JPH0130474Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is a device in which a rod-shaped jib is telescopically inserted into the boom tube at the end of a telescoping boom that can be lifted up and down, and the jib can be locked in the extended position. The present invention relates to a jib restraint device for a retractable boom in an on-vehicle crane, which is provided between the tip boom cylinder and the jib.

(Prior Art) Conventionally, as such a device, a device described in Japanese Utility Model Application No. 120590/1987 is known, but it includes a stopper on the proximal boom cylinder side, which the proximal end of the retracted jib comes into contact with;
In addition to the stopper on the end boom cylinder side that can be freely engaged and detached from the tip of the jib, there is a base on the jib in order to ensure safety in the event that the restraint of the jib by these two stoppers is released due to shaking or vibration when traveling on the road. Requires a removable jib restraining pin that secures the end to the proximal boom tube. This increases the extension length of telescopic booms and jibs, whose length when retracted is restricted by the vehicle length limit when driving on the road, so the length of the pulley support at the tip of the boom tube can be increased. If the length of the retracted jib is kept within the length range of the tip boom tube, the pulley attachment part at the tip of the retracted jib will not be able to be pinned to the pulley support part of the tip boom tube. be.

(Problem to be solved by the invention) In this conventional technology, when the jib is extended or retracted, the worker must move back and forth between the tip and base of the telescopic boom to insert and remove the jib restraint pin. but,
To do this, we need to climb up and down the crane base.
It's really troublesome. In addition, in the case of an on-vehicle crane where the telescoping boom consists of three or more boom cylinders that are fitted in series in a telescopic manner, and at least one boom telescoping cylinder is loosely fitted in the jib, the retracted jib becomes the boom telescoping cylinder. The stopper that the base end of the jib engages with cannot be attached to the base end of the proximal boom tube, and the base end of the jib cannot be pinned to the base boom tube. It disappears.

(Means for Solving the Problem) The present invention addresses this problem, and the present invention is designed to deal with this problem by attaching the tip or intermediate boom of the telescopic boom so that the base end of the jib comes into contact with the retracted telescopic boom when the jib is retracted. A stopper attached to the base end of the tube, a locking device attached to the base end of the boom tube on the side where the stopper is attached so as not to hinder the expansion and contraction of the telescopic boom and the jib, and a stopper attached to the base end of the jib and attached to the jib. A temporary locking device comprising a hook constantly spring-loaded to overcome and engage the locking device during the retracting movement of the jib is provided to restrain the jib in the retracted position with respect to the telescopic boom during retracting. , the hook is interlocked and connected to an operating lever attached to the tip of the jib so that the temporary locking device can be released.

(Function) Since the present invention has the above-mentioned configuration, when extending the retracted jib, the telescopic boom in the retracted state is tilted downward from the horizontal position, and the work is carried out around the tip side of the retractable boom. After confirming that extending the jib will not pose a safety problem, the operator operates the operating lever to disengage the hook from the latch, and the jib is extended to the extended position by the action of its own gravity. From there, the jib can be locked to the tip boom tube.

In addition, when retracting the jib in the extended position, the telescopic boom in the retracted state is tilted slightly downward from the horizontal position, and the jib is unlocked from the tip boom tube, and the jib is inserted into the tip boom tube by the worker. If the jib is pushed in by the operator or the telescopic boom is tilted slightly above the horizontal position and the jib is pushed into the tip boom cylinder by its own gravity, the hook automatically overcomes the locking device and engages with it. At times, the base end of the jib engages with the stopper at the base end of the boom tube, so the stopper prevents the jib from being pushed into the boom tube, and prevents the jib from protruding from the boom tube or from engaging the hook with the locking tool. to restrain the jib in the retracted position.

In this jib restrained state, the proximal ends of adjacent boom tubes and jibs engage with each other in a substantially sliding manner via sliding guides and rollers, and the hook pivoted at the jib proximal end is stopped. Since the locking device on the boom tube on the mounting side is always engaged, the hook may come off from the locking device due to vertical vibration or oscillation when the on-vehicle crane is running, or sudden stops or sudden starts while moving. This can prevent the fixation of the axial position of the jib from loosening due to inertial action accompanying this.

(Example) The figure shows a boom telescopic cylinder 4 that extends and contracts an intermediate boom cylinder 2 with respect to a base end boom cylinder 1, and a boom extension cylinder 4 that extends and contracts an intermediate boom cylinder 2 with respect to the base end boom cylinder 1, and
This is an embodiment of the present invention applied to a telescopic boom including a wrap-around transmission device that extends and retracts the tip boom tube 3 by the same length as the intermediate boom tube.

A wrap transmission device tensions cables 6 passing through pulleys 5 attached to both sides of the distal end of the intermediate boom tube 2 between the upper surface of the top plate of the distal end of the proximal boom tube 1 and the proximal side surface of the distal boom tube 3. The cables 8 are installed and run through pulleys 7 attached to both sides of the base end of the intermediate boom cylinder 2, respectively.
The boom is extended between the lower surface of the top plate of the tip end of the base boom tube 1 and the base top plate of the tip boom tube 3, and the tip of the piston rod is pivoted 9 within the base end of the base boom tube 1. The piston rod insertion side end of the cylinder 4 is pivotally mounted 10 within the base end of the intermediate boom cylinder 2, similar to the invention described in Japanese Utility Model Publication No. 48-28220.

A jib 11 made of a cylindrical body with a rectangular cross section is inserted into the tip boom tube 3 so as to be lightly slidable, with the boom telescopic cylinder 4 loosely fitted therein. That is, a roller 12 (FIG. 2) to be rolled on the bottom plate of the tip boom tube 3 is attached to the lower base end of the jib 11, and the jib 11 is attached to the pulley support portion 3a at the tip of the tip boom tube.
At the same time, a sliding guide 14 (Fig. 6) is installed on the base end side of the jib to slide on the top plate of the tip boom tube 3, and a slide guide 14 (Fig. 6) slides on the side plates of the tip boom tube. Sliding guides 16 and 16' are attached to the slide guide 15 and slidably contact both sides of the jib 11 on the pulley support 3a (FIG. 5).
Install.

Jib 1 for retracted telescopic boom 1, 2, 3
1, the stopper 17 that the support frame of the roller 12 provided at the base end of the jib comes into contact with, and the horizontal beam-shaped locking tool 18 are located inside the base end of the intermediate boom tube 2, as shown in FIG. is fixed to. A pivot 19 (fourth
The hook 20 shown in FIG. 22 is connected to the upper end of the operating lever 23 via a cable 24.

The connecting rod 21 slidably passes through a bracket 25 fixed upright on the jib between the slide guides 14, 14 on both sides, but the rotation range of the hook 20 is limited to the fourth
so as to be limited between the engagement position with the locking tool 18 shown in the figure and the position disengaging upward from the locking tool.
The free end 21a of the connecting rod is formed into a large diameter portion that engages with the bracket 25, and a compression spring 26 is provided between the bracket and a collar provided in the middle of the connecting rod 21.
The hook 20 is always urged to return to the position shown in FIG. 4 by the spring 26.

Therefore, if the extended jib is pushed into the retracted telescopic boom, the sloped end portion 20b of the hook 20
over the locking device and automatically engages with the locking device 18 as shown by the chain line in FIG. 4, and cooperates with the stopper 17 to restrain the jib 11 in the retracted position shown in FIG.

The device for locking the jib in the extended position is such that engaging pieces 27 that respectively engage the lower sliding guides 16 and 16' attached to the pulley support 3a of the tip boom cylinder are fixed and protrude from the side surface of the jib in the extended position. The pin 28 is inserted into a pin hole bored correspondingly to the pulley support part 3a and the jib 11 in the extended position.
6', most of the impact is absorbed by the pulley support part 3a.
It is preferable to catch it with a stopper 29 (Fig. 7) welded to.

In the figure, 30 is a cargo handling pulley attached to the pulley support part 11a at the tip of the jib, 31 is a handle for operating the jib on both sides attached to the lower part of the tip of the pulley support part 11a, 32,
Reference numeral 33 indicates upper and lower cargo handling pulleys attached to the pulley support portion 3a of the tip boom tube, 34 indicates the main winding cable that passes through the pulleys 32 and 33, and 35 refers to the base end of the proximal boom tube 1 that is pivoted to the crane swivel base 36. The supporting foot pin 37 indicates a derrick cylinder that lifts up the base end boom cylinder 1.

Although one embodiment has been described above, if the length of the jib can be shortened, the stopper 17 or the locking tool 18
It is clear that it is also possible to mount it in the proximal end of the tip boom tube 3. Also, although the illustrated telescopic boom has one intermediate boom tube, the intermediate boom tube can be made into two boom tubes that fit telescopically, or each boom tube can be inserted between adjacent boom tubes of the telescopic boom. It is clear that a telescopic cylinder can also be installed.

(Effect of idea) The present invention has the following effects.

(1) When extending the jib from a retractable boom that is tilted downward, it is sufficient to disengage the hook from the locking device using the control lever at the tip of the jib, and when retracting the jib of the retractable boom, , the jib can be pushed into the tip boom cylinder using the handle 31, and the hook can be automatically engaged with the locking tool. Therefore, unlike the conventional method, when the jib is extended or retracted, the jib restraining pin is inserted or removed, and the operator does not have to do it. There is no need for the retractable boom to move back and forth between the tip and base of the retractable boom.

(2) A temporary locking device for restraining the jib in the retracted position is attached to the base end of the boom tube at the intermediate or tip end, which can only substantially slide relative to the proximal boom tube, and to the base of the jib, which can only substantially slide. Since the hook is always urged to engage with the locking tool by a spring, the temporary locking device cannot be accidentally released due to shaking or vibration when the on-vehicle crane is traveling. This prevents it from being bent or loosened.

(3) It can also be applied when a temporary locking device cannot be provided at the proximal end of the proximal boom cylinder, such as when the boom is a multi-stage telescopic boom or the jib length is short.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal side view of an embodiment of the present invention, Fig. 2 is a longitudinal side view of the main parts of the jib when it is extended, Fig. 3 is a perspective view of the tip of the jib, and Fig. 4 is a detail of the hook attachment part. Figures 5, 6, and 7 are respectively
They are an XX cross-sectional view, a Y-Y cross-sectional view, and a Z-Z cross-sectional view of the figure. 1... Proximal boom tube, 2... Intermediate boom tube, 3
... Tip boom cylinder, 4 ... Boom telescopic cylinder,
11... Jib, 17... Stopper, 18... Locking tool, 20... Hook, 23... Operating lever, 24
... Cable, 25 ... Bracket, 26 ... Compression spring.

Claims (1)

[Scope of utility model registration request] In an on-vehicle crane, a rod-shaped jib is telescopically inserted into the tip boom tube of a telescoping boom that can be tilted up and down, and a device capable of locking the jib in the extended position is provided between the tip boom tube and the jib. A stopper attached to the tip of the telescopic boom or the base end of the intermediate boom tube, and a stopper installed in the base end of the boom tube on the side to which the stopper is attached, so that the base end of the jib comes into contact with the telescopic boom when the jib is retracted. A locking device is mounted so as not to impede the telescopic boom and the jib from extending and retracting, and the locking device is pivoted at the proximal end of the jib and is constantly biased by a spring so as to overcome and engage the locking device during retraction movement of the jib. A temporary locking device consisting of a hook is provided to restrain the jib in the retracted position with respect to the telescopic boom when retracted, and the temporary locking device can be released by using the operating lever attached to the tip of the jib. A jib restraint device for a retractable boom characterized by interlocking connection.