Control device for gripping type excavation posting vehicle

Abstract

To provide a control device for a gripping type excavation posting vehicle which can detect that a columnar object gripped by a gripping part reaches a hole bottom of a pole construction hole.SOLUTION: A gripping type excavation posting vehicle includes a boom provided on a vehicle body, a gripping part for gripping a columnar object, a support mechanism for changing the attitude of the gripping part to the tip of the boom, a gripping part load detector 125 for detecting a load acting on the gripping part in the state where the gripping part grips the columnar object, an operation control part 102 for controlling operations of the boom, the gripping part and the support mechanism according to the operation of an operation device 31, and a load determination part 106 for regulating downward movement of the gripping part, in the case where the load detected by the gripping part load detector 125 is reduced to be equal to or lower than a prescribed threshold load, when the gripping part gripping the columnar object is moved downward by operating the boom and the support mechanism.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a control device for a gripping type pole-digging and column-building vehicle equipped with a gripping device for gripping a columnar object, for example.

Background Art

[0002] As a pole-digging and column-building vehicle, which is one type of work vehicle, there is known a gripping type pole-digging and column-building vehicle including a swivel base provided rotatably on a vehicle body, a boom provided on the swivel base so as to be capable of lifting and lowering and extending and contracting, an auger device attached to the boom for excavating a column-building hole for driving a utility pole, and a gripping device provided at the tip of the boom for gripping a columnar object such as a utility pole (see, for example, Patent Document 1). When excavating a column-building hole in the ground using such a gripping type pole-digging and column-building 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 excavation position, whereby a column-building hole having a predetermined depth can be formed. After the excavation of this column-building hole is completed, the auger device is pulled up and stored on the side of the boom, and the utility pole is gripped by the gripping device provided at the tip of the boom, and the boom is appropriately operated in a state of gripping the utility pole so that the utility pole can be directly driven into the excavated column-building hole. In such a gripping type pole-digging and column-building vehicle, a series of column-building operations can be efficiently performed as compared with the case where the utility pole is suspended and operated using a winch or a crane.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when moving the gripping device that holds the utility pole downwards to insert the pole into the mounting hole, it is difficult for the worker to visually determine whether the lower end of the utility pole is in contact with the bottom of the mounting hole. If the worker continues to move the gripping part downwards without recognizing that the lower end of the utility pole is in contact with the bottom of the mounting hole, there is a risk that the gripping device or the utility pole may be damaged by a large reaction force (load) from the ground.

[0005] The present invention has been made in view of these problems, and aims to provide a control device for a gripping-type hole-digging and pole-erecting vehicle that can detect when a columnar object gripped by the gripping part has reached the bottom of the hole for erecting a pole. [Means for solving the problem]

[0006] To solve the above problems, the control device for a gripping-type hole-digging pole-erecting vehicle according to the present invention is characterized by comprising: a boom mounted on the vehicle body so as to be able to move up and down and extend and retract; a gripping part capable of gripping a columnar object; a support mechanism provided between the tip of the boom and the gripping part to change the posture of the gripping part relative to the tip of the boom; an operating device for operating the boom, the gripping part and the support mechanism; a load detector for detecting the load acting on the gripping part when the gripping part is gripping a columnar object; an operation control unit for controlling the operation of the boom, the gripping part and the support mechanism in accordance with the operation of the operating device; and an operation restricting unit that restricts the downward movement of the gripping part by the boom and the support mechanism when the load detected by the load detector falls below a preset threshold when the operation control unit is operating the boom and the support mechanism to move the gripping part that is gripping a columnar object downward.

[0007] In the control device for the gripping-type hole-digging pole-erecting vehicle with the above configuration, the operating device includes a gripping vertical operation device that is operated to move the gripping part vertically, the operation control unit controls the movement of the gripping part vertically by linking the luffing and extending / retracting operation of the boom and the operation of the support mechanism in response to the operation of the gripping vertical operation device, and the operation restricting unit preferably restricts the vertical downward movement of the gripping part by the boom and the support mechanism when the operation control unit operates the boom and the support mechanism to move the gripping part, which is gripping a columnar object, vertically downward, and the load detected by the load detector falls below the threshold. [Effects of the Invention]

[0008] According to the control device for the gripping-type hole-digging pole-erecting vehicle of the present invention, when moving the gripping part downward to insert the columnar object gripped by the gripping part into a pole-erecting hole (a hole for erecting a columnar object), if the load acting on the gripping part falls below a threshold, it is determined that the lower end of the columnar object has come into contact with the bottom of the pole-erecting hole, and the downward movement of the gripping part (columnar object) is automatically stopped. This prevents the operator from continuing to move the gripping part downward without noticing that the lower end of the columnar object has come into contact with the bottom of the hole (resulting in the lower end of the columnar object being pressed excessively against the bottom of the hole), thereby preventing excessive load from being applied to the gripping part or the columnar object and causing damage. [Brief explanation of the drawing]

[0009] [Figure 1] This is a side view of the gripping type hole-digging and pole-erecting vehicle according to this embodiment. [Figure 2] The above is a plan view of the gripping-type hole-digging and pole-erecting vehicle. [Figure 3] This is a side view showing the usage of the gripping-type hole-digging and pole-erecting vehicle described above. [Figure 4] This is a perspective view of the auger device installed on the gripping-type hole-digging and pole-erecting vehicle described above. [Figure 5] This is a perspective view of the gripping device provided on the gripping-type hole-digging and pole-erecting vehicle described above. [Figure 6]It is a perspective view of the main part of the above gripping device seen from the right side. [Figure 7] It is a perspective view of the main part of the above gripping device seen from the left side. [Figure 8] It is a cross-sectional view of the above gripping device. [Figure 9] It is a longitudinal sectional view of the above gripping device. [Figure 10] It is a side view of the pillar extraction device provided on the above gripping type hole-digging and pillar-erecting vehicle. [Figure 11] It is a functional block diagram of the above gripping type hole-digging and pillar-erecting vehicle. [Figure 12] It is a schematic diagram for explaining the operation of making the gripping part of the above gripping device in a horizontal posture. [Figure 13] It is a conceptual diagram for explaining the relationship between the load acting on the above gripping part and the displacement amount when the above gripping part is moved vertically downward. [Figure 14] It is a schematic diagram showing the excavation work of the above gripping type hole-digging and pillar-erecting vehicle. [Figure 15] It is a schematic diagram showing the operation of the gripping part when the automatic vertical switch provided on the above gripping type hole-digging and pillar-erecting vehicle is operated. [Figure 16] It is a schematic diagram for explaining the direction of the load acting on the above gripping part in the process of inserting the utility pole gripped by the above gripping part into the pillar erection hole. [Figure 17] It is a schematic diagram showing the flow of the automatic pillar extraction work using the above pillar extraction device. [Figure 18] It is a schematic diagram showing the flow of the automatic pillar erection work using the above pillar extraction device (continuation of the above Fig. 17). <> [Figure 19] It is a schematic diagram showing the flow of the automatic pillar erection work using the above pillar extraction device (continuation of the above Fig. 18).

Embodiments for Carrying out the Invention

[0010] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. First, the overall configuration of the gripping type hole-digging and pillar-erecting vehicle 1 according to this embodiment will be described with reference to FIGS. 1 to 3.

[0011] The handheld hole-digging column-building vehicle 1 is configured based on a truck vehicle that has a cab 7 at the front of the vehicle body 2 and can travel by a pair of left and right tire wheels 5 arranged before and behind the vehicle body 2, as shown in FIG. 1. Jacks 9 for lifting and supporting the vehicle body 2 are arranged at four locations, namely, 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 therein to extend downward, thereby stabilizing the entire vehicle body ២. The operation of the jack 9 is performed by operating a jack operating device (not shown) provided at the rear of the vehicle body ២.

[0012] In the mounting area behind the cab 7 in the vehicle body 2, a turntable 12 is provided, which is driven by a swivel motor 14 (see FIG. 11) and is configured to be horizontally swiveling about a vertical axis. The base end portion of a boom 13 is attached to the turntable 12 so as to be swingable (up and down freely) in the vertical direction.

[0013] The boom 13 has a configuration in which a base boom 13a, an intermediate boom 13b, and a tip boom 13c are combined in a telescopic manner in order from the turntable 12 side. By the telescopic drive of a telescopic cylinder 15 (see FIG. 11) provided therein, the boom 13 can be telescopically moved in the axial direction (longitudinal direction). Further, a tilting cylinder 16 is straddled between the base boom 13a and the turntable 12. By telescopic driving of this tilting cylinder 16, the entire boom 13 can be tilted in the upper and lower surfaces (vertical plane).

[0014] The boom 13 is fitted with an auger support 17 that can be selectively connected to the base boom 13a and the tip boom 13c. As shown in Figure 4, the upper shaft portion 27a of a connecting rod member 27 is pivotally connected to the auger support 17 so as to be able to swing in the left-right direction. An auger device 20 for excavating a pole hole is pivotally connected to the lower shaft portion 27b of the connecting rod member 27 so as to be able to swing in the front-rear direction. The auger device 20 consists of an auger motor section 21 pivotally connected to the lower shaft portion 27b of the connecting rod member 27, and an auger screw (earth auger) 25 that rotates around its axis when the auger motor section 21 is operated. The auger motor section 21 has an auger motor 22 that rotates hydraulically, an auger reducer 23 connected to the output shaft of the auger motor 22, and an auger housing 24 that houses the auger motor 22 and the auger reducer 23. A drive shaft (not shown) of the auger reducer 23 protrudes from the lower end of the auger housing 24, and the upper end of the auger screw 25 is connected to this drive shaft.

[0015] Furthermore, an auger storage device 18 is provided on the side of the base boom 13a to hold the auger device 20 in a stored state. The auger device 20 is attached to the auger support 17 via a connecting rod member 27 so as to be able to swing up and down in a vertical plane, and the auger device 20 can swing between a stored position in which it 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 detached from the auger storage device 18 and the auger screw 25 is suspended toward the ground. When the auger device 20 is in the working position, the auger screw 25 is suspended from the tip of the boom 13 so as to be able to swing back and forth and left and right with the two shafts 27a and 27b of the connecting rod member 27 as pivot points, so that the auger screw 25 takes a vertical position along the direction of gravity (vertical direction) regardless of the orientation of the boom 13.

[0016] When using the auger device 20, as shown in Figure 3I, the auger support 17 is connected to the tip boom 13c, and the auger device 20, which has been detached from the auger storage device 18, is swung to the working position (with the auger screw 25 in a position approximately perpendicular to the ground). The auger screw 25 is rotated by the rotational drive of the auger motor 22, and the boom 13 is moved linearly downward in conjunction with its lowering and retracting operations, thereby enabling the excavation of the pole hole. On the other hand, when the auger device 20 is not used, as shown in Figure 3II, 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 operations such as erecting and removing utility poles (indicated by the symbol P in Figure 3; the same applies hereafter) and relocating obstacles can be performed using the gripping device 50 described later.

[0017] An arm bracket 19 is fixed to the tip of the tip boom 13c. A gripping device 50 for gripping objects (columnar objects) such as utility poles or trees is attached to this arm bracket 19. The configuration of this gripping device 50 will be explained with additional reference to Figures 5 to 9. Note that in Figures 8 to 9, the hatching indicating the cross-section has been omitted for clarity. Also, for the sake of explanation, the orientation of the gripping device 50 shown in Figure 5 will be used as the reference, and the directions of the arrows indicating front / back, left / right, and up / down will be referred to as the front / back direction, left / right direction, and up / down direction.

[0018] The gripping device 50 comprises an arm 51 mounted on an arm bracket 19 so as to be able to swing (flex and extend) in the vertical direction, a first joint member 60 mounted on the tip of the arm 51 so as to be able to swing (vertical pivot) in the vertical direction, a second joint member 70 mounted on the first joint member 60 so as to be able to swing (lateral pivot) in the left-right direction, and a gripper 80 mounted on the second joint member 70 so as to be able to rotate. In this embodiment, the arm 51, the first joint member 60, the second joint member 70, the vertical pivot cylinder 62, the horizontal pivot cylinder 71, the gripper motor 79, etc., constitute a support mechanism that changes the posture of the gripping portion 81 of the gripper 80.

[0019] The arm 51 is pivotally connected to the arm bracket 19 at one end in the axial direction (longitudinal direction) via a connecting pin 52, and its other end in the axial direction (longitudinal direction) is pivotally connected to the first joint member 60 via a connecting pin 53. An arm cylinder 55 is mounted between the arm bracket 19 and the first joint member 60. The rod end of the arm cylinder 55 is pivotally connected to the arm bracket 19 via a connecting pin 56. The bottom end of the arm cylinder 55 is pivotally connected to the first joint member 60 via a connecting pin 57. By extending and retracting this arm cylinder 55, the arm 51 is configured to swing freely (flex and extend freely) in the vertical direction around the connecting pin 52 relative to the arm bracket 19.

[0020] 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 this 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 end of the vertical swivel cylinder 62 is pivotally connected to the base end of the arm 51 via a connecting pin 63. The rod end of the vertical swivel cylinder 62 is pivotally connected to the upper end of the first joint member 60 via a connecting pin 64. By extending and retracting this vertical swivel cylinder 62, the first joint member 60 is configured to swing freely in the vertical direction (vertical swivel) relative to the arm 51 around the connecting pin 53.

[0021] The second joint member 70 is supported by the first joint member 60, sandwiched between it from above and below. A lateral swivel cylinder 71 is provided at the upper end of the first joint member 60. The bottom end of the lateral swivel cylinder 71 is pivotally connected to the tip of the first joint member 60, and the rod end is pivotally connected to the rear end of the second joint member 70. By extending and retracting this lateral swivel cylinder 71, the second joint member 70 is configured to swing freely (swivel freely) in the left-right direction around the connecting pin 61 relative to the first joint member 60.

[0022] The gripper 80 has a gripping part 81 for gripping an object and a second joint that supports the gripping part 81. The system comprises a gripper housing 86 rotatably mounted on the gripper member 70, and an opening / closing mechanism 93 that opens and closes the gripping portion 81.

[0023] The gripping section 81 comprises a pair of gripping claws 82 and a pair of upper and lower support plates 83 that support the pair of gripping claws 82 so that they can be opened and closed in directions that bring them closer together or further apart (opening and closing directions). The gripping claws 82 are configured to grip various objects (columnar objects) such as utility poles and trees. The base ends of the gripping claws 82 are pivotally connected to the upper and lower support plates 83 via connecting pins 84. The tips of the gripping claws 82 have alternating notches 82a and 82b, and these tips are configured to intersect (overlap) with each other. The support plates 83 are provided with a flat upper bracket 85 for detachably attaching an attachment (not shown) (for example, a tree felling device for felling trees).

[0024] The gripper housing 86 includes a support cylinder portion 87 connected to the upper and lower support plate portions 83 and rotatably supported by the second joint member 70, and a cylinder bracket portion 92 fixed to the base end side of the support cylinder portion 87 and disposed between the first joint member 60 and the second joint member 70.

[0025] The support cylinder portion 87 has a double structure, comprising an inner cylinder portion 88 formed in the shape of a hollow rectangular tube, and an outer cylinder portion 89 formed in the shape of a hollow cylindrical tube and provided on the outer circumference of the inner cylinder portion 88. A sliding member 95 of the opening / closing mechanism 93, described later, is mounted on the inner circumference of the inner cylinder portion 88 so as to be slidable in the front-rear direction. A worm wheel 90 is mounted on the outer circumference of the outer cylinder portion 89 concentrically with the outer cylinder portion 89. This worm wheel 90 meshes with a worm pinion 91 that is rotatably supported inside the second joint member 70. A gripper motor 79 is mounted on the upper end of the second joint member 70, and the worm pinion 91 is connected to the output shaft of this gripper motor 79 via a reduction gear. When this gripper motor 79 is rotated in the forward direction, the entire gripper 80 rotates in a predetermined direction around the rotation axis X (see Figure 8) via the worm pinion 91 and worm wheel 90. On the other hand, when the gripper motor 79 is rotated in the reverse direction, the entire gripper 80 rotates in the opposite direction to the predetermined direction around the rotation axis X (see Figure 8) via the worm pinion 91 and worm wheel 90. In the orientation of the gripping device 50 shown in Figure 5, the rotation axis X direction of the gripper 80 (gripping part 81) corresponds to the front-to-back direction, and the opening and closing direction (gripping direction) of the gripping part 81 corresponds to the left-to-right direction.

[0026] The opening / closing mechanism 93 comprises a pair of link members 94, a sliding member 95 linked 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 other ends of the pair of link members 94 are also pivotally connected to the tip of the sliding member 95 via a connecting pin 97, with the other ends of each link member 94 overlapping vertically. The sliding member 95 is inserted into the hollow part of the inner cylindrical portion 88 and is mounted so as to be slidable (reciprocal) along the inner circumferential surface of the inner cylindrical portion 88. A slider 98 made of synthetic resin is attached between the outer circumferential surface of the sliding member 95 and the inner circumferential surface of the inner cylindrical portion 88 to guide the sliding (reciprocating) movement of the sliding member 95. The rod-side end of the gripper cylinder 99 is connected to the base end of the sliding member 95. The bottom end of the gripper cylinder 99 is connected to the 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, causing the link members 94 to swing away from each other. As a result, the gripping claws 82 swing in the opening direction with the connecting pin 84 as the pivot point (the gripping claws 82 operate in the opening direction (opening operation)), releasing the grip on the object. On the other hand, when the gripper cylinder 99 is retracted, the sliding member 95 slides in the retraction direction, causing the link members 94 to swing towards each other. As a result, the gripping claws 82 swing in the closing direction with the connecting pin 84 as the pivot point (the gripping claws 8 The object can be gripped by the closing action of part 2 (closing action). Since the opening and closing mechanism 93 is configured symmetrically, the pair of gripping claws 82 open and close symmetrically.

[0027] On the side of the turntable 12 in the vehicle body 2, there is an operator's seat 30 for operating each work device (turntable 12, boom 13, auger device 20, gripping device 50). In front of this operator's seat 30, there is an operating device 31 that can be operated by the operator while seated. As shown in Figure 11, the operating device 31 is equipped with a boom rotation and luffing lever 32a for rotating and luffing the boom 13, a boom extension and bending lever 32b for extending and retracting the boom 13 and bending the arm 51, an auger operating lever 32c for rotating the auger screw 25, a gripper vertical swing lever 32d for vertical swinging the gripper 81, a gripper horizontal swing lever 32e for horizontal swinging the gripper 81, a gripper rotation lever 32f for rotating the gripper 81, and a gripper opening and closing lever 32g for opening and closing the gripper 81.

[0028] Furthermore, the operating device 31 is provided with a pole-pulling machine operating lever 32h for operating the pole-pulling machine 40, which is used as an optional hydraulic device (for pulling out utility poles). As shown in Figure 10, the pole-pulling machine 40 is composed of a pole-pulling machine cylinder 41 that extends and retracts hydraulically, a base plate 44 provided at the lower end of the pole-pulling machine cylinder 41 and grounded, and a chain 45 that is locked to the upper end of the pole-pulling machine cylinder 41 and wrapped around a utility pole (indicated by the symbol P in Figure 10). The pole-pulling machine cylinder 41 is composed of a cylinder tube 42 and a piston rod 43 that is assembled to the cylinder tube 42 so as to be extendable and retractable in the vertical direction. Both ends of the chain 45 are detachably locked to the upper end of the cylinder tube 42 of the pole-pulling machine cylinder 41. The chain 45 is formed to a length that allows it to be wrapped around the outer circumference of a utility pole several times. A base plate 44 is pivotally attached to the lower end of the piston rod 43, allowing it to swing freely around a support shaft 44a (so that it can swing according to the slope and unevenness of the ground). In addition, a hydraulic hose 46 connected to the bottom oil chamber of the cylinder tube 42 and a hydraulic hose 47 connected to the rod-side oil chamber of the cylinder tube 42 are connected to the pole-pulling machine cylinder 41. By connecting these hydraulic hoses 46 and 47 to a hydraulic outlet for the pole-pulling machine (not shown) provided on the vehicle body 2 using a sealed coupling (one-touch joint), each oil chamber of the pole-pulling machine cylinder 41 (bottom oil chamber, rod oil chamber) and each port of the electromagnetic proportional control valve V10 are connected via this hydraulic outlet for the pole-pulling machine, enabling the supply and discharge of hydraulic fluid (pressurized oil) between the pole-pulling machine cylinder 41 and the electromagnetic proportional control valve V10.

[0029] Furthermore, as shown in Figure 11, the operating device 31 is equipped with a mode selection switch 33, an automatic vertical switch 34, and an automatic column removal switch 35.

[0030] The mode selection switch 33 is a toggle switch that can be switched to one of the following positions: neutral, forward, or backward (it is configured to maintain the selected operating position even if the operator releases their hand). When the mode selection switch 33 is selected to the neutral position, the normal mode is set; when the mode selection switch 33 is selected to the forward position, the auger vertical operation mode is set; and when the mode selection switch 33 is selected to the backward position, the gripping unit vertical operation mode is set. The normal mode is a mode in which each hydraulic actuator is operated independently in response to the operation of each operating lever 32a to 32h, allowing for individual luffing, extension, and slewing of the boom 13, rotation of the auger device 20 (auger screw 25), bending and extending of the arm 51, vertical swivel, horizontal swivel, rotation, and opening / closing of the gripping unit 81, and extension and retraction of the column removal machine 40. The auger vertical operation mode is a mode in which the luffing cylinder 16 and the telescopic cylinder 15 are operated in combination (interlocked operation) in response to the operation of the boom slewing and luffing operation lever 32a, thereby moving the auger device 20 (the tip of the boom 13) vertically (up and down). The gripping part vertical operation mode is This mode allows the gripping section 81 to be moved vertically (up and down) by operating the luffing cylinder 16, the telescopic cylinder 15, and the vertical swivel cylinder 62 in combination (interlocking operation) in response to the operation of the boom slewing and luffing lever 32a.

[0031] The automatic vertical switch 34 is configured as a toggle switch that can be switched to either the ON position or the OFF position (it is configured to maintain the switched operating position even if the operator releases their hand). When the automatic vertical switch 34 is selected to the ON position, as will be described in detail later, the vertical swivel cylinder 62 and the gripper motor 79 are activated to cause the gripping part 81 to swivel vertically and rotate, thereby making the gripping part 81 a horizontal position (that is, the utility pole gripped by the gripping part 81 can be made vertical). Note that the operation of the automatic vertical switch 34 is effective (the operation signal is effectively received) when the angle of inclination of the gripping part 81 with respect to the horizontal plane, as detected by the gripping part inclination angle detector 124 (see Figure 11), described later, is within a predetermined angle.

[0032] The automatic pole removal switch 35 is configured as a toggle switch that can be switched to either the ON position or the OFF position (it is configured to maintain the switched operating position even if the operator releases their hand). When the automatic pole removal switch 35 is selected to the ON position, as will be described in detail later, the gripper cylinder 99 and the pole removal machine cylinder 41 are operated in conjunction, and by combining the opening and closing operation of the gripping part 81 and the extension and retraction operation of the pole removal machine 40, the pole removal work of pulling an existing utility pole out of the ground can be performed automatically.

[0033] Here, the operating mechanisms of the turntable 12, boom 13, auger device 20, gripping device 50, and pole removal machine 40 are configured as shown in Figure 11, with a controller 100 that receives operation signals from the operating device 31 and controls the turntable motor 14, telescopic cylinder 15, luffing cylinder 16, auger motor 22, arm cylinder 55, vertical swivel cylinder 62, horizontal swivel cylinder 71, gripper motor 79, gripper cylinder 99, and pole removal machine cylinder 41 (hereinafter collectively referred to as "hydraulic actuators"), and a hydraulic unit 110 that supplies hydraulic fluid to drive these hydraulic actuators.

[0034] The operation signal output by the operation of the operating device 31 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).

[0035] The hydraulic unit 110 comprises a hydraulic pump 111 that discharges hydraulic fluid and control valves 112 that control the direction and amount of hydraulic fluid supplied from the hydraulic pump 111 to each hydraulic actuator. The hydraulic pump 111 is driven by power taken from the vehicle's engine via a PTO mechanism (not shown). The control valves 112 include 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 luffing cylinder 16, an electromagnetic proportional control valve V4 corresponding to the auger motor 22, 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, an electromagnetic proportional control valve V9 corresponding to the gripper cylinder 99, and an electromagnetic proportional control valve V10 corresponding to the pole removal cylinder 41. Based on command signals from the controller 100, the control valve 112 electromagnetically drives the spools of each electromagnetic proportional control valve V1 to V10 to control the supply direction and amount of hydraulic fluid supplied from the hydraulic pump 111 to each hydraulic actuator, thereby controlling the operating direction and operating speed of each hydraulic actuator (controlling the operating direction and operating speed of the turntable 12, boom 13, auger device 20, gripping device 50, and column removal machine 40).

[0036] The controller 100 includes a boom luffing angle detector 120, a boom extension amount detector 121, Various detectors, such as the boom rotation angle detector 122, auger tilt angle detector 123, gripping section tilt angle detector 124, gripping section load detector 125, gripper cylinder pressure detector 126, and column removal machine cylinder pressure detectors 127 and 128, are electrically connected.

[0037] The boom luffing angle detector 120 is installed inside the base boom 13a and detects the luffing angle of the boom 13. The boom extension amount detector 121 is installed at the base end of the base boom 13a and detects the length (extension amount) of the boom 13. The boom slewing angle detector 122 is installed on the vehicle body 2 and detects the slewing angle of the boom 13 (slewing body 12).

[0038] The auger tilt angle detector 123 is mounted on the upper part of the auger motor unit 21 (auger housing 24). This auger tilt angle detector 123 detects the tilt angle of the auger device 20 (auger screw 25). As mentioned above, the auger device 20 is suspended from the tip of the boom 13 so as to be able to swing back and forth and left and right with the two shaft portions 27a and 27b of the connecting rod member 27 as fulcrums, so that the auger screw 25 takes a vertical position along the direction of gravity (vertical direction) regardless of the position of the boom 13. Therefore, when the auger device 20 is excavating a hole for erecting a pole (indicated by the symbol "K" in Figure 14), if the excavation resistance of the ground is large, the axis of the auger screw 25 may tilt back and forth and left and right with respect to the vertical line (vertical direction). The auger tilt angle detector 123 is composed of a two-axis tilt angle detector that detects the tilt angle of the auger screw 25 in the left-right direction (X-axis direction) and the tilt angle in the front-back direction (Y-axis direction) relative to the vertical direction of the auger screw 25. This auger tilt angle detector 123 detects the tilt angle of the auger screw 25 in the left-right direction and the tilt angle in the front-back direction and outputs a voltage signal (detection signal) corresponding to the detected tilt angle to the controller 100.

[0039] The gripping section tilt angle detector 124 is mounted on the upper surface of the gripping section 81 (support plate section 83). This gripping section tilt angle detector 124 is a two-axis tilt angle detector that detects the tilt angle of the gripping section 81 with respect to the horizontal plane, specifically the tilt angle in the left-right direction (X-axis direction) and the tilt angle in the front-back direction (Y-axis direction). This gripping section tilt angle detector 124 detects the tilt angle of the gripping section 81 in the left-right direction and the tilt angle in the front-back direction, and outputs a voltage signal (detection signal) corresponding to the detected tilt angle to the controller 100.

[0040] The gripping section load detector 125 is a so-called pin-type load cell and is configured as the connecting pin 63 that pivotally connects the bottom end of the vertical swivel cylinder 62 and the base end of the arm 51. This gripping section load detector 125 detects the axial load (the axial direction of the vertical swivel cylinder 62) acting from the vertical swivel cylinder 62 to the connecting pin 63 and outputs a voltage signal (detection signal) corresponding to the detected load to the controller 100. The load detected by this gripping section load detector 125 (the load acting on the connecting pin 62) is proportional to the load acting on the gripping section 81 (the load that the gripping section 81 receives in the vertical plane). Therefore, as will be described in detail later, the controller 100 determines the load acting on the gripping section 81 based on the load detected by this gripping section load detector 125.

[0041] The gripper cylinder pressure detector 126 is installed in the oil passage connecting the electromagnetic proportional control valve V9 and the bottom oil chamber of the gripper cylinder 99, and detects the pressure of the hydraulic fluid supplied to the bottom oil chamber of the gripper cylinder 99 (pressure in the bottom oil chamber). This gripper cylinder pressure detector 126 detects the pressure in the bottom oil chamber of the gripper cylinder 99 and outputs a voltage signal (detection signal) corresponding to the detected pressure to the controller 100. The pressure detected by this gripper cylinder pressure detector 126 is proportional to the gripping force of the gripping part 81 (the force with which the gripping part 81 grips an object). Therefore, as will be described in detail later, the controller 100 determines the gripping force of the gripping part 81 based on the pressure detected by this gripper cylinder pressure detector 126.

[0042] The column removal machine cylinder pressure detector 127 is installed in the oil passage connecting the electromagnetic proportional control valve V10 and the bottom oil chamber of the column removal machine cylinder 41, and detects the pressure of the hydraulic fluid supplied to the bottom oil chamber of the column removal machine cylinder 41 (pressure in the bottom oil chamber). The column removal machine cylinder pressure detector 128 is installed in the oil passage connecting the electromagnetic proportional control valve V10 and the rod-side oil chamber of the column removal machine cylinder 41, and detects the pressure of the hydraulic fluid supplied to the rod-side oil chamber of the column removal machine cylinder 41 (pressure in the rod-side oil chamber). These column removal machine cylinder pressure detectors 127 and 128 detect the pressure of the hydraulic fluid supplied to each oil chamber (bottom oil chamber, rod-side oil chamber) of the column removal machine cylinder 41 and output a voltage signal (detection signal) corresponding to the detected pressure to the controller 100. In this embodiment, the stroke end in the extension and retraction direction of the column removal machine cylinder 41 is detected based on the pressure detected by the column removal machine cylinder pressure detectors 127 and 128.

[0043] The controller 100 includes a position calculation unit 101, an operation control unit 102, an auger inclination determination unit 103, a gripping determination unit 104, an automatic vertical control unit 105, a load determination unit 106, and an automatic column removal control unit 107.

[0044] The position calculation unit 101 calculates the position of the tip of the boom 13 relative to the vehicle body 2 based on the detection information from the boom luffing angle detector 120, the boom extension amount detector 121, and the boom slewing angle detector 122.

[0045] The operation control unit 102 controls the operation of each actuator according to the operation signal (operation command) output from the operating device 31, based on the operation mode selected by the mode selection switch 33. The operation modes will be described below.

[0046] (Normal mode) When the mode selection switch 33 is selected for normal mode, the operation control unit 102 independently operates each hydraulic actuator in accordance with the operation of each operation lever 32a to 32h. Specifically, when the boom slewing / luffing operation lever 32a is tilted forward (in the forward, backward, left, and right directions relative to the operator operating it; the same applies hereinafter), the luffing cylinder 16 is retracted to lower the boom 13, and when the boom slewing / luffing operation lever 32a is tilted backward, the luffing cylinder 16 is extended to raise and lower the boom 13. Also, when the boom extension / bending operation lever 32b is tilted forward, the extension cylinder 15 is extended to extend the boom 13, and when the boom extension / bending operation lever 32b is tilted backward, the extension cylinder 15 is retracted to retract the boom 13. Furthermore, when the boom slewing / luffing lever 32a is tilted to the left, the slewing motor 14 is operated in the forward direction to slewing the boom 13 counterclockwise, and when the boom slewing / luffing lever 32a is tilted to the right, the slewing motor 14 is operated in the reverse direction to slewing the boom 13 clockwise. Also, when the auger operation lever 32c is tilted forward, the auger motor 22 is operated in the reverse direction to rotate the auger screw 25 in the reverse direction, and when the auger operation lever 32c is tilted backward, the auger motor 22 is operated in the forward direction to rotate the auger screw 25 in the forward direction. Furthermore, when the boom extension / bending operation lever 32b is tilted to the left, the arm 51 is operated to bend downward relative to the tip of the boom 13, and when the boom extension / bending operation lever 32b is tilted to the right, the arm 51 is operated to bend upward relative to the tip of the boom 13. Furthermore, when the gripping unit's vertical swivel operation lever 32d is tilted forward, the vertical swivel cylinder 62 is extended to swing the gripping unit 81 downward (vertical swivel), and when the gripping unit's vertical swivel operation lever 32d is tilted backward, the vertical swivel cylinder 62 is retracted to swing the gripping unit 81 upward (vertical swivel). Also, when the gripping unit's horizontal swivel operation lever 32e is tilted to the left, the horizontal swivel cylinder 71 is extended. When the gripping part 81 is extended, it swings to the left (lateral oscillating motion). When the gripping part vertical oscillating lever 32e is tilted to the right, the lateral oscillating cylinder 71 is retracted, causing the gripping part 81 to swing to the right (lateral oscillating motion). Also, when the gripping part rotation lever 32f is tilted forward, the gripper motor 79 is operated in the forward direction, causing the gripping part 81 to rotate clockwise. When the gripping part rotation lever 32f is tilted backward, the gripper motor 79 is operated in the reverse direction, causing the gripping part 81 to rotate counterclockwise. Furthermore, when the gripping section opening / closing lever 32g is tilted forward, the gripper cylinder 99 is retracted to operate the gripping section 81 in the closing direction (direction for gripping the object), and when the gripping section opening / closing lever 32g is tilted backward, the gripper cylinder 99 is extended to operate the gripping section 81 in the opening direction (direction for releasing the object). Also, when the pole removal machine operating lever 32h is tilted forward, the pole removal machine cylinder 41 is extended to operate the pole removal machine 40, and when the pole removal machine operating lever 32h is tilted backward, the pole removal machine cylinder 41 is retracted to operate the pole removal machine 40.

[0047] (Auger vertical operation mode) Furthermore, when the boom slewing and luffing operation lever 32a is operated while the mode selection switch 33 is selected for auger vertical operation mode, the operation control unit 102, based on the position information (current position) of the tip of the boom 13 calculated by the position calculation unit 101, combines and operates the extension and retraction of the luffing cylinder 16 and the extension and retraction of the telescopic cylinder 15 in a linked manner, and moves the auger screw 25 (tip of the boom 13) vertically in accordance with the operation of the boom slewing and luffing operation lever 32a. Specifically, when the boom slewing and luffing operation lever 32a is tilted forward, the extension and retraction of the luffing cylinder 16 and the extension and retraction of the telescopic cylinder 15 are combined to move the auger screw 25 vertically downward, and when the boom slewing and luffing operation lever 32a is tilted backward, the extension and retraction of the luffing cylinder 16 and the extension and retraction of the telescopic cylinder 15 are combined to move the auger screw 25 vertically upward.

[0048] (Grip section vertical operation mode) Furthermore, when the boom slewing and luffing operation lever 32a is operated while the mode selection switch 33 is selected for the gripping unit vertical operation mode, the operation control unit 102 combines and operates the extension and retraction of the luffing cylinder 16, the extension and retraction of the telescopic cylinder 15, and the extension and retraction of the vertical swivel cylinder 62 in conjunction with the position information (current position) of the tip of the boom 13 calculated by the position calculation unit 101 and the inclination angle of the gripping unit 81 detected by the gripping unit inclination angle detector 124, thereby moving the gripping unit 81 (the object gripped by the gripping unit 81) vertically in response to the operation of the boom slewing and luffing operation lever 32a. Specifically, when the boom slewing and luffing lever 32a is tilted forward, the gripping section 81 is moved vertically downward by combining the retraction of the luffing cylinder 16, the retraction of the telescopic cylinder 15, and the retraction of the vertical swivel cylinder 62. When the boom slewing and luffing lever 32a is tilted backward, the gripping section 81 is moved vertically upward by combining the extension of the luffing cylinder 16, the extension of the telescopic cylinder 15, and the extension of the vertical swivel cylinder 62. Specifically, the vertical operation control of the gripping section 81 is performed by combining two controls: one that moves the tip of the boom 13 vertically by combining the extension and retraction of the luffing cylinder 16 and the extension and retraction of the telescopic cylinder 15, based on the position information of the tip of the boom 13 calculated by the position calculation unit 101; and another that maintains the gripping section 81 (the rotation axis X of the gripping section 81) in a horizontal state by extending and retracting the vertical swivel cylinder 62, based on the detection information (the angle of inclination of the gripping section 81 with respect to the horizontal plane) detected by the gripping section inclination angle detector 124.

[0049] The auger tilt determination unit 103 determines the orientation of the auger device 20 (auger screw 25) based on the detection information from the auger tilt angle detector 123. Specifically, the auger tilt determination unit 103 compares the tilt angle of the auger screw 25 detected by the auger tilt angle detector 123 with a preset allowable angle (threshold angle) and determines the orientation of the auger screw 25. The system determines whether the inclination angle exceeds the allowable angle. The inclination angle of the auger screw 25 is the angle at which the axis of the auger screw 25 is tilted in the forward, backward, left, or right directions relative to the vertical direction. For example, the allowable angle is set to 5 degrees (however, this can be changed at will). In this case, when the auger inclination determination unit 103 is performing an excavation operation that combines the rotational operation and vertical descent operation of the auger screw 25 in the auger vertical operation mode, if it determines that the inclination angle of the auger screw 25 is within the allowable angle, it allows the excavation operation. If it determines that the inclination angle of the auger screw 25 exceeds the allowable angle, it outputs a restriction signal to the operation control unit 102 to restrict the excavation operation. When the operation control unit 102 receives a restriction signal from the auger inclination determination unit 103, it blocks the control signals from the operation control unit 102 to the control valve 112 that cause the auger screw 25 to rotate and to descend vertically, thereby forcibly stopping the excavation operation of the auger screw 25. This prevents the auger screw 25 from operating at an angle exceeding the allowable angle during excavation (resulting in the pole hole being formed at an angle). In this case, the excavation operation of the auger screw 25 (rotation and vertical descent) is restricted, but the operation of moving the auger screw 25 vertically upward from the pole hole being excavated (vertical ascent) is permitted. Therefore, if the excavation operation of the auger screw 25 is restricted, the auger screw 25 can be moved vertically upward and withdrawn from the excavation hole, returning it to a vertical position (facing vertically downward) by its own weight. After returning the auger screw 25 to a vertical position in this way, the pole hole being excavated (the same pole hole) can be restarted from where it left off by rotating and vertically descending the auger screw 25 again.

[0050] The gripping determination unit 104 determines the gripping state of the gripping unit 81 based on the detection information from the gripper cylinder pressure detector 126. Specifically, the gripping determination unit 104 determines that the gripping unit 81 is gripping the utility pole (object) (that the gripping unit 81 is gripping the utility pole with a specified gripping force) when the pressure detected by the gripper cylinder pressure detector 126 rises to or above a preset first threshold pressure. Furthermore, the gripping determination unit 104 determines that the gripping unit 81's grip on the utility pole (object) has been loosened (that the gripping force has been weakened to the extent that the utility pole will not fall off the gripping unit 81) when the pressure detected by the gripper cylinder pressure detector 126 falls to or below a preset second threshold pressure (provided that the first threshold pressure > the second threshold pressure).

[0051] When the automatic vertical switch 34 of the operating device 31 is turned ON, the automatic vertical control unit 105 determines whether the tilt angle of the gripping section 81 detected by the gripping section tilt angle detector 124 is within a predetermined angle (for example, within 5 degrees). The automatic vertical control unit 105 stores an automatic vertical program, and when it determines that the tilt angle of the gripping section 81 is within a predetermined angle when an operation signal is input from the automatic vertical switch 34, it outputs a command signal to the operation control unit 102 based on the detection information from the gripping section tilt angle detector 124, according to this automatic vertical program. When the operation control unit 102 receives a command signal from the automatic vertical control unit 105, it feeds back the tilt angle of the gripping unit 81 from the gripping unit tilt angle detector 124. Based on this feedback information, it extends and retracts the vertical swivel cylinder 62 until the tilt angle of the gripping unit 81 in the front-rear direction reaches the target angle (0 degrees) to correct the tilt of the gripping unit 81 in the front-rear direction, and rotates the gripper motor 79 until the tilt angle of the gripping unit 81 in the left-right direction reaches the target angle (0 degrees) to correct the tilt of the gripping unit 81 in the left-right direction. The tilt of the gripping unit 81 in the front-rear direction can be corrected by extending the vertical swivel cylinder 62 to tilt the gripping unit 81 downwards (see Y1 direction in Figure 12), and by retracting the vertical swivel cylinder 62 to tilt the gripping unit 81 upwards (see Y2 direction in Figure 12). Furthermore, regarding the left-right tilt of the gripping portion 81, by operating the gripper motor 79 in the forward direction, the gripping portion 81 is tilted to the left around the rotation axis X (see direction Z1 in Figure 12), and by operating the gripper motor 79 in the reverse direction, the gripping portion 81 is tilted to the right around the rotation axis X (see direction Z2 in Figure 12). (See reference) It can be tilted in this way. In this manner, the operation control unit 102 performs feedback control based on the deviation between the tilt angle of the gripping unit 81 and the target angle (0 degrees) based on the command from the automatic vertical control unit 105, and sets the gripping unit 81 to a horizontal position (the utility pole that the gripping unit 81 is gripping is in a vertical position). Note that this automatic vertical control is used not only when the gripping unit 81 is gripping a utility pole and the gripping unit 81 is set to a horizontal position (i.e., when the utility pole that the gripping unit 81 is gripping is set to a vertical position), but also when the gripping unit 81 is not gripping a utility pole (the gripping unit 81 is not gripping anything) and the gripping unit 81 is set to a horizontal position. As a variation, the automatic vertical control unit 105 may be configured to perform automatic vertical control only when the gripping determination unit 104 has determined that the gripping unit 81 is gripping a utility pole (object).

[0052] The load determination unit 106 determines the change in the load acting on the gripping part 81 based on the detection information from the gripping part load detector 125. Here, Figure 13 is a conceptual diagram showing the relationship between the load acting on the gripping part 81 and the displacement when the gripping part 81 is moved vertically downward. As shown in Figure 13, when the gripping part 81 is gripping the utility pole, a load corresponding to the weight of the utility pole acts downward on the gripping part (A in the figure). At this time, when the gripping part 81 is moved vertically downward and the lower end of the utility pole gripped by the gripping part 81 reaches the bottom of the hole for pole installation (B in the figure), the load acting on the gripping part 81 decreases due to the reaction force received from the bottom of the hole (a reaction force that tries to push the utility pole upward). Then, after the load on the gripping part 81 has decreased to 0 (C in the figure), the direction of the load reverses from downward to upward (D in the figure). Thus, the timing at which the utility pole contacts the bottom of the hole corresponds to the timing at which the direction of the load acting on the gripping part 81 reverses (the timing at which the load becomes 0). Therefore, when the gripping part 81 is gripping the utility pole, the load on the gripping part 81 detected by the gripping part load detector 125 during the vertical downward movement of the gripping part 81 decreases to a threshold load (0 in this embodiment), and the load determination unit 106 determines that the utility pole gripped by the gripping part 81 has contacted the bottom of the hole for pole installation. When the load determination unit 106 determines that the load detected by the gripping part load detector 125 has decreased to a threshold load (the object has contacted the bottom of the hole for pole installation), it outputs a restriction signal to the operation control unit 102 to restrict the vertical downward movement (downward movement in the vertical direction) of the gripping part 81. When the operation control unit 102 receives a restriction signal from the load determination unit 106, it ignores the operation signal for vertical downward movement of the gripping unit 81 among the operation signals input by the operation of the operating device 31, or blocks the control signal for vertical downward movement of the gripping unit 81 among the control signals from the operation control unit 102 to the control valve 112, thereby forcibly stopping the vertical downward movement of the gripping unit 81 that was being performed up to that point. As a result, even if the operation to move the gripping unit 81 vertically downward (the operation to move the utility pole downward) is performed further, the vertical downward movement of the gripping unit 81 is restricted.In this way, the downward movement of the gripping part 81 is restricted when the lower end of the utility pole comes into contact with the bottom (back end) of the hole for pole installation, thus preventing the lower end of the utility pole from being pressed too hard against the bottom of the hole.

[0053] When the automatic pole removal switch 35 of the operating device 31 is turned ON, the automatic pole removal control unit 107 operates the gripping unit 81 and the pole removal machine 40 in conjunction to perform an automatic pole removal operation to pull the existing utility pole out of the ground. This automatic pole removal operation includes the steps of releasing (releasing) the gripping unit 81 from its grip on the utility pole and extending the pole removal machine 40, and gripping the utility pole with the gripping unit 81 and retracting the pole removal machine 40. The automatic pole removal control unit 107 stores an automatic pole removal program, and when it receives an operation signal from the automatic pole removal switch 35, it outputs a command signal to the operation control unit 102 based on detection information from the gripper cylinder pressure detector 126 and the pole removal machine cylinder pressure detectors 127, 128, etc., in accordance with this automatic pole removal program, and controls the opening and closing operation of the gripping unit 81 and the extension and retraction operation of the pole removal machine 40 in conjunction to continuously execute each step of the automatic pole removal operation. Details of the column removal process (automatic column removal process) in this embodiment will be described later.

[0054] Next, the operation of the gripping-type hole-digging and pole-erecting vehicle 1 of this embodiment will be described below. The excavation, pole erection, and pole removal operations using the gripping-type hole-digging and pole-erecting vehicle 1 will be explained in order.

[0055] [1. Excavation work] First, let's explain the excavation work (hole digging operation) of the gripping-type hole-digging and pole-erecting vehicle 1. Figure 14 is a schematic diagram showing the excavation work by the auger device 20. Unless otherwise specified in the following explanation, the mode selection switch 33 is assumed to be in normal mode.

[0056] When performing excavation work with the gripping-type hole-digging pole-erecting vehicle 1, first, the auger support 17 is connected to the tip boom 13c, and then the operating device 31 is operated to raise and lower the boom 13 by a predetermined angle (for example, 60 degrees). In this state, the auger device 20 is detached from the auger storage device and suspended vertically downward from the tip of the boom 13. Next, the operating device 31 is operated to raise, extend, and rotate the boom 13 to move the auger screw 25 above the excavation position. Subsequently, the mode selection switch 33 is switched from normal mode to auger vertical operation mode, and while rotating the auger screw 22, the lowering and retracting operations of the boom 13 are linked to move the auger screw 25 vertically downward, thereby digging the ground vertically with the auger screw 25. At this time, as shown in Figure 14, if the ground being excavated is hard, the auger screw 25 (axis J) may tilt forward, backward, left, or right relative to the vertical due to the excavation reaction force (excavation resistance) from the ground. The tilt angle of the auger screw 25 is detected moment by moment by the auger tilt angle detector 123 provided on the upper surface of the auger device 20. Based on the detection information from the auger tilt angle detector 123, the auger tilt determination unit 103 of the controller 100 determines whether the tilt angle of the auger screw 25 exceeds the allowable angle. If the auger tilt determination unit 103 determines that the tilt angle of the auger screw 25 exceeds the allowable angle, it forcibly stops the rotation and vertical descent of the auger screw 25 (restricts the excavation operation of the auger screw 25). When the excavation operation of the auger screw 25 is restricted in this way, the worker operates the operating device 31 to vertically raise the auger screw 25, thereby pulling the auger screw 25 out of the ground (pole erection hole). This allows the auger screw 25 to return to a state where it is suspended vertically downward from the tip of the boom 13 by the action of its own weight. Then, by rotating and vertically lowering the auger screw 25 again and reinserting it into the pole-erecting hole being excavated, a vertical pole-erecting hole can be formed.

[0057] [2. Pole erection work] Next, the pole-erecting operation of the gripping-type hole-digging pole-erecting vehicle will be described. Figure 15 is a schematic diagram showing the operation of the gripping part 81 when the automatic vertical switch 34 is operated, and Figure 16 is a schematic diagram for explaining the direction of the load acting on the gripping part 81. Unless otherwise specified in the following description, the mode selection switch 33 is assumed to be in normal mode.

[0058] When performing pole erection work with the gripping-type hole-digging pole-erecting vehicle 1, first, the operating device 31 is operated to appropriately move the boom 13, as well as the bending and extending of the arm 51, and the vertical, horizontal, and rotational movements of the gripping unit 81, thereby moving the gripping unit 81 close to the utility pole (for example, a utility pole placed horizontally at the work site) and aligning the gripping unit 81 with the utility pole. Next, the pair of gripping claws 82 are operated in the closing direction (closed operation) to allow the gripping unit 80 to grip the utility pole. While the gripping unit 81 is gripping the utility pole in this state, the load acting on the gripping unit 81 is detected moment by moment by the gripping unit load detector 125, and this detection signal is input to the controller 100. Then, the boom 13 and gripping device 50 are operated appropriately to lift the utility pole gripped by the gripping unit 81 and move it above the pole erection hole (the pole erection hole excavated in the aforementioned excavation work). Above this pole installation hole, the operator operates the control device 31 to visually bring the utility pole closer to a vertical position, as shown in Figure 15(A). At this point, the operator turns on the automatic vertical switch 34. When the automatic vertical control unit 105 of the controller 100 receives an operation signal from the automatic vertical switch 123 and determines that the tilt angle of the gripping part 81 is within a predetermined angle, it outputs a command signal to the operation control unit 102. When the operation control unit 102 receives the command signal from the automatic vertical control unit 105, it operates the vertical swivel cylinder 62 to extend and retract based on the detection information from the gripping part tilt angle detector 124 to correct the tilt of the gripping part 81 in the front-to-back direction, and also operates the gripper motor 79 to rotate to correct the tilt of the gripping part 81 in the left-to-right direction, thereby setting the gripping part 81 to a horizontal position. As a result, as shown in Figure 15(B), the utility pole gripped by the gripping part 81 can be set to a vertical position. Furthermore, if the position (front, back, left, or right) of the vertically positioned utility pole and the hole for pole installation are misaligned, the boom 13 can be extended and retracted and rotated to move the utility pole horizontally (front, back, left, or right) while maintaining its vertical position, thereby positioning the utility pole directly above the hole for pole installation.

[0059] Next, in order to move the vertically positioned utility pole vertically downward toward the pole installation hole, the mode selection switch 33 is operated to switch from the normal mode to the gripping part vertical operation mode. As shown in Figure 16(A), when the gripping part 81 is gripping the vertically positioned utility pole, a load corresponding to the weight of the utility pole acts downward on the gripping part 81. Subsequently, after switching the mode selection switch 33 to the gripping part vertical operation mode, the luffing and raising operation of the boom 13 and the vertical swing operation of the gripping part 81 are linked in response to the operation of the boom slewing and luffing operation lever 32a, and the gripping part 81 is moved vertically downward, thereby inserting the utility pole gripped by the gripping part 81 into the pole installation hole. As the gripping part 81 is moved vertically downward, when the lower end of the utility pole gripped by the gripping part 81 comes into contact with the bottom of the pole installation hole, the gripping part 81 receives a ground reaction force (a force that pushes the utility pole upward) from the bottom of the hole via the utility pole. As a result, as shown in Figure 16(B), the load acting on the gripping part 81 reverses from downward to upward. At this time, the load determination unit 106 of the controller 100 outputs a restriction signal to the operation control unit 102 when the load acting on the gripping part 81 becomes 0, stopping the vertical downward movement of the gripping part 102. As a result, the vertical downward movement of the gripping part 81 (utility pole) is stopped the moment the lower end of the utility pole contacts the bottom of the pole mounting hole, and the utility pole is positioned relative to the pole mounting hole. After inserting the utility pole to the bottom of the pole mounting hole in this manner, the lower end of the utility pole can be embedded and compacted in the pole mounting hole by filling the gap between the utility pole and the pole mounting hole with soil or other materials (by backfilling with excavated soil or crushed stones). This completes the pole mounting work of installing the utility pole in the pole mounting hole.

[0060] [3. Column Removal Work] Next, we will explain the pole removal operation (automatic pole removal operation) of the gripping-type hole-digging pole-erecting vehicle 1. Figures 17 to 19 are schematic diagrams showing the flow of the automatic pole removal operation.

[0061] First, in order to perform the automatic pole removal work, as shown in Figure 17(A), the pole removal machine 40 is set up near the base of the existing utility pole to be removed (indicated by the symbol "P" in Figures 17 to 19) as preliminary work. The chain 45 of the pole removal machine 40 is wrapped around the utility pole several times, and both ends of the chain 45 are locked to the upper end of the pole removal machine cylinder 41. In addition, the hydraulic hoses 46 and 47 (see Figure 10) of the pole removal machine cylinder 41 are connected to the hydraulic outlet of the vehicle, and the pole removal machine cylinder 42 is connected to the electromagnetic proportional control valve V10. Then, the operating device 31 is operated to move the gripping part 81 to the vicinity of the center of gravity of the utility pole, and then the gripping part 81 is operated in the closing direction to grip the center of gravity of the utility pole. This completes the preliminary work preparation.

[0062] After completing the preliminary preparations for the work, the worker turns on the automatic pole removal switch 35 of the operating device 31. This causes the automatic pole removal control unit 107 of the controller 100 to start the automatic pole removal operation according to a pre-stored automatic pole removal program. First, upon receiving the operation signal from the automatic pole removal switch 35, the automatic pole removal control unit 107 outputs a command signal to the operation control unit 102, causing the gripper cylinder 99 to extend and the gripping section 81 (gripping claws 82) to open. The gripper cylinder 99 is activated. As a result, the gripper portion 81's grip on the utility pole is temporarily loosened, as shown in Figure 17(B). This opening operation (release operation) of the gripper portion 81 is performed by moving a pair of gripping claws 82 away from each other to the extent that the utility pole does not detach from the gripper portion 81, thereby weakening the gripping force of the gripper portion 81 on the utility pole (a small gap may be left between the gripping claws 82 and the utility pole at this time). This opening operation of the gripper portion 81 (extension operation of the gripper cylinder 99) is performed until the pressure detected by the gripper cylinder pressure detector 126 (pressure in the bottom oil chamber of the gripper cylinder 99) falls below the second threshold pressure.

[0063] Next, the automatic pole removal control unit 107 outputs a command signal to the operation control unit 102, causing the pole removal machine cylinder 41 to extend, as shown in Figure 17(C). By extending the pole removal machine cylinder 41, the chain 45 of the pole removal machine 40 becomes taut (tightening the pole), and the pole is pulled out of the ground in response to the extension of the pole removal machine cylinder 41.

[0064] Next, the automatic pole removal control unit 107 determines whether the pole removal machine cylinder 41 has reached its fully extended state (stroke end in the extension direction). Based on the detection information from the pole removal machine cylinder pressure detector 127, the automatic pole removal control unit 107 determines that the pole removal machine cylinder 41 has reached its stroke end in the extension direction (fully extended state) when the pressure in the bottom oil chamber of the pole removal machine cylinder 41 exceeds a predetermined pressure (maximum pressure). When the automatic pole removal control unit 107 determines that the pole removal machine cylinder 41 has reached its fully extended state (stroke end in the extension direction), it outputs a command signal to the operation control unit 102, stopping the extension operation of the pole removal machine cylinder 41 and holding the pole removal machine cylinder 41 in the fully extended state for a predetermined time (for example, 1 second), as shown in Figure 18(D).

[0065] Next, the automatic pole removal control unit 107 outputs a command signal to the operation control unit 102, causing the gripper cylinder 99 to retract and the gripping part 81 (gripping claws 82) to operate in the closing direction. As a result, the utility pole is gripped by the gripping part 81, as shown in Figure 18(E). This closing operation of the gripping part 82 (retraction operation of the gripper cylinder 99) is performed until the pressure detected by the gripper cylinder pressure detector 126 (pressure in the bottom oil chamber of the gripper cylinder 99) becomes equal to or greater than the first threshold pressure (it is performed until the gripping force of the gripping part 81 reaches a specified gripping force).

[0066] Next, the automatic pole removal control unit 107 outputs a command signal to the operation control unit 102 to retract the pole removal machine cylinder 41, as shown in Figure 18(F). By retracting the pole removal machine cylinder 41, the tension of the chain 45 is gradually released, and the pole removal machine cylinder 41 can be retracted while the pole is held in place by the gripping part 81 (in a state where the pole is held so as not to fall).

[0067] Next, the automatic pole removal control unit 107 determines whether the pole removal machine cylinder 41 has reached its fully retracted state (stroke end in the retraction direction). Based on the detection information from the pole removal machine cylinder pressure detector 128, the automatic pole removal control unit 107 determines that the pole removal machine cylinder 41 has reached its fully retracted state (stroke end in the retraction direction) when the pressure in the rod-side oil chamber of the pole removal machine cylinder 41 exceeds a predetermined pressure (maximum pressure). If the automatic pole removal control unit 107 determines that the pole removal machine cylinder 41 has reached its fully retracted state (stroke end in the retraction direction), it outputs a command signal to the operation control unit 102, stopping the retraction operation of the pole removal machine cylinder 41 as shown in Figure 19(G), and holding the pole removal machine cylinder 41 in the fully retracted state. Then, if the worker confirms that the base of the utility pole is loose, the automatic pole removal operation ends when the automatic pole removal switch 35 of the operating device 31 is turned off, completing one cycle of the operations up to this point.

[0068] Once the automatic pole removal operation is complete, remove the pole removal machine 40 from the utility pole as shown in Figure 19(H). Next, as shown in Figure 19(I), the operator operates the control device 31 to appropriately activate the boom 13 and gripping device 50, moving the gripping part 81 upward. This lifts the utility pole, which is gripped by the gripping part 81, out of the pole-mounting hole and moves it to a predetermined location. After lowering the utility pole at the predetermined location, the gripping claws 82 are operated in the opening direction, releasing the gripping part 81 from the utility pole, and the utility pole can be placed in the predetermined location.

[0069] Although not shown in the diagram, if the automatic pole removal switch 35 is not switched from on to off within a predetermined time (for example, 10 seconds) after the completion of the first cycle of the automatic pole removal operation, the second cycle of the automatic pole removal operation will start (if the automatic pole removal switch 35 is not switched from on to off, the operation can continue for a third cycle and beyond). In other words, if the utility pole cannot be pulled out in only one cycle of the automatic pole removal operation (if the base of the utility pole does not loosen), if the automatic pole removal switch 35 is left on, the second and subsequent cycles of the automatic pole removal operation will start automatically (the automatic pole removal operation will be automatically repeated). In the second and subsequent cycles of this automatic pole removal operation, in order to prevent the utility pole to be removed from falling from the gripping part 81, the gripping part 81 is held in a closed state until the detected pressure of the pole removal machine cylinder pressure detector 127 (pressure in the bottom oil chamber of the pole removal machine cylinder 41) reaches a predetermined value, and when the detected pressure reaches the predetermined value, the gripping part 81 is operated in the open direction. In other words, in the first cycle of the aforementioned automatic pole removal operation, the extension operation of the pole removal machine cylinder 41 was started after the gripping part 81 was operated in the opening direction (after the gripping part 81 released its grip). However, in this second cycle, the extension operation of the pole removal machine cylinder 41 is started first, and after the pressure detected by the pole removal machine cylinder pressure detector 127 reaches a predetermined value, the gripping part 81 is operated in the opening direction (releasing its grip) to prevent the utility pole from falling during the removal process.

[0070] In summary, the main effects achieved in this embodiment are as follows.

[0071] First, according to this embodiment, if the auger screw 25 tilts forward, backward, left, or right beyond the allowable angle with respect to the vertical, the operation of the boom 13 and the operation of the auger screw 25 can be restricted, and the excavation work of the auger screw 25 can be automatically stopped. This makes it possible to prevent the hole for erecting the utility pole from being formed at an angle with respect to the vertical.

[0072] Furthermore, according to this embodiment, when moving the gripping portion 81 downwards to insert the utility pole gripped by the gripping portion 81 into a pole-mounting hole (a hole for erecting a columnar object), if the load acting on the gripping portion 81 drops below a threshold load, it is determined that the lower end of the utility pole has come into contact with the bottom of the pole-mounting hole, and the downward movement of the gripping portion 81 (utility pole) is automatically stopped. This prevents the worker from continuing to move the gripping portion 81 downwards without noticing that the lower end of the utility pole has come into contact with the bottom of the hole (resulting in the lower end of the utility pole being excessively pressed against the bottom of the hole), thereby preventing excessive load from being applied to the gripping portion 81 or the utility pole and causing damage.

[0073] Furthermore, according to this embodiment, when the automatic vertical switch 34 is operated, the vertical swivel cylinder 62 and gripper motor 79 are activated according to the inclination angle of the gripping part 81 with respect to the horizontal plane detected by the gripping part inclination angle detector 124 to change the posture of the gripping part 81. As a result, the utility pole gripped by the gripping part 81 can be made to a vertical position along the vertical direction. Therefore, even on sloping ground such as in mountainous areas, the utility pole gripped by the gripping part 81 can be automatically made to a vertical position without requiring skilled operating techniques, dramatically improving the work efficiency of pole erection work.

[0074] Furthermore, in this embodiment, only if the angle of inclination of the gripping portion 81 with respect to the horizontal plane detected by the gripping portion inclination angle detector 124 is within a predetermined angle, the utility pole gripped by the gripping portion 81 is not considered to be gripped by the gripping portion 81. Because control is performed to set the gripping part 81 to a vertical position, the range of motion required to change the gripping part 81 to a vertical position can be limited, preventing the utility pole from interfering with surrounding structures or the ground, or coming into contact with workers, thereby ensuring safety during work.

[0075] Furthermore, according to this embodiment, there is no need to use large heavy machinery such as a crane to lift the utility pole to be removed. The gripping device 50 of this gripping-type hole-digging pole-erecting vehicle 1 can be used to appropriately switch between gripping and releasing (releasing the grip) the utility pole to be removed, allowing the pole removal work to be performed by the pole removal machine 40. As a result, different types of work (pole erection work and pole removal work) can be performed with a single gripping-type hole-digging pole-erecting vehicle 1, expanding the applications of the gripping device 50 and further increasing the added value of this gripping-type hole-digging pole-erecting vehicle 1.

[0076] Furthermore, in this embodiment, a series of pole removal operations can be performed automatically and continuously by linking the opening and closing operation of the gripping part 31 with the extension and retraction operation of the pole removal machine 40. This reduces the effort and burden on the worker, thereby improving the efficiency and safety of the pole removal work.

[0077] Furthermore, in this embodiment, even if the utility pole cannot be pulled out in a single extension / retraction operation of the pole removal machine 40, the pole removal machine 40 can be automatically and continuously extended / retracted multiple times in response to the operation of the automatic pole removal switch 35, thereby further improving the work efficiency of the pole removal operation.

[0078] It should be noted that the present invention is not limited to the embodiments described above, and can be appropriately improved without departing from the spirit of the invention.

[0079] In the above embodiment, the gripping load detector 125 is configured as a pin-type load cell that detects the load acting on the connecting pin 63. However, the configuration is not limited to this, and for example, the gripping load detector 125 may be configured as a pressure detector that detects the pressure of the hydraulic fluid supplied to the bottom-side oil chamber and / or rod-side oil chamber of the vertical oscillating cylinder 62.

[0080] In the above embodiment, the gripping force of the gripping portion 81 (the force with which the gripping claws 82 grip the object) is indirectly detected based on the pressure in the bottom oil chamber of the gripper cylinder 99. However, the configuration is not limited to this, and for example, the gripping force of the gripping portion 81 may be directly detected by providing a load cell or strain gauge inside the gripping claws 82.

[0081] In the above embodiment, the stroke end in the extension and retraction direction of the column removal machine cylinder 41 was detected by the pressure in the bottom-side oil chamber and the rod-side oil chamber of the column removal machine cylinder 41. However, the configuration is not limited to this, and for example, it may be configured by a stroke detector that detects the position (stroke position) of the piston rod 43 of the column removal machine cylinder 41 in the extension and retraction direction.

[0082] In the above embodiment, the operating device 31 is provided in the operating seat 30 on the vehicle body 2, but the 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).

[0083] Furthermore, while the above embodiment illustrates a PTO-driven hole-digging and pole-erecting vehicle that uses a PTO (power take-off) mechanism to extract engine power and drive a hydraulic pump, the configuration is not limited to this. An electric-driven (battery-driven) hole-digging and pole-erecting vehicle or a hybrid vehicle equipped with both, which selectively switches the power source, may also be used. [Explanation of Symbols]

[0084] 1 Grasping type hole digging pole erecting vehicle 2 car bodies 12 Turntable 13 Boom 20 Auger devices 22 Auger motor 25 Earth Auger 31 Operating device 33 Mode Selection Switch 34 Automatic Vertical Switch 35 Automatic pole removal switch 40 Post removal machine 41 Pole Removal Machine Cylinder 50 Gripping device 51 Arm 55 Arm Cylinder 60 First joint member 62 Vertical Swivel Cylinder 70 Second joint member 71. Swivel cylinder 79 Gripper Motor 80 Grippa 81 Gripping part 82 Gripping claw 99 Gripper Cylinder 100 controllers 101 Position calculation section 102 Operation Control Unit 103 Auger tilt determination unit 104 Grip determination section 105 Automatic Vertical Control Unit 106 Load judgment section 107 Automatic column removal control unit 123 Auger tilt angle detector 124 Gripping part tilt angle detector 125 Gripping part load detector 126 Gripper Cylinder Pressure Detector 127 Pole Removal Machine Cylinder Pressure Detector 128 Pole Removal Machine Cylinder Pressure Detector

Claims

1. a boom provided on the vehicle body so as to be capable of raising and lowering and extending; a gripping portion capable of gripping a columnar object; a support mechanism provided between the tip of the boom and the gripping part, which changes the attitude of the gripping part with respect to the tip of the boom; an operating device for operating the boom, the gripping portion, and the support mechanism; a load detector that detects a load acting on the gripping portion when the gripping portion is gripping a columnar object; an operation control unit that controls the operation of the boom, the gripping unit, and the support mechanism in response to an operation of the operation device; A control device for a gripping-type hole-digging pole-setting vehicle, characterized in that it is configured with an operation control unit that regulates the downward movement of the gripping part by the boom and the support mechanism when the load detected by the load detector drops below a predetermined threshold value when the operation control unit operates the boom and the support mechanism to move the gripping part holding a pillar-shaped object downward.

2. the operating device includes a gripper vertical actuation operating device that is operated to move the gripper in a vertical direction, the operation control unit controls the vertical movement of the gripper by linking the raising and lowering operation and the extension and contraction operation of the boom with the operation of the support mechanism in response to the operation of the gripper vertical operation operation device, The control device for a gripping-type hole-digging and pole-setting vehicle as described in claim 1, characterized in that the operation regulating unit regulates the vertical downward movement of the gripping unit by the boom and the support mechanism when the load detected by the load detector drops below the threshold value when the operation control unit operates the boom and the support mechanism to move the gripping unit gripping a pillar-shaped object vertically downward.

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