JP3264645B2 - Structure of drive unit of Keriba - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cast-in-place pile construction machine,
For example, it relates to a construction machine according to the earth drilling method. As shown in FIG. 11, the surface of the hole wall is protected by surface casing a, and the lower part of the hole is protected by mud pressure or a stabilizing liquid such as bentonite.
lly-bar) (drive shaft for rotating the bucket of an earth drill) b.
Excavation is performed by rotating with bull d. The excavated earth and sand enters the drilling bucket c and is discharged to the surface of the earth. The present invention relates to the structure of the driving section of the keyer b.

[0002]

2. Description of the Related Art In FIG. 8, reference numeral 1 denotes a keyer. The keyer bar 1 has only two or three lock portions (three in the figure) per lock member. For this reason, since the position where the lock is applied is limited, it is difficult for the driver to understand. A drive plate 3a welded to the inner wall of the outer pipe 3 is provided at one position at the lower end of the outer pipe 3, and FIGS.
As shown in (1), it engages with the locking portion 2 of the rib provided on the outer wall of the inner pipe 4 which engages with the driving plate 3a provided on the inner wall of the outer pipe 3. At this time, the first stage button
When the cover is lowered to the lock position, the lock is rotated clockwise. During the clockwise rotation, the rotary table is lowered to engage the drive plate 3a with the lock portion 2 provided on the rib. Was. Therefore, at the time of locking, the drive plate 3a and the lock portion 2
In this case, a high surface pressure is generated, and the engaging portion is often deformed. Conversely, the lock may be released due to vibration during excavation or the like.

[0003]

(1) The lock is not easily released, and the excavation torque and the thrust force are reliably transmitted to the lower end bucket. (2) The lock portion is provided over the entire length of the keriba. (3) Locking at a plurality of locations at the time of locking to reduce the contact pressure on the contact surface, eliminate deformation of the contact surface, and improve durability. It is an object of the present invention to provide a structure of a driving unit which can be used.

[0004]

SUMMARY OF THE INVENTION A drilling machine for drilling by rotating a drilling tool 11 provided at the lower end of the drilling machine by means of a nesting type kelly bar 7 comprising a plurality of concentric tubes. The teeth 8a forming the outer rack 8 fixed to the outer wall of each tube forming the bar have an upper surface 8'a which forms a horizontal surface, a lower surface 8 "a which forms an inclined surface having an obliquely upward angle [theta]. The teeth 9a constituting the inner rack 9 provided on the inner wall are inclined surfaces having an upper surface 9'a with a taper angle .theta.
a forms a horizontal plane, the upper surface and the lower surface of the teeth constituting the rack are connected by vertical walls 8c, 8d, 9c, 9d to form a plurality of saw-toothed engaging portions, and the longitudinal direction of each concentric tube The inner and outer racks are provided at equal intervals circumferentially.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will be given with reference to FIGS.
FIG. 1 shows a portion of the inventive carryr 7 in a working state. FIG. 2 is a partially enlarged view of the rack applied to the keriba, and shows a part viewed from an arrow A in FIG. FIG. 3 shows a cross-sectional view of a tube constituting the kaver. FIG. 4 shows a cross section of the kerry in operation. FIG. 5 also shows a state in which the racks are engaged during the operation. Figure 6 shows the button when not engaged
1 shows a cross section of a tube constituting a bath. FIG. 7 shows a detailed view of the rack in a non-meshed state.

FIG. 1 shows a telescoping keriba 7 consisting of a plurality of concentric tubes 7a, 7b, 7c,..., Wherein the diameter of each tube is gradually reduced from the outer tube to the inner tube and then to the inner tube. ing.
Each of the kerbers 7 has an outer rack 8 arranged outside of each tube at 120 ° intervals over the entire length of the tube.
Also, three inner racks 9 are provided on the inner side.
They are arranged every 0 °. A flange 10 (FIG. 1) is fixed to an end of each shaft.

[0007] The outer rack 8 and the inner rack 9 which are arranged at equal intervals (three in the figure) on the inner wall side and the outer wall side are attached to the kerry bar 7 by welding. The outer rack 8 is installed over the entire length of each tube constituting the keriba, and the inner rack on the inner wall side has a length (about 1.
5m).

As shown in FIG. 1, for example, the multi-stage type kerry bar 7 is engaged with an outer rack 8 of a lower inner kelly bar 7a and an inner rack 9 of an outer kelly bar 7b fitted on the upper portion thereof. Excavation torque and thrust force are transmitted to the excavation tool 11 at the tip in the same meshing relationship as the number of steps of the bar, and excavation is performed.

The inner rack 9 and outer rack 8 of the kerry bar
Are sawtooth-shaped, equidistant teeth having a horizontal surface and a tapered surface, respectively, and lock by rotating the keriba in the direction of excavation while lowering the keriba. On the other hand, when the lock is released, the lock is easily released by reversely rotating the screw while slowly lowering it. More specifically, as shown in FIG.
Is a tape whose upper surface 8a 'is horizontal and whose lower surface 8a "is obliquely upward.
The angle θ. 7, the upper surface 9a 'of the teeth 9a of the inner rack 9 has an obliquely downward taper angle .theta. And the lower surface 9a "forms a horizontal plane. The upper surface 8a' of the teeth of the outer rack 8 is shown. And the lower surface 8a "are connected at the leading end by a vertical surface 8c and at the base by a vertical surface 8d, and the upper surface 9a 'and the lower surface 9a" of the teeth of the inner rack 9 are connected by a vertical surface 9c at the leading end and a vertical surface 9d at the base. Connected by vertical walls, these teeth are equally spaced over the entire length of the concentric tube.

Note that the shape of the upward tapered surface on the lower surface of the outer rack 8 and the shape of the downward tapered surface on the upper surface of the inner rack 9 can be curved.

(About the engagement between the outer rack 8 and the inner rack 9) As shown in FIGS.
In this case, the inner rack 9 of the outer keriba and the outer rack 8 of the inner keriba engage. It is necessary to raise and lower the keriba by the interval of the rack simultaneously with the rotation.

In the case of disengagement, as shown in FIGS. 6 and 7, the keriba is slightly wound up, and the lock is released by rotating the keriba in a direction reverse to the direction of digging (arrow b in FIG. 6).

Although the description has been given of the kerber in the above description, the present invention can also be applied to a construction machine for digging while excavating and contracting the ground excavating force (torque and thrust force) of the multistage bar.

[0014]

As described above, since a rack having a plurality of teeth composed of an inclined surface and a horizontal surface and a vertical wall connecting them is provided inside and outside each tube constituting the keriba, a lock at the time of locking is provided. In the excavation rotation direction, the teeth of the rack bite, the rotational torque acts on the vertical tooth surface of the inner rack, and the thrust force acts on the horizontal tooth surface of the inner and outer racks. When the lock is released, the tape is attached by reverse rotation, so that the tape is easily released. Further, since the inner and outer racks are provided at equal intervals over the entire length of the kerry bar, the operation is reliable and the lock does not come off.

[Brief description of the drawings]

FIG. 1 shows the lower end of a telescopic keriber according to the invention.

FIG. 2 is an enlarged view of a rack provided in the kerry bar, as viewed in the direction of arrow A in FIG. 1;

FIG. 3 is a cross-sectional view of the kerry.

FIG. 4 is a cross-sectional view of the kerry bar during operation.

FIG. 5 shows an engaged state during work.

FIG. 6 is a cross-sectional view of the keriba when it is not engaged.

FIG. 7 shows a state when the dog is engaged.

FIG. 8 is an overall view of the keriba.

FIG. 9 is a sectional view of a conventional driving unit.

FIG. 10 is a sectional view taken along the arrow X in FIG. 8;

FIG. 11 is a schematic view of a known earth drill method.

[Explanation of symbols]

7 (7a, 7b, 7c) Keriba 8 Outer rack 8a Teeth 9a (of inner rack) 8a 'Upper surface (of outer rack teeth) 9a' Upper surface 8a '(of inner rack teeth) Lower surface 9a ″ (of the teeth of the outer rack) Lower surface 8c, 9c, 8d, 9d Vertical surface (connecting the upper and lower surfaces of the teeth) 9 Inner rack 10 Flange 11 Drilling tools

Claims (1)

(57) [Claims] An excavating tool (11) provided at a lower end of a kerber (7) having a telescopic structure comprising a plurality of concentric tubes.
In the excavator which excavates by rotating the nest, the teeth (8a) constituting the outer rack (8) fixed to the outer wall of each tube constituting the nested keriba have an upper surface (8'a) in a horizontal plane,
The lower surface (8 "a) forms an inclined surface having an obliquely upward angle [theta], and the teeth constituting an inner rack (9) provided on the inner wall of the telescopic keriba.
(9a) is an upper surface (9'a) is an inclined surface having an oblique downward angle θ,
a) forms a horizontal plane, the upper surface and the lower surface of the teeth constituting the rack are connected by vertical walls (8c, 8d, 9c, 9d) to form a plurality of saw-toothed engaging portions, and each concentric tube Characterized in that the inner and outer racks are provided at equal intervals on the circumference over the longitudinal direction of the drive.