Holding type work vehicle

Abstract

To perform a work of erecting a utility pole into a pole building hole while accurately positioning it without lowering work efficiency.SOLUTION: The holding type hole digging and pole building vehicle comprises: a boom mounted on a vehicle body so as to rotate, rise and fall and expand; a holding portion; a support mechanism (an arm, etc.) changing an attitude of the holding portion relative to a tip of the boom; a plurality of actuators (a swivel motor 14, a telescopic cylinder 15, a lifting cylinder 16, etc.) operating the boom and the support mechanism; a boom hoisting angle detector 120 and a boom extension amount detector 121; an operation device (a boom rotation and hoisting operation lever 32a, a boom expansion and bending operation lever 32b) outputting a movement command to move the holding portion horizontally or vertically; a mode setting device; and a controller 100 controlling a horizontal or vertical movement of the holding portion in the set mode.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a gripping type working vehicle used for gripping pole-shaped objects such as utility poles and performing pole erection work. [Background technology]

[0002] As an example of a gripping type work vehicle, a gripping type pole hole digger vehicle is known, which includes a swivel table provided on a vehicle body so as to be freely rotatable, a boom provided on the swivel table 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 using the pole hole digger vehicle to excavate a pole hole in the ground, 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 to form a pole hole of a predetermined depth. After the excavation of the pole hole is completed, the auger device is lifted 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 with the utility pole being gripped, so that the utility pole can be directly erected into the excavated pole hole. A pole hole digger equipped with such a gripping device can perform a series of pole erection work more efficiently than when the pole is hoisted using a winch or crane, etc. Note that there are also work vehicles equipped only with a gripping device without an auger device, so these will be collectively referred to as a gripping type work vehicle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2-81892 Summary of the Invention [Problem to be solved by the invention]

[0004] When such a gripping work vehicle is used to erect a pole, the pole is gripped by the gripping device provided at the end of the boom as described above, the boom is operated while gripping the pole, the gripped pole is transported to the top of the excavated pole hole, and the pole is erected in the pole hole. At this time, control in a horizontal / vertical movement mode may be performed in which the gripping device at the end of the boom is moved horizontally and vertically by combining the boom's rotation, hoisting, and telescopic movements. In the vertical movement mode, the position of the boom's tip (the gripping device position) is found based on the detection values ​​from the boom's hoisting angle detection sensor and extension amount detection sensor, and the hoisting and telescopic movements are controlled so that the boom's tip position (the gripping device position) moves along a target movement line extending vertically. In the horizontal movement mode, the position of the boom tip (position of the gripping device) is calculated based on the detection values ​​from the boom swivel angle detection sensor as well as the detection values ​​from the boom hoist angle detection sensor and extension amount detection sensor, if necessary, and the swing, hoisting and telescopic movement controls are combined so that the boom tip position (position of the gripping device) moves along a target movement line set in the horizontal direction. Note that there is also a control for moving the boom tip horizontally within the boom hoisting plane, in which case the boom hoisting and telescopic movement controls are combined.

[0005] In this case, there is a problem that the actual movement trajectory of the boom tip varies (fluctuates) from the target movement line due to factors such as the detection accuracy of the sensor, the response delay of the boom operation control to the sensor detection value, the boom operation response delay, etc. In particular, the boom is rotated, raised and retracted by driving, for example, a hydraulic motor for rotation, a hydraulic cylinder for raising and lowering, and a hydraulic cylinder for retracting, and the supply of hydraulic oil to these hydraulic motors and hydraulic cylinders is controlled by a hydraulic control valve. Since the hydraulic motor and hydraulic cylinder are controlled by the hydraulic actuator, it is practically unavoidable that there will be a delay in the hydraulic response to the hydraulic motor and hydraulic cylinder operation command. Also, the detection accuracy of the sensor detection value is not good and detection errors are unavoidable, which inevitably leads to a decrease in electrical control accuracy. Since there is a problem in that the actual movement trajectory of the boom tip (gripping device) varies (fluctuations) from the target movement line, in the horizontal and vertical movement mode control, a variation tolerance area is set that extends cylindrically around the target movement line, and the variation (fluctuation) of the actual movement trajectory within this variation tolerance area is tolerated.

[0006] The problem of the actual movement trajectory varying (fluctuation) from the target movement line is caused by a delay in the response of the boom operation control to the sensor detection value and a delay in the operation response to the operation command of the hydraulic motor and hydraulic cylinder, and is therefore affected by the speed at which the tip of the boom is moved horizontally and vertically. Specifically, if the tip of the boom is controlled to move horizontally and vertically at a fast speed, the movement trajectory will vary (fluctuation) significantly from the target movement line, and if it is controlled to move horizontally and vertically at a slow speed, the variation (fluctuation) of the movement trajectory from the target movement line can be reduced. However, in reality, if the speed at which the tip of the boom is moved horizontally and vertically is slow, work efficiency decreases, so control is performed to set a certain amount of allowable fluctuation range and ensure the horizontal and vertical movement speed.

[0007] Incidentally, when a pole erection work is performed using a gripping work vehicle, the pole is gripped by the gripping part attached to the tip of the boom, and while gripping the pole, the tip of the boom (the gripping part) is moved horizontally to transport the gripped pole above the excavated pole hole, and the gripping attitude is changed so that the pole extends vertically, and then the pole is erected into the pole hole. At this time, since the difference between the diameter of the pole hole (approximately 450 mm) and the diameter of the pole to be inserted into the pole hole (approximately 390 mm) is small, if the allowable range of variation in the control in the horizontal and vertical movement modes is larger than this difference, there is a problem that the position of the pole will deviate greatly from the position of the pole hole, making it difficult to erect the pole into the pole hole.

[0008] The present invention has been made in consideration of such problems, and aims to provide a gripping type work vehicle that can grip a column-shaped object such as a utility pole, transport it to the top of a pole hole, and insert the utility pole into the pole hole without reducing work efficiency and by accurately positioning the pole. [Means for solving the problem]

[0009] In order to achieve the above-mentioned objective, the gripping type work vehicle of the present invention (for example, the gripping type hole digging pole construction vehicle 1 in the embodiments) is configured to include a vehicle body, a boom (for example, the boom 13 in the embodiments) that is mounted on the vehicle body so as to be capable of rotating, raising and lowering and extending, a gripping section (for example, the gripper 80 and gripping section 81 in the embodiments) capable of gripping an object to be gripped, and a support mechanism (for example, the arm 51, first joint member 60, and second joint member 70 in the embodiments) that is provided between the tip of the boom and the gripping section and changes the attitude of the gripping section relative to the tip of the boom. This grip-type work vehicle includes a plurality of actuators (for example, the swing motor 14, telescopic cylinder 15, hoisting cylinder 16, arm cylinder 55, vertical swing cylinder 62, horizontal swing cylinder 71, and gripper motor 79 in the embodiments) that operate the boom and the support mechanism, a boom hoist angle detector (for example, the boom hoist angle detector 120 in the embodiments) that detects the boom hoist angle and a boom extension amount detector (for example, the boom extension amount detector 121 in the embodiments) that detects the extension length of the boom, an operation device (for example, the boom swing / hoisting operation lever 32a and the boom extension / retraction operation lever 32b in the embodiments) that outputs a movement command for moving the grip part horizontally or vertically in response to an operation, a mode setting device (for example, the mode selection switch 33 in the embodiments) that can select and set a movement speed command mode or a movement accuracy improvement mode as a mode for moving the grip part horizontally or vertically based on the movement command from the operation device, and a control device (for example, the control device 32) that can select and set the movement speed command mode and the movement accuracy improvement mode as a mode for moving the grip part horizontally or vertically based on the movement command from the operation device. and a control device that, when a movement speed command mode is set, moves the gripping part horizontally or vertically under the movement speed command mode based on the movement command from the operation device, and, when the movement accuracy improvement mode is set by the mode setting device, controls the gripping part to move horizontally or vertically under the movement accuracy improvement mode based on the movement command from the operation device. In the movement speed command mode, the control of moving the gripper unit horizontally or vertically by the control device is performed by decomposing a target horizontal movement direction and a target horizontal movement speed, or a target vertical movement direction and a target vertical movement speed, of the gripper unit obtained in response to the movement command from the operating device into operations of raising and lowering and retracting the boom to obtain a target hoisting direction and a target hoisting speed, and a target telescopic direction and a target telescopic speed, and by combining control of raising and lowering the boom in the target hoisting direction and the target hoisting speed and control of telescopically retracting the boom in the target telescopic direction and the target telescopic speed, the position of the gripper unit is obtained from values ​​detected by the boom hoisting angle detector and the boom extension amount detector, and the gripper unit whose position has been obtained in this manner is moved in the target horizontal movement direction. Alternatively, the control unit is configured to control the target boom hoisting speed and target boom extension speed while correcting the target boom hoisting speed and target boom extension speed so that the gripper moves toward the target vertical movement direction at the target horizontal movement speed or the target vertical movement speed, and in the movement accuracy improvement mode, the control unit controls the vertical movement of the gripper by controlling the boom to be raised or lowered in response to the operation of the operating device based on a vertical movement command from the operating device, and also controls the boom to be extended or lowered so that the gripper moves vertically in this manner in response to the boom being raised or lowered, and determines the position of the gripper from values ​​detected by the boom hoisting angle detector and the boom extension amount detector, and controls to correct the target boom extension speed so that the gripper, the position of which is determined in this manner, moves vertically.

[0010] In the grip-type work vehicle, the control device is preferably configured to also control the horizontal movement of the gripper in the movement accuracy improvement mode, and the control of the horizontal movement involves controlling the boom to extend and retract based on a horizontal movement command from the operating device, and also controlling the boom to be raised and lowered so that the gripper moves horizontally in response to the boom being extended and retracted, determining the position of the gripper from values ​​detected by the boom hoisting angle detector and the boom extension amount detector, and controlling to correct the target boom hoisting speed so that the gripper whose position has been determined in this manner moves horizontally.

[0011] In the gripping-type work vehicle, preferably, the object to be gripped is a pillar-shaped object such as a utility pole, and when the pillar-shaped object is gripped by the gripping section, a pillar-shaped object gripping angle detector is provided which detects the angle of the extension direction of the pillar relative to the gripping section, and the control device is capable of automatically switching between control in the movement speed command mode and control in the movement accuracy improvement mode using the angle detected by the pillar-shaped object gripping angle detector as the specified condition.

[0012] In the gripping type work vehicle, preferably, the gripping section has a pair of opening and closing gripping claws for gripping the pillar-shaped object, the support mechanism has a rotation mechanism for rotating the gripping claws around a rotation axis perpendicular to the opening and closing direction, and the gripping claws can be rotated by the rotation mechanism to adjust the angle at which the pillar-shaped object gripped by the gripping claws is held, the pillar gripping angle detection is capable of detecting the angle at which the pillar-shaped object gripped by the gripping claws is held, and the control device is capable of automatically switching between control in the movement speed command mode and control in the movement accuracy improvement mode, using the angle detected by the pillar gripping angle detection as the specified condition.

[0013] In the grip-type working vehicle, preferably, the control device switches to the control in the movement accuracy improvement mode when it is detected by the column gripping angle detection that the column gripped by the gripping unit is extended and held at an angle within a predetermined angle range including a vertical direction, When it is detected by the column gripping angle detection that the column gripped by the gripping portion is extended and held at an angle outside the predetermined angle range, control is switched to the movement speed command mode. Effect of the Invention

[0014] According to the grip-type working vehicle of the present invention, in the movement speed command mode, the control of moving the gripper unit horizontally or vertically by the control device is carried out by determining a target horizontal movement direction and a target horizontal movement speed, or a target vertical movement direction and a target vertical movement speed, of the gripper unit obtained in response to the movement command from the operating device into the operation of raising and lowering the boom to obtain a target raising and lowering direction and a target raising and lowering speed, and a control of raising and lowering the boom in the target raising and lowering direction and the target raising and lowering speed. The position of the gripper is determined from the detection values ​​by the boom hoisting angle detector and the boom extension amount detector while combining these controls to extend and retract the boom, and the target boom hoisting speed and target extension / retraction speed of the boom are corrected and controlled so that the gripper, whose position has been determined in this manner, moves in the target horizontal movement direction or the target vertical movement direction at the target horizontal movement speed or the target vertical movement speed.As a result, it is possible to control the gripper to move at a constant speed that corresponds to the operation of the operating device, and an object gripped by the gripper can be transported at the desired constant speed.

[0015] On the other hand, in the movement accuracy improvement mode, the control of vertical movement of the gripping part by the control device is based on a vertical movement command from the operating device, and controls the boom to be raised and lowered in response to the operation of the operating device, and also controls the boom to be extended and retracted so that the gripping part moves vertically in response to the raising and lowering of the boom, determines the position of the gripping part from the detection values ​​by the boom hoisting angle detector and the boom extension amount detector, and controls to correct the target extension and retraction speed of the boom so that the gripping part whose position has been determined moves vertically. Since the boom is raised and lowered in response to the operation and movement control only controls the extension and retraction of the boom to move vertically in response to this, accurate vertical movement control is possible. Therefore, for example, when the utility pole is held by the gripping part so that it extends vertically and the work of inserting the utility pole into a pole hole is performed, accurate control in the improved movement accuracy mode is possible, so that the pole erection work can be performed accurately and easily even if the difference between the diameter of the pole hole (approximately 450 mm) and the diameter of the utility pole (approximately 390 mm) is small.

[0016] The control device is preferably configured to also perform control to horizontally move the gripper in the movement accuracy improvement mode, and the control to horizontally move the gripper includes control to extend and retract the boom based on a horizontal movement command from the operating device, and control to raise and lower the boom so that the gripper moves horizontally in response to the extension and contraction of the boom, and to determine the position of the gripper from values ​​detected by the boom hoist angle detector and the boom extension amount detector, and to control to correct the target boom hoisting speed so that the gripper whose position has been determined moves horizontally. With this configuration, the boom is extended and retracted in response to operation, and movement control is performed to control only the raising and lowering of the boom to move horizontally in response to the extension and contraction of the boom, making it possible to perform accurate horizontal movement control.

[0017] It is preferable that the object to be gripped is a columnar object such as a utility pole, and that a columnar object gripping angle detector is provided for detecting an angle of the extending direction of the columnar object relative to the gripping portion when the columnar object is gripped by the gripping portion, and that the control device is capable of automatically switching between the control in the movement speed command mode and the control in the movement accuracy improvement mode using the angle detected by the columnar object gripping angle detector as the predetermined condition. The switching between the control in the movement speed command mode and the control in the movement accuracy improvement mode is required to be performed according to the posture of the object gripped by the gripping portion. In such a case, it is possible to appropriately switch between the control in the movement speed command mode and the control in the movement accuracy improvement mode.

[0018] Furthermore, in this case, it is preferable that the gripping unit has a pair of gripping claws that can be opened and closed to grip the columnar object, the support mechanism has a rotation mechanism that rotates the gripping claws around a rotation axis perpendicular to the opening and closing direction, and the gripping claws can be rotated by the rotation mechanism to adjust the angle at which the columnar object gripped by the gripping claws is held, the columnar object gripping angle detection can detect the angle at which the columnar object gripped by the gripping claws is held, and the control device can automatically switch between the control in the movement speed command mode and the control in the movement accuracy improvement mode using the angle detected by the columnar object gripping angle detection as the predetermined condition. This makes it possible to accurately switch between the control in the movement speed command mode and the control in the movement accuracy improvement mode according to the holding angle of the columnar object gripped by the gripping unit. For example, in pole erection work, a utility pole (pillar-shaped object) may be grasped in a horizontally extended state and moved horizontally (transported movement in the horizontal direction), and then moved vertically above the pole erection hole, where it is then moved vertically. In such cases, it is possible to accurately switch between control in the movement speed command mode and control in the movement accuracy improvement mode.

[0019] In this case, it is preferable that the control device switches to the control in the movement accuracy improvement mode when it is detected by the column gripping angle detection that the column gripped by the gripping unit is extended and held at an angle within a predetermined angle range including the vertical direction, and switches to the control in the movement speed command mode when it is detected by the column gripping angle detection that the column gripped by the gripping unit is extended and held at an angle outside the predetermined angle range. This makes it possible to accurately switch in pole erection work between gripping a utility pole (column) in a horizontally extended state and moving it horizontally (transporting movement in the horizontal direction) and then moving it vertically above the pole erection hole. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a side view of a gripping-type pole hole digging vehicle which is a specific embodiment of the gripping-type work vehicle according to the present invention. [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] FIG. 2 is an oblique view of an auger device provided on the above-mentioned grip-type hole digging pole construction vehicle. [Diagram 5] This is an oblique view of a gripping device provided on the above-mentioned gripping-type hole digging pole construction vehicle. [Figure 6] FIG. 2 is a perspective view of a main part of the gripping device as viewed from the right. [Figure 7] FIG. 2 is a perspective view of a main part of the gripping device as viewed from the left. [Figure 8] FIG. 2 is a cross-sectional view of the gripping device. [Figure 9] FIG. 2 is a vertical cross-sectional view of the gripping device. [Figure 10] FIG. 2 is a functional block diagram of the above-mentioned gripping-type pole hole digging vehicle. [Figure 11] FIG. 2 is a schematic diagram showing a mode selection switch. [Figure 12] 11 is an explanatory diagram showing control when moving a gripping portion of the gripping device in a horizontal direction. FIG. [Figure 13]11 is an explanatory diagram showing control when moving a gripping portion of the gripping device vertically downward. FIG. [Figure 14] 5A to 5C are schematic diagrams for explaining the operation of the gripping unit of the gripping device in a horizontal position. [Figure 15] FIG. 2 is a schematic explanatory diagram showing the process of gripping a utility pole with the gripping device of the gripping-type hole digging pole installation vehicle to perform pole installation work. [Figure 16] FIG. 2 is a schematic explanatory diagram showing the process of gripping a utility pole with the gripping device of the gripping-type hole digging pole installation vehicle to perform pole installation work. [Figure 17] FIG. 2 is a schematic explanatory diagram showing the process of gripping a utility pole with the gripping device of the gripping-type hole digging pole installation vehicle to perform pole installation work. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. First, the overall configuration of a grip-type hole digging pole erection vehicle 1 as a specific embodiment of a grip-type working vehicle according to the present invention will be described with reference to Figs. 1 to 3.

[0022] 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.

[0023] A swivel base 12 that is driven by a swivel motor 14 (see FIG. 10) and configured to be horizontally rotatable about a vertical axis is provided in a mounting area behind the driver's cabin 7 in the vehicle body 2. The base end of a boom 13 is attached to the swivel base 12 so as to be vertically swingable (raised and lowered).

[0024] 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 the extension and retraction of a telescopic cylinder 15 (see FIG. 10) provided inside. In addition, 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 up-down plane (vertical plane).

[0025] An auger support 17 that can be selectively connected to the base boom 13a and the tip boom 13c is attached to the boom 13. As shown in FIG. 4, an upper shaft portion 27a of a connecting rod member 27 is pivotally connected to the auger support 17 so as to be swingable in the left-right direction. An auger device 20 for drilling a post hole is pivotally connected to a lower shaft portion 27b of the connecting rod member 27 so as to be swingable in the front-rear direction. This allows the auger device 20 to be suspended from the auger support 17 so as to be swingable in the front-rear and left-right directions. The auger device 20 is configured to include an auger motor portion 21 pivotally connected to the lower shaft portion 27b of the connecting rod member 27, and an auger screw (earth auger) 25 that is rotated about its axis by operating the auger motor portion 21. The auger motor section 21 has an auger motor 22 that is rotated by hydraulic pressure, 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 an upper end of an auger screw 25 is connected to this drive shaft.

[0026] An auger storage device 18 is disposed on the side of the base boom 13a, which holds the auger device 20 in a stored state with the auger support 17 connected to the base boom 13a. The auger device 20 is attached to the auger support 17 via a connecting rod member 27 so as to be swingable up and down in 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 (the auger support 17 is connected to the tip boom 13c) and the auger screw 25 is lowered toward the ground. When in the working position, the auger device 20 is fixed to the tip of the boom 13 via the connecting rod member 27 so that the auger screw 25 takes a vertical position along the direction of gravity (vertical direction) regardless of the attitude of the boom 13. The material 27 is suspended about both shaft portions 27a, 27b as fulcrums so as to be swingable in the front-rear and left-right directions.

[0027] 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 auger screw 25 is in a substantially vertical position relative to the ground), and the auger screw 25 is rotated by the rotational drive of the auger motor 22 while the boom 13 is moved downward linearly in conjunction with the lowering and retracting movements, thereby enabling the excavation of a post hole. On the other hand, when the auger device 20 is not used, as shown in FIGS. 1 and 2, the auger support 17 is connected to the base boom 13a, and the auger device 20 is stored and held by the auger storage device 18 in a storage position along the side of the base boom 13a. When the auger device 20 is in the storage position, various operations such as pole erection and removal of utility poles (indicated by the symbol P in FIG. 3: the same applies below) and relocation of obstacles can be performed using the gripping device 50, as shown in II of FIG. 3, which will be described later.

[0028] An arm bracket 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 or a tree is attached to the arm bracket 19. The configuration of the gripping device 50 will be described with additional reference to Figs. 5 to 9. Note that hatching showing cross sections has been omitted in Figs. 8 and 9 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, respectively, with the attitude of the gripping device 50 shown in Fig. 5 as the reference.

[0029] The gripping device 50 is configured to include an arm 51 attached to the arm bracket 19 so as to be able to swing (bend and extend) in the vertical direction, a first joint member 60 attached to the tip of the arm 51 so as to be able to swing (pivot) in the vertical direction, a second joint member 70 attached to the first joint member 60 so as to be able to swing (pivot) in the left-right direction, and a gripper 80 rotatably attached to the second joint member 70. The posture of a gripping portion 81 of the gripper 80 can be changed by the arm 51, the first joint member 60, the second joint member 70, a vertical swing cylinder 62 described below, a horizontal swing cylinder 71, a gripper motor 79, and the like, and this mechanism is referred to as a support mechanism.

[0030] One end of the arm 51 in the axial direction (longitudinal direction) is pivotally connected to the arm bracket 19 via a connecting pin 52, and the other end of the arm 51 in the axial direction (longitudinal direction) is pivotally connected to a first joint member 60 via a connecting pin 53. An arm cylinder 55 is attached between the arm bracket 19 and the arm 51. A rod side end of the arm cylinder 55 is pivotally connected to the arm bracket 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 extending and retracting the arm cylinder 55, the arm 51 can be swung (bent and extended) in the up and down direction around the connecting pin 52 relative to the arm bracket 19.

[0031] 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. By extending and retracting the vertical swivel cylinder 62, the first joint member 60 can be swung (vertically swivels) in the up and down direction relative to the arm 51 around the connecting pin 53.

[0032] The second joint member 70 is sandwiched between the first joint members 60 from above and below. The first joint member 60 is supported by a horizontal swivel cylinder 71. A bottom end of the horizontal swivel cylinder 71 is pivotally connected to the tip of the first joint member 60, and a rod end of the horizontal swivel cylinder 71 is pivotally connected to the rear end of the second joint member 70. By extending and contracting the horizontal swivel cylinder 71, the second joint member 70 can be swung (swivels) left and right relative to the first joint member 60 around the connecting pin 61.

[0033] The gripper 80 comprises 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.

[0034] 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 can grip various objects (pillar-shaped objects) such as utility poles 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 the tips can cross (overlap) each other. The support plate portion 83 is provided with a flat upper bracket 85 for detachably mounting an attachment (not shown) (for example, a tree felling device for felling trees).

[0035] The gripper housing 86 includes a support tube portion 87 connected to the upper and lower support plate portions 83 and supported rotatably by 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.

[0036] 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 X (see FIG. 8) via the worm pinion 91 and the worm wheel 90. On the other hand, when the gripper motor 79 is rotated in the reverse direction, the entire gripper 80 rotates about the rotation axis X (see FIG. 8) in the opposite direction to the predetermined direction via the worm pinion 91 and the worm wheel 90. In the posture of the gripping device 50 shown in FIG. 5, the direction of the rotation axis X 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.

[0037] 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 for sliding 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 part of the sliding member 95 via a connecting pin 97 with the other ends of each link member 94 overlapping each other vertically. The sliding member 95 is inserted into the hollow part of the inner cylindrical part 88 and is attached so as to be slidable (reciprocating) along the inner peripheral surface of the inner cylindrical part 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 part 88 to guide the sliding (reciprocating movement) of the sliding member 95. The rod side end of the gripper cylinder 99 is attached 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.

[0038] 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)), thereby enabling the gripping of the object to be released. On the other hand, when the gripper cylinder 99 is contracted, 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)), thereby enabling the object to be gripped. The opening / closing mechanism 93 is configured symmetrically, so that the pair of gripping claws 82 open and close symmetrically.

[0039] An operator's seat 30 for operating each of the working devices (the swivel base 12, the boom 13, the auger device 20, and the gripping device 50) is provided on the side of the swivel base 12 of the vehicle body 2. In front of the operator's seat 30, an operating device 31 is provided that can be operated by an operator while in a seated position. The operating device 31 is provided with a boom rotation and hoisting operation lever 32a which is operated to rotate and raise and lower the boom 13, a boom extension and contraction operation lever 32b which is operated to extend and retract the boom 13 and bend and extend the arm 51, an auger operation lever 32c which is operated to rotate the auger screw 25, a gripper vertical swing operation lever 32d which is operated to swing the gripper 81 vertically, a gripper horizontal swing operation lever 32e which is operated to swing the gripper 81 horizontally, a gripper rotation operation lever 32f which is operated to rotate the gripper 81, and a gripper opening and closing operation lever 32g which is operated to open and close the gripper 81 (see Figure 10). As will be described later, when a travel speed command or travel accuracy improvement mode is selected, the boom slewing / hoisting operation lever 32a functions as a vertical operation lever, and the boom telescopic / flexing / extending operation lever 32b functions as a horizontal operation lever. Of course, horizontal and vertical operation levers may be provided separately.

[0040] The operation device 31 is further provided with a mode selection switch 33 and an automatic vertical switch 34 as shown in FIG. 10. The mode selection switch 33 is a rotatably operated switch configured as shown in FIG. 11. By rotating the switch, the switch indicator 33a can be positioned to any of the following positions: normal operation mode NM, movement speed command mode SPM, movement accuracy improvement mode APM, and automatic switching mode AUTM, to select each mode. When any mode is selected by the mode selection switch 33, a command signal corresponding to the selected position is sent to the controller 100. The movement speed command mode SPM, movement accuracy improvement mode APM, and automatic switching mode AUTM are all control modes for moving the gripper 80 (gripping unit 81) horizontally or vertically in response to the operation of the boom rotation / hoisting operation lever 32a (vertical operation lever) and the boom extension / retraction operation lever 32b (horizontal operation lever).

[0041] Operation control in each mode is performed by the horizontal / vertical movement control section 107 of the controller 100, and specific details of the operation control will be described later. When the mode selection switch 33 is set to a position for the normal operation mode NM and the normal operation mode NM is selected, control is performed to operate the corresponding actuator in response to the operation of each operation lever. Specifically, the boom 13 is rotated and raised / lowered in response to the operation of the boom rotation / hoisting operation lever 32a, the boom 13 is extended / retracted and the arm 51 is extended / retracted in response to the operation of the boom extension / contraction / flexion operation lever 32b, the auger screw 25 is rotated in response to the operation of the auger operation lever 32c, the gripper 81 is swung vertically in response to the operation of the gripper vertical swing operation lever 32d, and the gripper 81 is swung horizontally in response to the operation of the gripper horizontal swing operation lever 32e. The actuators are controlled so that grip portion 81 rotates in response to the operation of grip portion rotation lever 32f, and grip portion 81 opens and closes in response to the operation of grip portion opening / closing lever 32g.

[0042] When any of the movement speed command mode SPM, movement accuracy improvement mode APM, and automatic changeover mode AUTM is set by operating the mode selection switch 33, the boom rotation and hoisting operation lever 32a functions as a vertical operation lever, and the boom extension / contraction operation lever 32b functions as a horizontal operation lever, and control is performed to move the gripper 80 (gripping portion 81) horizontally and vertically in response to the operation of these levers. Specifically, when the boom rotation and hoisting operation lever 32a is tilted forward (toward the rear), the gripper 80 (gripping portion 81) is moved vertically downward, and when the boom rotation and hoisting operation lever 32a is tilted backward (toward the near side), the gripper 80 (gripping portion 81) is moved vertically upward. On the other hand, when the boom telescopic bending / extension operation lever 32b is tilted forward (towards the back), the gripper 80 (gripping portion 81) is moved horizontally forward within the boom hoisting surface, and when the boom telescopic bending / extension operation lever 32b is tilted backward (towards the front), the gripper 80 (gripping portion 81) is moved horizontally backward within the boom hoisting surface.

[0043] Automatic vertical switch 34 is configured as a toggle switch that can be switched between an ON position and an OFF position (so that the switched operating position is maintained even if the operator releases his / her hand). When automatic vertical switch 34 is selected to the ON position, as will be described later in detail, vertical oscillating cylinder 62 and gripper motor 79 are operated to vertically oscillate and rotate gripper 81, thereby making gripper 81 assume a horizontal position (that is, a utility pole or the like held by gripper 81 can be held so as to extend vertically). Note that automatic vertical switch 34 is enabled (operation signal is enabled) when the inclination angle of gripper 81 with respect to the horizontal plane detected by gripper inclination angle detector 124 (see FIG. 10) described later is within a predetermined angle.

[0044] In order to operate the swivel base 12, boom 13, auger device 20, gripping device 50, etc., a controller 100 is provided that receives an operation signal from an operating device 31 and controls the operation of the swivel motor 14, telescopic cylinder 15, hoisting cylinder 16, auger motor 22, 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"), as shown in Fig. 10, and a hydraulic unit 110 is provided that supplies hydraulic oil for driving the hydraulic actuators. Note that in this embodiment, hydraulic actuators such as hydraulic cylinders and hydraulic motors are used, but electric actuators or the like may be used instead.

[0045] An operation signal output by operating 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).

[0046] The hydraulic unit 110 is configured to include 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 engine of the vehicle via a PTO mechanism (not shown). The control valves 112 include an electromagnetic proportional control valve V1 for controlling the operation of the swing motor 14, an electromagnetic proportional control valve V2 for controlling the operation of the telescopic cylinder 15, an electromagnetic proportional control valve V3 for controlling the operation of the hoisting cylinder 16, an electromagnetic proportional control valve V4 for controlling the operation of the auger motor 22, an electromagnetic proportional control valve V5 for controlling the operation of the arm cylinder 55, an electromagnetic proportional control valve V6 for controlling the operation of the vertical swing cylinder 62, an electromagnetic proportional control valve V7 for controlling the operation of the horizontal swing cylinder 71, an electromagnetic proportional control valve V8 for controlling the operation of the gripper motor 79, and an electromagnetic proportional control valve V9 for controlling the operation of the gripper cylinder 99. The control valve 112 electromagnetically controls the opening of each of the electromagnetic proportional control valves V1 to V9 based on a command signal from the controller 100, controls the supply direction and supply amount of hydraulic oil supplied from the hydraulic pump 111 to each hydraulic actuator, and controls the operating direction and operating speed of each hydraulic actuator (controls the operating direction and operating speed of the swivel base 12, boom 13, auger device 20, and gripping device 50).

[0047] The controller 100 is electrically connected to various detectors such as a boom hoisting angle detector 120, a boom extension amount detector 121, a boom rotation angle detector 122, and a grip portion inclination angle detector 124.

[0048] The boom hoisting angle detector 120 is provided inside the boom base end 13a and detects the hoisting angle of the boom 13. The boom extension amount detector 121 is provided at the base end of the boom base end 13a and detects the length (extension amount) 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).

[0049] The gripper inclination angle detector 124 is attached to the upper surface of the gripper 81 (support plate 83). The gripper inclination angle detector 124 is a two-axis inclination angle detector that detects the left-right inclination angle and the front-back inclination angle as the inclination angle of the gripper 81 with respect to the horizontal plane. The gripper inclination angle detector 124 detects the left-right inclination angle and the front-back inclination angle of the gripper 81, and outputs a voltage signal (detection signal) according to the detected inclination angle to the controller 100. Although not shown, an arm swing angle detector is provided that detects the up-down swing angle (bending and stretching angle) of the arm 51 with respect to the tip of the boom 13, and the detection signal is also output to the controller 100.

[0050] The controller 100 includes a position calculation unit 101 , an operation control unit 102 , a grip determination unit 104 , an automatic vertical control unit 105 , and a horizontal / vertical movement control unit 107 .

[0051] The position calculation unit 101 calculates the position of the tip of the boom 13 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 swing angle detector 122. The position calculation unit 101 further calculates the position of the gripper 80 (gripping portion 81) relative to the tip of the boom 13 based on detection information from the gripping portion inclination angle detector 124 and an arm swing angle detector (not shown) in addition to these pieces of detection information. Furthermore, the position calculation unit 101 also calculates the position of the gripper 80 (gripping portion 81) relative to the vehicle body 2.

[0052] When one of the normal operation mode NM, movement speed command mode SPM, movement accuracy improvement mode APM, and automatic switching mode AUTM is selected and set by operating the mode selection switch 33, the operation control unit 102, together with the horizontal / vertical movement control unit 107 as necessary, controls the operation of each actuator according to the operation signal (operation command) output from the operation device 31 according to each mode. Control in each mode will be described below.

[0053] (Normal operation mode NM) When the indicator 33a of the mode selection switch 33 is operated to the normal operation mode NM position and the normal operation mode NM is selected and set, the operation control section 102 operates each hydraulic actuator independently in response to the operation of each of the operation levers 32a-32g when the operation levers 32a-32g are operated. Specifically, when the boom rotation / hoisting operation lever 32a is tilted forward (front / back and left / right directions based on the operator operating the boom: the same applies below), the hoisting cylinder 16 is contracted to lower the boom 13, and when the boom rotation / hoisting operation lever 32a is tilted backward, the hoisting cylinder 16 is extended to raise or lower the boom 13. When the boom extension / flexion / extension operation lever 32b is tilted forward, the telescopic cylinder 15 is extended to extend the boom 13, and when ... When the boom slewing / hoisting operation lever 32a is tilted backward, the telescopic cylinder 15 is retracted to retract the boom 13. When the boom slewing / hoisting operation lever 32a is tilted leftward, the slewing motor 14 is rotated forward to rotate the boom 13 counterclockwise, and when the boom slewing / hoisting operation lever 32a is tilted rightward, the slewing motor 14 is rotated reverse to rotate the boom 13 clockwise.

[0054] When using the auger device 20, when the auger operating lever 32c is tilted forward, the auger motor 22 is rotated in the reverse direction to rotate the auger screw 25 in the reverse direction, and when the auger operating lever 32c is tilted backward, the auger motor 22 is rotated in the forward direction to rotate the auger screw 25 in the forward direction.

[0055] When the gripping device 50 is used, when the boom telescopic bending / extending operation lever 32b is tilted leftward, the arm cylinder 55 is extended to bend and extend the arm 51 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 contracted to bend and extend the arm 51 upward relative to the tip of the boom 13. When the gripper vertical swing operation lever 32d is tilted forward, the vertical swing cylinder 62 is extended to swing the gripper 81 downward (vertical swing), and when the gripper vertical swing operation lever 32d is tilted backward, the vertical swing cylinder 62 is contracted to swing the gripper 81 upward (vertical swing). 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), and when the gripper vertical swing operation lever 32e is tilted rightward, the horizontal swing cylinder 71 is contracted to swing the gripper 81 to the right (horizontal swing). When the gripper rotation operation lever 32f is tilted forward, the gripper motor 79 is rotated forward to rotate the gripper 81 clockwise, and when the gripper rotation operation lever 32f is tilted backward, the gripper motor 79 is rotated reversely to rotate the gripper 81 counterclockwise. When the gripping unit opening / closing operating lever 32g is tilted forward, the gripper cylinder 99 is contracted to operate the gripping unit 81 in the closing direction (in the direction to grip the 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 object).

[0056] (Speed ​​command mode SPM) When the indicator of the mode selection switch 33 is operated to the position of the movement speed command mode SPM and the movement speed command mode SPM is selected, the gripper 80 (gripping portion 81) is moved horizontally in response to the operation of the boom telescopic bending / extension operation lever 32b, which functions as a horizontal operation lever, and the gripper 80 (gripping portion 81) is moved vertically in response to the operation of the boom swing / hoisting operation lever 32a, which functions as a vertical operation lever. First, the control for moving the gripper 80 (gripping portion 81) horizontally in response to the operation of the boom telescopic bending / extension operation lever 32b will be described. When the boom swing / hoisting operation lever 32a is tilted forward (toward the rear), the gripper 80 (gripping portion 81) is moved horizontally forward in a straight line within the boom hoisting surface, and when the boom telescopic bending / extension operation lever 32b is tilted backward (toward the near side), the gripper 80 (gripping portion 81) is moved horizontally backward in a straight line within the boom hoisting surface.

[0057] This control is performed by the position calculation section 101, operation control section 102, and horizontal / vertical movement control section 107 of the controller 100. First, the position calculation section 101 calculates the position of the tip of the boom 13 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, and then calculates the position of the gripper 80 (gripping section 81) relative to the tip of the boom 13 (relative to the vehicle body 2) based on this detection information as well as detection information from the gripping section inclination angle detector 124 and the arm swing angle detector, and calculates the position of the gripper 80 (gripping section 81) relative to the vehicle body 2. Then, the operation control section 102 controls the operation of the control valve 112, which in turn controls the operation of the hydraulic actuators (in particular, the swing motor 14, the telescopic cylinder 15, the hoisting cylinder 16, the arm cylinder 55, the vertical swing cylinder 62, and the horizontal swing cylinder 71), and moves the gripper 80 (gripping portion 81) horizontally and linearly in the forward and backward directions within the boom hoisting surface in response to the operation of the boom telescopic / bending / extending operation lever 32b, which is the horizontal operation lever.

[0058] In this way, the gripper 80 (gripping portion 81) is moved in a horizontal linear direction, and this control is performed by calculating the position of the gripper 80 (gripping portion 81), which changes every moment due to the operation control of the hydraulic actuator, using the position calculation portion 101, and operating the hydraulic actuator according to the calculation result. In other words, feedback control is performed in which the position calculation and the actuator operation control are repeated in small time units (control cycle time units).

[0059] This control will be described with reference to Fig. 12. Fig. 12 explains the operation when controlling the horizontal movement of the gripper 80 (gripping section 81) in the movement speed command mode, and shows the operation when the boom extension / contraction bending / extension operation lever 32b, which functions as a horizontal operation lever, is tilted forward (in the direction toward the rear) to control the linear movement of the gripper 80 (gripping section 81) horizontally forward (to the right in Fig. 12). When the boom extension / contraction bending / extension operation lever 32b, which functions as a horizontal operation lever, is tilted forward, a command signal for moving the gripper 80 (gripping section 81) horizontally forward as indicated by arrow H is output to the controller 100. When the controller 100 receives this command signal, the position detector 101 determines the position of the tip of the boom 13 and the position of the gripper 80 (gripping section 81).

[0060] The command signal output by tilting the boom telescopic bending / extension operation lever 32b forward indicates the direction of movement of the tip of the boom 13 and the gripper 80 (holding portion 81) horizontally forward, and also indicates the speed of movement corresponding to the amount of operation. In the horizontal / vertical movement control section 107 of the controller 100 that receives this command signal, a vector for moving the tip of the boom 13 horizontally forward at the commanded speed of movement is resolved into the operation of raising and lowering the boom 13, and a target direction and speed of extension of the boom 13 are obtained. However, at this time, no control is performed to swing the arm 51 up and down relative to the tip of the boom 13. Therefore, as the boom 13 rises and falls, the angle of the arm 51 with respect to the horizontal changes, and the position of the gripper 80 (gripping portion 81) also moves up and down, so that the target telescopic direction and telescopic movement speed of the boom 13 are determined so that the vertical movement of the gripper 80 (gripping portion 81) is offset and the gripper 80 (gripping portion 81) moves horizontally forward as shown by arrow H in Fig. 12. Then, the boom 13 is raised and lowered in the target telescopic direction and telescopic movement speed thus determined, and the boom 13 is telescopically moved in the target telescopic direction and telescopic movement speed. As a result, the gripper 80 (gripping portion 81) moves horizontally forward as shown by arrow H at the commanded movement speed. However, in order to keep the direction of the gripper 80 (gripping portion 81) constant regardless of the raising and lowering of the boom 13 and to keep the held utility pole P vertical, the vertical swing of the gripper 80 (gripping portion 81) is controlled to swing up and down in the opposite direction to the raising and lowering of the boom 13 (the direction shown by arrow C). As a result, in response to the operation of tilting the boom extension / contraction bending / extension operation lever 32b forward, the gripper 80 (gripping portion 81) moves horizontally forward as shown by arrow H in Fig. 12. As a result, the gripper 80 (gripping portion 81) moves horizontally at a constant speed corresponding to the operation of the boom extension / contraction bending / extension operation lever 32b, allowing for smooth horizontal movement.

[0061] In this way, the control of moving the gripper 80 (gripping unit 81) horizontally forward requires repeated calculation of the gripper 80 (gripping unit 81) position and actuator drive control in small time units (control cycle time units), and there is a detection error for two axes (elevation angle, amount of expansion and contraction) by the position sensor. Therefore, an error (variation) occurs in the actual horizontal movement trajectory of the gripper 80 (gripping unit 81) compared to the target movement trajectory.

[0062] The movement speed command mode SPM prioritizes movement to a target position when gripping and transporting an electric pole or the like with the gripper 80 (grip unit 81), and allows a certain degree of error (fluctuation) that occurs between the actual horizontal movement trajectory of the gripper 80 (grip unit 81) and the target movement trajectory. This ensures the work efficiency when gripping and transporting an electric pole or the like with the gripper 80 (grip unit 81).

[0063] In the above, the control for moving the tip of the boom 13 and the gripper 80 (gripping portion 81) horizontally forward in the movement speed command mode SPM has been described with reference to Fig. 12, but the control for moving them horizontally backward is similar. Note that the control for moving them horizontally outside the plane in the hoisting direction of the boom 13 can be performed by moving the tip of the boom 13 and the gripper 80 (gripping portion 81) laterally by the rotation of the boom 13 to adjust their positions, and then controlling the tip of the boom 13 and the gripper 80 (gripping portion 81) in the horizontal direction (the horizontal direction within the plane in the hoisting direction of the boom 13). Note that the control for vertically moving the gripper 80 (gripping portion 81) in response to the operation of the boom rotation / hoisting operation lever 32a, which has the function of a vertical operation lever, is similar, so a description of the operation will be omitted.

[0064] (APM movement precision improvement mode) Next, the control of moving the gripper 80 (gripping section 81) horizontally and vertically in the movement accuracy improvement mode APM will be described. Even when the indicator of the mode selection switch 33 is operated to the position of the movement accuracy improvement mode APM and the movement accuracy improvement mode APM is selected, the gripper 80 (gripping section 81) is moved horizontally in response to the operation of the boom telescopic / flexing / extending operation lever 32b having the function of a horizontal operation lever, and the gripper 80 (gripping section 81) is moved vertically in response to the operation of the boom swing / hoisting operation lever 32a having the function of a vertical operation lever. However, the content of the control is different from that in the movement speed command mode SPM. Furthermore, there is a difference between the control of moving the gripper 80 (gripping section 81) horizontally in response to the operation of the boom telescopic / flexing / extending operation lever 32b and the control of moving the gripper 80 (gripping section 81) vertically in response to the operation of the boom swing / hoisting operation lever 32a having the function of a vertical operation lever. First, the control of vertically moving the gripper 80 (the gripping portion 81) in response to the operation of the boom rotation / hoisting operation lever 32a, which has a function as a vertical operation lever, will be described.

[0065] As mentioned above, when installing a utility pole into a pole hole, the difference between the diameter of the pole hole (approximately 450 mm) and the diameter of the utility pole to be inserted into this hole (approximately 390 mm) is small, so vertical movement with high position control precision is required. The movement accuracy improvement mode APM provides control to meet such requirements.

[0066] In the movement accuracy improved mode APM, the control mode in which the gripper 80 (gripping part 81) is moved vertically in response to operation of the boom swing / hoisting operation lever 32a, which is the vertical operation lever, is a control performed by the operation control part 102 together with the horizontal / vertical movement control part 107. In this control as well, first, the position calculation part 101 calculates the position of the tip of the boom 13 relative to the vehicle body 2 based on detection information from the boom hoisting angle detector 120 and the boom extension amount detector 121, and then calculates the position of the gripper 80 (gripping part 81) relative to the tip of the boom 13 based on detection information from the gripper inclination angle detector 124 and the arm swing angle detector in addition to this detection information, thereby calculating the position of the gripper 80 (gripping part 81) relative to the vehicle body 2. The operation control unit 102 then controls the operation of the control valve 112, which in turn controls the operation of the hydraulic actuators (particularly the telescopic cylinder 15, the hoisting cylinder 16, and the vertical swing cylinder 62), and moves the gripper 80 (gripping portion 81) vertically in response to the operation of the boom rotation / hoisting operation lever 32a, which is the vertical operation lever.

[0067] In this way, the gripper 80 (holding portion 81) is moved in a vertical linear direction. The control is also performed by calculating the position of the gripper 80 (holding part 81), which changes every moment due to the operation control of the hydraulic actuator, using the position calculation part 101, and operating the hydraulic actuator according to the calculation result. That is, feedback control is performed by repeating the position calculation and the actuator operation control in small time units (control cycle time units).

[0068] This control will be described with reference to Figure 13. Figure 13 explains the operation when control is performed in the movement accuracy improvement mode, and shows the operation when the boom rotation / hoisting operation lever 32a, which functions as a vertical operation lever, is tilted forward (toward the rear) to control the gripper 80 (gripping portion 81) to move vertically downward in a straight line. When the boom rotation / hoisting operation lever 32a is tilted forward, a command signal is output to the controller 100 to move the gripper 80 (gripping portion 81) vertically downward as shown by arrow V. When the controller 100 receives this command signal, the position detector 101 determines the position of the tip of the boom 13 and the position of the gripper 80 (gripping portion 81).

[0069] The command signal output by the operation of tilting the boom rotation / hoisting operation lever 32a forward indicates the direction of movement of the tip of the boom 13 and the gripper 80 (gripping portion 81) vertically downward, and also indicates the speed of movement corresponding to the amount of operation. In the horizontal / vertical movement control portion 107 of the controller 100 that receives this command signal, control is performed to perform an operation to raise / lower (lower) the boom 13 at a speed corresponding to the command, and in parallel with this, an operation to retract the boom 13 so as to move the gripper 80 (gripping portion 81) vertically downward. At this time, control is not performed to swing the arm 51 up and down relative to the tip of the boom 13. Therefore, the angle of the arm 51 with respect to the horizontal changes due to the raising and lowering of the boom 13, and the position of the gripper 80 (gripping portion 81) also moves in the front-rear direction. Therefore, a target telescopic direction and telescopic movement speed of the boom 13 are determined so that the front-rear movement of the gripper 80 (gripping portion 81) is offset and the gripper 80 (gripping portion 81) moves vertically downward as shown by the arrow V in FIG. 13. Then, the boom 13 is telescopically moved in the target telescopic direction and telescopic movement speed thus determined. As a result, the tip of the boom 13 moves vertically downward as shown by the arrow V. However, in order to keep the direction of the gripper 80 (gripping portion 81) constant regardless of the raising and lowering of the boom 13 and to keep the held utility pole P vertical, the vertical swing of the gripper 80 (gripping portion 81) is controlled to swing up and down in the opposite direction to the raising and lowering of the boom 13 (the direction shown by the arrow C). As a result, in response to the operation of tilting the boom rotation / hoisting operation lever 32a forward, the gripper 80 (the gripping portion 81) moves vertically downward as indicated by the arrow V in FIG.

[0070] As described above, in the control of vertically moving the gripper 80 (gripping portion 81) in response to the operation of the boom rotation / hoisting operation lever 32a, the boom 13 is raised and lowered (lowered) at an operating speed corresponding to a command in response to the operation of tilting the boom rotation / hoisting operation lever 32a forward, and accordingly, the boom 13 is contracted so as to move the gripper 80 (gripping portion 81) vertically downward. At this time, if the amount of operation of the boom rotation / hoisting operation lever 32a becomes too large, the corresponding operation of contracting the boom 13 may not be able to keep up. For this reason, the speed at which the boom 13 is raised and lowered is limited to a speed at which the extension and retraction movement of the boom 13 can keep up.

[0071] In this way, the control of moving the gripper 80 (gripping portion 81) vertically downward requires repeated calculation of the position of the gripper 80 (gripping portion 81) and actuator operation control in fine time units (control cycle time units); however, as explained above, in the movement accuracy improvement mode APM, the boom 13 is raised and lowered at a predetermined speed according to the operation, and only telescopic movement control of the boom 13 is required. Therefore, the calculation error is small, and the drive error is due only to the telescopic cylinder, so that it is possible to accurately control the vertical movement of the gripper 80 (gripping portion 81).

[0072] In this way, in the movement accuracy improvement mode APM, the movement control accuracy is prioritized over the movement of the gripper 80 (holding unit 81) to the target position, and the vertical movement trajectory of the gripper 80 (holding unit 81) is made closer to the target movement trajectory. This makes it easier to accurately align the utility pole held by the gripper 80 (holding unit 81) when inserting it into the pole hole, as will be described later, and makes it possible to perform pole erection work efficiently.

[0073] Although the control for moving the tip of the boom 13 and the gripper 80 (gripping portion 81) vertically downward in the movement accuracy improvement mode APM has been described above with reference to FIG. 13, the control for moving them vertically upward is similar.

[0074] Next, the control for horizontally moving the gripper 80 (gripping section 81) in response to the operation of the boom extension / contraction bending / extension operation lever 32b will be described. In this control as well, first, the position calculation section 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 hoist angle detector 120 and the boom extension amount detector 121, and then calculates the position of the gripper 80 (gripping section 81) relative to the tip of the boom 13 based on the detection information from the gripper inclination angle detector 124 and the arm swing angle detector in addition to these detection information, thereby calculating the position of the gripper 80 (gripping section 81) relative to the vehicle body 2. Then, the operation control section 102 controls the operation of the control valve 112, controls the operation of the hydraulic actuators (particularly the telescopic cylinder 15, the hoist cylinder 16, and the vertical swing cylinder 62), and moves the gripper 80 (gripping section 81) horizontally within the boom hoisting surface in response to the operation of the boom extension / contraction bending / extension operation lever 32b, which is the horizontal operation lever.

[0075] In this way, the gripper 80 (gripping portion 81) is moved in a horizontal linear direction, and this control is also performed by calculating the position of the gripper 80 (gripping portion 81), which changes every moment due to the operation control of the hydraulic actuator, using the position calculation portion 101, and operating the hydraulic actuator according to the calculation result. In other words, feedback control is performed in which position calculation and actuator operation control are repeated in small time units (control cycle time units).

[0076] In the movement accuracy improvement mode, the boom extension / contraction bending / extension operation lever 32b, which functions as a horizontal operation lever, is tilted forward (toward the rear) to control the linear movement of the gripper 80 (gripping unit 81) horizontally forward, as described below. When the boom extension / contraction bending / extension operation lever 32b is tilted forward, a command signal to move the gripper 80 (gripping unit 81) horizontally forward is output to the controller 100. When the controller 100 receives this command signal, the position detector 101 determines the position of the tip of the boom 13 and the position of the gripper 80 (gripping unit 81).

[0077] The command signal output by the operation of tilting the boom telescopic bending / extension operation lever 32b forward indicates the direction of movement of the tip of the boom 13 and the gripper 80 (gripping portion 81) horizontally forward, and also indicates the speed of movement corresponding to the amount of operation. In the horizontal / vertical movement control portion 107 of the controller 100 that receives this command signal, an operation is performed to extend the boom 13 at a speed corresponding to the command, and in parallel with this, a control is performed to lower the boom 13 so as to move the gripper 80 (gripping portion 81) horizontally forward. At this time, it is not controlled to swing the arm 51 up and down relative to the tip of the boom 13. Therefore, as the boom 13 rises and falls, the angle of the arm 51 with respect to the horizontal changes, and the position of the gripper 80 (gripping portion 81) also moves up and down; therefore, a target lifting direction and lifting speed of the boom 13 are determined so that the vertical movement of the gripper 80 (gripping portion 81) is offset and the gripper 80 (gripping portion 81) moves horizontally forward. The boom 13 is then raised and lowered in the target lifting direction and lifting speed thus determined. As a result, the tip of the boom 13 moves horizontally forward. However, in order to keep the direction of the gripper 80 (gripping portion 81) constant regardless of the rise and fall of the boom 13, and to keep the held utility pole P vertical, the gripper 80 (gripping portion 81) The vertical swing of the boom 13 is controlled to swing up and down in the direction opposite to the direction of raising and lowering of the boom 13. As a result, the gripper 80 (gripping portion 81) moves horizontally forward within the raising and lowering surface of the boom 13 in response to the operation of tilting the boom extension / contraction bending / extension operation lever 32b forward.

[0078] As described above, in the control of horizontally moving the gripper 80 (gripping section 81) in response to the operation of the boom telescopic bending / extension operating lever 32b, the boom 13 is extended at a speed corresponding to a command in response to the operation of tilting the boom telescopic bending / extension operating lever 32b forward, and accordingly, the boom 13 is lowered (lowered) so as to move the gripper 80 (gripping section 81) horizontally forward. At this time, if the amount of operation of the boom telescopic bending / extension operating lever 32b becomes too large and the extension speed of the boom 13 becomes fast, the corresponding operation of raising and lowering the boom 13 may not be able to keep up. For this reason, the speed at which the boom 13 is telescopically moved is limited to a speed at which the boom 13 can keep up with the lifting and lowering movement.

[0079] Although the control for moving the tip of the boom 13 and the gripper 80 (the gripping portion 81) horizontally forward in the movement accuracy improvement mode APM has been described above, the control for moving them horizontally backward is also similar.

[0080] (Automatic switching mode AUTM) The automatic switching mode AUTM is also a control mode for moving the gripper 80 (gripping unit 81) vertically or horizontally in response to the operation of the boom slewing / hoisting operation lever 32a and the boom telescopic / flexing operation lever 32b, and is performed by the operation control unit 102 and the horizontal / vertical movement control unit 107. When the automatic switching mode AUTM is set, control is performed to automatically switch between the movement speed command mode SPM and the movement accuracy improvement mode APM based on predetermined conditions. The predetermined conditions include use conditions that require the movement speed command mode SPM and use conditions that require the movement accuracy improvement mode APM. For example, the gripping-type pole hole digging vehicle 1 may be used to insert a utility pole gripped by the gripper 80 (gripping unit 81) into a pole hole excavated by the auger device 20 to perform pole erection work. In this case, automatic switching control is performed based on the use conditions as follows. During pole erection work, the difference between the size of the pole hole (diameter of about 450 mm) and the size of the utility pole (diameter of 390 mm) is small, and the position of the utility pole must be precisely controlled to insert it into the pole hole. For this reason, when the automatic switching mode AUTM is set, the movement accuracy improvement mode APM is automatically set when the utility pole held by the gripper 80 (holding unit 81) is held in a vertically extended state, and the movement speed command mode SPM is automatically set otherwise. This allows the utility pole held by the gripper 80 (holding unit 81) in a vertically extended state to be precisely positioned, and the work of inserting the utility pole into the pole hole can be performed accurately and easily. A specific example of pole erection work using the gripping-type hole digging pole erection vehicle 1 will be described later.

[0081] When automatic vertical switch 34 of operating device 31 is turned on, automatic vertical control unit 105 determines whether the tilt angle of grip unit 81 detected by grip unit tilt angle detector 124 is within a predetermined angle (for example, within 5 degrees) with respect to the horizontal. Here, automatic vertical control unit 105 stores an automatic vertical program, and if it determines that the tilt angle of grip unit 81 is within the predetermined angle with respect to the horizontal when an operation signal is input from automatic vertical switch 34, it outputs a command signal to operation control unit 102 based on the detection information from grip unit tilt angle detector 124 in accordance with the automatic vertical program. When the operation control unit 102 receives a command signal from the automatic vertical control unit 105, it feeds back the inclination angle of the gripping unit 81 from the gripping unit inclination angle detector 124, and based on the fed back information, it corrects the forward / backward inclination of the gripping unit 81 by extending and retracting the vertical swivel cylinder 62 until the forward / backward inclination angle of the gripping unit 81 reaches the target angle (0 degrees), and also corrects the left / right inclination of the gripping unit 81 by rotating the gripper motor 79 until the left / right inclination angle of the gripping unit 81 reaches the target angle (0 degrees).

[0082] Regarding the tilt of the gripper 81 in the front-rear direction, the gripper 81 can be tilted downward (see the Y1 direction in FIG. 14) by extending the vertical swing cylinder 62, and can be tilted upward (see the Y2 direction in FIG. 14) by contracting the vertical swing cylinder 62. Regarding the tilt of the gripper 81 in the left-right direction, the gripper 81 can be tilted leftward (see the Z1 direction in FIG. 14) around the rotation axis X by rotating the gripper motor 79 forward, and can be tilted rightward (see the Z2 direction in FIG. 14) around the rotation axis X by rotating the gripper motor 79 backward. In this way, the operation control unit 102 executes feedback control based on the deviation between the tilt angle of the gripper 81 and the target angle (0 degrees) based on a command from the automatic vertical control unit 105, and sets the gripper 81 in a horizontal position (the utility pole gripped by the gripper 81 in a vertical position). The automatic vertical control is used not only when gripping unit 81 is placed in a horizontal position while gripping a utility pole (i.e., when gripping unit 81 is placed in a vertical position for the utility pole it grips), but also when gripping unit 81 is placed in a horizontal position while not gripping a utility pole (when gripping unit 81 is not gripping anything).As a variation of this, automatic vertical control unit 105 may be configured to perform automatic vertical control only when grip determination unit 104 has determined that gripping unit 81 is gripping a utility pole (target object).

[0083] Next, a pole erection operation using the grip-type hole digging pole erection vehicle 1 of this embodiment will be described with reference to Fig. 15 to Fig. 17. Below, a pole erection operation of erecting a utility pole into a pole erection hole using the grip-type hole digging pole erection vehicle 1 of this embodiment will be described in order.

[0084] The pole erection work described below is a work in which the utility pole P placed horizontally on the support base S is gripped by the gripper 80 (grip 81) at the tip of the gripping device 50, transported, and erected into the pole erection hole K formed by excavation as described above. First, the mode selection switch 33 is operated to set the normal operation mode NM. Then, the operation device 31 is operated to rotate, raise and lower, and extend the boom 13, and to perform vertical and horizontal swinging and rotational movements of the gripper 81, so that the gripper 80 (grip 81) moves to the utility pole P placed horizontally on the support base S, and the gripper 80 (grip 81) grips the utility pole P. As for the arm 51, if it swings up and down so as to approach (close) the boom 13, the gripped utility pole P will easily come into contact with the arm 51, etc., so the arm 51 is swung up and down so as to be at the maximum angle away (open). In addition, the operation of moving the gripper 80 (holding portion 81) to the utility pole P placed horizontally on the support base S in this manner may be performed by vertical movement in the movement speed command mode SPM or the movement accuracy improvement mode APM.

[0085] Next, as shown by the dashed dotted line V1 in Fig. 15, the gripper 80 (gripping portion 81) is moved vertically upward, and the gripped utility pole P is transported vertically upward while being gripped sideways. This transport may be performed by operating the operation device 31 in the normal operation mode NM to rotate, hoist, or extend / retract the boom 13, or may be performed by switching to the movement speed command mode SPM or the movement accuracy improvement mode APM and operating the boom rotation / hoist operation lever 32a to move vertically.

[0086] Next, the mode is switched to the travel speed command mode SPM, and the boom telescopic bending / extending operation lever 32b, which functions as a horizontal operation lever, is tilted to move the gripper 80 (holding section 81) horizontally in the tilting operation direction. As a result, as shown by the dashed line H1 in Fig. 15 and Fig. 16, the gripper 80 (holding section 81) moves horizontally, and the gripped utility pole P is transported horizontally while being held sideways. Such horizontal transport of the utility pole P is performed toward the upper position of the excavated post hole K, and the utility pole P gripped by the gripper 80 (holding section 81) is transported to the upper position of the post hole K. Note that, since the horizontal movement is performed within the boom hoisting surface as described above, the boom is rotated in advance so that the boom hoisting surface overlaps with the post hole.

[0087] In this way, the utility pole P held horizontally by the gripper 80 (holding portion 81) is placed in the pole hole K. 16, the automatic vertical switch 34 is then turned on. This causes the automatic vertical control section 105 of the controller 100 to control the operation of the vertical oscillating cylinder 62 and the gripper motor 79, causing the gripper 80 (gripping section 81) to oscillate and rotate, and bringing the gripping section 81 into a horizontal position. As a result, the utility pole P gripped horizontally by the gripper 80 (gripping section 81) is rotated as shown by arrows R1 and R2 in Fig. 16, and comes to a state of being extended vertically as shown in Fig. 17.

[0088] Next, the mode selection switch 33 is operated to switch from the travel speed command mode SPM to the travel accuracy improvement mode APM. Then, the boom rotation / hoisting operation lever 32a, which functions as a vertical operation lever, is tilted forward (toward the rear side), and the gripper 80 (gripping part 81) moves vertically downward as shown by the dashed line V2 in FIG. 17, and the gripped utility pole P is conveyed vertically downward while being extended vertically. This operation inserts the lower part of the utility pole P into the pole hole K, but since the difference between the size of the pole hole (diameter of about 450 mm) and the size of the utility pole (diameter of 390 mm) is small, it is required to precisely control the position of the utility pole and insert it into the pole hole. Here, the mode is switched to the travel accuracy improvement mode APM, so precise positioning can be performed under this travel accuracy improvement mode APM.

[0089] The pole erection work described above can also be performed in a state where the automatic switching mode AUTM is set by operating the mode selection switch 33. In this case, first, in the normal operation mode NM, the operating device 31 is operated to move the gripper 80 (holding unit 81) to the utility pole P placed horizontally on the support base S, and the gripper 80 (holding unit 81) holds the utility pole P and lifts it up as shown in FIG. 15. After that, the mode selection switch 33 is operated to switch from the normal operation mode NM to the automatic switching mode AUTM. In this automatic switching mode AUTM, when the utility pole held by the gripper 80 (holding unit 81) is in a state where it extends vertically as shown in FIG. 17 (preferably within a predetermined angle including the position where it extends vertically, for example, within a range of several degrees), the movement accuracy improvement mode APM is set, and when the extension angle of the utility pole P is in a state other than that, the movement speed command mode SPM is set.

[0090] For this reason, as shown in Fig. 15, when the utility pole P is gripped sideways by the gripper 80 (grip portion 81), the travel speed command mode SPM is automatically set. Then, the boom telescopic bending / extension operation lever 32b, which functions as a horizontal operation lever, is tilted to horizontally move the gripper 80 (grip portion 81) in the tilt operation direction. This causes the gripper 80 (grip portion 81) to move horizontally, as shown by the dashed dotted line H1 in Figs. 15 and 16, and the gripped utility pole P is transported horizontally while being gripped sideways, and the utility pole P gripped by the gripper 80 (grip portion 81) is transported to a position above the pole hole K.

[0091] Next, when the automatic vertical switch 34 is turned on, the automatic vertical control unit 105 of the controller 100 controls the operation of the gripper 80 (gripping unit 81), and the utility pole P gripped horizontally by the gripper 80 (gripping unit 81) is extended vertically as shown in FIG. 17. As a result, the movement speed command mode SPM is automatically switched to the movement accuracy improvement mode APM. In this state, the boom rotation / hoisting operation lever 32a, which functions as a vertical operation lever, is tilted forward (toward the back side), and the gripper 80 (gripping unit 81) is moved vertically downward as shown by the dashed line V2 in FIG. 17, and the gripped utility pole P is transported vertically downward while being gripped and extended vertically. As described above, under the movement accuracy improvement mode APM, the utility pole P is inserted into the pole hole K, and the pole erection work of installing the utility pole P in the pole hole is performed.

[0092] The main effects achieved in this embodiment can be summarized as follows:

[0093] According to this embodiment, when the automatic vertical switch 34 is operated, the vertical swing series is adjusted in accordance with the tilt angle of the grip portion 81 relative to the horizontal plane detected by the grip portion tilt angle detector 124. By operating the gripper 62 and the gripper motor 79 to change the posture of the gripping unit 81, the utility pole held by the gripping unit 81 can be brought into a vertical posture along the vertical direction. Therefore, even on sloping ground such as mountainous areas, the utility pole held by the gripping unit 81 can be automatically brought into a vertical posture without the need for skilled operating techniques, making it possible to dramatically improve the work efficiency of pole erection work.

[0094] Furthermore, in this embodiment, control is performed to bring the utility pole held by the gripping part 81 into a vertical position only when the inclination angle of the gripping part 81 relative to the horizontal plane detected by the gripping part inclination angle detector 124 is within a specified angle. This makes it possible to limit the range of motion for changing the gripping part 81 into a vertical position, thereby preventing the utility pole from interfering with surrounding structures or the ground or coming into contact with the worker, and ensuring the safety of the work.

[0095] In addition, in this embodiment, when a pole is erected by gripping a utility pole with a gripping device and inserting it into a pole hole, the moving speed command mode SPM and the moving accuracy improvement mode APM can be selected and set, so that, for example, when a utility pole is gripped and transported to the top of the pole hole, the moving speed command mode SPM can be set to perform a quick and efficient transport operation, and when the utility pole is inserted into the pole hole, the moving accuracy improvement mode APM can be set to perform accurate position control and perform pole erection work accurately and easily. In particular, as described above, the automatic switching mode AUTM can also be set, which allows appropriate automatic switching between the moving speed command mode SPM and the moving accuracy improvement mode APM, allowing more efficient pole erection work, etc.

[0096] 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.

[0097] 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).

[0098] In addition, in the above embodiment, a PTO-driven 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) pole hole digger vehicle, or a hybrid type pole hole digger vehicle that has both and can selectively switch between power sources. [Explanation of symbols]

[0099] 1. Grab-type hole digging vehicle 2. Vehicle body 12 Swivel table 13 Boom 20 Auger device 22 Auger motor 25 Earth Ogre 31 Operating device 33 Mode Select Switch 34 Automatic Vertical Switch 50 Grasping device 51 Arm 55 arm cylinder 60 first joint member 62 vertical swivel cylinder 70 second joint member 71 Swing cylinder 79 Gripper motor 80 Gripper 81 Gripping part 82 Grip jaw 99 Gripper cylinder 100 Controller 101 Position calculation unit 102 Operation control unit 103 Auger inclination determination unit 104 Grip determination section 105 Automatic vertical control section 106 Load determination unit 107 Horizontal / vertical movement control unit 124 Grip inclination angle detector 125 Grip load detector 126 Gripper cylinder pressure detector P Electric pole K Post hole

Claims

1. A grip-type work vehicle comprising: a vehicle body; a boom that is provided on the vehicle body so as to be capable of rotating, raising and lowering, and extending and contracting; a gripping section that is capable of gripping an object to be gripped; and a support mechanism that is provided between a tip of the boom and the gripping section and that changes the attitude of the gripping section relative to the tip of the boom, A plurality of actuators for actuating the boom and the support mechanism; a boom hoisting angle detector for detecting a boom hoisting angle and a boom extension amount detector for detecting a boom extension length; an operating device that outputs a movement command for moving the gripping unit horizontally or vertically in response to an operation; a mode setting device capable of selectively setting a movement speed command mode and a movement accuracy improvement mode as modes for moving the gripping unit horizontally or vertically based on the movement command from the operating device; a control device that, when the movement speed command mode is set by the mode setting device, moves the gripping unit horizontally or vertically under the movement speed command mode based on the movement command from the operation device, and, when the movement accuracy improvement mode is set by the mode setting device, controls the gripping unit to move horizontally or vertically under the movement accuracy improvement mode based on the movement command from the operation device; In the movement speed command mode, the control of moving the gripping unit horizontally or vertically by the control device is determining a target horizontal movement direction and a target horizontal movement speed, or a target vertical movement direction and a target vertical movement speed, of the gripping part, which are obtained in response to the movement command from the operating device, into a raising and lowering movement and a retracting movement of the boom, to obtain a target raising and lowering direction and a target raising and lowering speed, and a target retracting direction and a target retracting speed, determining a position of the gripping part from detection values ​​obtained by the boom hoist angle detector and the boom extension amount detector while performing a combination of control for raising and lowering the boom in the target hoisting direction and at the target hoisting speed and control for extending and retracting the boom in the target telescopic direction and at the target telescopic speed; the gripping unit, the position of which is thus obtained, is controlled while correcting the target hoisting speed and the target extension / contraction speed of the boom so that the gripping unit moves in the target horizontal movement direction or the target vertical movement direction at the target horizontal movement speed or the target vertical movement speed, In the movement accuracy improvement mode, the control of vertically moving the gripping unit by the control device includes: Based on a vertical movement command from the operating device, control is performed to raise and lower the boom in response to the operation of the operating device, and control is also performed to extend and retract the boom so that the gripping part moves vertically in response to the raising and lowering of the boom, a boom hoisting angle detector and a boom extension amount detector, and a control unit configured to determine the position of the gripper from values ​​detected by the boom hoisting angle detector and the boom extension amount detector, and to perform control to correct a target extension / retraction speed of the boom so that the gripper whose position has been determined in this manner moves vertically.

2. The control device is configured to also perform control to horizontally move the gripping unit in the movement accuracy improvement mode, The control of the horizontal movement is Based on a horizontal movement command from the operation device, control is performed to extend and retract the boom, and in response to the extension and retraction of the boom, control is also performed to raise and lower the boom so that the gripping part moves horizontally, 2. A grip-type work vehicle as described in claim 1, characterized in that the position of the gripper is determined from the detection values ​​of the boom hoisting angle detector and the boom extension amount detector, and a target hoisting speed of the boom is corrected so that the gripper whose position is determined in this manner moves horizontally.

3. The object to be grasped is a column-shaped object such as a utility pole, a columnar object gripping angle detector that detects an angle of an extension direction of the columnar object relative to the gripping portion when the columnar object is gripped by the gripping portion; The gripping-type work vehicle according to claim 1 or 2, characterized in that the control device is capable of automatically switching between control in the movement speed command mode and control in the movement accuracy improvement mode using the angle detected by the column gripping angle detector as the specified condition.

4. The gripping portion has a pair of openable and closable gripping claws for gripping the columnar object, the support mechanism has a rotation mechanism that rotates the gripping jaws about a rotation axis perpendicular to the opening and closing direction of the gripping jaws, The gripping claws are rotated by the rotation mechanism to adjust the angle at which the columnar object is held by the gripping claws, The columnar object gripping angle detection can detect an angle at which the columnar object gripped by the gripping claws is held, The gripping-type work vehicle according to claim 3, characterized in that the control device is capable of automatically switching between control in the movement speed command mode and control in the movement accuracy improvement mode, using the angle detected by the column gripping angle detection as the specified condition.

5. the control device switches to control in the movement accuracy improvement mode when it is detected by the columnar object gripping angle detection that the columnar object gripped by the gripping unit is extended and held at an angle within a predetermined angle range including a vertical direction, A gripping-type work vehicle as described in claim 3, characterized in that when the detection of the column gripping angle detects that the column gripped by the gripping portion is extended and held at an angle outside the specified angle range, the control is switched to the movement speed command mode.

Images