JPH1181363A - Vertical shaft excavator and clamshell operation hydraulic circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a fear of bend breakage occurring to a work arm, to reduce a fear of irregular winding occurring to a vertical shaft excavator using a standard work arm and the hydraulic hose of a clamshell operation hydraulic circuit, and to reduce a cost. SOLUTION: Since, by suspending a multistage telescoping cylinder 6 of a work arm 5 from the tip of the work arm 5 and coupling a clamshell 8 to the lower end thereof through a swivel joint 7, a bending force is not exerted on a multistage telescopic cylinder 6, and a fear of bend breakage occurring to the work arm 5 of standard specification is reduced. Further, by locating a pilot type check valve releasable of a check function by a pilot pressure, an excessive pressure generated at a clamshell opening closing cylinder 9 by an excavation reaction force is not transmitted to a portion between the pilot check valve of an oil pressure hose and a hose reel 12, whereby a low pressure oil pressure hose is usable. Since abnormal expansion does not occur, the wound part of the oil pressure hose wound around a hose reel 12 is prevented from protrusion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the technical field of a pit excavator for excavating a deep pit in the ground at the time of deep foundation work and a clamshell operating hydraulic circuit of the pit excavator.

[0002]

2. Description of the Related Art For deep foundation work, a deep pit is excavated in the ground, and a pit excavator is used for excavation of the pit. As such a pit excavator, one having a configuration as shown in FIGS. 4 and 5, for example, is known. Hereinafter, the configuration of the pit excavator shown in FIG. 4 (conventional example 1) and FIG. 5 (conventional example 2) will be described.

First, referring to FIG. 4 of the perspective view,
A schematic configuration of a pit excavator according to Conventional Example 1 will be described. That is, this pit excavator is a crawler-type traveling carriage 5 that can travel freely.
1. An earthworking machine body 50 having a revolving body 52 rotatably mounted on a traveling vehicle 51, a work arm 53 called a boom supported on the revolving body 52 so as to be able to undulate, and an earthworking machine. A multi-stage telescopic arm (in this example, a three-stage telescopic type) 54 rotatably supported at the tip of the working arm 53 of the machine main body 50, and a known multi-stage telescopic arm 54 connected to the tip of the multi-stage telescopic arm 54 And a clamshell 55. In the case of a pit excavator having such a configuration, the multi-stage telescopic arm 54 is extended according to the depth of the pit to be excavated.

Next, with reference to FIG.
Explaining the schematic configuration of the pit excavator according to Conventional Example 2, the pit excavator includes a crawler-type traveling trolley 61 that can travel freely, a revolving body 62 that is pivotably supported on the traveling trolley 61, An earth-moving machine main body 60 provided with a working arm 63 supported on a revolving body 62 so as to be able to undulate and bend freely, and a plurality of cylindrical bodies 64a vertically connected to a tip of the working arm 63 of the earth-moving machine main body 60 and connected thereto. Clamshell connecting cylinder 64
And a clamshell 65 connected to the tip of the clamshell connection cylinder 64. In the case of a pit excavator having such a configuration, a working arm 63 and a clamshell connecting cylinder 64 having a length corresponding to the depth of the pit to be excavated are provided.
Are used.

On the other hand, a hydraulic fluid circuit for operating a clamshell operating hydraulic circuit supplies hydraulic oil to a clamshell opening / closing cylinder (not shown) for opening and closing the clamshell from the earthworking machine main body, and returns hydraulic oil from the clamshell opening / closing cylinder to the earthworking machine main body. The hydraulic hoses are configured as follows. First, in the case of the pit excavator according to Conventional Example 1, for example, a hydraulic hose is wound around a hose reel, and the hydraulic hose is fed from the hose reel in accordance with the extension length of the multi-stage telescopic arm 54, and the hose is It is designed to be wound on a reel.

Next, in the case of the vertical excavator according to the second conventional example, the vertical excavator is provided along each of the cylinders 64a constituting the clamshell coupling cylinder 64, and is used to make the clamshell coupling cylinder 64 longer. Each time the cylindrical body 64a is connected to each other, each of the hydraulic hoses provided along the cylindrical body 64a is sequentially connected by, for example, a quick coupler connected to a hose end.

[0007]

SUMMARY OF THE INVENTION Conventional Example 1 or 2
According to the pit excavator according to the above, a deep pit can be excavated in the ground at the time of the deep foundation work, and thus it is considered to be useful as such. However, these conventional examples 1
Or, the pit excavator according to 2 has problems to be solved as described below.

First, in the vertical excavator according to the conventional example 1, as described above, the clam shell is vertically provided at the tip of the multi-stage telescopic arm. A bending force acts on the multi-stage telescopic arm due to the reaction force, and the multi-stage telescopic arm and a working arm (boom) rotatably supporting the multi-stage telescopic arm may be damaged. In addition, the hydraulic hose of the clamshell operating hydraulic circuit expands due to excessive pressure generated in the clamshell opening / closing cylinder during excavation work, and its diameter increases, and the portion wound around the hose reel protrudes, causing turbulent winding. In addition to the above, there is a problem to be solved in that the use of a higher pressure hydraulic hose inevitably increases the manufacturing cost of the clamshell operating hydraulic circuit.

Next, in the pit excavator according to Conventional Example 2, since the clamshell connecting tube is always vertical, no bending force acts on the clamshell connecting tube, as in the pit excavator according to Conventional Example 1. There is no fear that the multi-stage telescopic arm or the working arm is bent. However, as the vertical hole becomes deeper, it is necessary to increase the number of cylinders to be connected and lengthen the clamshell connection cylinder, so that the operation of connecting the cylinder and the hydraulic hose is difficult. In addition, since the standard work arm of the earthmoving machine cannot be used, it is necessary to separately prepare a special long work arm, and there is a problem to be solved that the cost of the pit excavator increases. Further, as for the hydraulic hose of the clamshell operating hydraulic circuit, there is a possibility that the hydraulic hose may burst due to excessive pressure generated in the clamshell opening / closing cylinder during excavation work. Therefore, a higher-pressure hydraulic hose must be used.

Accordingly, an object of the present invention is to reduce the risk of bending of the working arm and the risk of turbulence of the hydraulic hose, to reduce the cost of the clamshell operating hydraulic circuit, and to reduce the cost of the standard working arm. It is an object of the present invention to provide a pit excavator and a clamshell operating hydraulic circuit of the pit excavator that can be used.

[0011]

Therefore, in order to solve the above-mentioned problems, a feature of the means adopted by the pit excavator according to claim 1 of the present invention is that the earth-moving machine body which can move freely, and The multi-stage telescopic cylinder is provided at the tip of the working arm of the earth-moving machine main body and a clam shell connected to a lower end of the multi-stage telescopic tube.

A feature of the means adopted by the clamshell operating hydraulic circuit of the pit excavator according to the second aspect of the present invention is that a multistage telescopic device is provided at the tip of the working arm of the main body of the earthmoving machine which can move freely. Hydraulic oil is supplied from the earthworking machine main body to a clamshell opening / closing cylinder that is disposed along the cylinder and opens and closes a clamshell connected to the lower end of the multistage telescopic cylinder, and supplies hydraulic oil from the clamshell opening / closing cylinder. In the clamshell operating hydraulic circuit of the pit excavator provided with a pair of hydraulic hoses returned to the earthworking machine main body side, the hydraulic oil for releasing the non-return function from the other side to the clamshell opening / closing cylinder side of each of the pair of hydraulic hoses. A pilot-type check valve that directs hydraulic oil from the main body of the earthmoving machine to the clamshell opening / closing cylinder is interposed. That.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a pit excavator and a clamshell operating hydraulic circuit of the pit excavator according to an embodiment of the present invention, showing a state in which a multistage telescopic cylinder is extended. 1, FIG. 2 showing a cross-sectional configuration of a multi-stage telescopic cylinder of a pit excavator, and FIG. 3 showing a hydraulic diagram of a clamshell operation hydraulic circuit.
This will be described with reference to FIG. 3A and FIG. 3B which is an enlarged view of a portion B in FIG.

Reference numeral 1 shown in FIG. 1 denotes a movable earth moving machine body. The earthmoving machine main body 1 is mounted on a crawler traveling traveling vehicle 2 and on the traveling vehicle 2 so as to be pivotable.
A revolving structure 3 having a cab 4, a boom 5 a supported by the revolving structure 3 so as to be able to move up and down, and the boom 5 a
And a bendable work arm 5 composed of an arm 5b rotatably supported at the tip of the work arm. In other words, the configuration of the earthmoving machine main body 1 is the same as that of a well-known hydraulic excavator main body, as is well understood from the above description.

At the end of the arm 5b of the working arm 5, a multi-stage telescopic cylinder 6 is vertically suspended via a universal joint 5c. The multi-stage telescopic cylinder 6 is of a three-stage telescopic type, and is vertically installed at the tip of an arm 5b via a universal joint 5c, and has a base end cylinder 6a in which a hose reel 12 is provided on the universal joint 5c; An intermediate cylinder 6b which is inserted into and removed from the base cylinder 6a,
The distal end cylinder 6 is inserted and inserted into and out of the intermediate cylinder 6b.
c. Then, a swivel joint 7 is attached to the tip of the tip cylinder 6c of the multi-stage telescopic cylinder 6,
A clamshell 8 having a well-known configuration that is opened and closed by the expansion and contraction operation of the rods of the clamshell opening and closing cylinders 9 and 9 is connected.

As shown in FIG. 2, the telescopic operation of the multi-stage telescopic cylinder 6 is performed by the telescopic operation of the rod of the telescopic cylinder 6d and the sprockets 6e, 6e provided at the upper and lower ends of the intermediate cylinder 6b. And a well-known configuration, which is performed by an integrated operation with a chain 6f fixed to the inner lower end of the base cylinder 6a and the outer upper side of the tip cylinder 6c. It is. Of course, there is also a configuration in which a sheave is used in place of a sprocket and a wire rope is used in place of a chain. Therefore, the present invention is not particularly limited to the expansion and contraction mechanism itself.

Therefore, the pit excavator 1 according to this embodiment
According to this, a multi-stage telescopic cylinder 6 supporting a clam shell 8 is vertically provided at the tip of an arm 5b, and the outer cylinder is connected to the multi-stage telescopic arm by the excavation reaction force of the clam shell as in the vertical excavator according to Conventional Example 1. Since the bending force does not act on the multi-stage telescopic cylinder 6, the risk that the multi-stage telescopic tube 6 and the working arm 5 are bent is reduced.

Further, even if the pit becomes deep due to the continuation of the excavation work, the hydraulic oil is supplied to the telescopic cylinder so that the multi-stage telescopic cylinder 6
Can be extended, so that the connecting operation of the cylinder and the hydraulic hose as in the pit excavator according to the conventional example 2 becomes unnecessary, and like the pit excavator according to the conventional example 1, This eliminates the need for labor required for the previous work, and eliminates the need to use a separately prepared long work arm, and the work arm 5 of the standard specification is sufficient. Furthermore, since it is possible to use a normal hydraulic excavator only by replacing the multi-stage telescopic cylinder 6 with a bucket, it is possible to easily change the application as compared with the vertical excavator according to the conventional example 1 or 2. There is also an effect.

Next, the structure of the clamshell operating hydraulic circuit 10 for opening and closing the clamshell 8 will be described with reference to FIGS. 3 (a) and 3 (b).
Reference numeral 11 denotes a hydraulic oil supply base pipe that communicates with a hose reel 12 from a hydraulic pressure source mounted on the earthmoving machine main body, and these hydraulic oil supply base pipes 11 and 11 are arranged along a working arm including a boom and an arm. Has been established. In addition, while communicating with these hydraulic oil supply base pipes 11 and 11,
The hydraulic hoses 13 and 14 (disposed inside the multi-stage telescopic cylinder) wound and fed out by the clamshell 8 are provided.
Hydraulic oil is supplied to the clamshell opening / closing cylinders 9, 9 for opening and closing, and is connected to a swivel joint 7 from which the hydraulic oil is returned from the clamshell opening / closing cylinders 9, 9.
On the swivel joint 7 side of these hydraulic hoses 13 and 14, a pilot check valve 15 having a configuration described later is interposed.

The direction in which the pilot check valve 15 is interposed is, as is well understood from FIG. 3B, the direction in which hydraulic oil flows from the hydraulic hoses 13 and 14 to the swivel joint 7 side ( Clamshell open / close cylinder 9, 9
From the direction in which the flow of the hydraulic oil in the direction of the earthworking machine body is blocked. A pilot passage 14a for releasing the check function of the first check valve 15a from the hydraulic hose 14 communicates with the first check valve 15a interposed in the hydraulic hose 13, and the hydraulic hose 14 The second check valve 15b interposed between the hydraulic hose 13 and the second check valve 15b
A pilot passage 13a for releasing the check function of the check valve 15b communicates. Although the pilot check valve 15 is integrally formed, the first check valve 15
a and the second check valve 15b may be divided.

Therefore, for example, when hydraulic oil is supplied to the clamshell opening / closing cylinders 9, 9 through the hydraulic hose 13, it is necessary to return the hydraulic oil discharged from the clamshell opening / closing cylinders 9, 9 through the hydraulic hose 14. At this time, the check function of the second check valve 15b is released by the pilot pressure supplied from the hydraulic hose 13 to the second check valve 15b through the pilot passage 13a. The discharged hydraulic oil is returned to the earthmoving machine main body through the hydraulic hose 14.

Conversely, when hydraulic oil is supplied to the clamshell opening / closing cylinders 9 via the hydraulic hose 14, the hydraulic pressure is supplied to the first check valve 15a from the hydraulic hose 14 through the pilot passage 14a. 1
The check function of the check valve 15a is released.

Therefore, the clam shell 8 can be opened and closed without any trouble. However, if excessive pressure is generated in the clam shell opening / closing cylinders 9 by excavation reaction force during excavation work, the first check valve 15 , 2 check valve 15a, 1
5b are both closed, and excessive pressure generated due to the excavation reaction acts on the portions of the hydraulic hoses 13, 14 from the pilot check valve 15 to the hose reel 12 and the hydraulic oil supply base lines 11, 11. You won't have to.

As described above, excessive pressure based on the excavation reaction force does not act on portions of the hydraulic hoses 13 and 14 from the pilot check valve 15 to the hose reel 12, and the hydraulic hoses 13 and 14 expand abnormally. Disappears. Therefore, the portions of the hydraulic hoses 13 and 14 that are wound around the hose reel 12 do not protrude, so that the risk of turbulence is reduced. In addition, there is no need to use a higher-pressure hydraulic hose that can withstand excessive pressure that greatly exceeds the normal working pressure, and it is sufficient to use a hydraulic hose that can withstand the normal working pressure. The cost of the hydraulic circuit 10 can be reduced.

In the above, the case where the main body of the earth-moving machine is of the crawler traveling type has been described as an example. However, the present invention can be applied to, for example, the main body of the earth-moving machine of the tire traveling type. The technical scope of the present invention is not limited. Also, the case where the multi-stage telescopic cylinder is a three-stage telescopic type has been described as an example, but the technical idea according to the present invention can be applied to a two-stage, four-stage or more multi-stage telescopic tube. The number of stages is not limited. Further, the case where the clamshell is opened and closed by two clamshell opening and closing cylinders has been described as an example.
The number is not limited to the number of clamshell opening / closing cylinders because there may be more than one.

[0026]

As described above, according to the pit excavator according to the present invention, the multi-stage telescopic cylinder supporting the clam shell is vertically provided at the tip of the working arm. As described above, the bending force does not act on the multi-stage telescopic tube due to the excavation reaction force of the clam shell, and there is no fear that the multi-stage telescopic tube or the working arm is bent. Also, even if the pit becomes deep, it is sufficient to supply hydraulic oil to the telescopic cylinder to extend the multi-stage telescopic cylinder,
Unlike the pit excavator according to Conventional Example 2, the connection of the cylinder and the connection of the hydraulic hose are not required, and there is no need to use a long special-purpose working arm. it can.

Further, according to the clamshell operating hydraulic circuit of the vertical excavator according to the present invention, when excessive pressure is generated in the clamshell opening / closing cylinder due to excavation reaction force during excavation work, the pilot check valve 15 is closed. The part from the pilot check valve to the hose reel of the hydraulic hose does not swell abnormally, reducing the risk of turbulence and using a higher-pressure hydraulic hose that can withstand excessive pressure. Therefore, it is only necessary to employ a hydraulic hose that can withstand normal working pressure, so that the cost of the clamshell operating hydraulic circuit can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view of a vertical excavator according to an embodiment of the present invention, showing a state in which a multistage telescopic tube is extended.

FIG. 2 is a cross-sectional configuration explanatory view of a multi-stage telescopic cylinder of the pit excavator according to the embodiment of the present invention.

3 (a) is an explanatory diagram of a clamshell operation hydraulic circuit, and FIG. 3 (b) is a diagram of FIG. 3 according to the embodiment of the present invention.
It is a B section enlarged view of (a).

FIG. 4 is a perspective view of a pit excavator according to Conventional Example 1.

FIG. 5 is a perspective view of a pit excavator according to Conventional Example 1.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Earth-moving machine main body, 2 ... Traveling trolley, 3 ... Revolving body, 5 ... Working arm, 5a ... Boom, 5b ... Arm, 5c ... Universal joint 6 ... Multi-stage telescopic cylinder, 6a ... Base end cylinder, 6b ... Intermediate cylinder Body, 6
c: tip cylinder, 6d: telescopic cylinder, 6e: sprocket, 6f: chain, 7: swivel joint, 8:
Clamshell, 9 Clamshell opening / closing cylinder 10 Clamshell operating hydraulic circuit, 11 Hydraulic oil supply base line, 12 Hose reel, 13 Hydraulic hose, 13a
... Pilot passage, 14 ... Hydraulic hose, 14a ... Pilot passage, 15 ... Pilot check valve, 15a ... First check valve, 15b ... Second check valve

Claims (2)

[Claims] 1. A movable earthmoving machine main body, a multi-stage telescopic cylinder vertically provided at a tip of a working arm of the earthmoving machine main body,
A pit excavator comprising a clam shell connected to a lower end of the multistage telescopic cylinder. 2. A clamshell disposed along a multi-stage telescopic tube vertically suspended from a tip of a working arm of a movable earthmoving machine main body to open and close a clam shell connected to a lower end of the multi-stage telescopic tube. In the clamshell operating hydraulic circuit of the pit excavator provided with a pair of hydraulic hoses, which supply hydraulic oil to the opening / closing cylinder from the earthworking machine main body side and return hydraulic oil from the clamshell opening / closing cylinder to the earthworking machine main body side, A pilot passage for guiding hydraulic oil for releasing the check function from the other side is connected to the clamshell opening / closing cylinder side of each hydraulic hose, and a pilot type reverse direction in which hydraulic oil is passed from the earthworking machine body side to the clamshell opening / closing cylinder. A clamshell operating hydraulic circuit for a pit excavator, wherein a stop valve is interposed.