JPH0510044Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a piping structure for a hydraulic excavator, and in particular to a piping structure connecting a directional control valve and a pipe body connected to a cylinder that drives a front component. .

<Prior Art> FIGS. 5 and 6 are explanatory diagrams showing a conventional piping structure, with FIG. 5 being a plan view and FIG. 6 being a side view. In these figures, reference numeral 1 denotes a main body of a hydraulic excavator, which has a running body 3 running by a running motor 2 at the lower part, and a swinging body 5 rotating by a swing motor 4 at the upper part. 6 is a boom rotatably connected to the revolving body 5; 7 is an arm rotatably connected to the boom 6; 8 is a bucket rotatably connected to the arm 7; , arm 7, and bucket belt 8 constitute front components. 9 is a boom cylinder that drives the boom 6, 10 is an arm cylinder that drives the arm 7, 11 is a bucket cylinder that drives the bucket 8, and 12a and 12b are arm cylinders 10.
Pipe bodies 13a, 13b having rigidity connected to
is a rigid pipe connected to the bucket cylinder 11. In addition, in FIGS. 5 and 6, only the tube connected to the arm cylinder 10 and the tube connected to the bucket cylinder 11 are shown to simplify the explanation.

Reference numerals 14 and 15 indicate directional control valves that control the driving of the boom cylinder 9, arm cylinder 10, and bucket cylinder 11.The spools thereof are slidable in a horizontal plane, and have a supply port on the upper surface. The driver's cab 16 is located at the rear of the driver's cab 16 provided above the vehicle. 17a, 17b, 18a, and 18b are rigid pipe bodies connected to the supply ports of the directional control valves 14 and 15, respectively, and extend along the back of the driver's cab 16, and further along the side of the driver's cab 16. The end is bent along the rotation motor 4.
It is located nearby. 19a, 19
b are tube bodies 17a, 17b and tube body 12, respectively.
20a and 20b are flexible tubes, that is, hoses connecting the tubes 18a and 12b, respectively.
It is a flexible tube, that is, a hose, which connects the tubes 13a, 13b and the tubes 13a, 13b.

In the piping structure constructed in this way, the direction of flow of the pressure oil discharged from the hydraulic pump (not shown) is controlled by the direction switching valves 14 and 15, and for example, the pressure oil is transferred to the pipe body 17a, the hose 19a, etc. , is supplied to the boom cylinder 9 via the pipe body 12a, and the return oil is supplied to the pipe body 12b, the hose 19b, and the pipe body 17.
b, the arm 7 rotates, and, for example, the pressure oil is introduced into the pipe body 18a, the hose 20a, the pipe body 13
a, and the return oil is supplied to the bucket cylinder 11 through the pipe body 13b, the hose 20b, and the pipe body 18.
The bucket 8 is rotated by being guided through the pipe body b, and pressure oil is guided to the boom cylinder 9 through a pipe body (not shown), so that desired excavation work can be performed as the boom 6 rotates. can.

<Problems to be solved by the invention> By the way, in the piping structure configured in this way, the above-mentioned pipe bodies 12a, 12b, 13a, 1
3b, hoses 19a, 19b, 20a, 20b,
As illustrated in the pipe bodies 17a, 17b, 18a, and 18b, the inlet side for one actuator,
At least two pipe paths on the exit side are required, that is, at least 12 pipe paths are required corresponding to the boom cylinder 9, arm cylinder 10, bucket cylinder 11, swing motor 4, and two travel motors 2. Furthermore, if two circuits are combined, the number of pipe routes or pipes will further increase, leading to a complicated structure. Therefore, it is desired to reduce the number of these piping as much as possible without impairing the functions required of the original hydraulic excavator, but in the case of the conventional piping structure shown in Figs. 5 and 6 mentioned above, , the supply ports of the directional control valves 14, 15 and the hoses 19a, 19b, 20a, 20b are connected to rigid pipe bodies 17a, 17b, 18a, 18.
Since the configuration is such that the pipes are connected at b, the number of pipes is still large, and since the number of pipe connection parts is also large, there is a problem in that a large amount of oil leaks. Further, the directional control valves 14 and 15 are arranged at the back of the driver's cab 16, and the pipe bodies 17a, 17b, 1 connected to these directional control valves 14 and 15 as described above are arranged at the back of the driver's cab 16.
8a and 18b, the driver's cab 16
This occupies a space including the back of the motor 4 and the vicinity of the swing motor 4, and requires a large installation space.
Furthermore, as described above, the directional switching valves 14 and 15 have supply ports on the top surface, and the spools slide in a horizontal plane, so when replacing the spools, it is necessary to Valve 1
The spool must be attached and detached in an extremely narrow space near the sides of the spools 4 and 15, making this spool replacement work complicated.

The present invention was developed in view of the above-mentioned actual situation in the prior art, and its purpose is to reduce the number of pipes, require a small installation space, and facilitate the replacement of the directional valve spool. Our goal is to provide a piping structure for hydraulic excavators that can be used.

<Means for solving the problem> In order to achieve this objective, the present invention connects a pipe connected to a cylinder that drives a front component and a directional control valve that controls the driving of the cylinder. In the piping structure of a hydraulic excavator, the directional control valve consists of a spool arranged vertically and supply ports formed on both sides.
This directional switching valve is placed in the rear part of the foot of the boom, which is one of the front components, for example, at the rear of the swing motor, and the direction connecting both sides of the directional switching valve is along the width direction of the main body. The pipe body connected to the above-mentioned cylinder is connected by a flexible pipe body, that is, a hose.

<Function> As described above, the present invention has a structure in which the pipe body connected to the cylinder that drives the front component and the supply port of the directional control valve are connected by a flexible pipe body. , there is no need for a rigid pipe between the flexible pipe and the supply port of the directional valve, and therefore the number of piping can be reduced.

Furthermore, since the directional control valve is placed at the rear of the foot of the boom, the installation space is small, and the space at the back of the operator's cab can be used for installing other equipment.

In addition, the directional control valve is designed so that the spool can slide vertically, and the supply ports are provided on both sides, so the sufficiently large upper space of the directional control valve can be used for spool replacement work. Therefore, the replacement work can be easily performed.

<Example> Hereinafter, the piping structure of the hydraulic excavator of the present invention will be explained based on the drawings.

1 and 2 are explanatory diagrams showing one embodiment of the present invention, in which FIG. 1 is a plan view, FIG. 2 is a side view, and FIG. 3 is an enlarged detailed view of the main part corresponding to FIG. FIG. 4 is an enlarged detailed view of the main part corresponding to FIG. 2.

In these figures, 1 is the main body, 3 and 5 are the traveling and rotating bodies that make up the main body 1, 4 is the swing motor, 6, 7, and 8 are the boom, arm, and bucket, respectively, and 9, 10, and 11 are the booms. Cylinder, arm cylinder, bucket cylinder, 12a and 12b are rigid pipe bodies connected to the arm cylinder 10, 13a and 13b are rigid pipe bodies connected to the bucket cylinder 11, 16 is a driver's cab, These are equivalent to those shown in FIGS. 5 and 6 described above.

Reference numeral 21 denotes a directional switching valve for controlling the driving of the boom cylinder 9, arm cylinder 10, and bucket cylinder 11, and is arranged at the rear portion of the foot of the boom 6, for example, at the rear of the swing motor 4. The directional switching valve 21 has a spool that is vertically slidable, has supply ports on both sides of the spool, and is arranged so that the direction connecting both sides runs along the width direction of the main body 1. It has been done. 22a, 22b
is the pipe body 12 connected to the arm cylinder 10
a, 12b and a supply port located on one side of the directional control valve 21. It is a flexible tube, that is, a hose, that connects the supply port located on the other side of the directional control valve 21.

For piping structures configured in this way,
The hose 2 connects the supply ports provided on both sides of the directional control valve 21 and the pipe bodies 12a, 12b, 13a, 13b.
2a, 22b, 23a, 23b, and the supply port of the directional control valve 21 and the hose 22
a, 22b, 23a, and 23b are directly connected without requiring a rigid tube, the number of pipes can be reduced by the amount corresponding to the rigid tube.

Furthermore, since the directional control valve 21 is arranged at the rear of the swing motor 4 located at the rear part of the foot of the boom 6, the installation space is small, and therefore the space in the operator's cab 16 can be used for other equipment, etc. For example, it can be used as a work tool box installation space or a hydraulic oil tank installation space.

In addition, the directional control valve 21 has a spool that is slidable in the vertical direction, and supply ports are provided on both sides, so that a sufficient working space is formed on the upper surface of the directional control valve 21. Therefore, by removing the cap attached to the top surface of the directional control valve 21, the spool can be easily replaced, and the spool replacement work can be easily performed.

<Effects of the invention> Since the piping structure of the hydraulic excavator of this invention is configured as described above, the number of piping can be reduced compared to the conventional method, which has the effect of reducing manufacturing costs and the amount of oil leakage. At the same time, the installation space is small, the tool box, oil tank, etc. can be installed in the back space of the operator's cab, and the spool of the directional control valve can be easily replaced, reducing the number of man-hours required for this work. This has the effect of reducing maintenance costs.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams showing one embodiment of the piping structure of the hydraulic excavator of the present invention, in which FIG. 1 is a plan view, FIG. 2 is a side view, and FIG. 3 corresponds to FIG. 1. FIG. 4 is an enlarged detailed view of the main parts corresponding to FIG. 2, FIGS. 5 and 6 are explanatory diagrams showing the piping structure of a conventional hydraulic excavator, and FIG. 5 is a plan view. FIG. 6 is a side view. 4...Swivel motor, 6...Boom, 10...Arm cylinder, 11...Bucket cylinder, 12
a, 12b, 13a, 13b... tube body, 21...
Directional switching valve, 22a, 22b, 23a, 23b...
…hose.

Claims (1)

[Claims for Utility Model Registration] (1) In the piping structure of a hydraulic excavator that connects a pipe connected to a cylinder that drives a front component and a directional switching valve that controls the drive of the cylinder, the above-mentioned directional switching The valve consists of a spool arranged vertically and supply ports formed on both sides, and this directional valve is installed at the rear part of the foot of the boom, which is one of the front components, and furthermore, the both sides are formed. A piping structure for a hydraulic excavator, characterized in that the directional switching valve is arranged so that the connecting direction is along the width direction of the main body, and the directional switching valve and the pipe body connected to the cylinder are connected by a flexible pipe body. (2) The piping structure of a hydraulic excavator according to claim (1) of the utility model registration, characterized in that the directional switching valve is disposed at the rear of the swing motor located at the rear part of the foot of the boom.