JPS5910236Y2 - excavator - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an excavator suitable for excavating a shaft for a cast-in-place pile or the like, particularly a large-diameter (usually 1000 mm or more) shaft.

Conventionally, hammer grabs, reverse circulation drills, earth drills, etc. are known as large-diameter drilling machines, but hammer grabs generate impact noise and are restricted in their use locations, and reverse circulation drills are designed to be used due to the diameter of the drill pipe. It is impossible to excavate large gravel stones, and since Earthdonol rotates the rectangular shaft using a drive device fixed to the base machine, the weight of the packet at the lower end of the rectangular shaft alone cannot provide sufficient excavation surface pressure, so the shaft cannot be pushed. It had the disadvantage of requiring a lowering device.

On the other hand, the earth auger has a structure in which a screw is connected to a drive unit that is slidably attached to the leader mast, and the screws are added one after another to perform continuous excavation. When used for large-diameter excavation, there is a drawback that when a large-diameter screw is added to increase the length, the excavation rotational reaction force increases, and this increased excavation reaction force acts on the leader mast, making it difficult to perform large-diameter excavation. Ta.

The purpose of this project is to obtain an excavator that uses a screw to have strong excavation capacity similar to that of an earth auger, can obtain sufficient excavation surface pressure, and does not increase excavation reaction force. Embodiments thereof will be described below with reference to the drawings.

In FIG. 1, a leader mast 2 is supported in an upright state on the front end of a base machine 1, and the leader mast 2 has guide rails 3, 3 extending the entire length of the mast on the front thereof, and a top sheave block 4 is fixed to the upper end. A driving unit 7 consisting of a waterproof motor 5 and a speed reducer 6 connected therebelow is suspended by wires 9, 9 hanging from the toffee lock 4 so as to be able to move up and down.

The wires 9, 9 are connected to the sheave 8 attached to the upper end of the motor 5.
, 8 and pivoted within the top sheave block 4. Sheaves 10, 10, 11 . 11 and a winch (not shown) of the base machine 1 through sheaves 12, 12 on the rear surface of the mast.

An auger screw 14 is connected to the output shaft at the lower end of the reducer 6 in the drive section 7 via a mudguard guide plate 13, and a support shaft 2 of an appropriate length is connected to the center of the upper end of the motor 5.
One end of 1 is fixed.

In this case, the driving part 7, the screw 14 and the shaft 21 are in a straight line with each other, and the driving part 7 and the shaft 21 are made smaller in diameter than the screw 14.

The shaft guide block 15 located above the drive section 7 is attached to the guide rails 3, 3 of the mast with the slide metal fittings 26.
26 and the wire 16.1
6, it is supported so as to be able to rise and fall freely.

The wires 16, 16 are connected to the winch of the base machine 1 via sheaves 17, 17, 18, 18 which are shafted in the sheave lock 4 and the sheaves 12, 12 on the rear surface of the mast 2.

The shaft guide block 15 is provided with a guide hole 19, into which the support shaft 21 is slidably but non-rotatably inserted and supported, thereby transferring rotational reaction force during excavation by the screw 14 to the support shaft 21 and the support shaft 21. The shaft is arranged to be received by the mast 2 via the shaft guide block 15.

As a slidable but non-rotatable support structure for the support shaft 21, in this example, the support shaft 21 is a square shaft with a square cross section as shown in the fourth figure, and the shaft guide block 1
The guide hole 19 of No. 5 is shaped into a square hole that is appropriately larger than the support shaft 21, and rollers 20 are rotatably attached to the four inner surfaces of the square guide hole 19. A square shaft support shaft 21 is inserted into the shaft 19.

As another example, a structure is adopted in which a protrusion in the generatrix direction is provided on the outer surface of the round support shaft 21, and a groove is provided on the inner surface of the circular guide hole 19, and the protrusion is engaged with the groove. You can also do that.

A flange stopper 22 is detachably fixed to the upper end of the support shaft 21, and a flange stopper 23 is fixed to the lower end of the support shaft, both of which are appropriately larger than the guide hole 19.

24 is a casing to prevent the wall of the borehole from collapsing;
It is press-fitted into the ground by the swinging pushing device 25.

The operation of this device will be explained next.

First, the wires 9, 9, 16 and 16 are wound up to raise the shaft guide block 15 and the drive unit 7 to the top of the mast 2 as shown in Fig. set.

Next, the wires 9, 9, 16, and 16 are loosened to lower the shaft guide block 15 and the drive unit 7 as shown in Figure 5b, and the screw 14 is inserted into the casing 24 and grounded, completing the preparation for excavation.

In this case, the shaft guide block 15 is positioned below the upper end of the support shaft 21 by a distance S that is equal to or greater than the depth of excavation (1).

Next, the motor 5 is started to rotate the screw 14, and as shown in Figure 5C, excavation is started and the casing 24 is
It is expanding into the ground.

In this case the screw 14, the drive part 7 and the support shaft 2
The total weight of No. 1 acts as an excavation surface pressure, and the screw can easily penetrate into the ground.

In addition, since the frictional force between the shaft guide block 15 and the guide rails 3, 3 increases due to the excavation reaction force, it is difficult for the shaft guide block 15 to descend.
only to descend.

After one excavation (in the figure, the length of the casing 24 or the length of the screw 14), the rotation of the screw 14 is stopped, and the shaft guide block 15 and the drive unit 7 are raised as shown in Figure 5d. , the rice clew 14 is pulled out from inside the casing 24.

Then, the base machine 1 is rotated to remove the earth and sand attached to the screw 14.

Next, add new casing 2 to casing 24 built underground.
4', and perform drilling with the screw 14 and press-fitting the casing 24 and 24' in the same manner as above (5th
Figure e).

In this case the screw 14, the drive part 7 and the support shaft 2
1 are connected in a straight line, and the drive part 7 and the support shaft 21 are made smaller in diameter than the screw 14, so the drive part and the support shaft are connected to the casing 2 along with the screw
4,24'.

After one excavation, the screw 14 is extracted from the casings 24, 24' and the soil is removed as shown in Figure 5F.

By repeating the above operations, the shaft guide block 15 is finally lowered to the lowest limit of the mast 2 as shown in figure 5g, and the support shaft 21 is lowered from the block 15 to the lowest limit to perform excavation. As a result, as shown in Figure 5h, a vertical hole is excavated that is deeper by the length of the support shaft 21 than the excavation depth of one Sukunoyu.

If the excavation depth is further increased, a new support shaft 21' may be added to the support shaft 21.

In this case, for example, as shown in FIG. 6, a square shaft 28 protruding from the lower end of the new support shaft 21' is fitted into a square hole 27 provided at the upper end of the support shaft 21, and secured with a fixing screw 29. Take measures to connect.

In the above excavation operation, the screw 14 is not added,
Since this is intermittent excavation in which excavation and soil removal are repeated using a short, fixed length screw, the excavation rotational reaction force acting on the mast 2 is kept to a minimum.

A multi-stage telescopic shaft can also be used as the support shaft 21.

According to the excavator of this invention, the screw, the drive part, and the support shaft are connected in series and supported so as to be able to rise and fall.
Since only the excavation rotational reaction force is applied to the mast, the entire weight of the screw, drive unit, and support shaft can be directly applied as excavation surface pressure. It becomes possible to easily excavate underground under its own weight with a suitable excavation surface pressure.

Furthermore, according to the present proposal, when excavating a long shaft with a short screw of a certain length and adding a support shaft or using a telescopic shaft, when excavating a long shaft with a conventional earth auger, There is no disadvantage of increased excavation rotational reaction force due to the addition of screws,
It is possible to minimize the excavation rotational reaction force that always acts on the mast, and therefore it is possible to realize long and large diameter excavation with small excavation torque. Since the support shaft, drive part, and screw are connected in a straight line, the drive part can also enter the ground together with the screw.Therefore, there is no need for a gripping device for the drive part, making the entire device simple and practical. The effect is enormous.

[Brief explanation of the drawing]

The drawings show an embodiment of this invention, the first being a side view and the second being a side view.
The figure is an enlarged front view of the upper part, and Figure 3 is III-II of Figure 2.
4 is a sectional view taken along the line IV-IV in FIG. 2, FIGS. 5a to 5h are schematic sectional views showing the excavation process, and FIG. 6 is an enlarged partially cutaway front view of the additional part of the support shaft. It is. 2... Leader mast, 7... Drive unit,
14... Screw, 15... Shaft guide block, 19... Guide hole, 21...
...Support shaft.

Claims (1)

[Claims for Utility Model Registration] A drive unit is suspended from a mast so that it can be raised and lowered, a support shaft is fixed to the upper end of the drive unit, and a screw having a diameter larger than that of the drive unit and the support shaft is attached to the output shaft at the lower end. connecting the support shaft, drive unit, and screw in a straight line; attaching a guide block to the mast so that the shaft can move up and down; and inserting the support shaft into the shaft guide block in a slidable but non-rotatable manner. Excavator supported.