JP3403820B2 - Pipe burial equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe burying apparatus for excavating underground and then inserting and burying a pipe. 2. Description of the Related Art As means for embedding water and sewer pipes, pipes for burying cables, and other pipes underground, an auger screw is inserted into a pipe to be buried conventionally (hereinafter referred to as a buried pipe). The excavation head provided at the tip of the auger screw excavates the tip ground, and the excavated earth and sand is conveyed to the starting pit side behind by the auger screw blades and discharged.
At the same time, a method is employed in which the back of the buried pipe is pressed and buried in the ground. In the pipe burying apparatus for burying a pipe as described above, for example, when the digging ground is a normal ground such as a viscous soil or a sand layer, digging is performed using a digging head having a digging bit fixed to a flat plate. In the case where the excavated ground is a hard ground such as a gravel layer or a bedrock, an excavator having an excavated head corresponding to the state of the ground is used, such as using an excavated head with a roller bit pivoted. [0004] However, in many cases, each of the above-mentioned excavating heads hardly exerts the excavating ability when excavating the ground having a geology other than the applicable geology. However, excavation efficiency is extremely reduced when a hard or soft stratum is included, and especially when digging ordinary ground with a digging head to which a roller bit is pivoted, the excavated soil often adheres and consolidates to the roller bit, making it impossible to dig. Had occurred. When the geology changes during excavation, it is not easy to replace the excavation head with one adapted to the geology.
There is a problem that the working efficiency is significantly reduced. [0006] In view of the above, an object of the present invention is to provide a pipe burying apparatus capable of efficiently excavating in accordance with the excavation of the ground in which the ordinary ground and the hard ground are mixed. I do. As a means for explaining the problems of the above prior art, the present invention provides a rotatable excavating rotary cylinder at the tip of a pipe to be buried, An auger screw that is rotatably driven through the pipe, and a plurality of roller bits for crushing gravels are rotatably mounted on the tip of the excavation rotary cylinder at circumferentially equal intervals,
An auger head for ordinary ground excavation is attached to the tip of the auger screw, and the auger screw is inserted through the excavation rotary cylinder in an axially slidable and non-rotating manner in the rotation direction. The roller bit is selectively positioned at a front or rear position. When the auger screw is retracted with respect to the buried pipe, the auger head for ordinary ground excavation at the tip of the auger retracts from the peripheral position of the roller bit of the excavation rotary cylinder, and the excavation of the gravel ground by the roller bit is performed. Since the roller bit is pivotally supported by the excavating rotary cylinder, the force (thrust) in the pushing direction of the buried pipe effectively acts on the gravel and easily crushes the gravel, and the crushed fragments are auger It is conveyed backward by the screw and discharged. When it is presumed from the excavation load, the contents of earth removal, the vibration sound and the like that the ground has changed to the normal ground, when the auger screw is advanced, the auger head at the tip of the auger screw moves forward from the peripheral surface position of the roller bit. The excavation can thus be carried out with the auger head by rotation of the auger screw. The present invention will be described below with reference to an embodiment shown in the drawings. FIG. 1 shows a cross section of a main part of a pipe burying apparatus according to the present invention, and FIG. 2 shows a front view. In FIG. 1, reference numeral 1 denotes a leading pipe connected to the tip of a not-shown buried pipe, and a cutting edge 2 is connected to the tip of the leading pipe 1 via a seal 3 so as to be able to oscillate at a slight angle. A plurality (usually four, up, down, left and right) of the hydraulic jacks 4, 4 of the direction correcting hydraulic jacks 4, 4 disposed inside the front conduit 1 are connected to the rear portion of the blade port 2, and The path measurement target 6 is monitored from the starting pit by transit or the like, and when the path is bent, pressure oil is supplied to predetermined direction correcting hydraulic jacks 4, 4,... To correct the direction of the blade port 2. It has become. An excavating rotary cylinder 7 is rotatably provided at the cutting edge 2. The excavation rotary cylinder 7 has a shaft cylinder portion 8 inserted into a fitting portion 9 formed in a circumferential direction on the distal end side of the blade port 2, and smoothly rotates through a bearing 10 and seals 11, 11. Kind of invasion. A plurality of (three in the figure) bearing portions 13 for mounting a roller bit 12 for crushing gravel are formed in the vicinity of the front outer periphery of the excavating rotary cylinder 7 at regular intervals in the circumferential direction. A roller bit 12 having a substantially conical peripheral surface of the bearing portion 13 on which carbide tips 14, 14.
Is rotatably mounted on a shaft 15 inclined so that a peripheral surface located on the front side thereof is located in a plane substantially perpendicular to the axis of the excavating rotary cylinder 7. On the other hand, an auger screw 17 is inserted into a cylindrical casing 16 which is provided from the buried pipe to the leading pipe 1 and the cutting edge 2, and the auger screw 17 is rotationally driven by a driving unit in a starting pit (not shown). At the same time as it moves forward and backward over a predetermined stroke. The tip of the casing 16 is fitted to the inner periphery of the blade 2 via a seal 18 to allow the blade 2 to swing. Near the tip of the auger screw 17, the excavating rotary cylinder 7 is inserted so as to be slidable in the axial direction and to rotate integrally with the rotating direction. In the illustrated embodiment,
A hexagonal shaft 19 having a predetermined length is joined near the tip of the auger screw 17, and this hexagonal shaft 19 is
Is slidably inserted into a bearing 20 having a hexagonal hole, whereby the rotational force of the auger screw 17 is transmitted to the drilling rotary cylinder 7. An auger head 21 for normal ground excavation is fixed to the tip of the auger screw 17. The auger head 21 is provided with the roller bit 1 as shown in FIG.
Excavating blades 24, 24,... Are fixed to the front surface of a flat base 23 having arms 22, 22, 22 extending to the vicinity of the outer periphery of the blade port 2 so as to avoid the positions of 2, 12, 12. A head 25 having a mountain-shaped cross section is provided at the center of the auger head 21. The head 25 has a plurality of holes 26, 26,.
The water supplied through the water supply pipe 27 is blown out as shown by arrows a and a in FIG. Next, the operation of the above embodiment will be described by taking as an example a case where the pipe is buried in the ground in the first half of the ground, in the gravel ground, and in the second half in the sand ground (normal ground). When excavating the gravel ground in the first half, when the auger screw 17 is retracted, the front surface of the auger head 21 is retracted from the position of the peripheral surface of the roller bit 12 of the excavation rotary cylinder 7 and returns to the state shown in FIG. I will Thus, when the auger screw 17 is driven to rotate, the rotation is transmitted to the excavating rotary cylinder 7 through the hexagonal shaft 19 and the bearing 20, and the excavating rotary cylinder 7 rotates to be rotatably supported by the roller bit 1.
2, 12 and 12 receive the force (thrust) in the pressing direction of the pipe to effectively act on the gravel, crush and subdivide the gravel, and auger screw 1
7 is conveyed backward by the blades 17a and discharged. During excavation of the gravel ground by the roller bits 12, 12,..., Water is injected from the tip of the auger head 21 through the water supply line 27 to cool the roller bits 12, 12,. Judging from the excavation load, earth removal contents, vibration noise, etc., when it is estimated that the ground has changed to sandy ground (normal ground),
The auger screw 17 is advanced. As a result, the hexagonal shaft 19 slides with respect to the bearing 20 of the excavating rotary cylinder 7 and the auger head 21 advances, and the excavating blade 2 of the auger head 21
Are projected forward by the peripheral surface of the roller bit 12 (see FIG. 3). If the excavation proceeds in this state, the excavation is performed by the auger head 21 and the roller bit 12 is hardly involved. When the earth removal is stagnated during the excavation and the excavation resistance and thrust increase, the inside of the blade port 2 or the casing 1
Since it is determined that the earth and sand have been compacted near the entrance of 6, the compacted state can be eliminated by sliding the auger screw 17 back and forth. As described above, according to the present invention, the excavation ground can be applied to the ground in which the ordinary ground such as the ordinary cohesive soil layer and the sand layer and the hard ground such as the gravel layer and the bedrock are mixed. At the time of drilling, the auger head is retracted for excavation of the hard ground, and excavation is performed with a roller bit.When excavating the ordinary ground, the auger head can be excavated with the auger head positioned ahead of the roller bit. Even if a different stratum exists, the work can be carried out without being excavated on any ground as in the related art. In addition, regardless of hard ground or ordinary ground, when earth and sand are compacted at the tip during excavation, the compaction can be released by moving the auger screw back and forth.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a main part showing an embodiment of a pipe burying apparatus according to the present invention. FIG. 2 is a front view of a main part showing one embodiment of the pipe burying apparatus according to the present invention. FIG. 3 is a sectional view showing a state where the auger head is advanced in FIG. 1; [Description of Signs] 1 tip conduit 2 blade port 4 hydraulic jack for direction correction 6 target for path measurement 7 excavation rotary cylinder 12 roller bit 16 casing 17 auger screw 19 hexagon shaft 21 auger head

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) E21D 9/08 E21D 9/06 311

Claims (1)

(57) [Claim 1] An excavating rotary cylinder rotatable at the tip of a pipe to be buried, and an auger screw rotatably inserted into the pipe to be buried, At the tip of the excavation rotary cylinder, a plurality of roller bits for crushing gravel are rotatably mounted at equal intervals in the circumferential direction, and an auger head for ordinary ground excavation is attached to the tip of the auger screw. The auger head is slidable in the axial direction and is inserted non-rotatably in the rotational direction, so that the auger head is selectively positioned at a front or rear position with respect to a roller bit. Pipe burial equipment.