JP2721082B2 - Hydraulic operation structure of backhoe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a hydraulic cylinder for a boom,
Each of a hydraulic cylinder for an arm, a hydraulic cylinder for a bucket, and a hydraulic cylinder for turning, a pilot-operated control valve group for supplying and discharging hydraulic oil, an operating lever for selecting the hydraulic actuator to be operated, and an operating lever. A pilot valve for outputting the result selected by the operation as a pilot pressure, and a spool type switching unit capable of transmitting the pilot pressure from the pilot valve to any of the control valves and changing the transmission target control valve The present invention relates to a backhoe hydraulic operation structure provided with a backhoe.

[0002]

2. Description of the Related Art In such a configuration,
It has the feature that the linkage between the pilot valve and the transmission target control valve that differs for each manufacturer can be easily changed and operated by the spool type switching unit. As a hydraulic operation structure of this type of backhoe, as shown in Japanese Patent Publication No. 1-60702, piping means such as a hydraulic hose is provided to connect a pilot valve and a spool type switching unit.

[0003]

However, in this case, it is necessary to secure an installation space for the piping means, and it is difficult to secure an installation space in consideration of interaction with other equipment. Therefore, the design and manufacturing restrictions are large.

An object of the present invention is to provide a simple mechanism as a means for connecting a pilot valve and a spool type switching unit, thereby ensuring a compact structure and reducing restrictions on the arrangement space. is there.

[0005]

A feature of the present invention is that the pilot valve group is directly connected via a first seal plate to the surface of an oil passage plate having a plurality of oil grooves formed in the front and back surfaces. At the same time, the spool type switching unit is directly mounted on the back surface of the oil passage plate via the second seal plate, and the operation and effect are as follows.

[0006]

(A) By providing an oil passage plate having a plurality of oil grooves, this oil passage plate can be used instead of a hydraulic pipe, and the oil passage plate itself only forms a plurality of oil passages. Therefore, the structure itself can be made compact, the arrangement space can be reduced as compared with general pipes and hoses for piping, and the oil passage plate thus configured is combined with a pilot valve group. With the spool type switching unit,
By directly connecting the components, it is possible to make the configuration compact as a whole, and it is easy to find an arrangement space accordingly. (B) In addition, since the oil groove is merely formed in the oil passage plate in a recessed state on the front and back surfaces, the hydraulic oil sent from the pilot valve enters the oil groove on the front surface and is flat at the end thereof. And enters the starting end of the oil groove on the back side almost without moving in the thickness direction of the oil passage plate from the end thereof, reaches the end and enters the spool type switching unit, so that the thickness of the oil passage plate is thin. You can make something
The laminated structure of the pilot valve group and the spool type switching unit can be made thin and compact.

[0007]

According to the present invention, the thickness of the oil passage plate itself can be reduced by adopting the oil passage plate and forming the oil passage of the oil passage plate in the recessed oil groove. It is possible to have a configuration that does not.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 6, the swivel base 2 is supported above the crawler traveling device 1, and a backhoe device 3 is provided at the front of the swivel base 2.
And a dozer 20 to constitute a backhoe working vehicle. The backhoe device 3 includes a hydraulic cylinder 1 for a boom.
1. A boom 4 swingably driven up and down by 1, a four-link intermediate member 53 that can be horizontally folded by an offset hydraulic cylinder 7, an arm 5 and a bucket hydraulic cylinder driven to swing back and forth by an arm hydraulic cylinder 12. The bucket 6 has a bucket 6 and the like, which are driven to be swung and swung by the thirteen. or,
A turning hydraulic motor 14 for driving the turntable 2 for turning, and a dozer elevating cylinder 30 for driving the dozer 20.
It has.

Next, three hydraulic cylinders 11, 12, and 13 for a boom, an arm, and a bucket, and a turning hydraulic motor 1
4. Offset cylinder 7 and lifting cylinder 3 for dozer
The hydraulic circuit for 0 will be described. As shown in FIG. 4, a hydraulic oil from a variable displacement type first pump 9 driven by an engine 8 is supplied to a left traveling control motor 2 for a left traveling hydraulic motor 10 for a left crawler traveling device 1.
6, the control valve 22 for the arm for the hydraulic cylinder 12 for the arm, the control valve 27 for the service port 16, and the control valve 15 for the confluence for the boom 4.

As shown in FIG. 4, hydraulic oil from a variable displacement type second pump 17 driven by the engine 8 is supplied to a right traveling hydraulic motor 18 for the right crawler traveling device.
Right control valve 28, boom hydraulic cylinder 1
1 and the bucket control valve 23 for the bucket hydraulic cylinder 13. Hydraulic oil from a third pump 19 driven by the engine 8 is supplied to a turning control valve 24 for the turning hydraulic motor 14,
Offset control valve 2 for offset cylinder 7
5. Supply to the dozer control valve 29 for the lifting cylinder 30 for the dozer 20.

Each of the control valves 15, 21, 22, 23, 24 is of a neutral return type and of a pilot operation type. Next, the operation structure of the control valves 15, 21, 22, 23, 24 will be described. As shown in FIGS. 3 and 4, a pair of right and left work operation levers RL and LL for selecting a hydraulic actuator to be operated is provided on the front side of the control section of the swivel 2. This right and left work operation lever R
L, LL are operable back and forth and right and left. The first to fourth pilot valves 31, 32, 33, and 34 that are switched based on each operation to generate a pilot pressure are integrally incorporated in the right valve unit 51, and the right and left pilot valves 31, 32, 33, and 34 are integrated into the right valve unit 51. The right operation lever RL is attached to the valve unit 51, and the fifth to eighth pilot valves 35, 3
6, 37, and 38 are integrated into the left valve unit 50, and the left operation lever LL is attached to the left valve unit 50. Further, the hydraulic oil from the fourth pump 47 driven by the engine 8 is supplied to the first to fourth pumps via the unload valve 54.
8 pilot valves 31-38. The following connection form is adopted for the left valve unit 50 and the right valve unit 51 described above. That is, as shown in FIGS. 1 and 2, the first seal plate 4
5 and a spool type switching unit 39 is mounted on the back surface (lower surface) of the oil passage plate 42 via a second seal plate 46, and the fifth to eighth pilot valves 35 to 38 are mounted. Is controlled in the spool type switching unit 39 so that the pilot pressure from the control valve 22 is supplied to the control valves 22 and 24 via the spool type switching unit 39 so as to act on the transmission target control valve in the control valves 22 and 24. Let it. On the other hand, the right valve unit 51
A pipe hose 43 is directly attached to the control valve 1 to control the pilot pressure from the first to fourth pilot valves 31 to 34.
5, 21 and 23.

The structure of the oil passage plate 42 will be described. As shown in FIG. 2, the surface 42A of the oil passage plate 42
In addition, a plurality of oil grooves 42a having a starting end corresponding to the output port of the left unit valve 50 are formed in a concave shape,
On the back surface 42B of the oil passage plate 42, a plurality of oil grooves 42b having a starting end corresponding to the end of the oil groove 42a on the front surface are formed in a concave shape.

Next, the spool type switching unit 39 will be described. As shown in FIGS. 1 to 3, the spool type switching unit 39 includes a flat block body 40 as a unit main body and a spool 41 formed in a slide operation type.
And four first to fourth input ports A, B, C, and D are formed on the upper surface of the flat block body 40, and four output ports a, b, c, and d are formed on the bottom surface. ,
An oil passage plate 42 described later is directly attached to the upper surface, and piping hoses 43 are attached to output ports on the bottom surface, respectively. In the figure, reference numeral 44 denotes a swing operation lever for the spool type switching unit 39.

Next, connection of the spool type switching unit 39 to the pilot valve and the control valve will be described. As shown in FIG. 3, when the left operating lever LL is swung left, right, front, and rear, respectively, the fifth, sixth, seventh, and eighth pilot valves 35 to 38 are operated, and the first and second pilot valves 35 to 38 are respectively operated. The pilot pressure is sent to the input port A, the second input port B, the third input port C, and the fourth input port D. On the other hand, each output port is connected to the merging control valve 15, the boom control valve 21, the arm control valve 22, the bucket control valve 23, and the turning control valve 24 as follows. The first output port a connects to the turning left position of the turning control valve 24, the second output port b connects to the turning right position of the turning control valve 24, and the third output port c.
Is connected to the position above the arm of the arm control valve 22,
The fourth output port d is connected to the arm scraping position of the arm control valve 22. Therefore, as shown by X in FIG. 5, the operation direction of the operation lever LL corresponds to the work content.
Next, when the spool type switching unit 39 is pushed in with the operation lever 44, the first input port A is connected to the third output port c, the second input port B is connected to the fourth output port d, and the third input port C is connected. Is connected to the second output port b, and the fourth input port D is connected to the first output port a. Therefore, as shown by Y in FIG. 5, the operation direction of the operation lever LL corresponds to the work content. Next, the right operation lever RL is
When the swing operation is performed on the left, right, front, and rear, respectively, the first, second, third, and fourth pilot valves 31 to 34 are operated, and the first pilot valve 31 is moved to the bucket scraping position of the bucket control valve 23. The second pilot valve 32 is connected to the bucket discharging position of the bucket control valve 23, and the third pilot valve 32 is connected to the third pilot valve 32.
The pilot valve 33 is connected to the boom lower position of the boom control valve 21, and the fourth pilot valve 34 is connected to the merging control valve 15 and the boom upper position of the boom control valve 21. Therefore, as shown by X and Y in FIG. 5, the operation direction of the operation lever RL corresponds to the work content.

The traveling operation structure will be described. As shown in FIG. 4, traveling operation levers 48 and 49 are provided for the left and right traveling control valves 26 and 28, respectively, and the traveling operation levers 48 and 49 are attached to the upper surface of the oil passage plate 42 as shown in FIG. Is attached via a bracket. The traveling operation levers 48 and 49 and the spools of the left and right traveling control valves 26 and 28 are linked via a link linking mechanism 52.

Alternative Embodiment Although only the left valve unit 50 is attached to the oil passage plate 42, the right valve unit 51 may be attached at the same time. The cross-sectional shape of the oil grooves 42a and 42b formed in the oil passage plate 42 may be any of a circular diameter, an ellipse, a polygon, and the like as long as a part thereof is in an open state. The unload valve 54 may be directly attached to the back surface of the oil passage plate 42.

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 a perspective view showing an assembled state of an oil passage plate, a spool type switching unit, and an operation system.

FIG. 2 is a plan view showing an oil passage plate and a seal plate.

FIG. 3 is a hydraulic circuit diagram for connecting a pilot valve and a spool type switching unit.

FIG. 4 is a hydraulic circuit diagram of the backhoe device.

FIG. 5 is a table showing operation states of a left and right operation lever and a backhoe device.

FIG. 6 is a side view of the backhoe.

[Explanation of symbols]

 11 Boom Hydraulic Cylinder 12 Arm Hydraulic Cylinder 13 Bucket Hydraulic Cylinder 14 Rotating Hydraulic Motor 21-24 Control Valve 31-38 Pilot Valve 39 Spool Type Switching Unit 42 Oilway Plate 42A Surface 42B Backside 42a, 42b Oil Groove 45th 1 seal plate 46 second seal plate LL left operating lever RL right operating lever

Claims (1)

(57) [Claims] 1. A hydraulic cylinder for a boom (11), a hydraulic cylinder for an arm (12), and a hydraulic cylinder for a bucket (1).
3) A pilot-operated control valve (21, 22, 2) for supplying and discharging hydraulic oil to each of the turning hydraulic motors (14).
3, 24) group, an operating lever (RL, LL) for selecting the hydraulic actuator to be actuated, and a pilot valve (31) for outputting a result selected by operating the operating lever (RL, LL) as a pilot pressure. , 32,33,34,35,
36, 37, 38) and the pilot valve (31, 32, 33, 34, 35, 3)
6, 37, 38) to any of the control valves (21, 22, 23, 24),
A hydraulic operation structure of a backhoe provided with a spool type switching unit (39) capable of changing a transmission target control valve, wherein a plurality of oil grooves (42) are provided on front and rear surfaces (42A) and (42B).
a) An oil passage plate (42) in which (42b) is recessed.
A first seal plate (45) on its surface (42A).
Through the pilot valve (31, 32, 33, 3)
4) A hydraulic operation structure of a backhoe in which the spool type switching unit (39) is directly mounted on the back surface (42B) of the oil passage plate via a second seal plate (46), while the group is directly mounted.