JP4731934B2 - Telescopic boom wire cutting detection device - Google Patents

Description

  The present invention relates to a wire cutting detection device for a telescopic boom used for an aerial work vehicle or the like.

  The telescopic boom used for an aerial work vehicle, for example, has a base end pivotally attached to a swivel mounted on the body of an aerial work vehicle and is moved up and down by a hoisting cylinder. Yes. Such a telescopic boom is configured to be telescopically movable by, for example, combining a plurality of booms in a nested manner and using a built-in telescopic cylinder. A work table is attached to the tip of the telescopic boom, and the work table can be moved to a desired height by moving the telescopic boom to extend and retract.

  The telescopic boom is provided with a boom length detection device that detects the length of the telescopic boom. This boom length detection device includes, for example, a wire having one end connected to a proximal boom and the other end connected to a tip boom, a wire winder having a drum capable of winding or feeding the wire, and a wire The length detector for detecting the feeding length of the main body is mainly configured. Then, the wire is wound or unwound as the telescopic boom moves, and the length detector detects the rotational displacement of the drum that rotates by winding or unwinding the wire and outputs it as a boom length signal. ing.

Further, the boom length detection device is provided with means for detecting an error (failure) of the boom length detection device such as cutting of a wire. As a method of detecting an error of the boom length detection device, for example, there is a method of detecting an error in software when the wire feed length detected in a predetermined state becomes shorter than the wire feed length in the initial setting. In addition, for example, when the wire is cut, the drum is excessively rotated and the internal sensor is damaged. There is also a method for detecting the breakage of the wire.
JP 2001-139280 A

  However, in the boom length detection device having the above-described configuration, for example, when wire breakage is detected by always passing an electric current through an electric wire arranged inside the wire, depending on the cut state of the wire, There is a possibility that the electric wire may be energized, and there is a possibility that the accuracy of detecting the cutting of the wire is lowered.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a wire cutting detection device for a telescopic boom that can detect wire cutting more reliably. In addition, although the prior patent document regarding the wire cutting | disconnection detection apparatus of the telescopic boom which concerns on this invention was not found, the overload prevention apparatus of the construction machine which has a structure close | similar to a wire cutting | disconnection detection apparatus is disclosed by patent document 1. FIG.

To achieve such an object, the telescopic boom wire cutting detection device according to the present invention,
A wire cutting detection device in a boom length detection device that detects a length of a telescopic boom configured to be telescopically movable by a built-in telescopic cylinder by combining a plurality of booms in a nested manner ,
The boom length detection device includes a wire whose tip is connected to a boom other than the base boom that constitutes a plurality of booms, and a base end boom, and the base end of the wire is connected to extend and retract the telescopic boom. with the winding or unwinding can drum and the wire, the rotation urging device rotating urging the drum in the winding direction of the wire (e.g., a spiral spring 25 in the embodiment) and a wire winder having,
The wire disconnection detection device is disposed in a position proximal to the wire winder of definitive to the boom base, wire fed proximally from the wire winder is wound around reversing the direction a sheave which is extended distally to hold the sheave mounted swingably boom base, under tension of the wire produced based on rotational bias of the rotation urging device, always predetermined use position to a swing member which swings, the swing biasing device applying oscillating member urging force to swing in the opposite direction to the direction that swings under tension of the wire to the swing member (e.g., in the embodiment a torsion coil spring 37), provided on the boom base, when cutting the wire, a predetermined detection swing member which holds the sheaves, positioned proximally by the urging force of the swing biasing device from the predetermined position of use detects that the swings in the position Dynamic detector (e.g., the shaking motion detecting switch 40 in the embodiment) becomes provided with a.

  According to the first aspect of the invention, when the wire is cut, the wire tension does not act on the sheave and the swinging member around which the wire is wound, and the swinging member that holds the sheave is the swing biasing device. In response to the urging force, it swings to a position displaced from the predetermined use position. Then, since the swing detector detects whether or not the swing member is swung to the position displaced from the predetermined use position, it is possible to detect the wire breakage more reliably.

  Further, in the first invention, the wire is drawn out from the wire winder to the proximal end side, and the wire drawn out to the proximal end side is wound around the sheave to reverse the direction and extend to the distal end side. By doing so, the tension of the wire surely acts on the swinging member that holds the sheave, so that it is possible to prevent erroneous detection in the detection of the cut of the wire.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows an aerial work vehicle 1 equipped with a wire cutting detection device for a telescopic boom according to the present invention. This aerial work vehicle 1 is capable of traveling with front and rear wheels 3a and 3b, and is constructed based on a truck vehicle having a driving cabin 2a at the front. On the vehicle body 2 of the truck vehicle, there is disposed a turntable 4 which is driven by a turn motor (hydraulic motor) (not shown) so as to be able to turn horizontally. A telescopic boom 5 is attached to the swivel base 4 by pivoting the base end, and the telescopic boom 5 is moved up and down by a hoisting cylinder 6. The telescopic boom 5 is configured to be telescopically movable by a built-in telescopic cylinder 7 by combining a base boom 5a, an intermediate boom 5b, and a distal boom 5c in a nested manner. The telescopic boom 5 is configured such that the intermediate boom 5b and the tip boom 5c simultaneously expand and contract (relative to the base boom 5a and the intermediate boom 5b) as the telescopic cylinder 7 expands and contracts.

  The tip boom 5c has a boom head 5d at the tip, and is pivotally connected to the boom head 5d and attached to the support member 8 so as to be swingable up and down. The support member 8 has a vertical post portion (not shown), and swinging control of the support member 8 is performed by a leveling cylinder (not shown) disposed between the boom head 5d and the support member 8. Regardless of whether the boom 5 is raised or lowered, the support member 8 is controlled to swing so that the vertical post portion always extends vertically. In this way, the work table 9 is attached to the vertical post portion that is always held vertically so as to be able to turn horizontally (swing freely), and the work table 9 is always held horizontally regardless of the undulation of the boom 5.

  In addition, the outriggers 10 that are telescopically extendable downward are provided at four locations on the front, rear, left, and right of the vehicle body 2 so that when working at a high place, the vehicle body 2 can be lifted and supported as shown in the figure. It has become.

  The aerial work vehicle 1 schematically configured as described above is provided with a boom length detection device 20 for detecting the length of the telescopic boom 5 and a wire cutting detection device 19 according to the present invention. The boom length detection device 20 and the wire cutting detection device 19 of the first embodiment will be described with reference to FIG. The boom length detection device 20 includes a wire 21 having a proximal end connected to the proximal boom 5a and a distal end connected to the intermediate boom 5b, a wire winder 22 capable of winding or unwinding the wire 21, and a wire It is mainly composed of a potentiometer 26 provided in the winder 22. The wire cutting detection device 19 is mainly composed of a sheave 28 around which the wire 21 fed from the wire winder 22 is wound, a swinging member 30 that holds the sheave 28, and a swing detection switch 40. Is done.

  As shown in FIG. 3, the wire winder 22 is mainly composed of a drum 24 that can wind or unwind the wire 21 and a case 23 that rotatably accommodates the drum 24. As shown in FIG. At the same time, it is attached to the side portion of the bracket 15 fixed to the upper surface on the proximal side of the proximal boom 5a. As shown in FIG. 3, the drum 24 is formed in a cylindrical shape and is rotatably accommodated in the case 23, and the base end of the wire 21 is connected so that the wire 21 can be wound or fed out. A spiral spring 25 is attached to the inside of the drum 24 so as to urge the drum 24 in the winding direction of the wire 21.

  In addition, a potentiometer 26 for detecting the feeding length of the wire 21 is attached inside the case 23. The potentiometer 26 is connected to the drum 24 via a gear mechanism 27, detects the rotational displacement of the drum 24, and outputs it to the controller 45 (see FIG. 5).

  As shown in FIG. 1, the swing member 30 includes a swing shaft portion 31 formed in a cylindrical shape, a swing arm portion 32 formed on the outer periphery of the tip of the swing shaft portion 31, and a swing shaft portion. The sensor dog 33 formed on the outer peripheral part of the center 31 is mainly constituted, and the swinging member fixing bolt 35 is passed through the swinging shaft part 31 and fixed to the side of the bracket 15 by screws. The member 30 is attached to the side portion of the bracket 15 so as to be swingable within a vertical plane. The swing member 30 is positioned on the proximal side with respect to the wire winder 22 in the proximal boom 5a.

  The swing arm portion 32 is formed in a plate shape extending downward in the vertical plane from the outer peripheral portion of the tip end of the swing shaft portion 31, and swings about the swing shaft portion 31 as a swing shaft. . The sensor dog 33 is formed in a plate shape that protrudes in the radial direction from the central outer peripheral portion of the swing shaft portion 31, and swings about the swing shaft portion 31 as a swing shaft. Note that the direction of the swing shaft portion 31 is perpendicular to the extending direction of the wire 21.

  A sheave 28 is rotatably mounted and held at the distal end portion (the swing side end portion) of the swing arm portion 32 using a sheave mounting nut 36 and the like, and the proximal boom is extended from the drum 24 of the wire winder 22. The wire 21 fed out to the base end side of 5a is hung around the sheave 28 to reverse the direction, and is extended to the front end side of the base end boom 5a (that is, toward the intermediate boom 5b). Yes. The sheave 28 held by the swing member 30 is located at a position facing the proximal edge of the proximal boom 5a (that is, proximal to the wire winder 22). The wire 21 drawn out from the wire winder 22 passes through the upper (outer) side of the proximal boom 5a until reaching the sheave 28, and after the direction is reversed by the sheave 28, the inner side of the proximal boom 5a. Is supposed to pass through.

  Then, the swing member 30 holding the sheave 28 around which the wire 21 is wound receives the tension of the wire 21 generated based on the rotational biasing force of the spiral spring 25 and swings clockwise in FIG. As shown in FIG. 1, it is always oscillated and displaced to a predetermined use position. A stopper 38 is attached to the side of the bracket 15 so as to be positioned above the swinging member 30. When the swinging member 30 reaches a predetermined use position, the sensor dog 33 of the swinging member 30 is moved to the stopper 38. The swinging member 30 stops at a predetermined use position while receiving the tension of the wire 21.

  In addition, a torsion coil spring 37 is attached to the proximal end side of the swing shaft portion 31, and in a direction opposite to the direction in which the swing member 30 swings under the tension of the wire 21 (that is, the opposite direction in FIG. A biasing force that swings (clockwise) is applied to the swing member 30. The biasing force applied by the torsion coil spring 37 to the swing member 30 is set to be smaller than the tension of the wire 21 that the swing member 30 receives.

  The swing detection switch 40 is a so-called roller lever type micro switch, and is attached to the distal end side of the swing member 30 in the side portion of the bracket 15. Then, the swinging member 30 receives the biasing force of the torsion coil spring 37 and swings counterclockwise in FIG. 1, and swings to a predetermined detection position located on the base end side from the predetermined use position as shown in FIG. When displaced, the sensor dog 33 of the swing member 30 presses and swings the switch lever 41 of the swing detection switch 40 so that the swing member 30 stops at a predetermined detection position while receiving the biasing force of the torsion coil spring 37. It has become. The swing detection switch 40 outputs a disconnection detection signal to the controller 45 when the switch lever 41 swings and is turned on.

  As shown in FIG. 5, the potentiometer 26 and the swing detection switch 40 are electrically connected to a controller 45. The controller 45 includes a rotational displacement detection signal from the potentiometer 26 and a swing detection switch. A disconnection detection signal from 40 is input. When the rotational displacement detection signal is input from the potentiometer 26, the controller 45 calculates the feeding length of the wire 21 based on the rotational displacement amount of the drum 24 in the rotational displacement detection signal, and the calculated feeding length of the wire 21. Based on this, the length of the telescopic boom 5 is calculated. Further, when the disconnection detection signal is input from the swing detection switch 40, the controller 45 outputs, for example, an alarm operation signal for causing the alarm device 46 to perform an alarm operation, or, for example, the hoisting cylinder 6 or the expansion cylinder 7 A boom extension operation restriction signal is output to a boom actuator 47 configured to include

  In the boom length detection device 20 and the wire cutting detection device 19 according to the first embodiment configured as described above, the swing member 30 that holds the sheave 28 has the rotational biasing force of the spiral spring 25 as described above. Under the tension of the wire 21 generated in the base, as shown in FIG. 1, it is always oscillated and displaced to a predetermined use position. The boom length detector 20 detects the length of the telescopic boom 5 with the swing member 30 swinging and displaced to the predetermined use position.

  Specifically, the wire 21 is wound or delivered by the drum 24 as the telescopic boom 5 expands and contracts, and the potentiometer 26 detects the rotational displacement amount of the drum 24 rotated by the winding or feeding of the wire 21. A rotational displacement detection signal is output to 45. When a rotational displacement detection signal is input from the potentiometer 26 to the controller 45, the controller 45 calculates the feeding length of the wire 21 based on the input rotational displacement amount of the drum 24, and the calculated feeding of the wire 21. Based on the length, the length of the telescopic boom 5 is calculated.

  At this time, when the wire 21 is cut, the wire cutting detection device 19 detects the cutting of the wire 21. Specifically, when the wire 21 is cut, the tension of the wire 21 does not act on the sheave 28 and the swinging member 30 around which the wire 21 is wound, and the swinging that holds the sheave 28 as shown in FIG. The member 30 receives the urging force of the torsion coil spring 37 and swings and displaces to a predetermined detection position. When the swing member 30 swings and displaces to a predetermined detection position, the sensor dog 33 of the swing member 30 presses the switch lever 41 of the swing detection switch 40, and the swing detection switch 40 is turned on, so that the swing detection is performed. The switch 40 outputs a disconnection detection signal to the controller 45. Thereby, the cutting | disconnection of the wire 21 can be detected more reliably.

  Further, even when the wire 21 is cut and caught on a structure or the like in the telescopic boom 5, the tension of the wire 21 does not temporarily act on the sheave 28 and the swinging member 30, and the swinging member 30 is connected to the torsion coil spring 37. Since the oscillating force is received and oscillated to a predetermined detection position, the cutting of the wire 21 can be detected more reliably. Further, as shown in FIG. 1, the wire 21 fed out from the wire winder 22 to the proximal end side of the proximal boom 5a is wound around the sheave 28 and reversed in direction to be moved toward the distal end side of the proximal boom 5a. As a result, the tension of the wire 21 surely acts on the swinging member 30 holding the sheave 28, so that it is possible to prevent erroneous detection in the detection of cutting of the wire 21.

  When a disconnection detection signal is input from the swing detection switch 40 to the controller 45, for example, the controller 45 outputs an alarm activation signal to the alarm device 46, whereby the alarm operation by the alarm device 46 is performed. The controller 45 outputs a boom extension operation restriction signal to the boom actuator 47, whereby the extension action of the telescopic boom 5 is restricted.

  According to the wire cutting detection device 19 of the first embodiment configured as described above, when the wire 21 is cut, the tension of the wire 21 acts on the sheave 28 and the swing member 30 around which the wire 21 is wound. Accordingly, the rocking member 30 holding the sheave 28 is rocked and displaced to the predetermined detection position displaced from the predetermined use position by receiving the biasing force of the torsion coil spring 37. Then, since the swing detection switch 40 detects whether or not the swing member 30 is swung to the predetermined detection position, the cutting of the wire 21 can be detected more reliably.

  Further, the wire 21 fed from the wire winder 22 to the proximal end side (of the proximal boom 5a) is hung on the sheave 28 so as to reverse the direction and extend to the distal end side, Since the tension of the wire 21 surely acts on the swing member 30 holding the sheave 28, it is possible to prevent erroneous detection in the detection of cutting of the wire 21.

  In the first embodiment described above, the torsion coil spring 37 is used to apply a biasing force to the swing member 30 that swings in the direction opposite to the swing direction in response to the tension of the wire 21. However, the present invention is not limited to this. For example, a tension coil spring or the like may be used.

  In the first embodiment described above, the swing detection switch 40 is turned on when the swing member 30 swings to the predetermined detection position. However, the present invention is not limited to this. The rocking detection switch 40 may be configured to be turned off when the rocking member 30 is rocked and displaced to a predetermined detection position.

  Next, the boom length detection device 70 and the wire cutting detection device 69 of the second embodiment will be described with reference to FIG. The boom length detection device 70 includes a wire 21 having a proximal end connected to the proximal boom 5a and a distal end connected to the intermediate boom 5b, a wire winder 22 capable of winding or unwinding the wire 21, and a wire It is mainly composed of a potentiometer 26 provided in the winder 22. The wire cutting detection device 69 is mainly composed of a sheave 78 around which the wire 21 fed from the wire winder 22 is wound and a swing detection switch 80.

  Note that the wire 21, the wire winder 22, and the potentiometer 26 that are configured in the boom length detection device 70 of the second embodiment have the same configuration as that of the first embodiment, and are assigned the same numbers. The description is omitted. Moreover, the wire winder 22 in 2nd Embodiment is attached to the side part of the bracket 75 fixedly provided by the base end side upper surface of the base end boom 5a, as shown in FIG.

  The swing detection switch 80 is a so-called lever-type limit switch, and is mainly composed of a switch body 81 attached to a side portion of the bracket 75 and a switch lever 82 swingable with respect to the switch body 81. . In addition, the rocking | swiveling detection switch 80 is located in the base end side from the wire winder 22 in the base end boom 5a. The switch lever 82 is formed in a plate shape extending downward in the vertical plane, and is connected to a swing shaft 83 provided in the switch body 81. The direction of the swing shaft portion 83 is perpendicular to the extending direction of the wire 21.

  A sheave 78 is rotatably attached to and held at the distal end portion (swing end portion) of the switch lever 82 by using a sheave attachment nut 86 or the like. The wire 21 fed out to the base end side is wound around the sheave 78 to reverse the direction, and is extended to the front end side of the base end boom 5a (that is, toward the intermediate boom 5b). The sheave 78 held by the switch lever 82 is positioned at a position (that is, the base end side from the wire winder 22) facing the base end side upper edge portion of the base end boom 5a. The wire 21 drawn out from the wire winder 22 passes through the upper (outer) side of the proximal boom 5a until reaching the sheave 78, and after the direction is reversed by the sheave 78, the wire 21 passes through the inner side of the proximal boom 5a. It has come to pass.

  Then, the switch lever 82 holding the sheave 78 around which the wire 21 is wound receives the tension of the wire 21 generated based on the rotational biasing force of the spiral spring 25, and swings clockwise in FIG. As shown in FIG. 3, the oscillating displacement is always made at a predetermined use position. A stopper 88 is attached to the side of the bracket 75 so as to be positioned below the switch body 81. When the switch lever 82 reaches a predetermined use position, the stopper 88 abuts against the stopper 88, and the switch lever 82 is connected to the wire 21. It stops at a predetermined use position while receiving the tension.

  Further, the switch body 81 incorporates a swing biasing spring (not shown) such as a coil spring, and in the direction opposite to the direction in which the switch lever 82 swings under the tension of the wire 21 (that is, FIG. 6 is applied to the swing shaft 83 and the switch lever 82. The biasing force of the swing biasing spring is set to be smaller than the tension of the wire 21 that the switch lever 82 receives.

  When the switch lever 82 receives a biasing force of a swing biasing spring (not shown) and swings counterclockwise in FIG. 6, as shown in FIG. 7, the switch lever 82 is positioned on the proximal end side from the predetermined use position. It swings and displaces to a predetermined detection position. That is, when the switch lever 82 swings and displaces to a predetermined use position, the swing detection switch 80 is turned on and outputs an ON signal to the controller 45 (see FIG. 5), and the switch lever 82 is moved to the predetermined detection position. When the rocking displacement occurs, the controller is turned off and an off signal is output to the controller 45 as a disconnection detection signal.

  As shown in FIG. 5, the potentiometer 26 and the swing detection switch 80 are electrically connected to the controller 45 as in the first embodiment. Then, when an off signal is input as a disconnection detection signal from the swing detection switch 80, the controller 45 outputs an alarm activation signal to the alarm device 46 or extends the boom to the boom actuator 47 as in the first embodiment. An operation restriction signal is output.

  In the boom length detection device 70 and the wire cut detection device 69 of the second embodiment configured as described above, the switch lever 82 of the swing detection switch 80 that holds the sheave 78 is the spiral spring 25 as described above. In response to the tension of the wire 21 generated on the basis of the rotational urging force, as shown in FIG. 6, it is always oscillated and displaced to a predetermined use position. Then, the length of the telescopic boom 5 is detected by the boom length detection device 70 in a state where the switch lever 82 is oscillated and displaced to the predetermined use position. Specifically, as in the boom length detection device 20 of the first embodiment, a rotational displacement detection signal is input from the potentiometer 26 to the controller 45, and the length of the telescopic boom 5 is calculated by the controller 45. When the switch lever 82 swings and displaces to a predetermined use position, the swing detection switch 80 is turned on and outputs an on signal to the controller 45 (see FIG. 5).

  At this time, when the wire 21 is cut, the wire cutting detection device 69 detects the cutting of the wire 21. Specifically, when the wire 21 is cut, the tension of the wire 21 does not act on the sheave 78 and the switch lever 82 on which the wire 21 is wound, and the switch lever 82 that holds the sheave 78 as shown in FIG. Receives a biasing force of a swing biasing spring (not shown) and swings and displaces to a predetermined detection position. When the switch lever 82 swings and moves to a predetermined detection position, the swing detection switch 80 is turned off and outputs an off signal to the controller 45 as a disconnection detection signal. Thereby, the cutting | disconnection of the wire 21 can be detected more reliably.

  Further, even when the wire 21 is cut and caught on a structure or the like in the telescopic boom 5, the tension of the wire 21 is temporarily not applied to the sheave 78 and the switch lever 82, and the switch lever 82 is a swing biasing spring. Since the oscillating force is received and oscillated to a predetermined detection position, the cutting of the wire 21 can be detected more reliably. Further, since the sheave 78 is attached to the distal end portion of the switch lever 82, a separate swinging member or the like is not required, and the cutting of the wire 21 can be detected more reliably without causing a significant cost increase. Further, as shown in FIG. 6, the wire 21 fed from the wire winder 22 to the proximal end side of the proximal boom 5a is wound around the sheave 78 to reverse the direction so that the wire 21 is turned to the distal end side of the proximal boom 5a. As a result, the tension of the wire 21 surely acts on the switch lever 82 holding the sheave 78, so that it is possible to prevent erroneous detection in the detection of cutting of the wire 21.

  When an off signal is input as a disconnection detection signal from the swing detection switch 80 to the controller 45, for example, the controller 45 outputs an alarm operation signal to the alarm device 46, whereby the alarm operation by the alarm device 46 is performed. For example, when the controller 45 outputs a boom extension operation restriction signal to the boom actuator 47, the extension action of the telescopic boom 5 is restricted.

  According to the wire cutting detection device 69 of the second embodiment configured as described above, when the wire 21 is cut, the tension of the wire 21 acts on the sheave 78 and the switch lever 82 around which the wire 21 is wound. The switch lever 82 holding the sheave 78 is oscillated and displaced to a predetermined detection position displaced from the predetermined use position by receiving the urging force of the oscillating urging spring. Then, since the swing detection switch 80 detects whether or not the switch lever 82 is swung to the predetermined detection position, it is possible to detect the cutting of the wire 21 more reliably.

  Further, the wire 21 fed out from the wire winder 22 to the proximal end side (of the proximal boom 5a) is hung on the sheave 78, reversed in direction, and extended to the distal end side. Since the tension of the wire 21 surely acts on the switch lever 82 holding the sheave 78, it is possible to prevent erroneous detection in the detection of cutting of the wire 21.

  In the second embodiment described above, the swing detection switch 80 is turned off when the switch lever 82 is swung to the predetermined detection position. However, the present invention is not limited to this. The swing detection switch 80 may be turned on when the switch lever 82 is swung to a predetermined detection position.

Next, a boom length detection device 120 and a wire cut detection device 119 according to a third embodiment as a first reference example not included in the present invention will be described with reference to FIG. The boom length detection device 120 includes a wire 21 having a proximal end connected to the proximal boom 5a and a distal end connected to the intermediate boom 5b, a wire winder 22 capable of winding or unwinding the wire 21, and a wire A potentiometer 26 provided in the winder 22 and a sheave 128 around which the wire 21 fed from the wire winder 22 is wound are mainly configured. The wire cutting detection device 119 is mainly composed of a swing member 130 having a roller 131 that can come into contact with the wire 21 and a swing detection switch 140.

  Note that the wire 21, the wire winder 22, and the potentiometer 26 that are configured in the boom length detection device 120 of the third embodiment have the same configuration as that of the first embodiment, and are assigned the same numbers. The description is omitted. Moreover, the wire winder 22 in 3rd Embodiment is attached to the side part of the bracket 125 fixed to the base end side upper surface of the base end boom 5a, as shown in FIG.

  The sheave 128 is rotatably attached to and held on the side portion of the bracket 125 using a sheave attachment member 129 or the like, and the wire fed out from the drum 24 of the wire winder 22 to the proximal end side of the proximal boom 5a. 21 is hung around the sheave 128 to reverse the direction, and is extended to the distal end side of the proximal boom 5a (that is, toward the intermediate boom 5b). The sheave 128 is positioned at a position facing the proximal end side upper edge of the proximal boom 5a (that is, the proximal end side from the wire winder 22), and is fed out from the wire winder 22. The wire 21 passes through the upper (outer) side of the proximal boom 5a until reaching the sheave 128, and passes through the inner side of the proximal boom 5a after the direction is reversed by the sheave 128. .

  As shown in FIG. 8, the swing member 130 includes a swing arm part 132 whose base end is pivotally connected to a side part of the bracket 125, and a roller that is rotatably attached to the distal end of the swing arm part 132. 131, and is attached to the side of the bracket 125 using a shaft member 135 so as to be swingable within a vertical plane. The swing member 130 is positioned on the proximal side with respect to the wire winder 22 in the proximal boom 5a.

  The swing arm portion 132 is formed in a plate shape extending in the vertical plane, and swings with the center of the shaft member 135 as the swing shaft. The direction of the shaft member 135 is perpendicular to the extending direction of the wire 21. A sensor dog 133 is formed on the base end side of the swing arm portion 132 so as to be bent perpendicularly to the swing arm portion 132 and configured to be able to contact the switch lever 141 of the swing detection switch 140. The

  The roller 131 is rotatably attached to the tip end portion (the swing side end portion) of the swing arm portion 132 and is configured to be able to smoothly contact the wire 21 fed out from the drum 24 of the wire winder 22. . A spring locking portion 134 is formed in the vicinity of the roller 131 at the tip of the swing arm portion 132, and one end of the tension coil spring 136 is locked to the spring locking portion 133. .

  One end of the tension coil spring 136 is locked to the spring locking portion 133 of the swing member 130, and the other end is locked to the side portion of the bracket 125. A biasing force for swinging (clockwise in FIG. 8) is applied to the swing member 130. Then, in the state where the wire 21 is drawn out from the wire winder 22 and wound around the sheave 128, the swinging member 130 swings and is displaced while receiving the urging force of the tension coil spring 136, as shown in FIG. The roller 131 is always in contact with the upper side of the wire 21.

  The swing detection switch 140 is a so-called roller lever type micro switch, and is attached to the distal end side of the swing member 130 on the side portion of the bracket 125. As shown in FIG. 9, when the swing member 130 receives the biasing force of the tension coil spring 136 and swings and displaces beyond the position where the roller 131 contacts the wire 21, the sensor dog 133 of the swing member 130 swings. The switch lever 141 of the detection switch 140 is pressed and swung. The swing detection switch 140 outputs a disconnection detection signal to the controller 45 when the switch lever 141 swings and is turned on.

  As shown in FIG. 5, the potentiometer 26 and the swing detection switch 140 are electrically connected to the controller 45 as in the first embodiment. Then, when a disconnection detection signal is input from the swing detection switch 140, the controller 45 outputs an alarm operation signal to the alarm device 46 or a boom extension operation restriction signal to the boom actuator 47 as in the first embodiment. Is output.

  In the boom length detection device 120 and the wire cutting detection device 119 according to the third embodiment configured as described above, the wire 21 is fed from the wire winder 22 and wound around the sheave 128 as described above. In this state, as shown in FIG. 8, the swing member 130 is swung and displaced while receiving the urging force of the tension coil spring 136, so that the roller 131 is always in contact with the upper side of the wire 21. Then, with the roller 131 in contact with the upper side of the wire 21, the length of the telescopic boom 5 is detected by the boom length detection device 70. Specifically, as in the boom length detection device 20 of the first embodiment, a rotational displacement detection signal is input from the potentiometer 26 to the controller 45, and the length of the telescopic boom 5 is calculated by the controller 45.

  At this time, when the wire 21 is cut, the wire cutting detection device 119 detects the cutting of the wire 21. Specifically, when the wire 21 is cut, one end side of the cut wire 21 is taken up by the wire winder 22, and at this time, the portion with which the roller 131 is in contact is also taken up and disappears. As shown in FIG. 9, the swinging member 130 having the roller 131 receives the biasing force of the tension coil spring 136 and swings and displaces beyond the position where the roller 131 is in contact with (being in contact with) the wire 21. When the swing member 130 receives the biasing force of the tension coil spring 136 and swings and displaces beyond the position where the roller 131 comes into contact with the wire 21, the sensor dog 133 of the swing member 130 moves the switch lever 141 of the swing detection switch 140. Is pressed to turn on the swing detection switch 140, and the swing detection switch 140 outputs a disconnection detection signal to the controller 45. Thereby, the cutting | disconnection of the wire 21 can be detected more reliably.

  When a disconnection detection signal is input from the swing detection switch 140 to the controller 45, for example, the controller 45 outputs an alarm activation signal to the alarm device 46, whereby the alarm operation by the alarm device 46 is performed. The controller 45 outputs a boom extension operation restriction signal to the boom actuator 47, whereby the extension action of the telescopic boom 5 is restricted.

  According to the wire cutting detection device 119 of the third embodiment configured as described above, when the wire 21 is cut, one end side of the cut wire 21 is taken up by the wire winder 22, and at this time, the roller Since the portion that 131 is in contact with is also wound up and disappears, the swinging member 130 having the roller 131 receives the biasing force of the tension coil spring 136, and the swinging displacement exceeds the position where the roller 131 contacts the wire 21. To do. Then, since the swing detection switch 140 detects whether or not the swing member 130 is swung over the position where the roller 131 is in contact with the wire 21, the wire 21 is more reliably detected. be able to.

  In the above-described third embodiment, the tension coil spring 136 is used to apply a biasing force that swings the swing member 130 in one direction to the swing member 130. However, the present invention is not limited to this. Instead, for example, a torsion coil spring or the like may be used.

  In the third embodiment, the swing detection switch 140 is turned on when the swing member 130 is swung to a predetermined detection position. However, the present invention is not limited to this. The swing detection switch 140 may be configured to be in an off state when the swing member 130 is swing-displaced to a predetermined detection position.

  Furthermore, in the third embodiment described above, the roller 131 that can come into contact with the wire 21 is attached to the distal end portion of the swing arm portion 132. However, the present invention is not limited to this, and a pin that can smoothly contact the wire 21. You may make it attach a member to the front-end | tip part of the rocking | swiveling arm part 132. FIG.

Next, a boom length detection device 170 and a wire cutting detection device 169 according to a fourth embodiment as a second reference example not included in the present invention will be described with reference to FIG. The boom length detection device 170 includes a wire 21 having a proximal end connected to the proximal boom 5a and a distal end connected to the intermediate boom 5b, a wire winder 22 capable of winding or unwinding the wire 21, and a wire It is mainly composed of a potentiometer 26 provided in the winder 22. Further, the wire cutting detection device 169 includes a sheave 178 around which the wire 21 fed from the wire winder 22 is wound, a swinging member 180 having a roller 181 that can contact the wire 21, and a swing detection switch 190. It is mainly composed.

  Note that the wire 21, the wire winder 22, and the potentiometer 26 that are configured in the boom length detection device 170 of the fourth embodiment have the same configuration as that of the first embodiment, and are assigned the same numbers. The description is omitted. Moreover, the wire winder 22 in 4th Embodiment is attached to the side part of the bracket 175 fixed to the base end side upper surface of the base end boom 5a, as shown in FIG.

  The sheave 178 is rotatably attached to and held on the side portion of the bracket 175 using a sheave attachment member 179 or the like, and the wire fed from the drum 24 of the wire winder 22 to the proximal end side of the proximal boom 5a. 21 is hung around the sheave 178 to reverse the direction, and is extended to the distal end side of the proximal boom 5a (that is, toward the intermediate boom 5b). The sheave 178 is located at a position facing the proximal end upper edge of the proximal boom 5a (that is, the proximal end side from the wire winder 22), and is fed out from the wire winder 22. The wire 21 passes through the upper (outer) side of the proximal boom 5a until reaching the sheave 178, and passes through the inner side of the proximal boom 5a after the direction is reversed by the sheave 178. .

  As shown in FIG. 10, the swinging member 180 includes a swinging arm part 182 whose central part is pivotally connected to the side part of the bracket 175, and a roller rotatably attached to one end of the swinging arm part 182. 181 and a sensor dog 183 formed at the other end of the swing arm 182, and are attached to the side of the bracket 175 using a shaft member 185 so as to be swingable within a vertical plane. The swing member 180 is positioned on the proximal side of the wire winder 22 in the proximal boom 5a.

  The swing arm portion 182 is formed in a plate shape extending in a “<” shape in the vertical plane, and a bent portion located near the center of the swing arm portion 182 uses the shaft member 185 to form the bracket 175. The one end side and the other end side of the swing arm portion 182 are swung around the center of the shaft member 185 as a swing shaft. The direction of the shaft member 185 is perpendicular to the extending direction of the wire 21.

  The roller 181 is rotatably attached to one end of the swing arm 182 and is configured to be able to smoothly contact the wire 21 fed from the drum 24 of the wire winder 22. The sensor dog 183 is formed at the other end of the swing arm 182 so as to be bent perpendicularly to the swing arm 182 and configured to be able to contact the switch lever 191 of the swing detection switch 190. .

  Further, a torsion coil spring (not shown) is attached to the shaft member 185, and a biasing force that swings the swing member 180 in one direction (clockwise in FIG. 10) is applied to the swing member 180. Yes. Then, in the state where the wire 21 is drawn out from the wire winder 22 and wound around the sheave 178, the swinging member 180 swings while receiving the urging force of a torsion coil spring (not shown) as shown in FIG. Due to the dynamic displacement, the roller 181 always comes into contact with the outer peripheral portion of the wire 21 that hangs on the sheave 178.

  The swing detection switch 190 is a so-called roller lever type micro switch, and is attached to the front end side of the swing member 180 on the side portion of the bracket 175. As shown in FIG. 11, when the swing member 180 receives a biasing force of a torsion coil spring (not shown) and swings and displaces beyond the position where the roller 181 contacts the wire 21, the sensor dog of the swing member 180 is moved. Reference numeral 183 presses the switch lever 191 of the swing detection switch 190 to swing it. The swing detection switch 190 outputs a disconnection detection signal to the controller 45 when the switch lever 191 swings and is turned on.

  As shown in FIG. 5, the potentiometer 26 and the swing detection switch 190 are electrically connected to the controller 45 as in the first embodiment. When the disconnection detection signal is input from the swing detection switch 190, the controller 45 outputs an alarm activation signal to the alarm device 46 or a boom extension operation restriction signal to the boom actuator 47 as in the first embodiment. Is output.

  In the boom length detection device 170 and the wire cutting detection device 169 of the fourth embodiment configured as described above, the wire 21 is fed from the wire winder 22 and wound around the sheave 178 as described above. In the state, as shown in FIG. 10, the swing member 180 is swung and displaced while receiving the urging force of a torsion coil spring (not shown), so that the roller 181 is always in contact with the outer peripheral portion of the wire 21 applied to the sheave 178. It is supposed to be. Then, the length of the telescopic boom 5 is detected by the boom length detection device 170 in a state where the roller 181 is in contact with the outer peripheral portion of the wire 21 that hangs on the sheave 178. Specifically, as in the boom length detection device 20 of the first embodiment, a rotational displacement detection signal is input from the potentiometer 26 to the controller 45, and the length of the telescopic boom 5 is calculated by the controller 45.

  At this time, when the wire 21 is cut, the wire cutting detection device 169 detects the cutting of the wire 21. Specifically, when the wire 21 is cut, one end side of the cut wire 21 is taken up by the wire winder 22, and at this time, the portion that the roller 181 is in contact with is also taken up and disappears. As shown in FIG. 11, the swinging member 180 having the roller 181 is swung and displaced beyond the position where the roller 181 contacts (contacts) the wire 21 due to the biasing force of the torsion coil spring. When the swing member 180 receives the biasing force of the torsion coil spring and swings and displaces beyond the position where the roller 181 contacts the wire 21, the roller 181 contacts the outer peripheral portion of the sheave 178 and the swing member 180 The sensor dog 183 presses the switch lever 191 of the swing detection switch 190 to turn on the swing detection switch 190, and the swing detection switch 190 outputs a disconnection detection signal to the controller 45. Thereby, the cutting | disconnection of the wire 21 can be detected more reliably. Furthermore, since the roller 181 is configured to come into contact with the outer peripheral portion of the wire 21 that hangs on the sheave 178, the influence of the bending of the wire 21 can be eliminated. Can do.

  When a disconnection detection signal is input from the swing detection switch 190 to the controller 45, for example, the controller 45 outputs an alarm activation signal to the alarm device 46, whereby the alarm operation by the alarm device 46 is performed. The controller 45 outputs a boom extension operation restriction signal to the boom actuator 47, whereby the extension action of the telescopic boom 5 is restricted.

  According to the wire cutting detection device 169 of the fourth embodiment configured as described above, when the wire 21 is cut, one end side of the cut wire 21 is taken up by the wire winder 22, and at this time, the roller Since the portion that has been in contact with 181 is also taken up and lost, the swinging member 180 having the roller 181 receives the biasing force of the torsion coil spring and swings and displaces beyond the position where the roller 181 contacts the wire 21. . Then, since the swing detection switch 190 detects whether or not the swing member 180 is swung over the position where the roller 181 contacts the wire 21, the wire 21 is more reliably detected. be able to. Furthermore, since the roller 181 is configured to come into contact with the outer peripheral portion of the wire 21 that hangs on the sheave 178, the influence of the bending of the wire 21 can be eliminated, thereby preventing erroneous detection in the detection of cutting of the wire 21. Can do.

  In the fourth embodiment described above, a biasing force that swings the swinging member 180 in one direction is applied to the swinging member 180 using a torsion coil spring (not shown). For example, a tension coil spring or the like may be used.

  In the fourth embodiment described above, the swing detection switch 190 is turned on when the swing member 180 is swung to the predetermined detection position. However, the present invention is not limited to this. The rocking detection switch 190 may be turned off when the rocking member 180 is rocked and displaced to a predetermined detection position.

Subsequently, a boom length detection device 220 and a wire cutting detection device 219 of a fifth embodiment as a third reference example not included in the present invention will be described with reference to FIGS. 12 and 13. The boom length detection device 220 includes a wire 21 having a proximal end connected to the proximal boom 5a and a distal end connected to the intermediate boom 5b, a wire winder 22 capable of winding or unwinding the wire 21, and a wire It is mainly composed of a potentiometer 26 provided in the winder 22. Further, the wire cutting detection device 219 includes first and second sheaves 228 and 229 around which the wire 21 fed from the wire winder 22 is wound, a swinging member 230 that holds the first sheave 228, and a swing. The movement detection switch 240 (not shown in FIG. 13) is mainly configured.

  Note that the wire 21, the wire winder 22, and the potentiometer 26 configured in the boom length detection device 220 of the fifth embodiment have the same configuration as that of the first embodiment, and are assigned the same numbers. The description is omitted. Moreover, as shown in FIGS. 12 and 13, the wire winder 22 in the fifth embodiment is attached to the proximal side surface of the proximal boom 5a, and the wire 21 faces the distal end side of the proximal boom 5a. It has come out.

  As shown in FIG. 14A, the swinging member 230 has a swinging shaft part 231 formed in a cylindrical shape and a swinging arm part 232 formed on the outer peripheral part of the swinging shaft part 231. The sensor dog 233 formed on the outer periphery of the moving shaft portion 231 is mainly configured, and the swinging member fixing bolt 235 is passed through the swinging shaft portion 231 and fixed to the upper surface side of the bracket 225 by screws. The swing member 230 is attached to the upper surface side of the bracket 225 so as to be swingable within a plane substantially parallel to the upper surface of the bracket 225 (base end boom 5a). As shown in FIGS. 12 and 13, the bracket 225 is fixed to the proximal side surface of the proximal boom 5a and extends substantially parallel to the extending direction of the proximal boom 5a. Further, the swing member 230 is positioned on the distal end side of the wire winder 22 in the proximal boom 5a.

  As shown in FIG. 14A, the swing arm portion 232 is formed in a plate shape extending from the outer peripheral portion of the swing shaft portion 231 in a plane substantially parallel to the upper surface of the bracket 225 (base end boom 5a). Thus, it swings around the swing shaft 231 as a swing shaft. The sensor dog 233 is formed in a plate shape that protrudes in the radial direction from the outer periphery of the swing shaft portion 231 and swings with the swing shaft portion 231 as the swing shaft. The direction of the swing shaft portion 231 is perpendicular to the extending direction of the wire 21.

  A first sheave 228 is rotatably attached to and held at the distal end portion (oscillation side end portion) of the swing arm portion 232, and is disposed from the drum 24 of the wire winder 22 to the distal end side of the proximal boom 5a ( The drawn wire 21 is wound around the first sheave 228 in a direction substantially parallel to the extending direction of the proximal boom 5a, and the direction is changed so as to be inclined with respect to the extending direction of the proximal boom 5a. , And extends toward the second sheave 229 (to the distal end side of the proximal boom 5a).

  Then, the swing member 230 that holds the first sheave 228 around which the wire 21 is wound receives the tension of the wire 21 that is generated based on the rotational biasing force of the spiral spring 25 and swings clockwise in FIG. As shown in FIG. 14 (a), it is always oscillated and displaced to a predetermined use position. The bracket 225 is provided with a stopper (not shown). When the swing member 230 reaches a predetermined use position, a part of the swing member 230 comes into contact with the stopper, and the swing member 230 receives the tension of the wire 21. However, it stops at a predetermined use position.

  In addition, like the swing shaft portion 31 (swing member 30) of the first embodiment, a torsion coil spring (not shown) is attached to the swing shaft portion 231, and the swing member 230 is connected to the wire 21. The swinging member 230 is applied with a biasing force that swings in the direction opposite to the swinging direction (ie, counterclockwise in FIG. 14). Note that the biasing force applied by the torsion coil spring to the swing member 230 is set to be smaller than the tension of the wire 21 received by the swing member 230.

  The second sheave 229 is rotatably mounted and held on the upper surface side of the bracket 225 (the front end side from the first sheave 228) using a sheave mounting member 239 or the like, and from the first sheave 228 to the front end side of the proximal boom 5a. The wire 21 extending toward the base is wound around the second sheave 229, changes the direction so as to be slightly inclined with respect to the extending direction of the proximal boom 5a, and extends toward the intermediate boom 5b. Yes. The wire 21 from the second sheave 229 toward the intermediate boom 5b passes through the passage hole 226 formed in the side portion of the base end boom 5a and the bracket 225 and reaches the intermediate boom 5b.

  The swing detection switch 240 is a so-called roller lever type micro switch, and is attached to the side of the swing member 230 on the upper surface side of the bracket 225 (outward with respect to the proximal boom 5a). Then, the swinging member 230 swings counterclockwise in FIG. 14 in response to the urging force of the torsion coil spring, and swings to a predetermined detection position located on the side of the predetermined use position, as shown in FIG. 14B. When it is displaced dynamically, the sensor dog 233 of the swing member 230 presses and swings the switch lever 241 of the swing detection switch 240 so that the swing member 230 stops at the predetermined detection position while receiving the biasing force of the torsion coil spring. It has become. The swing detection switch 240 outputs a disconnection detection signal to the controller 45 when the switch lever 241 swings and is turned on.

  As shown in FIG. 5, the potentiometer 26 and the swing detection switch 240 are electrically connected to the controller 45 as in the first embodiment. Then, when a disconnection detection signal is input from the swing detection switch 140, the controller 45 outputs an alarm operation signal to the alarm device 46 or a boom extension operation restriction signal to the boom actuator 47 as in the first embodiment. Is output.

  In the boom length detection device 220 and the wire cutting detection device 219 according to the fifth embodiment configured as described above, the swing member 230 that holds the first sheave 228 is provided with the rotation of the spiral spring 25 as described above. In response to the tension of the wire 21 generated based on the urging force, as shown in FIG. 14 (a), it is always oscillated and displaced to a predetermined use position. Then, the length of the telescopic boom 5 is detected by the boom length detection device 220 in a state where the swinging member 230 is swingingly displaced to the predetermined use position. Specifically, as in the boom length detection device 20 of the first embodiment, a rotational displacement detection signal is input from the potentiometer 26 to the controller 45, and the length of the telescopic boom 5 is calculated by the controller 45.

  At this time, when the wire 21 is cut, the wire cutting detection device 219 detects the cutting of the wire 21. Specifically, when the wire 21 is cut, the tension of the wire 21 does not act on the first sheave 228 and the swinging member 230 around which the wire 21 has been wound, and as shown in FIG. The rocking member 230 that holds the sheave 228 is rocked and displaced to a predetermined detection position under the urging force of a torsion coil spring (not shown). When the swing member 230 swings and displaces to a predetermined detection position, the sensor dog 233 of the swing member 230 presses the switch lever 241 of the swing detection switch 240 and the swing detection switch 240 is turned on, and the swing detection is performed. The switch 240 outputs a disconnection detection signal to the controller 45. Thereby, the cutting | disconnection of the wire 21 can be detected more reliably.

  Further, even when the wire 21 is cut and caught on a structure or the like in the telescopic boom 5, the tension of the wire 21 does not temporarily act on the sheave 28 and the swing member 230, and the swing member 230 is attached with a torsion coil spring. Since it is oscillated and displaced to a predetermined detection position in response to the force, the cutting of the wire 21 can be detected more reliably.

  When a disconnection detection signal is input from the swing detection switch 240 to the controller 45, for example, the controller 45 outputs an alarm activation signal to the alarm device 46, whereby the alarm operation by the alarm device 46 is performed. The controller 45 outputs a boom extension operation restriction signal to the boom actuator 47, whereby the extension action of the telescopic boom 5 is restricted.

  According to the wire cutting detection device 219 of the fifth embodiment configured as described above, when the wire 21 is cut, the tension of the wire 21 is applied to the first sheave 228 and the swing member 230 around which the wire 21 is wound. No longer acts, and the swinging member 230 that holds the first sheave 228 swings and displaces to a predetermined detection position that is displaced from the predetermined use position under the urging force of the torsion coil spring. Then, since the swing detection switch 240 detects whether or not the swing member 230 has been swung and displaced to a predetermined detection position, the cutting of the wire 21 can be detected more reliably.

  In the fifth embodiment described above, the torsion coil spring is used to apply an urging force to the swing member 230 to swing in the direction opposite to the swing direction in response to the tension of the wire 21. For example, a tension coil spring or the like may be used.

  In the fifth embodiment, the swing detection switch 240 is turned on when the swing member 230 is swung to the predetermined detection position. However, the present invention is not limited to this. The rocking detection switch 240 may be configured to be turned off when the rocking member 230 is rocked and displaced to a predetermined detection position.

  Further, in the above-described fifth embodiment, the swing member 230 is configured to hold the first sheave 228, but is not limited thereto, and is configured to hold the second sheave 229. Also good.

  Moreover, in each above-mentioned embodiment, although the aerial work vehicle 1 was demonstrated to the example as a work vehicle provided with the boom length detection apparatus which concerns on this invention, it is not restricted to this, For example, a crane vehicle, a hole, etc. The present invention can also be applied to a digging column car or the like.

  Furthermore, in each above-mentioned embodiment, although the expansion-contraction boom 5 is comprised from three booms, the base end boom 5a, the intermediate | middle boom 5b, and the front end boom 5c, it is not restricted to this, For example, the number of booms There may be two or five, and the telescopic boom may be configured to be telescopically movable by combining a plurality of booms in a nested manner.

  Moreover, in each above-mentioned embodiment, although comprised so that the front-end | tip of the wire 21 may be connected with the intermediate | middle boom 5b, it is not restricted to this, Even if comprised so that it may be connected with the front-end boom 5c. Good. This is particularly effective for an extendable boom configured such that the intermediate boom and the tip boom are sequentially extended and retracted as the extendable cylinder is extended and retracted.

  Furthermore, in each of the above-described embodiments, the potentiometer 26 is used to detect the feeding length of the wire 21, but the present invention is not limited to this, and for example, a rotary encoder or the like may be used. It is only necessary to be configured to be able to detect the payout length.

  In each of the above-described embodiments, a micro switch or a limit switch is used as the swing detector (swing detection switch) in the present invention. However, the present invention is not limited to this, and for example, a beam sensor or a proximity sensor. Etc. may be used.

It is a perspective view of the boom length detection apparatus and wire cutting detection apparatus in 1st Embodiment. It is a perspective view of an aerial work vehicle provided with a wire cutting detection device for a telescopic boom according to the present invention. It is a fragmentary sectional view of the wire winder comprised by a boom length detection apparatus. It is a side view of the boom length detection apparatus and wire cutting detection apparatus in 1st Embodiment. It is a block diagram which shows the outline | summary of the control system comprised in an aerial work vehicle. It is a perspective view of the boom length detection apparatus and wire cutting detection apparatus in 2nd Embodiment. It is a side view of the boom length detection apparatus and wire cutting detection apparatus in 2nd Embodiment. It is a perspective view of the boom length detection apparatus and wire cutting | disconnection detection apparatus in 3rd Embodiment as a 1st reference example not included in this invention . It is a side view of the boom length detection apparatus and wire cutting detection apparatus in 3rd Embodiment. It is a perspective view of the boom length detection apparatus and wire cutting | disconnection detection apparatus in 4th Embodiment as a 2nd reference example not included in this invention . It is a side view of the boom length detection apparatus and wire cutting detection apparatus in 4th Embodiment. It is a top view of the boom length detection apparatus and wire cutting detection apparatus in 5th Embodiment as a 3rd reference example not included in this invention . It is a side view of the boom length detection apparatus and wire cutting detection apparatus in 5th Embodiment. (A) is a top view which shows the state by which the rocking | swiveling member in 5th Embodiment was rockingly displaced to the predetermined use position, (b) is a top view which shows the state in which the rocking member was rockingly displaced to the predetermined detection position. It is.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aerial work vehicle 5 Telescopic boom 5a Base end boom 5b Middle boom 5c Front end boom 5d Boom head 19 Wire cutting | disconnection detection apparatus (1st Embodiment)
20 Boom length detection device (first embodiment)
21 Wire 22 Wire Winder 24 Drum 25 Spiral Spring (Rotation Energizing Device)
26 Potentiometer (length detector)
28 Sheave 30 Oscillating member 37 Torsion coil spring (oscillating biasing device)
40 Oscillation detection switch (Oscillation detector)
69 Wire Cutting Detection Device (Second Embodiment)
70 Boom length detection device (second embodiment)
78 Sheave 80 Oscillation detection switch (Oscillation detector)
81 Switch body 82 Switch lever (swing member)
119 Wire cutting detection device (third embodiment)
120 Boom Length Detection Device (Third Embodiment)
128 Sheave 130 Oscillating member 131 Roller (wire contact part)
136 Tension coil spring (oscillating biasing device)
140 Oscillation detection switch (Oscillation detector)
169 Wire cutting detection device (fourth embodiment)
170 Boom length detection device (fourth embodiment)
178 Sheave 180 Swing member 181 Roller (wire contact part)
190 Oscillation detection switch (Oscillation detector)
219 Wire cutting detection device (fifth embodiment)
220 Boom length detection device (fifth embodiment)
228 First sheave 230 Oscillating member 240 Oscillation detection switch (oscillation detector)

Claims (1)

A wire cutting detection device in a boom length detection device that detects a length of a telescopic boom configured to be telescopically movable by a built-in telescopic cylinder by combining a plurality of booms in a nested manner ,
The boom length detection device is:
A wire whose tip is connected to a boom other than the proximal boom constituting the plurality of booms;
A drum disposed on the base end boom, the base end of the wire being connected and capable of winding or unwinding the wire in accordance with the expansion and contraction movement of the telescopic boom, and the drum rotating in the winding direction of the wire a wire winder having a rotating biasing device for biasing,
The wire cutting detection device
Are arranged located proximal to the wire winder of definitive to the proximal boom, wherein the wire winder was fed to the proximal end side wire is wound around reversing the direction leading end side And the sheave extended to
The sieve retains swingably attached to the base end boom, under tension of the wire produced based on rotational bias of the rotation urging device, always swings to a predetermined use position A swing member;
A swinging biasing device that applies a biasing force to the swinging member to swing the swinging member in a direction opposite to the swinging direction under the tension of the wire;
Provided on the base end boom, when the cutting of the wire, a predetermined said rocking member holding the sieve is located in the proximal side from the predetermined use position under the urging force of the swing biasing device wire disconnection detection device of the telescopic boom, characterized in that it comprises a swing detector for detecting that it has swings to the detection position.

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