JP7445539B2 - soil improvement machine - Google Patents

Description

The present invention relates to a soil improvement machine, and more particularly, to a soil improvement machine that improves the ground by stirring and mixing excavated earth and sand with an injected soil improvement agent.

In order to improve soft ground in construction and civil engineering work, ground improvement machines are used to harden the ground by injecting and stirring a ground improvement agent such as cement milk into an excavated hole. This type of ground improvement machine has a drilling head with a drilling blade and stirring blade attached to the lower end of a screw shaft, which is a hollow drilling shaft, and excavates the ground by lowering the rotating screw shaft along a leader. At the same time, the soil improvement agent sent through the screw shaft is ejected from the excavation head to stir the soil and the soil improvement agent (see, for example, Patent Document 1).

Japanese Patent Application Publication No. 2004-92302

The screw shaft is usually longer than the leader so that soil improvement can be carried out at a deeper depth, and a soil improvement agent injection hose (grout hose) is connected to a swivel joint at the upper end. However, since the connected injection hose has an unrestrained portion (slack) that follows the vertical movement of the screw shaft, this unrestrained portion is agitated by strong winds and comes into contact with the leader, causing friction and wear. There was a problem that the screws could get tangled with the screw shaft. Another possibility is to tie a rope to the unrestricted part and pull it from the ground, but this requires a worker and is costly.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a ground improvement machine equipped with a tensile force applying means capable of pulling an unrestrained injection hose to stabilize its position.

In order to achieve the above object, the ground improvement machine of the present invention lowers a hollow screw shaft having a drilling head attached to the lower end along the leader while rotatably driving the ground improvement machine, and also lowers the ground conveyed through the screw shaft. In a ground improvement machine that improves the ground by supplying an improvement agent to the excavation head and mixing the earth and sand excavated by the excavation blade of the excavation head with the soil improvement agent using the stirring blade of the excavation head, the screw shaft is An injection hose for feeding the ground improvement agent is connected to the upper end via a swivel joint, and the injection hose has a midway portion locked to a hose support member provided on the leader, and is connected to the swivel joint from the hose support member. It has slack by being connected to the joint without restraint, and includes a tensile force applying means that applies a downward tensile force to the lowest part of the slack , and the tensile force applying means has a slack by being connected to the joint without restraint. It is characterized in that it has a connecting device that engages with the device, and a reel device that winds up the rope whose tip end is fixed to the connecting device .

Further , the connecting tool is characterized in that it has a pair of upper and lower rotating rollers that sandwich the lowest part of the slack.

According to the ground improvement machine of the present invention, since it is equipped with a tensile force applying means that applies a downward tensile force to the lowest part of the slack of the injection hose, the injection hose can be poured in an unrestrained state without manual intervention. The hose can be tensioned to stabilize its position. Thereby, even if affected by strong winds, the injection hose can be protected from contact with peripheral structures such as the leader. In addition, since the tensioning force applying means has a coupling device that engages with the lowest part of the slack of the injection hose and a reel device that winds up the rope fixed to the coupling device, it is possible to pull the rope in the winding direction. , it becomes possible to keep the injection hose in a tensioned state at all times, and even if the position of the slack changes in the vertical direction, the tensioned state of the injection hose can be maintained. Furthermore, since the coupling device has a pair of upper and lower rotating rollers that sandwich the lowest part of the slack, relative movement between the injection hose and the coupling device is achieved smoothly, and thereby the tensile force applied to the injection hose is Force can be made more stable.

BRIEF DESCRIPTION OF THE DRAWINGS It is a side view of the ground improvement machine which shows one example of this invention. It is also a plan view. It is also a side view of the main part. Similarly, it is a plan view of the main part.

1 to 4 are diagrams showing a ground improvement machine of the present invention. As shown in FIGS. 1 and 2, the ground improvement machine 11 is a base machine composed of a lower traveling body 12 equipped with a crawler and an upper revolving body 13 rotatably provided on the lower traveling body 12. 14, a leader 15 erected at the front of the upper revolving body 13, and a leader undulating cylinder 16 that supports the leader 15 from the rear. In addition, a leader support 17 that supports the leader 15 so as to be able to rise and fall, and a pipe guide arm 18 that supports the pipe behind the leader 15 are provided at the front of the upper revolving body 13. Furthermore, a driver's cab 19 and a power unit 20 equipped with a hydraulic pump and the like are provided on both sides of the upper revolving body 13 in the vehicle width direction, and stabilizing jacks 21 are installed at four locations on the front, rear, left and right sides of the upper revolving body 13. In addition, a counterweight 22 for balancing the ground improvement machine 11 is mounted on the rear end of the upper revolving body 13.

The leader 15 is made by connecting a plurality of leader members each having a rectangular cylindrical cross section, and has a top sheave 23 on which a lifting rope is wound around the upper end, and a top sheave 23 on which a lifting rope is wound, and a rotationally driven construction member on the front of the lower part. Each member is equipped with an openable and closable steady stop device 24 to prevent vibration of the members, and a rack gear 25, which is one of the components of the rack and pinion lifting mechanism, is located in the center of the front of the leader 15, and a rack gear 25 is located at the front end of both sides. A pair of left and right guide pipes 26, 26 are provided continuously over the entire length of the leader 15, respectively.

The auger 27, which is an example of a rotational drive device, includes a chuck mechanism 27a for gripping and rotationally driving a penetrating work member, and a pair of left and right guide gibs 27b, 27b that slide in sliding contact with the guide pipes 26, 26 protrude rearward. The leader 15 can be moved up and down along the front surface thereof by rotationally driving a pinion gear that meshes with tooth rows provided on both sides of the rack gear 25 by an auger lifting motor 27c.

When performing ground improvement using the ground improvement machine 11, a screw shaft is used as a construction member. The screw shaft 28 is a hollow tube through which a soil improvement agent such as cement milk can be added, and has square shaft portions 28a that engage with the chuck mechanism 27a at multiple locations in the length direction including the upper end. A drilling head (not shown) having a drilling blade and a stirring blade is attached to the lower end. Further, a swivel joint 29 is attached to the upper end of the screw shaft 28, and an injection hose (grout hose) 30 is connected to the swivel joint 29.

Although not shown, in the swivel joint 29, a coupling connected to the screw shaft 28 and a body to which the injection hose 30 is connected are assembled so that they can rotate relative to each other, so that even when the screw shaft 28 rotates, the rotational force is This prevents it from being transmitted to the injection hose 30. However, since a leak-preventing seal is interposed between the coupling and the body, there is a risk that the body side will rotate due to the resistance of the seal portion. Therefore, a rotation prevention device is used to prevent the swivel joint 29 from rotating together.

In the detent device 31, a telescoping rod 31a that is extendable and retractable upward along the screw shaft 28 is fixed to the side surface of the auger 27, and the telescoping rod 31a and the swivel joint 29 are connected by a connecting member 31b. The connecting member 31b is connected to the coupling side of the swivel joint 29 via a bearing mechanism, so that the rotational force of the screw shaft 28 is not transmitted to the connecting member 31b. Further, the connecting member 31b is provided with a hose holding member 31c that holds the injection hose 30 in a connected state. As a result, the body side of the swivel joint 29 is held non-rotatably in a fixed position and is not rotated by the rotating screw shaft 28.

The injection hose 30 is a hose for supplying a ground improvement agent that is pumped from a batcher plant (not shown), and is formed into a long length by connecting multiple hoses of standard length, for example, 10 m. . The injection hose 30 is basically routed along the leader 15, and the middle part is locked to a hose support member 32 provided at the upper end of the leader 15, and the part beyond the hose support member 32 is connected to the hose support member 32. The portion is connected to the swivel joint 29 without restriction. This unrestricted portion has a substantially U-shaped slack 30a and is movable in the vertical direction following the vertical movement of the screw shaft 28, and its length is determined when the height position of the swivel joint 29 is the maximum. It is set according to the time of the year (Figure 1). Thereby, when the auger 27 equipped with the screw shaft 28 reaches the upper end (ascent limit position) or the lower end (descend limit position) of the leader 15, the shape of the slack 30a does not deform excessively.

In the ground improvement machine 11 formed in this manner, the screw shaft 28 is rotatable and movable up and down by the vibration damping device 24 in a state in which the intermediate angle shaft portion 28a of the screw shaft 28 is engaged with the chuck mechanism 27a of the auger 27. An injection hose 30 is connected to a swivel joint 29 held by a detent device 31 at the upper end of the screw shaft 28 . In this work start state, the screw shaft 28 is rotated and lowered along the leader 15, and the ground improvement agent sent through the screw shaft 28 is injected into the excavation hole from the tip of the excavation head. The earth and sand excavated by the excavation blade of the head and the ground improvement agent are mixed by the stirring blade of the excavation head.

Here, when the auger 27 reaches the lower end of the leader 15, the auger 27, which has released its grip on the intermediate corner shaft portion 28a, is raised to regrip the upper corner shaft portion 28a. At this time, the screw shaft 28 is gripped by the fixing means of the steady stop device 24 in order to fix the screw shaft 28 in that position. After the support position of the screw shaft 28 is switched to the upper side by moving the auger 27, the screw shaft 28 is lowered while being rotated, and the earth and sand excavated by the excavating blade and the ground improvement agent are mixed with the stirring blade. After the excavation head is lowered to a predetermined depth, the excavation head is pulled up in the reverse order to complete the ground improvement work.

By the way, due to the structure of the ground improvement machine 11, there is a risk that the unrestrained portion of the injection hose 30 may be agitated by strong winds and come into contact with the leader 15 or become entangled with the screw shaft 28. Therefore, for the purpose of ensuring the safety of the ground improvement work, the ground improvement machine 11 is equipped with a tensile force applying means that pulls the injection hose 30 in an unrestrained state to stabilize its position.

As shown in FIGS. 3 and 4, the tensile force applying means applies a downward tensile force to the lowest part L of the slack 30a in the injection hose 30, and engages with the lowest part L of the slack 30a. It has a connecting tool 33 and a reel device 34 that winds up a rope 34a whose tip end is fixed to the connecting tool 33 using the elastic force of a spring.

The connecting tool 33 includes a pair of upper and lower rotating rollers 33a, 33a that sandwich the injection hose 30, a bracket 33b that sandwiches and pivotally supports both the rotating rollers 33a, 33a, and a U-shaped U-shaped roller provided at the lower end of the bracket 33b. It has a rope attachment part 33c. The length and installation interval of both rotating rollers 33a, 33a are made to correspond to the outer diameter dimension of the injection hose 30, and when the coupling tool 33 is assembled to the injection hose 30 and engaged, the coupling tool 33 is attached to the injection hose 30. The rotation roller 33a that rotates on the surface allows the injection hose 30 to move in the length direction. That is, even if the position of the slack 30a of the injection hose 30 moves in the vertical direction, the connecting tool 33 remains at the lowest part L of the slack 30a while rotating the rotary roller 33a.

Directly below the slack 30a of the injection hose 30, the reel device 34 is arranged, which is bolted using the flange fastening portion of the jack 21. In this reel device 34, the rope 34a is wound around a rotating drum built into a reel body 34b. Further, the end of the rope 34a pulled out against the elastic force of the spring is fixed to the rope fixing portion 33c, and is always urged in the direction of winding into the reel body 34b. The winding force of the rope 34a can be increased or decreased by rotating an adjustment dial (not shown) to adjust the elastic force of the spring.

The tensile force applying means formed in this manner maintains a state in which tension is always applied so that the rope 34a does not loosen when the rope 34a is pulled out from the reel device 34 and the connecting tool 33 is engaged with the lowest part L of the slack 30a. Become. At this time, although a downward tensile force is applied to the lowermost portion L of the slack 30a, the injection hose 30 is placed in a tensioned state (tensioned state) to the extent that this portion is not strongly bent. During operation of the soil improvement machine 11, the slack 30a of the injection hose 30 is moved in the vertical direction following the vertical movement of the screw shaft 28 while maintaining its tensioned state.

As described above, the ground improvement machine 11 of the present invention is equipped with a tensile force applying means that applies a downward tensile force to the lowest part L of the slack 30a of the injection hose 30, so that no manual intervention is required. Instead, the injection hose 30, which is in an unrestricted state, can be tensed and its position stabilized. Thereby, even if affected by strong winds, the injection hose 30 can be protected from contact with surrounding structures such as the leader 15. In addition, since the tensile force applying means has a connecting device 33 that engages with the lowermost part of the slack 30a of the injection hose 30, and a reel device 34 that winds up the rope 34a fixed to the connecting device 33, the rope 34a can be It is possible to keep tension constantly applied by pulling in the winding direction, and even if the position of the slack 30a changes in the vertical direction, the tensioned state of the injection hose 30 can be maintained. Furthermore, since the connecting tool 33 has a pair of upper and lower rotating rollers 33a that sandwich the lowermost part L of the slack 30a, relative movement between the injection hose 30 and the connecting tool 33 is achieved smoothly, and thereby, The tensile force applied to the injection hose 30 can be made more stable.

Note that the present invention is not limited to the above-mentioned embodiments, and the tensile force applying means only needs to generate a tensile force that acts downward on the injection hose, and by pulling it from an angle other than directly downward. May be achieved. Further, the reel device can be constructed at low cost by being biased in the winding direction by a spring, but the winding force of the rope may be controlled by, for example, combining a clutch mechanism and an electric motor. Furthermore, if the diameter of the rotating roller is increased, the connector can be expected to have the effect of increasing the tensile force applied to the injection hose while preventing the hose from bending, and if the left and right rotating rollers are added separately, it can be With this engagement structure, smoother relative movement between the injection hose and the connector is realized. In addition, the reel body may be attached to a structure other than a jack, and various installation modes can be considered depending on the specifications of the soil improvement machine.

DESCRIPTION OF SYMBOLS 11... Ground improvement machine, 12... Lower traveling body, 13... Upper rotating body, 14... Base machine, 15... Leader, 16... Leader undulation cylinder, 17... Leader support, 18... Piping guide arm, 19... Operator's cab, 20 ...power section, 21...jack, 22...counterweight, 23...top sheave, 24...steady device, 25...rack gear, 26...guide pipe, 27...auger, 27a...chuck mechanism, 27b...guide gib, 27c...auger lifting/lowering Motor, 28... Screw shaft, 28a... Square shaft portion, 29... Swivel joint, 30... Injection hose, 30a... Slack, 31... Rotating device, 31a... Telescopic rod, 31b... Connection member, 31c... Hose holding member, 32 ... Hose support member, 33... Connector, 33a... Rotating roller, 33b... Bracket, 33c... Rope attachment part, 34... Reel device, 34a... Rope, 34b... Reel body

Claims (2)

A hollow screw shaft with a drilling head attached to the lower end is rotated and lowered along the leader, and the ground improvement agent sent through the screw shaft is supplied to the drilling head, and the drilling head is used for drilling. In a ground improvement machine that improves the ground by mixing earth and sand excavated with a blade and the ground improvement agent with a stirring blade of the excavation head,
An injection hose for feeding the soil improvement agent is connected to the upper end of the screw shaft through a swivel joint, and the injection hose has a midway portion locked to a hose support member provided on the leader, and the hose support having slack due to being connected from the member to the swivel joint without restraint;
comprising a tensile force applying means for applying a downward tensile force to the lowest part of the slack ,
A ground improvement machine characterized in that the tensile force applying means includes a connecting device that engages with the lowest part of the slack, and a reel device that winds up a rope whose tip end is fixed to the connecting device. . 2. The soil improvement machine according to claim 1 , wherein the connecting tool includes a pair of upper and lower rotating rollers that sandwich the lowest part of the slack.

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