JP6434883B2 - Jib for suspending underground continuous wall excavator and underground continuous wall excavation method - Google Patents

Description

  The present invention relates to a jib for suspending an underground continuous wall excavator that is used while being suspended from a jib of a base machine in order to excavate an excavation groove (element) for constructing an underground continuous wall, and an underground continuous With regard to the wall excavation method, in particular, the cycle time in excavation work is shortened and the excavation pitch is improved, so that the work efficiency is improved and the excavation in a deep region is also efficiently handled.

  The underground continuous wall is pre-fabricated in a drilling groove of a predetermined depth called an element drilled by opening and closing a bucket with a pair of left and right shells while using a stabilizing liquid to prevent the groove wall from collapsing It is a continuous reinforced concrete wall that is constructed in the ground by inserting a reinforced rod and placing a ready-mixed concrete using a tremi pipe. Its applications range from earthquake-resistant underground walls, underground body walls, foundations, circular shafts, underground tanks, earth retaining water walls, dam water walls, and many other applications.

  The underground continuous wall excavator is attached to a kelly bar equipped on a jib of a base machine such as a crawler crane (Patent Document 1), or is suspended from a jib via a wire and used instead of the kelly bar (Patent Document) 2, 3). All of these underground continuous wall excavators excavate excavation grooves of a predetermined depth by opening and closing the buckets by hydraulic cylinders, grabbing the earth and sand and discharging them to the ground. In addition, a special underground continuous wall excavator intended to excavate close to a retaining wall or an adjacent structure is also provided (Patent Document 3).

  The underground continuous wall excavator attached to the kelly bar shown in Patent Document 1 has a pair of shells attached to the excavator main body fixedly provided at the lower end of the kelly bar so as to be openable and closable, and the head side end portion of the excavator main body. The shells are individually opened and closed by a pair of hydraulic cylinders fixed to each other and having rod end portions fixed to the shell. That is, a pair of hydraulic cylinders are arranged in parallel at the left and right outer ends of the pair of shells, the shells are closed by extending the rods of the hydraulic cylinders, and the shells are opened by reducing the rods. (See FIG. 3 of Patent Document 1).

  Even in the underground continuous wall excavator suspended through wires as shown in Patent Documents 2 and 3, a pair of shells attached to the excavator main body suspended from the wire so as to be freely opened and closed are arranged on the head side end. Are fixed to the excavator body, and the shells are individually opened and closed by a pair of hydraulic cylinders each having a rod side end fixed to the shell. That is, a pair of hydraulic cylinders are arranged in parallel at the left and right outer ends of the pair of shells, the shells are closed by extending the rods of the hydraulic cylinders, and the shells are opened by reducing the rods. (See FIG. 1 of Patent Document 2 and FIG. 3 of Patent Document 3).

  Moreover, as shown in Patent Document 3, in order to excavate a place close to a retaining wall or an adjacent structure, the base machine boom for supporting the underground continuous wall excavator can be moved in the width direction. Provides means for expanding the excavable area from the position of the base machine.

JP-A-5-255932 JP-A-8-284200 JP-A-7-3831

  The underground underground wall can be constructed in advance from the ground to the underground wall, so application development has been attempted in many fields, not just the conventional earth retaining wall and water blocking wall, and its importance has increased. Yes. In addition, due to the deepening of underground structures and the increase in necessary seismic strength, the depth of 30m to 60m, which has been the main body of the past, has been increased to a greater depth, more specifically 60m to 100m. There is a demand for construction of a continuous underground wall having such a depth as to reach a depth of 100 m or more. At the same time, while maintaining excavation accuracy, the cycle time in excavation work is shortened, and the excavation pitch is improved to increase the number of excavations and the amount of excavated soil per unit time, thereby improving work efficiency. It is demanded to make it. The demand for improving the working efficiency becomes stronger as the depth of the excavation groove becomes deeper.

  The underground continuous wall excavator fixed to the Keriba as shown in Patent Document 1 can fix the inclination of the bucket at the time of excavation by using the Keriba, so the attitude of the underground continuous wall excavator is stable Although there is an advantage that excavation accuracy in the vertical direction can be maintained high, correction is difficult if the excavation groove is bent due to an obstacle or the like in the ground. Above all, Keriba is a heavy object consisting of multiple pipes, and the length that can be used is limited due to the direct winding capacity of the base machine, and it is not possible to drill beyond the length of Keriba. The depth is limited to about 40m. For this reason, it is impossible to meet the recent demand for deep excavation grooves.

  On the other hand, the underground continuous wall excavator suspended on the jib of the base machine as shown in Patent Documents 2 and 3 has a wire feed amount as long as it can be wound around the winch drum of the base machine. Since the weight is lighter than that of Keriba, it is possible to drill a deep trench. Therefore, in order to excavate a deep trench, it is necessary to presuppose that the underground continuous wall excavator is suspended by a wire having no length restriction. On the other hand, when the underground continuous wall excavator is suspended by wires, the excavation groove may be bent due to the soil or obstacles of the ground to be excavated. It is a new issue to take measures to correct it.

  Since the bucket of the underground continuous wall excavator is opened and closed by a hydraulic cylinder, it is necessary to supply hydraulic pressure and necessary power to the underground continuous wall excavator from a hydraulic unit equipped with a hydraulic pump and a hydraulic tank. Conventionally, underground underground wall excavators with a hydraulic unit mounted on the excavator body have also been provided, but there are restrictions on the capacity of the hydraulic unit's hydraulic tank etc. that can be mounted on the underground continuous wall excavator. In the space, sufficient external refrigerant necessary for heat exchange for cooling cannot be secured, and various problems occur due to heat generation. That is, when the hydraulic oil temperature rises, viscosity drop and component change occur, and cooling during excavation cannot often be performed sufficiently. For this reason, it is necessary to stop excavation due to the rise in the oil temperature, so that the excavation work is stopped, which directly affects the work efficiency.

  Therefore, the hydraulic unit and the excavator body are separated, the hydraulic unit is installed on the ground, and the hydraulic hose that is wound around the reel of the base machine is connected to the ground from the ground through the jib of the base machine, If the hydraulic pressure is supplied to the wall excavator, it is possible to employ a hydraulic tank having a sufficient capacity and various cooling means, and it is not necessary to suspend excavation for cooling the hydraulic tank. On the other hand, the length of the provided hydraulic hose for reel winding is limited, and the maximum length is about 65 m at present. Therefore, it is necessary to connect and use a plurality of hydraulic hoses in order to excavate a depth that reaches 100 m, and further a deep region that has a depth of 100 m or more. When the hydraulic hose is connected, it is inevitable that the connecting portion becomes a straight line of about 150 mm, and it becomes a new problem to smoothly feed and wind this straight portion through the jib.

  Furthermore, it is expected that the hydraulic hose and the cabtyre cable for supplying power will be subjected to a sudden load due to the operation of the underground continuous wall excavator and the time lag of the feeding / winding operation. The deeper the drilling groove, the higher the risk and the greater the load. Therefore, it is required as a new problem to provide an appropriate buffering means so that the hydraulic hose, the cabtyre cable and the like are not damaged by these loads.

  As shown in Patent Documents 1, 2, and 3, the pair of hydraulic cylinders for opening and closing the bucket of the underground continuous wall excavator are arranged in parallel at the left and right outer ends of the pair of shells. The rod is closed when the rod is extended, and the shell is opened when the rod is contracted. From the standpoint of improving work efficiency by shortening the excavation cycle time and improving the excavation pitch, the speed of raising and lowering the bucket into the excavation groove, the speed of opening and closing the bucket, and sediment in the bucket It is required to securely grasp. In this, the lifting speed of the bucket is solely due to the capacity of the base machine, so the bucket of the underground continuous wall excavator must both grasp the earth and sand as a gripping object and increase the opening and closing speed. It is required to achieve.

  In other words, the grabbing operation of the bucket requires a large opening / closing force (gripping force) when the load is large, such as when excavating earth and sand, especially hard ground. On the other hand, excavating soft ground or discharging grabbed earth and sand When the load is small, a large opening / closing force (gripping force) is not required, so priority should be given to improving the opening / closing speed. However, since the bucket of the conventional underground continuous wall excavator does not stand in this viewpoint, the opening / closing force (gripping force) and the opening / closing speed are not adjusted depending on the load applied to the bucket. . The conventional underground continuous wall excavator opens and closes at a constant speed on the premise of the required opening and closing force (gripping force) regardless of the load applied to the bucket, and requires a large opening and closing force (gripping force). The cycle time is longer due to the accumulation of bucket opening and closing times when the load is small. Therefore, in order to shorten the cycle time, it is a new problem to adjust the opening / closing force (grip force) and the opening / closing speed according to the hydraulic oil amount of the hydraulic cylinder according to the load applied to the bucket.

  In addition, since the conventional underground continuous wall excavator opens and closes the pair of left and right shells constituting the bucket individually with independent hydraulic cylinders, the left and right shells are blocked by obstacles such as underground rocks and gravel. There is a possibility that the opening and closing operations do not match, and the opening and closing operations are not performed smoothly. Further, since the pair of hydraulic cylinders are arranged in parallel at the outer ends of the shell in the left-right direction, there is a risk of being damaged by an underground obstacle or the like.

  For excavation of the excavation groove, the base machine that supports the underground continuous wall excavator is installed in a direction perpendicular to the excavation groove, so that the opening and closing direction of the bucket in the horizontal direction matches the width direction of the excavation groove. It is basic to perform excavation. However, in various excavation sites, when excavating a place close to a retaining wall or an adjacent structure, or due to the presence of an obstacle, the base machine may not be positioned so as to be positioned relative to the excavation groove (excavation position). Absent. Therefore, as shown in Patent Document 3, there is also provided means for enabling the boom for supporting the underground continuous wall excavator of the base machine to move in the width direction of the base machine, but the adjustable range is narrow, Further, it is necessary to add a moving means in the horizontal direction to the base machine, and a moving time in the horizontal direction is also required.

  If the base machine cannot be positioned with respect to the excavation groove, the position of the base machine is limited as long as the bucket can be rotated horizontally at the current position and the bucket can be suspended above the excavation groove. Therefore, the bucket can be easily positioned. Therefore, in order to shorten the cycle time, it is a new problem to accurately and easily control the posture of the bucket in the horizontal direction.

  Therefore, the present invention solves a new problem that the conventional underground continuous wall excavator and the underground continuous wall excavation method described above are required to solve, thereby maintaining the excavation accuracy and excavating cycle. For the purpose of providing a jib and underground continuous wall excavation method that suspends an underground continuous wall excavator that shortens time and improves work efficiency even in a deep region by improving the excavation pitch. Yes.

In order to achieve the object, the present invention provides a jib for hanging a continuous wall excavator for excavating a digging groove by opening and closing a bucket consisting of a pair of left and right shells by a hydraulic cylinder, and is installed on a tip frame of the jib. In addition to an arcuate guide frame with one end fixed to the base frame and the other end open, and a guide mechanism composed of a plurality of guide rollers mounted rotatably along the arc of the guide frame, A shock-absorbing hydraulic cylinder in which the rod-side end is fixed to the center of the bottom surface of the arc-shaped guide frame and the head-side end is fixed to the base frame, and an accumulator fixed to the base frame and storing hydraulic pressure from the buffering hydraulic cylinder equipped with a shock absorber made of, by supporting the pipe to be connected to the diaphragm wall excavator guide mechanism, normally Located rod extended state of衝用hydraulic cylinder, when more than predetermined load to the tube occurs, by reducing the rod by the load, the hydraulic pressure in the cushioning hydraulic cylinder to the pipe by flowing into the accumulator Underground continuous wall excavation in which the rod is extended by absorbing the load of the load with a shock absorber and supplying the hydraulic pressure in the accumulator to the buffer hydraulic cylinder with high-pressure gas when the load on the tube exceeds a certain level. The jib that suspends the machine is provided as a basis.

And the structure whose load is the impact which arises in a pipe body by the action | operation of an underground continuous wall excavator is provided.

Furthermore, a configuration in which the tube is a hydraulic hose for supplying hydraulic pressure to the underground continuous wall excavator and a configuration in which the tube is a cabtyre cable for supplying power to the underground continuous wall excavator are provided. To do.

Moreover, tubular body, to provide an arrangement which is flexible cable for supplying power to the hydraulic hose及beauty locations in the continuous wall excavator for supplying hydraulic pressure to the diaphragm wall excavator.

Then, the underground continuous wall excavator having the above-described configuration, in which the tubular body is a hydraulic hose for supplying hydraulic pressure to the underground continuous wall excavator and a cabtire cable for supplying power to the underground continuous wall excavator. The underground continuous wall excavator, which excavates the excavation groove by opening and closing a bucket consisting of a pair of left and right shells by a hydraulic cylinder, is suspended and supported by a suspension jib through a support line and guided from a hydraulic unit installed on the ground. By connecting the hydraulic hose supported by the mechanism to the underground continuous wall excavator, the hydraulic pressure is supplied to open and close the bucket, and the cabtyre cable supported by the guide mechanism is grounded from the power supply unit installed on the ground. by connecting to the middle continuous wall excavator, by supplying power to the diaphragm wall excavator, a drilling groove having a predetermined depth for constructing underground continuous walls, digging a stabilizing solution While preventing collapse of the excavation walls meet in the groove, in the underground continuous wall drilling method to drill, provides a diaphragm wall drilling method to alleviate and absorb the load on the hydraulic hoses and flexible cable with a buffer device To do.

  According to the present invention described above, since the underground continuous wall excavator is suspended from the jib of the base machine by the support rope such as a wire, the length of the support rope can be wound around the winch drum of the base machine. Since there is no restriction on the feed amount, the depth that exceeds the depth of about 30 m to 60 m, which has been the main body so far, more specifically, the depth that exceeds 60 m and reaches 100 m, and further, the depth of 100 m or more It is possible to excavate a deep trench such as

  The first hydraulic cylinder and the second hydraulic cylinder that open and close the bucket are arranged on the center line of the bucket and are provided at the center of the underground continuous wall excavator. Less risk. In addition, since the first hydraulic cylinder arranged in the upper stage and the second hydraulic cylinder arranged in the lower stage are arranged in series in the vertical direction with the rod side ends facing each other, the first hydraulic cylinder extends and the first hydraulic cylinder extends. When the two hydraulic cylinders are reduced, the bucket is closed, the first hydraulic cylinder is reduced, and when the second hydraulic cylinder is extended, the bucket is opened, so that the bucket can be opened and closed with the same thrust. In addition, since the shell opening and closing operations are performed in conjunction with the left and right in both the first hydraulic cylinder and the second hydraulic cylinder, the matching opening and closing operations are performed.

  Furthermore, the rod of the first hydraulic cylinder extends during the closing operation of the bucket, and the rod of the second hydraulic cylinder extends during the opening operation of the bucket. Therefore, the hydraulic pressure for extending the rods of the first hydraulic cylinder and the rods of the second hydraulic cylinder is set according to the excavation situation, that is, according to the degree of load applied to the bucket. The supply of hydraulic pressure by the differential circuit can be selected.

  That is, if the bucket is opened in a state where the load is small in the excavation groove, or if the bucket is opened to discharge the stored earth and sand, that is, when gripping force is not required and the opening and closing speed is given priority, differential Select the circuit and open the bucket. Similarly, when excavating soft ground with low excavation resistance, grabbing earth and sand with low excavation resistance, or closing an open bucket without grabbing earth and sand, that is, no gripping force is required, opening and closing speed is given priority. If so, select the differential circuit and close the bucket.

The front view of the state which closed the bucket of the underground continuous wall excavator. The side view of FIG. The front view of the state which opened the bucket of FIG. The whole side view which suspended and supported the underground continuous wall excavator to the base machine. Explanatory drawing of the principal part which shows the attachment state of a hydraulic cylinder. The front view of the main body frame which accommodated the sliding box. The AA expanded sectional view of FIG. The front view of a shell mounting frame. The front view of a connection frame. The principal part front view of an underground continuous wall excavator. Bucket operation explanatory drawing. Bucket operation explanatory drawing. Explanatory drawing of the normal circuit at the time of closing a bucket. Explanatory drawing of the differential circuit at the time of closing a bucket. Explanatory drawing of the normal circuit at the time of opening a bucket. Explanatory drawing of the differential circuit at the time of opening a bucket. Explanatory drawing of the turning mechanism of a bucket. Explanatory drawing of the turning mechanism of a bucket. Structure explanatory drawing of the jib tip of the base machine. Structure explanatory drawing of the jib tip of the base machine. Explanatory drawing of a buffer mechanism. Explanatory drawing of a buffer mechanism. Explanatory drawing of a posture correction apparatus. Explanatory drawing of a posture correction apparatus. Overall layout of the excavation site.

  Embodiments of a jib for suspending an underground continuous wall excavator according to the present invention and an underground continuous wall excavation method will be described below with reference to the drawings. FIG. 1 is a front view of the underground continuous wall excavator 1 according to the present invention with the bucket 10 closed, FIG. 2 is a side view thereof, FIG. 3 is a front view of the bucket 10 opened, and FIG. 4 is a base machine. FIG. The underground continuous wall excavator 1 is suspended from a jib 3 erected on a self-propelled base machine 2 such as a crawler crane by a support rope 4 such as a wire rope, and a bucket 10 comprising a pair of left and right shells 11 and 12. Is opened and closed by two hydraulic cylinders consisting of a first hydraulic cylinder 20 and a second hydraulic cylinder 30 to excavate the excavation groove.

  The pair of left and right shells 11 and 12 are pivotally supported by the connecting pin 15 at the lower end portion of the shell mounting frame 41, and one end of the tie rods 13 and 14 is pivotally connected to the upper surfaces of the shells 11 and 12. The other end of the tie rods 13 and 14 is pivotally supported by a connecting pin 49 in a sliding box 50 slidably installed in the main body frame 40 to which the shell mounting frame 41 is fixed. It is. Therefore, the bucket 10 consisting of a pair of left and right shells 11 and 12 can be opened and closed with the connecting pin 15 as a rotation center, and can be excavated and removed by the opening and closing operation, or the removed earth and sand can be discharged. .

  FIG. 5 is a main part explanatory view showing the mounting state of two hydraulic cylinders comprising the first hydraulic cylinder 20 and the second hydraulic cylinder 30, FIG. 6 is a front view of the main body frame 40 housing the sliding box 50, FIG. 6 is an AA enlarged sectional view of FIG. 6, FIG. 8 is a front view of a shell mounting frame 41, and FIG. 9 is a front view of a connecting frame 42 described later. 5 is shown as a perspective view in a state in which the main body frame 40 is extracted for the sake of explanation. The head side end portion 22 of the first hydraulic cylinder 20 is fixed to a connecting frame 42 fixed to the upper end portion of the main body frame 40 with a fixing pin 25, and the head side end portion 32 of the second hydraulic cylinder 30 is fixed to the lower end portion of the main body frame 40. Are fixed to the shell mounting frame 41 fixed to the upper end with a fixing pin 35, and the rod side end portion 21 of the first hydraulic cylinder 20 and the rod side end portion 31 of the second hydraulic cylinder 30 are opposed to each other in the vertical direction. The box 50 is fixed with fixing pins 26 and 36. Therefore, the sliding box 50 slides up and down in the main body frame 40 by the expansion and contraction of the rod 23 of the first hydraulic cylinder 20 and the rod 33 of the second hydraulic cylinder 30.

  The main body frame 40 is a hollow rectangular tube having a rectangular cross section and opened on both upper and lower surfaces, and windows 40a are formed on both the front and back surfaces so as to cover substantially the entire sliding range of the sliding box 50. The sliding box 50 is a rectangular parallelepiped block, and the entire area of both outer surfaces are in contact with both inner surfaces of the main body frame 40, and part of both outer surfaces are in contact with both inner surfaces of the main body frame 40. The body frame 40 can slide in the vertical direction. The sliding surfaces of the main body frame 40 and the sliding box 50 are inevitably worn out by the sliding operation. Therefore, a sliding plate 44 divided in two in the vertical direction is attached to the sliding surface of the main body frame 40, and a sliding plate 51 is detachably attached to the sliding surface of the sliding box 50, so that the degree of wear is reduced. They are exchanged accordingly (see FIG. 7). In the illustrated example, as the material of the sliding plate 51 attached to the sliding box 50, a material having a lower hardness than the sliding plate 44 attached to the main body frame 40 is used to promote wear of the sliding plate 51. ing. For this reason, the sliding plate 51 with high wear is mounted in a plurality of parts so that they can be partially replaced, and in the illustrated example, they are divided into eight parts (see FIG. 7).

  In the sliding box 50, pin holes 52 and 53 for fixing the rod side end portion 21 of the first hydraulic cylinder 20 and the rod side end portion 31 of the second hydraulic cylinder 30 are formed so as to face each other in the vertical direction. Has been. In addition, pin holes 54 and 55 for pivotally supporting the other ends of the tie rods 13 and 14 whose one ends are pivotally supported on the shells 11 and 12 are formed so as to face each other in the left-right direction. Therefore, the tie rods 13 and 14 are pivotally attached to the sliding box 50 and the shells 11 and 12 through the window 40a from the outside of the main body frame 40.

  On the outer periphery of the upper and lower ends of the main body frame 40, connecting flanges 45a each having a plurality of reinforcing ribs 46a are projected. Similarly, connecting flanges 45b each having a plurality of reinforcing ribs 46b are provided on the outer circumferences of the upper and lower ends of the connecting frame 42 shown in FIG. 9, and the main body is interposed via both flanges 45a and 45b. A connecting frame 42 is fixed to the upper portion of the frame 40 by bolts. The connection frame 42 is a hollow rectangular tube having a rectangular cross section and an open bottom surface, and is connected to the revolving frame 60 via an upper flange 46b. In FIG. 9, reference numeral 47 denotes a pin hole through which the fixing pin 25 for fixing the head side end portion 22 of the first hydraulic cylinder 20 to the connection frame 42 is inserted, and 42 a denotes the connection frame 42. It is the window part formed in both front and back.

  A connecting flange 45c is provided on the outer periphery of the upper end of the shell mounting frame 41 shown in FIG. 8 so that a plurality of reinforcing ribs 46c are erected, and the flange 45c and a flange formed at the lower end of the main body frame 40 are provided. The shell mounting frame 41 is connected and fixed to the lower part of the main body frame 40 with bolts via 45a. The shell mounting frame 41 is a hollow rectangular tube having a rectangular cross section and an open bottom surface, and 48 is a pin hole for fixing the head side end 32 of the second hydraulic cylinder 30 to the shell mounting frame 41. The fixing pin 35 is inserted. Reference numeral 49 denotes a pair of left and right pin holes, through which the connecting pins 15 for pivotally supporting the shells 11 and 12 to the shell mounting frame 41 are inserted, and 41 a is a window portion formed in the shell mounting frame 41.

  According to the first hydraulic cylinder 20, the second hydraulic cylinder 30, and the bucket 10 configured as described above, the rod 23 of the first hydraulic cylinder 20 expands, and the rod 33 of the second hydraulic cylinder 30 contracts to reduce the bucket 10. Closed (see FIG. 11), conversely, the rod 23 of the first hydraulic cylinder 20 contracts and the rod 33 of the second hydraulic cylinder 30 expands to open the bucket 10 (see FIG. 12). As described above, the underground continuous wall excavator 1 according to the present invention is configured so that two hydraulic cylinders including the first hydraulic cylinder 20 and the second hydraulic cylinder 30 are vertically moved with the rod side end portions 21 and 31 facing each other. The sliding box 50 is slid in the main body frame 40 by moving the rods 23 of the first hydraulic cylinder 20 and the rods 33 of the second hydraulic cylinder 30 in opposite directions. One feature is that the bucket 10 is opened and closed.

  In the underground continuous wall excavator 1 according to the present invention, the rod 23 of the first hydraulic cylinder 20 extends when the bucket 10 is closed, and the rod 33 of the second hydraulic cylinder 30 extends when the bucket 10 is opened. . Therefore, the hydraulic pressure for extending the rod 23 of the first hydraulic cylinder 20 and the rod 33 of the second hydraulic cylinder 30 depends on the excavation situation, that is, according to the degree of load applied to the bucket 10. It is possible to select between the hydraulic pressure supply by means of and the hydraulic pressure supply by the differential circuit.

  The differential circuit is a hydraulic circuit that feeds fluid to both ends of the actuator, and the fluid on the rod side loses due to the area difference of the cylinder, and then the fluid is added to the flow rate of the hydraulic pump and flows to the head side so that the actuator can move forward at high speed. It is. However, the thrust at this time is limited to the same thrust as the cylinder rod diameter because the same pressure is generated on the rod side. Therefore, the hydraulic circuit is effective when the speed of the rod is required rather than the thrust.

  In order to improve excavation efficiency, the bucket 10 is required to achieve both of reliably grasping earth and sand as a grasped object and increasing the opening and closing speed. That is, it is required to maintain a necessary opening / closing force when the load applied to the bucket 10 is large, and when the load is small, it is required to increase the opening / closing speed. In the present invention, since either the rod 23 of the first hydraulic cylinder 20 or the rod 33 of the second hydraulic cylinder 30 extends in both the opening and closing operations of the bucket 10, the differential in both the opening and closing operations of the bucket 10. It is possible to incorporate a circuit.

  FIG. 13 is an explanatory diagram when the bucket 10 is closed by a normal circuit giving priority to the opening and closing force. The hydraulic pump 56 supplies the hydraulic pressure to the head side of the cylinder 24 of the first hydraulic cylinder 20 and the cylinder 34 of the second hydraulic cylinder 30. Supplying to the rod side, the rod 23 of the first hydraulic cylinder 20 is extended, and the rod 33 of the second hydraulic cylinder 30 is reduced. The hydraulic pressure discharged from the rod side of the first hydraulic cylinder 20 and the head side of the second hydraulic cylinder 30 is returned to the tank 57 by the extension of the rod 23 and the reduction of the rod 33.

  Since the thrust generated by the supply of the hydraulic pressure is supplied only in the direction in which the bucket 10 is closed (the head side of the first hydraulic cylinder 20 and the rod side of the second hydraulic cylinder 30), the bucket 10 is a force corresponding to the supplied oil pressure. It is closed with. Therefore, when the load applied to the bucket 10 is large, such as when excavating the earth or sand, or grabbing the excavated earth or sand, that is, when the gripping force has priority over the opening and closing speed, the bucket 10 is closed by the above-described normal circuit.

  FIG. 14 is an explanatory diagram when the bucket 10 is closed by a differential circuit giving priority to the opening and closing speed. By supplying hydraulic pressure to both the head side and the rod side of the cylinder 24 of the first hydraulic cylinder 20 by the hydraulic pump 56. The rod side hydraulic pressure is pushed out by the head side hydraulic pressure due to the area difference of the cylinder 24 and is supplied to the head side. Therefore, the rod 23 is a hydraulic pressure obtained by adding the hydraulic pressure supplied to the rod side to the hydraulic pressure supplied to the head side. The stretching speed increases because of stretching. As the rod 23 of the first hydraulic cylinder 20 extends, the rod 33 contracts as the hydraulic pressure of the second hydraulic cylinder 30 is returned to the tank 57 and supplied to the rod side.

  The thrust of the rod 23 due to the supply of the hydraulic pressure is limited to the same thrust as the diameter of the rod 23 because the same pressure is generated also on the rod side of the first hydraulic cylinder 20. Therefore, when excavating soft ground with low excavation resistance, grabbing earth and sand with low excavation resistance, or when closing the open bucket 10 without grabbing earth and sand, that is, no gripping force is required, opening and closing speed is given priority. When the bucket 10 is to be closed, the bucket 10 is closed by the differential circuit described above.

  FIG. 15 is an explanatory diagram when the bucket 10 is opened by a normal circuit giving priority to the opening and closing force. The hydraulic pump 56 supplies the hydraulic pressure to the head side of the cylinder 34 of the second hydraulic cylinder 30 and the cylinder 24 of the first hydraulic cylinder 20. Supplying to the rod side, the rod 33 of the second hydraulic cylinder 30 is extended, and the rod 23 of the first hydraulic cylinder 20 is reduced. The hydraulic pressure discharged from the rod side of the second hydraulic cylinder 30 and the head side of the first hydraulic cylinder 20 by returning the rod 33 and reducing the rod 23 is returned to the tank 57.

  Since the thrust generated by the supply of the hydraulic pressure is supplied only in the direction in which the bucket 10 is opened (the head side of the second hydraulic cylinder 30 and the rod side of the first hydraulic cylinder 20), the bucket 10 is a force corresponding to the supplied oil pressure. Opened at. Therefore, when the bucket 10 is opened with a large load in the excavation groove, or when the bucket 10 is opened such as when the weight of the stored earth and sand is large, that is, when the gripping force is given priority over the opening / closing speed. The bucket 10 is opened by the normal circuit described above.

  FIG. 16 is an explanatory diagram when the bucket 10 is opened by a differential circuit giving priority to the opening and closing speed. By supplying hydraulic pressure to both the head side and the rod side of the cylinder 34 of the second hydraulic cylinder 30 by the hydraulic pump 56. The rod side hydraulic pressure is pushed against the head side hydraulic pressure due to the area difference of the cylinder 34 and is supplied to the head side. Therefore, the rod 33 is a hydraulic pressure obtained by adding the hydraulic pressure supplied to the rod side to the hydraulic pressure supplied to the head side. The stretching speed increases because of stretching. The hydraulic pressure of the first hydraulic cylinder 20 is returned to the tank 57 and supplied to the rod side because the rod 23 contracts as the rod 33 of the second hydraulic cylinder 30 expands and the rod 23 contracts.

  The thrust of the rod 33 due to the supply of the hydraulic pressure is limited to the same thrust as the diameter of the rod 33 because the same pressure is generated also on the rod side of the second hydraulic cylinder 30. Therefore, when the bucket 10 is opened in a state where the load is small in the excavation groove, or when the load when the bucket 10 is opened to discharge the stored earth and sand is small, that is, no gripping force is required, and the opening / closing speed is given priority. In the case of the operation, the bucket 10 is opened by the differential circuit described above.

  As an example, when the opening and closing speed of the shells 11 and 12 takes 42 seconds in the normal circuit giving priority to the opening and closing force of the bucket 10 shown in FIGS. 13 and 15, the opening and closing speed of the bucket 10 shown in FIGS. When the differential circuit that prioritizes is adopted, the opening and closing speed of the shells 11 and 12 was shortened to 6 seconds. As described above, when the load applied to the bucket 10 is small, it is one of the features of the present invention to employ a differential circuit for both opening and closing the bucket 10 to increase the opening and closing speed. Specifically, by adopting a differential circuit, the bucket 10 can be opened quickly when the excavated earth and sand are discharged, and the cycle time of the earth discharging time can be shortened. Cycle time can be shortened. Note that switching between the normal circuit and the differential circuit is performed on the basis of the pressure set according to the excavation site in the pressure sensor incorporated in the hydraulic manifold of the hydraulic circuit.

  The bucket 10 can turn in the horizontal direction at the current position in a state where the bucket 10 is suspended from the jib 3 of the base machine 2 via the support rope 4. That is, the connection frame 42 of the underground continuous wall excavator 1 is fixed to the turning frame 60, and the turning frame 60 is pivotally supported by the support body 70. This turning mechanism will be described based on the explanatory view of the turning mechanism of the bucket 10 shown in FIGS. In addition, the support body 70 is equipped with a sheave mechanism 77, and the underground continuous wall excavator 1 is suspended by hanging the support rope 4 fed out from the jib 3 around the sheave mechanism 77. In FIGS. 17 and 18, the configuration other than the main part of the turning mechanism is omitted.

  The swivel shaft 71 is fixed to the lower surface of the support body 70 by a bolt 73 via a swivel shaft mounting flange 72 projecting around the swivel shaft 71, hangs down from the support body 70, and is inserted into the swivel frame 60. A turning shaft casing 65 is housed in the turning frame 60, and is fixed to the turning frame 60 on a turning shaft casing mounting flange 66 with bolts 67. A turning shaft 71 inserted into the turning frame 60 is housed in a turning shaft casing mounting flange 66 so as to be turnable through a plurality of bearings 68 in the vicinity of both upper and lower ends.

  The tip of the turning shaft 71 protrudes from the turning shaft casing 65 and is connected to the pinion gear 61. A rack gear 62 meshes with the pinion gear 61, and a rod 64 of a turning hydraulic cylinder 63 is connected to the end of the rack gear 62. In the illustrated example, a round rack gear is used as the rack gear 62. Therefore, the pinion gear 61 can be rotated by advancing and retracting the rack gear 62 in the arrow Y direction by extending and retracting the rod 64 of the turning hydraulic cylinder 63. Therefore, by the advance and retreat of the rack gear 62, the turning shaft 71 connected to the pinion gear 61 can be turned and the turning frame 60 can be turned relative to the support 70.

  Specifically, the rack gear 62 is moved from the state in which the pinion gear 61 is engaged with the center of the rack gear 62 to the state in which the pinion gear 61 is engaged with one end of the rack gear 62 or the other end shown in FIG. By moving forward and backward, the bucket 10 is rotated 90 degrees in each direction, that is, from the state where the pinion gear 61 is engaged with one end of the rack gear 62 to the state where it is engaged with the other end (see FIG. 17). By advancing and retreating, the bucket 10 can be rotated 180 degrees.

  As long as the bucket 10 can be suspended above the excavation groove by the turning mechanism of the bucket 10, the bucket can be easily positioned without being limited to the position of the base machine 2.

  FIG. 25 is an overall layout diagram of the excavation site, and shows a state in which excavation grooves are excavated in the excavation area 5 using the underground continuous wall excavators 1a, 1b, and 1c. The base machine 2a installs the jib 3a in a direction orthogonal to the excavation area 5, and performs excavation by matching the opening / closing direction of the bucket 10a of the underground continuous wall excavator 1a with the width direction of the excavation area 5. . This position is the basic posture for excavation work. However, in the operation of excavating the corner portion of the excavation area 5 like the base machine 2b, the jib 3b cannot be positioned in the basic posture. Similarly, in the base machine 2c, the jib 3c cannot be positioned in the basic posture due to the presence of the base machine 2d (obstacle). Therefore, the open / close direction and the width direction of the excavation area 5 do not coincide with the buckets 10b and 10c of the underground continuous wall excavators 1b and 1c suspended from the jibs 3b and 3c.

  Therefore, by turning the buckets 10b, 10c of the underground continuous wall excavators 1b, 1c suspended on the jibs 3b, 3c in the horizontal direction at the current position by the turning mechanism, the buckets 10b, 10b, By matching the opening / closing direction of 10c and the width direction of the excavation area 5, excavation can be performed in the same manner as when the jibs 3b and 3c are positioned in the basic posture.

  In the present invention, a hydraulic unit that supplies hydraulic pressure as a driving source to the first hydraulic cylinder 20 and the second hydraulic cylinder 30 is separated from the underground continuous wall excavator 1 and installed on the ground, and the hydraulic hose 7a is used for hydraulic control. A plurality of tube bodies 7 including a cabtyre cable 7b and a communication cable 7c for supplying necessary power such as a power source for solenoid valves and a power source for inclinometers are respectively connected to reels 6a, 6b, 6c of the base machine 2. The reel 6 (see FIG. 4) is wound so that it can be unwound and wound up, and is extended from the ground via the jib 3 to the underground continuous wall excavator 1 in the excavation groove and supplied with hydraulic pressure and power to be controlled. ing.

  In the present invention, the depth of about 30 m to 60 m, which has been the main body so far, is larger, more specifically, the depth reaches more than 60 m and reaches 100 m, and further has a depth of 100 m or more. Since the drilling of deep excavation grooves is also targeted, in the current situation where the maximum length of the provided hydraulic hose 7a is about 65 m, it is necessary to connect a plurality of hydraulic hoses 7a, and this connecting portion is 150 mm. It is inevitable that it becomes a straight line of a degree. Further, the pipes 7 such as the hydraulic hose 7a, the cabtyre cable 7b, and the communication cable 7c are subjected to a sudden load due to the operation of the underground continuous wall excavator 1, the time lag of the feeding and winding operation of the pipe 7, and the like. The deeper the excavation groove, the higher the risk and the greater the load.

  Therefore, in the present invention, the pipe body 7 such as the hydraulic hose 7a having a linear connecting portion is abruptly loaded on the pipe body 7 together with the guide mechanism 80 for smoothly unwinding and winding the pipe body 7 through the jib 3. The shock absorber 90 for absorbing and relaxing the load on the tube 7 in the jib 3 so that the tube 7 such as the hydraulic hose 7a, the cabtyre cable 7b, the communication cable 7c and the like is not damaged even if it is applied. Equipped with.

  FIGS. 19 and 20 are explanatory views of the structure of the tip of the jib 3 in the base machine 2. A tip frame 81 is attached to the tip of the jib 3, and the underground continuous wall excavator 1 is suspended from the tip frame 81. A tip sheave 82 for supporting the support rope 4 such as a wire for supporting is pivotally supported rotatably, and the support rope 4 is fed out and taken up via the tip sheave 82. 83 is an auxiliary sheave supported on the tip frame 81 in the same manner.

  At the open end portion of the front end frame 81, a guide mechanism 84 for supporting the pipe body 7 such as the hydraulic hose 7a and the like so as to smoothly feed and wind the guide frame 84, and a guide frame 84 bent in an arc shape, A plurality of guide rollers 85 that are rotatably provided are provided. In the illustrated example, the curvature of the guide frame 84 is R = 1000, and a plurality of guide rollers 85 are arranged in close contact with the entire area of the guide frame 84 so as to be capable of rotating. Since the curvature of the linear connecting portion of the hydraulic hose 7a is about R = 350, the tubular body 7 such as the hydraulic hose 7a is supported in a gentle arc shape by the guide mechanism 80 having the above-described configuration, and the underground continuous wall excavator Up to 1, it is smoothly stretched including the connection for connection.

  One end of the guide frame 84 is fixed to a base frame 86 extending laterally from the tip frame 81 of the jib 3 by a fixed shaft 87 and the other end is opened without being fixed to other members. ing. Further, the guide mechanism 80 is equipped with a buffering device 90 including a buffering hydraulic cylinder 91 for absorbing and relaxing the load on the tube body 7 and an accumulator 92 for storing hydraulic pressure from the buffering hydraulic cylinder 91. It is. That is, the rod side end of the buffer hydraulic cylinder 91 is fixed to the center of the lower surface of the arcuate guide frame 84, the head side end is fixed to the base frame 86, and the accumulator 92 is fixed to the base frame 86. Yes. The accumulator 92 is divided into two chambers by a prada 94, which is a rubber diaphragm. One of the accumulators 92 is connected to a buffering hydraulic cylinder 91 and can store hydraulic pressure from the buffering hydraulic cylinder 91. Is filled with high-pressure gas.

  As shown in FIG. 19, the rod 93 of the buffering hydraulic cylinder 91 is in an extended state as a result of the balance between the hydraulic pressure of the accumulator 92 and the high-pressure gas, as shown in FIG. When a certain load or more is generated on the tube body 7 due to an impact caused by the operation of the underground continuous wall excavator 1, as shown in FIG. 21, the rod 93 is contracted by the load, and the hydraulic pressure in the buffering hydraulic cylinder 91 is increased. The oil is allowed to flow into 92, and the high pressure gas contracts and absorbs the hydraulic pressure to relieve the load.

  When the load disappears, as shown in FIG. 22, the hydraulic pressure in the accumulator 92 is discharged to the buffering hydraulic cylinder 91 by the expansion of the high-pressure gas, and the rod 93 of the buffering hydraulic cylinder 91 is extended to become normal. Return.

  In the present invention, since the underground continuous wall excavator 1 is suspended from the jib 3 via the support rope 4, the excavation groove bends during excavation due to differences in soil components in the excavation direction, obstacles, and the like. The danger is inherent. Therefore, a means for correcting the attitude of the underground continuous wall excavator 1 in accordance with the excavation groove may be required so that the excavation groove can be prevented from being bent in the vertical direction. Therefore, the underground continuous wall excavator 1 is equipped with the posture correcting device 100 shown in FIG.

  As shown in FIGS. 23 and 24, this posture correcting device 100 fixes the head side end portion of the posture correcting hydraulic cylinder 102 in the posture correcting box 101 formed of a rectangular parallelepiped block, and corrects the posture of the rod 103. The box 101 can extend and contract outside. The rod 103 is attached to a rectangular posture correcting plate 104 having a predetermined area by a rotating shaft 105 so as to be rotatable. In addition, a pair of free rods 106 that are pivotally supported in the posture correction box 101 so as to extend and contract are fixed to the posture correction plate 104 with the rod 103 interposed therebetween.

  Therefore, by operating the posture correcting hydraulic cylinder 102 and extending the rod 103, the posture correcting plate 104 and the free rod 106 are extended as shown in FIG. Further, the posture correcting plate 104 can be rotated about the rotation shaft 105. Therefore, when it becomes necessary to correct the posture of the underground continuous wall excavator 1, the ground in the excavation groove is pressed by expanding and contracting the posture correction plate 104 at the required location in the excavation groove and pressing the groove wall. The position of the medium continuous wall excavator 1 can be corrected and held at the optimum position. In the illustrated example, the posture correcting device 100 is installed on both side surfaces (the opening and closing direction of the bucket 10) of the upper end portion of the connection frame 42 and the lower end portion of the main body frame 40, but the opening and closing direction of the bucket 10 is shown. The posture correcting device 100 is also provided in the connecting frame 42 and the main body frame 40 in a direction perpendicular to the main body frame 40. Furthermore, the installation location of the posture correction box 101 may be an arbitrary location.

  A construction method for excavating a trench for constructing an underground continuous wall using the underground continuous wall excavator 1 is as follows. The underground continuous wall excavator 1 is suspended from the base machine 2 via a support rope 4 made of a wire, and the first hydraulic cylinder 20 and the second hydraulic pressure are operated to open and close the bucket 10 consisting of a pair of left and right shells 11 and 12. By alternately extending and contracting the cylinder 30, a predetermined depth for constructing the underground continuous wall, for example, a depth that reaches 60m over 60m, and a depth of 100m or more The excavation groove is excavated while filling the excavation groove with a stabilizing liquid and preventing the excavation groove wall from collapsing. Then, due to the load applied to the bucket 10, the rod 23 of the first hydraulic cylinder 20 and the rod 33 of the second hydraulic cylinder 30 are extended using a differential circuit with priority given to the opening / closing speed when the load is low. On the other hand, when the load is high, the opening / closing operation of the bucket 10 is performed using a normal circuit with priority given to the opening / closing force. That is, the excavation groove is excavated by controlling the opening / closing force and opening / closing speed of the bucket 10.

  Then, the bucket 10 is turned relative to the support 70 by turning the turning shaft 71 by driving the turning hydraulic cylinder 63 to slide the rack gear 62 and rotating the pinion gear 61. Thus, the position of the bucket 10 with respect to the excavation groove is adjusted without moving the base machine 2 with respect to the excavation groove.

  When excavating, the hydraulic hose 7a supported by the guide mechanism 80 is connected to the underground continuous wall excavator 1 from a hydraulic unit installed on the ground to supply hydraulic pressure to open and close the bucket 10, and the ground. The cabtire cable 7b supported by the guide mechanism is connected to the underground continuous wall excavator 1 from the power supply unit installed in the underground.

  According to the present invention described above, since the underground continuous wall excavator is suspended from the jib of the base machine by the support rope such as a wire, the length of the support rope can be wound around the winch drum of the base machine. Since there is no restriction on the feed amount, the depth that exceeds the depth of about 30 m to 60 m, which has been the main body so far, more specifically, the depth that exceeds 60 m and reaches 100 m, and further, the depth of 100 m or more It is possible to excavate a deep trench such as

  The first hydraulic cylinder and the second hydraulic cylinder that open and close the bucket are arranged on the center line of the bucket and are provided at the center of the underground continuous wall excavator. Less risk. In addition, since the first hydraulic cylinder arranged in the upper stage and the second hydraulic cylinder arranged in the lower stage are arranged in series in the vertical direction with the rod side ends facing each other, the first hydraulic cylinder extends and the first hydraulic cylinder extends. When the two hydraulic cylinders are reduced, the bucket is closed, the first hydraulic cylinder is reduced, and when the second hydraulic cylinder is extended, the bucket is opened, so that the bucket can be opened and closed with the same thrust. In addition, since the shell opening and closing operations are performed in conjunction with the left and right in both the first hydraulic cylinder and the second hydraulic cylinder, the matching opening and closing operations are performed.

  Furthermore, the rod of the first hydraulic cylinder extends during the closing operation of the bucket, and the rod of the second hydraulic cylinder extends during the opening operation of the bucket. Therefore, the hydraulic pressure for extending the rods of the first hydraulic cylinder and the rods of the second hydraulic cylinder is set according to the excavation situation, that is, according to the degree of load applied to the bucket. The supply of hydraulic pressure by the differential circuit can be selected. That is, if the bucket is opened in a state where the load is small in the excavation groove, or if the bucket is opened to discharge the stored earth and sand, that is, when gripping force is not required and the opening and closing speed is given priority, differential Select the circuit and open the bucket. Similarly, when excavating soft ground with low excavation resistance, grabbing earth and sand with low excavation resistance, or closing an open bucket without grabbing earth and sand, that is, no gripping force is required, opening and closing speed is given priority. If so, select the differential circuit and close the bucket.

  In addition, when the base machine cannot be positioned with respect to the excavation groove, the swing frame equipped with the bucket is pivotally supported on the support so that the bucket can be swung horizontally at the current position. As long as the bucket can be suspended in the sky above the excavation groove by rotating the bucket in the horizontal direction at the current position, the bucket can be easily positioned without being restricted by the position of the base machine. . This turning mechanism has a structure in which a pinion gear is connected to the turning shaft, the rack gear is engaged with the pinion gear, and the rack gear is advanced and retracted by a turning hydraulic cylinder, so that the turning mechanism can be turned to an accurate position steplessly. .

  In the jib of the base machine that suspends and supports this underground continuous wall excavator with a support rope, a buffer hydraulic cylinder is installed in the guide mechanism that supports the tubular body such as a hydraulic hose and cab tire cable connected to the underground continuous wall excavator. And an accumulator that stores the hydraulic pressure from the buffer hydraulic cylinder, and equipped with a shock absorber to absorb and relieve the load on the pipe body. Even when a sudden load is applied due to a time lag or the like, the load can be absorbed and buffered.

  In addition, the open end of the jib tip frame supports a tubular body such as a hydraulic hose, and can be rotated into a guide frame that is curved in an arc as a guide mechanism for smoothly feeding and winding, and a guide frame Because it is equipped with a plurality of guide rollers equipped in, the pipe body such as a hydraulic hose is supported in a gentle arc shape by the guide mechanism, and it is smoothly extended and guided to the underground continuous wall excavator including the connecting part. Can do.

1, 1a, 1b, 1c ... underground continuous wall excavator 2, 2a, 2b, 2c ... base machine 2d ... base machine (obstacle)
3, 3a, 3b, 3c ... Jib 4 ... Supporting rope 5 ... Excavation zone 6, 6a, 6b, 6c ... Reel 7 ... Tube 7a ... Hydraulic hose 7b ... Cab tire cable 7c ... Communication cable 10, 10a, 10b, 10c ... Bucket 11, 12 ... Shell 13, 14 ... Tie rod 15, 16 ... Connecting pin 20 ... First hydraulic cylinder 21 ... Rod side end 22 ... Head side end 23, 33, 64, 93, 103 ... Rod 24 ... Cylinder 25, 26, 35, 36 ... fixed pin 30 ... second hydraulic cylinder 31 ... rod side end 32 ... head side end 34 ... cylinder 40 ... main body frame 41 ... shell mounting frame 42 ... connection frame 40a, 41a, 42a ... Window part 44 ... Sliding plate 45a, 45b, 45c ... Flange 46a, 46b, 46c ... Rib 47, 48, 49 ... Pin hole 50 ... Slide Box 51 ... Sliding plate 52, 53, 54, 55 ... Pin hole 56 ... Hydraulic pump 57 ... Tank 60 ... Swivel frame 61 ... Pinion gear 62 ... Rack gear 63 ... Swivel hydraulic cylinder 65 ... Swivel shaft casing 66 ... Swivel shaft casing Mounting flange 67, 73 ... Bolt 68 ... Bearing 70 ... Supporting body 71 ... Turning shaft 72 ... Turning shaft mounting flange 77 ... Sheave mechanism 80 ... Guide mechanism 81 ... Tip frame 82 ... Tip sheave 83 ... Auxiliary sheave 84 ... Guide frame 85 ... Guide roller 86 ... Base frame 87 ... Fixed shaft 90 ... Shock absorber 91 ... Buffer hydraulic cylinder 92 ... Accumulator 94 ... Prada 100 ... Posture correction device 101 ... Posture correction box 102 ... Posture correction hydraulic cylinder 104 ... Posture correction plate 105 ... Rotating shaft 106 ... Free rod

Claims (6)

In the jib that supports the underground continuous wall excavator that excavates the excavation groove by opening and closing the bucket consisting of a pair of left and right shells by a hydraulic cylinder,
A guide mechanism comprising an arcuate guide frame whose one end is fixed to the base frame erected on the tip frame of the jib and whose other end is opened, and a plurality of guide rollers which are rotatably mounted along the arc of the guide frame. Equipped with
The rod side end is fixed to the center of the bottom surface of the arc-shaped guide frame, the head side end is fixed to the base frame, and the buffer hydraulic cylinder is fixed to the base frame and stores hydraulic pressure from the buffer hydraulic cylinder. Equipped with a shock absorber consisting of an accumulator,
By supporting the pipe connected to the underground continuous wall excavator with a guide mechanism ,
Normally, the rod of the buffer hydraulic cylinder is in an extended state, and when a load exceeding a certain level is generated in the tube body, the rod is contracted by the load and the hydraulic pressure in the buffer hydraulic cylinder flows into the accumulator. While absorbing the load on the body with a shock absorber ,
A jib for suspending an underground continuous wall excavator characterized in that when a load above a certain level disappears, the rod is extended by supplying the hydraulic pressure in the accumulator to the buffering hydraulic cylinder with high-pressure gas . Jib a load, to Tsu支the diaphragm wall excavator a shock occurring in the tube is claim 1 Symbol placing by the operation of the diaphragm wall excavator. Jib tubular body, to Tsu支the diaphragm wall excavator according to claim 1 or 2, wherein a hydraulic hose for supplying hydraulic pressure to the diaphragm wall excavator. Jib tubular body, to Tsu支the diaphragm wall excavator according to claim 1 or 2, wherein a flexible cable for supplying the power while the earth continuous wall excavator. Tubular body, according to claim 1 or 2 underground continuous wall, wherein the flexible cable for supplying power to the hydraulic hose及beauty locations in the continuous wall excavator for supplying hydraulic pressure to the diaphragm wall excavator A jib that hangs an excavator. An underground continuous wall excavator for excavating a excavation groove by opening and closing a bucket consisting of a pair of left and right shells by a hydraulic cylinder to a jib that suspends the underground continuous wall excavator according to claim 5 via a support rope. The hydraulic hose supported by the guide mechanism from the hydraulic unit installed on the ground is connected to the underground continuous wall excavator to supply hydraulic pressure to open and close the bucket, and the power supply installed on the ground By connecting the cabtire cable supported by the guide mechanism from the unit to the underground continuous wall excavator, by supplying power to the underground continuous wall excavator, a predetermined depth for constructing the underground continuous wall In the underground continuous wall excavation method to excavate while filling the excavation groove of the stable groove into the excavation groove to prevent the excavation groove wall from collapsing ,
An underground continuous wall excavation method characterized by absorbing the load on the hydraulic hose and cabtyre cable with a shock absorber to reduce the load .

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