JPH08188382A - Locking device of connecting pin of auxiliary jib and the like to top boom - Google Patents

Abstract

PURPOSE: To secure the safety of work by connecting a rotary bracket to which an auxiliary jib or the like is installed, to a top boom securely, in a working vehicle such as a moving type crane. CONSTITUTION: A locking device fixes a bracket 3 to hold a lock plate 1 rotatable, to a rotary bracket 14 to which an auxiliary jib and the like are installed, and it can be positioned stably either to the lock position or the opened position of the lock plate 1 by a spring 2, and at the same time, it is made in a manual type lock whose position can be selected manually by an operator by adding a force more than a specific force. Furthermore, when necessary, the locking device can be used as an automatic lock which is converted to the rotating movement of a lever 4 by a cam 5 by utilizing the movement to move the auxiliary jib and the like from a storing condition to a side holding position, and its movement is transmitted to the lock plate 1 through a connecting member 6, and restores to the locking condition by the spring 2 when the cam 5 is removed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a locking device for mounting pins such as auxiliary jib to a main boom of a work vehicle such as a mobile crane.

[0002]

2. Description of the Related Art As a conventional technique, Japanese Patent Laid-Open No. 6-9191
Referring to Japanese Patent Publication No. 6-52734 and the like, after rotating the rotary bracket to which the auxiliary jib is attached,
In order to prevent the connecting pin from coming off due to malfunction such as oil leakage or backflow of the hydraulic cylinder after the connecting pin is inserted into the pin hole by the connecting device using the hydraulic cylinder, FIGS. As shown in, the operator manually fixed the connecting pin securely with the pin. Figure 10
10A is a side view for explaining fixing the connecting pin with a pin in a state where the hydraulic cylinder is contracted in the conventional locking device and FIG. 10B is a state in which the hydraulic cylinder is expanded. In the drawing, reference characters a are cylinders, b is a connecting pin, c is a pin, d is a pin hole, e is a boom, and f is a rotating bracket.

[0003]

However, in the above-mentioned conventional fixing method, it is difficult to insert the pin due to the deviation of the pin hole,
There was a risk that the pins would be lost, in addition to the need to use two pins at the top and bottom.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a locking device fixes a bracket for holding a lock plate rotatably to a rotary bracket having a supplementary jib or the like and uses a spring. It is a manual lock that can be stably positioned at either the lock position or the open position of the lock plate, and that the operator can manually select the position by applying a specific force or more. Further, if necessary, the locking device uses the movement of moving the auxiliary jib or the like from the stored state to the sideways holding position, and converts it into the rotational movement of the lever by the cam, and transmits it to the lock plate via the connecting member. You can also use an automatic lock that releases the lock and returns to the locked state by a spring when the cam is released.

[0005]

With the above structure, when the lock hydraulic cylinder is positioned at the lock position when the lock hydraulic cylinder is extended,
The lock hydraulic cylinder cannot be reduced, and even if the lock hydraulic cylinder malfunctions, the connecting pin does not come off and safety is maintained. Further, when the lock hydraulic cylinder is contracted, even if the lock hydraulic cylinder is operated to the lock position, only the outside of the hydraulic cylinder is held down, and the lock state is not established, so there is no risk of damage. Furthermore, there is no danger that the pin will be difficult to insert, that it will have to be stopped with two upper and lower pins, or that the pin will be lost.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. For a description of the operation sequence of projecting the supplementary jib 15 and connecting it to the top boom 13, see Japanese Patent Application No. 6-5273.
Since it is described in more detail in No. 4, the description will be omitted, and the components such as the connecting pin 9 and the lock plate 1 of the lock device, which are the main parts of the present invention, will be described. FIG. 1 shows a manual lock. FIG. 2A is a plan view showing a locked state, and FIG. 2B is a side view. 3A is a plan view showing a state in which the lock is opened, and FIG. 3B is a side view. In FIG. 4, the auxiliary jib 15 is extended and the rotation bracket 14 is attached.
Shows the arrangement position Q of the manual lock on the side that is rotated to connect with the top boom 13, and FIG. 5 is an explanatory diagram in which the operator manually operates from the unlocked state to the locked state. FIG. 6 shows the auxiliary jib 15 with the base boom 11
The layout position P of the automatic lock is shown in a plan view in the horizontal holding state in FIG. 7, and FIG. 7 is an explanatory view of the lock relationship at that time. FIG. 8 and FIG. 9 are substantial views of a lock showing a specific arrangement, and are a side view and a plan view, respectively. 11 and 12 are an overall side view and an overall plan view of a mobile crane, respectively.

FIGS. 1 to 5 relate to a manual lock, and the arrangement position is shown as Q in the plan view of the auxiliary jib 15 of FIG. 4 which is extended, but the lock plate 1 can be rotated. Also, the bracket 3 that holds the lock plate 1 so as to cover the rod 8 of the cylinder when the lock hydraulic cylinder 7 is in the extended state is fixed to the rotating bracket 14 that holds the auxiliary jib 15, and the lock plate 1 is locked by the spring 2. It is a manual lock that can be stably positioned at either one of the position and the open position, and that the operator can manually select the position by applying a specific force or more.

On the other hand, with regard to the automatic locks shown in FIGS. 6 and 7, when the auxiliary jib 15 is moved from the retracted state to the horizontal holding position and the connecting pin 9 at the lock position P of the rotary bracket 14 coincides with the top boom 13. , Automatic locking lever 4 mounted on the rotating bracket 14 side
And the cam 5 fixed to the base boom 11 are in an operating relationship, and the lock plate 1 is held open in the opening direction by the movement of the lever 4 transmitted through the connecting member 6. A wire or a rod is used as the connecting member 6. After extending the lock hydraulic cylinder 7 and inserting the connecting pin 9 into the pin hole 10, the second boom 1
By extending 2, the positional relationship between the lever 4 and the cam 5 is released, and the rod 8 of the lock hydraulic cylinder 7 is covered with the lock plate 1 to be in a locked state.

In terms of the function, when the lock hydraulic cylinder 7 is extended and the lock plate 1 is positioned at the lock position, the lock plate 1 is fitted so as to cover the rod 8 of the lock hydraulic cylinder 7, and the lock hydraulic cylinder 7 is locked. Even if a malfunction of the hydraulic circuit occurs, the rod 8 of the lock hydraulic cylinder 7 cannot be contracted, so that the connecting pin does not come off and work safety is ensured. Further, when the lock hydraulic cylinder is contracted, even if the lock hydraulic cylinder is operated to the lock position, only the outside of the hydraulic cylinder is held down, and the lock state is not established, so that there is no fear of damage. Although the lock device for the auxiliary jib of the mobile crane has been described in the above embodiments, it goes without saying that the lock device can be applied to the lock device of the same working machine.

[0010]

As described above in detail, the present invention prevents the lock hydraulic cylinder from contracting when the lock plate is positioned at the lock position when the lock hydraulic cylinder is extended. Therefore, even if the lock hydraulic cylinder malfunctions. The connecting pin does not come off, ensuring work safety. Further, since it is difficult to insert the pin, there is no need to stop the pin with two upper and lower positions, and there is no risk of losing the pin, fatigue factors of the operator are suppressed, which contributes to improvement of work efficiency.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a manual lock.

FIG. 2A is a plan view showing a locked state.
(B) is a side view showing a locked state.

FIG. 3A is a plan view showing a state in which a lock is released. (B) is a side view showing a state in which a lock is opened.

FIG. 4 is a plan view showing the position Q of the manual lock on the side where the auxiliary jib is extended and the rotary bracket is rotated to connect with the top boom.

FIG. 5 is an explanatory diagram in which an operator manually operates the locked state from the unlocked state.

FIG. 6 is an explanatory view showing a position P of the automatic die lock in a plan view in which the auxiliary jib 15 is horizontally held by the base boom 11.

FIG. 7 is a diagram for explaining the relationship between automatic locks.

FIG. 8 is a side view showing a specific lock arrangement.

9 is a plan view of FIG. 8. FIG.

FIG. 10A is a side view showing a state when the hydraulic cylinder is contracted in the conventional lock device. (B) is a side view for explaining fixing the connecting pin with the pin in a state where the hydraulic cylinder is extended.

FIG. 11 is a side view of a work vehicle such as a mobile crane.

FIG. 12 is a plan view of a work vehicle such as a mobile crane.

[Explanation of symbols]

 1 Lock Plate 2 Spring 3 Bracket 4 Lever 5 Cam 6 Connecting Member (Wire or Rod) 7 Lock Hydraulic Cylinder 8 Rod 9 Connecting Pin 11 Base Boom 13 Top Boom 14 Rotating Bracket 15 Supplementary Jib

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsutomu Abe 1-9 Minamidai, Kawagoe City, Saitama Prefecture Komatsu Mec Co., Ltd. Head Office Factory

Claims (2)

[Claims] 1. A bracket for rotatably holding a lock plate (1) with respect to a rod (8) of a lock cylinder (7) in a lock device for a connecting pin (9) of an auxiliary jib (15) to a top boom (13) of a work vehicle such as a mobile crane. 3 is fixed to the rotary bracket 14, and the structure in which the spring 2 can position the lock plate 1 at either the locked position or the open position, and the operator manually selects a position change by applying a specific force or more. A locking device for connecting pins such as auxiliary jib to the top boom, which is equipped with a manually operable lock. 2. The movement of moving the auxiliary jib 15 from the retracted state to the side-holding position on the side surface of the base boom 11,
The cam 5 converts it into a rotational movement of the lever 4, and the connecting member 6 transmits it to the lock plate 1 to release the lock,
The locking device for a connecting pin such as a supplementary jib for a top boom according to claim 1, further comprising an automatic lock having a structure in which the cam (5) is locked by a spring (2) when the cam (5) is disengaged.