JP2012153518A - Mobile crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile crane A having the rear end of a swivel base 2 projected backward, so that the total length of a vehicle 1 does not become long even in a travelling state where a telescopic boom 3 is detached from the mobile crane A.SOLUTION: With the telescopic boom 3 detached from the swivel base 2 and the front part of the swivel base 2 directed to the rear end of the vehicle 1, the tip part of a fully-minimized derricking hydraulic cylinder 4 and the rear end part of the vehicle 1 are connected with an auxiliary connection means 29. When the tip part of a wire rope 6 pulled out from a winch 5 is engaged to the tip part of the derricking hydraulic cylinder 4 for fixing the derricking hydraulic cylinder 4, a tension control means 20 for winding in the wire rope 6 by a constant tension from the winch 5 is arranged.

Description

  The present invention relates to a mobile crane.

Conventionally, as shown in FIG. 8, this type of mobile crane A has a swivel base 2 disposed on a vehicle 1 so as to be able to turn, and the base end of the swivel base 2 can be pivotally supported by a pivotal support portion. The telescopic boom 3 is disposed at a proper position, the hoisting hydraulic cylinder 4 is disposed between the telescopic boom 3 and the swivel base 2 to drive the telescopic boom 3 up and down with respect to the swivel base 2, and the pivot portion of the swivel base 2. A hook 7 is suspended from the tip of the telescopic boom 3 by a wire rope 6 fed out from a hydraulically driven winch 5 that protrudes further rearward, and a suspended load is suspended on the hook 7 for crane work. .
By the way, when such a mobile crane A becomes large, its weight and total length will exceed and it will not be able to travel on public roads. Therefore, the telescopic boom 3 is detached and the telescopic boom 3 is moved to the target site with another transport vehicle. The technique of reducing the weight of the mobile crane A and shortening the overall length by carrying it has been known for a long time. (For example, see Patent Document 1)

JP-A-57-160890

  However, in recent years, in the large-sized mobile crane A, the counterweight 8 attached to the rear of the swivel base 2 is attached as far as possible in order to improve its lifting performance. Even in the removed traveling state (a state in which the front portion of the preceding platform 2 is positioned forward), there is a problem that the rear of the turntable protrudes rearward and the total length of the vehicle becomes long.

  Therefore, the present application aims to provide a mobile crane A in which the rear of the turntable protrudes rearward so that the total length of the vehicle does not increase even when the telescopic boom 3 is removed from the mobile crane A. is there.

  The present invention has the following configuration as means for solving the above problems.

[Invention of Claim 1 of the Present Application]
The mobile crane according to the first aspect of the present invention has a swivel arranged on a vehicle so as to be able to turn, a base end portion thereof is pivotally supported on the swivel and a telescopic boom is arranged so that it can be raised and lowered. The hydraulic cylinder for hoisting is arranged between the swivel base and the telescopic boom is driven to move up and down with respect to the swivel base, and is extended from a hydraulically driven winch that protrudes rearward from the pivot part of the swivel base. A mobile crane that hangs a hook from the tip of a telescopic boom with a wire rope that is fully retracted with the telescopic boom detached from the swivel and the front of the swivel directed to the rear of the vehicle. When connecting the leading end of the hydraulic cylinder and the rear end of the vehicle with auxiliary connecting means, and locking the leading hydraulic cylinder by locking the leading end of the wire rope fed from the winch to the leading hydraulic cylinder tip And it is characterized in that a tension control means for entrainment of the wire rope from the winch with a constant tension.

  In the mobile crane according to the first aspect of the present invention, with the telescopic boom detached from the swivel and the front of the swivel directed toward the rear of the vehicle, the front end of the hydraulic cylinder for hoisting and the rear of the vehicle are fully contracted. When the ends are connected by auxiliary connecting means and the tip of the wire rope fed out from the winch is locked to the tip of the hoisting hydraulic cylinder to fix the hoisting hydraulic cylinder, the wire rope is caught from the winch It is characterized by the fact that a tension control means that performs a constant tension is arranged, so that the tip of the hydraulic cylinder for undulation in the fully contracted state protrudes backward of the vehicle, and this protrusion amount is This can be less than when the rear part is directed rearward and the rear part of the swivel is protruded from the rear of the vehicle, and the overall length of the vehicle in the running state can be shortened. In addition, the front end of the hoisting hydraulic cylinder in the fully reduced state and the rear end of the vehicle are connected by auxiliary connecting means, and the front end of the wire rope fed from the winch is locked to the front end of the hoisting hydraulic cylinder. The tension control means can wind the wire rope from the winch with a constant tension and fix the hoisting hydraulic cylinder protruding rearward of the vehicle. Further, since the wire rope from the winch is wound with a constant tension by the tension control means, the auxiliary rope connecting means prevents the wire rope wound around the drum in the winch due to excessive winch winding, and the auxiliary connecting means. It is possible to fix the undulating hydraulic cylinder while preventing damage.

[Invention of claim 2 of the present application]
A mobile crane according to a second aspect of the present invention is the mobile crane according to the first aspect, further comprising: a boom separation detecting means for detecting the separation of the telescopic boom; and a low pressure relief valve for lowering a hydraulic circuit for driving the winch, The tension control means is configured to maintain the tension constant by setting the hydraulic circuit at a low pressure with a low-pressure relief valve when the boom release detecting means detects the release of the telescopic boom.

  The mobile crane according to claim 2 of the present invention is the mobile crane according to claim 1, wherein the boom disengagement detecting means for detecting the disengagement of the telescopic boom and the low pressure relief valve for lowering the hydraulic circuit for driving the winch are disposed, The tension control means is characterized in that when the boom release detecting means detects the release of the telescopic boom, the hydraulic circuit is configured to maintain a constant tension by lowering the pressure with a low pressure relief valve. When the telescopic boom is detached, the boom disengagement detecting means detects the disengagement of the telescopic boom, and the tension control means automatically reduces the hydraulic circuit to a low pressure with a low pressure relief valve to maintain the tension constant. Fix the hydraulic cylinder for undulations by preventing the wire rope wound around the drum in the winch from getting caught and preventing the auxiliary connecting means from being damaged. Rukoto can.

[Effect of the invention of claim 1 of the present application]
In the mobile crane according to claim 1 of the present invention, with the telescopic boom detached from the swivel and the front part of the swivel directed to the rear of the vehicle, the fully retracted hoisting hydraulic cylinder is connected to the hoisting hydraulic cylinder front end. The rear end of the vehicle is connected by auxiliary connecting means, and the tip of the wire rope fed out from the winch is locked to the tip of the hydraulic cylinder for hoisting by the tension control means, and the wire rope from the winch is kept at a certain tension. The undulation hydraulic cylinder is fixed by winding.

  Therefore, the mobile crane of claim 1 of the present application has the following effects.

  (1) The tip of the hoisting hydraulic cylinder in the fully contracted state protrudes toward the rear of the vehicle, and the amount of protrusion is greater than when the rear of the swivel is directed rearward and the rear of the swivel protrudes from the rear of the vehicle. The total length of the vehicle in the running state can be shortened.

  (2) Connect the leading end of the hoisting hydraulic cylinder in the fully reduced state and the rear end of the vehicle with auxiliary connecting means, and lock the leading end of the wire rope fed from the winch to the leading end of the hoisting hydraulic cylinder. The tension control means can wind the wire rope from the winch with a constant tension, and can fix the undulating hydraulic cylinder protruding rearward of the vehicle.

(3) Since the wire rope from the winch is wound with a constant tension by the tension control means, the auxiliary rope is prevented from getting caught by the wire rope wound around the drum in the winch due to excessive winch winding. It is possible to fix the undulating hydraulic cylinder while preventing damage to the means.

[Effect of the invention of claim 2 of the present application]
The invention of claim 2 of the present application is the mobile crane according to claim 1, wherein a boom disengagement detecting means for detecting the disengagement of the telescopic boom and a low pressure relief valve for lowering a hydraulic circuit for driving the winch are arranged. The tension control means is configured to maintain the tension constant by setting the hydraulic circuit to a low pressure with a low-pressure relief valve when the boom separation detecting means detects the separation of the telescopic boom.

  Therefore, in the mobile crane of claim 2, when the telescopic boom is detached from the swivel base, the boom disengagement detecting means detects the disengagement of the telescopic boom, and the tension control means automatically connects the hydraulic circuit with the low pressure relief valve. Since the tension is kept constant at a low pressure, the hoisting hydraulic cylinder can be fixed by preventing the wire rope wound around the drum in the winch from being excessively wound and preventing the auxiliary connecting means from being damaged. it can.

It is a hydraulic circuit diagram employ | adopted as the mobile crane of an Example of this application. It is explanatory drawing explaining the mobile crane of an Example of this application, and is explanatory drawing explaining the state which mounted the counterweight on the vehicle. It is explanatory drawing explaining the mobile crane of an Example of this application, and is explanatory drawing explaining the state which lifts a counterweight with a self crane from the state of FIG. It is explanatory drawing explaining the mobile crane of this-application Example, After mounting a counterweight on another conveyance vehicle from the state of FIG. 3, the state before making an expansion-contraction boom into a retracted state and releasing an expansion-contraction boom is demonstrated. It is explanatory drawing. It is explanatory drawing explaining the mobile crane of an Example of this application, and is an explanatory drawing explaining the state which latched the hydraulic cylinder for raising / lowering with the wire rope from a winch after detaching | releasing an expansion-contraction boom from the state of FIG. It is explanatory drawing explaining the movable crane of this-application Example, The state which orient | assigned the front part of a swivel back to the back from the state of FIG. 5, and connected between the hydraulic cylinder front-end | tip part and the rear-end part of a vehicle with the auxiliary | assistant connection means. It is explanatory drawing explaining these. It is explanatory drawing explaining the mobile crane of an Example of this application, and is explanatory drawing explaining the latching of the hydraulic cylinder tip part for raising / lowering in detail. It is explanatory drawing explaining the conventional mobile crane.

[Example]
The mobile crane of the present invention will be described below with reference to FIGS. In addition, about the code | symbol of the mobile crane A shown and demonstrated in FIG. 8, description is abbreviate | omitted and it uses the same code | symbol also in the following description.

  FIG. 1 is a hydraulic circuit diagram employed in the mobile crane of the present embodiment. In FIG. 1, the pressure oil from the hydraulic pump 10 drives and controls the winch 5 by operating the winch operation valve 11. The winch 5 includes a hydraulic motor 13, a speed reducer 14, and a drum 15. Reference numeral 16 denotes a counter balance valve which is provided in a hoisting oil passage 17 between the winch operation valve 11 and the winch 5 and is opened by a pilot pressure from the lowering oil passage 18, and at the time of hoisting the winch operation valve 11 to the winch 5 There is a check valve that allows the oil to be supplied to and prevents the oil from being supplied in the reverse direction. A relief valve 19 sets the hoisting oil passage 17 to a pressure set to a predetermined high pressure, and is interposed between the hoisting oil passage 17 and the lowering oil passage 18.

  Reference numeral 20 denotes tension control means, which comprises a low-pressure relief valve 21 and a solenoid valve 22. The low pressure relief valve 21 and the solenoid valve 22 are connected in series as shown in FIG. 1 and are connected between the hoisting oil passage 17 and the lowering oil passage 18. Reference numeral 23 denotes a boom attachment / detachment detection means for detecting that the telescopic boom 3 has been detached from the swivel base 2. For example, the base end portion of the telescopic boom 3 is pivoted to the swivel base 2 by a pivot. It consists of a switch (not shown) that operates when it is supported.

The telescopic boom 3 is provided with a length detector that detects the length between the distal end and the base end of the telescopic boom 3 in order to detect the telescopic length, and a detection signal of the length detector. However, when the telescopic boom 3 is detached from the swivel base 2, it is necessary to disconnect the connection between the length detector and the safety device. Therefore, the boom attachment / detachment detection means 23 may detect the disconnection and detect the boom attachment / detachment.

A power supply is connected to the solenoid of the solenoid valve 22 via a boom attachment / detachment detection means 23, and the solenoid valve 22 is in the valve closing position 22a when the boom attachment / detachment detection means 23 does not detect the removal of the telescopic boom 3. When the boom attachment / detachment detection means 23 detects the detachment of the telescopic boom 3, it is switched to the valve opening position 22b.

Hereinafter, the process of detaching the telescopic boom 3 from the working state of the mobile crane according to the present invention and turning it into a traveling state will be described with reference to FIGS. FIG. 2 is an explanatory view for explaining the mobile crane according to the embodiment of the present invention, and is an explanatory view for explaining a state in which the counterweight attached at the rear position of the swivel base 2 is placed on the vehicle. That is, the front portion of the turntable 2 is directed rearward, and the counterweight 8 attached to the rear portion of the turntable 2 is lowered by a hydraulic cylinder (not shown) attached to the turntable 2 or the counterweight 8 side. 1 is placed on the front.

FIG. 3 is an explanatory view for explaining the mobile crane of the embodiment of the present application, and is an explanatory view for explaining a state in which the counterweight 8 is lifted by its own crane from the state of FIG. From the state of FIG. 2, the swivel base 2 is directed forward, and the telescopic boom 3 is raised and lowered while the wire rope 6 is fed from the winch 5 so that the hook 7 is positioned on the counterweight 8. Then, the counterweight 8 is lifted from the hook 7 via a hanging tool and placed on the loading platform of another transport vehicle from the vehicle 1.

  FIG. 4 is an explanatory view for explaining the mobile crane according to the embodiment of the present invention. After the counterweight 8 is placed on another transport vehicle from the state of FIG. 3, the telescopic boom 3 is set in the retracted state and the telescopic boom 3 is detached. It is explanatory drawing explaining the state before performing. After the counterweight 8 on the vehicle 1 is placed on the loading platform of another transport vehicle, the support 24 is attached to the front portion of the vehicle 1. The support base 24 is a support base that supports the hoisting hydraulic cylinder 4 when the telescopic boom is retracted and the telescopic boom is detached. The swivel base 2 is directed forward, the hoisting hydraulic cylinder 4 is reduced, the telescopic boom 3 is laid down, and the telescopic boom is brought into the retracted state. Thereafter, the telescopic boom 3 is detached from the swivel base 2 with a lifting device such as another crane.

  FIG. 5 is an explanatory view for explaining the mobile crane according to the embodiment of the present invention. After the telescopic boom 3 is detached from the state of FIG. 4, the hoisting hydraulic cylinder 4 is locked with the wire rope 6 from the winch 5. It is explanatory drawing explaining these. After the telescopic boom 3 is detached from the swivel base 2 and the hoisting hydraulic cylinder 4 is supported by the support base 24, a bracket 25 shown in FIG. 7 is attached to the tip of the hoisting hydraulic cylinder 4 with a pin 26. Mounting holes 25a and 25b are provided at the upper and lower ends of the bracket 25, respectively. A tip tool 27 to which the tip of the wire rope 6 fed from the drum 15 of the winch 5 is fixed is connected to the mounting hole 25a with a pin. Then, the winch 5 is slightly wound up, and the hydraulic cylinder 4 for undulation is supported by the wire rope 6 and floated from the support base 24.

FIG. 6 is an explanatory view for explaining the mobile crane according to the embodiment of the present invention. The front part of the swivel base is directed rearward from the state of FIG. 5, and the space between the front end part of the hoisting hydraulic cylinder 4 and the rear end part of the vehicle 1 is shown. It is explanatory drawing explaining the state connected with the auxiliary | assistant connection means. In a state where the hoisting hydraulic cylinder 4 is supported by the wire rope 6, the front portion of the swivel base 2 is directed backward. Then, as shown in detail in FIG. 7, auxiliary connecting means 29 is connected between the mounting hole 25b of the bracket 25 and a stopper 28 attached to the rear end of the vehicle. The auxiliary connecting means 29 includes an auxiliary wire rope 29a constituted by a wire rope, a shackle 29b for connecting the auxiliary wire rope 29a and the mounting hole 25b, and a shackle 29c for connecting the auxiliary wire rope 29a and the stopper 28. . The auxiliary wire rope 29a is a wire rope, but may be a chain, a chain, a belt, or the like. Further, although not shown, the mounting hole 25b and the stopper 28 are provided in a pair of left and right, and auxiliary wire ropes 29a are also arranged on the left and right, respectively. By arranging the left and right pairs in this way, the undulation hydraulic cylinder 4 is restricted from swinging left and right during travel.

After the auxiliary connecting means 29 is connected to the bracket 25, the winch operation valve 11 is operated to wind up the winch 5. At this time, since the telescopic boom 3 is detached, the solenoid valve 22 is switched to the open position 22b by the boom attachment / detachment detection means 23, and the hoisting oil passage 17 is set to a low pressure by the low pressure relief valve 21. Yes. Therefore, the wire rope 6 is wound by the winch 5 by the tension control means 20 with a constant tension.

Accordingly, the front end of the hoisting hydraulic cylinder 4 in the fully contracted state and the rear end of the vehicle 1 are connected by the auxiliary connecting means 29, and the front end of the wire rope 6 fed from the winch 5 is connected to the hoisting hydraulic cylinder 4. The undulation hydraulic cylinder 4 protruding rearward of the vehicle 1 can be fixed by winding the wire rope 6 from the winch 5 with a constant tension by the tension control means 20.

Further, since the wire rope 6 from the winch 5 is wound with a constant tension by the tension control means 20, the wire rope 6 wound around the drum 15 in the winch 5 due to excessive winch winding is prevented. In addition, the hydraulic cylinder 4 for undulation can be fixed while preventing the auxiliary connecting means 29 from being damaged.

The swivel base 2 from which the telescopic boom 3 is detached is directed rearward, and the front end portion of the hoisting hydraulic cylinder 4 in the fully contracted state projects rearward of the vehicle 1. It is possible to reduce the total length of the vehicle 1 in the traveling state, as compared with the case where the rear portion of the swivel base 2 protrudes from the rear of the vehicle 1.

  As described above, the process of detaching the telescopic boom 3 from the working state of the mobile crane of the present invention and setting it to the traveling state has been illustrated and described in FIGS. About the process to perform, what is necessary is just to carry out reverse of said, and description is abbreviate | omitted.

  1 is a vehicle, 2 is a swivel, 3 is a telescopic boom, 4 is a hydraulic cylinder for hoisting, 5 is a winch, 6 is a wire rope, 7 is a hook, 20 is a tension control means, 21 is a low pressure relief valve, and 23 is a boom release The detecting means 29 is an auxiliary connecting means.

Claims (2)

A swivel is arranged on the vehicle so as to be able to turn, a base end of the swivel is pivotally supported by a pivot, a telescopic boom is placed so that it can be raised and lowered, and a hydraulic cylinder for hoisting is installed between the telescopic boom and the swivel at a suitable position. The telescopic boom is driven up and down with respect to the swivel, and the hook is hung from the tip of the telescopic boom by a wire rope fed out from a hydraulically driven winch that protrudes rearward from the pivot part of the swivel. A mobile crane to be lowered,
With the telescopic boom detached from the swivel base and the front part of the swivel base directed toward the rear of the vehicle, the front end of the hydraulic cylinder for hoisting in the fully reduced state and the rear end of the vehicle are connected by auxiliary connecting means, A tension control means is installed to hold the wire rope from the winch with a constant tension when the hydraulic cylinder for undulation is fixed by locking the tip of the wire rope fed out from the winch to the tip of the hydraulic cylinder for undulation. A mobile crane characterized by that.   2. The boom disengagement detecting means for detecting the disengagement of the telescopic boom and a low pressure relief valve for lowering a hydraulic circuit for driving the winch are arranged, and the tension control means is configured such that the boom disengagement detecting means is a telescopic boom. The mobile crane is configured to maintain the tension constant by setting the hydraulic circuit at a low pressure with a low-pressure relief valve when the separation of the oil is detected.

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