Crane truck

Abstract

To provide a crane truck which enables hook storage work to be efficiently carried out.SOLUTION: The crane truck comprises: a winch device that includes a boom head provided in a tip part of a boom and a wire having a hook fitted to the tip end, and raises or lowers the hook by performing a winding operation and a delivering operation of the wire; a controller 50 that causes the winch device to perform the winding operation or the delivering operation in accordance with an operation of an operation device 19; a tension detector 48 that detects the tension of the wire; and a boom position determination unit 52 that determines whether or not the boom exists at a prescribed position. The controller 50 causes the winch device to stop the winding operation irrespective of the operation of the operation device 19 when the tension detector 48 detects that the tension of the wire becomes equal to or higher than a prescribed value when making the winch device perform the winding operation in a state where the boom position determination unit 52 determines that the boom is at the prescribed position.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a crane truck having a crane device mounted on a running body, which can hoist and move an object to be transported. [Background technology]

[0002] Conventionally, some crane vehicles, such as the pole hole digger vehicle described in Patent Document 1, are equipped with an auger device that digs holes for erecting pole-like objects such as utility poles in addition to the crane device. This pole hole digger vehicle is equipped with an overwinding prevention device to prevent the hook from being pressed against the boom head excessively and damaging each other or the wire from being damaged by excessive tension when the winch of the crane device winds up too much wire, or when the boom is extended or lowered while the hook of the crane device is close to the boom head provided at the end of the boom. This overwinding prevention device is designed to stop the winch winding operation when it detects that the hook and the boom head have come close to a predetermined distance while the winch is winding up the wire. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Utility Model Registration No. 3089000 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if a crane vehicle travels with the hook hanging from the boom head, the hook may swing due to shaking while traveling or acceleration / deceleration when starting / stopping, which may damage the vehicle or surrounding structures. Therefore, in order to keep the hook stable even while the crane vehicle is traveling, it is possible to prevent the hook from swinging by, for example, winding the wire with a winch until the hook abuts the boom head, thereby pressing the hook against the boom head. Hereinafter, the work to keep the hook stable is referred to as the "hook storage work."

[0005] During the operation of storing the hook, if, for example, a worker winds up too much wire with the winch, the hook may be pressed against the boom head with more force than necessary, which may damage the hook or the boom head, or the wire. Also, in a crane vehicle equipped with the above-mentioned over-winding prevention device, if the over-winding prevention device is activated during the process of winding up the winch to bring the hook into contact with the boom head, and the winch's winding operation stops as a result, it is necessary to release the over-winding prevention device and then perform an operation to wind up the winch again, which creates a problem of making the operation of storing the hook cumbersome.

[0006] The present invention has been made in consideration of the above problems, and has an object to provide a crane truck that can perform hook storage work appropriately and efficiently. [Means for solving the problem]

[0007] In order to solve the above problems, the crane vehicle of the present invention includes a travelling body (for example, vehicle body 2 in the embodiment), a boom that is arranged so as to be able to be raised and lowered with respect to the travelling body, a sheave, a boom head that is arranged at the tip of the boom, a hook that is attached to the tip, and a wire that is wound around the sheave, and a winch device that raises and lowers the hook suspended from the sheave by winding and unwinding the wire. the winch control device comprises an operating device for operating the winding and pay-out operations of the winch device, a winch control device (e.g., controller 50 in the embodiments) for causing the winch device to perform a winding or pay-out operation in response to operation of the operating device, a tension detection device (e.g., tension detector 48 in the embodiments) for detecting the tension of the wire, and a boom position determination device (e.g., boom position determination unit 52 in the embodiments) for determining whether or not the boom is at a predetermined position, and the winch control device is characterized in that when the winch device is being caused to perform a winding operation while the boom position determination device has determined that the boom is at the predetermined position, if the tension detection device detects that the tension of the wire has reached a predetermined value or greater, the winch control device stops the winding operation of the winch device regardless of operation by the operating device.

[0008] Furthermore, in the crane vehicle having the above configuration, it is preferable that the winch control device is further provided with a gap detection device (for example, over-winding detector 35 in the embodiment) which detects when the gap between the boom head and the hook has reached a predetermined gap, and when the winch control device is causing the winch device to perform a winding operation in a state in which the boom position determination device has determined that the boom is not at the predetermined position, if the gap detection device detects that the gap between the boom head and the hook has reached the predetermined gap, the winch control device stops the winding operation of the winch device regardless of operation by the operating device, and when the winch device is causing the winch device to perform a winding operation in a state in which the boom position determination device has determined that the boom is at the predetermined position, if the gap detection device detects that the gap between the boom head and the hook has reached the predetermined gap, the winch control device maintains the winding operation of the winch device, and thereafter stops the winding operation of the winch device regardless of operation by the operating device when the tension detection device detects that the tension of the wire has reached a predetermined value or more.

[0009] Furthermore, in a crane vehicle having any of the above configurations, the boom has a structure that is extendable and contractable in the longitudinal direction, and is equipped with an extension / contraction amount detector that detects the amount of extension of the boom, a boom receiver that is provided on the running body and on which the boom is placed at the boom storage position, and a boom stowage detector that detects that the boom is placed on the boom receiver, and it is preferable that the boom position determination device determines that the boom is at the predetermined position when the boom stowage detector detects that the boom has been placed on the boom receiver and when the extension / contraction amount detector detects that the amount of extension of the boom is within a range from a fully retracted state to a predetermined extension amount.

[0010] In addition, in a crane vehicle of the above configuration, it is preferable to provide a boom hoisting angle detector for detecting the boom hoisting angle, and the boom position determination device determines that the boom is in the predetermined position when the boom hoisting angle detector detects that the boom hoisting angle is within the range from a maximum value to a predetermined angle and the boom extension amount detector detects that the boom extension amount is within the range from a fully contracted state to a predetermined extension amount. Effect of the Invention

[0011] In the crane vehicle of the present invention, when the boom position determination device has determined that the boom is in a predetermined position and the winch control device is causing the winch device to perform a winding operation in response to the operation of the operation device, if the tension detection device detects that the tension in the wire has exceeded a predetermined value, the winding operation of the winch device is stopped regardless of the operation of the operation device. This makes it possible to prevent the hook from being pressed against the boom head with more force than necessary or excessive tension from being applied to the wire due to the winding operation of the winch device during hook storage work.

[0012] In addition, the crane vehicle having the above-mentioned configuration is provided with a gap detection device that detects when the gap between the boom head and the hook reaches a predetermined gap, and the winch control device is operated in response to the operation of the operation device. However, if the boom position determination device determines that the boom is in a predetermined position, the winch device may continue to wind up the wire, and if the tension detection device detects that the tension in the wire has reached a predetermined value or more, the winch device may stop winding up the wire. With this configuration, even if the interval between the boom head and the hook reaches a predetermined interval while the hook is being stored, the winch device stops winding up the wire and thereafter, there is no need to operate the winch device to wind up the wire again, which makes it possible to improve work efficiency without complicating the hook storage work. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a left side view of a pole hole digging vehicle according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is an explanatory diagram for explaining the configuration of the boom head and hook block of the above-mentioned pole hole digging vehicle. [Diagram 3] A block diagram showing the configuration of various actuators of the above-mentioned pole hole digging vehicle and a controller that controls the drive of the actuators. [Figure 4] FIG. 4 is a right side view of a pole hole digging vehicle according to a second embodiment of the present invention. [Diagram 5] 10 is an explanatory diagram for explaining the drive control of the winch device during the storage operation of the hook of the above-mentioned pole hole digging vehicle. FIG. [Figure 6] 10 is an explanatory diagram for explaining the drive control of the winch device during the storage operation of the hook of the above-mentioned pole hole digging vehicle. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. [First embodiment] First, the configuration of a pole hole digging vehicle 1, which is a first embodiment of a crane vehicle according to the present invention, will be described with reference to Fig. 1. Fig. 1 is a left side view of the pole hole digging vehicle 1 of this embodiment. In Fig. 1, the side of the driver's cabin 3, which will be described later, is referred to as the "front", and the opposite side is referred to as the "rear". Additionally, the right side of the pole hole digging vehicle 1 as it moves forward is referred to as the "right", and the left side is referred to as the "left".

[0015] As shown in Fig. 1, the post hole digger 1 of this embodiment has a driver's cabin 3 at the front of the 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 body 2. Jacks 9 for lifting and supporting the body 2 are arranged at four locations on the front, rear, left and right of the body 2. Each jack 9 lifts and supports the body 2 by driving a jack cylinder (not shown) provided inside it to extend downward, thereby bringing the entire body 2 into a stable state.

[0016] A swivel base 10 configured to be horizontally rotatable around a vertical axis is provided in the mounting area on the rear side of the vehicle body 2, and is rotated in the horizontal direction by driving a swivel motor 11. The base end of a boom 12 is pivotally supported on the swivel base 10 so that it can swing (raise and lower). The boom 12 is configured by combining a base boom 12a, an intermediate boom 12b, and a tip boom 12c in a nested manner, in that order from the swivel base 10 side, and the boom 12 is extended and lowered in the axial direction (longitudinal direction) by driving a telescopic cylinder 13 provided inside. A hoisting cylinder 14 is provided between the base boom 12a and the swivel base 10, and by driving the hoisting cylinder 14 to extend and lower, the tip of the boom 12 can be raised and lowered in the vertical direction around the axis connecting the swivel base 10 and the base end of the boom 12. When the pole hole digger vehicle 1 is traveling, the boom 12 is placed on the boom receiver 15 (shown by the dashed line in FIG. 1) provided on the vehicle body 2. Hereinafter, the state in which the boom 12 is placed on the boom receiver 15 will be referred to as the "boom storage state."

[0017] An auger support 16 is attached to the boom 12, which can be selectively connected to either the base boom 12a or the tip boom 12c. An auger device 17 is attached to this auger support 16 via a connecting rod member 16a. The auger device 17 is used when drilling holes in the ground for erecting utility poles, and is configured with an auger screw (earth auger) 17a having a rotating shaft and blades formed to spirally wind around the rotating shaft, and an auger motor 17b that rotates the auger screw 17a. The auger motor 17b has an output shaft that is driven to rotate by hydraulic pressure, and this output shaft is connected to one end of the rotating shaft of the auger screw 17a via a reducer.

[0018] An auger storage device 18 for holding the auger device is provided on the left side of the base boom 12a. The auger storage device 18 and the auger screw 17a are connected by a wire (not shown). When the auger screw 17a is rotated to wind up the wire, the auger device 17 rotates counterclockwise in FIG. 1 around the connecting rod member 16a, and is held by the auger storage device 18 at a position where it is approximately parallel to the boom 12. On the other hand, when the auger device 17 is used, the auger device 17 is released from the auger storage device 18, and the auger screw 17a is reversed to unwind the wound wire. The auger device 17 rotates clockwise in FIG. 1 around the connecting rod member 16a, and when the auger screw 17a becomes vertical, the wire is removed from the auger screw 17a. Then, by rotating the auger screw 17a, a hole can be dug in the ground for erecting a pole-like object such as a utility pole.

[0019] A winch device 20 is attached to the upper surface of the base end of the base boom 12a. The winch device 20 has a drum around which the wire 21 is wound and a winch motor 20a (see FIG. 3), which will be described later, and the winch motor 20a is driven to rotate the drum to wind or pay out the wire 21. A boom head 30 is provided at the tip of the tip boom 12c. The tip of the wire 21 pulled out from the winch device 20 passes through the inside of the boom head 30 and extends from the bottom of the boom head 30, and after the hook block 33 is suspended by the wire 21, it re-enters the inside of the boom head 30 and is fixed there.

[0020] The swivel base 10 is provided with an operation device 19 equipped with operation levers for operating the swivel operation of the swivel base 10, the extension and extension operation and hoisting operation of the boom 12, the rotation operation of the auger device, and the winding / paying out operation of the winch device 20. In addition, a hydraulic oil tank 40 is provided below the vehicle body 2, between the front jack 9 and the rear wheels 5, and the hydraulic oil tank 40 stores hydraulic oil to be supplied to hydraulically operated actuators (hereinafter referred to as "hydraulic actuators"), such as the swivel motor 11, the telescopic cylinder 13, the hoisting cylinder 14, the auger motor 17b, and the winch motor 20a provided on the winch device 20.

[0021] Next, the structure of the boom head 30 and the hook block 33 will be described with reference to FIG. 2(a). Inside the boom head 30, a boom sheave 31 and a top sheave 32 are attached so as to be rotatable about their respective shafts. The wire 21 drawn out from the winch device 20 along the boom 12 enters the inside of the boom head 30, is wound around the boom sheave 31, is further wound around the top sheave 32, and extends downward from the bottom of the boom head 30. The wire 21 extending from the bottom of the boom head 30 is wound around a hook sheave 33a attached inside the hook block 33 so as to be rotatable about a shaft, and extends upward from the top of the hook block 33. The tip of the wire 21 is bent round and processed into a ring shape, and this ring-shaped part is fixed to an end pin (not shown) provided inside the boom head 30. A hook 33b for lifting an object to be transported is attached to the bottom of the hook block 33.

[0022] An overwinding detector 35 is provided inside the boom head 30. The overwinding detector 35 is a normally-closed type limit switch having a switch arm 35a. Normally, the switch arm 35a is biased by a spring inside the overwinding detector 35 so as to tilt in the direction of arrow A (on side) in FIG. 2(a), thereby keeping the switch arm 35a in the on state. One end of a weight hanging rope 36 is connected to the switch arm 35a, and the other end of the weight hanging rope 36 is connected to a weight 37 attached to the wire 21. The weight 37 has a substantially hemispherical shape, and a through hole is opened in the center thereof for passing the wire 21 therethrough, thereby allowing the weight 37 to move up and down along the wire 21.

[0023] As described above, since the other end of the weight hoisting rope 36 is connected to the weight 37, in the state shown in Fig. 2(a), the switch arm 35a is tilted to the OFF side against the bias of the spring due to the weight of the weight 37. Then, as the wire 21 is wound by the winch device 20 shown in Fig. 1, the hook block 33 rises and eventually comes into contact with the weight 37 as shown in Fig. 2(b). If the hook block 33 rises further from this state, the weight 37 is lifted along the wire 21, and accordingly the switch arm 35a is gradually tilted in the direction of the arrow A in Fig. 2(b) due to the bias of the spring, and eventually the overwinding detector 35 turns ON.

[0024] 3, a configuration for controlling the rotation operation of the swivel base 10, the extension and retraction operation and hoisting operation of the boom 12, the rotation operation of the auger device, and the winding / paying out operation of the winch device 20 in response to the operation of the operating device 19 will be described. The pole hole digging vehicle 1 comprises a hydraulic oil tank 40, a hydraulic pump 41 for supplying hydraulic oil stored in the hydraulic oil tank 40 to each hydraulic actuator, a control valve 42 for controlling the supply direction and supply amount of hydraulic oil supplied from the hydraulic pump 41 to each hydraulic actuator, and a controller 50 for controlling the control valve 42 based on an operation signal from the operating device 19 to drive and control each hydraulic actuator.

[0025] The hydraulic pump 41 is operated by the driving force of the engine 4 for driving the vehicle body 2. A power take-off mechanism 9 is incorporated in the transmission 8 of the engine 4, and when the PTO operation lever 6 in the driver's cabin 3 is operated from off to on, a mechanical portion of the power take-off mechanism 9 is operated and the driving force of the engine 4 is transmitted to the hydraulic pump 41. When the PTO operation lever 6 is operated from on to off, the driving force of the engine 4 is transmitted to the rear wheels 5 of the vehicle body 2 via the transmission 8. The control valve 42 has an electromagnetic proportional control valve V1 corresponding to the swing motor 11, an electromagnetic proportional control valve V2 corresponding to the telescopic cylinder 13, an electromagnetic proportional control valve V3 corresponding to the elevation / depression cylinder 14, an electromagnetic proportional control valve V4 corresponding to the auger motor 17b, and an electromagnetic proportional control valve V5 corresponding to the winch motor 20a.

[0026] When an operation signal output in response to the operation of each operation lever of the operation device 19 is input to the controller 50, the controller 50 outputs a command signal corresponding to the operation signal to the control valve 42, and electromagnetically drives each spool of the electromagnetic proportional control valves V1 to V5 based on the command signal. This controls the supply direction and supply amount of hydraulic oil supplied from the hydraulic pump 41 to each hydraulic actuator, and controls the drive direction and drive speed of the swing motor 11, the telescopic cylinder 13, the hoisting cylinder 14, the auger motor 17b, and the winch motor 20a. As a result, by operating the operation lever of the operation device 19, the swing operation of the swing base 10, the telescopic operation and the hoisting operation of the boom 12, the rotation operation of the auger device, and the winding / paying operation of the winch device 20 can be performed. Note that if the overwinding detector 35 shown in FIG. 2 is turned on while the winch device 20 is performing the winding operation, the controller 50 stops the drive of the winch motor 20a to temporarily stop the winding operation of the winch device 20. To continue the winding operation of the winch device 20, it is necessary to press the stop release button provided on the operation device 19.

[0027] The pole hole digging vehicle 1 is equipped with a rotation angle detector 45 that detects the rotation angle of the rotating base 10, a hoisting angle detector 46 that detects the hoisting angle of the boom 12, an extension amount detector 47 that detects the extension amount of the boom 12, a tension detector 48 that detects the tension of the wire 21, and a boom storage detector 49 that detects when the boom 12 is placed on the boom receiver 15. Detection signals indicating the detection values ​​detected by these detectors are transmitted to a controller 50. Note that these detectors can be conventional detectors having similar functions.

[0028] The controller 50 includes an operation restriction unit 51 and a boom position determination unit 52. When the controller 50 receives detection signals from the swivel angle detector 45, the hoisting angle detector 46, the extension / retraction amount detector 47, and the tension detector 48, the operation restriction unit 51 calculates the overturning moment based on each detection value. Then, when the overturning moment calculated during the operation of the boom 12 exceeds a predetermined allowable moment, the operation range of the boom 12 is restricted regardless of the operation control of the boom 12 according to the operation of the operating device 19. Also, the boom position determination unit 52 determines whether the boom 12 is in a position suitable for keeping the hook block 33 in a stable state (hereinafter referred to as the "hook storage position") based on the detection signals from the extension / retraction amount detector 47 and the boom storage detector 49.

[0029] Next, the control contents by the controller 50 when an operator performs hook storage work in the above-mentioned pole hole digging vehicle 1 will be described with reference to Fig. 2. First, when the operator operates the winch device 20 to perform a winding operation using the operating device 19 while the boom 12 is in the state shown in Fig. 2(a), the controller 50 drives the winch motor 20a to wind so that the winch device 20 performs a winding operation of the wire 21. As the wire 21 is wound up, the hook block 33 rises, and eventually, as shown in Fig. 2(b), the hook block 33 comes into contact with the weight 37, and then the weight 37 is lifted along the wire 21 by the rise of the hook block 33.

[0030] At this time, the switch arm 35a, which had been tilted to a position where the overwinding detector 35 is in the OFF state by the weight 37 connected to the weight hanging rope 36, gradually tilts to a position where the overwinding detector 35 is in the ON state due to the bias of a spring provided inside the overwinding detector 35, and when the overwinding detector 35 eventually turns to the ON state, the controller 50 temporarily stops the winding drive of the winch motor 20a, and thereafter the winch motor 20a enters a winding drive stopped state. While the winding drive is in the stopped state, even if the operation device 19 is performed to wind the wire 21 in the winch device 20, the controller 50 does not drive the winch motor 20a for winding.

[0031] On the other hand, when the winding operation of the winch device 20 is temporarily stopped due to the over-hoisting detector 35 being turned on, the operator operates the operation device 19 to fully retract the boom 12 and place the boom 12 on the boom receiver 15. As a result, the controller 50 controls the electromagnetic proportional control valve V2 to retract the telescopic cylinder 13 so that the extension amount of the boom 12 is fully retracted, and also controls the electromagnetic proportional control valves V1 and V3 to rotate the swing motor 11 and retract the hoisting cylinder 14 so that the boom 12 is placed on the boom receiver 15. Then, when the boom 12 is placed on the boom receiver 15, the boom stowing detector 49 (see FIG. 3) transmits a detection signal indicating that the boom 12 has been placed on the boom receiver 15 (hereinafter referred to as the "boom stowing signal") to the controller 50.

[0032] The boom position determination unit 52 (see FIG. 3) determines that the boom 12 is in the hook stowing position when the controller 50 receives a boom stowing signal from the boom stowing detector 49, and determines that the boom 12 is not in the hook stowing position when the controller 50 does not receive a boom stowing signal. While the boom position determination unit 52 determines that the boom 12 is in the hook stowing position, the controller 50 releases the winch motor 20a from the stop state of the winding drive and starts the operation of the operating device 1. 9, the winch motor 20a is enabled for winding drive. However, even after the winch motor 20a is released from the winding drive stop state, if the boom position determination unit 52 determines that the boom 12 is not in the hook storage position, the winch motor 20a is again stopped for winding drive. Note that the current state may be notified to the operator by, for example, displaying on a display device whether the winch motor 20a is currently in the winding drive stop state.

[0033] When the winch motor 20a is in a state where it can be driven for winding, and the operator again operates the operation device 19 to cause the winch device 20 to perform the winding operation, the controller 50 drives the winch motor 20a for winding so that the winch device 20 performs the winding operation of the wire 21. As a result, the wire 21 is wound onto the winch device 20, and when the hook block 33 rises again, the hook block 33 eventually comes into contact with the boom head 30 as shown in Figure 2(c). If the winch device 20 continues to perform the winding operation in this state, the tension in the wire 21 gradually increases.

[0034] After the winding drive of the winch device 20 is resumed, the controller 50 judges whether the tension of the wire 21 has reached a predetermined value based on the detection signal transmitted from the tension detector 48 while the winch device 20 is performing the winding operation. When the tension of the wire 21 reaches or exceeds the predetermined value, the winding drive of the winch device 20 is stopped even if the operation device 19 is performing the winding operation of the wire 21 of the winch device 20. Here, the value of the tension of the wire 21 at which the winding drive of the winch device 20 is stopped is a value of tension at which the hook block 33 is pressed against the boom head 30 to such an extent that the hook block 33 can maintain a stable state even when the pole hole digging vehicle 1 is traveling. This value of tension may be appropriately determined based on the results of a traveling test, for example.

[0035] In this way, when the boom 12 is placed on the boom receiver 15 and the controller 50 is causing the winch device 20 to perform a winding operation in response to operation by the operating device 19, if the tension detector 49 detects that the tension of the wire 21 has reached a predetermined value or above, the winding operation of the winch device 20 is stopped regardless of operation by the operating device 19, so it is possible to prevent the hook block 33 from being pressed against the boom head 30 with more force than necessary or excessive tension from being applied to the wire 21 due to the winding operation of the winch device 20 when performing hook storage work.

[0036] In addition, even if the over-winding detector 35 detects that the distance between the hook block 33 and the boom head 30 has reached a specified distance during hook storage work, the winding operation of the winch device 20 stops, and there is no need to press the stop release button provided on the operating device 19 to resume the winding operation of the winch device 20, so the hook storage work is not complicated and work efficiency is improved.

[0037] In this embodiment, as shown in Fig. 3, the controller 50 controls the electromagnetic proportional valves V1 to V5 based on a command signal from the operating device 19, but instead of the operating device 19 and the electromagnetic proportional valves V1 to V5, manual changeover valves MSV1 to MSV5 (not shown) that can manually perform valve opening and closing control similar to that of the electromagnetic proportional valves V1 to V5 may be used. For example, a manual changeover valve MSV1 is used instead of the electromagnetic proportional valve V1, a manual changeover valve MSV2 is used instead of the electromagnetic proportional valve V2, a manual changeover valve MSV3 is used instead of the electromagnetic proportional valve V3, a manual changeover valve MSV4 is used instead of the electromagnetic proportional valve V4, and a manual changeover valve MSV5 is used instead of the electromagnetic proportional valve V5. Then, an electromagnetic proportional valve that supplies and cuts off the hydraulic oil to the winch motor 20a is provided between the manual changeover valve MSV5 corresponding to the winch motor 20a and the hydraulic pump 41.

[0038] In such a configuration, the controller 50 controls the above-mentioned electromagnetic proportional valve to supply and cut off hydraulic oil to the winch motor 20a in the same manner as the control related to the winding drive of the winch device 20 during hook storage described above. Also, in this embodiment, when the boom 12 is placed on the boom receiver 15, the winding operation of the winch device 20 is stopped if the tension of the wire 21 becomes equal to or greater than a predetermined value, but the winding operation of the winch device 20 may be stopped if the extension / contraction amount of the boom 12 is within a predetermined range and the boom 12 is placed on the boom receiver 15, and the tension of the wire 21 becomes equal to or greater than a predetermined value.

[0039] [Second embodiment] Next, the configuration of a post hole digging vehicle 1', which is a second embodiment of the crane vehicle according to the present invention, will be described with reference to Figs. 4 to 6. Fig. 4 is a right side view of the post hole digging vehicle 1' of this embodiment. In the post hole digging vehicle 1' shown in Fig. 4, the same components as those in the post hole digging vehicle 1 shown in Fig. 1 are given the same reference numerals, and detailed description thereof will be omitted. In this embodiment, the configuration for controlling each hydraulic actuator is the same as that in the control block diagram shown in Fig. 3. In Fig. 4, the front-rear and left-right directions are defined as the driver's cabin 3 side as the "front" and the opposite side as the "rear". In addition, the right side of the post hole digging vehicle 1' in the forward direction is defined as the "right" and the left side as the "left".

[0040] The pole hole digging vehicle 1' of this embodiment differs from the pole hole digging vehicle 1 shown in FIG. 1 in that a bracket 22 for hooking the hook 33b is attached to the right side of the base boom 12a at a position close to the swivel base 10. The bracket 22 is a rod-shaped member bent into a U-shape, and two parts extending laterally from the front and rear ends of the longitudinal part are attached to the base boom 12a with the longitudinal part extending vertically parallel to the base boom 12a. In the pole hole digging vehicle 1 of the first embodiment, when the hook is stored, the hook block 33 is pressed against the boom head 30 to make it stable, but in the pole hole digging vehicle 1' of this embodiment, when the hook is stored, the hook 33b is hooked to the bracket 22 and then tension is applied appropriately to the wire 21 to make the hook stable.

[0041] In addition, the boom position determination unit 52 (see Figure 3) in the post hole digging vehicle 1' of this embodiment determines that the boom 12 is in the hook storage position when (A) the detection signal transmitted from the extension amount detector 47 indicates that the extension amount of the boom 12 is within the range from the fully retracted state to a predetermined extension amount, and the detection signal transmitted from the hoisting angle detector 46 indicates that the hoisting angle of the boom 12 is within the range from the maximum value to a predetermined angle, and (B) the detection signal transmitted from the extension amount detector 47 indicates that the extension amount of the boom 12 is within the range from the fully retracted state to a predetermined extension amount, and the detection signal transmitted from the boom storage detector 49 indicates that the boom 12 is placed on the boom support 15.

[0042] Hereinafter, with reference to Figures 5 and 6, the control contents by the controller 50 when the worker performs the hook storage work in the pole hole digging vehicle 1' of this embodiment will be described. First, the worker operates the operation device 19 so that the boom 12 is in the fully retracted state and the hoisting angle of the boom 12 is at the maximum angle (most raised state). As a result, the controller 50 controls the electromagnetic proportional control valves V2 and V3 (see Figure 3) to contract the telescopic cylinder 13 so that the extension amount of the boom 12 is in the fully retracted state, and also to extend the hoisting cylinder 14 so that the hoisting angle of the boom 12 is at the maximum angle.

[0043] When the boom 12 is in the fully retracted state and the boom hoisting angle of the boom 12 reaches the maximum angle, the operator stops operating the operation device 19 to stop the operation of the boom 12. At this time, the boom position determination unit 52 (see FIG. 3) determines that the detection signal sent from the extension amount detector 47 indicates that the extension amount of the boom 12 is within the range from the fully retracted state to a predetermined extension amount. Furthermore, if the detection signal sent from the hoisting angle detector 46 indicates that the hoisting angle of the boom 12 is within the range from the maximum value to a predetermined angle (if the above-mentioned condition (A) is satisfied), it is determined that the boom 12 is in the hook storage position. Here, as shown in Figure 5(a), because the boom 12 is fully retracted and the hoisting angle of the boom 12 is at the maximum angle, it becomes easy for the operator to hook the hook 33b onto the bracket 22 even if the weight of the hook bracket 33 is heavy.

[0044] When the operator operates the winch device 20 to perform a winding operation using the operating device 19 after the hook 33b is hooked onto the bracket 22, the controller 50 drives the winch motor 20a to wind the wire 21 so that the winch device 20 performs the winding operation. As a result, the wire 21 that was hanging down from the boom head 30 as shown in FIG. 5(a) gradually becomes taut in a straight line as shown in FIG. 5(b). In addition, since the boom position determination unit 52 has determined that the boom 12 is in the hook storage position, when the controller 50 determines that the tension of the wire 21 has reached a predetermined value based on the detection signal transmitted from the tension detector 48 while the winch motor 20a is being driven to wind the wire 21 so that the winch device 20 performs the winding operation, the controller 50 stops the winding drive of the winch motor 20a regardless of the operation using the operating device 19.

[0045] Here, the value of the tension of the wire 21 at which the winding drive of the winch device 20 is stopped is set to a value of tension at which the hook block 33 with the hook 33b hooked on the bracket 22 can be kept stable without swinging even when the pole hole digging vehicle 1 is traveling. This value of tension may be appropriately determined based on the results of a traveling test, for example.

[0046] When the winding drive of the winch device 20 stops in the state shown in FIG. 5(b), the operator operates the operation device 19 to place the boom 12 on the boom receiver 15 while the boom 12 is in the fully retracted state. As a result, the controller 50 controls the electromagnetic proportional control valves V1 and V3 to drive the swing motor 11 and the hoisting cylinder 14 so that the boom 12 is placed on the boom receiver 15 as shown in FIG. 6(a). Then, when the boom 12 is placed on the boom receiver 15, the boom stowing detector 49 (see FIG. 3) transmits a boom stowing signal to the controller 50. As a result, the boom position determination unit 52 determines that the boom 12 is in the hook stowing position if the detection signal transmitted from the extension amount detector 47 indicates that the extension amount of the boom 12 is within a range from the fully retracted state to a predetermined extension amount and if the boom position determination unit 52 receives a boom stowing signal from the boom stowing detector 49 (if the above-mentioned condition (B) is satisfied),

[0047] Here, as shown in FIG. 5(b), the wire 21 that was stretched in a straight line between the boom bed 30 and the hook block 33 may become slack as shown in FIG. 6(a) by moving the boom 12 to the position of the boom receiver 15. Therefore, the worker operates the operation device 19 to cause the winch device 20 to perform a winding operation in order to re-tension the slackened wire 21. This causes the controller 50 to perform winding drive of the winch motor 20a so that the winch device 20 performs a winding operation of the wire 21. As a result, the wire 21 that was slack as shown in FIG. 6(a) gradually becomes stretched in a straight line as shown in FIG. 6(b).

[0048] At this time, since the boom position determination unit 52 has determined that the boom 12 is in the hook storage position, when the winch device 20 is driving the winch motor 20a to wind up the wire 21, the controller 50 stops the winding drive of the winch motor 20a regardless of operation by the operating device 19 when it determines based on the detection signal transmitted from the tension detector 48 that the tension of the wire 21 has reached a predetermined value.

[0049] As described above, the wire 21 is fixedly attached to the hook 33b while the hook 33b is attached to the bracket 22. By applying tension, even when the hook is stored, it is possible to prevent the hook 33b from pulling the bracket 22 with more force than necessary due to the winding operation of the winch device 20, or to prevent excessive tension from being applied to the wire 21.

[0050] The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the scope of the present invention. For example, the above-described embodiment has been described with reference to a pole hole digger vehicle equipped with an auger device 17, but the present invention may be applied to a crane vehicle that does not have an auger device 17. In addition, in the above-described embodiment, the engine power is extracted by a PTO mechanism (power take-off mechanism) and used as the drive source for the hydraulic pump that supplies hydraulic oil to each hydraulic actuator, but a battery may be used as the drive source, or the present invention may be applied to a hybrid crane vehicle that is equipped with both and selectively switches between the power sources. [Explanation of symbols]

[0051] 1, 1' Anabori pillar car 2. Body 10 Swivel table 11 Swing motor 12. Boom 13 Telescopic cylinder 14. Dinghy cylinder 15 Boom support 17 Auger device 19 Operating device 20 Winch device 20a winch motor 21 Wire 22 Bracket 30 Boom Head 33 Hook Block 33b Hook 35 Overwinding detector 45 Rotation angle detector 46 Elevation angle detector 47 Expansion / contraction detector 48 Tension detector 49 Boom storage detector 50 Controller 52 Boom position determination unit

Claims

1. A movable body; A boom is provided so as to be capable of being raised and lowered with respect to the traveling body; A boom head having a sheave and provided at the tip of the boom; a winch device having a hook attached to a tip portion thereof and a wire wound around the sheave, the winch device lifting or lowering the hook suspended from the sheave by winding and unwinding the wire; an operating device for operating the winding operation and the payout operation of the winch device; a winch control device that causes the winch device to perform a winding operation or a payout operation in response to an operation of the operation device; a tension detector for detecting the tension of the wire; a boom position determination device that determines whether the boom is at a predetermined position, The winch control device includes: This crane vehicle is characterized in that when the winch device is performing a winding operation while the boom position determination device has determined that the boom is at the predetermined position, if the tension detection device detects that the tension of the wire has reached a predetermined value or greater, the winding operation of the winch device is stopped regardless of operation by the operating device.

2. a gap detection device for detecting when the gap between the boom head and the hook has reached a predetermined gap; The winch control device includes: When the boom position determination device has determined that the boom is not at the predetermined position and the winch device is performing a winding operation, if the gap detection device detects that the gap between the boom head and the hook has reached the predetermined gap, the winch device stops the winding operation regardless of the operation by the operation device, A crane truck as described in claim 1, characterized in that when the winch device is being caused to perform a winding operation while the boom position determination device has determined that the boom is at the predetermined position, if the gap detection device detects that the gap between the boom head and the hook has reached the predetermined gap, the winding operation of the winch device is maintained, and thereafter, if the tension detection device detects that the tension of the wire has reached a predetermined value or greater, the winding operation of the winch device is stopped regardless of operation by the operating device.

3. The boom has a structure that is extendable and contractable in a longitudinal direction, an extension / retraction amount detector for detecting an extension / retraction amount of the boom; a boom receiver provided on the traveling body and on which the boom is placed when the boom is at a storage position; a boom storage detector that detects that the boom is placed on the boom receiver, The boom position determination device is 3. A crane truck as claimed in claim 1 or 2, characterized in that when the boom storage detector detects that the boom has been placed on the boom receiver and when the extension / contraction amount detector detects that the extension / contraction amount of the boom is within a range from a fully contracted state to a predetermined extension amount, it is determined that the boom is present at the predetermined position.

4. a boom hoisting angle detector for detecting a boom hoisting angle, The boom position determination device is When the boom hoisting angle detector detects that the boom hoisting angle is within a range from a maximum value to a predetermined angle, and when the boom extension amount detector detects that the boom extension amount is within a range from a fully contracted state to a predetermined extension amount, the boom is moved to the predetermined position. The crane vehicle according to claim 3, characterized in that it is determined that the vehicle is in a position where the crane vehicle is located.

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