JPH0434204Y2 - - Google Patents

Description

[Detailed explanation of the invention] (Industrial application field) This invention relates to a three-shaft earth auger.The purpose of this invention is to allow the tip of the auger rod to hit hard rocks when excavating a continuous hole to form an earth retaining wall underground. To provide a triaxial earth auger which can surely prevent twisting of an auger rod when the auger rod collapses or when mortar in an excavation hole is hardened.

(Prior art) When forming an earth retaining wall underground, a plurality of holes are excavated in a line in the ground using an earth auger device, a cement mill is poured into the holes, and H-shaped steel etc. are cast. is being carried out.

When drilling multiple holes with an earth auger, it is more efficient to use a dual shaft earth auger equipped with multiple (3 or 4) auger rods than an earth auger equipped with only a single auger rod.

The mainstream of this multi-shaft earth auger device is a three-shaft one.

However, when one of the multiple auger rods hits an obstacle such as hard rock underground, the auger rod receives rotational resistance, and this rotational resistance causes the entire triaxial auger rod to move in the direction of excavation. In some cases, the force was applied in the torsional direction, making it impossible to form a proper drilling hole.

In order to solve these problems,
A multi-shaft earth auger as disclosed in Japanese Patent No. 163541 has been proposed.

This multi-shaft earth auger has a connecting pipe fitted into the central auger rod of the three auger rods, and a connecting member extending from the connecting pipe connects this connecting pipe to the auger rods on both sides. .

This connecting pipe is fitted into a housing into which the proximal ends of three auger rods are fitted.

When excavating using this multi-axis earth auger, the three auger rods are forcibly maintained in a parallel state, so even if, for example, one of the auger rods on either side hits an underground obstacle, this will not occur. All three auger rods will not be twisted by the load at the time.

(Problems to be Solved by the Invention) However, the multi-axis earth auger disclosed in the above publication has the following problems.

First, since the connecting member connecting the three shafts is provided at the tip end even further than the tip of the connecting pipe, this connecting member experiences resistance from the excavation and removal of soil during excavation, resulting in poor excavation efficiency.

Furthermore, the multi-shaft earth auger disclosed in the above-mentioned publication has the auger rods on both sides longer than the auger rod in the center, which causes the following problem.

That is, if the central auger rod is longer than the auger rods on both sides, the central auger rod will excavate before the auger rods on both sides.

The center auger rod is rotated by the direct transmission of the rotation of an electric or hydraulic motor, and the rotation of the motor is transmitted to the auger rods on both sides after being decelerated by a speed reduction device. It rotates at a lower speed than an auger rod.

Therefore, the rotational force of the central auger rod is stronger than the rotational force of the auger rods on both sides.

If the central auger rod hits an obstacle, the torsional force from hitting the obstacle will be transmitted to the auger rods on both sides, even though the connecting pipe is provided, because the central auger rod has a strong rotational force. It becomes easier.

Therefore, if the central auger rod, which has a strong rotational force, is longer than the auger rods on both sides, the entire auger rod may be twisted, making it impossible to form an accurate excavation hole, even if a connecting pipe is provided.

(Means for Solving the Problems) This invention consists of a drive device that is installed at the tip of a crawler and can move up and down along a vertical leader supported by a backstay, and a drive device that is connected to the drive device and connected to each other. In a triaxial earth auger having three parallel auger rods, the central auger rod is shorter than the auger rods on both sides, a casing is fitted over the central auger rod, and the proximal end of the casing is The casing is connected to the housing of the drive device, and the terminal end of the casing extends to just before the cutting blade formed at the tip of the central auger rod and is fitted therein, and the auger rods on both sides and the casing are connected at least to the tip of the casing. The above-mentioned problems of the prior art are solved by a three-shaft earth auger characterized in that the three-shaft earth auger is connected by a connecting member extending from the casing and surrounding each auger rod at the middle and middle portions of the auger rod.

(Function) A casing is fitted over the auger rod at the center of the three-shaft earth auger, and the base end of this casing is connected to the housing of the drive device, so that one of the auger rods is inserted into the ground during excavation. Even in the case of hitting an obstacle, the rotational resistance is received by the casing.

Since the central auger rod is shorter than the auger rods on both sides, even if the central auger rod, which has the strongest rotational force, is subject to strong rotational resistance, the auger rods on both sides will have a deeper part than the central auger rod, so to speak. Since the excavation is carried out on its own, it has never experienced twisting due to the rotational resistance.

The casing fits up to just before the excavation blade formed at the tip of the central auger rod, and the tip of the casing is connected by a connecting member, so the part fitted to the casing is There is no need for a connecting member on the tip side, so there is no reduction in excavation efficiency due to an unnecessary connecting member being provided at the tip of the auger rod.

(Example) Hereinafter, a three-axis earth auger according to this invention will be explained based on the drawings.

FIG. 1 is a side view of the triaxial earth auger according to this invention, and FIG. 2 is a front view of the same.

The three-axis earth auger 1 includes a movable crawler 2, backstays 3, 3 mounted on both left and right sides of the crawler 2, and a leader provided at the tip of the crawler 2 and supported by the backstays 3, 3. 4, a drive device 6 that can move up and down along the guide 5 of the leader 4, and three auger rods 7a, 7b, 7a connected to the drive device 6 and parallel to each other.

The drive device 6 is a hydraulic or electric motor.

A housing 8 is attached to the lower part of the driving device 6 as shown in an enlarged view in FIG.

This housing 8 has three auger rods 7.
Holes 8a and 8b are formed for connecting a and 7b.

Auger rods 7a, 7a are connected to the holes 8a, 8a on both sides of these holes.

An auger rod 7b is connected to the central hole 8b.

The starting end of the casing 9, into which the central auger rod 7b is fitted, is connected by bolts to a flange 8c formed at the periphery of the central hole 8a.

Further, a connecting member 10 for surrounding and connecting the auger rods 7a, 7a on both sides and the casing 9 is provided at one location at the tip of the casing 9, and at two locations in the middle in this embodiment. The auger rods 7a, 7a and the casing 9 are connected (see FIG. 4).

12 is an auger steady rest device.

Incidentally, the auger rods 7a, 7a and the casing 9 are made into a long one by connecting a plurality of short auger rods or casing members in the longitudinal direction.

As shown in FIG. 4, screw-shaped excavation blades 13 are formed at the tips of the auger rods 7a and 7b, and above the excavation blades 13, an appropriate number of excavation blades 14 having a T-shaped cross section are formed.

The screw-shaped excavation blade 13 functions to dig underground, and the T-shaped cross-sectional excavation blade 14 mainly functions to mix the excavated soil and the cement mill.

In the central auger rod 7b, the digging blade 14 is formed only at the tip of the auger rod 7b, and the casing 9 is attached to the cutting blade 14.
It extends and fits right in front of the position where is formed.

The central auger rod 7b is shorter than the auger rods 7a, 7a on both sides, and is recessed above the position of the auger rods 7a, 7a on both sides.

Next, a description will be given of how underground excavation is performed using this triaxial earth auger 1.

First, the auger rods 7a, 7a on both sides dig into the ground, followed by the auger rod 7b in the center.

This excavation is carried out by transmitting the driving force of the drive device 6 to a gear (not shown), which rotates the central auger rod 7b, and also through gears (not shown) meshing with this gear. This is done by rotating the auger rods 7a, 7a in a decelerated state.

Since the auger rods 7a, 7a on both sides are connected to the casing 9 via the connecting member 10, even if either of the auger rods 7a, 7a hits an underground obstacle, the rotational resistance at that time will be reduced by the casing. You can take it at 9.

Furthermore, since the central auger rod 7b is shorter than the auger rods 7a on both sides, even if the central auger rod 7b, which has the most rotational force, hits an obstacle, the auger rods that have already dug further will still be able to dig further. 7a, 7a are 2 so to speak
Since the auger rod is shaped like a main leg and is dug with a force that resists the load at this time, no twisting occurs in the auger rod.

Further, the shaft connecting portion 10 includes auger rods 7a, 7.
Since it is not provided at the tip of b, the drilling hole can be formed smoothly.

(Effect of the invention) This invention consists of a drive device that is installed at the tip of the crawler and can move up and down along a vertical leader supported by a backstay, and three mutually parallel rollers that are connected to this drive device. In the triaxial earth auger, the central auger rod is shorter than the auger rods on both sides, a casing is fitted over the central auger rod, and the base end of the casing is connected to the housing of the drive device. and the terminal end of the casing is extended to just before the cutting blade formed at the tip of the central auger rod and is fitted therein, and the auger rods on both sides and the casing are connected at least to the tip and the middle part of the casing. Since the three-shaft earth auger is characterized in that the auger rods are connected by connecting members extending from the casing and surrounding each auger rod, the three-shaft earth auger has the following effects.

In other words, the central auger rod is shorter than the auger rods on both sides, and the casing is fitted over the central auger rod, so if either of the auger rods on both sides receives a load, the load will be borne by the casing. Tame 3
The entire auger rod of the book will not be twisted.

In addition, when the central auger rod receives a load, the auger rods on both sides dig further forward and form two legs, so the rotational resistance received by the central auger rod is transmitted to the auger rods on both sides. The three-axis earth auger performs proper digging without any problems.

Furthermore, since a connecting member is not provided at the tip of the auger rod, it eliminates the problem of poor excavation efficiency due to resistance from excavating and discharging soil due to the connecting member being provided at the tip as in the past. be done.

If such a triaxial earth auger is used for excavation work, an appropriate excavation hole can be formed quickly.

[Brief explanation of drawings]

Fig. 1 is a side view of the triaxial earth auger according to this invention, Fig. 2 is a front view of the same as above, Fig. 3 is a partially enlarged front view showing the part where the auger rod is connected to the drive device, and Fig. 4 is the auger rod. FIG. 2 is a partially enlarged front view showing a tip end and a midway part of. 1...Triaxial earth auger, 2...Crawler,
3... Backstay, 4... Leader, 6... Drive device, 7a, 7b... Auger rod, 8...
Housing, 9...Casing, 10...Connection member, 13, 14...Drilling blade.

Claims (1)

[Scope of utility model registration request] It has a drive device that can move up and down along a vertical leader supported by a back stay provided at the tip of the crawler, and three mutually parallel auger rods connected to this drive device. In a three-shaft earth auger, the central auger rod is shorter than the auger rods on both sides.
A casing is fitted over the central auger rod, the proximal end of the casing is connected to the housing of the drive device, and the terminal end of the casing extends just before the excavating blade formed at the tip of the central auger rod. The auger rods on both sides and the casing are connected to each other by connecting members extending from the casing and surrounding each auger rod at least at the tip and middle portions of the casing. Three-axis earth auger.