JPH0581183U - On-board crane arm return mechanism - Google Patents

Abstract

(57) [Summary] [Purpose] Prevents forgetting to store the crane arm when traveling with a small crane mounted on the bed of a truck. [Structure] A shaft portion 21 is attached to a lower end portion of the column 1, and the shaft portion 21 is fixed to the upper surface of the pedestal 6 and is rotated into the pedestal 6 via a stopper 22 having a step portion 22a as shown in FIG. A pin 23 capable of abutting on the step portion 22a of the stopper 22 is planted on the outer peripheral surface of the shaft portion 21 so as to be movably inserted. One end of the spiral spring 25 that is biased in the rotating direction is attached, and the other end of the spiral spring 25 is locked to the pedestal 6.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a vehicle-mounted crane that can be mounted on a loading platform such as a truck, and more particularly to a mechanism for returning an arm to a storage position.

[0002]

[Prior Art]

 For the delivery of electric appliances and the transportation of agricultural products, generally, these products are carried on the bed of a small truck (light truck). However, the present situation is that most of the work of loading and unloading these loads on the truck bed depends on manpower. It is possible to use a crane for the above-mentioned loading and unloading work, but it is not possible to use a large crane that is used at construction sites. Therefore, a small crane that can be mounted on the truck bed is being developed.

In such a small crane, an arm is attached to a support provided on a loading platform, and the support is rotatable so that the arm can swing up and down with respect to the support, or the support is fixed. In order to improve workability, it is necessary to allow the arm to rotate at least as a whole, regardless of whether the arm is rotatable and swingable with respect to the column.

[0004]

[Problems to be solved by the device]

 By the way, in the case where the arm can be turned in this way, there is a possibility that the arm may forget to be stored in the luggage carrier after the work is finished and the arm may travel while protruding outside the vehicle.

[0005]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention provides a return spring for urging the support in a direction of rotating the arm to the retracted position, between the support rotatably supported on the carrier and the fixing member.

[0006]

[Action]

 Since the column is urged by the spring in the direction to rotate the arm to the storage position, the arm automatically returns to the storage position after the work is completed, and it is possible to prevent forgetting to store the arm.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view of a vehicle-mounted crane to which an arm return mechanism according to the present invention is applied, mounted on a light truck, FIG. 2 is an overall view of the vehicle-mounted crane according to the present invention, and FIG. 3 is the arm return mechanism. FIG. 4 is a plan sectional view of the returning mechanism portion.

The vehicle-mounted crane is mainly composed of a support column 1, a crane arm 2, a power unit 3 and a rope 4, the support column 1 is made of a square pipe, and the lower end thereof is detachably mounted on a loading platform S by a bolt 5. A pedestal 6 is rotatably supported about a vertical axis, and an upper end thereof is detachably supported by a bracket 8 provided on a torii 7 standing upright on the front part of the loading platform S by using bolts 9.

The crane arm 2 is swingably supported in a vertical plane via a shaft 11 on a bracket 10 provided on the upper end of the support column 1, and a bracket 12 is provided at the tip thereof, and a pulley 13 is attached to the bracket 12. A rope (including a wire and a chain) 4 fixed to the lower part of the column 1 is hung around a pulley 13 and hung downward, and a hook 14 for hooking a load is attached to the lower end thereof.

Further, the power unit 3 is a motor, a hydraulic pump driven by the motor, a cylinder unit to which hydraulic oil is supplied and discharged from the hydraulic pump, a sub tank for compensating for the piston rod of the cylinder unit, and a hydraulic oil flow path. The valve mechanism for switching between the cylinder unit is rotatable, and the base end of the cylinder unit is freely rotatable to the bracket 16 provided at the middle of the column 1 and the tip of the piston rod is freely rotatable to the bracket 17 provided at the crane arm 2. Connected to.

On the other hand, as shown in FIGS. 3 and 4, a shaft portion 21 is attached to the lower end portion of the column 1, and a step portion 22a is fixed to the upper surface of the pedestal 6 as shown in FIG. A pin 23 that is rotatably inserted into the pedestal 6 through the formed stopper 22 and that can contact the step portion 22a of the stopper 22 is provided on the outer peripheral surface of the shaft portion 21. Further, in the pedestal 6, a spiral spring 25 for urging the crane arm 2 with respect to the support column 1 in a direction to rotate the crane arm 2 to a retracted position (positioned along the torii 7 as shown in FIG. 1) is provided. One end is attached, and the other end of the spiral spring 25 is locked to the pedestal 6.

[0012] In the above, when the luggage is placed on the bed, the operator turns the crane arm 2 to the hanging position, and then drives the power unit 3 to compress the cylinder unit to move the crane arm 2 to the position shown in FIG. 2 to the imaginary line position, hook the hook 14 at the end of the rope 4 on the load, drive the power unit 3 to extend the cylinder unit, and raise the crane arm 2 to the imaginary line position in the figure. Turn it horizontally to the rest position.

In this case, when the crane arm 2 is rotated in the direction away from the storage position, the rotation of the support column 1 accumulates the restoring force in the spiral spring 25. Even if the user forgets to return to the inside of S or the storage position, the support force of the spiral spring 25 causes the column 1 to rotate in the direction of the storage position of the crane arm 2 to return the crane arm 2 to the inside of the loading platform S or the storage position.

At this time, as the spiral spring 25, it is preferable to use one having a restoring force enough to return the crane arm 2 to the retracted position, but any coil spring capable of returning the crane arm 2 to at least the inside of the loading platform S may be used. ..

Further, since the rotation range of the column 1 is regulated by the pin 23 coming into contact with the stopper 22, the crane arm 2 hits the torii 7 when the crane arm 2 returns to the storage position by the restoring force of the spiral spring 25. The contact can be prevented, and the crane arm 2 can be prevented from being rotated so as to impair the restoring force of the spiral spring 25.

[0016]

[Effect of the device]

 As described above, according to the present invention, since the support rotatably supported on the loading platform is provided with the spring for urging the support in the direction to rotate the arm to the storage position, the work is completed. The rear arm automatically returns to the stowed position, preventing you from forgetting to stow the arm.

[Brief description of drawings]

FIG. 1 is a perspective view of a vehicle mounted crane equipped with an arm return mechanism according to the present invention mounted on a light truck.

[Fig. 2] Overall view of an on-vehicle crane according to the present invention

FIG. 3 is a front sectional view of the arm return mechanism section.

FIG. 4 is a plan sectional view of the arm return mechanism section.

FIG. 5 is a perspective view of a stopper of the arm return mechanism section.

[Explanation of symbols]

1 ... Prop, 2 ... Crane arm, 3 ... Power unit,
4 ... Rope, 6 ... Pedestal, 7 ... Torii, 21 ... Shaft, 22 ...
Stoppers, 23 ... Pins, 25 ... Spiral springs.

Claims (1)

[Scope of utility model registration request] 1. A support column rotatably supported on a loading platform of a vehicle about a vertical axis, and a support member pivotably supported by an upper end of the support column in a vertical plane and a lifting member hanging from a tip end thereof. In a vehicle-mounted crane equipped with
An arm returning mechanism for a vehicle-mounted crane, characterized in that a return spring for urging the support column in a direction of rotating the arm to a storage position is provided between the support column and a fixing member attached to the vehicle body.