JP2527632Y2 - Forklift work equipment lifting prevention device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work machine lift prevention device for a forklift used when a work machine such as a backhoe or an aerial work platform is mounted on the forklift.

[0002]

2. Description of the Related Art Conventionally, in a factory or the like, a backhoe or an aerial work platform may be required separately from daily work. For example, there is a case where it is desired to dig a trench with a backhoe due to a change in the layout of a factory, or a case where it is desired to use an aerial work platform for replacing a lamp of a lighting fixture on a ceiling.

However, since these operations are infrequent, preparing a dedicated working vehicle having a backhoe or an aerial work platform is not only uneconomical but also requires a storage space. Occurs.

[0004] Therefore, the present applicant has proposed a system in which a forklift is used anywhere in a factory or a logistics site, and a backhoe, an aerial work platform and the like are exchangeably installed on a mast lifting frame.

[0005]

In the work by the backhoe, a large reaction force acts on the bucket from the ground surface during excavation, and the reaction force causes a lifting force to act on the lifting frame to which the backhoe is attached. Generally, a single-acting cylinder is used as a lifting cylinder installed on a mast of a forklift, and a lifting frame on which a working machine such as a fork is mounted is lowered by its own weight.

Since a single-acting cylinder is used as described above, if a large lifting force acts on the lifting frame as described above, there is a problem that the lifting frame is lifted. Since the lifting force acting on the lifting frame acts as a moment with a radius centered on the bucket, the lifting range of the lifting frame is limited, but such lifting of the lifting frame makes it difficult to work with the backhoe. There is a point. In addition,
Even when an aerial work platform or the like is used as a working machine attached to the elevating frame, there is a problem in that the aerial work platform is not restrained in the floating direction with respect to the mast, so that the stability is poor.

An object of the present invention is to provide a work machine lift prevention device for a forklift having a simple structure capable of preventing the work machine from lifting and performing a stable operation.

[0008]

SUMMARY OF THE INVENTION A work implement lifting prevention device according to the present invention is provided on a lift frame mounted on a mast of a forklift and driven up and down, or a work machine attached to the lift frame to raise the lift frame. In addition, a lifting prevention piece is provided which engages with a predetermined portion of the mast.

[0009]

According to this structure, by lifting the lifting frame, the lifting prevention piece engages with a predetermined portion of the mast, for example, the lower end, and further lifting is prevented. In this way, the work can be performed in a state where the lifting of the lifting frame is restrained, and the work can be performed stably.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. First, a brief description will be given. This work implement lifting prevention device is provided with a lower end 2 of a mast 2 of a forklift 1.
The L-shaped floating prevention piece 3 engaging with a is attached to a backhoe 17 attached to the lifting frame 14 of the mast 2.

The forklift 1 has wheels 4 and a cab 5
The mast 2 is installed on a frame 7 of a vehicle body 6 provided with The mast 2 is connected to a bracket 10 of the frame 7 via a reversing type mast tilt cylinder 9, and the tilt angle can be adjusted by driving the mast tilt cylinder 9.

The mast 2 is a two-stage mast in which an elevating mast 12 is installed inside the mast main body 11 so as to be able to move up and down. The elevating mast 12 is driven up and down by an elevating cylinder 13 installed in the mast main body 11. The lifting cylinder 13 is a single-acting type. The lifting frame 14 is installed on the lifting mast 12 via a guide roller 14 a so as to be able to move up and down, and is suspended by a moving pulley 15 of the lifting mast 12 with a hanging cable 16.
As the elevating cylinder 13 expands and contracts, it moves up and down by twice the height of the expansion and contraction.

The lifting frame 14 is used to replace various working machines such as forks and the like, and in the illustrated example, a backhoe 17 is mounted instead of a fork as a working machine. The backhoe 17 has a bucket 20 attached to a boom 18 via an arm 19, and includes a boom elevating cylinder 21, an arm cylinder 22,
And a bucket cylinder 23. Boom 18
Is horizontally and freely rotatable on a work machine main body 25 via a swivel table 24, and is driven by a boom swivel cylinder 26 provided on the work machine main body 25 to turn forward and reverse. The working machine body 25 is a fork (not shown) attached to the lifting frame 14.
It may be attached to.

The lifting prevention pieces 3 are provided in a pair on the left and right sides of the working machine main body 25, and the upper ends thereof are detachably attached to the working machine main body 25 by connecting members 27 such as pins or bolts. The lifting prevention piece 3 engages with the lower end of the mast main body 11 of the mast 2 in detail.

FIG. 2 shows a hydraulic circuit of the forklift 1 and the backhoe 17. The hydraulic oil discharged from the pump 28 is supplied to the bucket cylinder 23 and the boom swing cylinder 26 via switching valves 29 and 30 each comprising an electromagnetic valve, and is supplied from the switching valve 29 via the switching valves 31 and 32.
The supply is switched to the boom lifting cylinder 21 and the arm cylinder 22. The mast tilt cylinder 9 is provided with the switching valve 2.
The hydraulic pressure is supplied through the switching valves 9 and 31 and the switching valve 33. A return oil drain tank 34 is connected to the switching valve 33.
The hydraulic piping of the forklift 1 and the hydraulic piping of the backhoe 17 are connected by a detachable coupling (not shown). The hydraulic pressure supply to the lifting cylinder 13 in FIG. 1 is performed through a hydraulic path different from that in FIG.

According to this configuration, when the work by the backhoe 17 is performed, the lifting frame 14 is moved by the lifting cylinder 13.
Is slightly raised from the lower end, and the floating prevention piece 3 is engaged with the lower end 2a of the mast 2 as shown in FIG. In this state, the hydraulic system of the mast cylinder 13 is locked or the hydraulic load state is maintained.

As described above, by performing the work of the backhoe 17 with the lifting prevention piece 3 engaged with the mast lower end 2a, even if the ground reaction force acts on the bucket 20 of the backhoe 17 during excavation, The backhoe 17 is prevented from floating along the mast 2 together with the lifting frame 14. Therefore, the excavation work by the backhoe 17 can be stably performed.

Further, since the lifting prevention piece 3 is engaged with the lower end 2a of the mast by using the lifting cylinder 13 which raises the lifting frame 14, a dedicated driving means for lifting prevention is not required, so that it is easy. With a simple configuration, stable lifting can be prevented.

The lifting-prevention piece 3 may be attached to the lifting frame 14, but when it is attached to the backhoe 17 as in this embodiment, when the backhoe 17 is detached from the lifting frame 14, the backhoe 17 is removed. The lifting prevention piece 3 can be used as a stand for placing the apparatus in a standing posture.
In addition, when the working machine is replaced, the lifting prevention piece 3 may be attached and detached together with the backhoe 17, and it is not necessary to attach and detach the lifting prevention piece 3 to and from the lifting frame 14.

In the above-described embodiment, the case where the backhoe 17 is mounted as the working machine of the forklift 1 is described. However, the work machine floating prevention device of the present invention is used when other various working machines are mounted and used. it can.

For example, as shown in FIG. 3, even when an aerial work platform 38 is mounted as a working machine, stable support by the floating prevention piece 3 can be performed. The high work table 38 has a telescopic lifting drive 39 and a guide frame 40, and is detachably mounted on a fork 41 mounted on the lifting frame 14 of the mast 2 by a socket-like base 42. . The lifting prevention piece 3 is attached to a lifting frame 14.

In this configuration, the work platform 38 is fixed integrally with the mast 2 due to the engagement by the lifting prevention pieces 3. For this reason, the work platform 38
Is obtained, and the stability against falling is improved.

In the above embodiment, the lifting prevention piece 3 is engaged with the lower end 2a of the mast 2.
The lifting prevention piece 3 may be engaged with a horizontal rail or the like joining the left and right pillars of the mast 2 at an intermediate height of. Further, in each of the above embodiments, the lifting prevention piece 3 is
And the like, but the lifting prevention piece 3 may be freely changeable in angle or detachable with respect to these working machines or the like. This allows
The lifting frame 1 with the lifting prevention piece 3 not engaged with the mast 2
4 can be raised, and the work machine can be used at a high position of the mast 2.

The work machine lifting prevention device can also be applied to the case where a work machine used while the forklift 1 is traveling, for example, a work machine such as a bucket loader.

[0025]

According to the present invention, the lifting device for a working machine lift is mounted on a mast of a forklift and driven up and down, or a work machine attached to the lifting frame, and the work machine is mounted on the mast of the forklift as the mast is raised. Since the floating preventing piece is provided at a predetermined position, the work machine can be prevented from floating and stable work can be performed. In addition, since the lifting is performed using the driving force for raising the lifting frame, there is no need for a dedicated driving unit for preventing the lifting, and there is an effect that the floating can be stably prevented with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a side view of a forklift equipped with a work implement lifting prevention device according to an embodiment of the present invention.

FIG. 2 is a hydraulic circuit diagram thereof.

FIG. 3 is a side view of an example in which an aerial work platform is attached to the forklift.

[Explanation of symbols]

1: Forklift, 2: Mast, 3: Lifting prevention piece,
4 wheel, 9 mast tilt cylinder, 13 lifting cylinder, 14 lifting frame, 17 backhoe, 38 work platform

Claims (1)

(57) [Scope of request for utility model registration] A lifting frame which is installed on a mast and is driven to move up and down, or a working machine attached to the lifting frame, is provided with a lifting prevention piece which engages with a predetermined portion of the mast as the lifting frame rises. The forklift work equipment lifting prevention device provided.