JPS63272788A - Back rest positioning device for forklift - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a backrest positioning device for a 7-au lift.

Conventional technology A system in which the backrest on the fork pawl is moved forward and backward using a link mechanism and a cylinder mechanism to adjust the actual importance of the fork is disclosed, for example, in Japanese Utility Model Application No. 58-192.
It is also shown in the No. 897 publication.

Problems to be Solved by the Invention The link mechanism is equipped with a slider at the end of the link, and this slider can be expanded and contracted by sliding up and down along a guide mast and/or a backrest installed upright on a carriage. ing. However, even if the length of the fork claws is adjusted to match the pallet by moving the backrest forward or backward, the loaded cargo collides with the backrest during cargo handling operations, and an external force acts on the backrest in the backward direction. Due to looseness in the link mechanism or air bubbles mixed in the hydraulic oil of the cylinder mechanism, the link mechanism is compressed and the backrest moves slightly rearward. For this reason, even if you take the trouble to adjust the length of the fork's claws appropriately to match the pallet being used, the problem with the backrest? ! Due to the retraction, the tips of the claws sometimes protruded beyond the edge of the pallet, damaging preloaded cargo and pallets. Therefore, even if an external force acts on the backrest in the backward direction, the present invention suppresses the reduction displacement of the link mechanism and prevents the backrest from following in the backward direction, thereby making it possible to reliably determine the position of the backrest. A forklift backrest positioning device is provided.

Means for solving the problem A pair of guide masts are fully mounted on a carriage with a fork mounted thereon, and a slider at the end of the link is inserted between the guide masts and the backrest on the claw of the fork. Slide up and down along the rest and extend, a
In the structure in which all the link mechanisms are disposed, and an unlinder machine *'e is disposed astride the guide mast and the link mechanism to extend and contract the link mechanism to move the backrest forward and backward on the pawl of the fork. When an external force acts on the backrest in the backward direction, a braking surface whose friction coefficient is increased by surface treatment is installed on one side of the sliding surface where the slider, guide mast, and/or backrest collide with each other. It is formed.

During loading and unloading work, the loaded baggage collides with the backrest,
When an external force acts on the backrest in the backward direction, the slider at the link end of the link mechanism and the guide mast and/or backrest collide with each other, and their braking surfaces and sliding surfaces come into pressure contact, causing the slider to slide. This prevents the link mechanism from moving backwards, and therefore prevents the backrest from moving backwards.

actual example Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 to 3, reference numeral 1 indicates a carriage in which a fork 3 is attached to a finger bar 2, and an upper beam 5 is attached to the upper end of the finger bar 2@ surface of this carriage 1.
A pair of guide masts 4 having an opening-shaped cross section are arranged. Reference numeral 6 denotes a slider that is fitted and attached to these guide masts 4 so as to be able to slide vertically, and an upper link 7 is provided at each upper and lower end.
, the rear end of the lower link 8 is connected with a pin. Left and right Atsuha IJ links 7. The lower links 8 are connected to each other by reinforcing beams 9 and 10 at their intermediate portions, and each upper link 7
, the front end of the lower link 8 is connected with a pin to the backrest 11 on the pawl 3a of the fork 3 at a position offset downward from the connection point with the slider 6, so that the slider 6,
Upper link 7, lower link 8. The backrest 11 constitutes a parallel link machine 11112. Reference numeral 13 denotes a cylinder mechanism disposed astride the guide mast 4 and the parallel link mechanism 12. In this embodiment, the cylinder body 13a k is connected to the middle shaft of the upper beam 5 of the guide mast 4 with a pin, and is connected to the actuating rod 131)'. The reinforcing beam 10 of the lower link 8 is connected with a pin to the middle shaft, and the cylinder mechanism 13 is extended.
By the contraction operation, the parallel link mechanism 12 is extended and contracted, and the backrest 11 is moved forward and backward on the claw aIL of the fork 3. Of the sliding contact surfaces between the slider 6 and the guide mast 4, when an external force in the backward direction is applied to the bag rest 11, the sliding contact surface on the side where the slider 6 and the guide mast 4 collide with each other; In this embodiment, a braking surface 14 whose friction coefficient is increased by surface treatment is formed on either the rear surface of the slider 6 or the inner surface of the rear wall of the guide mast 4, for example, on the rear surface of the slider 6.

This braking surface is knurled and shot peened.

It can be obtained by surface treatment such as blasting, etching, coating with a resin material having a large friction coefficient, or adhesion. This braking surface 14 is, of course, the guide mast 4
It may also be formed on the inner surface of the rear wall.

According to the above-described embodiment, when the cylinder machine 113 is extended or contracted, the slider 6 of the parallel link mechanism 12 slides in the vertical direction within the guide mast 4, causing the parallel link machine W12 to extend or contract, and back up. Rest 11' (i-Move forward or backward on the pawl 3a of the fork 3 to determine the actual length of the pawl 3a of the fork 3, that is, the length L from the tip ρ of the pawl 3a to the backrest 11. It can be adjusted arbitrarily depending on the length of the outer pallet or the load.On the other hand, if a loaded load collides with the backrest 11 during cargo handling and an external force acts on the backrest 11 in the backward direction, the slider Since the braking surface 14 on the rear side of the guide mast 4 is in pressure contact with the inner surface of the rear wall of the guide mast 4, upward sliding of the slider 6 is suppressed, reducing the reduction displacement of the parallel link machine gt12, and thus the backrest [1
The backward movement of the backrest 11 is prevented, and the positioning of the backrest 11 can be ensured.

In the embodiment shown in FIG. 4, a backrest 11 is connected to a claw 3a by a pair of pantograph link mechanisms 15 and a cylinder mechanism 13 in which links 16 and 17 are connected with a pin at the center.
It was designed to move forward and backward at the top.

A pair of guide rails 18 corresponding to the guide mast 4 are formed on the backrest 11. The lower ends of the links 16 and 17 of the pantograph link mechanism 15 are connected to the guide mast 4. It is connected to the guide rail 18 with a pin. Also,
A slider 19 at the upper end of these links 16 and 17,
2u is the guide mast 4. It is fitted into the guide rail 18 so that it can slide up and down automatically. A pair of cylinder machines [13 is the cylinder body 13a? Pins are connected to the left and right guide masts 4 of the upper beam 5, and the operating rods 13 t)
? The links 17 of the left and right pantograph link mechanisms 15 are connected by pins near the rear ends. Therefore, by the synchronous expansion and contraction operations of the pair of cylinder mechanisms 13, the left and right pantograph link mechanisms 15 are synchronously expanded and contracted, and the backrest 11? The substantial importance can be arbitrarily adjusted by moving the bar forward and backward on the pawl 3a of the fork 3. Then, in accordance with the same purpose as in the embodiment described above, for example, a rear side surface of the slider 19 is attached to either one of the sliding contact surfaces of the slider 19 and the guide mast 4, and one of the sliding contact surfaces of the slider 20 and the guide rail 18. , braking surfaces 21 and 22 on the front side of the slider 20, respectively.
K is formed. Therefore, according to this embodiment, when a load to be taken in collides with the backrest 11 during cargo handling work and an external force is applied to the backrest 11 in the backward direction, the braking surface 21 on the rear side of the slider 19 is moved behind the guide mast 4. At the same time, the brake ff122 of the slider 2 (Jcoon fil! surface) comes into pressure contact with the inner surface of the front wall of the guide rail 18, and the upward sliding of these sliders 19 and 20 is suppressed, and the pantograph link machine The contraction displacement of l1115 and therefore the backward movement of the backrest 11 is prevented, and the positioning of the backrest 11 can be ensured.

Effects of the Invention As described above, according to the present invention, when a loaded load collides with the backrest and an external force in the backward direction is applied to the backrest, the slider at the link end of the ring mechanism slides. A braking surface with a large friction coefficient formed on one of the sliding surfaces of the guide mast and/or the backrest presses against the other sliding surface and suppresses the sliding of the slider, thereby reducing the reduction displacement of the link mechanism. This has a great practical effect in that it is possible to prevent the backrest from moving backwards and to ensure the positioning of the backrest.

[Brief explanation of the drawing]

FIG. 1 is a side view showing one embodiment of the present invention, and FIG. 2 is a side view showing one embodiment of the present invention.
3 is a sectional view taken along the line ``--'' in the figure, FIG. 3 is a sectional view taken along the line ``T'' in FIG. 2, and FIG. 4 is a side view 9 showing a different example of the present invention. 1... Carriage, 3... Fork, 3a... Claw, 401. Guide mast, 6...Slider, 11...
・Backrest, 12... Parallel link mechanism (link mechanism), 13... Cylinder mechanism, 14... Braking 1.1
5... Pantograph type link mechanism (link mechanism), 1
9, 20...Slider, 21°22...Braking surface. Figure 1 1-1-Yari list 12--Ippei link or book (Refuka Eating Course) 3-11 Fuzouk 13--
-Cylinde Gakko 6---Slider 19.20-
Spive 11 --- High Lambda Recrest 21.22-Shield 1st page 2nd figure 3rd page

Claims (1)

[Claims] (1) A pair of guide masts are arranged on the carriage with the fork attached, and the slider at the end of the link slides up and down along the guide mast and/or the backrest, straddling these guide masts and the backrest on the claw of the fork. A link mechanism that moves to extend and contract is provided, and a cylinder mechanism is provided spanning the guide mast and the link mechanism to extend and contract the link mechanism to move the backrest forward and backward on the pawl of the fork. In the structure, when an external force is applied to the backrest in the advance/retreat direction, a friction coefficient is reduced by surface treatment on one of the sliding surfaces of the slider, the guide mast, and/or the backrest that come into contact with each other. A forklift backrest positioning device characterized by forming a large braking surface.