Swivel corotation prevention device

Abstract

To reliably prevent corotation of a swivel and ensure safety during a work.SOLUTION: A device 1 for preventing corotation of a swivel 9 at the time when the rod 3 comprising the swivel 9 at an upper end is rotated. The device is composed of: a fixture 20 fixed to a non-rotating portion 9B of the swivel 9 and extending downward therefrom; a shaft member 21 fixed to a lower end of the fixture 20 and arranged in parallel to a rotation axis of the rod 3; and a driven rotating body 22 rotatably provided on the shaft member 21 and coming into contact with an outer surface of the rotating portion 9A of the swivel 9 to rotate in a driven manner by rotation of the rod 3. The driven rotating body 22 is pressed against an outer surface of the rotating portion 9A of the swivel 9 by interposing a spring member 26 between a frame 25 that fixes the shaft member 21 and the fixture 20.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a device for preventing co-rotation of a rod having a swivel at its upper end when the rod is rotated. [Background technology]

[0002] Conventionally, a ground improvement method has been known in which a drilling machine is used to penetrate the ground while rotating a rod, and a ground improvement material is injected to form a columnar improved ground. This type of ground improvement method includes a chemical injection method in which an injection material is infiltrated into the gaps in the ground and the interstitial water or air is replaced with the injection material, thereby binding the soil particles with the injection material and increasing the adhesiveness of the soil, and a high-pressure injection injection method in which a hardening material is injected into the ground at high pressure, and the kinetic energy of the injection body breaks and cuts the ground, and at the same time replaces or mixes the hardening material with the original ground and hardens it.

[0003] The upper end of the rod used in the chemical injection method and high-pressure jet injection method is equipped with a swivel to which an injection hose is connected, so that the injection material and hardener pumped out from the injection pump are supplied to the rod through the injection hose.

[0004] Various swivel rotation prevention devices have been developed to prevent the non-rotating part of the swivel to which the injection hose is connected from rotating with the rotating rod, causing the injection hose to become tangled and wrapped around the rod.

[0005] As such a co-rotation prevention device, for example, Patent Document 1 listed below discloses a structure in which a reaction force receiving arm is extended to the side of a fixed member of a swivel, one end of a wire is connected to this reaction force receiving arm and hung down, and a wire chuck device is provided in a drive unit for chucking the middle part of the wire. Patent Document 2 listed below discloses a device in which a cross member is attached to a swivel placed on the top of a rod, a mechanism is arranged to apply tension by wire from both ends of the cross member, and tension is applied to the wire to prevent the swivel from rotating. Patent Document 3 listed below discloses a structure in which a guide member that moves independently of the rotation drive device is provided in a leader, a telescopic member that can expand and contract is fixed to the swivel, and this telescopic member is integrated with the guide member via an intermediate support body to prevent co-rotation. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 10-220158 [Patent Document 2] Japanese Patent Application Publication No. 5-239983 [Patent Document 3] Utility Model Registration No. 3109482 Summary of the Invention [Problem to be solved by the invention]

[0007] In all of the co-rotation prevention devices described in Patent Documents 1 to 3, co-rotation is mechanically prevented by extending an arm, cross member, telescopic member, etc. from the swivel and supporting it on a fixed object, but if the arm, etc., protrudes too far from the swivel, it may be easily damaged by collision with other machines, in which case the co-rotation prevention function may not work. In addition, there are problems such as the long extended arm getting in the way during assembly and construction work, reducing safety.

[0008] SUMMARY OF THE PRESENT EMBODIMENTS Accordingly, a primary object of the present invention is to provide a device for preventing co-rotation of a swivel, which can reliably prevent the swivel from rotating together with a work piece and ensure safety during work. [Means for solving the problem]

[0009] In order to solve the above problem, the present invention according to claim 1 provides a device for preventing a swivel from rotating together with a rod having a swivel at its upper end when the rod is rotated, comprising: The present invention provides a device for preventing co-rotation of a swivel, characterized in that it comprises a fixed metal fitting fixed to the non-rotating part of the swivel and extending downward therefrom, an axial member fixed to the lower end of the fixed metal fitting and arranged parallel to the rotation axis of the rod, and a driven rotor rotatably mounted on the axial member and rotating in response to the rotation of the rod by contacting the outer surface of the rotating part of the swivel or the outer surface of the rod.

[0010] In the invention described in claim 1, a fixed metal fitting is fixed to the non-rotating part of the swivel, and an axial member arranged parallel to the rotation axis of the rod is fixed to the lower end of the fixed metal fitting, and a driven rotor rotatably provided on the axial member is adapted to rotate following the rotation of the rod by contacting the outer surface of the rotating part of the swivel or the outer surface of the rod. While the driven rotor rotates following the rotation of the rod, the contact position of the driven rotor is maintained in the same position, so that the non-rotating part of the swivel is reliably prevented from rotating together with the rotation of the rod. In addition, since the fixed metal fitting extends downward from the non-rotating part of the swivel and has a driven rotor at its tip, there is no part that protrudes significantly from the swivel, so that it does not get in the way during work and ensures safety during work.

[0011] The present invention according to claim 2 provides a swivel co-rotation prevention device as described in claim 1, in which the driven rotor is pressed against the outer surface of the rotating part of the swivel or the outer surface of the rod by interposing a spring member between a member fixing the shaft member and the fixed metal fitting, or by interposing a spring member between the non-rotating part of the swivel and the fixed metal fitting.

[0012] In the invention described in claim 2 above, by interposing a spring member at a specified position, the driven rotor is pressed against the outer surface of the rotating part of the swivel or the outer surface of the rod, preventing the driven rotor from slipping or spinning freely and making it easier to maintain the contact position of the driven rotor in the same position.

[0013] According to a third aspect of the present invention, there is provided the device for preventing co-rotation of a swivel as described in the first aspect, wherein the driven rotor is a roller.

[0014] In the invention described in claim 3, a roller made of rubber, plastic or the like is used as the driven rotor.

[0015] The present invention relates to claim 4, and there is provided a swivel co-rotation prevention device as described in claim 1, wherein the driven rotor is a gear, and a gear portion that meshes with the gear is formed on the outer surface of the rotating part of the swivel with which the driven rotor contacts or on the outer surface of the rod.

[0016] In the invention described in claim 4 above, a gear is used as the front vertical driven rotor, and a gear portion is provided on the outer surface of the rotating part of the swivel or the outer surface of the rod with which this gear meshes. Effect of the Invention

[0017] As described above in detail, according to the present invention, the swivels can be reliably prevented from rotating together, and safety during work can be ensured. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a side view of an improved device 2 equipped with a swivel co-rotation prevention device 1 according to the present invention. [Diagram 2] This is a procedure diagram for the ground improvement method. [Diagram 3] 1 is an enlarged cross-sectional view of a device 1 for preventing co-rotation of a swivel according to the present invention (enlarged view of part III in FIG. 1). [Figure 4] FIG. 4 is a top view of FIG. [Diagram 5]4 is a view taken along line VV in FIG. 3. [Figure 6] 2 is a cross-sectional view of the driven rotor 22 at a contact point. FIG. [Figure 7] FIG. 11 is an enlarged cross-sectional view of a swivel co-rotation prevention device 1 according to a modified example. [Figure 8] FIG. 8 is a top view of FIG. [Figure 9] 9 is a view taken along line IX-IX in FIG. 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0020] As shown in FIG. 1, a swivel co-rotation prevention device 1 according to the present invention is used in an improvement device 2 used in a ground improvement method such as a chemical injection method or a high-pressure jet injection method.

[0021] As the improvement device 2, a normal boring machine (hole-boring machine) for boring holes in the ground can be widely adopted. The improvement device 2 shown in FIG. 1 includes a rod 3 with a bit at its tip (lower end), a spindle 4 with a chuck for gripping the rod 3, a drive transmission unit 5 with a gear group and a clutch, a hydraulic motor 6 rotated by hydraulic energy, and a hydraulic unit 7 and a power board 8 for supplying hydraulic pressure for driving the hydraulic motor 6. The drive transmission unit 5 rotates the spindle 4 and moves it up and down by the rotation of the hydraulic motor 6, and the rod 3 is rotated to excavate the ground with the bit attached to its tip. When excavating with the bit, mud water pumped from a mud water tank (not shown) is sprayed from the tip of the bit via the swivel 9 and the rod 3 from a joint 10 or 11 to which an injection hose provided on the swivel 9 at the upper end of the rod 3 is connected, in order to cool the bit and to transport the excavated soil to the ground.

[0022] Here, the procedure of the ground improvement method using the improvement device 2 will be described with reference to Fig. 2. Fig. 2 shows the construction procedure of the chemical injection method as an example of the ground improvement method. Here, the chemical injection method will be described as an example, but the high-pressure jet injection method can also be constructed by the usual procedure.

[0023] Figure 2 shows the construction procedure for the double-pipe strainer method (multi-phase type), which is one of the chemical injection methods. The double-pipe strainer method first pumps in a fast-setting chemical solution to block areas where the chemical solution is likely to be artificially disturbed, and this packing effect prevents the next chemical solution from diffusing, after which a slow-setting chemical solution is injected, allowing for uniform penetration into the gaps between soil particles in required areas.

[0024] In the first step of the concrete construction procedure, as shown in FIG. 2(A), a hole is drilled to a predetermined depth while drilling water is sprayed from the tip of the rod 3.

[0025] Next, as the second step, as shown in Fig. 2(B), a primary injection is performed in which a quick-setting chemical liquid (liquid A) is injected from an injection hose connected to a joint 10 of a swivel 9 provided at the upper end of the rod 3. This seals the periphery of the injection pipe and performs rough injection.

[0026] Then, as the third step, as shown in Fig. 2(C), a secondary injection is performed in which a slow-setting chemical solution (liquid B) is injected from an injection hose connected to the swivel joint 11. This allows the chemical solution to penetrate uniformly into the gaps between the soil particles.

[0027] In the fourth step, as shown in FIG. 2(D), the rod 3 is pulled out stepwise in a range of 20 to 50 cm, and the second and third steps are repeated each time to inject the drug solution into a predetermined area.

[0028] The swivel rotation prevention device 1 of the present invention is a device for preventing the part of the swivel 9 at the upper end to which the injection hose is connected from rotating with the rotation of the rod 3 when the rod 3 is rotated to drill a hole or pulled out, thereby maintaining a non-rotating state.

[0029] As shown in Figures 3 to 5, the co-rotation prevention device 1 is composed of a fixed bracket 20 fixed to the non-rotating part of the swivel 9 and extending downward therefrom, an axial member 21 fixed to the lower end of the fixed bracket 20 and arranged parallel to the rotation axis of the rod 3, and a driven rotor 22 rotatably mounted on the axial member 21 and contacting the outer surface of the rotating part of the swivel 9, thereby rotating in response to the rotation of the rod 3.

[0030] 6, in the co-rotation prevention device 1, the driven rotor 22 in contact with the outer surface of the rotating part 9A of the swivel 9, which rotates in conjunction with the rotation of the rod 3, rotates in the opposite direction to the rotation direction of the rod 3. At this time, while the driven rotor 22 rotates in conjunction with the rotation of the rod 3, the rotation speed of the driven rotor 22 becomes the same as the rotation speed of the rod 3, and the driven rotor 22 is held in the same position, unless the resistance force between the rotating part 9A and the non-rotating part 9B of the swivel 9 or the resistance force between the driven rotor 22 and the shaft member 21 becomes large. In this way, since the contact point of the driven rotor 22 is always held in the same position, the non-rotating part 9B of the swivel 9 is held in a fixed position, and the injection hose can be reliably prevented from being entangled and wrapped around the rod 3 due to co-rotation.

[0031] Furthermore, in the co-rotation prevention device 1 of the present invention, there are no components that protrude significantly from the outer periphery of the swivel 9 or that hang down significantly from the swivel 9, and the shaft member 21 and driven rotor 22 are attached to the fixed bracket 20, so that they do not get in the way during work and work can be carried out safely.

[0032] Furthermore, since the co-rotation prevention device 1 according to the present invention is not structured to be fixed to an external fixed body, the joints 10, 11 to which the injection hose provided on the non-rotating part 9B of the swivel 9 is connected can be fixed in a position facing in any direction. Therefore, there is no need to determine in advance the relationship between the direction in which the injection hose extends and the installation position of the improvement device 2, allowing for flexible work planning according to on-site conditions and improving workability.

[0033] The swivel 9 is composed of a rotating part 9A that is coaxially connected to the upper end of the rod 3 and rotates integrally with the rod 3, and a non-rotating part 9B that is placed above the rotating part 9A and has a bearing 12 between it and the rotating part 9A, thereby significantly reducing the transmission of rotational force from the rotating part 9A. The non-rotating part 9B is provided with joints 10 and 11 to which injection hoses for injecting chemical solutions (liquid A and liquid B) are connected.

[0034] The fixing metal fitting 20 is a metal fitting formed by bending a metal plate into a hook shape, with one end fixed to the outer surface of the non-rotating part 9B of the swivel 9 and the other end being a hanging free end. Two insertion holes for inserting a fixing bolt 23 are provided at the end fixed to the swivel 9 and spaced apart in the circumferential direction of the rod 3, while two insertion holes for inserting a connecting fixing bolt 24 of a member for fixing the shaft member 21 are provided at the other free end side and spaced apart in the circumferential direction of the rod 3.

[0035] The shaft member 21 and driven rotor 22 have a structure similar to that of a sliding door wheel, with the shaft member 21 straddling two opposing faces of a frame body 25 formed into a U-shaped cross section, and the driven rotor 22 being mounted on this shaft member 21 so as to be freely rotatable.

[0036] The frame body 25 for fixing the shaft member 21 may be fixed directly to the fixed metal fitting 20 by the fixing bolt 24, but it is preferable to interpose a spring member 26 between the frame body 25 and the fixed metal fitting 20 so that the driven rotor 22 is pressed against the outer surface of the rotating part 9A of the swivel 9, as shown in Figures 3 and 5. To explain in more detail, the shaft portion of the fixing bolt 24 is extended to dispose the frame body 25 away from the fixed metal fitting 20, and a coil spring (spring member 26) that fits around the shaft portion of the fixing bolt 24 is provided at this separated portion, thereby interposing the spring member 26 between the frame body 25 and the fixed metal fitting 20. To position the driven rotor 22 in a pressed state against the outer surface of the rotating part 9A of the swivel 9, the frame 25 is pushed outward against the biasing force of the spring member 26, while the driven rotor 22 is brought into contact with the outer surface of the rotating part 9A of the swivel 9, and then the nut screwed onto the tip of the fixing bolt 24 is adjusted to adjust the pressure of the pressurization.

[0037] In this way, the driven rotor 22 is pressed against the outer surface of the rotating part 9A of the swivel 9 by the biasing force of the spring member 26, so that the frictional force between the driven rotor 22 and the outer surface of the rotating part 9A of the swivel 9 increases, making it difficult for the driven rotor 22 to slip or spin freely between the driven rotor 22 and the outer surface of the rotating part 9A of the swivel 9, and making it easier for the driven rotor 22 to be held in the same position. Even if a protrusion is formed on the outer surface of the rotating part 9A of the swivel 9 or a foreign object is interposed between the driven rotor 22 and the outer surface of the rotating part 9A of the swivel 9, causing the driven rotor 22 to jump outward, the biasing force of the spring member 26 absorbs the impact and allows the driven rotor 22 to quickly return to the state in which it is pressed against the outer surface of the rotating part 9A of the swivel 9.

[0038] Such a mechanism for pressing the driven rotor 22 against the outer surface of the rotating part 9A of the swivel 9 can also be achieved by interposing a spring member 26 between the non-rotating part 9B of the swivel 9 and the fixed metal fitting 20, as shown in Figures 7 to 9. More specifically, as shown in Figures 7 and 8, the fixed metal fitting 20 is disposed away from the outer surface of the non-rotating part 9B of the swivel 9, a fixed bolt 23 is provided in the center, guide shafts 27, 27 are disposed on both sides of the fixed metal fitting 20, and a coil spring (spring member 26) is fitted onto the guide shaft 27 between the fixed metal fitting 20 of the guide shaft 27 and the outer surface of the non-rotating part 9B of the swivel 9. At this time, the frame 25 and the fixed metal fitting 20 are directly fixed by the fixed bolt 24. In this embodiment, the fixing bracket 20, frame 25, shaft member 21 and driven rotor 22 are integrally subjected to the biasing force of the spring member 26, so that the driven rotor 22 is pressed against the outer surface of the rotating portion 9A of the swivel 9.

[0039] The illustrated driven rotor 22 is a roller made of rubber, plastic, metal, etc. This driven rotor 22 is subject to wear due to contact with the outer surface of the rotating part 9A of the swivel 9, so it is subject to periodic maintenance and replaced with a new one as necessary.

[0040] A gear may be used as the driven rotor 22. This gear is an external gear that rotates around the shaft member 21 as a rotation axis, and a gear portion that meshes with this gear is formed on the outer surface of the rotating part 9A of the swivel 9 with which this gear comes into contact. By using a gear as the driven rotor 22, the driven rotor 22 can reliably rotate following the rotation of the rotating part 9A without slippage or misalignment occurring with the outer surface of the rotating part 9A of the swivel 9.

[0041] [Other examples] In the above embodiment, the driven rotor 22 is disposed so as to be in contact with the outer surface of the rotating portion 9A of the swivel 9. However, it may be disposed so as to be in contact with the outer surface of the rod 3. [Explanation of symbols]

[0042] 1...Swivel co-rotation prevention device (co-rotation prevention device), 2...Improvement device, 3...Rod, 4...Spindle, 5...Drive transmission part, 6...Hydraulic motor, 7...Hydraulic unit, 8...Power board, 9...Swivel, 10, 11...Joint part, 12...Bearing, 20...Fixed metal fitting, 21...Shaft member, 22...Driven rotor, 23, 24...Fixed bolt, 25...Frame, 26...Spring member

Claims

1. A device for preventing a swivel from rotating together with a rod having a swivel at its upper end when the rod is rotated, comprising: A swivel co-rotation prevention device characterized by comprising: a fixed bracket fixed to the non-rotating part of the swivel and extending downward therefrom; an axial member fixed to the lower end of the fixed bracket and arranged parallel to the rotation axis of the rod; and a driven rotor rotatably mounted on the axial member and rotating in response to the rotation of the rod by contacting the outer surface of the rotating part of the swivel or the outer surface of the rod.

2. 2. The swivel co-rotation prevention device of claim 1, wherein the driven rotor is pressed against the outer surface of the rotating part of the swivel or the outer surface of the rod by interposing a spring member between the member fixing the shaft member and the fixed metal fitting, or by interposing a spring member between the non-rotating part of the swivel and the fixed metal fitting.

3. 2. The device for preventing co-rotation of a swivel according to claim 1, wherein said driven rotor is a roller.

4. 2. The device for preventing co-rotation of a swivel as described in claim 1, wherein the driven rotor is a gear, and a gear portion that meshes with the gear is formed on the outer surface of the rotating part of the swivel or the outer surface of the rod with which the driven rotor contacts.

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