the hydraulic oil for pilot pressure from the pump 36 is supplied to the oil passages 42 of the auxiliary pilot valves 20, 26, 45, 46 and 47, but not to the oil passages 41 of the pilot valves 15 to 18, at two positions. Alternate switching operation is possible. In the pair of oil passages 34, 51, 52, 53, 60 for hydraulic oil for pilot pressure to the control valves 21 to 25, the pair of oil passages 35 from the auxiliary pilot valves 20, 26, 45, 46, 47,
50, 54, 55 and 56 are connected via a shuttle valve 57.

In the normal excavation work state, the switching valve 32 supplies the hydraulic oil for pilot pressure from the pump 36 to the pilot valve 1.
Supply to the oil passage 41 of 5-18, auxiliary pilot valve 20,
The oil passages 26, 45, 46, 47 are operated at positions where they are not supplied. As a result, pilot pressure is generated based on the operation of the right and left operation levers 9 and 10 and the operation pedal, and the control valves 21 to 25 are operated. In this case, the upper limit of the pilot pressure is determined by the relief valve 58 of the oil passage 19, and the speed corresponding to the upper limit of the pilot pressure is the maximum operating speed of the backhoe device 3 and the swivel base 2.

The state shown in FIG. 1 is a state in which the operation box 27 (corresponding to the operation section) is connected to the main body side via a cable 38. As shown in FIGS. 3 and 4, the operation box 27 includes a right operation stick 28 that can be operated front, rear, left and right.
Further, a left operation stick 29, an operation switch 30 which can be operated left and right, and a changeover switch 40 for changing over the changeover valve 32 of FIG. 2 are provided.

When the right operation stick 28 is operated forward or backward, the auxiliary pilot valve 45 of the boom 4 is operated, and when the right operation stick 28 is operated right or left, the auxiliary pilot valve 47 of the bucket 6 is operated. When the left operation stick 29 is operated forward or backward, the auxiliary pilot valve 46 of the arm 5 is operated, and when the left operation stick 29 is operated right or left, the auxiliary pilot valve 20 of the swivel base 2 is operated. When the operation switch 30 is operated to the left or right, the auxiliary pilot valve 26 for swinging drive of the backhoe device 3 is operated.

With the above-described structure, in a remote excavation work state using the operation box 27, a worker (not shown) beside the bucket 6 holds the operation box 27 and operates the changeover switch 40 of the operation box 27. Operate on the remote control side. As a result, the switching valve 32 shown in FIG. 2 transfers the hydraulic oil for pilot pressure from the pump 36 to the auxiliary pilot valve 20,
The oil is supplied to the oil passages 26, 45, 46, 47, and is not switched to the oil passages 41 of the pilot valves 15 to 18 (the remote excavation work state).

Therefore, when the right operation stick 28 of the operation box 27 is operated forward or backward, the auxiliary pilot valve 4
By the pilot pressure from 5, the control valve 21 of the boom 4 is operated to the down side or the up side. Right operation stick 28
When is operated to the right or left, the control valve 23 of the bucket 6 is operated to the soil discharging side or the scraping side by the pilot pressure from the auxiliary pilot valve 47. When the left operation stick 29 is operated forward or backward, the control valve 22 of the arm 5 is operated to the raising side or the scraping side by the pilot pressure from the auxiliary pilot valve 46. When the left operation stick 29 is operated rightward or leftward, the control valve 24 of the swivel base 2 is operated rightward or leftward by the pilot pressure from the auxiliary pilot valve 20. When the operation switch 30 is operated to the left or right, the control valve 25 is operated to the right swing side and the left swing side of the backhoe device 3 by the pilot pressure from the auxiliary pilot valve 26.

By operating the backhoe device 3 and the swivel base 2 as described above, accurate excavation work can be performed. The right and left operation sticks 28 and 29 and the operation switch 30 are of a neutral return type, and the right and left operation sticks 2
8 and 29, when the operation switch 30 is released, these return to the neutral position and the auxiliary pilot valves 20, 26, 45, 4
6, 47 also return to the neutral position, the control valves 21 to 25 return to the neutral position, and the backhoe device 3 and the swivel base 2 stop.

Similar to the normal excavation work state described above, the pilot pressure of the auxiliary pilot valves 20, 45, 46, 47 is configured to increase or decrease depending on the operation amount from the neutral position of the right and left operation sticks 28, 29. Therefore, the larger the operation amount from the neutral position of the right and left operation sticks 28, 29 is, the more the control valves 21 to 24 are operated to the larger flow rate side. That is, the larger the right and left operation sticks 28, 29 are operated, the faster the first to third hydraulic cylinders 11, 12, 13 and the hydraulic motor 14 operate. In this case, the upper limit of the pilot pressure of the auxiliary pilot valves 20, 26, 45, 46, 47 is determined by the relief valve 58 of the oil passage 19,
Even in the remote excavation work state, the backhoe device 3 and the swivel base 2 can be operated at the same speed as in the normal excavation work state.

When the changeover switch 40 of the operation box 27 is operated to the normal operation side in the above remote excavation work state, the changeover valve 32 shown in FIG. 2 causes the changeover valve 32 shown in FIG. 18 to the oil passage 41, and the auxiliary pilot valves 20, 26, 45, 46, 4
The oil passage 42 of No. 7 is switched to a position not supplied (corresponding to the normal excavation work state side). Thus, by operating the right and left operation levers 9 and 10 and the operation pedal of the swivel base 2, the control valves 21 to 25 operate the backhoe device 3 and the swivel base 2 to perform normal excavation work.

By switching the unload valve 59, all the hydraulic oil from the pump 36 can be returned to the tank,
Since the pilot pressure is not generated at all, even if the right and left operation levers 9 and 10 and the right and left operation sticks 28 and 29 of the operation box 27 are operated, the backhoe device 3
And the swivel base 2 is not operated.

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 attached drawings.

[Brief description of the drawings]

FIG. 1 is an overall side view of a backhoe equipped with a remote control operation box.

FIG. 2 is a hydraulic circuit diagram showing a pilot valve for the right and left operating levers, an auxiliary pilot valve for the operating box, a switching valve for hydraulic oil for pilot pressure, a control valve, etc.

[Fig. 3] Front view of the entire operation box

FIG. 4 is an overall plan view of an operation box

[Explanation of symbols]

 2 swivel base 3 backhoe device 4 boom 5 arm 6 bucket 9, 10 operating lever 11 first hydraulic cylinder 12 second hydraulic cylinder 13 third hydraulic cylinder 14 hydraulic motor 15, 16, 17, 18 pilot valve 20, 45, 46, 47 Auxiliary pilot valve 21, 22, 23, 24 Control valve 27 Operation part 32 Switching valve 36 Pump

Claims (1)

(57) [Claims] 1. A hydraulic motor (14) for driving a swivel base (2) to swing, a first hydraulic cylinder (11) for swinging a boom (4) of a backhoe device (3) up and down, and a backhoe device (3). Hydraulic oil is supplied to each of the second hydraulic cylinder (12) that swings and drives the arm (5) and the third hydraulic cylinder (13) that swings and drives the bucket (6) of the backhoe device (3). Four pilot-operated control valves (21), (22), (23) on the machine side for supply / discharge operation
(24) and pilot valves (15), (16), (1) that generate pilot pressure based on the operating positions of operating levers (9), (10) provided in the control section of the swivel base (2).
7) and (18) are provided, and the pilot valve (15),
The pilot pressures from (16), (17) and (18) are supplied to the four control valves (21), (22), (23) and (2).
4), and the four control valves (2) by pilot pressure based on the operation of the operation levers (9), (10).
1), (22), (23), (24) is a backhoe configured to be operable, said four control valves (21), (22), (23), (2
4) An electromagnetically operated auxiliary pilot valve (20), (45), (46), (47) capable of supplying pilot pressure to 4),
This auxiliary pilot valve (20), (45), (46),
(47) is provided with an operating section (27) capable of being electrically and remotely operated, and hydraulic oil for pilot pressure from the pump (36) is supplied to the pilot valves (15), (16), (17) and (18). To
Supply the auxiliary pilot valves (20), (45),
Normal excavation work state not supplied to (46) and (47),
And hydraulic oil for pilot pressure from the pump (36)
The auxiliary pilot valves (20), (45), (4
6), (47), the pilot valve (15),
Remote drilling not supplied to (16), (17) and (18)
A switching valve (3
Backhoe equipped with 2) .