JPS5917039B2 - Fork lift truck push pull attachment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to push-pull attachments for forklift trucks.

The device shown in FIG. 1 is a typical conventional example of a so-called push-pull attachment 100 for pushing out a load on a fork 1 or pulling a new load onto the fork.

A fork 1 and a pair of guide rails 5 are fixed to a lift bracket 12 that moves up and down along a mast (not shown) of a forklift truck, and both guide rails 5 are connected by a horizontal frame 4 to form an upright frame. .

A pair of pantographs 2 that extend and contract are interposed between this frame and a movable face plate 3.

Each pantograph 2 has links 2a, 2b and 2c, 2d
The link mechanism is composed of one or more link mechanisms which are pivotally connected in an X-shape so that they intersect with each other, and is provided between a link 2a whose upper end is guided by a guide rail 5 and moves up and down, and a horizontal frame 4. It is expanded and contracted by a bush cylinder 6.

On the other hand, on the face plate 3 side, as shown in FIG. 2, a gripper device 7 is provided.

That is, a gripper channel 11 fixed to the lower end of the face plate, a gripper cylinder 8, and a gripper 9 connected to its piston rod 8a are provided, and in the case of a so-called pull operation (pulling a load), the edge of a sheet pallet such as a paper pallet, etc. After gripping the part between the gripper channel 11 and the gripper 9, the bushing cylinder 6 is retracted to retract the pantograph 2, so that the load together with the sheet pallet can be pulled onto the fork 1.

On the other hand, when pushing out a load from above the fork 1, the push cylinder 6 is operated in the extension direction (along with the seat pallet if there is one) to extend the pantograph 2.
Cargo with face plate 3 (including sheet pallet)
Push out.

When the extrusion is completed, the operating direction of the gripper cylinder 8 is reversed, the gripper 9 is raised, the gripper stops gripping the sheet pallet, and the cargo is unloaded together with the sheet pallet.

The above operations are performed by controlling both the bush cylinder 6 as the pantograph drive means and the gripper cylinder 8 as the gripper drive means by respective series of control valves.

Therefore, two control valves and two hand levers were required to operate them.

However, in general, forklift trucks always require two control valves and two hand levers to operate the lift cylinder L and tilt cylinder T, as shown in Figure 3. In addition, forklift trucks with push-pull attachments require four control valves and four...

On the other hand, the present invention has succeeded in making a single cylinder serve as both the pantograph drive means and the gripper drive means, and the above-mentioned valves can also be used in three sets.
Piping can also be reduced accordingly.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In FIG. 4, the lift bracket side has the same structure as the conventional device shown in FIG. 60 in an upright position.

A gripper channel 11 (1) having a U-shaped cross section is fixed to the lower end of the face plate 30 with the opening facing forward, and a longitudinal gripper 90 is attached to the upper flange 110a and the lower flange 1 in the gripper channel 110.
10b.

Inward guide rails 31 and 31 are fixed to the upper portions of both sides of the face plate 300, and rollers 4L 41 (see FIG. 6) guided by these guide rails 31 are rotatably held at both ends, and a pair of links are provided. A horizontal bar 40 is provided to connect the upper ends of 20a.

As shown in FIG. 5, the cylinder 60 is provided with a first small diameter part 60a and a second small diameter part 60b extending downward,
The first small diameter portion 60a slidably passes through the bushing 111 and liner 112 fixed to the upper flange 110a of the gripper channel 110, as shown in FIGS. Part 90a
Insert it into the holder and secure it with a spring pin, etc.

On the lower surface of the gripper 90 and the upper surface of the lower flange 110b, convex or concave engagement strips 90c, 11 that engage with each other are provided.
It is desirable to provide 0c.

A piston rod 61 extendable from the upper end of the cylinder 60 is rotatably connected to the horizontal bar 40 by a joint 62 fixed to the upper end thereof.

Further, as shown in FIG.
0a, respectively, and the lower end of the link 20b is pivoted to a bracket 32 fixed to the gripper channel 111).

A single cylinder 60 configured as above is connected to the lower gripper 9.
0 and the upper crossbar 40, it performs the functions of a bush cylinder and a gripper cylinder.

The situation is as shown in FIGS. 9 to 12.

However, in each figure, A shows the details of the vicinity of the cylinder 60, and B shows the relative position of the fork 1 and the face plate 30.

If, FIG. 9 shows the state of the face plate 30 immediately before extrusion.

The pantograph 20 is retracted and the gripper 90
abuts the lower flange 110b of the gripper channel 110.

FIG. 10 shows a state in which extrusion of the face plate 30 has started.

Pressure oil is sent to the cylinder 60 on the rond side.

At this time, due to the expansion resistance of the pantograph 20, the cylinder 6
Since the frictional resistance between the first small diameter portion 60a of 0 and the liner 112 is much smaller, the piston rod 61 and the link 20a remain stationary, and the cylinder 60 and the gripper 90 integrated with it rise to release the gripper. channel 11
0 comes into contact with the upper 7 flange 110a.

Then, as shown in FIG. 11, the piston rod 61 starts to descend within the cylinder 60 where the gripper 90 is prevented from rising by the upper flange 110a, and by pulling down the horizontal frame 40, the link 20a is engaged with the horizontal frame 40. The joint is pulled down and the pantograph 20 is extended forward.

Therefore, the cargo C is pushed forward as shown in FIG. 11B.

Once the cargo C has been pushed out to a predetermined position, the vehicle is moved backward to remove the edge of the sheet pallet from the gripper channel 110, and then the pressure oil is introduced into the piston side of the cylinder 60 and the rond side into the tank. When connected, the cylinder 60 with low resistance first descends, and the gripper 90 abuts the lower flange 110b, then the piston rod 61 rises, the horizontal frame 40 rises, and the pantograph 20 contracts. I am made to do so.

(FIG. 12) Furthermore, when pulling in the cargo C, as shown in FIG. 13, if pressure oil is sent to the piston side, the gripper 90 first descends.

At this time, the face plate 30 is advanced in advance so that the edge of the sheet pallet P faces into the gripper channel 110.

Then, the sheet pallet P is first grabbed by the lowering of the gripper 90.

After that, the piston rod 61 and the horizontal frame 40 rise, so the pantograph 20 is retracted.

At this time, the sheet pallet P is almost grabbed, so the cargo C on top of it is pulled and pulled onto the fork 1.

However, in order to pull the cargo C while gripping the sheet pallet P, the gripping force of the gripper 90 due to the hydraulic pressure determined by the resistance when expanding and contracting the pantograph 20 must be made sufficiently large, otherwise the pallet P will be pulled out and the cargo C will be left behind. There is a risk of being exposed.

Therefore, it is desirable that the engaging portion of the gripper not only be engaged by fitting the concave and convex stripes, but also have a rough gripping surface to provide sufficient gripping force.

In this embodiment, the piston rod 61 of the cylinder 60 is pivotally connected to the horizontal frame 40, and the extension part (second small diameter part 60
b) was connected to the gripper 90, but conversely, the extension part was connected to the horizontal frame 4.
It is also possible to connect the piston rod 61 to the gripper 90 .

As detailed above, the present invention comprises a fork fixed to a lift bracket of a forklift truck, a frame fixed upright to the lift bracket, a link whose lower end is pivotally supported by the frame, and the frame. A pair of pantographs each having at least one link mechanism in which the upper end of the pantograph is pivoted to each other in an X-shape and another link whose upper end is guided so as to be raised and lowered, and each lower part of the link at the tip of the pair of pantographs. The face plate is pivotally supported at the end and guides each upper end of another link at the tip thereof in a vertically movable manner, and is moved forward and backward above the fork as the pantograph expands and contracts, and includes an upper flange and a lower flange. A gripper channel having a lever-shaped cross-sectional shape and fixed to the lower end of the face plate with the opening facing forward, and a gripper channel having a longitudinal shape and movable between an upper flange and a lower flange within the gripper channel. A push-pull attachment comprising: a gripper which is provided and grips an edge of the seat panel in cooperation with a lower flange; a gripper drive means for actuating the gripper; and a pantograph drive means for extending and retracting the pantograph. The upper ends of the links at the tip of the pantograph are connected to each other by a horizontal frame, and between the horizontal frame and the gripper, a piston rod is extendable and retractable from one end, and an extension is provided from the other end. Attach the cylinder by pivoting one of the piston rod and the extension to the horizontal frame and connecting the other to the gripper by passing through the upper flange of the gripper channel, and the piston rod of the cylinder The extension/contraction stroke of the gripper is set to be greater than or equal to the sum of the maximum movement amount of the gripper within the gripper channel and the amount of elevation and descent of the horizontal frame required to extend/retract the pantograph, thereby causing the cylinder to serve as both the gripper drive means and the pantograph drive means. It is characterized by this.

Therefore, according to the present invention, it is possible to have one cylinder serve as a driving means for both pushing out the cargo and pulling in the cargo by grasping the sheet pallet.

This is the first effect of the present invention.Therefore, there are only three control valves, including the two control valves for the mast lifting and tilting functions, and the number of piping is reduced accordingly. is the second effect.

The change from four control valves to three control valves not only has the effect of directly reducing cost and weight, but also has ripple effects such as reducing the space required for the cab, making driving easier, and reducing the nervous burden. Great effect.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of a conventional push-pull attachment for a forklift truck, and FIG. 2 is a side view of the vicinity of the gripper of the push-pull attachment. FIG. 3 is a circuit diagram showing a known hydraulic system for driving a lift bracket to which a push-pull attachment is attached. FIG. 4 is an external perspective view of the vicinity of the face plate of a bush pull attachment which is an embodiment of the present invention. FIG. 5 is an exploded perspective view of the cylinder and its vicinity of the push-pull attachment shown in FIG. 4, and FIG. 6 is a horizontal sectional view showing a connecting portion between the cylinder and the pantograph in the push-pull attachment. 7 is a partially enlarged view of the face plate shown in FIG. 4, and FIG. 8 is a sectional view taken along line 8-8 in FIG. 4. FIGS. 9 to 13 are explanatory diagrams showing the operating states of the push-pull attachments shown in FIGS. 4 to 8. 1: Fork, 5: Guide rail, 12: Lift bracket, 20: Pantograph, 20a. 20b: link, 30: face plate, 40: horizontal bar, 60: push/gripper cylinder, 60a: first small diameter section, 60b: second small diameter section, 61: piston rod, 9
0 nigeritsupa, 110 nigeritsupati yannel, 110a
: Upper flange, 110b: Lower flange.

Claims (1)

[Scope of Claims] 1. A fork fixed to a lift bracket of a forklift truck, a frame also fixed upright to the lift bracket, a link whose lower end is pivotally supported to the frame, and an upper end to the frame. a pair of pantographs each having at least one link mechanism in which a link mechanism is pivotally connected to each other in an X-shape and another link guided so as to be movable up and down; a face plate that is supported while movably guiding each upper end of the other link at the tip end, and that is moved forward and backward above the fork as the pantograph expands and contracts; an upper flange and a lower flange; a gripper channel having a U-shaped cross-sectional shape and fixed to the lower end of the face plate with the opening facing forward; a push-pull attachment comprising: a gripper movably disposed at the lower flange to grip an edge of the seat panel in cooperation with the lower flange; gripper drive means for actuating the gripper; and pantograph drive means for extending and retracting the pantograph. The upper ends of the foremost links of the pair of pantographs are connected by a horizontal frame, and a piston rod is extendably extended from one end between the horizontal frame and the gripper. , a cylinder with an extension extending from the other end,
One of the piston rod and the extension is pivotally mounted to the horizontal frame, and the other is attached by passing through the upper flange of the gripper channel and connecting to the gripper, and the extension stroke of the piston rod of the cylinder. is greater than or equal to the sum of the maximum movement amount of the gripper within the gripper channel and the amount of elevation and descent of the horizontal frame required to extend and contract the pantograph, thereby attaching the gripper drive means and pantograph drive means to the cylinder. A push-pull attachment for forklift trucks that doubles as a push-pull attachment.