JP2000296999A - Fork tilting mechanism of cargo handling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically tilt forks at a low cost and in simple structure. SOLUTION: Both ends of a connection shaft 3b on which a pair of forks 4 are fitted are inserted into a pair of the right and left long holes 16 of a lift body 3, and a spring 10 for energizing the connection shaft 3b upward intervenes in each hole 16, and a tilting means 11 comprising a pair of cams 20 and 21 firmly fixed to the faces of the horizontal beam 3d of the lift body 3 and each fork 4, which oppose to each other is provided. When a workpiece is lifted by each fork 4, the springs 10 are compressed due to the weight of the workpiece, descending each fork 4. Through this operation, the cam 21 on the side of the forks is made to slide along the cam face 20a of the cam 20 on the side of the lift body 3, as a result, each fork 4 turns (g) upward around the connection shaft 3b, being tilted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fork tilt mechanism for a cargo handling device which lifts a workpiece by a fork such as a reach-type forklift or a manual lift.

[0002]

2. Description of the Related Art FIGS. 8 and 9 show an example of a conventional reach type forklift. A mast 2 is provided at the front of a vehicle body (a cargo handling device body) 1 having a drive tire 1a, a caster tire 1b, and a road wheel 1c.
Are arranged so as to be able to move forward and backward a and b, and a pair of left and right forks 4 is attached to an elevating body 3 that can move up and down c and d on the mast 2.

The elevating body 3 includes a backrest 3a and a connecting shaft 3b horizontally installed at the center of the backrest 3a.
And a substantially U-shaped connecting frame 3c, and a horizontal girder 3d provided under the backrest 3a.

Each of the forks 4 is formed in a substantially L-shape in a side view, and a through-hole formed at an upper end of a base vertical portion 4a thereof is fitted to the connecting shaft 3b to thereby form the connecting shaft. The fork 4 is held substantially horizontally by being configured to be movable along 3b, and by bringing the base vertical portion 4a into contact with the cross beam 3d. In FIG. 9, reference numeral 5 denotes a positioning bolt which is engaged with the upper end of each fork 4 through the through hole of the connection frame 3c.

In the above structure, when the workpiece W is transported, the lifting body 3 is lowered from the state shown by the solid line in FIG. The fork 4 is inserted into the pallet P (see the dashed line in FIG. 8), the lifting body 3 is raised, the work W is lifted by both forks 4, the body 1 is moved, and the work W is transported to a predetermined position. Has become.

In the above-described conventional configuration, since the work W is only vertically lifted by the horizontal portion 4b at the tip end of the fork 4, the support of the work W during transportation tends to be unstable.

Therefore, as shown by the imaginary line in FIG. 8, the mast 2 is divided into a mast main body 2a and a mast lower part 2b, and both of them 2a and 2b are rotatably connected by a pivot shaft 7. A hydraulic cylinder 8 for tilting and moving the mast main body 2a about the pivot shaft 7 is provided, and after the work W is lifted by the fork 4,
It is conceivable that the mast main body 2a is tilted back f by the hydraulic cylinder 8 to push the work W against the backrest 3a, and the backrest 3a and the fork 4 stably support and convey the work W.

[0008]

According to the above construction, a large modification such as dividing the mast 2 into a mast main body 2a and a mast lower part 2b is required, and the construction becomes complicated.
Further, since an expensive hydraulic cylinder 8 and the like are required, the production cost is high.

The present invention has been made in view of the above-mentioned conventional drawbacks, and has as its object to provide a fork tilt mechanism of a cargo handling device capable of automatically tilting a fork with an inexpensive and simple configuration.

[0010]

According to a first aspect of the present invention, there is provided a cargo handling apparatus in which a fork for lifting a work is mounted on a vertically movable body on a body of the cargo handling apparatus. An urging means attached to the elevating body so as to be able to ascend and descend and rotatably urges the fork upward, and a tilt means for tilting the fork lowered downward against the urging means are provided. Features.

According to the above construction, the work is stably supported and conveyed by simply lifting the work by the fork and lowering the fork by the weight of the work and automatically tilting the work by the tilting means. Can be
In this case, it is only necessary to make a slight change to the existing cargo handling device, so that the configuration is simple and the production cost can be reduced.

According to a second aspect of the present invention, in the first aspect of the invention, the fork is rotatably connected to a connecting shaft provided on the elevating body, and the gap for allowing the fork to move up and down is provided. It is characterized in that it is formed between the connecting shaft and the elevating body or fork.

According to the above configuration, the fork can be moved up and down and rotated with a simple structure in which only a gap is formed between the connecting shaft for connecting the fork and the elevating body or the fork. Production costs are low.

According to a third aspect of the present invention, in the second aspect of the invention, the space is formed by a pair of left and right vertically long holes formed in the elevating body, and each of the long holes is provided with the connecting shaft. It is characterized in that both ends are movably inserted.

According to the above construction, since both ends of the connecting shaft connecting the forks are movably inserted into the pair of right and left vertically long holes formed in the elevating body, the forks are moved along the long holes. The fork can be raised and lowered smoothly, and the fork can be smoothly rotated about the connecting shaft.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the urging means comprises a spring for urging the connecting shaft upward.

According to the above construction, the urging means is composed of a spring, the construction is simple, the manufacturing cost is low, and the fork can be surely urged upward via the connecting shaft.

According to a fifth aspect of the present invention, in the fourth aspect of the invention, the tilt means comprises a cam provided on both or one of opposing surfaces of the elevating body and the fork. The fork which descends against the spring by a cam is tilted.

According to the above configuration, the fork is tilted by the cam instead of the conventional hydraulic cylinder, so that the structure is simple and the manufacturing cost can be reduced.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, a cam is provided on one of the opposing surfaces of the elevating body and the fork.
A cam follower is provided on the other side, and a cam surface of the cam is inclined obliquely forward and downward, and the cam follower is in contact with the cam surface.

According to the above configuration, the fork can be reliably tilted by a simple combination of the cam and the cam follower.

According to a seventh aspect of the present invention, in the sixth aspect of the invention, the cam follower comprises a guide roller.

According to the above configuration, the guide roller is brought into contact with the cam surface of the cam, and the frictional resistance between the two is small, so that the fork can be smoothly tilted.

According to an eighth aspect of the present invention, in the first aspect of the present invention, the cargo handling apparatus main body is a body of a reach type forklift.

According to the above configuration, it is possible to provide a reach type forklift having a simple and inexpensive fork tilt mechanism.

[0026]

1 and 2 show a reach type forklift provided with a fork tilt mechanism according to a first embodiment of the present invention.
Are attached to the elevating body 3 so as to be able to ascend and descend and rotate via a connecting shaft 3b, and a pair of right and left springs (biasing means) 10 for urging the forks 4 upward, and descend against the springs 10. And a tilting means 11 for tilting each of the forks 4. In the configuration other than the above, the same parts as those of the conventional example shown in FIGS.

As shown in FIGS. 3 to 5, each of the forks 4 has a through hole 12 formed at an upper end of a base vertical portion 4a.
Is rotatably fitted to the connecting shaft 3b, and is suspended from the backrest 3a of the elevating body 3 via the connecting shaft 3b.

The backrest 3a is divided into an upper frame portion 13 and a pair of left and right lower frame portions 14, and a connecting frame 3c is interposed between the two lower frame portions 14. Part 1
4a and both ends of the upper frame portion 13 are fastening members 15 such as bolts.
Are connected integrally. In addition, a pair of left and right vertically long holes (voids) 16 are formed through the upper end portion 14a of each lower frame portion and the end of the connection frame 3c, and both ends of the connection shaft 3b are formed in the respective long holes 16. It is inserted movably. Further, a fixed shaft 17 made of a bolt or the like is movably inserted into the through hole 18 of the connecting shaft 3b through the central portion of each long hole 16 so that the connecting shaft 3b is unexpectedly inserted from the long hole 16. In order not to fall off.

As shown in FIGS. 3 and 4, the spring 10 is fitted around the fixed shaft 17 and is interposed between the bottom surface of the long hole 16 and the lower surface of the connecting shaft 3b. When the work W is not lifted, the connection shaft 3b is pushed up (see FIG. 3). When the work W is lifted by the fork 4, the connection shaft 3b loses the weight of the work W and moves down by the predetermined interval α. Allow.

In the above configuration, the elongated hole 16 is formed in the backrest 3.
a, but instead of this, a slot 16 is formed in the fork 4
May be formed on the base vertical portion 4a. Further, the fork 4 may be pulled upward by extending the spring 10 out of the elongated hole 16 and extending the spring between the back shaft 3a and the connecting shaft 3b or the fork 4.

The tilt means 11 comprises a pair of cams 20 and 21 provided on opposing surfaces of the cross beam 3d of the elevating body 3 and the base vertical portion 4a of the fork 4, respectively. , 21 slidably contacting cam surfaces 20
a and 21a are inclined obliquely forward and downward. In the above configuration, when the work W is transported,
As in the prior art, from the state shown by the solid line in FIG. 1, the elevating body 3 is lowered to make the forks 4 face the pallet P, the vehicle body 1 is advanced a, and the forks 4 are inserted into the pallet P (FIG. 1). The work W is lifted by the forks 4 by raising the elevating body 3. by this,
The weight of the work W is applied to each spring 10, and each spring 10
Is compressed, and the connecting shaft 3b and each fork 4
(See phantom line in FIG. 3).

When the forks 4 are lowered, the fork-side cams 21 slide along the cam surfaces 20a of the elevating body-side cams 20, whereby the forks 4 are rotated upward about the connecting shafts 3b. The fork 4 is automatically tilted, whereby the tip horizontal portion 4b of each fork 4 is inclined upward, and the work W on each fork 4 is pressed against the backrest 3a. 3a and is stably supported. Then, the car body 1
, The work W can be transported to a predetermined position.

According to the above structure, the work W is stably supported by simply lifting the work W by the fork 4 and lowering the fork 4 by the weight of the work W and automatically tilting the work W by the tilting means 11. Can be transported.

Further, since only a slight change is required to the elevating body 3 of the existing reach type forklift, the manufacturing cost can be reduced.

Further, a conventional hydraulic cylinder 8 (see FIG. 8)
Instead, the forks 4 are tilted by the cams 20 and 21, so that the structure is simple and the production cost can be reduced.

In the first embodiment, the tilt means 11
Although a pair of cams 20 and 21 are used as the above, the present invention is not limited to this. As shown in FIG. 6, the cam 20 is provided on the cross beam 3d, and the guide roller ( A cam follower 23 may be provided, and the guide roller 23 may be brought into contact with the cam surface 20a of the cam 20 (second embodiment), and as shown in FIG. A cam 21 is provided on 4a, and a guide roller (cam follower) 23 is provided on the horizontal beam 3d.
The cam surface 21a of the cam 21 may be brought into contact with the guide roller 23 (third embodiment).

According to the above configuration, since the frictional resistance between the cams 20 and 21 and the guide roller 23 is small, the fork 4 can be smoothly tilted.

In each of the above embodiments, a reach type forklift has been described as an example. However, the present invention is not limited to this, and can be applied to various types of cargo handling devices such as a manual lift.

[0039]

According to the first aspect of the present invention, the work is stably supported by simply lifting the work with the fork, and the fork is lowered by the weight of the work and automatically tilted by the tilting means. In this case, it is only necessary to make a slight change to the existing cargo handling device, so that the configuration is simple and the production cost can be reduced.

According to the second aspect of the present invention, the fork can be moved up and down and rotated with a simple structure in which only a gap is formed between the connecting shaft for connecting the fork and the elevating body or the fork. And production costs are low.

According to the third aspect of the present invention, since both ends of the connecting shaft to which the fork is connected are movably inserted into the pair of left and right vertically long holes formed in the elevating body. The fork can be smoothly moved up and down along with the fork, and the fork can be smoothly rotated about the connecting shaft.

According to the fourth aspect of the present invention, the urging means is formed of a spring, the structure is simple, the manufacturing cost is low, and the fork can be surely urged upward via the connecting shaft.

According to the fifth aspect of the present invention, the fork is tilted by the cam instead of the conventional hydraulic cylinder, so that the structure is simple and the manufacturing cost can be reduced.

According to the sixth aspect of the present invention, the fork can be reliably tilted by a simple combination of the cam and the cam follower.

According to the seventh aspect of the present invention, since the guide roller is in contact with the cam surface of the cam and the frictional resistance between the two is small, the fork can be smoothly tilted.

According to the invention described in claim 8, a reach type forklift having a simple and inexpensive fork tilt mechanism can be provided.

[Brief description of the drawings]

FIG. 1 is a side view showing a reach type forklift provided with a fork tilt mechanism according to a first embodiment of the present invention.

FIG. 2 is a front view of the same.

FIG. 3 is a longitudinal sectional view of the main part.

FIG. 4 is a partially cutaway front view of the main part.

FIG. 5 is an exploded perspective view of the main part.

FIG. 6 is a longitudinal sectional view of a main part of a fork tilt mechanism according to a second embodiment of the present invention.

FIG. 7 is a longitudinal sectional view of a main part of a fork tilt mechanism according to a third embodiment of the present invention.

FIG. 8 is a side view showing a conventional example.

FIG. 9 is a front view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body (Cargo handling apparatus main body) 3 Lifting body 3a Backrest 3b Connecting shaft 3c Cross beam 4 Fork 10 Spring (biasing means) 11 Tilt means 16 Slot (void) 20 Cam 20a Cam surface 21 Cam 21a Cam surface 23 Guide roller (Cam follower)

Claims (8)

[Claims] 1. A loading / unloading device in which a fork for lifting a work is attached to a vertically movable lifting / lowering body on a loading / unloading device main body. A fork tilt mechanism for a cargo handling device, comprising: urging means for urging; and tilt means for tilting a fork lowered against the urging means. 2. The fork is rotatably connected to a connecting shaft mounted on the elevating body, and a gap is formed between the connecting shaft and the elevating body or fork to allow the fork to move up and down. The fork tilt mechanism of a cargo handling device according to claim 1, wherein 3. The air gap comprises a pair of left and right vertically long holes formed in the elevating body, and both ends of the connecting shaft are movably inserted into each of the long holes. A fork tilt mechanism for the cargo handling device according to claim 2. 4. The fork tilt mechanism for a cargo handling device according to claim 3, wherein said urging means comprises a spring for urging said connecting shaft upward. 5. The tilt means comprises a cam provided on both or one of opposing surfaces of the elevating body and the fork, and the cam causes the fork to descend against the spring by the cam. The fork tilt mechanism for a cargo handling device according to claim 4, wherein 6. A cam is provided on one of the opposing surfaces of the elevating body and the fork, and a cam follower is provided on the other surface, and the cam surface of the cam is inclined downward. 6. The fork tilt mechanism for a cargo handling device according to claim 5, wherein the cam follower is inclined forward and the cam follower is in contact with the cam surface. 7. The fork tilt mechanism according to claim 6, wherein the cam follower comprises a guide roller. 8. The fork tilt mechanism of a cargo handling device according to claim 1, wherein the cargo handling device body is a body of a reach type forklift.