Guide rod anti-detachment safety device

Abstract

To prevent a guide rod having a telescopic structure for preventing co-rotation from coming off in a ground improvement machine or the like having a water swivel mechanism.SOLUTION: A pipe detection sensor (proximity switch) 41 detecting a lower end of an intermediate pipe 32 inside the lowermost (outermost) pipe 31 is attached to an upper part of the lowermost (outermost) pipe 31 of a guide rod 3. As shown in FIG. 1, when the guide rod 3 is contracted, the pipe detection sensor 41 detects an outer periphery 321 of the intermediate pipe 32, so the pipe detection sensor 41 is turned on. As shown in FIG. 2, the guide rod 3 extends by lowering a swivel head 21, and before the lower end 322 of the intermediate pipe 32 comes out of the lowermost pipe 31, the lower end 322 of the intermediate pipe 32 moves away from the pipe detection sensor 41, so the pipe detection sensor 41 is turned off.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a safety device for preventing the guide rod from coming off in a construction machine having a water swivel, for preventing the guide rod from rotating. More specifically, it relates to a safety device for preventing the guide rod from coming off in a guide rod having a telescopic structure.

Background Art

[0002] Due to the implementation of the "Housing Quality Assurance Promotion Act", it has become common to investigate the ground strength of the planned construction site in advance through a ground survey. As a result of this survey, in the case of "soft ground" where the ground strength is insufficient and the ground cannot support the building, a method of improving the soft ground into a strong ground by performing ground improvement work (columnar improvement, steel pipe piles, etc.) with a ground improvement machine is being carried out. This ground improvement machine supplies the pressurized liquid ground improvement material from the upper part of a tubular rotation-driven stirring shaft equipped with stirring blades at the lower part through a water swivel. The head at the upper part of the water swivel to which the hose for supplying the ground improvement material is connected rotates due to the rotation of the stirring shaft during the operation of ground improvement, so it is necessary to lock it so that it does not rotate.

[0003] For this reason, in Patent Document 1, a screw drive device (swivel head) is proposed in which the lower end of a rotation prevention member having a telescopic structure with tubular pipes stacked in multiple stages is fixed and mounted so that the head at the upper part of the water swivel does not rotate. Also, in Patent Document 2, a structure is proposed in which the large-diameter part of a multi-stage rod having a telescopic structure can penetrate through a connecting member connected to a swivel joint, so that it can expand and contract without increasing the number of stages of the multi-stage rod. In Patent Document 3, in the telescopic structure described in Patent Document 2, a stretching prevention member is arranged so that the small-diameter telescopic rod does not pop out during transportation or the like.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 7-233524 [Patent Document 2] Japanese Patent Publication No. 2009-203659 [Patent Document 3] Japanese Patent Publication No. 2015-30978 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The guide rod, which acts as a rotation-preventing member, extends when the stirring shaft chuck (the chuck that fixes the stirring shaft) of the swivel head (which is driven up and down along the leader to rotate the stirring shaft) is released, the swivel head is lowered, and the gripping position of the stirring shaft is changed. At this time, the operator works while visually checking the guide rod from above in the driver's seat to prevent it from coming out beyond its extension limit. However, depending on the model of the ground improvement machine, it may be difficult to check the guide rod from the driver's seat, and insufficient checking may result in the guide rod (the large-diameter section of the multi-stage rod) coming out. If the guide rod comes out, it is a dangerous job as it involves working at height. In addition, the guide rods are pulled up one by one from the small-diameter pipe in the center and extend, but if any of the guide rods get stuck midway due to a malfunction or other reason and continue to extend without fully extending, the guide rod may come out at a length shorter than the maximum extension, and there is a possibility that the guide rod will fall due to its own weight. The prior art described above cannot address these situations. The object of the present invention is to provide a guide rod detachment prevention safety device for a ground improvement machine or the like having a water swivel mechanism, which prevents the detachment of a telescopic guide rod used to prevent rotation. [Means for solving the problem]

[0006] To solve the aforementioned problems, the present invention employs the following means. In other words, the guide rod detachment prevention safety device of the present invention 1 is soil improvement machine The leader was erected and positioned there, Driven to move up and down along the leader A stirring blade for agitating and excavating the ground is attached to the lower end. hollow stirring shaft A swivel head for gripping and rotating, The aforementioned stirring shaft It is located on top of the above stirring shaft During rotational drive In the aforementioned hollow liquid substance Ground improvement material A water swivel to which an injection hose is connected in order to supply, A connecting member that holds the injection hose and is connected to the non-rotating part of the water swivel, It consists of a multi-tiered telescopic pipe structure, with the upper end of the top pipe being the connecting part. Material The lowest pipe is fixed to the swivel head, and the guide rod is extendable and retractable in the longitudinal direction of the leader. has soil improvement machine In, The lowermost pipe is located, The intermediate pipe located inside the lowest pipe Expand and contract Furthermore, it has a structure that allows only the intermediate pipe to be removed, and the removal of the intermediate pipe is The pipe detection sensor to be detected, Based on the signal from the pipe detection sensor, Intermediate The system detects abnormalities in pipe expansion and contraction and issues an alarm, and / or the aforementioned soil improvement machine It is characterized by comprising a safety control means for stopping the operation of the device.

[0007] The guide rod detachment prevention safety device of the present invention 2 is, in the present invention 1, the pipe detection sensor is the retractable moving Intermediate It is characterized by its ability to detect the lower end of a pipe. The guide rod detachment prevention safety device of the present invention 3 is characterized in that, in the present invention 1, the pipe detection sensor constantly detects the remaining length of the guide rod. The guide rod detachment prevention safety device of the present invention 4 is characterized in that, in the present invention 2, a plurality of pipe detection sensors are arranged spaced apart in the direction of extension and retraction of the guide rod. The safety device for preventing the guide rod from coming off according to the fifth aspect of the present invention is, in the second or fourth aspect of the present invention, characterized in that when the pipe detection sensor detects the pipe that moves telescopically, the safety control means stops the lowering of the swivel head.

[0008] The safety device for preventing the guide rod from coming off according to the sixth aspect of the present invention is, in the second or fourth aspect of the present invention, characterized in that when the pipe detection sensor detects an abnormality in the telescopic movement of the pipe, the safety control means displays a warning screen and sounds a warning buzzer. The safety device for preventing the guide rod from coming off according to the seventh aspect of the present invention is, in the third aspect of the present invention, characterized in that when the remaining length of the guide rod decreases, the safety control means stops the lowering of the swivel head. The safety device for preventing the guide rod from coming off according to the eighth aspect of the present invention is, in the third aspect of the present invention, characterized in that when the remaining length of the guide rod decreases, the safety control means displays a warning screen and sounds a warning buzzer.

Advantages of the Invention

[0009] The safety device for preventing the guide rod from coming off according to the present invention detects the position of the guide rod with a pipe detection sensor and stops the lowering operation of the swivel head before the guide rod comes off, so that it is possible to prevent the guide rod from coming off.

Brief Description of the Drawings

[0010] [Figure 1] FIG. 1 is an overall side view of a ground improvement machine equipped with the safety device for preventing the guide rod from coming off according to the first embodiment of the present invention. [Figure 2] FIG. 2 is an overall side view of a ground improvement machine showing a state in which an operation of lowering the swivel head to change the gripping position of the stirring shaft is performed in order to pull out the stirring shaft. [Figure 3] FIG. 3 shows the guide rod of FIG. 1, FIG. 3(a) is an enlarged perspective view of the guide rod, and FIG. 3(b) is an enlarged cross-sectional view taken along line A-A of FIG. 3(a). [Figure 4]FIG. 4 is a control block diagram of the guide rod removal prevention safety device according to the first embodiment of the present invention. [Figure 5] FIG. 5 is a flowchart showing the operation of the guide rod removal prevention safety device according to the first embodiment of the present invention. [Figure 6] FIG. 6 shows the pipe detection sensor of the guide rod removal prevention safety device according to the second embodiment of the present invention. FIG. 6(a) is an enlarged perspective view of the guide rod, and FIG. 6(b) is an enlarged cross-sectional view taken along line B-B of FIG. 6(a). [Figure 7] FIG. 7 is an enlarged cross-sectional view showing a guide rod removal prevention safety device using a wire type linear encoder according to the third embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0011] 〔First Embodiment of Guide Rod Removal Prevention Safety Device〕 Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. Figure 1 is an overall side view of a ground improvement machine equipped with a guide rod detachment prevention safety device of the first embodiment of the present invention, and Figure 2 is an overall side view of the ground improvement machine showing the state in which the swivel head is lowered to change the gripping position of the stirring shaft in order to pull out the stirring shaft. Figure 3 shows the guide rod of Figure 1, Figure 3(a) is an enlarged perspective view of the guide rod, and Figure 3(b) is an enlarged cross-sectional view of AA of Figure 3(a). Figure 4 is a control block diagram of the guide rod detachment prevention safety device of the first embodiment of the present invention, and Figure 5 is a flowchart showing the operation of the guide rod detachment prevention safety device of the first embodiment of the present invention. As shown in Figures 1 and 2, the construction machine of the embodiment of the present invention is a ground improvement machine 1, which has a vehicle body 12 that travels by a crawler device 11, and a columnar leader 13 that is mounted on the vehicle body 12 so as to be able to stand upright and tilt. A swivel head 21 is movably attached to the leader 13 and is raised and lowered by a hydraulic motor 22 at the upper end of the leader 13. The stirring shaft 24 is held in the stirring shaft chuck 23 of the swivel head 21, and the stirring shaft 24 is rotated by a rotary motor (not shown). The stirring shaft 24 is a hollow pipe, and stirring blades 25 attached to its lower end stir and excavate the ground. A water swivel 26 is attached to the upper end of the stirring shaft 24, and pressurized liquid ground improvement material is supplied to the stirring shaft 24 via the water swivel 26.

[0012] An injection hose 27, which supplies ground improvement material and is connected to a pressure pump, is connected to the upper head of the water swivel 26. A plate-shaped connecting member 28 is also fixed to the upper head of the water swivel 26, and the injection hose 27 is held by this connecting member 28. The guide rod 3 is composed of a telescopic pipe structure stacked in multiple stages (six stages in this embodiment of the present invention), and the upper end of the uppermost (innermost) pipe 36 is fixed to the connecting member 28. The lower end of the lowermost (outermost) pipe 31 of the guide rod 3 is fixed to the swivel head 21 with multiple bolts 37 (see Figure 3(a)). This guide rod 3 locks the upper head of the water swivel 26 so that it does not rotate together with the rotation of the stirring shaft 24 during ground improvement operation. Note that the structure and function of the water swivel 26 are well known and are not the essence of the present invention, so a detailed explanation of its structure and function will not be given.

[0013] In the state shown in Figure 1, the swivel head 21 is located at the upper end of the leader 13. To pull out the stirring shaft 24 from the state shown in Figure 1, it is necessary to lower the swivel head 21 to change the position in which the swivel head 21 grips the stirring shaft 24. To do this, first close the stirring shaft clamp 14 attached to the lower end of the leader 13 to grip the stirring shaft 24. Next, open the stirring shaft chuck 23 of the swivel head 21 to release the stirring shaft 24. Next, as shown in Figure 2, lower the swivel head 21 and then close the stirring shaft chuck 23 to grip the lower part of the stirring shaft 24. Next, open the stirring shaft clamp 14 at the lower end of the leader 13 to release the stirring shaft 24, and then raise the swivel head 21 to pull out the stirring shaft 24. As shown in Figure 2, when the swivel head 21 is lowered, the distance between the upper end of the stirring shaft 24 and the swivel head 21 increases, so the guide rod 3 extends. As shown in Figure 3, a pipe detection sensor (proximity switch) 41 is attached to the top of the lowest (outermost) pipe 31 of the guide rod 3 to detect the lower end of the intermediate pipe 32 located inside the lowest (outermost) pipe 31. As shown in Figure 1, when the guide rod 3 is retracted, the pipe detection sensor 41 detects the outer circumference 321 of the intermediate pipe 32, and therefore the pipe detection sensor 41 is ON.

[0014] As shown in Figure 2, when the swivel head 21 is lowered and the guide rod 3 extends, the lower end 322 of the intermediate pipe 32 separates from the pipe detection sensor 41 before the lower end 322 of the intermediate pipe 32 comes out of the lowest pipe 31, causing the pipe detection sensor 41 to turn OFF. As shown in Figure 3(b), a stepped portion 323 is formed on the inner circumference of the upper end of the intermediate pipe 32. Also, a protrusion 331 is formed on the outer circumference of the lower end of the intermediate pipe 33 which is above the intermediate pipe 32. Therefore, when the swivel head 21 is lowered and the guide rod 3 extends, the intermediate pipe 33 slides upward inside the intermediate pipe 32, but the protrusion 331 catches on the stepped portion 323 and pulls the intermediate pipe 32 upward, so the intermediate pipe 33 does not come out of the intermediate pipe 32. Because there are similar protrusions and steps between the uppermost pipe 36 and the intermediate pipe 35, between the intermediate pipe 35 and the intermediate pipe 34, and between the intermediate pipe 34 and the intermediate pipe 33, the guide rod 3 will not come out even if it extends. In other words, in order to prevent damage to the guide rod 3, connecting member 28, etc., only the intermediate pipe 32 inside the lowest pipe 31 of the guide rod 3 has a structure that allows it to come out of the lowest pipe 31 when it extends beyond its extension limit. Also, if any of the guide rods get stuck midway due to a malfunction or the like and continue to extend without fully extending, the intermediate pipe 32 may come out of the lowest pipe 31 at a length shorter than the maximum extension.

[0015] Figure 4 is a control block diagram of a guide rod detachment prevention safety device according to an embodiment of the present invention. As shown in Figure 4, the arithmetic unit 51 is connected to a ROM 52, RAM 53, display device 54, input device 55, output device 56, pipe detection sensor 41, etc. The ROM 52 stores the system program and data. The RAM 53 is loaded with the guide rod detachment prevention safety program 531, the construction support program 532, etc. The guide rod detachment prevention safety program 531 is loaded with a program to monitor guide rod detachment, display a warning on the display device 54, and sound a warning buzzer according to the detection result of the pipe detection sensor 41. The construction support program 532 is loaded with a construction support program for ground improvement. The arithmetic unit 51 controls the ground improvement machine 1 according to the system program stored in the ROM 52 and the program loaded in the RAM 53.

[0016] Next, the control operation of the guide rod detachment prevention safety device described above will be explained. Figure 5 is a flowchart showing the operation of the guide rod detachment prevention safety device according to an embodiment of the present invention. Figure 5 shows the operation of changing the gripping position of the stirring shaft 24 in order to pull out the stirring shaft 24 from the state shown in Figure 1. First, in step S10, the stirring shaft clamp 14 attached to the lower end of the leader 13 is closed to grip the stirring shaft 24. Next, in step S20, the stirring shaft chuck 23 of the swivel head 21 is opened to release the stirring shaft 24. Next, in step S30, the hydraulic motor 22 is activated to lower the swivel head 21 as shown in Figure 2. When the swivel head 21 is lowered, the distance between the upper end of the stirring shaft 24 and the swivel head 21 increases, so the guide rod 3 extends. If a malfunction or disconnection of the pipe detection sensor 41 is detected in step S31, in step S32, the hydraulic motor 22 is stopped to halt the descent of the swivel head 21, and a warning screen is displayed on the display device 54 with the messages "Abnormality detected in pipe detection sensor," "Swivel head descent operation is being restricted," and "Please check the pipe detection sensor." At the same time, a warning buzzer is sounded to notify the operator of the ground improvement machine 1.

[0017] As shown in Figure 3(b), when the guide rod 3 extends, the lower end 322 of the intermediate pipe 32 separates from the pipe detection sensor 41 before the lower end 322 of the intermediate pipe 32 comes out of the lowest pipe 31, causing the pipe detection sensor 41 to turn OFF (step S40). In step S50, the hydraulic motor 22 is stopped to halt the descent of the swivel head 21, and a warning screen is displayed on the display device 54 stating "Lower end of guide rod detected" and "Swivel head descent operation is being restricted." At the same time, a warning buzzer sounds to notify the operator of the ground improvement machine 1. As a result, it is possible to prevent the guide rod 3 from coming out, eliminating the risk of the guide rod 3 being damaged by the impact of falling due to a malfunction that prevented it from fully extending. In addition, safety is improved as it is possible to avoid the need to return the guide rod 3 to its original position at high altitudes. Subsequently, if the pipe detection sensor 41 turns ON in step S60, the swivel head 21 can be lowered in step S70.

[0018] [Second embodiment of the guide rod detachment prevention safety device] Hereinafter, a second embodiment of the present invention will be described based on the drawings. Figure 6 shows the pipe detection sensor of the guide rod detachment prevention safety device of the second embodiment of the present invention, where Figure 6(a) is an enlarged perspective view of the guide rod and Figure 6(b) is an enlarged cross-sectional view of BB in Figure 6(a). The guide rod detachment prevention safety device of the second embodiment of the present invention is an example in which two or more pipe detection sensors are installed and a step-by-step warning is displayed according to the remaining length of the guide rod. In the following description, only the parts that differ from the guide rod detachment prevention safety device of the first embodiment will be described, and the same parts as the guide rod detachment prevention safety device of the first embodiment will be given the same numbers. As shown in Figure 6, two pipe detection sensors (proximity switches) 411 and 412 are attached to the upper part of the lowest (outermost) pipe 31 of the guide rod 3 to detect the lower end of the intermediate pipe 32 located inside the lowest (outermost) pipe 31. The pipe detection sensors 411 and 412 are spaced apart in the extension and retraction direction (up and down direction) of the guide rod 3.

[0019] When the guide rod 3 is retracted, both pipe detection sensors 411 and 412 detect the outer circumference 321 of the intermediate pipe 32, so both pipe detection sensors 411 and 412 are ON. When the swivel head 21 is lowered and the guide rod 3 extends, and the lower end 322 of the intermediate pipe 32 moves away from the lower pipe detection sensor 411, the lower pipe detection sensor 411 turns OFF. At this point, the display device 54 displays a warning screen saying, "The remaining length of the guide rod is running low" and "Please be careful." When the swivel head 21 is lowered further and the guide rod 3 extends, the lower end 322 of the intermediate pipe 32 moves away from the upper pipe detection sensor 412 before the lower end 322 of the intermediate pipe 32 comes out of the lowest pipe 31, so the upper pipe detection sensor 412 also turns OFF. When this happens, the hydraulic motor 22 stops, stopping the descent of the swivel head 21, and the display device 54 displays a warning screen saying, "The lower end of the guide rod has been detected" and "The descent operation of the swivel head is being restricted." At the same time, a warning buzzer sounds to notify the operator of ground improvement machine 1.

[0020] [Third embodiment of the guide rod detachment prevention safety device] Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. Figure 7 is an enlarged cross-sectional view showing a guide rod detachment prevention safety device using a wire-type linear encoder according to the third embodiment of the present invention. The guide rod detachment prevention safety device of the third embodiment of the present invention is an example in which the remaining length of the guide rod 3 is constantly detected by a wire-type linear encoder, the remaining length of the guide rod 3 is constantly displayed on a display device 54, and a stepwise warning is displayed or the descent of the swivel head 21 is stopped according to the remaining length of the guide rod 3. The wire-type linear encoder body 42 is fixed to the upper part of the lowest (outermost) pipe 31 of the guide rod 3. The upper end of the wire 421 drawn upward from the wire-type linear encoder body 42 is attached to the upper end of the intermediate pipe 32 with a mounting bracket 422.

[0021] When the guide rod 3 is fully retracted, the display device 54 displays the maximum remaining length of the intermediate pipe 32. When the swivel head 21 is lowered and the guide rod 3 extends, reducing the remaining length of the intermediate pipe 32, the display device 54 displays a warning screen stating, "The remaining length of the guide rod is decreasing," and "Please be careful." When the swivel head 21 is lowered further and the guide rod 3 extends, the hydraulic motor 22 is stopped to halt the descent of the swivel head 21 before the lower end 322 of the intermediate pipe 32 comes out of the lowest pipe 31, and the display device 54 displays a warning screen stating, "The lower end of the guide rod has been detected," and "The descent of the swivel head is being restricted." At the same time, a warning buzzer sounds to notify the operator of the ground improvement machine 1. An optical sensor or an ultrasonic sensor may be used as the detection device that constantly detects the remaining length of the guide rod 3.

[0022] [Other embodiments] Although the above embodiment of the guide rod detachment prevention safety device of the present invention was applied to a ground improvement machine, it can also be applied to other construction machines such as boring machines as long as it has a water swivel structure. [Explanation of Symbols]

[0023] 1…Soil improvement machine 11... Crawler device 12... Vehicle body 13... Leader 14… Stirring shaft clamp 21... Swivel head 22… Hydraulic motor 23... Stirring shaft chuck 23 24… Stirring shaft 25…Agitator blades 26...Water swivel 27... Injection hose 28…Connecting member 3… Guide rod 31...Lowest (outermost) pipe 32, 33, 34, 35... intermediate pipes 321...Outer circumference of the intermediate pipe 32 322...Lower end of intermediate pipe 32 323... Step section 331... protruding part 36...Topmost (innermost) pipe 37... Bolts 41, 411, 412... Pipe detection sensors 42...Wire-type linear encoder main unit 421... Wire 422…Mounting hardware 51...Arithmetic device 52...ROM 53…RAM 531… Guide rod detachment prevention safety program 532…Construction support program 54…Display device 55...Input device 56…Output device

Claims

1. A leader erected and positioned on a ground improvement machine, A swivel head for gripping and rotating a hollow stirring shaft, which is driven to move up and down along the leader and has stirring blades attached to its lower end for stirring and excavating the ground, A water swivel is positioned above the stirring shaft and connected to an injection hose for supplying a liquid ground improvement material to the hollow space while the stirring shaft is rotating. A connecting member that holds the injection hose and is connected to the non-rotating part of the water swivel, It consists of a multi-stage stacked telescopic pipe structure, with the upper end of the top pipe fixed to the connecting member, the bottom pipe fixed to the swivel head, and a guide rod that can extend and retract in the longitudinal direction of the leader. In a ground improvement machine having, The lowermost pipe is positioned and has a structure that allows only the intermediate pipe to detach when the intermediate pipe located inside the lowermost pipe expands and contracts, and a pipe detection sensor detects the detachment of the intermediate pipe, A safety control means that detects abnormal expansion or contraction of the intermediate pipe based on a signal from the pipe detection sensor, issues an alarm, and / or stops the operation of the ground improvement machine. A guide rod detachment prevention safety device characterized by consisting of the following.

2. In the guide rod detachment prevention safety device according to claim 1, The pipe detection sensor detects the lower end of the intermediate pipe that is extending and retracting. A safety device to prevent guide rod detachment, characterized by the following features.

3. In the guide rod detachment prevention safety device according to claim 1, The pipe detection sensor continuously detects the remaining length of the guide rod. A safety device to prevent guide rod detachment, characterized by the following features.

4. In the guide rod detachment prevention safety device according to claim 2, Multiple pipe detection sensors are arranged spaced apart in the direction of extension and retraction of the guide rod. A safety device to prevent guide rod detachment, characterized by the following features.

5. In the guide rod detachment prevention safety device according to claim 2 or 4, The safety control means stops the descent of the swivel head when the pipe detection sensor detects the pipe moving in an extendable or retractable manner. A safety device to prevent guide rod detachment, characterized by the following features.

6. In the guide rod detachment prevention safety device according to claim 2 or 4, When the pipe detection sensor detects an abnormality in the extension and retraction movement of the pipe, the safety control means displays a warning screen and sounds a warning buzzer. A safety device to prevent guide rod detachment, characterized by the following features.

7. In the guide rod detachment prevention safety device according to claim 3, The safety control means stops the descent of the swivel head when the remaining length of the guide rod becomes short. A safety device to prevent guide rod detachment, characterized by the following features.

8. In the guide rod detachment prevention safety device according to claim 3, The safety control means displays a warning screen and sounds a warning buzzer when the remaining length of the guide rod becomes short. A safety device to prevent guide rod detachment, characterized by the following features.

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