Casing rotary press-fitting device

Abstract

To provide a casing rotary press-fitting device that can suppress the rotation of the reaction force beam and improve work efficiency. [Solution] The casing rotary press-fitting device 1 includes a base plate 2, a base frame 4, a lifting frame 5, a lifting cylinder 8, a hydraulic motor 10, a hydraulic unit U controlled by a controller, and a reaction beam 20 whose base end 21 is connected to the base frame 4. The hydraulic unit U supplies hydraulic pressure corresponding to a set rotational torque to the hydraulic motor 10 and hydraulic pressure corresponding to a set pressing force to the lifting cylinder 8. The tip 22 of the reaction beam 20 includes a crawler engagement portion KK into which the crawler 210 of a crawler crane 200 mounted on the ground engages. An acquisition means acquires information related to the rotation start behavior of the reaction beam 20 about the central axis C1 of the casing 100. The controller is configured to suppress the rotation of the reaction beam 20 based on the information acquired by the acquisition means.

Description

Technical Field

[0001] The present invention relates to a casing rotary press-fitting device.

Background Art

[0002] A tubing device (casing rotary press-fitting device) that excavates a pile hole by pushing a casing tube into the ground while rotating receives a rotational reaction force. In Patent Document 1, a rotational reaction force receiving device has been proposed in which a tubing device and a crawler crane as a rotational reaction force receiver are connected by a connecting member, and a connecting member at one end of the connecting member sandwiches the crawler on both sides.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] At a construction site, a crawler crane suspends a hammer grab that can be inserted into the casing, and the hammer grab serves to carry out the remaining soil in the casing. If a crawler crane having such a role is displaced due to a rotational reaction force, it is necessary to return the crawler crane to its normal position, which affects the work efficiency.

[0005] One embodiment of the present invention provides a casing rotary press-fitting device that can suppress the generation of rotation of a reaction beam and has high work efficiency.

Means for Solving the Problems

[0006] One embodiment of the present invention provides a casing rotary press-fitting device (1) for rotary press-fitting a casing (100) into the ground (300). The casing rotary press-fitting device includes a base plate (2) placed on the ground, a base frame (4) supported on the base plate via a jack (3), a lifting frame (5) supported on the base frame so as to be able to move up and down, a chuck mechanism (7) capable of gripping the casing, a hydraulic motor (10) that applies rotational torque to the casing via the chuck mechanism, a hydraulic cylinder (8) that supports the lifting frame so as to be able to move up and down relative to the base frame and applies a pressing force (F) to the casing into the ground via the lifting frame and the chuck mechanism, and a hydraulic pressure corresponding to a set rotational torque (TS). The system includes a hydraulic unit (U) that supplies hydraulic pressure to the hydraulic cylinder corresponding to a set pressing force (FS) to the hydraulic motor, a controller (60) that controls the hydraulic unit, a reaction beam (20) that supports the rotational reaction force during excavation, and a tip (22) having a crawler engagement portion (KK) into which the crawler (210) of a crawler crane (200) placed on the ground engages, with the tip (21) connected to the base frame and the tip (22) engaging with the crawler (210) of the crawler crane (200) placed on the ground, and an acquisition means (31, 31A, 31B; 32A, 32B; 33) that acquires information relating to the rotation start behavior of the reaction beam about the central axis (C1) of the casing. The controller is configured to suppress the rotation of the reaction beam based on the information acquired by the acquisition means.

[0007] This configuration suppresses the rotation of the reaction beam based on information related to the rotation initiation behavior of the reaction beam, thereby preventing the crawler crane from shifting position during excavation. As a result, it becomes unnecessary to interrupt excavation work to return the crawler crane to its correct position, thus increasing work efficiency.

[0008] The alphanumeric characters in parentheses represent the corresponding components in the embodiments described later, but this does not mean that the present invention should be limited to those embodiments. The same applies hereafter in this section.

[0009] In one embodiment, the controller includes a determination unit (61, 62, 63) that determines whether or not the reaction beam has started rotating based on the information acquired by the acquisition means, and a reaction beam rotation suppression unit (64) that suppresses the rotation of the reaction beam by reducing the set rotation torque when the determination unit determines that the rotation has started. With this configuration, when the reaction beam has started rotating, the rotation of the reaction beam can be suppressed by reducing the rotation torque applied to the casing and thereby reducing the rotational reaction force.

[0010] In one embodiment, the acquisition means includes a pressure sensor (31; 31A, 31B) positioned on the crawler engagement portion for detecting the pressure (P) generated at the contact portion between the crawler engagement portion and the crawler, and the determination unit includes a pressure reference determination unit (61) that determines whether or not the rotation start behavior occurs based on the change in pressure detected by the pressure sensor.

[0011] With this configuration, in contrast to the current situation where reaction beams of various specifications are used at each site, the presence or absence of rotational initiation behavior can be reliably detected based on the change in pressing force detected by the pressing force sensor located at the crawler engagement part, regardless of the specifications of the reaction beam.

[0012] In one embodiment, the pressing force reference determination unit is configured to detect a reversal from an increase in pressing force to a decrease in pressing force based on the pressing force detected by the pressing force sensor (step S81), detect the pressing force decrease rate (RP) during a predetermined elapsed time from the reversal (step S82), and determine that the rotation start behavior has occurred when the detected pressing force decrease rate is greater than or equal to a predetermined decrease rate (Rk) (step S83). The behavior when the reaction force beam starts to rotate is thought to be that after a reversal from an increase in pressing force to a decrease in pressing force occurs, the pressing force drops sharply. Therefore, the unit is configured to determine that the reaction force beam has started to rotate when such a phenomenon occurs.

[0013] In one embodiment, the crawler engagement portion includes a U-shaped engagement groove (24) in plan view, into which the front end of the crawler is fitted, and the pair of inner surfaces (24a) of the engagement groove are parallel to the longitudinal direction (L) of the reaction beam. The pressing force sensor is positioned on at least the inner surface of the pair of inner surfaces (24a) of the engagement groove in the direction of rotation (R1) of the casing. With this configuration, by positioning the pressing force sensor on at least the inner surface on the side that receives the rotational reaction force in the U-shaped engagement groove, it is possible to detect whether or not the reaction beam is beginning to rotate.

[0014] In one embodiment, the crawler engagement portion includes a triangular or trapezoidal engagement groove (25) in plan view, into which the front end of the crawler is fitted, and which has a pair of inner surfaces (25a) inclined in opposite directions with respect to the longitudinal direction of the reaction beam. The pressure sensor includes a pair of pressure sensors (31A, 31B) respectively arranged on the pair of inner surfaces of the engagement groove. With this configuration, the pressure can be detected at two locations on both sides of the front end of the crawler by the pair of pressure sensors arranged on the pair of inner surfaces of the triangular or trapezoidal engagement groove in plan view.

[0015] In one embodiment, the pressure reference determination unit is configured to determine whether or not the rotation start behavior occurs based on the sum (Pa + Pb) of the pressing forces (Pa, Pb) detected by the pair of pressing force sensors. This configuration improves the accuracy of detecting whether or not the reaction force beam is rotating.

[0016] In one embodiment, the acquisition means further includes strain sensors (32A, 32B) for detecting the amount of strain (ε) generated in the connecting mechanism (V) that connects the base end of the reaction beam to the base frame, and the determination unit further includes a strain amount reference determination unit (62) for determining whether or not the rotation start behavior occurs based on the change in the amount of strain detected by the strain sensors. With this configuration, the presence or absence of rotation start behavior of the reaction beam is detected not only using the pressing force detected by the pressing force sensor but also using the amount of strain detected by the strain sensors. Therefore, the detection accuracy of the presence or absence of rotation start behavior of the reaction beam can be improved.

[0017] In one embodiment, the strain amount reference determination unit is configured to detect a reversal from strain amount increase to strain amount decrease based on the strain amount detected by the strain sensor (step S84), detect the strain amount decrease rate (Rε) during a predetermined elapsed time from the reversal (step S85), and determine that the rotation start behavior has occurred when the detected strain amount decrease rate is equal to or greater than a predetermined decrease rate (Rh) (step S86). As for the behavior when the reaction force beam starts to rotate, it is thought that after a reversal from strain amount increase to strain amount decrease occurs, the strain amount drops sharply. By determining that the reaction force beam has started to rotate when such a phenomenon occurs, the presence or absence of the reaction force beam starting to rotate can be detected well.

[0018] In one embodiment, the acquisition means further includes an acceleration sensor (33) that detects acceleration in the radial direction about the central axis of the casing, and the determination unit includes an acceleration reference determination unit (63) that determines whether or not the rotation start behavior occurs based on the acceleration detected by the acceleration sensor. With this configuration, the presence or absence of rotation start behavior of the reaction beam is detected not only using the pressure detected by the pressure sensor and the amount of strain detected by the strain sensor, but also using the acceleration detected by the acceleration sensor. Therefore, the detection accuracy of the presence or absence of rotation start behavior of the reaction beam can be improved.

[0019] In one embodiment, the acquisition means includes at least one of a pressing force sensor disposed at the crawler engaging portion for detecting a pressing force generated at the contact portion between the crawler engaging portion and the crawler, a strain sensor for detecting a strain amount generated in the reaction force beam, and an acceleration sensor for detecting a radial acceleration centered on the central axis of the casing. According to this configuration, the presence or absence of the rotation start behavior can be detected using at least one of the pressing force sensor, the strain sensor, and the acceleration sensor.

[0020] In one embodiment, it further includes a lifting state detection sensor for detecting a predetermined lifting state of the base frame from the base plate. The controller is configured to reduce the set pressing force in response to the detection of the predetermined lifting state by the lifting state detection sensor. According to this configuration, the lifting of the base frame can be suppressed. Therefore, the frictional force between the base plate loaded with the weight of the casing rotary press-fitting device and the ground surface can be effectively used to resist the rotational reaction force, and thus the rotation of the reaction force beam can be effectively suppressed.

[0021] In one embodiment, the lifting state detection sensor includes a limit switch (34) that turns on when the base frame lifts a predetermined amount from the base plate. According to this configuration, the lifting state of the base frame can be detected with a simple configuration.

Brief Description of the Drawings

[0022] [Figure 1] FIG. 1 is a schematic front view of a casing rotary press-fitting device according to an embodiment of the present invention. [[ID=X]] [Figure 2] FIG. 2 is a schematic side view of the casing rotary press-fitting device and the crawler crane. [Figure 3] FIG. 3 is a schematic plan view of the casing rotary press-fitting device and the crawler crane. [Figure 4] FIG. 4 is a partially broken plan view of the reaction force beam. [Figure 5]FIG. 5 is a block diagram mainly showing an electrical configuration for controlling a hydraulic unit. [Figure 6] FIG. 6 is a block diagram showing an output circuit of a pair of strain sensors. [Figure 7] FIG. 7 is a flowchart showing the flow of processing of a controller. [Figure 8] FIG. 8 is a flowchart showing the flow of rotation start behavior detection processing. [Figures 9A-9C] FIG. 9A is a graph showing the temporal change of the pressing force detected by a pressing force sensor. FIG. 9B is a graph showing the temporal change of the amount of strain detected by a strain sensor. FIG. 9C is a graph showing the temporal change of the acceleration detected by an acceleration sensor. [Figure 10] FIG. 10 is a schematic plan view of a reaction force beam in another embodiment of the present invention. [Figure 11] FIG. 11 is a block diagram showing an output circuit of a pair of pressing sensors in another embodiment of the present invention. MODE FOR CARRYING OUT THE INVENTION

[0023] Hereinafter, embodiments embodying the present invention will be described with reference to the drawings.

[0024] FIG. 1 is a schematic front view of a casing rotary press-fitting device 1 according to an embodiment of the present invention. As shown in FIG. 1, the casing rotary press-fitting device 1 includes a base plate 2, four jacks 3, a base frame 4, a lifting frame 5, a chuck frame 6, a chuck mechanism 7, four lifting cylinders 8 (hydraulic cylinders), four chuck cylinders 9, and four hydraulic motors 10. In FIG. 1, only two of the jacks 3, the lifting cylinders 8, the chuck cylinders 9, and the hydraulic motors 10 are shown.

[0025] The base plate 2 is a rectangular plate placed on the ground 300. The base frame 4 is supported via four jacks 3 located at the four corners of the base plate 2. The four jacks 3 function to adjust the level of the base frame 4. The jacks 3 are connected to the base frame 4. Therefore, if the base frame 4 lifts up, the jacks 3 will lift up from the base plate 2. To address this, the base plate 2 is provided with guides 2a of a predetermined height that surround at least a portion of each jack 3. This restricts the base frame 4 from rotating around the central axis C1 of the casing 100 via the base plate 2.

[0026] The lifting frame 5 is supported on the base frame 4 so as to be able to move up and down via four lifting cylinders 8. The chuck frame 6 is supported on the lifting frame 5 so as to be able to move up and down via four chuck cylinders 9. The base plate 2, base frame 4, lifting frame 5, and chuck frame 6 have through holes with a circular cross-section through which the casing 100 is inserted.

[0027] Figure 2 is a schematic side view of the casing rotary press-fitting device 1 and the crawler crane 200. As shown in Figure 2, the casing rotary press-fitting device 1 includes a reduction gear 11, a hydraulic pump 12, an oil tank 13, a hydraulic unit U, a reaction beam 20, a pressing force sensor 31, strain sensors 32A and 32B, an acceleration sensor 33, a limit switch 34, and a controller 60.

[0028] The acceleration sensor 33 detects acceleration in the radial direction around the central axis C1 of the casing 100. The acceleration sensor 33 is attached to each of the cylinder bodies 8a of the four lifting cylinders 8, for example. The acceleration sensor 33 may also be a gyro sensor.

[0029] The limit switch 34 provides a lift state detection sensor that detects a predetermined lift state of the base frame 4 from the base plate 2. The controller 60 is configured to reduce the pushing force F by adjusting the cylinder hydraulic pressure of the lifting cylinder 8 in response to the detection of a predetermined lift state of the base frame 4 when the limit switch 34 is turned on.

[0030] The chuck mechanism 7 includes a rotating frame 71 having a tapered hole 71a, a plurality of wedge members 72, a plurality of link mechanisms 73, and a support ring 74. The rotating frame 71 is rotatably supported on the lifting frame 5 via bearings 14. The support ring 74 is rotatably supported on the chuck frame 6 via bearings 15. The plurality of wedge members 72 are rotatably connected to the support ring 74 via corresponding link mechanisms 73.

[0031] By shortening the chuck cylinder 9, multiple wedge members 72 are inserted between the outer circumference of the casing 100 and the inner surface of the tapered hole 71a. As a result, the chuck mechanism 7 grips the casing 100, and the casing 100 and the rotating frame 71 are fastened together so that they can rotate as a single unit.

[0032] The hydraulic motor 10 is positioned on the lifting frame 5. The hydraulic motor 10 rotates the rotating frame 71 (chuck mechanism 7) via the reduction gear 11, thereby applying rotational torque to the casing 100 gripped by the chuck mechanism 7 via the reduction gear 11 and the chuck mechanism 7. The reduction gear 11 amplifies the rotational torque of the hydraulic motor 10 and transmits it to the chuck mechanism 7 and the casing 100.

[0033] By shortening, the lifting cylinder 8 lowers the lifting frame 5, applying a pressing force F to the casing 100, which is gripped by the chuck mechanism 7, through the lifting frame 5 and the chuck mechanism 7, into the ground 300. By rotating the casing 100 with the hydraulic motor 10 and lowering the casing 100 with the lifting cylinder 8, the casing 100 is rotated and pressed into the ground 300.

[0034] The hydraulic unit U includes a first hydraulic circuit 40 that supplies hydraulic pressure corresponding to a set rotational torque TS to the hydraulic motor 10, and a second hydraulic circuit 50 that supplies hydraulic pressure corresponding to a set pushing force FS to the lifting cylinder 8. The controller 60 controls the hydraulic unit U. The controller 60 pushes in and pulls out the casing 100 by rotating the chuck mechanism 7 that grips the casing 100 with the hydraulic motor 10, and raising and lowering the chuck mechanism 7 that grips the casing 100 with the lifting cylinder 8.

[0035] The first hydraulic circuit 40 includes an electromagnetic switching valve 41, a supply oil passage 42 connecting the hydraulic pump 12 and the switching valve 41, a return oil passage 43 connecting the oil tank 13 and the switching valve 41, a relief oil passage 44 connecting the supply oil passage 42 and the return oil passage 43, an electromagnetic relief valve 45 located in the relief oil passage 44, and a pressure sensor 46 located in the supply oil passage 42.

[0036] The switching valve 41 controls the rotation direction of the hydraulic motor 10 by controlling the flow of pressurized oil supplied from the hydraulic pump 12, which is driven by the engine E, to the hydraulic motor 10. The electromagnetic relief valve 45 is set to a relief set value RS1 corresponding to the set rotational torque TS. The hydraulic motor 10 is supplied with motor hydraulic pressure corresponding to the relief set value RS1 of the relief valve 45.

[0037] The second hydraulic circuit 50 includes an electromagnetic switching valve 41, a supply oil passage 52 connecting the hydraulic pump 12 and the switching valve 51, a return oil passage 53 connecting the oil tank 13 and the switching valve 51, a relief oil passage 54 connecting the supply oil passage 52 and the return oil passage 53, an electromagnetic relief valve 55 located in the relief oil passage 54, and a pressure sensor 56 located in the supply oil passage 52.

[0038] The lifting cylinder 8 is an inverted hydraulic cylinder including a cylinder body 8a, a rod 8b, a piston 8c, a first oil chamber 81, and a second oil chamber 82. The cylinder body 8a is fixed to the lifting frame 5. The upper end of the rod 8b is fixed to the piston 8c. The lower end of the rod 8b protrudes downward from the cylinder body 8a and is fixed to the base frame 4. The piston 8c partitions the upper first oil chamber 81 and the lower second oil chamber 82 within the inverted cylinder body 8a.

[0039] The weight applied to the lifting cylinder 8 corresponds to the total weight Wa of the casing 100, the lifting frame 5, the chuck frame 6, the chuck mechanism 7, and the chuck cylinder 9. In the first case where a pushing force F (F < Wa) smaller than the total weight Wa of the casing 100, the lifting frame 5, the chuck frame 6, the chuck mechanism 7, and the chuck cylinder 9 is obtained, the operating position of the switching valve 51 is switched so as to supply pressure oil from the hydraulic pump 12 to the upper first oil chamber 81. The lifting cylinder 8 supplied with pressure oil to the upper first oil chamber 81 obtains an upward hydraulic pressure GU corresponding to the relief set value RS2 of the relief valve 55. Therefore, the pushing force F becomes a value obtained by subtracting the upward hydraulic pressure GU from the total weight Wa as shown in the following formula (1).

[0040] F = Wa - GU ···(1) In the first case, when reducing the pushing force F, in order to increase the upward hydraulic pressure GU, the relief set value RS2 of the relief valve 55 is increased by a predetermined ratio or a predetermined value.

[0041] On the other hand, in the second case where a pushing force F larger than the total weight Wa of the casing 100, the lifting frame 5, the chuck frame 6, the chuck mechanism 7, and the chuck cylinder 9 is obtained, the operating position of the switching valve 51 is switched so as to supply pressure oil from the hydraulic pump 12 to the lower second oil chamber 82. The lifting cylinder 8 supplied with pressure oil to the lower second oil chamber 82 obtains a downward hydraulic pressure GL corresponding to the relief set value RS2 of the relief valve 55. Therefore, the pushing force F becomes a value obtained by adding the downward hydraulic pressure GL to the total weight Wa as shown in the following formula (2).

[0042] F = Wa + GL ... (2) In the second case, when the pushing force F is reduced, the relief set value RS2 of the relief valve 55 is reduced by a predetermined percentage or a predetermined value in order to increase the downward oil pressure GL.

[0043] Next, the reaction beam 20 will be described. Figure 3 is a schematic plan view of the casing rotary press-fitting device 1 and the crawler crane 200. Figure 4 is a partially broken plan view of the reaction beam 20.

[0044] As shown in Figures 3 and 4, the reaction beam 20 includes a base end 21, a tip end 22, a pair of mounting portions 23 provided on the base end 21, and an engagement groove 24 provided on the tip end 22 as a crawler engagement portion. The base end 21 of the reaction beam 20 is connected to the base frame 4 via a connecting mechanism V that includes a pair of mounting parts 23, a pair of pivot members 18, two pairs of mounting brackets 17, and an adapter 16. The crawler 210 of the crawler crane 200, which is mounted on the ground 300, is engaged with the engagement groove 24, which serves as a crawler engagement part. The reaction beam 20 functions to support the rotational reaction force during excavation by connecting the base frame 4 and the crawler 210 of the crawler crane 200.

[0045] As shown in Figure 4, the reaction beam 20 includes an upper surface 20a, a lower surface 20b, and a pair of outer surfaces 20c. The reaction beam 20 is formed in a hollow box shape by welding a plurality of iron plates together and extends in the longitudinal direction L. In plan view, the reaction beam 20 is formed in a shape symmetrical with respect to the central axis C2 extending in the longitudinal direction L. With respect to the width in the short direction S, the widths of the base end 21 and the tip end 22 are wider than the width of the middle part in the longitudinal direction L.

[0046] The engagement groove 24 is formed in a U-shape in plan view. The engagement groove 24 has a pair of inner surfaces 24a extending in the longitudinal direction L of the reaction beam 20. Of the pair of inner surfaces 24a, at least the inner surface 24a in the rotational direction R1 of the casing 100 is fitted with a pressure sensor 31 that detects the pressure that contacts the crawler 210. For example, a sheet-shaped piezoelectric sensor can be used as the pressure sensor 31.

[0047] A pair of mounting portions 23 protrude parallel to the longitudinal direction L from the base end 21 of the reaction beam 20. A rectangular block-shaped adapter 16 is fixed to the side of the base frame 4, and two pairs of mounting brackets 17 are fixed to the side of the adapter 16. The corresponding mounting portions 23 of the reaction beam 20 are fitted between each pair of mounting brackets 17.

[0048] Each mounting section 23 is connected to a corresponding pair of mounting brackets 17 by a pivot member 18 extending horizontally. The base end 21 of the reaction beam 20 is freely rotatable around the central axis C3 of the pivot member 18. Therefore, even if the base frame 4, which is subjected to a compressive reaction force, rises, the tip 22 of the reaction beam 20 does not exert any force that lifts the crawler 210.

[0049] To facilitate the insertion of each mounting portion 23 of the reaction beam 20 between the corresponding pair of mounting brackets 17 and to improve workability, a gap J is typically provided between the opposing surfaces of the mounting portion 23 and the mounting bracket 17. That is, the base end 21 of the reaction beam 20 can move by the amount of the gap J in the axial direction of the pivot member 18.

[0050] On the upper surface (horizontal plane) of the adapter 16 of the coupling mechanism V, a pair of strain sensors 32A and 32B are mounted in the portion adjacent to each pair of mounting brackets 17. The pair of strain sensors 32A and 32B are positioned symmetrically with respect to the central axis C2 extending in the longitudinal direction L in a plan view. For example, strain gauges can be used as strain sensors 32A and 32B.

[0051] The inventors of this application have found that when the reaction beam 20 supports the rotational reaction force, a large amount of strain is generated in and around the connecting mechanism V. Therefore, in this embodiment, a pair of strain sensors 32A and 32B are attached to the upper surface of the adapter 16 of the connecting mechanism V. The upper surface of the adapter 16 makes it easy to position the pair of strain sensors 32A and 32B and allows for stable detection. If the adapter 16 is not provided, and two pairs of mounting brackets 17 are directly provided on the sides of the base frame 4, the pair of strain sensors 32A and 32B may be attached to the upper surface of the base frame 4. Alternatively, the pair of strain sensors 32A and 32B may be attached to the outer surface of the outer mounting bracket 17 of each pair.

[0052] Figure 5 is a block diagram mainly showing the electrical configuration for controlling the hydraulic unit U. The controller 60, which is composed of a CPU, is connected to the operation panel 30, the pressing force sensor 31, a pair of strain sensors 32A and 32B, an acceleration sensor 33, a limit switch 34, and a stroke sensor 35, so that signals from each of them can be input. The stroke sensor 35 detects the stroke amount of the lifting cylinder 8.

[0053] Furthermore, the controller 60 is connected to the memory 36 so that necessary data can be input and output as signals. The memory 36 stores the value of the upper limit of the pressing force Fmax, which is appropriate for the total weight Wa of the casing 100, the lifting frame 5, the chuck frame 6, the chuck mechanism 7, and the chuck cylinder 9 (the weight Wb of the casing rotary press-fitting device 1 may be substituted), as correlation data. The memory 36 also stores various calculation formulas (the aforementioned formulas (1) and (2), and formulas (3) to (7) described later).

[0054] Although not shown in the diagram, the control panel 30 is provided with a driving mode selection knob for the operator to selectively choose between automatic and manual driving modes, a start switch, an input unit for the operator to input predetermined information, and a display unit for displaying various information. The pressing force sensor 31, strain sensors 32A and 32B, and acceleration sensor 33 each constitute acquisition means for acquiring information related to the rotation start behavior of the reaction force beam 20 around the central axis C1 of the casing 100.

[0055] The pressing force reference determination unit 61 determines whether or not the reaction force beam 20 has started rotating based on the change in pressure detected by the pressing force sensor 31. The strain amount reference determination unit 62 determines whether or not the reaction force beam 20 has started rotating based on the change in strain amount detected by strain sensors 32A and 32B. Furthermore, as shown in Figure 6, the strain amount reference determination unit 62 is configured to determine whether or not rotation has started based on the sum (εa + εb) of the strain amount εa detected by strain sensor 32A and the strain amount εb detected by strain sensor 32B, thereby improving detection accuracy. As shown in Figure 5, the acceleration reference determination unit 63 determines whether or not the reaction force beam 20 has started rotating based on the acceleration detected by the acceleration sensor 33.

[0056] The reaction force beam rotation suppression unit 64 is configured to suppress the rotation of the reaction force beam 20 by adjusting the hydraulic pressure supplied to the hydraulic motor 10 when at least one of the pressing force reference determination unit 61, strain amount reference determination unit 62, and acceleration reference determination unit 63 determines that the reaction force beam 20 has started to rotate.

[0057] Furthermore, the controller 60 is connected to the switching valve 41 and the relief valve 45 of the first hydraulic circuit 40. The controller 60 outputs a switching signal to the switching valve 41 to switch its operating position and outputs a setting signal to the relief valve 45 to set the relief set value RS1. In addition, the controller 60 is connected to the switching valve 51 and the relief valve 55 of the second hydraulic circuit 50. The controller 60 outputs a switching signal to the switching valve 51 to switch its operating position and outputs a setting signal to the relief valve 55 to set the relief set value RS2.

[0058] The processing flow of the controller 60 will be explained based on the flowchart in Figure 7.

[0059] First, in step S1, if the operator selects the automatic operation mode by operating the operation mode selection knob (not shown) on the control panel 30 (if YES is selected in step S1), the process proceeds to step S2. In step S2, the operator operates the input section of the control panel 30 to input the weight Wb of the casing rotary press-fitting device 1, the weight Wc of the crawler crane 200, the weight Wd of the casing 100, and the distance D from the central axis C1 of the casing 100 to the tip 22 of the reaction beam 20 (see Figure 3), and initial settings are performed.

[0060] Next, in step S3, the value of the friction coefficient μ stored in memory 36 is read. The friction coefficient μ is initially set to, for example, 0.3.

[0061] Next, in step S4, the value of the rotational torque upper limit Tmax is calculated using the following formula (3) stored in memory 36. Then, using the following formula (4) stored in memory 36, the value obtained by dividing the rotational torque upper limit Tmax calculated in formula (3) by the reduction ratio M of the reduction gear 11 is set as the set rotational torque TS of the hydraulic motor 10. The relief valve 45 of the first hydraulic circuit 40 is set to the relief set value RS1 corresponding to the set rotational torque TS.

[0062] Tmax = Wc × μ × D ... (3) TS = Tmax / M ···(4) The most severe condition for supporting rotational reaction force is when the base frame 4 is lifted, and the frictional resistance between the base plate 2 and the ground 300 due to the weight Wb of the casing rotary press-fitting device 1 cannot contribute to supporting the rotational reaction force. In that case, the rotational reaction force will be supported only by the frictional resistance between the crawler 210 and the ground 300 due to the weight Wc of the crawler crane 200. The reaction force support torque due to the weight Wc of the crawler crane 200 in this case corresponds to the right-hand side of equation (3). Therefore, the value of the right-hand side is set as the rotational torque upper limit value Tmax, and the set rotational torque TS is set to a value equal to the value obtained by dividing the rotational torque upper limit value Tmax by the reduction ratio M.

[0063] Furthermore, the value of the upper limit of the pushing force Fmax stored in memory 36 is read, and the read value of the upper limit of the pushing force Fmax is set as the value of the set pushing force FS. The relief valve 55 of the second hydraulic circuit 50 is set to the relief set value RS2 corresponding to the value of the set pushing force FS (the value of the upper limit of the pushing force Fmax). Specifically, using the aforementioned equation (1) or equation (2), the upward oil pressure GU or downward oil pressure GL required for the lifting cylinder 8 is determined, the value of the supply oil pressure corresponding to the determined upward oil pressure GU or downward oil pressure GL is determined, and the value of the determined supply oil pressure is set as the relief set value RS2.

[0064] Next, in step S5, the operator turns the start switch (not shown) on the control panel 30 to start automatic operation. Pressurized oil is supplied to the hydraulic motor 10 by switching the operating position of the switching valve 41 of the first hydraulic circuit 40, and pressurized oil is supplied to the required oil chambers (first oil chamber 81 or second oil chamber 82) of the lifting cylinder 8 by switching the operating position of the switching valve 51 of the second hydraulic circuit 50. As a result, the casing 100 is rotated and pressed into the ground 300.

[0065] Next, in step S6, the base frame 4 is monitored to determine whether it is in a predetermined floating state based on whether the limit switch 34 is turned on or not. If the predetermined floating state is not detected in step S6 (if NO in step S6), the process proceeds to step S8.

[0066] If a predetermined floating state is detected in step S6 (if YES in step S6), the relief set value RS2 of the relief valve 55 of the second hydraulic circuit 50 is set to a predetermined percentage or a predetermined value smaller so as to reduce the set pressing force FS (step S7). Then, the process proceeds to step S8.

[0067] In step S8, it is monitored whether or not the reaction beam 20 has started to rotate. If it is determined in step S8 that there is no rotation start behavior (the result in NO in step S8), the process proceeds to step S11.

[0068] If it is determined in step S8 that rotational start behavior has occurred (if YES in step S8), the relief set value RS1 of the relief valve 45 of the first hydraulic circuit 40 is set to a predetermined percentage or a predetermined value smaller in order to reduce the set rotational torque TS (rotational torque upper limit value Tmax) (step S9).

[0069] Next, in step S10, using equation (5) obtained by rearranging equation (3), the actual rotational torque value T1 (a value detected by a torque sensor not shown) at the time the rotational start behavior occurs is substituted into the rotational torque upper limit value Tmax on the right side of equation (5) to obtain the value of the friction coefficient μ, and the obtained value of the friction coefficient μ is stored in memory 36.

[0070] μ = Tmax / (Wc × D) ... (5) Alternatively, without using equation (5), the value of the friction coefficient μ may be updated to a predetermined percentage or a predetermined value smaller and stored in memory 36. The value of the friction coefficient μ stored in memory 36 will be used in the next step. Then, the process returns from step S10 to step S6 and is executed.

[0071] The process for detecting the rotation start behavior of the reaction beam 20 will be explained based on the flowchart in Figure 8 and the graphs in Figures 9A-9C.

[0072] Figure 9A shows the temporal change in the pressing force P detected by the pressing force sensor 31. Figure 9B shows the temporal change in the strain amount ε detected by the strain sensors 32A and 32B. Figure 9C shows the temporal change in acceleration α detected by the acceleration sensor 33.

[0073] First, as shown in Figure 9A, when there is no rotational start behavior of the reaction beam 20, the pressing force P detected by the pressing force sensor 31 is a constant base value P0. This is because the crawler 210 of the crawler crane 200 is positioned within the engagement groove 24 of the reaction beam 20 in a state where it is pressing against the pressing force sensor 31.

[0074] First, the base frame 4 rotates at a small angle around the central axis C1 of the casing 100 by the amount of the gap J (mounting play) between the mounting portion 23 of the reaction beam 20 and the mounting bracket 17 of the adapter 16, after which the rotational reaction force is transmitted from the base frame 4 to the reaction beam 20. As a result, the pressing force P detected by the pressing force sensor 31 increases. Then, if there is a rotational start behavior of the reaction beam 20, it is thought that the pressing force P detected by the pressing force sensor 31 will reverse from an increasing trend to a decreasing trend, and then decrease sharply.

[0075] Steps S81 to S83 are the flow of a pressing force reference determination process that detects whether or not rotation start behavior occurs based on the change in pressing force P detected by the pressing force sensor 31.

[0076] First, in step S81, it is detected whether or not there is a reversal from an increase in pressing force to a decrease in pressing force, based on the pressing force P detected by the pressing force sensor 31.

[0077] If it is determined in step S81 that there is an inversion (when YES in step S81), the process proceeds to step S82, and the pressing force drop rate RP is detected from the timing t1 of the inversion to the timing t2 after a predetermined elapsed time Δt (for example, 0.1 second) has elapsed. Assuming that the pressing force has dropped by ΔP (ΔP = P1 - P2) from the pressing force P1 (corresponding to the peak pressure) to the pressing force P2 during the predetermined elapsed time Δt, the pressing force drop rate RP is detected using the following formula (6).

[0078] RP = ΔP / Δt ···(6) Next, in step S82, it is determined whether the detected pressing force drop rate RP is equal to or greater than a predetermined drop rate Rk (for example, 20%). If the detected pressing force drop rate RP is equal to or greater than the predetermined drop rate Rk (RP ≧ Rk; when YES in step S83), it is determined that there is a rotation start behavior of the reaction force beam 20 (step S88). On the other hand, if no inversion is detected in step S81 (when NO in step S81), and in step S83, if the detected pressing force drop rate RP is less than the predetermined drop rate Rk (RP < Rk; when NO in step S83), the process proceeds to step S84.

[0079] Steps S84 to S86 are a flow of a strain amount reference determination process for detecting the presence or absence of a rotation start behavior of the reaction force beam 20 based on the change in the strain amount ε detected by the strain sensors 32A and 32B.

[0080] First, in step S84, based on the strain amount ε detected by the strain sensors 32A and 32B, it is detected whether there is an inversion from an increase in the strain amount to a decrease in the strain amount.

[0081] If it is determined in step S84 that there is an inversion (when YES in step S84), the process proceeds to step S85, and the strain amount drop rate Rε during the period from the inversion timing t1 to the timing t2 after a predetermined elapsed time Δt (for example, 0.1 seconds) has elapsed is detected. Assuming that the strain amount has dropped by Δη from the strain amount ε1 (corresponding to the peak strain amount) to the strain amount ε2 during the predetermined elapsed time Δt, the strain amount drop rate Rε is detected using the following formula (7).

[0082] Rε = Δη / Δt ···(7) Next, in step S86, it is determined whether or not the detected strain amount drop rate Rε is equal to or greater than a predetermined drop rate Rh (for example, 20%). If the detected strain amount drop rate Rε is equal to or greater than the predetermined drop rate Rh (Rε ≥ Rh; when YES in step S86), it is determined that there is a rotation start behavior of the reaction force beam 20 (step S88). On the other hand, if no inversion is detected in step S84 (when NO in step S84), and in step S86, if the detected strain amount drop rate Rε is less than the predetermined drop rate Rh (Rε < Rh; when NO in step S86), the process proceeds to step S87, which is an acceleration reference determination process.

[0083] In step S87, it is determined whether or not the acceleration α is detected by the acceleration sensor 33. If the acceleration α is detected (when YES in step S87), it is determined that there is a rotation start behavior of the reaction force beam 20. If the acceleration α is not detected (when NO in step S87), it is determined that there is no rotation start behavior of the reaction force beam 20 (step S89), and the process proceeds to step S11 in the flowchart of FIG. 7.

[0084] In step S11, it is monitored whether or not the stroke amount of the lifting cylinder 8 detected by the stroke sensor 35 has reached a predetermined stroke amount (for example, 50 cm). If it is determined in step S11 that the predetermined stroke amount has not been reached (when NO in step S11), the process returns to step S6.

[0085] If it is determined in step S11 that a predetermined stroke amount has been reached (if the answer is YES in step S11), the process proceeds to step S12 to determine whether a predetermined number of strokes (for example, 10 times) has been reached. If it is determined in step S12 that the predetermined number of strokes has not been reached (if the answer is NO in step S12), the process proceeds to step S13 to change the gripping position relative to the casing 100.

[0086] In step S13, first, the operating position of the switching valve 41 is switched to stop the supply of pressurized oil to the hydraulic motor 10, and the operating position of the switching valve 51 is switched to stop the supply of pressurized oil to the lifting cylinder 8. Next, the chuck cylinder 9 is extended to release the grip of the casing 100 by the chuck mechanism 7, and then the lifting cylinder 8 is extended to raise the lifting frame 5 and the chuck mechanism 7. Next, the chuck cylinder 9 is shortened to grip the casing 100 with the chuck mechanism 7. As a result, the gripping position of the casing 100 is shifted upward by the extension stroke of the lifting cylinder 8.

[0087] On the other hand, if it is determined in step S12 that a predetermined number of strokes has been reached (if the answer is YES in step S12), the operation (automatic operation) is terminated, and it is determined that the pushing in of one casing 100 having a predetermined length (e.g., 6 m) has been completed. Then, if necessary, the lower end of a new casing 100 is fixed to the upper end of the gripped casing 100, for example, with a special fixing bolt (not shown), and the extension operation (so-called jointing pipe) is performed.

[0088] According to this embodiment, as shown in Figure 7, by suppressing the rotation of the reaction beam 20 based on information related to the rotation start behavior of the reaction beam 20, it is possible to suppress displacement of the crawler crane 200 during excavation work. Therefore, it becomes unnecessary to interrupt the excavation work and return the crawler crane 200 to its correct position, thereby increasing work efficiency.

[0089] Furthermore, as shown in Figure 7, it is determined whether or not the reaction beam 20 has started to rotate (step S8 in Figure 7), and when it is determined that the reaction beam 20 has started to rotate, the set rotational torque TS is reduced (step S9 in Figure 7). This reduces the rotational torque applied to the casing 100 and thus reduces the rotational reaction force, thereby suppressing the rotation of the reaction beam 20.

[0090] As shown in Figure 4, a pressure sensor 31 is used to detect the pressure at the contact point between the crawler engagement portion (engagement groove 24) of the reaction beam 20 and the crawler 210. Based on the change in pressure detected by the pressure sensor 31, it is determined whether or not the reaction beam 20 is beginning to rotate. In contrast to the current situation where various specifications of the reaction beam 20 are used at each site, this method can reliably detect whether or not rotation is beginning regardless of the specifications of the reaction beam 20.

[0091] As shown in Figure 9A, the behavior of the reaction beam 20 when rotation begins is such that, with respect to the change in pressing force P detected by the pressing force sensor 31, a reversal occurs from an increase in pressing force to a decrease in pressing force, followed by a sharp drop in pressing force P. Therefore, when such a phenomenon occurs, it is determined that rotation has started. Specifically, as shown in Figure 9A and Figure 8 (steps S81 to S83), the pressing force decrease rate RP is detected from the reversal timing t1 to a predetermined elapsed time Δt, and when the detected pressing force decrease rate RP is greater than or equal to a predetermined decrease rate Rk, it is determined that rotation has started. This allows for accurate detection of whether or not rotation has started.

[0092] Furthermore, as shown in Figure 4, by placing a pressing force sensor 31 on at least the inner surface 24a on the side receiving the rotational reaction force (the inner surface 24a on the rotational direction R1 side) of the U-shaped engagement groove 24 which serves as the crawler engagement portion, the presence or absence of rotational initiation behavior can be detected effectively.

[0093] Furthermore, as shown in Figure 8, in addition to using the pressure detected by the pressing force sensor 31, the presence or absence of rotational initiation behavior of the reaction force beam 20 is detected using the strain amount ε(εa,εb) detected by the strain sensors 32A and 32B. This improves the accuracy of detecting the presence or absence of rotational initiation behavior of the reaction force beam 20.

[0094] As shown in Figure 9B, the behavior of the reaction beam 20 when rotation begins is such that, with respect to the change in strain amount ε detected by strain sensors 32A and 32B, a reversal occurs from an increase in strain amount to a decrease in strain amount, followed by a sharp drop in strain amount. Therefore, when such a phenomenon occurs, it is determined that rotation has started. Specifically, as shown in Figure 9B and Figure 8 (steps S84 to S86), the strain amount decrease rate Rε during a predetermined elapsed time Δt from the reversal timing t1 is detected, and it is determined that rotation has started when the detected strain amount decrease rate Rε is greater than or equal to a predetermined decrease rate Rh.

[0095] Furthermore, as shown in Figure 8 (step S87), the presence or absence of rotational initiation behavior of the reaction force beam 20 is detected not only using the pressing force P detected by the pressing force sensor 31 and the strain amount ε detected by the strain sensors 32A and 32B, but also using the acceleration α detected by the acceleration sensor 33. This improves the accuracy of detecting the presence or absence of rotational initiation behavior of the reaction force beam 20.

[0096] Furthermore, when the lifting state detection sensor (limit switch 34) detects a predetermined lifting state of the base frame 4, the set pressing force FS is reduced in response, thereby suppressing the lifting of the base frame 4. As a result, the frictional force between the base plate 2, on which the weight of the casing rotary press-fitting device 1 is loaded, and the ground 300 can be effectively used to resist the rotational reaction force, and consequently, the rotation of the reaction beam 20 can be effectively suppressed.

[0097] Furthermore, since a limit switch 34 is used as a sensor to detect the floating state, the floating state of the base frame 4 can be detected with a simple configuration.

[0098] Next, Figure 10 is a schematic plan view of a reaction beam 20Q in another embodiment of the present invention. The main differences between the reaction beam 20Q in Figure 10 and the reaction beam 20 in Figure 4 are as follows: The crawler engagement portion KK is composed of an engagement groove 25 that is triangular or trapezoidal in plan view, into which the front end of the crawler 210 is fitted. The engagement groove 25 has a pair of inner surfaces 25a that are inclined in opposite directions to each other with respect to the longitudinal direction L of the reaction beam 20.

[0099] Furthermore, the pressing force sensor includes a pair of pressing force sensors 31A and 31B, respectively, positioned on a pair of inner surfaces 25a of the engagement groove 25. The pair of pressing force sensors 31A and 31B are pressed by a pair of sides at the front end of the crawler 210. As shown in Figure 11, the pressing force reference determination unit 61 is configured to determine whether or not there is a rotation start behavior based on the sum (Pa + Pb) of the pressing force Pa detected by the pressing force sensor 31A and the pressing force Pb detected by the pressing force sensor 31A.

[0100] With this configuration, as shown in Figure 10, a pair of pressing force sensors 31A and 31B, positioned on the inner surfaces 25a of a pair of engagement grooves 25 which are triangular or trapezoidal in plan view, can detect the pressing force at two locations on both sides of the front end of the crawler 210. This improves the accuracy of detecting whether or not the reaction force beam 20 has started to rotate.

[0101] Furthermore, as shown in Figure 11, by determining whether or not there is rotation initiation behavior based on the sum (Pa+Pb) of the pressing forces Pa and Pb detected by a pair of pressing force sensors 31A and 31B, the accuracy of detecting whether or not there is rotation initiation behavior of the reaction force beam 20 can be further improved.

[0102] The present invention is not limited to the embodiments described above. For example, the acquisition means can detect the presence or absence of rotational initiation behavior if it includes at least one of a pressing force sensor, a strain sensor, and an acceleration sensor. Furthermore, the present invention can be modified in various ways within the scope of the claims. [Explanation of Symbols]

[0103] 1. Casing rotary press-fitting device 2 Base plate 3 Jacks 4 Base frame 5. Lifting frame 6 Chuck Frames 7. Chuck mechanism 8. Lifting cylinder (hydraulic cylinder) 10 Hydraulic motor 12 Hydraulic pumps 20 Reaction beam 20Q Reaction Beam 21 Proximal end 22 Tip 24 Engagement groove (crawler engagement part) 24a Inside surface 25 Engagement groove (crawler engagement part) 25a Inside surface 31. Pressing force sensor (acquisition means) 31A, 31B Pressure sensor (acquisition means) 32A, 32B Strain Sensor (Acquisition Method) 33. Accelerometer (acquisition means) 34. Limit switch (floating state detection sensor) 40. First Hydraulic Circuit 41 Switching valve 45 Relief valve 50. Second Hydraulic Circuit 51 Switching valve 55 Relief valve 60 Controllers 61 Pressing force reference determination unit 62 Distortion amount reference judgment section 63 Acceleration reference judgment section 64 Reaction force beam rotation suppression unit 100 casing 200 Crawler Crane 210 Crawler 300 ground C1 center axis C2 center axis E-engine F Pushing force FS setting force Fmax upper limit of indentation force J gap KK Crawler Engagement Part L Longitudinal direction M reduction ratio P,P1,P2,Pa,Pb Pressure force R1 Rotation direction RP pressure reduction rate RS1 Relief Set Value RS2 Relief Set Value Rε Strain reduction ratio TS Set rotational torque Tmax rotational torque upper limit U Hydraulic Unit V-coupling mechanism Wa,Wb,Wc,Wd Weight α acceleration ε, εa, εb, ε1, ε2 Strain amount μ coefficient of friction

Claims

1. A casing rotary press-in device for rotary press-in a casing into the ground, A base plate placed on the aforementioned ground, A base frame supported on the base plate via jacks, A lifting frame supported on the base frame so as to be able to move up and down, A chuck mechanism capable of gripping the casing, A hydraulic motor that applies rotational torque to the casing via the chuck mechanism, A hydraulic cylinder supports the lifting frame so that it can be raised and lowered relative to the base frame, and applies a pressing force to the casing into the ground via the lifting frame and the chuck mechanism, A hydraulic unit that supplies hydraulic pressure corresponding to a set rotational torque to the hydraulic motor and hydraulic pressure corresponding to a set pressing force to the hydraulic cylinder, A controller for controlling the hydraulic unit, A reaction beam that includes a base end connected to the base frame and a tip having a crawler engagement portion into which the crawler of a crawler crane placed on the ground engages, and which supports the rotational reaction force during excavation, The means includes an acquisition means for acquiring information relating to the rotation start behavior of the reaction beam about the central axis of the casing, A casing rotary press-fitting device, wherein the controller is configured to suppress the rotation of the reaction beam based on the information acquired by the acquisition means.

2. The controller includes a determination unit that determines whether or not the reaction force beam has started rotating based on the information acquired by the acquisition means, The casing rotary press-fitting apparatus according to claim 1, further comprising: a reaction beam rotation suppression unit that suppresses the rotation of the reaction beam by reducing the set rotation torque when the determination unit determines that the rotation start behavior has occurred.

3. The acquisition means includes a pressing force sensor disposed in the crawler engagement portion for detecting the pressing force generated at the contact portion between the crawler engagement portion and the crawler, The casing rotary press-fitting apparatus according to claim 2, wherein the determination unit includes a pressure reference determination unit that determines whether or not the rotation start behavior occurs based on the change in pressure detected by the pressure sensor.

4. The casing rotation pressure device according to claim 3, wherein the pressing force reference determination unit is configured to detect a reversal from an increase in pressing force to a decrease in pressing force based on the pressing force detected by the pressing force sensor, detect the percentage of decrease in pressing force during a predetermined elapsed time from the reversal, and determine that the rotation start behavior has occurred when the detected percentage of decrease in pressing force is equal to or greater than a predetermined percentage of decrease.

5. The crawler engagement portion has a pair of inner surfaces parallel to the longitudinal direction of the reaction beam and includes an engagement groove that is U-shaped in plan view into which the front end of the crawler is fitted. The casing rotary press-fitting device according to claim 3 or 4, wherein the pressing force sensor is positioned on at least the inner surface of the pair of inner surfaces of the engagement groove in the rotational direction of the casing.

6. The crawler engagement portion has a pair of inner surfaces inclined in opposite directions with respect to the longitudinal direction of the reaction beam, and includes an engagement groove that is triangular or trapezoidal in plan view into which the front end of the crawler is fitted. The casing rotary press-fitting apparatus according to claim 3 or 4, wherein the pressing force sensor includes a pair of pressing force sensors disposed on the pair of inner surfaces of the engagement groove, respectively.

7. The casing rotary press-fitting apparatus according to claim 6, wherein the pressing force reference determination unit is configured to determine whether or not the rotation start behavior occurs based on the sum of the pressing forces detected by the pair of pressing force sensors.

8. The acquisition means further includes a strain sensor for detecting the amount of strain generated in the connecting mechanism that connects the base end of the reaction beam and the base frame, The casing rotary press-fitting apparatus according to claim 3 or 4, wherein the determination unit further includes a strain amount reference determination unit that determines whether or not the rotation start behavior occurs based on the change in the amount of strain detected by the strain sensor.

9. The strain amount reference determination unit is configured to detect a reversal from strain amount increase to strain amount decrease based on the strain amount detected by the strain sensor, detect the strain amount decrease rate during a predetermined elapsed time from the reversal, and determine that the rotation start behavior has occurred when the detected strain amount decrease rate is equal to or greater than a predetermined decrease rate, as described in claim 8.

10. The acquisition means further includes an acceleration sensor that detects acceleration in the radial direction about the central axis of the casing, The casing rotary press-fitting apparatus according to claim 8, wherein the determination unit includes an acceleration reference determination unit that determines whether or not the rotation start behavior occurs based on the acceleration detected by the acceleration sensor.

11. The casing rotary press-fitting apparatus according to claim 1 or 2, wherein the acquisition means includes at least one of a pressing force sensor disposed in the crawler engagement portion for detecting the pressing force generated at the contact portion between the crawler engagement portion and the crawler, a strain sensor for detecting the amount of strain generated in the reaction force beam, and an acceleration sensor for detecting the acceleration in the radial direction about the central axis of the casing.

12. The system further includes a lift state detection sensor that detects a predetermined lift state of the base frame from the base plate, The casing rotary press-fitting apparatus according to any one of claims 1 to 4, wherein the controller is configured to reduce the set pressing force in response to the detection of a predetermined lifting state by the lifting state detection sensor.

13. The casing rotary press-fitting apparatus according to claim 12, wherein the lift-up state detection sensor includes a limit switch that turns on when the base frame lifts up by a predetermined amount from the base plate.

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