Expandable cutter structure for auger-type simple excavator

Abstract

To enable construction without providing an arrival shaft in a simple excavator construction method.SOLUTION: In a simple excavator A, an excavator body 3 is provided that can move freely on rails 2 installed inside a starting shaft 1, an auger 5 having a cutter body 13 at its tip is connected to the front of the excavator body 3, an outer periphery of the auger 5 is covered with a propulsion pipe 4, the excavator body 3 is moved forward on the rails 2 while the cutter body 13 is rotated to cut away earth and sand, and the cut earth and sand is discharged toward the starting shaft 1 through the propulsion pipe 4, thereby propelling the propulsion pipe 4 into the ground, and two cutter pieces 14 of the cutter body 13 are journaled in a scissors-like manner to the cutter body 13. By rotating the auger 5 in one direction, the rear portions of the cutter pieces 14 are pushed forward, greatly expanding the diameter of the two cutter pieces 14, and by rotating the auger 5 in the other direction, the rear portions of the cutter pieces 14 are pulled backward, thereby reducing the diameter of the two cutter pieces 14.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] This invention relates to an expandable cutter structure in an auger-type simple excavator used when laying small-diameter pipelines underground, in which the cutter expands in diameter when excavating and contracts in diameter when retracted, allowing the cutter to pass through the pipeline. [Background technology]

[0002] In the conventional simple excavator method for laying small-diameter pipes, as shown in Figure 12, an excavator body 3 is slidably placed on rails 2 installed in a small starting shaft 1 (minimum length 1.2 m, width 1.0 m), and an auger 5 placed inside a jacking pipe 4 is rotated by a hydraulic motor (not shown) using the excavator body 3 to rotate a cutter 6 at the tip of the auger 5, thereby excavating the ground in front. The excavated soil is discharged into the starting shaft 1 using the space between the jacking pipe 4 and the auger 5 contained therein as a transport route.

[0003] Furthermore, the pushing of the propulsion pipe 4 is performed by an operator in the departure shaft 1 manually pushing down the operating lever 7 of the excavator body 3 using the principle of leverage. Because the propulsion pipe 4 is pushed into the ground manually in this way, the outer diameter of the excavation made by the cutter 6 at the tip of the auger 5 is slightly larger than the outer diameter of the propulsion pipe 4. Therefore, in the prior art, removing the equipment inside the propulsion pipe 4 required the work of detaching the cutter 6 from the auger 5 in the arrival shaft 8 after the pipeline tunnel had been penetrated. The hydraulic motor is connected to a hydraulic unit 9 located on the ground.

[0004] Patent Document 1 shows an example of such a simple excavator.

[0005] Furthermore, when laying underground power or communication pipes, a preliminary pipe may be laid in consideration of future road plans, etc. If this preliminary pipe can be laid using the open-cut method, the required area can be excavated from the ground surface, but if there are obstacles above ground that make the open-cut method inapplicable, the pipe jacking method is used. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Design Registration No. 1586636 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0007] However, the jacking method usually requires a starting shaft 1 to install the jacking device and an arrival shaft 8 to remove the cutter 6 for excavation, but obtaining road occupancy and obtaining consent from the customer takes time, which can lead to delays in the process.In the past, there have been cases where construction could not begin because the above permission could not be obtained.

[0008] When the above-mentioned process delays cannot be tolerated in underground pipeline installation work, the one-step press-in method of small-diameter pipe jacking is used, and construction is performed without setting up an arrival shaft 8, but because the one-step press-in method requires a larger jacking device than the auger method, there are cases where the starting shaft size cannot be secured due to underground obstacles, or construction time is delayed. As described above, with the simple excavator method, which allows construction from a small shaft, a way to avoid process delays caused by the inability to set up an arrival shaft 8 is required.

[0009] Therefore, in order to solve the above-mentioned problems, this invention aims to provide a structure in which, in a simple excavation machine construction method, it is possible to perform construction without setting up an arrival shaft, so that after excavation by the propulsion device is completed, all of the equipment inside the propulsion pipe can be pulled out toward the starting shaft, and the cutter that is interfering with this can be expanded in diameter to be larger than the outer diameter of the propulsion pipe during excavation, and can be reduced in diameter to be smaller than the inner diameter of the propulsion pipe after excavation is completed. [Means for solving the problem]

[0010] The invention of claim 1 is a simple excavator that has an excavator body that can move freely on rails installed inside a starting shaft, an auger with a cutter body at its tip connected to the front of the excavator body, the outer periphery of the auger covered with a propulsion pipe, the excavator body moving forward on the rails while the cutter body rotating to cut away earth and sand, the cut away earth and sand being discharged by the auger through the propulsion pipe toward the starting shaft and propelling the propulsion pipe into the ground, the cutter body has two cutter pieces journalled to the cutter body in a scissors shape, when the auger is rotated in one direction the rear parts of the cutter pieces are pushed forward and the two cutter pieces open, expanding their diameter to be larger than the outer diameter of the propulsion pipe, when the auger is rotated in the other direction the rear parts of the cutter pieces are pulled backward and the two cutter pieces close and become smaller in diameter than the inner diameter of the propulsion pipe, this is an expandable cutter structure in an auger-type simple excavator.

[0011] The invention of claim 2 relates to an auger tip body having a cylindrical housing with a tip opening, which is integrally provided at the tip of the auger, and the two cutter pieces are journaled at the front of the cutter body, and the rear of the cutter body forming a horizontal short columnar portion is inserted into the housing of the auger tip body so as to be freely rotatable in a spiral manner, and the central portions of the two cutter pieces are journaled so as to be freely rotatable on fixed shafts that are placed within central notches provided at the front end of the front of the cutter body, and an open-close bar protruding from the tip of the auger passes through the housing of the auger tip body and the short columnar portion of the cutter body and protrudes into the central notch, and two locking pins provided at the tip of the open-close bar are inserted into the The cutter structure in an auger-type simple excavator as described in claim 1 is configured such that the auger is inserted into a long hole rearward of the center, and rotation of the auger in one direction causes the short cylindrical portion to rotate spirally and enter the back of the storage compartment of the auger tip body, thereby moving the opening and closing rod forward relatively, and each of the locking pins at the tip of the opening and closing rod moves to the front of the long hole of each cutter piece, causing each cutter piece to rotate around the fixed shaft and open, and rotation of the auger in the other direction causes the short cylindrical portion to rotate spirally and move to the front of the storage compartment of the auger tip body, causing the opening and closing rod to retreat relatively, and each of the locking pins moves to the rear of the long hole of each cutter piece, causing each cutter piece to rotate around the fixed shaft and close.

[0012] In addition, the invention of claim 3 is an expandable cutter structure in the auger-type simple excavator described in claim 2, in which the configuration in which the short cylindrical portion of the cutter body is inserted into the storage compartment of the auger tip body so as to be freely spirally rotatable is provided with a spiral groove on the outer periphery of the short cylindrical portion of the cutter body, and a protruding pin is provided that protrudes into the storage compartment of the auger tip body and has its tip engaged with the spiral groove.

[0013] In addition, the invention of claim 4 is an expandable cutter structure for the auger-type simple excavator described in claim 1, in which a center bit is provided across the opening tip of the central cutout portion of the cutter body, and the front of each cutter piece is provided with a cross-sectional hook-shaped excavation cutter piece, and the rear is provided with a ring cutter piece. [Effects of the Invention]

[0014] According to the invention of claim 1, when burying small-diameter pipes using a simple excavator, the excavation outer diameter of the cutter body can be enlarged or reduced, so that after laying the thrust pipe to the desired location, the outer diameter of the cutter body can be made smaller than the inner diameter of the thrust pipe and the cutter body can be pulled back to the starting shaft through the pipeline, making it possible to construct the pipeline without setting up a destination shaft.

[0015] Furthermore, according to the invention of claim 2, the same effect as that of the invention of claim 1 can be obtained, and the operation of expanding and contracting the outer diameter of the two cutter pieces of the cutter body can be more reliably performed.

[0016] Furthermore, according to the invention of claim 3, a spiral groove is provided on the outer periphery of the short cylindrical portion at the rear of the cutter body, and a protruding pin is provided that protrudes into the storage compartment of the auger tip body and has its tip fitted into the spiral groove, so that the spiral rotation of the short cylindrical portion of the cutter body within the storage compartment of the auger tip body can be more reliably performed.

[0017] Furthermore, according to the invention of claim 4, a center pit is provided at the front end of the cutter body, and the front of each of the two cutter pieces has a cross-sectional hook-shaped excavation cutter piece, and the rear has a ring cutter piece, and by rotating these, the cutting body has a high stirring effect underground, and the thrust pipe can be easily thrust into the ground. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a partially sectional front view of a simple excavator having an expandable / contractable cutter according to a first embodiment of the present invention. [Figure 2] 1 is a plan view of an expandable / contractable cutter of a simple excavator according to a first embodiment of the present invention. FIG. [Figure 3] 1 is a front view of the expansion cutter of the simple excavator according to the first embodiment of the present invention in an expanded diameter state. [Figure 4] 1 is a side view of the expansion cutter of the simple excavator according to the first embodiment of the present invention in an expanded diameter state. [Figure 5] 1 is a front view of the expansion / contraction cutter of the simple excavator according to the first embodiment of the present invention in a contracted state. FIG. [Figure 6] 1 is a side view of the expansion and contraction cutter of the simple excavator according to the first embodiment of the present invention in a contracted state. [Figure 7] 1 is a cross-sectional view of an expandable cutter of a simple excavator according to a first embodiment of the present invention in an expanded diameter state. [Figure 8] 1 is a cross-sectional view of the expansion / contraction cutter of the simple excavator according to the first embodiment of the present invention in a contracted state. [Figure 9] 8 is a side cross-sectional view of the expansion cutter of the simple excavator according to the first embodiment of the present invention in an expanded diameter state, and is a cross-sectional view taken along the line AA in FIG. 7. [Figure 10] 8 is a side cross-sectional view of the expansion cutter of the simple excavator according to the first embodiment of the present invention in an expanded diameter state, and is a cross-sectional view taken along the line BB in FIG. 7. [Figure 11] 1 is a partial cross-sectional front view of a cutter body and an auger tip body of an expandable / contractable cutter of a simple excavator according to a first embodiment of the present invention. [Figure 12] FIG. 1 is a schematic diagram showing a conventional jacking method using a simple excavator. DETAILED DESCRIPTION OF THE INVENTION

[0019] (Embodiment Example 1) The expandable cutter B of the simple excavator A according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 11. FIG.

[0020] First, we will explain the simple excavator A. As shown in Figure 1, this simple excavator A has an excavator body 3 slidably mounted on rails 2 installed in a starting shaft 1. The excavator body 3 comprises a hydraulic motor 3a, a rotary power unit 3b, an operation switch 3c, and an operation lever 7, and these members are supported by a frame.

[0021] The shaft end 5a of the auger 5 is connected to the front of the rotary power unit 3b of the excavator main body 3. A plurality of augers 5 are connected at regular intervals and extend to the tip. A plurality of thrust pipes 4 are connected to the outer periphery of the auger 5 and are capped with the auger. The expanding / contracting cutter B of this invention is connected to the tip of the auger 5. These thrust pipes 4, augers 5, and expanding / contracting cutter B are inserted into the ground from the starting shaft 1. The thrust pipes 4 inside the shaft 1 are supported by a starting pipe base 25 as needed. Although not shown, the hydraulic motor 3a is connected to a hydraulic unit 9 located on the ground, as in Figure 12.

[0022] Next, we will explain the expanding / contracting cutter B. In this expanding / contracting cutter B, an auger tip body 12 is integrally provided at the tip of the auger 5, and this auger tip body 12 has a housing 11 with a cylindrical cross section and a tip opening. In addition, a cutter body 13 is provided that is supported by the auger tip body 12, and this cutter body 13 is composed of a front part that axially supports two cutter pieces 14, 14, and a rear part that forms a horizontally facing short cylindrical part 15.

[0023] A short cylindrical portion 15 at the rear of the cutter body 13 is inserted into the housing 11 of the auger tip body 12 so as to be freely rotatable in a spiral manner, and the central portions of the two cutter pieces 14, 14 are each rotatably supported on a fixed shaft 17 that is placed within a central cutout portion 16 provided at the front end portion of the front of the cutter body 13. The front and rear portions of each of these cutter pieces 14 protrude from the central cutout portion 16 to the outside of the cutter 13, and each cutter piece 14 has a cross-sectional hook-shaped excavating cutter piece 14a protruding from the front and an arc-shaped ring cutter piece 14b protruding from the rear.

[0024] An open-close bar 18 protrudes axially from the tip of the auger 5. The open-close bar 18 passes through a hole 11a in the housing 11 of the auger tip body 12 and a through-hole 15a that penetrates the short cylindrical portion 15 at the rear of the cutter body, protruding into the central notch 16. A T-shaped metal fitting 19, with both ends protruding perpendicularly to the open-close bar 18, is fixed to the tip of the central notch 16, and locking pins 20, 20 are provided on both ends of the T-shaped metal fitting 19. These locking pins 20, 20 protrude in opposite directions. A long hole 21 is provided rearward of the shaft portion of the fixed shaft 15 of each of the two cutter pieces 14, 14, and each locking pin 20 is movably fitted into the long hole 21.

[0025] 7 and 11, the short cylindrical portion 15 at the rear of the cutter body 13 is inserted into the housing 11 of the auger tip body 12 so as to be able to rotate helically. A spiral groove 22 is formed on the outer periphery of the short cylindrical portion 15, and a protruding pin 23 formed on the outer periphery of the auger tip body 12 protrudes into the housing 11 of the auger tip body 12 and is inserted into the spiral groove 22 of the short cylindrical portion 15. As a result, when the auger 5 is rotated, if the cutter body 13 is underground, the cutter pieces 14 of the cutter body 13 are resisted by the ground in front and do not move, but only the auger tip body 12 rotates, and the protruding pin 23 is guided by the spiral groove 22 to rotate helically, so that the short cylindrical portion 15 of the cutter body 13 advances or retreats while rotating helically within the housing 11 of the auger tip body 12. Furthermore, the cutter piece 14, which is prevented from rotating by the front ground, is structured so that when the protruding pin 23 reaches the end point of the spiral groove 22, the short cylindrical portion 15 of the cutter body 13 and the auger tip body become one, the rotational force of the auger 5 is transmitted, and the cutter piece 14 begins to rotate.

[0026] A center bit 24 is provided at the tip of the cutter body 13 so as to straddle the central notch 16 .

[0027] This expansion / contraction cutter B has the above-mentioned configuration, and during excavation, when the expansion / contraction cutter B is underground, the soil acts as resistance, and when the auger 5 rotates to the right, the protruding pin 23 on the auger tip body 12 moves down the spiral groove 22 in the short cylindrical section 15 at the rear of the cutter body 13, causing the short cylindrical section 15 to rotate spirally and enter the back of the storage shed 11 of the auger tip body 12, thereby relatively moving the opening / closing rod 18 forward, and each of the locking pins moves to the front of the long hole 21 of each cutter piece 14, causing each cutter piece 14 to rotate around the fixed shaft 17 and open, and the two cutter pieces 14 expand in diameter as shown in Figures 3 and 7.

[0028] In this manner, when the two cutter pieces 14 are expanded in diameter, the front and rear ends of each of the two cutter pieces 14 extend outward from the outer diameter of the thrust pipe 4, as shown in Figure 4, and the thrust pipe 4, which has an outer diameter smaller than the outer diameter of the cutter pieces 14 of this cutter body 13, can be thrust by the operator's manual power using the excavator main body 3.

[0029] When excavation is completed and the equipment inside the propulsion pipe 4 is to be removed, the auger 5 is rotated counterclockwise, causing the protruding pin 23 to move within the spiral groove 22, and the short cylindrical portion 15 of the cutter body 13 to move in the direction of pushing the auger tip body 12 forward of the storage shed 11, thereby relatively retracting the opening and closing rod 18, causing each of the locking pins 20 to move to the rear of the long holes 21 of each cutter piece 14, causing each cutter piece 14 to rotate around the fixed shaft 17 and close, and the two cutter pieces 14 to reduce in diameter as shown in Figures 5 and 8.

[0030] In this way, when the two cutter pieces 14 are in a reduced diameter state, as shown in Figure 6, the outer diameter of the front and rear ends of each of the two cutter pieces 14 becomes smaller than the inner diameter of the thrust pipe 4, and the expansion / contraction cutter B can be pulled back to the starting shaft 1 through the thrust pipe 4. After this, the work is completed by closing the end of the pipeline consisting of the thrust pipe 4 with an existing jig to prevent ground subsidence.

[0031] In the first embodiment described above, the short cylindrical portion 15 is enabled to rotate in a spiral manner within the housing 11 of the auger tip body 12 by fitting the protruding pin 22 that protrudes into the housing 11 of the auger tip body 12 into the spiral groove 23 drilled in the outer periphery of the short cylindrical portion 15 at the rear of the cutter body 13. However, instead of this, other structures may be used, such as providing an outer peripheral screw on the outer periphery of the short cylindrical portion 15 and an inner peripheral screw on the inner periphery of the housing 11, and engaging these to enable spiral rotational movement. [Explanation of symbols]

[0032] A Simple excavator B Expandable cutter 1. Departure shaft 2. Rails 3 Excavator body 3a Hydraulic motor 3b Rotating power section 3c Operation switch 4. Thrust pipe 5. Auger 5a Shaft end 6 Cutter 7 Operating lever 8 Arrival shaft 9 Hydraulic unit 11 Hangar 11a Hole 12 Auger tip body 13 cutter body 14 cutter piece 14a Excavation cutter piece 14b Ring cutter piece 15 Short cylindrical portion 15a Through hole 16 Central notch 17 Fixed shaft 18 Opening and closing rod 19 T-shaped metal fittings 20 locking pin 21 oblong hole 22 spiral groove 23 protruding pin 24 Center bit 25 Starting pipe base

Claims

1. In a simple excavator, an excavator body is provided that can move freely on rails installed inside a starting shaft, an auger having a cutter body at its tip is connected to the front of the excavator body, the outer periphery of the auger is covered with a propulsion pipe, the excavator body is moved forward on the rails while the cutter body is rotated to cut earth and sand, the cut earth and sand is discharged by the auger through the propulsion pipe toward the starting shaft, and the propulsion pipe is propelled into the ground. The cutter body has two cutter pieces journalled in a scissors-like manner, and by rotating the auger in one direction, the rear of each cutter piece is pushed forward, causing the two cutter pieces to open and expand to a diameter larger than the outer diameter of the propulsion pipe, and by rotating the auger in the other direction, the rear of each cutter piece is pulled backward, causing the two cutter pieces to close and contract to a diameter smaller than the inner diameter of the propulsion pipe.

2. An auger tip body having a housing with a cylindrical cross section and a tip opening is integrally provided at the tip of the auger, the two cutter pieces are journaled at the front part of the cutter body, and the rear part of the cutter body forming a horizontal short cylindrical portion is inserted into the housing of the auger tip body so as to be freely rotatable in a spiral manner, The central portions of the two cutter pieces are rotatably supported on a fixed shaft that is placed within a central notch provided at the front end of the front portion of the cutter body, an open-close bar that protrudes from the tip of the auger penetrates the storage compartment of the auger tip body and the short cylindrical portion of the cutter body and protrudes into the central notch, and two locking pins provided at the tip of the open-close bar are inserted into long holes behind the central portions of the respective cutter pieces, 2. The expandable / contractable cutter structure for an auger-type simple excavator according to claim 1, wherein rotation of the auger in one direction causes the short cylindrical portion to rotate spirally and enter the inner part of the storage compartment of the auger tip body, thereby moving the open-close bar forward relatively, and each of the locking pins at the tip of the open-close bar moves to the front of the long holes of each cutter piece, causing each cutter piece to rotate around the fixed shaft and open, and rotation of the auger in the other direction causes the short cylindrical portion to rotate spirally and move to the front of the storage compartment of the auger tip body, causing each of the open-close bar to retreat relatively, and each of the locking pins moves to the rear of the long holes of each cutter piece, causing each cutter piece to rotate around the fixed shaft and close.

3. 3. The expandable cutter structure in an auger-type simple excavator as described in claim 2, characterized in that the configuration in which the short cylindrical portion of the cutter body is inserted into the storage compartment of the auger tip body so as to be freely spirally rotatable is characterized in that a spiral groove is provided on the outer periphery of the short cylindrical portion of the cutter body, and a protruding pin is provided that protrudes into the storage compartment of the auger tip body and has its tip engaged with the spiral groove.

4. The expandable cutter structure for an auger-type simple excavator described in claim 1, characterized in that a center bit is provided across the opening tip of the central cutout portion of the cutter body, and the front of each cutter piece is a drilling cutter piece with a hook-shaped cross section, and the rear is a ring cutter piece.

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