Safety device of holding-type pole erection vehicle

Abstract

To provide a safety device of a holding-type pole erection vehicle that can prevent interference between a pole-shaped object held by a holding part and the ground.SOLUTION: A safety device of a holding-type pole erection vehicle includes a boom 13 that is mounted on the vehicle body so as to be able to go up and down, extend and retract, and rotate freely, a holding part 81 that is provided at the tip of the boom 13 and holds a power pole P, and a support mechanism for a holding device 50 that is provided between the tip of the boom 13 and the holding part 81 and changes the position and posture of the holding part 81 relative to the tip of the boom 13. In a state in which the holding part 81 holds the power pole P, if the height H of the holding part 81 above the ground is equal to or lower than a predetermined threshold height SH, the specified operation of the support mechanism of the holding device 50 is restricted.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a safety device for a gripping type pole erection vehicle equipped with a gripping portion for gripping a pole-shaped object such as a utility pole. [Background technology]

[0002] As a type of work vehicle, a pole hole digger vehicle is known that includes a rotating platform provided on the vehicle body so as to be freely rotatable, a boom provided on the rotating platform so as to be freely raised and lowered, an auger device attached to the boom for digging a pole hole for erecting a utility pole, and a gripping device provided at the tip of the boom for gripping a pole-shaped object such as a utility pole (see, for example, Patent Document 1). When digging a pole hole in the ground using this gripping type pole hole digger vehicle, the boom is appropriately operated with the auger device suspended from the tip of the boom, and the auger device is rotated at a predetermined digging position to form a pole hole of a predetermined depth. After the excavation of the pole hole is completed, the auger device is raised and stored on the side of the boom, and the pole is gripped by a gripping part provided on the gripping device that can be opened and closed freely, and with the pole gripped, the boom is operated appropriately and the gripping part is bent, extended, swiveled, and rotated to align the pole in the excavated pole hole and directly erect it. This type of gripping-type pole hole digger vehicle allows the entire pole erection work to be carried out more efficiently than when the pole is hoisted using a winch or crane. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 5-27190 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above pole erection work, after the utility pole placed horizontally on the ground is gripped by the gripper, it is necessary to move the utility pole held by the gripper to the position of the pole erection hole and adjust the posture to be perpendicular to the ground. However, since the utility pole held by the gripper is a long object, there is a problem that the end of the utility pole may interfere with the ground when changing the position or posture of the utility pole.

[0005] The present invention has been made in consideration of such problems, and aims to provide a safety device for a gripping-type pole erection vehicle that can prevent interference between the pole-shaped object gripped by the gripping part and the ground. [Means for solving the problem]

[0006] In order to solve the above problems, the safety device for a gripping type pole erection vehicle of the present invention is characterized in that it comprises a travelling body, a boom mounted on the body so as to be able to rise and fall, extend and retract and rotate freely, a gripping section mounted on the tip of the boom for gripping a pole-shaped object, a support mechanism mounted between the tip of the boom and the gripping section for changing the position and attitude of the gripping section relative to the tip of the boom, a height detection section for detecting the height of the gripping section, an operation device for performing operations to operate the boom and the support mechanism, an operation control section for operating the boom and the support mechanism in accordance with the operation of the operation device, and a regulating section for regulating a predetermined operation of the support mechanism when the height of the gripping section detected by the height detection section when the gripping section is gripping the pole-shaped object is below a predetermined threshold height.

[0007] In the safety device of the gripping-type pole erection vehicle configured as described above, it is preferable to provide an input device for inputting information regarding the length of the pole, and a threshold height setting unit for setting the threshold height based on the information regarding the length of the pole inputted in the input device.

[0008] In addition, the safety device of the gripping-type pole erection vehicle configured as described above may be provided with a length detection device that detects information regarding the length of the pole-like object, and a threshold height setting unit that sets the threshold height based on the information regarding the length of the pole-like object detected by the length detection device.

[0009] Furthermore, in the safety device of the grip-type pole erection vehicle configured as described above, it is preferable that the length detection device comprises a transmitter provided on the pole-shaped object and a receiver provided on the vehicle body to receive radio waves from the transmitter, the transmitter having a first radio wave transmitter provided at the center of gravity position in the central axis direction of the pole-shaped object and a second radio wave transmitter provided at an end position in the central axis direction of the pole-shaped object, and is equipped with a transmission position calculation unit that calculates the positions of the first radio wave transmitter and the second radio wave transmitter relative to the vehicle body based on the reception strength of the radio wave signals from the first radio wave transmitter and the second radio wave transmitter received by the receiving unit, and a pole length calculation unit that calculates the length from the center of gravity position in the central axis direction of the pole to the end position as information regarding the length of the pole-shaped object based on the positions of the first radio wave transmitter and the second radio wave transmitter relative to the vehicle body calculated by the transmission position calculation unit.

[0010] In addition, the safety device of the gripping-type pole erection vehicle configured as described above may be provided with an input device for inputting information regarding the threshold height, and a threshold height setting unit for setting the threshold height based on the information regarding the threshold height inputted in the input device.

[0011] In addition, in the safety device of the gripping type pole erection vehicle configured as described above, it is preferable that the device is provided with a gripping judgment unit which judges whether the gripping portion has gripped the pole-shaped object, and the regulating unit regulates the specified operation when the gripping judgment unit determines that the gripping portion has gripped the pole-shaped object and the height of the gripping portion detected by the height detection unit is equal to or less than the threshold height.

[0012] In addition, in the safety device of the gripping-type pole erection vehicle configured as described above, it is preferable that a gripping portion inclination angle detection unit is provided which detects the inclination angle of the gripping portion with respect to the horizontal plane, and that the regulating unit regulates the specified operation when the inclination angle of the gripping portion with respect to the horizontal plane detected by the gripping portion inclination angle detection unit exceeds a predetermined angle and when the height of the gripping portion detected by the height detection unit is equal to or lower than the threshold height. Effect of the Invention

[0013] According to the safety device of the gripping type pole erection vehicle of the present invention, when the height of the gripping part above the ground is below a threshold height, the specified operation of the support mechanism of the gripping device is regulated, thereby preventing the pole-shaped object gripped by the gripping part from interfering with the ground due to incorrect operation by the worker (preventing the pole-shaped object from interfering with the ground, which would cause the vehicle body to tilt or the pole-shaped object to be damaged), thereby improving the safety of pole erection work.

[0014] In addition, with the safety device of the gripping type pole erection vehicle of the present invention, even if the length of the pole-like object to be erected varies depending on the application or region, by setting a threshold height according to the length of the pole-like object to be erected, it is possible to reliably prevent the pole-like object gripped by the gripping portion from interfering with the ground, regardless of the length of the pole being erected, thereby further improving the safety of pole erection work. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a side view of the gripping-type pole hole digging vehicle according to the present embodiment. [Diagram 2] FIG. 2 is a plan view of the above-mentioned gripping-type pole hole digging vehicle. [Diagram 3] FIG. 2 is a side view showing the use state of the above-mentioned grip-type hole digging pole construction vehicle. [Figure 4] This is an oblique view of a gripping device provided on the above-mentioned gripping-type hole digging pole construction vehicle. [Diagram 5] FIG. 2 is a perspective view of a main part of the gripping device as viewed from the right. [Figure 6] FIG. 2 is a perspective view of a main part of the gripping device as viewed from the left. [Figure 7] FIG. 2 is a cross-sectional view of the gripping device. [Figure 8] FIG. 2 is a vertical cross-sectional view of the gripping device. [Figure 9] FIG. 2 is a functional block diagram of the safety device of the first embodiment. [Figure 10] FIG. 2 is a schematic diagram showing a state in which the gripping portion of the gripping device grips the center of gravity of a utility pole. [Figure 11] FIG. 1A is a schematic diagram showing a state when the height of the gripping part above the ground is equal to or less than a threshold height, and FIG. 1B is a schematic diagram showing a state when the height of the gripping part above the ground is greater than the threshold height. [Figure 12] FIG. 4 is a functional block diagram of a safety device according to a first modified example of the first embodiment. [Figure 13] FIG. 1A is a schematic diagram showing the divided pillar of the first modified example, and FIG. 1B is a schematic diagram for explaining the alignment of the divided pillar of the first modified example. [Figure 14] FIG. 11 is a functional block diagram of a safety device according to a second modified example of the first embodiment. [Figure 15] FIG. 11 is a functional block diagram of a safety device according to a second embodiment. [Figure 16] FIG. 13 is a schematic diagram showing a utility pole length detection device of a safety device according to a second embodiment. [Figure 17] FIG. 11 is a functional block diagram of a safety device according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. First, the overall configuration of a grip-type pole-digging vehicle 1 according to this embodiment will be described with reference to Figs.

[0017] As shown in Fig. 1, the grip-type post hole digger 1 has a driver's cabin 7 at the front of the vehicle body 2, and is constructed based on a truck vehicle that can run on a pair of left and right tires and wheels 5 arranged at the front and rear of the vehicle body 2. Jacks 9 for lifting and supporting the vehicle body 2 are arranged at four points on the front, rear, left and right of the vehicle body 2. Each jack 9 lifts and supports the vehicle body 2 by driving a jack cylinder (not shown) provided inside it to extend downward, thereby stabilizing the entire vehicle body 2. The jacks 9 are operated by operating a jack operating device (not shown) provided at the rear of the vehicle body 2.

[0018] A swivel base 12 is provided in a mounting area behind the driver's cabin 7 on the vehicle body 2, and is driven by a swivel motor 14 (see FIG. 9) and configured to be horizontally rotatable about a vertical axis. The swivel base 12 includes a substantially disk-shaped turntable 12a supported on the vehicle body 2 so as to be horizontally rotatable, and a support pillar 12b erected on the turntable 12a. The base end of a boom 13 is attached to the support pillar 12b of the swivel base 12 so as to be vertically swingable (raise and lower).

[0019] The boom 13 has a configuration in which, from the swivel base 12 side, a base end boom 13a, an intermediate boom 13b, and a tip end boom 13c are nested together, and the boom 13 can be extended and retracted in the axial direction (longitudinal direction) by driving a telescopic cylinder 15 (see FIG. 9) provided inside the boom 13 to extend and retract. A hoisting cylinder 16 is provided between the base end boom 13a and the swivel base 12, and by driving the hoisting cylinder 16 to extend and retract, the entire boom 13 can be raised and lowered in the upper and lower planes (vertical planes).

[0020] An auger device 20 for excavating a post hole is attached to the boom 13 via an auger support 17 that can be selectively connected to the base end boom 13a and the tip end boom 13c. The auger device 20 includes an auger motor 21 with a reduction gear and a drive shaft for rotating the auger motor 21. and an earth auger 22 that is rotated about an axis by being rotated in a direction perpendicular to the ground. Also, an auger storage device 18 that holds the auger device 20 in a stored state is disposed on the side of the base boom 13a. The auger device 20 is attached to the auger support 17 so as to be swingable up and down within a vertical plane, and can be swung between a stored position in which the auger device 20 is stored along the side of the base boom 13a by the auger storage device 18, and a working position in which the auger device 20 is removed from the auger storage device 18 and the earth auger 22 is in a position approximately vertical to the ground.

[0021] When the auger device 20 is used, as shown in I of Fig. 3, the auger support 17 is connected to the tip boom 13c, and the auger device 20, detached from the auger storage device 18, is swung to the working position (the earth auger 22 is in a substantially vertical position relative to the ground), and the earth auger 22 is rotated while the boom 13 is moved downward linearly in conjunction with the lowering and retracting operations, thereby enabling excavation work for a pole hole. On the other hand, when the auger device 20 is not used, as shown in II of Fig. 3, the auger support 17 is connected to the base boom 13a, and the auger device 20 is stored and held in a storage position along the side of the base boom 13a by the auger storage device 18. When the auger device 20 is in the storage position, various work such as pole erection work (indicated by the symbol P in Fig. 3: the same applies below) and obstacle relocation work can be performed using the gripping device 50 described later.

[0022] A boom head 19 is fixed to the tip of the tip boom 13c. A gripping device 50 for gripping an object (pillar-shaped object) such as a utility pole P or a tree is attached to this boom head 19. The configuration of this gripping device 50 will be described with additional reference to Figs. 4 to 8. In Figs. 7 to 8, hatching showing cross sections is omitted to make the drawings easier to see. For ease of explanation, the directions of the illustrated front-rear, left-right, and up-down arrows will be referred to as the front-rear direction, left-right direction, and up-down direction, based on the attitude of the gripping device 50 shown in Fig. 4.

[0023] The gripping device 50 is configured to include an arm 51 attached to the boom head 19 so as to be able to swing up and down (bend and stretch), a first joint member 60 attached to the tip of the arm 51 so as to be able to swing up and down (vertical swing operation), a second joint member 70 attached to the first joint member 60 so as to be able to swing left and right (horizontal swing operation), and a gripper 80 attached to the second joint member 70 so as to be able to rotate. In this embodiment, a support mechanism for changing the attitude of a gripping portion 81 of the gripper 80 is configured by the arm 51, the first joint member 60, the second joint member 70, an arm cylinder 55 described below, a vertical swing cylinder 62, a horizontal swing cylinder 71, a gripper motor 79, etc.

[0024] One axial (longitudinal) end of the arm 51 is pivotally connected to the boom head 19 via a connecting pin 52, and the other axial (longitudinal) end is pivotally connected to a first joint member 60 via a connecting pin 53. An arm cylinder 55 is attached between the boom head 19 and the arm 51. A rod side end of the arm cylinder 55 is pivotally connected to the boom head 19 via a connecting pin 56. A bottom side end of the arm cylinder 55 is pivotally connected to the arm 51 via a connecting pin 57. By driving the arm cylinder 55 to extend and retract, the arm 51 is configured to be able to swing (bend and extend) in the vertical direction around the connecting pin 52 relative to the boom head 19.

[0025] The first joint member 60 is formed in a bifurcated shape with an open tip, and the second joint member 70 is pivotally connected to both ends of the bifurcated shape via a pair of upper and lower connecting pins 61. A vertical swivel cylinder 62 is provided between the first joint member 60 and the arm 51. The bottom side end of the vertical swivel cylinder 62 is pivotally connected to the base end side of the arm 51 via a connecting pin 63. The rod side end of the vertical swivel cylinder 62 is pivotally connected to the upper end side of the first joint member 60 via a connecting pin 64. The vertical swivel cylinder 62 is driven by an extension and retraction mechanism. By moving the connecting pin 53, the first joint member 60 can be swung up and down relative to the arm 51 around the connecting pin 53 (vertical swingable).

[0026] The second joint member 70 is supported so as to be sandwiched from above and below by the first joint member 60. A horizontal swivel cylinder 71 is provided at the upper end of the first joint member 60. The bottom side end of the horizontal swivel cylinder 71 is pivotally connected to the tip end of the first joint member 60, and the rod side end is pivotally connected to the rear end of the second joint member 70. By driving the horizontal swivel cylinder 71 to extend and retract, the second joint member 70 is configured to be freely swingable (horizontally swivelable) in the left-right direction relative to the first joint member 60, centered on the connecting pin 61.

[0027] The gripper 80 includes a gripping portion 81 that grips an object, a gripper housing 86 that supports the gripping portion 81 and is rotatably mounted on the second joint member 70, and an opening / closing mechanism 93 that opens and closes the gripping portion 81.

[0028] The gripping portion 81 includes a pair of gripping claws 82 and a pair of upper and lower support plate portions 83 that support the pair of gripping claws 82 so as to be openable and closable in a direction (opening / closing direction) in which the pair of gripping claws 82 approach or move away from each other. The gripping claws 82 are configured to be able to grip various objects (pillar-shaped objects) such as utility poles P and trees. The base ends of the gripping claws 82 are pivotally connected to the upper and lower support plate portions 83 via connecting pins 84. Alternating notches 82a and 82b are formed in the tips of the gripping claws 82, and these tips are configured to be able to cross (overlap) each other. The support plate portion 83 is provided with a flat bracket 85 for detachably mounting an attachment (not shown) (for example, a tree felling device for felling trees).

[0029] The gripper housing 86 includes a support tube portion 87 connected to the upper and lower support plate portions 83 and supported rotatably on the second joint member 70, and a cylinder bracket portion 92 fixed to the base end side of the support tube portion 87 and disposed between the first joint member 60 and the second joint member 70.

[0030] The support cylinder 87 has a double structure including an inner cylinder 88 formed in a hollow rectangular cylinder shape and an outer cylinder 89 formed in a hollow cylindrical shape provided on the outer periphery of the inner cylinder 88. A sliding member 95 of an opening / closing mechanism 93 described later is attached to the inner periphery of the inner cylinder 88 so as to be slidable in the front-rear direction. A worm wheel 90 is attached to the outer periphery of the outer cylinder 89 so as to be concentric with the outer cylinder 89. The worm wheel 90 is engaged with a worm pinion 91 supported rotatably inside the second joint member 70. A gripper motor 79 is attached to the upper end of the second joint member 70, and the worm pinion 91 is connected to the output shaft of the gripper motor 79 via a reducer. When the gripper motor 79 is rotated in the forward direction, the entire gripper 80 rotates in a predetermined direction around the rotation axis J (see FIG. 7) via the worm pinion 91 and the worm wheel 90. On the other hand, when the gripper motor 79 is driven to rotate in the reverse direction, the entire gripper 80 rotates in the opposite direction to the predetermined direction around the rotation axis J (see FIG. 7) via the worm pinion 91 and the worm wheel 90. In the posture of the gripping device 50 shown in FIG. 4, the direction of the rotation axis J of the gripper 80 (gripping portion 81) corresponds to the front-rear direction, and the opening / closing direction (gripping direction) of the gripping portion 81 corresponds to the left-right direction.

[0031] The opening / closing mechanism 93 includes a pair of link members 94, a sliding member 95 linked and connected to the pair of link members 94, and a gripper cylinder 99 that slides the sliding member 95 back and forth. One end of each link member 94 is pivotally connected to the middle part of the gripping claw 81 via a connecting pin 96. The pair of link members 94 are pivotally connected to the tip of the sliding member 95 via a connecting pin 97 with the other ends of the link members 94 overlapping each other vertically. The sliding member 95 is inserted into the hollow portion of the inner cylindrical portion 88 and is attached so as to be slidable (reciprocating) along the inner peripheral surface of the inner cylindrical portion 88. A slider 98 made of synthetic resin is attached between the outer peripheral surface of the sliding member 95 and the inner peripheral surface of the inner cylindrical portion 88 to guide the sliding (reciprocating movement) of the sliding member 95. A rod side end of a gripper cylinder 99 is connected to a base end of the sliding member 95. The bottom side end of the gripper cylinder 99 is connected to a cylinder bracket portion 92 of the gripper housing 86. When the gripper cylinder 99 is extended, the sliding member 95 slides in the extension direction, and the link members 94 swing in a direction away from each other. As a result, the gripping claws 82 swing in the opening direction with the connecting pin 84 as a fulcrum (the gripping claws 82 operate in the opening direction (opening operation)), and the grip of a pole-shaped object (target object) such as a utility pole P can be released. On the other hand, when the gripper cylinder 99 is driven to contract, the sliding member 95 slides in the contraction direction, and the link members 94 swing in a direction approaching each other. As a result, the gripping claws 82 swing in the closing direction with the connecting pin 84 as a fulcrum (the gripping claws 82 operate in the closing direction (closing operation)), making it possible to grip a pole-shaped object (target object) such as a utility pole P. Note that the opening / closing mechanism 93 is configured symmetrically, so that the pair of gripping claws 82 open and close symmetrically.

[0032] An operator's seat 30 for operating each of the working devices (the swivel table 12, the boom 13, the auger device 20, and the gripping device 50) is provided immediately behind the driver's cabin 7 in the vehicle body 2 and in front of the swivel table 12. In front of the operator's seat 30 is provided an operating device 31 that can be operated by an operator while remaining seated. As shown in FIG. 9, the operating device 31 is provided with a boom rotation and hoisting operation lever 32a for rotating and raising the boom 13, a boom extension and contraction operation lever 32b for extending and contracting the boom 13 and bending and extending the arm 51, an auger operation lever 32c for rotating the earth auger 22, a gripper vertical swing operation lever 32d for vertically swinging the gripper 81, a gripper horizontal swing operation lever 32e for horizontally swinging the gripper 81, a gripper rotation operation lever 32f for rotating the gripper 81, and a gripper opening and closing operation lever 32g for opening and closing the gripper 81.

[0033] The operating device 31 is also provided with a mode selection switch 33, as shown in FIG. 9. The mode selection switch 33 is configured as a toggle switch that can be switched to either a neutral position or a tilted position (so that the switched operating position is maintained even if the operator releases his / her hand). When the mode selection switch 33 is selected to the neutral position, a normal mode is set, and when the mode selection switch 33 is selected to the tilted position, a gripper vertical operation mode is set. The normal mode is a mode in which the hydraulic actuators are independently operated in response to the operation of each of the operating levers 32a to 32g, and the boom 13 can be raised, retracted, and rotated, the auger device 20 (earth auger 22) can be rotated, the arm 51 can be bent and extended, and the gripper 81 can be swung vertically, horizontally, rotated, opened, and closed, etc., individually. The gripper vertical operation mode is a mode in which the boom hoisting cylinder 16, the telescopic cylinder 15, and the vertical swing cylinder 62 are linked in response to operation of the boom rotation hoisting operation lever 32a, thereby allowing the gripper 81 to move linearly in the vertical direction (up and down).

[0034] Here, as shown in FIG. 9, the operating mechanisms for the swivel base 12, boom 13, auger device 20, gripping device 50, etc., are configured with a controller 100 that receives operation signals from an operating device 31 and controls the swivel motor 14, telescopic cylinder 15, hoisting cylinder 16, auger motor 21, arm cylinder 55, vertical swing cylinder 62, horizontal swing cylinder 71, gripper motor 79, and gripper cylinder 99 (hereinafter collectively referred to as "hydraulic actuators"), and a hydraulic unit 110 that supplies hydraulic oil to drive these hydraulic actuators.

[0035] An operation signal output by the operation of the operation device 31 (operation levers 32a to 32g) is The operation signal is input to the controller 100. The controller 100 outputs a command signal corresponding to the operation signal to the hydraulic unit 110 (control valve 112).

[0036] The hydraulic unit 110 includes a hydraulic pump 111 that discharges hydraulic oil, and a control valve 112 that controls the supply direction and supply amount of hydraulic oil supplied from the hydraulic pump 111 to each hydraulic actuator. The hydraulic pump 111 is driven by power taken from the vehicle engine via a PTO mechanism (not shown). The control valve 112 includes an electromagnetic proportional control valve V1 corresponding to the swing motor 14, an electromagnetic proportional control valve V2 corresponding to the telescopic cylinder 15, an electromagnetic proportional control valve V3 corresponding to the elevation / depression cylinder 16, an electromagnetic proportional control valve V4 corresponding to the auger motor 21, an electromagnetic proportional control valve V5 corresponding to the arm cylinder 55, an electromagnetic proportional control valve V6 corresponding to the vertical swing cylinder 62, an electromagnetic proportional control valve V7 corresponding to the horizontal swing cylinder 71, an electromagnetic proportional control valve V8 corresponding to the gripper motor 79, and an electromagnetic proportional control valve V9 corresponding to the gripper cylinder 99. Based on a command signal from the controller 100, this control valve 112 electromagnetically drives the spools of each electromagnetic proportional control valve V1 to V9 to control the supply direction and amount of hydraulic oil supplied from the hydraulic pump 111 to each hydraulic actuator, and controls the drive direction and drive speed of each hydraulic actuator (controlling the operating direction and operating speed of the swivel table 12, boom 13, auger device 20, and gripping device 50).

[0037] [First embodiment] Next, a safety device of the first embodiment will be described. As shown in Fig. 9, the safety device of the first embodiment is mainly composed of a utility pole length input device 34, a boom hoisting angle detector 120, a boom extension amount detector 121, a boom rotation angle detector 122, an arm bending angle detector 123, a gripper vertical swing angle detector 124, a gripper horizontal swing angle detector 125, a gripper tilt angle detector 126, a gripper cylinder pressure detector 127, and a controller 100.

[0038] The safety device of the first embodiment is equipped with a function for preventing interference with the utility pole P, which will be described in detail later. Here, the utility pole P to be grasped is placed horizontally (laying on its side) on the ground at the work site before the start of pole erection work (before being grasped by the gripping part 81). This utility pole P is formed in a long cylindrical shape extending along the central axis direction, and has a tapered shape that tapers at a predetermined ratio (for example, 1 / 75) from the base end side to the tip end side in the central axis direction.

[0039] The utility pole length input device 34 is provided on the operation device 31. The utility pole length input device 34 is composed of, for example, a touch panel type liquid crystal display, and is configured to be able to display a predetermined setting input screen. This setting input screen is a screen for setting and inputting the length from the center of gravity position of the utility pole P to the base end position (referred to as the "base end side length") as the length of the utility pole P to be erected. Note that, as shown in FIG. 10, this base end side length of the utility pole P corresponds to the distance from the center C (proper gripping position) of the gripping part 81 to the base end position of the utility pole P when the gripping part 81 grips the center of gravity position (proper gripping position) of the utility pole P. This setting input screen displays a numeric keypad and display buttons (for example, buttons such as △ and ▽) that instruct to increase and decrease numerical values, thereby enabling numerical value input via the touch panel (i.e., the worker can input the base end side length of the utility pole P as a numerical value). For example, the worker can input the length (design value) from the center of gravity position to the base end position described in the utility pole specifications (dimension table) of the utility pole P as the base end length, or can input the measurement value obtained by actually measuring the length from the center of gravity position to the base end position of the utility pole (actual object) P as the base end length. The information (numerical information) on the base end length of the utility pole P inputted in this utility pole length input device 34 is output to the controller 100.

[0040] The boom hoisting angle detector 120 is provided in the base boom 13a and detects the hoisting of the boom 13. The boom extension detector 121 is provided at the base end of the base boom 13a and detects the length (extension) of the boom 13. The boom rotation angle detector 122 is provided on the vehicle body 2 and detects the rotation angle of the boom 13 (swivel base 12) relative to the vehicle body 2. The arm bending / extending angle detector 123 is provided near the connection (connecting pin 52) between the boom head 19 and the arm 51 and detects the bending / extending angle of the arm 51 relative to the boom head 19 (the sandwiching angle formed by the boom head 19 and the arm 51). The gripper vertical swing angle detector 124 is provided near the connection (connecting pin 53) between the arm 51 and the first joint member 60 and detects the vertical swing angle (swing angle) of the first joint member 60 relative to the arm 51. The gripper lateral swing angle detector 125 is provided in the vicinity of the connection (connecting pin 61) between the first joint member 60 and the second joint member 70, and detects the lateral swing angle (swing angle) of the second joint member 70 relative to the first joint member 60. These detectors 120-125 are electrically connected to the controller 100, and output voltage signals (detection signals) to the controller 100 according to the detected information (the hoisting angle, extension amount, and rotation angle of the boom 13, the bending and extension angle of the arm 51, the vertical swing angle, and lateral swing angle of the gripper 81).

[0041] The grip part inclination angle detector 126 is attached to the upper surface of the grip part 81 (support plate part 83). The grip part inclination angle detector 126 is a two-axis inclination angle detector that detects the inclination angle in the left-right direction and the inclination angle in the front-back direction as the inclination angle of the grip part 81 with respect to the horizontal plane. The grip part inclination angle detector 126 is electrically connected to the controller 100, detects the inclination angle in the left-right direction and the inclination angle in the front-back direction of the grip part 81, and outputs a voltage signal (detection signal) according to the detected inclination angle to the controller 100. Note that, as a modified example, instead of the grip part inclination angle detector 126, a grip part rotation angle detector that detects the rotation angle of the grip part 81 around the rotation axis J may be provided.

[0042] The gripper cylinder pressure detector 127 is provided in an oil passage connecting the electromagnetic proportional control valve V9 and the rod side oil chamber of the gripper cylinder 99, and detects the pressure of the hydraulic oil supplied to the rod side oil chamber of the gripper cylinder 99 (the pressure of the rod side oil chamber). This gripper cylinder pressure detector 141 detects the pressure of the rod side oil chamber of the gripper cylinder 99, and outputs a voltage signal (detection signal) corresponding to the detected pressure to the controller 100. Here, the detected pressure detected by this gripper cylinder pressure detector 141 is in a proportional relationship with the gripping force of the gripping portion 81 (the force with which the gripping portion 81 grips the utility pole P). Therefore, as will be described in detail later, the grip determination unit 103 of the controller 100 determines whether or not the gripping portion 81 is gripping the utility pole P based on this detected pressure.

[0043] The controller 100 includes a position calculation unit 101, an operation control unit 102, a grip determination unit 103, a tilt determination unit 104, a threshold height setting unit 105, and a regulation unit 106.

[0044] The position calculation unit 101 calculates the position of the tip of the boom 30 relative to the vehicle body 2 based on detection information from the boom hoisting angle detector 120, the boom extension amount detector 121, and the boom rotation angle detector 122. The position calculation unit 101 also calculates the position and attitude (direction) of the gripper 81 relative to the vehicle body 2 based on detection information from the boom hoisting angle detector 120, the boom extension amount detector 121, the boom rotation angle detector 122, the arm bending / extending angle detector 123, the gripper vertical swing angle detector 124, the gripper horizontal swing angle detector 125, and the gripper tilt angle detector 126. Here, "the position of grip portion 81" refers to the position of grip portion 81 (more specifically, the position of center C of grip portion 81 shown in FIG. 7) expressed in an XYZ coordinate system (orthogonal three-axis coordinate system) with the rotation center of turntable 12a as the origin, the vehicle width direction (left and right direction) of vehicle body 2 as the X axis, the vehicle length direction (front and rear direction) of vehicle body 2 as the Y axis, and the vehicle height direction (up and down direction) of vehicle body 2 as the Z axis. "The attitude (orientation) of grip portion 81" refers to the attitude (orientation) of grip portion 81 in the above-mentioned XYZ coordinate system with the rotation center of turntable 12a as the origin.

[0045] Furthermore, the position calculation unit 101 calculates the height H (see FIG. 11) of the grip part 81 from the ground based on the calculated position information (Z coordinate value) of the grip part 81. The position calculation unit 101 calculates the height H (height from the ground) of the grip part 81 from the ground by adding the calculated Z coordinate value of the grip part 81 (height from the turntable 12 to the center C of the grip part 81) to the known height from the ground to the turntable 12a.

[0046] The operation control section 102 controls the driving of each hydraulic actuator in accordance with an operation signal (operation command) output from the operation device 31, based on the operation mode selected by the mode selection switch 33. Each operation mode will be described below.

[0047] When the mode selection switch 33 is set to the normal mode and the operation levers 32a to 32g are operated, the operation control section 102 independently drives the corresponding hydraulic actuators in response to the operation of each of the operation levers 32a to 32g. Specifically, when the boom rotation / hoisting operation lever 32a is tilted forward (in the front-rear and left-right directions based on the operator operating the boom: the same applies below), the operation control section 102 drives the hoisting cylinder 16 to retract and lower the boom 13, and when the boom rotation / hoisting operation lever 32a is tilted backward, the operation control section 102 drives the hoisting cylinder 16 to extend and raise the boom 13. When the boom telescopic / flexible / extension operation lever 32b is tilted forward, the telescopic cylinder 15 is extended and the boom 13 is extended, and when the boom telescopic / flexible / extension operation lever 32b is tilted backward, the operation control section 102 drives the telescopic cylinder 15 to retract and lower the boom 13. Furthermore, when the boom swing / hoisting operation lever 32a is tilted leftward, the swing motor 14 is driven to rotate in the forward direction to swing the boom 13 counterclockwise, and when the boom swing / hoisting operation lever 32a is tilted rightward, the swing motor 14 is driven to rotate in the reverse direction to swing the boom 13 clockwise. Furthermore, when the auger operation lever 32c is tilted forward, the auger motor 21 is driven to rotate in the reverse direction to rotate the earth auger 22 in the reverse direction, and when the auger operation lever 32c is tilted backward, the auger motor 21 is driven to rotate in the forward direction to rotate the earth auger 22 in the forward direction. Furthermore, when the boom telescopic bending / extending operation lever 32b is tilted leftward, the arm cylinder 55 is driven to contract and the arm 51 is bent and extended downward relative to the tip of the boom 13, and when the boom telescopic bending / extending operation lever 32b is tilted rightward, the arm cylinder 55 is driven to extend and the arm 51 is bent and extended upward relative to the tip of the boom 13. Furthermore, when the gripper vertical swing operation lever 32d is tilted forward, the vertical swing cylinder 62 is driven to extend and the gripper 81 is swung downward (vertical swing operation), and when the gripper vertical swing operation lever 32d is tilted backward, the vertical swing cylinder 62 is driven to contract and the gripper 81 is swung upward (vertical swing operation).When the gripper horizontal swing operation lever 32e is tilted leftward, the horizontal swing cylinder 71 is extended to swing the gripper 81 to the left (horizontal swing operation), and when the gripper horizontal swing operation lever 32e is tilted rightward, the horizontal swing cylinder 71 is contracted to swing the gripper 81 to the right (horizontal swing operation). When the gripper rotation operation lever 32f is tilted forward, the gripper motor 79 is driven in the forward direction to rotate the gripper 81 clockwise, and when the gripper rotation operation lever 32f is tilted backward, the gripper motor 79 is driven in the reverse direction to rotate the gripper 81 counterclockwise. In addition, when the gripping unit opening / closing operating lever 32g is tilted forward, the gripper cylinder 99 is retracted to operate the gripping unit 81 in the closing direction (in the direction to grip the target object), and when the gripping unit opening / closing operating lever 32g is tilted backward, the gripper cylinder 99 is extended to operate the gripping unit 81 in the opening direction (in the direction to release the grip of the target object).

[0048] In addition, when the mode selection switch 33 is set to the gripper vertical operation mode and the boom rotation and hoisting operation lever 32a (in the gripper vertical operation mode, the boom rotation and hoisting operation lever 32a functions as a vertical operation lever) is operated, the operation control unit 102 calculates the position information (current position) of the gripper 81 relative to the vehicle body 2 calculated by the position calculation unit 101 and the gripper tilt information. Based on the inclination angle of the gripping part 81 with respect to the horizontal plane detected by the inclination angle detector 124, the telescopic drive of the hoisting cylinder 16, the telescopic drive of the telescopic cylinder 15, and the telescopic drive of the vertical swing cylinder 62 are linked to move the gripping part 81 (the object gripped by the gripping part 81) vertically within the hoisting plane in response to the operation of the boom rotation hoisting operation lever 32a. For example, when the boom rotation hoisting operation lever 32a is tilted forward, the retraction drive of the hoisting cylinder 16, the retraction drive of the telescopic cylinder 15, and the retraction drive of the vertical swing cylinder 62 are linked to move the gripping part 81 vertically downward, and when the boom rotation hoisting operation lever 32a is tilted backward, the extension drive of the hoisting cylinder 16, the extension drive of the telescopic cylinder 15, and the extension drive of the vertical swing cylinder 62 are linked to move the gripping part 81 vertically upward. Specifically, the vertical operation control of the gripper 81 is performed by combining control for moving the gripper 81 vertically within the hoisting surface by combining the telescopic drive of the hoisting cylinder 16 and the telescopic drive of the telescopic cylinder 15 based on the position information of the gripper 81 relative to the vehicle body 2 calculated by the position calculation unit 101, and control for maintaining the gripper 81 (rotation axis X of the gripper 81) in a horizontal state by the telescopic drive of the vertical swing cylinder 62 based on the inclination angle of the gripper 81 relative to the horizontal plane detected by the gripper inclination angle detector 126. Here, in the vertical operation control of the gripper 81, no control is performed to bend or extend the arm 51, and the arm 51 is held at the maximum bending and extending angle relative to the tip of the boom 13. In other words, in controlling the vertical operation of the gripping portion 81, when the boom 13 is operated to raise or lower while the bending and extension angle of the arm 51 is kept constant (maximum bending and extension angle), the position of the tip of the boom 13 relative to the vehicle body 2 within the hoisting surface moves in the fore-and-aft direction, and the angle of the arm 51 relative to the horizontal plane changes, causing the position of the gripping portion 81 relative to the tip of the boom 13 within the hoisting surface to also move in the fore-and-aft direction; therefore, by combining the extension and contraction operation of the boom 13 to complement the fore-and-aft movement (amount of deviation) of the tip of the boom 13 and the gripping portion 81, the gripping portion 81 is controlled to move linearly in the vertical direction.

[0049] The gripping determination unit 103 determines that the gripping portion 81 is gripping the utility pole P (the gripping portion 81 is in a state of gripping the utility pole P) when the pressure (detected pressure) detected by the gripper cylinder pressure detector 127 is equal to or greater than a predetermined set pressure.

[0050] The inclination determination unit 104 determines whether the gripping unit 81 is in a horizontal position, i.e., whether the utility pole P gripped by the gripping unit 81 is in a vertical position with respect to the ground, based on the inclination angle of the gripping unit 81 with respect to the horizontal plane detected by the gripping unit inclination angle detector 126. In this embodiment, when the inclination angle of the gripping unit 81 with respect to the horizontal plane detected by the gripping unit inclination angle detector 126 is within a predetermined angle (for example, within 5 degrees), it is determined that the utility pole P gripped by the gripping unit 81 is in a vertical position with respect to the ground.

[0051] The threshold height setting unit 105 calculates and sets a threshold height SH (see FIG. 11) as a threshold for the height above ground for restricting the operation of a part of the support mechanism of the boom 30 and the gripping device 50, based on the information (base end side length of the utility pole P) inputted in the utility pole length input device 34. This threshold height SH is a height at which the utility pole P gripped by the gripping part 81 may interfere with the ground or the vehicle (vehicle body 2) when the position and attitude (direction) of the gripping part 81 are changed in a state where the height above ground H of the gripping part 81 is equal to or lower than the threshold height SH. In this embodiment, a numerical value obtained by adding a predetermined margin (for example, 1 m) to the base end side length of the utility pole P inputted in the utility pole length input device 34 is set as the threshold height SH.

[0052] The regulating unit 106 compares the height H of the gripping unit 81 above ground calculated by the position calculating unit 101 with the threshold height SH set by the threshold height setting unit 105, on the condition that the gripping determination unit 103 has determined that the gripping unit 81 is gripping the utility pole P, and the tilt determination unit 104 has determined that the gripping unit 81 is not in a horizontal position (the utility pole P gripped by the gripping unit 81 is not in a vertical position with respect to the ground). 11(A), when the regulating unit 106 determines that the height H of the gripping unit 81 above the ground is equal to or less than the threshold height SH, the regulating unit 106 regulates the rotation of the boom 13, the bending and extending of the arm 51, and the vertical swing, horizontal swing and rotation of the gripping unit 81, regardless of the operation of the operating device 31. Here, the reason for regulating the rotation of the boom 13 when the height H of the gripping unit 81 above the ground is equal to or less than the threshold height SH is to prevent the utility pole P gripped by the gripping unit 81 at this low position from interfering with the vehicle body 2 of the host vehicle due to the rotation of the boom 13. Furthermore, the reason why the operation of the support mechanism of the gripping device 50 (the bending and stretching operation of the arm 51, the vertical swing operation, the horizontal swing operation, and the rotation operation of the gripping part 81) is restricted when the height H of the gripping part 81 above the ground is equal to or lower than the threshold height SH is to prevent the utility pole P gripped by the gripping part 81 from interfering with the ground by changing the attitude (direction) of the gripping part 81 at this low position. This operation restriction by the restriction part 106 is performed by imposing an operation restriction on the operation control part 102, such as by preventing the operation control part 102 from receiving an operation signal even if the operation to be restricted is performed, or by preventing the operation control part 102 from electromagnetically driving the electromagnetic proportional control valves V1, V5 to V8 corresponding to the actuator to be restricted even if the operation control part 102 receives an operation signal based on the operation to be restricted.

[0053] Note that even when the regulating unit 106 determines that the height H of the gripping unit 81 above the ground is equal to or less than the threshold height SH, it allows the boom 13 to be raised and lowered in response to the operation of the operation levers 32a, 32b of the operating device 31. This is intended to allow the operation of the boom 13 required to move the utility pole P gripped by the gripping unit 81 to a safe height position (a position exceeding the threshold height SH).

[0054] In addition, the reason why the condition for the above-mentioned operation restriction (first condition) is that the gripping portion 81 is gripping the utility pole P (is in a gripping state) is that if operation restriction is imposed when the gripping portion 81 is not gripping the utility pole P, it will be impossible to move (approach) the gripping portion 81 to the center of gravity of the utility pole P placed horizontally on the ground or to adjust its orientation relative to the utility pole P. The reason why the condition for the above-mentioned operation restriction (second condition) is that the utility pole P held by the gripping portion 81 is not in a vertical position relative to the ground is that, when the utility pole P held by the gripping portion 81 is already in a vertical position, there is little need to operate the support mechanism of the gripping device 50 to change the orientation of the utility pole P (rather, there is a higher need to hold the utility pole P in a vertical position), and also to prevent the operation restriction from being applied when the height H of the gripping portion 81 above ground becomes equal to or less than the threshold height SH while the gripping portion 81 is being moved vertically downward to insert the utility pole P in a vertical position held by the gripping portion 81 into a pole hole in the ground. Note that, as a modified example of the above-mentioned condition for the operation restriction (second condition), the condition may be that the mode selection switch 33 is set to the normal mode (that is, the operation restriction may not be applied when the vertical operation mode is selected).

[0055] On the other hand, when the regulating unit 106 determines that the height H of the gripping portion 81 above the ground exceeds the threshold height SH, as shown in Figure 11 (B), it allows all operations of the boom 13 and the support mechanism of the gripping device 50, i.e., the raising and lowering operation, extension and retraction operation, and rotation operation of the boom 13, the bending and extension operation of the arm 51, and the vertical swing operation, horizontal swing operation, and rotation operation of the gripping portion 81, in accordance with the operation of each of the operating levers 32a to 32f of the operating device 31.

[0056] Next, a description will be given of the pole erection work of the grip-type hole digging pole erection vehicle 1. In the following description, unless otherwise specified, it is assumed that the mode selection switch 33 is selected to the normal mode.

[0057] First, before starting the pole erection work, the worker checks the length of the utility pole P to be erected and inputs the base end side length of the utility pole P as a numerical value using the utility pole length input device 34. The threshold height setting unit 105 of the detector 100 sets the threshold height SH calculated according to the numerical value (the base end side length of the utility pole P) input by the operator.

[0058] Next, the pole erection work is started by the grip-type hole digging pole erection vehicle 1. When starting this pole erection work, first, the worker operates the operating device 31 to appropriately operate the boom 13, and also bends and extends the arm 51, and swings vertically, swings horizontally, rotates, etc., of the gripping part 81 to move the gripping part 81 to near the center of gravity of the utility pole P (the utility pole P laid horizontally on the ground at the work site), and aligns the posture of the gripping part 81 to the posture of the utility pole P, and aligns the center C of the gripping part 81 to the center of gravity of the utility pole P.

[0059] 10, the gripper opening / closing operation lever 32g is operated to operate the pair of gripping claws 82 in the closing direction (closing operation), thereby causing the gripper 81 to grip the center of gravity of the utility pole P. At this time, the grip determination unit 103 of the controller 100 determines that the gripper 81 has gripped the utility pole P (the gripper 81 is in a gripping state) by determining that the detected pressure detected by the gripper cylinder pressure detector 127 has reached a predetermined set pressure or higher. Also, the inclination determination unit 104 of the controller 100 determines that the utility pole P gripped by the gripper 81 is not in a vertical position with respect to the ground by determining that the inclination angle of the gripper 81 with respect to the horizontal plane detected by the gripper inclination angle detector 126 is equal to or greater than a predetermined angle. Here, when the gripping portion 81 grips the utility pole P placed horizontally on the ground, the height H of the gripping portion 81 above the ground is below the threshold height SH (a height position close to the ground), so the raising and lowering operations of the boom 13 are permitted, but other operations (the rotation of the boom 13, the bending and extending operation of the arm 51, the vertical swing operation, the horizontal swing operation and the rotation operation of the gripping portion 81) are restricted.

[0060] Next, as shown in Fig. 11(A), the boom rotation / hoisting operation lever 32a is operated to perform the boom 13 raising operation (hoisting and raising operation), thereby lifting the utility pole P gripped by the gripper 81 upward. Even in this state of Fig. 11(A), the height H of the gripper 81 above the ground is equal to or less than the threshold height SH, so that the rotation operation of the boom 13, the bending and extending operation of the arm 51, the vertical swing operation, the horizontal swing operation, and the rotation operation of the gripper 81 are continuously restricted. As a result, when the gripper 81 gripping the utility pole P is at a height position close to the ground (a height position close to the vehicle body 2), the rotation operation of the boom 13, the bending and extending operation of the arm 51, the vertical swing operation, the horizontal swing operation, and the rotation operation of the gripper 81 are performed, thereby preventing a situation in which the end of the utility pole P gripped by the gripper 81 interferes with the ground or the vehicle body 2 of the vehicle.

[0061] 11(B), the boom rotation / hoisting operation lever 32a is continuously operated to raise the boom 13 (hoisting / raising operation), thereby moving the utility pole P held by the gripping part 81 further upward. As a result, the height H of the gripping part 81 above the ground exceeds the threshold height SH, and the above-mentioned operation restrictions are released, and all operations such as the raising and lowering operation of the boom 13, the telescopic operation, the swiveling operation, the bending and extending operation of the arm 51, the vertical swing operation, the horizontal swing operation, and the rotation operation of the gripping part 81 are permitted. When the height H of the gripping part 81 above the ground exceeds the threshold height SH, the center C of the gripping part 81 is located higher than the base end side length of the utility pole P, so that even if the support mechanism of the gripping device 50 is operated to change the direction of the utility pole P held by the gripping part 81, there is no risk of the utility pole P interfering with the ground or the like.

[0062] Next, the operating device 31 is operated to appropriately operate the support mechanism of the boom 13 and the gripping device 50, so that the utility pole P gripped by the gripping part 81 is brought into a vertical position relative to the ground and approached to a position above the pole hole. After the utility pole P gripped by the gripping part 81 (vertical utility pole) is positioned at a position above the pole hole, the mode selection switch 33 is operated to switch from normal mode to gripping part vertical operation mode in order to move the vertical utility pole P vertically downward toward the pole hole. Mode After the selection switch 33 is switched to the gripper vertical operation mode, the lifting and telescopic operations of the boom 13 are linked with the vertical swinging operation of the gripper 81 in response to the operation of the boom rotation lifting operation lever 32a, and the gripper 81 is moved vertically downward to insert the utility pole P gripped by the gripper 81 into the pole hole. Note that even if the height H of the gripper 81 above ground becomes equal to or less than the threshold height SH while the gripper 81 is being moved vertically downward toward the pole hole, the inclination angle of the gripper 81 with respect to the horizontal plane is within a predetermined angle (i.e., the utility pole P gripped by the gripper 81 is in a vertical position with respect to the ground), the vertical downward movement of the gripper 81 is not restricted based on the judgment result of the inclination judgment unit 104.

[0063] Then, after inserting the utility pole P to the bottom of the post hole, the gap between the utility pole P and the post hole is filled with soil and sand and compacted (by backfilling with excavated soil, broken stones, etc.), so that the base end of the utility pole P can be buried in the post hole and compacted. This completes the pole installation work of installing the utility pole P in the post hole.

[0064] As described above, according to the safety device of the first embodiment, a threshold height SH is set according to the length (base end length) of the utility pole P input by the worker, and when the height H of the gripping portion 81 above the ground is below the threshold height SH, a specified operation of the support mechanism of the gripping device 50 is regulated, thereby preventing the utility pole P gripped by the gripping portion 81 from interfering with the ground due to incorrect operation by the worker (preventing the vehicle body 2 from tilting or the utility pole P from being damaged due to the utility pole P interfering with the ground), thereby making it possible to improve the safety of pole erection work.

[0065] Furthermore, in the safety device of the first embodiment, even if the length (base end length) of the utility pole P to be erected varies depending on the application or region, by setting the threshold height SH according to the length (base end length) of the utility pole P to be erected, it is possible to reliably prevent the utility pole P held by the gripping portion 81 from interfering with the ground regardless of the length of the utility pole P to be erected, thereby making it possible to further improve the safety of the pole erection work.

[0066] In addition, in the safety device of the first embodiment, when the height H of the gripping portion 81 above the ground is equal to or less than the threshold height SH, in addition to the specified operation of the support mechanism of the gripping device 50, the rotation operation of the boom 13 is also regulated, thereby preventing the utility pole P gripped by the gripping portion 81 from interfering with the vehicle body 2 due to erroneous operation by the worker.

[0067] Furthermore, in the safety device of the first embodiment, when the height H of the gripping portion 81 above the ground is equal to or less than the threshold height SH, the specified operation of the support mechanism of the gripping device 50 is regulated on the condition that the gripping portion 81 is gripping the utility pole P (is in a gripping state), thereby making it possible to prevent a situation in which, when the gripping portion 81 is to grip the utility pole P, it is unable to approach the utility pole P that is laid horizontally on the ground (the gripping portion 81 is unable to grip the utility pole P).

[0068] In addition, in the safety device of the first embodiment, when the height H of the gripping portion 81 above the ground is equal to or less than the threshold height SH, the inclination angle of the gripping portion 81 relative to the horizontal plane exceeds a predetermined angle (the utility pole P gripped by the gripping portion 81 is not in a vertical position relative to the ground), thereby restricting a predetermined operation of the support mechanism of the gripping device 50, thereby making it possible to prevent operation restriction from being applied while the gripping portion 81 is being moved downward and the utility pole P in a vertical position gripped by the gripping portion 81 is being inserted into a post hole in the ground.

[0069] [First Modification of the First Embodiment] Next, a safety device according to a first modified example of the first embodiment will be described with reference to Fig. 12. In the following description, the same components as those in the first embodiment (or components having the same functions) are denoted by the same reference numerals, and duplicated explanations are omitted. Differences from the first embodiment will be mainly described. The explanation will focus on the parts.

[0070] 12, the safety device according to the first modified example is mainly composed of a utility pole length input device 34, an excavation position setting switch 35, an automatic pole erection switch 36, a boom hoisting angle detector 120, a boom extension amount detector 121, a boom rotation angle detector 122, an arm bending / extending angle detector 123, a gripper vertical swing angle detector 124, a gripper horizontal swing angle detector 125, a gripper tilt angle detector 126, a gripper cylinder pressure detector 127, and a controller 100. The safety device according to the first modified example is equipped with an automatic pole erection function in addition to the above-mentioned function of preventing interference with the utility pole P, which will be described in detail later.

[0071] The excavation position setting switch 35 is provided on the operating device 31. This excavation position setting switch 35 is operated to set and store in the controller 100 the position of the tip of the boom 13 (the excavation position of the earth auger 22) when the earth auger 22 is performing an excavation operation as information for specifying the excavation position of the earth auger 22 (the position of the post hole). In this modified example, when the operator operates the excavation position setting switch 35 during the excavation operation of the earth auger 22, position information of the tip of the boom 13 detected at that time (position information of the earth auger 22) is stored in an excavation position memory unit 107 of the controller 100 described later.

[0072] The automatic pole erection switch 36 is operated to automatically erect the utility pole P held by the holding portion 81 into the pole erection hole (to execute automatic pole erection). In this modified example, the automatic pole erection work described below is started when the automatic pole erection switch 36 is operated.

[0073] The controller 100 includes a position calculation unit 101 , an operation control unit 102 , a grip determination unit 103 , an inclination determination unit 104 , a threshold height setting unit 105 , a regulation unit 106 , and an excavation position storage unit 107 .

[0074] When the excavation position memory unit 107 receives an operation signal from the excavation position setting switch 35, it stores the boom hoisting angle (referred to as the "detected hoisting angle"), extension amount (referred to as the "detected extension amount"), and rotation angle (referred to as the "detected rotation angle") of the boom 13 detected by each detector 120-122 at that time.

[0075] When the operation control unit 102 receives an operation signal from the automatic pole erection switch 36, it starts automatic pole erection for the utility pole P held by the holding unit 81. The details of this automatic pole erection will be described later.

[0076] Next, the pole erection work (including automatic pole erection) in the first modified example will be described. In the first modified example, for the sake of simplicity, it is assumed that the auger device 20 has already finished excavating the pole hole, and the position data during the excavation operation (detected elevation angle, detected extension amount, detected rotation angle) is stored in the excavation position memory unit 107. In addition, unless otherwise specified in the following description, it is assumed that the mode selection switch 33 is selected to the normal mode.

[0077] First, similarly to the above-described first embodiment, before starting pole erection work, the base end side length of the utility pole P to be erected is input on the setting input screen of the utility pole length input device 34. As a result, the threshold height setting unit 105 of the controller 100 sets the threshold height SH calculated according to the base end side length of the utility pole P input by the worker.

[0078] As in the first embodiment, the worker operates the operating device 31 to appropriately operate the boom 13, and also to bend and extend the arm 51, and to vertically swing, horizontally swing, and rotate the gripping portion 81, thereby attaching the gripping portion 81 to a utility pole P (which is placed horizontally on the ground at the work site). The gripping portion 81 is moved to the vicinity of the center of gravity of the utility pole P, and the posture of the gripping portion 81 is adjusted to match the posture of the utility pole P, and the center C of the gripping portion 81 is aligned with the center of gravity of the utility pole P.

[0079] Next, similarly to the first embodiment, the gripping portion opening / closing operation lever 32g is operated to operate the pair of gripping claws 82 in the closing direction (closing operation), thereby causing the gripping portion 81 to grip the center of gravity of the utility pole P.

[0080] Next, the worker operates the automatic pole erection switch 36 to start automatic pole erection of the utility pole P. First, when the operation control unit 102 receives an operation signal from the automatic pole erection switch 36, it performs an elevation operation (raising and lowering operation) of the boom 13 to raise the gripping unit 81 gripping the utility pole P until the height H of the gripping unit 81 above the ground calculated by the position calculation unit 101 exceeds the threshold height SH set by the threshold height setting unit 105. In a state in which the height H of the gripping unit 81 above the ground exceeds the threshold height SH, the utility pole P gripped by the gripping unit 81 will be at a height position that does not interfere with the ground even if the bending and extending operation of the arm 51, the vertical swing operation, horizontal swing operation, rotation operation, etc. of the gripping unit 81 are performed in the subsequent operation control.

[0081] Next, based on the detection information from the gripper tilt angle detector 126, the operation control unit 102 extends and retracts the vertical swing cylinder 62 to correct the forward / rearward tilt of the gripper 81, and rotates the gripper motor 79 to correct the left / right tilt of the gripper 81, thereby bringing the gripper 81 into a horizontal position. This allows the utility pole P gripped by the gripper 81 to be in a vertical position relative to the ground.

[0082] Next, the operation control unit 102 rotates the boom 13 until the rotation angle of the boom 13 matches the detected rotation angle stored in the excavation position memory unit 107. Furthermore, the operation control unit 102 moves the gripper 81 (the utility pole P gripped by the gripper 81) horizontally to a position above the pole hole by linking the hoisting operation and the telescopic operation of the boom 13, while taking into account the relationship between the detected hoisting angle and the detected extension amount stored in the excavation position memory unit 107, so that, at the rotation position of the boom 13, the distance (working radius) from the rotation center to the gripper 81 becomes the same as the distance (working radius) from the rotation center to the tip of the boom 13 (earth auger 22) during the previous excavation operation.

[0083] Next, the operation control unit 102 moves the gripper 81 vertically downward by interlocking the raising and lowering operation of the boom 13 with the vertical swinging operation of the gripper 81, thereby inserting the utility pole P held by the gripper 81 to the bottom of the post hole. After the utility pole P has been inserted to the bottom of the post hole in this manner, the worker can fill the gap between the utility pole P and the post hole with soil and sand to harden it (by backfilling the excavated soil, broken stones, etc.), thereby burying and compacting the base end of the utility pole P in the post hole. This completes the pole erection work (automatic pole erection work) of installing the utility pole P in the post hole.

[0084] As described above, according to the safety device of the first modified example of the first embodiment, a threshold height SH is set according to the length (base end length) of the utility pole P input by the worker, and the height of the gripping portion 81 is controlled to correspond to the actual length (base end length) of the utility pole P as a control during automatic pole erection. This makes it possible to prevent the utility pole P gripped by the gripping portion 81 from interfering with the ground, etc. during execution of this automatic pole erection, thereby improving the safety and work efficiency of the pole erection work.

[0085] [Second Modification of the First Embodiment] Next, a safety device according to a second modified example of the first embodiment will be described with reference to Figures 13 and 14. In the following description, the same components as those in the first embodiment (or components having the same functions) are denoted by the same reference numerals, and duplicated description will be omitted. The following description will mainly focus on the parts that differ from the first embodiment.

[0086] In this second modified example, the utility pole P to be erected is configured as a split pole BP consisting of a lower pole BP1 and an upper pole BP2, as shown in Fig. 13. This split pole BP is installed on the ground as a single utility pole P by first installing the lower pole BP1 on the ground, and then connecting the lower end of the upper pole BP2 to the upper end of the lower pole BP1 (for example, by fastening brim-shaped flanges provided on the upper end of the lower pole BP1 and the lower end of the upper pole BP2 with bolts and nuts).

[0087] 14, the safety device according to the second modified example is mainly composed of a pole length input device 34, a pole position setting switch 37, an automatic position alignment switch 38, a boom hoisting angle detector 120, a boom extension amount detector 121, a boom rotation angle detector 122, an arm bending / extending angle detector 123, a gripper vertical swing angle detector 124, a gripper horizontal swing angle detector 125, a gripper inclination angle detector 126, a gripper cylinder pressure detector 127, and a controller 100. Note that, as will be described in detail later, the safety device according to the second modified example is equipped with a position alignment function for the divided poles BP (lower pole BP1 and upper pole BP2) in addition to the above-mentioned function of preventing interference with the pole P.

[0088] As shown in Fig. 13(A), the pole length input device 34 inputs numerical values ​​including the height Ha of the lower pole BP1 above ground and the base end length Hb of the upper pole BP2 as length information of the divided pole BP. "The height Ha of the lower pole BP1 above ground" is the height from the ground to the upper end of the lower pole BP1 when the lower pole BP1 is installed on the ground (pole installation hole). "The base end length Hb of the upper pole BP2" is the length from the center of gravity of the upper pole BP2 to the base end position.

[0089] The pole erection position setting switch 37 is provided on the above-mentioned operating device 31. This pole erection position setting switch 37 is operated to set and store the position of the gripping part 81 (i.e., the position of the lower pole BP1) when the pole erection work of the lower pole BP1 is being performed as information for specifying the position of the lower pole BP1. In this modified example, when the worker operates the pole erection position setting switch 37 during the pole erection work of the lower pole BP1, the position of the gripping part 81 (the position of the lower pole BP1) calculated by the position calculation unit 101 at that time point is stored in the pole erection position storage unit 108 of the controller 100 described later.

[0090] The automatic alignment switch 38 is operated to automatically align the lower end of the upper pole BP2 held by the gripping portion 81 with the upper end of the lower pole BP1 installed on the ground.

[0091] The controller 100 includes a position calculation unit 101, an operation control unit 102, a gripping determination unit 103, an inclination determination unit 104, a threshold height setting unit 105, a regulating unit 106, a pole position memory unit 108, and an alignment position setting unit 109.

[0092] When the pole-setting position storage unit 108 receives an operation signal from the pole-setting position setting switch 37, it stores the position of the gripping part 81 calculated by the position calculation unit 101 at that time (the position in the above-mentioned XYZ coordinate system).

[0093] The alignment position setting unit 109 calculates and stores the position of the gripping unit 81 (referred to as the "alignment position") for aligning the upper column BP2 gripped by the gripping unit 81 with respect to the existing lower column BP1. As shown in FIG. 13(B), the alignment position of the gripping unit 81 is set to a position where the central axis (X-coordinate position, Y-coordinate position) of the upper column BP2 and the central axis (X-coordinate position, Y-coordinate position) of the lower column BP1 coincide with each other, and the height above ground of the lower end of the upper column BP2 is a predetermined distance (a distance corresponding to a margin M described later) higher than the height above ground of the upper end of the lower column BP1. Specifically, the alignment position in the X-axis direction of the gripping unit 81 is the X-coordinate position of the gripping unit 81 stored in the column erection position storage unit 108 (the X-coordinate position of the gripping unit 81 when the column erection work of the lower column BP1 is being performed). The alignment position in the Y-axis direction of the gripping unit 81 is set to a position where the central axis (X-coordinate position, Y-coordinate position) of the upper column BP2 and the central axis (X-coordinate position, Y-coordinate position) of the lower column BP1 coincide with each other, and the height above ground of the lower end of the upper column BP2 is a predetermined distance (a distance corresponding to a margin M described later) higher than the height above ground of the upper end of the lower column BP1. The Y coordinate position of the gripping part 81 obtained by adding the height Ha of the lower pole BP1 above ground and the base end side length Hb of the upper pole BP2 inputted in the utility pole length input device 34, and adding a predetermined margin (predetermined distance) M to the sum.

[0094] When the operation control unit 102 receives an operation signal from the automatic alignment switch 38, it executes automatic alignment of the upper pillar BP2 held by the gripping unit 81 with respect to the existing lower pillar BP1, based on the alignment position (XYZ coordinate position) of the gripping unit 81 stored in the alignment position setting unit 109. The details of this automatic alignment of the divided pillar BP will be described later.

[0095] Next, the automatic alignment of the divided pillar BP in the second modified example will be explained. In this second modified example, for the sake of simplicity, it is assumed that the erection work of the lower pillar BP1 has already been completed (the lower pillar BP1 has been installed on the ground) and the position data of the lower pillar BP1 during the erection work is stored in the erection position memory unit 108. In addition, unless otherwise specified in the following explanation, it is assumed that the mode selection switch 33 is selected to the normal mode.

[0096] First, before starting the pole erection work (automatic alignment) of the upper pole BP2, the height Ha of the existing lower pole BP1 above ground and the base end side length Hb of the upper pole BP2 are input on the setting input screen of the utility pole length input device 34. Thereby, the threshold height setting unit 105 of the controller 100 sets the threshold height SH calculated according to the input information (base end side length Hb of the lower pole BP2) input in the utility pole length input device 34. In addition, the alignment position setting unit 109 calculates and stores the alignment position (XYZ coordinate position) of the gripper 81 based on the position data stored in the pole erection position storage unit 108 and the input information (height Ha of the lower pole BP1 above ground, base end side length Hb of the upper pole BP2) input in the utility pole length input device 34.

[0097] Next, to start the erection work of the upper column BP2, the worker operates the operating device 31 to operate the boom 13 appropriately, and also bends and extends the arm 51, and swings the gripping part 81 vertically, horizontally, and rotates it, thereby moving the gripping part 81 to near the center of gravity of the upper column BP2 (upper column BP2 laid horizontally on the ground at the work site), aligning the posture of the gripping part 81 to the posture of the upper column BP2, and aligning the center C of the gripping part 81 with the center of gravity of the upper column BP2.

[0098] Next, the gripping portion opening / closing operation lever 32g is operated to operate the pair of gripping claws 82 in the closing direction (closing operation), thereby causing the gripping portion 81 to grip the center of gravity position of the upper pillar BP2.

[0099] Next, the worker operates the automatic alignment switch 38 to start automatic alignment of the upper pillar BP2. First, when the operation control unit 102 receives an operation signal from the automatic alignment switch 38, it operates the boom 13 to raise (raise and lower) the gripper 81 gripping the upper pillar BP2 until the ground height H of the gripper 81 calculated by the position calculation unit 101 exceeds the threshold height SH set by the threshold height setting unit 105. In a state in which the ground height H of the gripper 81 exceeds the threshold height SH, the upper pillar BP2 gripped by the gripper 81 will be at a height position that does not interfere with the ground even if the arm 51 is bent and extended, the gripper 81 is swung vertically, swung horizontally, or rotated in the subsequent operation control.

[0100] Next, the operation control unit 102 corrects the forward / rearward tilt of the gripper 81 by extending and retracting the vertical swing cylinder 62 based on the detection information from the gripper tilt angle detector 126, and also corrects the left / right tilt of the gripper 81 by rotating the gripper motor 79, thereby bringing the gripper 81 into a horizontal position. This allows the upper pillar BP2 gripped by the gripper 81 to be in a vertical position relative to the ground.

[0101] Next, the operation control unit 102 operates the support mechanism of the boom 13 and the gripping device 50 based on the position data (the alignment position of the gripping unit 81 in the X-axis direction, the Y-axis direction, and the Z-axis direction) stored in the alignment position setting unit 109, and moves the gripping unit 81 gripping the upper column BP2 to the alignment position with respect to the lower column BP1. When the gripping unit 81 reaches the alignment position, the central axis (X-coordinate position, Y-coordinate position) of the upper column BP2 gripped by the gripping unit 81 coincides with the central axis (X-coordinate position, Y-coordinate position) of the existing lower column BP1, and the lower end of the upper column BP2 is positioned at a position higher than the ground height Ha of the upper end of the lower column BP1 by a predetermined distance (the distance of the margin M). As a result, the upper column BP2 gripped by the gripping unit 81 is automatically aligned with the existing lower column BP1.

[0102] After the upper column BP2 is automatically aligned with the lower column BP1 in this way, the flanges of the upper column BP2 and the lower column BP1 are aligned in the circumferential direction (aligning the bolt holes of each other) and the flanges of the upper column BP2 and the lower column BP1 are abutted against each other in the vertical direction. Then, by fastening the flanges of the upper column BP2 and the lower column BP1 with bolts and nuts, the upper column BP2 and the lower column BP1 are installed on the ground as a single utility pole P that is integrally connected.

[0103] As described above, according to the safety device of the second modified example of the first embodiment, a threshold height SH is set according to the length (base end length) of the upper column BP2 input by the worker, and the height of the holding portion 81 is controlled to correspond to the actual length (base end length) of the upper column BP2 as control for automatic alignment of the split column BP. This prevents the upper column BP2 held by the holding portion 81 from interfering with the ground, etc. during the execution of this automatic alignment, while automatically and accurately aligning the lower end of the upper column BP2 with the upper end of the existing lower column BP1, thereby making it possible to improve the safety and work efficiency of the alignment work (pillar erection work) of the split column BP.

[0104] [Second embodiment] Next, a safety device according to a second embodiment of the present invention will be described with reference to Figures 15 and 16. In the following description, the same components (or components having the same functions) as those in the first embodiment will be denoted by the same reference numerals, and duplicated description will be omitted. The following description will mainly focus on the parts that differ from the first embodiment.

[0105] As shown in FIG. 15 , the safety device of the second embodiment is mainly composed of a boom hoisting angle detector 120, a boom extension amount detector 121, a boom rotation angle detector 122, an arm bending / extending angle detector 123, a gripper vertical swing angle detector 124, a gripper horizontal swing angle detector 125, a gripper inclination angle detector 126, a gripper cylinder pressure detector 127, a pole length detection device 130, and a controller 100.

[0106] As shown in FIG. 16, the utility pole length detection device 130 is configured to include a transmitting device 140 provided on the utility pole P to be erected, and a receiving device 150 provided on the swivel base 12.

[0107] The transmitter 140 has a first beacon transmitter 141 attached to the center of gravity of the utility pole P in the central axis direction, and a second beacon transmitter 142 attached to the base end position in the central axis direction of the utility pole P. Both beacon transmitters 141, 142 are arranged so that a line segment connecting the first beacon transmitter 141 and the second beacon transmitter 142 is approximately parallel to the central axis of the utility pole P. In other words, the distance between the first beacon transmitter 141 and the second beacon transmitter 142 is approximately equal to the length between the center of gravity of the utility pole P and the base end position (the base end side length of the utility pole P).

[0108] Each of the beacon transmitters 141 and 142 is, for example, a small transmission module incorporating a transmission circuit and a battery. The beacon transmitters 141, 142 transmit beacon signals in a frequency band based on a short-range wireless communication standard such as IEEE 802.11b (registered trademark) or ZigBee (registered trademark) as radio signals at predetermined time intervals. The beacon signals include unique identification information (beacon ID) for identifying the respective beacon transmitters 141, 142. Each of the beacon transmitters 141, 142 may be attached to the outer periphery of the utility pole P or may be attached inside the utility pole P (hollow portion). The beacon transmitters 141, 142 can be attached in any suitable manner, such as by screwing the beacon transmitters 141, 142 into place using the screw holes in a center of gravity marker member (see, for example, Japanese Utility Model Application Publication No. 55-172559) provided at the center of gravity of the utility pole P, by wrapping a belt member (see, for example, Japanese Patent Application Publication No. 2007-208901) to which the beacon transmitters 141, 142 are attached around the outer periphery of the utility pole P and fixing it, by gluing the beacon transmitters 141, 142 to the utility pole P, by removably fixing the beacon transmitters 141, 142 to the utility pole P using hook-and-loop fastener or the like, or by burying the beacon transmitters 141, 142 inside the utility pole P.

[0109] The receiving device 150 has three beacon receivers (a first beacon receiver 151, a second beacon receiver 152, and a third beacon receiver 153) attached to the turntable 12a of the rotating base 12. The beacon receivers 151 to 153 are arranged at equal intervals (120 degree intervals) in the circumferential direction with respect to the center of rotation of the turntable 12a. The beacon receivers 151 to 153 may be arranged at other positions on the vehicle body 2, for example, in the operator's seat 30, as long as their positions with respect to the center of rotation can be specified. Each of the beacon receivers 151 to 153 is provided with a radio wave sensor (not shown) that detects radio wave intensity (received radio wave intensity) when a beacon signal is received from each of the beacon transmitters 141 and 142. Each beacon receiver 151-153 receives a beacon signal transmitted from the beacon transmitters 141, 142, and detects the radio wave strength (received radio wave strength) of the beacon signal to obtain the beacon ID attached to the beacon signal and radio wave strength information (received radio wave strength) when the beacon signal was received, and transmits this obtained information to the controller 100 as beacon information.

[0110] The controller 100 includes a position calculation unit 101, an operation control unit 102, a gripping determination unit 103, a tilt determination unit 104, a threshold height setting unit 105, a regulation unit 106, a distance calculation unit 161, a transmission position calculation unit 162, and a utility pole length calculation unit 163.

[0111] The distance calculation unit 161 calculates the distance (separation distance) between each of the beacon transmitters 141, 142 and each of the beacon receivers 151-153 based on the beacon information transmitted from the three beacon receivers 151-153. Here, the received radio wave intensity (radio wave level) received by each of the beacon receivers 151-153 has a property of being inversely proportional to the square of the distance from the beacon transmitter 141, 142 that is the source of the radio wave (the closer the distance to the source, the stronger the radio wave, and the farther the distance from the source, the weaker the radio wave). In this embodiment, by utilizing this property of the received radio wave intensity, the distance between each of the beacon transmitters 141, 142 and each of the beacon receivers 151-153 is calculated based on the received radio wave intensity from each of the beacon transmitters 141, 142 received by each of the beacon receivers 151-153. Specifically, the distance calculation unit 161 calculates the distance between the first beacon transmitter 141 and the first beacon receiver 151 based on the strength of the radio wave received from the first beacon transmitter 141 at the first beacon receiver 151, and calculates the distance between the second beacon transmitter 142 and the first beacon receiver 151 based on the strength of the radio wave received from the second beacon transmitter 142 at the first beacon receiver 151. The distance calculation unit 161 also calculates the distance between the first beacon transmitter 141 and the second beacon receiver 152 based on the strength of the radio wave received from the first beacon transmitter 141 at the second beacon receiver 152, and calculates the distance between the second beacon transmitter 142 and the second beacon receiver 152 based on the strength of the radio wave received from the second beacon transmitter 142 at the second beacon receiver 152. The distance calculation unit 161 also calculates the distance from the third beacon received by the third beacon receiver 153. Based on the received radio wave strength from the first beacon transmitter 141, the distance between the first beacon transmitter 141 and the third beacon receiver 153 is calculated, and based on the received radio wave strength from the second beacon transmitter 142 received at the third beacon receiver 153, the distance between the second beacon transmitter 142 and the third beacon receiver 153 is calculated.

[0112] The transmission position calculation unit 162 calculates the position (relative position) of each of the beacon transmitters 141, 142 with respect to the turning center based on the distance information (the distance between each of the beacon transmitters 141, 142 and each of the beacon receivers 151 to 153) calculated in the distance calculation unit 161. Specifically, the transmission position calculation unit 162 calculates the position of the first beacon transmitter 141 with respect to the turning center based on the distance between the first beacon transmitter 141 and the first beacon receiver 151, the distance between the first beacon transmitter 141 and the second beacon receiver 152, and the distance between the first beacon transmitter 141 and the third beacon receiver 153 as the distance information of the first beacon transmitter 141 calculated in the distance calculation unit 161. Similarly, the transmission position calculation unit 162 calculates the position (relative position) of the second beacon transmitter 142 with respect to the turning center based on the distance between the second beacon transmitter 142 and the first beacon receiver 151, the distance between the second beacon transmitter 142 and the second beacon receiver 152, and the distance between the second beacon transmitter 142 and the third beacon receiver 153 as the distance information of the second beacon transmitter 142 calculated in the distance calculation unit 161. Note that, since the positions of the three beacon receivers 151 to 153 with respect to the turning center are pre-stored as known information in the transmission position calculation unit 162, the distance calculation unit 161 calculates the distances between each of the beacon transmitters 141, 142 and the three beacon receivers 151 to 153, respectively, and thus the positions (relative positions) of each of the beacon transmitters 141, 142 with respect to the turning center can be calculated using the principle of so-called three-point positioning.

[0113] The utility pole length calculation unit 163 calculates the distance between the first beacon transmitter 141 and the second beacon transmitter 142 based on the position information of the first beacon transmitter 141 and the second beacon transmitter 142 calculated by the transmission position calculation unit 162, and calculates this as the base end side length of the utility pole P. That is, in this embodiment, the position of the first beacon transmitter 141 corresponds to the center of gravity position in the central axis direction of the utility pole P, and the position of the second beacon transmitter 142 corresponds to the base end position in the central axis direction of the utility pole P, so that the distance between the first beacon transmitter 141 and the second beacon transmitter 142 can be calculated as the distance between the center of gravity position and the base end position of the utility pole P (the base end side length of the utility pole P).

[0114] The threshold height setting unit 105 calculates and sets a height threshold (threshold height SH) for restricting the operation of a part of the support mechanism of the boom 30 and the gripping device 50 based on the base end side length of the utility pole P calculated by the utility pole length calculation unit 163. As in the first embodiment, the threshold height setting unit 105 sets a numerical value obtained by adding a predetermined margin (for example, 1 m) to the base end side length of the utility pole P calculated by the utility pole length calculation unit 163 as the threshold height SH.

[0115] As described above, the safety device of the second embodiment can provide the same effects as the safety device of the first embodiment described above. In addition, the safety device of the second embodiment automatically detects the length (base end length) of the utility pole P to set the threshold height SH, which reduces the burden on workers at the work site and ensures that an appropriate threshold height SH can be set for each type of utility pole P, making it possible to further improve the safety of pole erection work.

[0116] [Third embodiment] Next, a safety device according to a third embodiment of the present invention will be described with reference to Fig. 17. In the following description, the same components (or components having the same functions) as those in the first embodiment will be denoted by the same reference numerals, and duplicated explanations will be omitted. The following description will mainly focus on the parts that differ from the first embodiment.

[0117] As shown in FIG. 17, the safety device of the third embodiment is mainly composed of a threshold height input device 39, a boom hoisting angle detector 120, a boom extension amount detector 121, a boom rotation angle detector 122, an arm bending / extending angle detector 123, a gripper vertical swing angle detector 124, a gripper horizontal swing angle detector 125, a gripper inclination angle detector 126, a gripper cylinder pressure detector 127, and a controller 100.

[0118] The threshold height input device 39 is provided on the operation device 31. The threshold height input device 39 is configured, for example, by a touch panel type liquid crystal display, as in the case of the utility pole length input device 34 of the first embodiment, and is configured to be able to display a predetermined setting input screen. The setting input screen is a screen for setting and inputting the threshold height SH used in the current pole erection work as a numerical value. This setting input screen displays a numeric keypad and display buttons (for example, buttons such as △ and ▽) that instruct the user to increase or decrease the numerical value, thereby enabling numerical input via the touch panel (i.e., the worker can input the desired threshold height SH as a numerical value). Therefore, in this embodiment, for example, the threshold height SH can be set according to the skill level of the worker, and the threshold height SH can be set to a relatively low position for a highly skilled worker, and the threshold height SH can be set to a relatively high position for a less skilled worker. The numerical information of the threshold height SH inputted in this threshold height input device 39 is outputted to the controller 100.

[0119] The controller 100 includes a position calculation unit 101, an operation control unit 102, a grip determination unit 103, a tilt determination unit 104, a threshold height setting unit 105, and a regulation unit 106, similarly to the first embodiment.

[0120] The threshold height setting unit 105 sets a threshold height SH for restricting the operation of a part of the support mechanism of the boom 13 and the gripping device 50, based on the input information of the threshold height input device 39. In this embodiment, for example, when a value of "3" is input on the setting input screen of the threshold height input device 39, the threshold height SH is set at a height of "3 m" from the ground.

[0121] As described above, the safety device of the third embodiment can provide the same effects as the safety device of the first embodiment. Moreover, the safety device of the third embodiment can directly set a desired threshold height SH according to the skill level of the worker, so that it is possible to achieve both safety and work efficiency in pole erection work.

[0122] The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the gist of the present invention.

[0123] In the above embodiment, when the height H of the gripper 81 above the ground is equal to or lower than the threshold height SH, the rotation operation of the boom 13, the bending and extending operation of the arm 51, the vertical swing operation, the horizontal swing operation, and the rotation operation of the gripper 81 are restricted. However, the present invention is not limited to this configuration, and the operations to be restricted may be changed as appropriate. For example, when the height H of the gripper 81 above the ground is equal to or lower than the threshold height SH, all operations of the boom 30 (raising and lowering operation, telescopic operation, and swing operation) may not be restricted, and all operations of the support mechanism of the gripper 50 (bending and extending operation of the arm 51, the vertical swing operation, horizontal swing operation, and rotation operation of the gripper 81) may be restricted. Also, when the height H of the gripper 81 above the ground is equal to or lower than the threshold height SH, some operations of the support mechanism of the gripper 50 (for example, bending and extending operation of the arm 51 and the rotation operation of the gripper 81) may be restricted, and other operations (for example, the vertical swing operation and horizontal swing operation of the gripper 81) may not be restricted.

[0124] In the above embodiment, the base end side length of the utility pole P (the length from the center of gravity position to the base end position) is input or detected, but the present invention is not limited to this configuration. The controller 100 may be configured to input or detect the length (length from the top end position to the base end position) of the utility pole P. In this case, the threshold height setting unit 105 calculates (estimates) the base end side length of the utility pole P based on the input or detected overall length of the utility pole P, and sets the threshold height SH. This threshold height SH may be set and stored in advance in the storage unit of the controller 100. The controller 100 may be configured to set and store a plurality of types of threshold heights SH in advance, allowing the operator to select a desired threshold height SH.

[0125] In addition, in the above embodiment, the operating device 31 is provided on the operating seat 30 on the vehicle body 2, but this configuration is not limited to this, and for example, the operating device 31 may be configured as a wired or wireless remote control operating device (portable operating device).

[0126] In addition, in the above embodiment, a PTO-driven gripper type pole hole digger vehicle is exemplified, in which engine power is extracted by a PTO mechanism (power take-off mechanism) to drive a hydraulic pump. However, the present invention is not limited to this configuration, and may also be an electrically powered (battery-powered) gripper type pole hole digger vehicle, or a hybrid type gripper type pole hole digger vehicle that has both and can selectively switch between power sources. [Explanation of symbols]

[0127] 1 Grasping type hole digging pole erecting vehicle (gripping type pole erecting vehicle) 2. Body 12 Swivel table 13. Boom 31 Operating device 34 Utility pole length input device (input device) 39 Threshold height input device (input device) 50 Gripping device 51 Arm (support mechanism) 60 First joint member (support mechanism) 70 Second joint member (support mechanism) 81 Gripping part 100 Controller 101 Position calculation unit (height calculation unit) 102 Operation control section 103 Grip determination section 104 Inclination determination section 105 Threshold height setting unit 106 Regulatory Department 126 Grip tilt angle detector (Grip tilt angle detector) 130 Utility pole length detector (length detector) 140 Transmitting device (transmitting unit) 141 First beacon transmitter (first radio transmitter) 142 Second beacon transmitter (second radio wave transmitter) 150 Receiving device (receiving section) 151 First Beacon Receiver 152 Second Beacon Receiver 153 3rd Beacon Receiver 163 Pole Length Calculation Unit P Utility pole (pillar-shaped object)

Claims

1. A drivable vehicle body; A boom provided on the vehicle body so as to be capable of rising, falling, extending and rotating; A gripping portion provided at a tip of the boom for gripping a columnar object; a support mechanism provided between the tip of the boom and the gripping part, the support mechanism changing a position and a posture of the gripping part relative to the tip of the boom; A height detection unit that detects the height of the gripping portion; an operating device for operating the boom and the support mechanism; an operation control unit that operates the boom and the support mechanism in response to an operation of the operation device; A safety device for a gripping type pole erection vehicle, characterized in that it is equipped with a regulating unit that regulates a specified operation of the support mechanism when the height of the gripping portion detected by the height detection unit is below a predetermined threshold height when the gripping portion is gripping the pole-shaped object.

2. an input device for inputting information regarding the length of the pillar; The safety device of the gripping-type pole erection vehicle described in claim 1, characterized in that it is equipped with a threshold height setting unit that sets the threshold height based on information regarding the length of the pole inputted in the input device.

3. a length detection device for detecting information regarding the length of the column; A safety device for a gripping-type pole erection vehicle as described in claim 1, characterized in that it is equipped with a threshold height setting unit that sets the threshold height based on information regarding the length of the pole detected by the length detection device.

4. The length detection device includes a transmitter provided on the pillar and a receiver provided on the vehicle body for receiving radio waves from the transmitter, the transmitting unit includes a first radio wave transmitter provided at a center of gravity of the columnar object in a central axis direction, and a second radio wave transmitter provided at an end portion of the columnar object in the central axis direction, a transmission position calculation unit that calculates positions of the first radio wave transmitter and the second radio wave transmitter with respect to the vehicle body based on reception strengths of radio wave signals from the first radio wave transmitter and the second radio wave transmitter received by the receiving unit; The safety device of the gripping-type pole erection vehicle described in claim 3, characterized in that it is further characterized by comprising a pole length calculation unit that calculates the length from the center of gravity position in the central axial direction of the pole to an end position as information regarding the length of the pole-shaped object based on the positions of the first radio wave transmitter and the second radio wave transmitter relative to the vehicle body calculated by the transmission position calculation unit.

5. an input device for inputting information regarding the threshold height; A safety device for a pole-handling vehicle as described in claim 1, characterized in that it is provided with a threshold height setting unit that sets the threshold height based on information regarding the threshold height inputted in the input device.

6. a gripping determination unit that determines whether the gripping unit has gripped the columnar object, A safety device for a gripping-type pole erection vehicle as described in any one of claims 1 to 5, characterized in that the regulating unit regulates the specified operation when the gripping determination unit determines that the gripping unit has gripped the pole-shaped object and when the height of the gripping unit detected by the height detection unit is below the threshold height.

7. a gripping portion inclination angle detection unit that detects an inclination angle of the gripping portion with respect to a horizontal plane, The regulating portion is configured to regulate the tilt angle of the grip portion with respect to the horizontal plane of the grip portion detected by the grip portion tilt angle detection portion. A safety device for a gripping-type pole erection vehicle as described in claim 6, characterized in that the specified operation is regulated when the inclination angle of the gripping portion exceeds a predetermined angle and the height of the gripping portion detected by the height detection unit is below the threshold height.

Images