JP3089000U - Crane mechanism overwind prevention device - Google Patents

Abstract

(57) [Problem] To prevent an overwinding detector from being damaged even if a weight suspension rope for suspending a weight is hooked on a scaffolding bolt or an overhead wire in an overwinding prevention device. SOLUTION: A boom, a winch mechanism and a wire 25 are provided.
And an overwinding prevention device 35 provided in a crane mechanism having a hook 27 and an overwinding detector 30 attached near the tip of the boom, and a switch arm 30a of the overwinding detector 30 via an attachment member 39. Ring 51, and weight suspension rope 31 extending downward from metal ring 51
And a weight 33 attached to the lower end of the weight suspension rope 31 and lifted by the hook 27 immediately before becoming overwound.
And is provided. For example, when the weight hanging rope 31 is caught on something and is forcibly pulled during the crane operation, the metal ring 51 is extended and the weight hanging rope 31 is separated, and the overwind detector 30 is damaged. To prevent

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 TECHNICAL FIELD The present invention relates to an overwinding prevention device used for a crane mechanism of a digging pole truck on which a crane truck or a utility pole is installed.

[0002]

[Prior art]

 2. Description of the Related Art As a conventional overwinding prevention device for a crane mechanism, for example, one disclosed in FIGS. 2 and 3 of Japanese Patent Application Laid-Open No. 9-272692 is known. In this conventional example, a wire (15) fed from a winch device provided at the base end of a crane truck is hung around a point sheave (26) at the end of the boom to extend downward, and a hook (16). ) Is connected to the lower surface of the boom member (23) while supporting the same. In this crane truck, if the wire is taken up by the winch device, the hook can be lifted to lift the object suspended from the hook. At this time, the hook is overwound such that the hook contacts the boom member. It is not preferable to wind the wire until the state is reached. For this reason, this crane truck discloses an overwinding prevention device that stops the operation of the winch device before it becomes overwound to prevent the occurrence of overwinding.

[0003] The overwinding prevention device includes a limit switch (51) attached to a boom member, a support line (52) suspended from a switch arm of the limit switch, and a weight (53). The weight has a through hole, and the wire penetrates the through hole. The weight can freely move up and down along the wire, and the weight of the weight lowers the switch arm to turn off. When the wire is wound from this state and immediately before the overwinding state, the upper end of the hook pushes up the weight and the support line is slackened, and the switch arm of the limit switch moves up and this switch is turned on and immediately before the overwinding state. It is configured so that it can be detected.

[0004]

[Problems to be solved by the invention]

 Such an overwind prevention device has been used for a crane mechanism of a crane truck or a digging pole truck, but the support line is caught by a work object or the like during the work by the crane truck or the like. There is a problem that the limit switch is damaged due to the pulling. For example, when installing and moving a utility pole by lifting it using the crane mechanism of an aerial pier, the scaffolding bolt of the utility pole is caught on the support line and the support line is forcibly pulled. Can damage the limit switch. In addition, when crane work is performed by inserting a boom between the overhead wires (between wires), the support line is caught on the overhead wire and the like, and the boom is moved and the limit switch is turned on. May cause damage.

[0005] The present invention has been made in view of such a problem, and an overwinding detector is used in a case where a weight suspension means (support line) for suspending a weight (weight) is forcibly pulled. It is an object of the present invention to provide an overwinding prevention device for a crane mechanism that can prevent damage to a (limit switch).

[0006]

[Means for Solving the Problems]

 In order to achieve this object, the present invention provides a boom, a winch mechanism attached to the boom for winding and unwinding a wire, and a boom tip wound and wound out of the winch mechanism. In a crane mechanism equipped with a wire suspended from the head and a hook attached to the tip of the wire, an overwind detector attached near the boom tip and a Weight suspending means (for example, the weight suspending rope 31 in the embodiment) attached to the lower end of the weight suspending means and positioned near the wire so as to be lifted by the tip or hook of the wire immediately before becoming overwound. And an overwinding prevention device. Then, the overwinding detector is configured to detect the tension acting on the weight via the weight suspending means to detect whether or not the overwinding state occurs, and the weight suspending means receives an external force exceeding a certain level. And a connecting means having a function of separating the portion on the weight side from the portion on the overwind detector side.

[0007] Using a crane mechanism having an overwinding prevention device having such a configuration, for example, when a utility pole is lifted and its movement and installation work is performed, a weight suspension rope constituting a weight suspension means is provided. If the weight hanging rope is pulled due to being hooked on a scaffold bolt of a utility pole, the weight hanging rope is separated by the connecting means when the pulling force (external force) exceeds a certain level. As a result, an external force exceeding a certain level does not act on the overwinding detector, and damage to the overwinding detector can be prevented.

[0008] The connecting means is constituted by a metal ring made of a spirally wound wire, and the portion on the overwind detector side and the portion on the weight side are connected via the metal ring, and the portion on the weight side is fixed. When the metal ring is pulled by the above external force, the helical shape of the metal ring is elongated, and the weight-side portion can be separated from the overwind detector-side portion. With this configuration, if a large external force (tension) acts on the weight suspension rope, the metal ring extends and separates the overwind detector from the weight. Damage to the detector can be prevented.

[0009] The connecting means includes a first locking member connected to a portion on the overwind detector side and a second locking member connected to a portion on the weight side, and the first locking member and An elastic support arm is provided on one of the second locking members, and a graspable member gripped by the elastic support arm is provided on the other. When the locking member is pulled with a certain external force or more, the gripping of the gripping member by the elastic support arm is released, and the first locking member and the second locking member may be separated. Even with such a configuration, when a large external force (tension) is applied to the weight suspension rope, the first locking member and the second locking member are separated, and the external force acting on the overwind detector is cut off. Detector damage can be prevented.

[0010] Furthermore, the connecting means comprises a first locking member connected to the overwind detector side portion and a second locking member connected to the weight side portion, and the first locking member and the second locking member are connected to each other. The second locking member is fixed to the first locking member in a state where the first locking member and the second locking member are suction-connected by magnetically attracting the second locking member to the second locking member. The pulling by the above external force may release the suction connection between the first locking member and the second locking member and separate the first locking member and the second locking member. Even in such a configuration, when a large external force (tension) acts on the weight suspension rope, the first locking member and the second locking member are separated from each other as described above, and a large amount is applied to the overwinding detector. There is no external force acting, and damage to the overwind detector can be prevented.

[0011]

[Embodiment of the invention]

 Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 shows a digging column car 1 having a crane mechanism provided with an overwinding prevention device according to the present invention. This digging pole car 1 can run with wheels 5 and is based on a truck having a driving cabin 7 at the front. A turning table 11 is provided on the body 3 of the truck so as to be driven by a turning motor 10 and turn horizontally. A base end is pivotally connected to the swivel base 11 and a boom 13 is attached. The boom 13 is moved up and down by an up / down cylinder 15. The boom 13 is configured such that a base end boom 13a, an intermediate boom 13b, and a distal end boom 13c are nested and can be extended and retracted by a built-in retractable cylinder 12.

An auger mounting member 20 configured to be selectively connectable to each of the distal ends of the booms 13a and 13b and the boom head 17 is attached to the distal end of the proximal boom 13a. The earth auger device 16 is swingably attached to the auger attachment member 20. The earth auger device 16 includes an auger screw 16a and a hydraulic motor 16b for rotating the auger screw 16a. The auger screw 16a is vertically suspended from the tip of the boom 13 to rotate the auger screw 16a. Can perform ground excavation work.

A winch device 19 is attached to the upper surface of the base end portion of the boom 13. A wire 25 is wound around the winch device 19 so that the wire 25 can be unwound and wound up, and the wire 25 is moved to the boom head 17. Extending. The periphery of the boom head 17 will be described with reference to FIG. A boom sheave 21 and a top sheave 23 are rotatably arranged inside the boom head 17, and a wire 25 fed from the winch device 19 is wound around the boom sheave 21, and furthermore, inside the boom head 17. Is extended to the front end side, is wrapped around the top sheave 23, and extends downward. The wire 25 is hung around the sheave 27 a of the hook 27 to support the hook 25. The tip 25 a of the wire 25 extends upward and is connected to an end pin 29 provided in the boom head 17. In this example, the wire 25 is hung on two wires. However, in the case of an odd-numbered wire such as a three-wire, the wire tip is connected to a hook. Coupled to the boom head.

Outriggers 9 are provided at the front, rear, left, and right of the vehicle body 3 so as to be extendable and retractable. When performing pillar work, the outriggers 9 are extended downward as shown in FIG. I can do it. At the base of the swivel table 11, there is provided an operating device 14 for raising / lowering / turning / expanding / releasing the boom 13 and for operating an earth auger 16 and a lifting device which will be described later. The operation of the boom 13 is controlled by the operation of the boom 13.

An overwinding prevention device 35 is attached to the boom head 17, and this configuration will be described with reference to FIG. The overwind prevention device 35 includes an overwind detector 30, a mounting member 39, a metal ring 51 (connecting means), a weight hanging rope 31 (weight hanging means), and a weight 33. The overwind detector 30 is constituted by a limit switch, and has a switch arm 30a that performs switching by sensing the tension from the weight suspension rope 31. The switch arm 30a is normally urged upward (in the direction of arrow A) by a spring (not shown) disposed therein, and is in an on state. When the weight of the weight 33 acts via the weight suspension rope 31, It swings downward (in the direction of arrow B) and turns off. However, a stopper pin 37 is provided to prevent the switch arm 30a from swinging excessively downward. A mounting member 39 is attached to the distal end of the switch arm 30a by pin connection, and a metal ring 51 is inserted through and connected to a locking hole 39b formed in a tongue piece 39a below the mounting member 39. The metal ring 51 is formed by spirally winding a wire, and is also inserted through and connected to a locking ring 31 c formed at the upper end of the weight suspension rope 31. The metal ring 51 is configured to have such a strength that the metal ring 51 is elongated when it receives an external force exceeding a predetermined value.

A weight 33 is connected to a lower end of the weight hanging rope 31, and the weight hanging rope 31 receives gravity from the weight 33, and passes through a mounting member 39 and a metal ring 51 from the tip of the switch arm 30 a. It will be in a state of drooping. The weight 33 is provided with a through hole (not shown) at the center, and the wire 25 is penetrated through the through hole. The weight 33 can freely move up and down along the wire 25. For this reason, in a free state in which no external force acts, the gravity from the weight 33 acts on the switch arm 30a to swing downward, and the overwind detector 30 is turned off. At this time, the switch arm 30a swings downward to a position where it contacts the stopper pin 37, and is stopped and held.

In this state, the wire 25 is taken up by the winch device 19 and the hook 27 is moved upward. When the upper end 27b of the hook 27 abuts on the weight 33 and pushes it up, the hanging rope 31 is loosened, and the switch arm is loosened. Gravity from the weight 33 acting on 30a is released. Therefore, the switch arm 30a moves upward by the biasing force of the internal spring, and the overwind detector 30 is turned on. The length of the weight suspension rope 31 is set such that the weight 33 is pushed up when the hook 27 is moved upward from the lower end of the boom head 17 to a position having a predetermined safety distance. The state in which the wire 25 is wound up until the hook 27 comes into contact with the lower end of the boom head 17 is called an over-wound state. When it is moved up to a position having a distance, that is, in a state immediately before an overwind state, the overwind detector 30 is turned on. For this reason, if the winding operation of the winch device 19 is stopped when the overwind detector 30 is turned on, it is possible to prevent the overwind state from occurring in advance.

A description will be given of a case in which a pole erection work is performed using the digging pole trolley 1 provided with the overwinding prevention device 35 having such a configuration. When performing this work, first, the digging pillar car 1 is stopped at a predetermined pillar working position as shown in FIG. 1, the outrigger 9 is extended downward, and the vehicle body 3 is lifted and supported. Subsequently, the operator operates the operating device 14 to move the boom 13 up and down, turn, and expand and contract, excavate a pole hole using the earth auger device 16, and use a crane mechanism to switch the power pole. For hanging poles and inserting them into pole holes.

In this construction work, for example, a tow wire (not shown) hung on a scaffold bolt attached to a utility pole is lifted by a hook 27 to lift the utility pole, and the boom 13 is operated to remove the suspended utility pole. The electric pole is dropped into the pole hole by moving the wire 25 from the winch device 19 to the pole hole. When performing such a construction work, the hanging rope 31 of the overwinding prevention device 35 may be caught on the scaffolding bolt of the utility pole, and the worker does not notice this and may drop the utility pole as it is. When this is done, a large pulling force acts on the weight suspension rope 31.

Here, the metal ring 51 connecting the weight suspension rope 31 to the switch arm 30 a in the overwinding prevention device 35 is not deformed by a small external force such as the weight of the weight 33, but is not less than a certain value. It is made to be deformed and stretched by a large external force. For this reason, as described above, when the construction work is performed while the weight suspension rope 31 is hooked on the scaffold bolts of the utility pole and a large tension is applied to the weight suspension rope 31, the large tension is applied to the metal. It acts on the ring 51 to deform it and extend it, and the weight suspension rope 31 is separated. As a result, it is possible to reliably prevent a large external force from acting on the switch arm 30a of the overwind detector 30, and to prevent the overwind detector 30 from being damaged.

Next, a second embodiment of the overwinding prevention device will be described with reference to FIG. In the first embodiment described above, the metal ring 51 is used as the connection means. However, in the second embodiment and a third embodiment described later, only the configuration of the connection means is different from that of the first embodiment. Only the configuration of the connection means will be described.

The connection means in the second embodiment is composed of a first locking member 53 and a second locking member 55. The first locking member 53 has spherical tip portions 53a (members to be gripped) protruding from both left and right ends of the body portion. The first locking member 55 has a concave gripping portion 55a for gripping the spherical tip 53a of the protruding member 53, and constitutes a U-shaped elastic support arm as a whole. The body of the first locking member 53 is inserted into the locking hole 39 b of the tongue piece 39 a of the mounting member 39 and is connected to the mounting member 39. The second locking member 55 has a tongue piece 55b at the lower end, to which the locking ring 31c of the weight suspension rope 31 is connected.

As shown in FIG. 4, in a state where the first locking member 53 (the gripped member) is gripped by the second locking member 55 (the elastic supporting arm), for example, as described above, If the pillar suspension work is performed while the weight suspension rope 31 is hooked on the bolt and a large pulling force acts on the weight suspension rope 31, the second locking is performed by the reaction force between the spherical tip 53 a and the grip portion 55 a. The elastic support arm forming the member 55 is extended outward. As a result, the gripping of the first locking member 53 by the elastic force of the elastic support arm is released, the first locking member 31a and the second locking member 31b are separated, and the weight hanging rope 31 together with the weight 33 becomes excessive. It is separated from the winding detector 30. As a result, it is possible to reliably prevent a large external force from acting on the switch arm 30a of the overwind detector 30, and to prevent damage to the overwind detector 30.

Next, a configuration of a connection unit according to a third embodiment will be described with reference to FIG. This connecting means is composed of a first locking member 57 connected to the tongue piece 39a of the mounting member 39 and a second locking member 58 connected to the weight suspension rope 31. The first locking member 57 has a permanent magnet, and a first magnet protrusion 57 a projecting upward is connected to the tongue piece 39 a of the mounting member 39. This connection is made by inserting the first magnet locking hole 57c formed in the first magnet protruding portion 57a into the locking hole 39b of the tongue piece portion 39a. A cutout 57b is provided in 57a. On the other hand, the second locking member 58 is made of a permanent magnet or a magnetic material that is attracted to the permanent magnet that constitutes the first locking member 57, and can be attracted and connected to the first locking member 57 as shown. The second locking member 58 has a second magnet projecting portion 58a projecting downward, and the second magnet engaging hole 58b formed in the second magnet projecting portion 58a is inserted into and connected to the engaging ring 31c of the hanging rope 31. Let me. One of the first locking member 57 and the second locking member 58 may be a permanent magnet, and the other may be a permanent magnet or a magnetic material that is attracted and connected to the magnet.

In the state in which the first locking member 57 and the second locking member 59 are magnetically attracted and connected to each other, for example, as described above, the weight hanging rope 31 is hooked on the scaffold bolt of the utility pole. When a large pulling force acts on the weight suspension rope 31 during the construction of the pillar, the suction connection is released, the second locking member 58 is separated from the first locking member 57, and the weight 33 At the same time, the weight suspension rope 31 is separated from the overwind detector 30. As a result, it is possible to reliably prevent a large external force from acting on the switch arm 30a of the overwind detector 30, and to prevent the overwind detector 30 from being damaged.

In the overwinding prevention device described above, the attachment member 39 and the weight suspension rope 31 are connected by the connection means including the metal ring 51 and the like. However, the present invention is not limited to this, and the connecting means may be provided between the weight hanging rope and the weight, or may be provided in the middle of the weight hanging rope. Further, the attachment member 39 may not be provided.

[0027]

[Effect of the invention]

 As described above, according to the present invention, the weight is attached to the lower end of the weight hanging means (weight hanging rope) that is downwardly hung from the overwind detector attached near the tip of the boom. If the weight is lifted by the tip of the wire or the hook just before the winding state, the overwind detector detects the tension applied from the weight via the weight hanging means, and whether the state is just before the overwind. In the overwinding prevention device configured to detect the overwinding, when the weight suspension means receives an external force exceeding a certain level, the weight side portion is separated from the overwind detector side portion by the connection means. . For this reason, using a crane mechanism having an overwinding prevention device having such a configuration, for example, when a pole is being worked, the weight suspension means (weight suspension rope) is caught on a scaffold bolt of a utility pole. When the weight suspension rope is pulled, the connecting means functions to separate the weight side part from the overwind detector side part. As a result, an external force exceeding a certain level does not act on the overwinding detector, and damage to the overwinding detector can be prevented.

The connecting means may be constituted by a metal ring made of a spirally wound wire, may be constituted by an elastic arm and a member to be grasped elastically by this, or may be constituted by a member to be magnetically attracted and connected. Or you can. Regardless of the configuration, if a large external force (tension) is applied to the weight suspension rope, the connecting means separates, preventing a large external force from acting on the overwind detector and damaging the overwind detector. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view of a digging pole truck equipped with a crane mechanism overwind prevention device according to the present invention.

FIG. 2 is a side view and a partial cross-sectional view near the tip of a boom of the digging and construction pole truck.

FIG. 3 is an enlarged perspective view showing a part of the overwinding prevention device.

FIG. 4 is a front view showing a connection means of the overwinding prevention device of the crane mechanism according to the second embodiment of the present invention.

FIG. 5 is a front view showing a connecting means of the overwinding prevention device of the crane mechanism according to the third embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 13 boom 19 winch device (winch mechanism) 25 wire 27 hook 30 overwind detector 30a switch arm 31 weight hanging rope (weight hanging means) 33 weight 51 metal ring (connection means) 53 first locking member (gripped member) 55 55 second locking member (elastic support arm) 57 first locking member 58 second locking member

Claims (4)

[Utility model registration claims] A boom; a winch mechanism attached to the boom for winding and unwinding a wire; a wire wound around the winch mechanism and unreeled from the winch mechanism and hung from the tip of the boom. An overwinding prevention device for a crane mechanism comprising: a hook attached to the other end of the wire; an overwinding detector attached near a tip of the boom; A weight suspending means that is suspended to the lower end of the weight suspending means, and a weight positioned in the vicinity of the wire so as to be lifted by the distal end portion or the hook immediately before becoming overwound. The overwinding detector detects a tension acting from the weight via the weight suspending means to determine whether the overwinding state has occurred. The weight suspension means has connection means having a function of separating the weight-side portion from the overwinding detector-side portion when subjected to an external force of not less than a certain value. A crane mechanism for preventing overwinding. 2. The connecting means comprises a metal ring formed by spirally winding a wire, and a portion on the overwind detector side and a portion on the weight side are connected via the metal ring. When the weight-side portion is pulled with the external force equal to or more than the predetermined value, the spiral shape of the metal ring is elongated, and the weight-side portion is separated from the overwinding detector-side portion. The overwinding prevention device for a crane mechanism according to claim 1, wherein: 3. The first connection member includes a first locking member connected to a portion on the overwind detector side and a second locking member connected to a portion on the weight side. One of a stop member and the second locking member has an elastic support arm,
The other has a member to be gripped by the elastic support arm, and the second locking member is fixed to the first locking member with the elastic support arm gripping the member to be gripped. 2. The device according to claim 1, wherein when the first holding member is pulled by an external force, the holding of the holding member by the elastic support arm is released, and the first locking member and the second locking member are separated from each other. An overwinding prevention device for the crane mechanism described in the above. 4. The first connection member comprises a first locking member connected to a portion on the overwind detector side and a second locking member connected to a portion on the weight side. The stop member and the second locking member are configured to be suction-connected using magnetic force, and the first locking is performed in a state where the first locking member and the second locking member are suction-connected. The second
When the locking member is pulled by the external force equal to or more than the predetermined value, the suction connection between the first locking member and the second locking member is released, and the first locking member and the second locking member are separated. The overwinding prevention device for a crane mechanism according to claim 1, wherein the device is configured as follows.