JPH09227094A - Tilt beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tilt beam capable of easily arranging cargo handling apparatuses in a layout space. SOLUTION: A tilt beam 4 is suspended between a pair of outer masts arranged on both the right and left sides of a fork-lift. The tilt beam 4 is used to prevent the twist of the outer masts 1 when the outer masts 1 are inclined, and it is constituted of an outer beam 11, an inner beam 12, and ribs 13a, 13b. The outer beam 11 is formed into a U-shape, and the space surrounded by the outer beam 11 and the outer masts 1 becomes a layout space D where cargo handling apparatuses are arranged. A lift cylinder 14, a chain wheel 15, and a high-pressure hose 16 are arranged as the cargo handling apparatuses. The inner beam 12 is arranged on the inside of the outer beam 11 to avoid various cargo handling apparatuses. The ribs 13a, 13b are welded between the outer beam 11 and the inner beam 12 to reinforce the tilt beam 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tilt beam fixed to an outer mast of a forklift.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 7, a pair of outer masts 31 arranged on both left and right front portions of a forklift.
Are connected by a U-shaped tilt beam 32 shown in FIG. Each outer mast 31 is appropriately tilted (tilted) based on expansion and contraction of a tilt cylinder (not shown). When the outer mast 31 tilts, a twisting moment in the direction of the arrow Y2 acts on the outer mast 31. The tilt beam 32 prevents each outer mast 31 from being twisted by this twisting moment.

A cargo handling device such as a lift cylinder for performing various cargo handling operations is arranged in an arrangement space 33 surrounded by the tilt beam 32, the outer masts 31 and the like.

[0004]

By the way, the cargo handling work of the forklift is performed by the fork located in front of the outer mast 31. Normally, when a load is placed on a fork, a tilting moment that tends to tilt the forklift about the front wheel acts forward. This tilting moment is a value obtained by multiplying the distance from the front wheel to the position of the load by the weight of the load. Therefore, if the position of the load from the front wheel, that is, the distance from the front wheel to the fork is increased, the tilting moment increases, and the forklift itself tends to tilt forward. For this reason,
The weight of the load that can be placed on the fork (maximum load weight) is small.

Therefore, in order to reduce this tilting moment, make it difficult for the forklift to tilt forward, and increase the maximum load weight, it is necessary to bring the fork closer to the rear (front wheel side of the forklift) as much as possible. .
Therefore, there is a limitation in expanding the arrangement space 33 for arranging the cargo handling equipment such as the lift cylinder forward and arranging the outer mast 31 by moving it forward.

Nevertheless, when the fork is moved rearward, the arrangement space 33 shrinks, so that cargo handling equipment such as a lift cylinder that requires a certain dimension to maintain cargo handling performance, that is, to accommodate the maximum load capacity. Not only is the installation position limited, but in some cases it is difficult to even secure the installation position in the cargo handling equipment. Moreover, behind the tilt beam 32, a plate for partitioning the driver's cab and the mast device such as the outer mast 31 is arranged. Therefore, the tilt beam 32 is extended rearward,
It is also difficult to expand the arrangement space to the rear.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a tilt beam in which a cargo handling device can be easily arranged in an arrangement space.

[0008]

In order to solve the above-mentioned problems, the invention according to claim 1 is such that a pair of outer masts arranged on both left and right sides of a forklift are connected so as to be suspended, and the outer surface of each outer mast is connected. An outer beam having a tip portion fixed to a part of the inner beam, an inner beam arranged in the arrangement space so as to avoid a cargo handling device in the arrangement space surrounded by the outer mast and the outer beam, and the outer beam. The gist of the invention is to include a connecting member that connects the beam and the inner beam to each other.

A second aspect of the invention is based on the first aspect of the invention, wherein the connecting member is a rib arranged between the outer beam and the inner beam.
According to a third aspect of the present invention, in the first or second aspect of the invention, the outer beam is bent in a U shape and is fixed so as to be convex toward the rear of the outer mast. To do.

According to a fourth aspect of the present invention, in the first to third aspects of the present invention, lift cylinders for raising and lowering forks are disposed as cargo-handling equipment on the left and right sides of the arrangement space, and the inner beam is the same. Its gist is that it is bent so as to avoid the lift cylinder.

According to a fifth aspect of the invention, in the fourth aspect of the invention, a wide portion is formed in the inner beam so as to widen a distance between the inner beam and the outer beam, and the wide portion is formed. The gist is that the ribs are arranged between the outer beam and the outer beam.

A sixth aspect of the present invention is the gist of the fifth aspect of the invention, in which the wide portion of the inner beam is parallel to the outer beam. The gist of the invention described in claim 7 is that, in the invention described in claims 2 to 6, ribs fixed to the outer mast are respectively arranged between both ends of the outer and inner beams.

Therefore, according to the first aspect of the present invention, the tilt beam is composed of the outer beam and the inner beam, and the inner beam is attached so as to avoid the cargo handling equipment in the arrangement space. The degree of freedom in selecting the location of the cargo handling equipment is increased. Further, by connecting the outer beam and the inner beam, the intensity of the tilt beam is improved.

According to the second aspect of the invention, the connecting member can easily reinforce the tilt beam by disposing the rib between the outer beam and the inner beam. According to the third aspect of the invention, since the outer beam is formed in a U-shape, the arrangement space is formed wide.

According to the fourth aspect of the invention, lift cylinders for raising and lowering the forks are disposed as cargo-handling equipment on the left and right sides of the arrangement space, and the inner beam is bent so as to avoid the lift cylinders. Has been done.
In this case, the lift cylinder can be easily avoided by bending the inner beam.

According to the fifth aspect of the present invention, a wide portion is formed in the inner beam so as to widen the distance between the lift beam and the outer beam, and a rib is formed between the wide portion and the outer beam. The intensity of the tilt beam is increased by arranging. Since the portion where the wide portion is formed is the portion where the tilt beam strength is most required, that is, the portion where the moment load is most applied, the width is widened as described above and the strength is increased by providing the rib. There is.

Further, by providing the ribs, it is possible to increase the strength while maintaining the degree of freedom in selecting the position where various cargo handling devices are arranged in the arrangement space. Claim 6
According to the above-mentioned invention, since the wide portion of the inner beam is parallel to the outer beam, the range of the wide portion can be made as long as possible, and the intensity of the tilt beam can be increased.

According to the seventh aspect of the present invention, the ribs fixed to the outer mast are respectively provided between the tips of the outer beam and the inner beam, so that the strength of the tilt beam can be enhanced. In this case, stress is likely to be concentrated at the fixed portion between the outer mast and the outer and inner beams, but this rib can cope with the stress concentration.

Further, by providing this rib, it becomes possible to increase the strength while maintaining the degree of freedom in selecting the position where the various cargo handling equipment is arranged in the arrangement space.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a front view of a pair of left and right outer masts 1 and the like arranged on both front left and right sides of a forklift, and FIG. 2 is a side view thereof. Each outer mast 1 is provided with a pair of left and right inner masts (not shown) that can be raised and lowered, and a fork for loading and unloading (not shown) according to the raising and lowering of these inner masts.
Is designed to move up and down.

In the lower part of each outer mast 1, there is formed an axle hole 2 through which the axle of the front wheel of the forklift is inserted. A shaft pin P is fixed to each outer mast 1, and the shaft pin P and the forklift main body are connected via a tilt cylinder 3. The body 3a of the tilt cylinder 3 is connected to the forklift main body, and the piston rod 3b is connected to the shaft pin P. Are linked. That is, the outer mast 1 tilts about the axle hole 2 based on the expansion and contraction of the tilt cylinder 3. That is, the axle hole 2 is the outer mast 1
The center of tilting.

Further, a tilt beam 4 is fixed to the rear surface of each outer mast 1, and the outer masts 1 are connected to each other by the tilt beam 4. The tilt beam 4 is a member for preventing twisting of each outer mast 1 due to a twisting moment acting in the direction of arrow Y1 (see FIG. 3) when the outer mast 1 tilts, for example.

As shown in FIG. 3, the tilt beam 4 is
Outer beam 11, inner beam 12 and each beam 11, 1
It is composed of ribs 13a and 13b for connecting and reinforcing the two. The outer beam 11 and the inner beam 12 of these tilt beams 4 have the same thickness, and are thicker than the conventional tilt beam 32 (in the present embodiment, referred to as "single beam 32"). Is thin.
For example, the thickness of the single beam 32 is about 19 to 25 mm, while the thickness of the outer and inner beams 11 and 12 is 6 mm.
It is about 9 mm.

The outer beam 11 is bent and formed in a U shape,
The intermediate plate portion 11a and the end plate portions 11b located on both sides of the intermediate plate portion 11a are included. Both ends of the outer beam 11 are welded to the rear surface of each outer mast 1. That is, the outer beam 11 is installed so as to suspend the outer mast 1. The outer beam 11 is located relatively outside with respect to each outer mast 1. In the present embodiment, the outer surface 11c of the outer beam 11 located closest to the forklift body is the same as the outer surface 32a of the conventional single beam 32. The outer beam 11 is attached to each outer mast 1 so that the outer beam 11 is located at substantially the same position.

The space on the inner side (front side) of the inner surface 11d of the outer beam 11 is a cargo handling device placement space (hereinafter simply referred to as "placement space") for placing various cargo handling devices.
D. The arrangement space D includes an outer beam inner space D1 surrounded by the outer beam 11, an inter-mast space D2 between the outer masts 1, and the like.

For example, a lift cylinder 1 for raising and lowering a fork is used as a cargo handling device in the outer beam inner space D1.
4, a chain wheel 15 for suspending a chain for suspending a fork, a high pressure hose 16 for supplying hydraulic oil to the lift cylinder 14, and the like are arranged. The lift cylinders 14 are arranged on both left and right sides of the outer beam inner space D1. The chain wheel 15 is installed near the inside of each lift cylinder 14. The high pressure hose 16 is connected to each lift cylinder 14.
Various cargo handling equipment and the like (not shown) are also arranged in the inter-mast space D2.

The inner beam 12 is fixed to the rear surface of each outer mast 1 so as to avoid various cargo handling equipment arranged in the arrangement space D. In this embodiment, the inner beam 1
2 is bent and formed in a substantially U shape by avoiding various cargo handling equipment, and includes an intermediate plate portion 12a and end plate portions 12b positioned on both sides of the intermediate plate portion 12a. In addition, in the middle plate portion 12a,
A convex portion 12e is formed as a wide portion that is convex inward. Incidentally, 12c is the outer surface of the inner beam 12,
2d is its inner surface.

The tip ends of both end plate portions 12b of the inner beam 12 are welded to the outer masts 1 at positions separated from the outer beam 11 by a predetermined distance. Both end plate portions 12b of the beam 12 are parallel to each other. In this case, the distance t1 between the outer surface 11c of the end plate portion 11b and the inner surface 12d of the end plate portion 12b is larger than the thickness of the conventional single beam 32.

The inner beam 12 is bent in the vicinity of the lift cylinders 14 so as to avoid the lift cylinders 14. Outer surface 1 of outer beam 11 at this bend
The distance t2 between 1c and the inner surface 12d of the inner beam 12 is smaller than the thickness of the conventional single beam 32.

After avoiding the lift cylinder 14, the inner beam 12 is further bent inward (to the side of the high pressure hose 16) as much as possible so as not to interfere with the high pressure hose 16, and the middle plate 1
A protrusion 12e is formed near the center of 2a. The convex portion 12e extends in the left-right direction on a straight line, is parallel to the outer beam 11, and is close to the high pressure hose 16. That is, in the parallel portion of the convex portion 12e, the interval t3 between the outer surface 11a of the outer beam 11 and the inner surface 12a of the inner beam 12 is larger than the interval t1.

That is, the inner beam 12 is arranged so as to be as wide as possible with the outer beam 11 while avoiding various cargo handling equipment in the arrangement space D (outer beam space D1).

On the other hand, a rib 13a is fixed to the tip of each of the end plate portions 11b and 12b. That is,
The rib 13a is welded to the end plate portions 11b and 12b and the outer mast 1. Convex portion 12e of the inner beam 12
A rib 13b is welded to the center of the outer beam 11 between the inner plate 11a and the outer beam 11. And each of these ribs 1
Outer beam 11 and inner beam 12 by 3a and 13b
Are linked.

According to this embodiment, the following (a)-
It has the effect of (h). (A) The tilt beam 4 is formed of the outer beam 11 and the inner beam 12, and the inner beam 12 is disposed in the space D (particularly the outer beam inner space D1) while avoiding cargo handling equipment such as the lift cylinder 14. It is installed in the space D.
Therefore, since the cargo handling equipment can be arranged without considering the mounting position of the inner beam 12, the degree of freedom in selecting the position where the cargo handling equipment is arranged in the arrangement space D can be increased. Further, each outer beam 11 and inner beam is a rib 1.
Since they are connected by 3a and 13b, the intensity of the tilt beam 4 can be increased.

(B) Ribs 13a and 13b as connecting members
Is disposed between the beams 11 and 12, the intensity of the tilt beam 4 can be easily increased. or,
Since the connecting member is a rib, the length of the rib, the arrangement position, the number of ribs, etc. can be appropriately changed, and the intensity of the tilt beam 4 can be adjusted according to each of these conditions. Further, since the connecting member is a rib, the rib can be easily attached to a desired position while avoiding interference with the cargo handling equipment.

(C) Since the outer beam 11 is bent and formed in a U-shape, an arrangement space D for arranging the cargo handling equipment, that is, an outer beam inner space D1 can be formed behind the outer mast 1. The space for arranging cargo handling equipment can be expanded. Further, the thickness of the outer beam 11 is thinner than the thickness of the single beam, and the mounting position of the outer surface 11c of the outer beam 11 is substantially the same as the mounting position of the outer surface 32a of the single beam 32. Therefore, as compared with the case where the single beam 32 is attached, the arrangement space D (outer beam inner space D1) can be widened by the difference in thickness. For this reason,
The degree of freedom in selecting the position where the cargo handling device is arranged in the arrangement space D can be further increased.

(D) The lift beam 14 can be easily avoided by bending the inner beam 12.
Moreover, since the lift cylinder 14 can be mounted without considering the mounting position of the inner beam 12,
It can be mounted at a desired position in the arrangement space D, for example, at a position most advantageous for the lifting operation of the fork. In this case, for example, the lifting and lowering operation of the fork based on the expansion and contraction of the lift cylinder 14 can be performed more smoothly.

(E) The tilt beam 4 is formed by making the distance t3 between the outer beam 11 and the convex portion 12e of the inner beam 12 as wide as possible and arranging the rib 13b between them to reinforce the space between the beams 11 and 12. The strength of can be further improved. In the present embodiment, the distance t2 between the outer beam 11 and the inner beam 12 at the bent position in order to avoid the lift cylinder 14 is very small, and the strength at that portion is weak. However, the strength of the tilt beam 4 as a whole can be improved by making the distance t3 between the outer beam 11 and the convex portion 12e as wide as possible and arranging and reinforcing the rib 13b.

(F) The convex portion 12e linearly forms the outer beam 1
Since it is formed in parallel with No. 1, it is possible to form a portion having excellent strength, which maintains the distance t3 with the outer beam 11, as wide as possible, and it is possible to further increase the strength of the tilt beam 4. Moreover, the parallelism improves the appearance of the tilt beam 4.

(G) Outer beam 11 and inner beam 12
Since the ribs 13a are arranged at both ends of the outer mast 1
The mounting part with can be reinforced. That is, the welding strength at the mounting portion can be increased. In this way, the strength of the tilt beam 4 at both ends can be increased, and the strength of the tilt beam 4 as a whole can be further improved. Further, as described above, the rib 13a is fixed to both ends (end plate portions 11b and 12b) of the tilt beam 4, and the rib 13b is fixed to the center portion (middle plate portions 11a and 12a) of the tilt beam 4, respectively. The strength of each part can be improved in a well-balanced manner. Then, the strength of the tilt beam 4 as a whole can be improved. In this case, stress concentration due to various forces occurs at both ends of the tilt beam 4, but by providing the ribs 13a to increase the strength on both ends, it is possible to sufficiently withstand the stress concentration. Is.
Further, by increasing the strength by using the ribs 13a and 13b, it is possible to easily and surely increase the strength of the tilt beam 4 while maintaining a degree of freedom in selecting a position for arranging various cargo handling equipment in the arrangement space. Is possible.

(H) Outer beam 11 and inner beam 12
Of the ribs 13a, 1 between the beams 11 and 12
By disposing 3b or the like, the strength of the tilt beam 4 can be easily improved, and the cost can be reduced as compared with the case of increasing the strength of the beam 32 by increasing the plate thickness as in the case of the single beam 32. It can be reduced.

The present invention is not limited to the above-mentioned embodiment, and can be implemented as follows with appropriate changes without departing from the spirit of the invention. (1) In the above embodiment, the outer beam 11 may be fixed to the side surface 1a of the outer mast 1 as shown in FIG. In this case, the bonding surface of the outer beam 11 becomes wider, and the outer beam 11 can be more reliably fixed to the outer mast 1.

(2) In the above embodiment, as shown in FIG. 5, the inner beam 12 is replaced by the middle plate portion 11 of the outer beam 11.
You may fix to a. In this case, even if the inner beam 12 cannot be fixed to the outer mast 1 due to the arrangement position of the cargo handling equipment in the arrangement space D, the strength of the tilt beam 4 is fixed by fixing the inner mast 12 to the outer beam 11. Can be increased.

(3) In the above-described embodiment, when the tilt plate 21 in which the tilt bracket 22 is welded is welded to the outer mast 1 and the tilt cylinder 3 is connected to the tilt bracket 22, as shown in FIG. It is also possible to fix the inner beams 11 and 12 to the tilt plate 21. In this case, the outer mast 1
The arrangement space D can be further expanded as compared with the case where the outer and inner beams 11 and 12 are attached.

(4) In the above embodiment, a hollow pipe having a quadrangular outer shape may be used. In this pipe, the rear surface corresponds to the outer beam, the front surface corresponds to the inner beam, and the upper and lower surfaces correspond to the connecting member. Then, for example, a notch is provided in a portion corresponding to the lift cylinders 14 located on the left and right to avoid the lift cylinder. It is also possible to use a cylindrical pipe.

(5) In the above embodiment, the inner beam 12 need not be a thin plate. That is, the strength of the tilt beam 4 can be further increased by using, as the inner beam, a plate that is as thick as possible to avoid various cargo handling equipment in the arrangement space D.

The technical ideas that can be understood from the above-described embodiment will be described below along with their effects. (1) In the invention described in claim 3, the outer beam 11 is thinner than the conventional tilt beam (single beam) 32, and the outer surface 11c of the outer beam 11 is mounted at the outer surface of the single beam 32. Tilt beam that is almost the same position as. According to this tilt beam, the single beam 32
The arrangement space D can be widened by the difference in thickness between the outer beam 11 and the outer beam 11.

[0047]

As described in detail above, according to the first aspect of the invention, the inner beam is attached so as to avoid the cargo handling equipment in the arrangement space, so that the positions where various cargo handling equipment are arranged in the arrangement space. As the degree of freedom in selecting
The strength of the tilt beam can be improved by connecting the outer beam and the inner beam.

According to the second aspect of the invention, the tilt beam can be easily reinforced by connecting the outer beam and the inner beam with the ribs. According to the invention of claim 3, since the outer beam is formed in a U shape,
The arrangement space can be formed wide.

According to the fourth aspect of the invention, the lift cylinder can be easily avoided by bending the inner beam. According to the invention of claim 5, the intensity of the tilt beam can be further increased by disposing the rib in the wide portion of the inner beam.

According to the sixth aspect of the invention, since the wide part of the inner beam is parallel to the outer beam, the range of the wide part can be made as long as possible and the intensity of the tilt beam can be improved.

According to the seventh aspect of the invention, since the ribs fixed to the outer mast are arranged between the tips of the outer and inner beams, the tilt beam strength can be further increased.

[Brief description of drawings]

FIG. 1 is a front view showing an outer mast and the like provided at a front portion of a forklift.

FIG. 2 is a side view showing an outer mast and the like.

FIG. 3 is a plan view showing an arrangement space in which various cargo handling devices are arranged.

FIG. 4 is a sectional view showing the arrangement of tilt beams in another example.

FIG. 5 is a cross-sectional view showing the arrangement of tilt beams in another example.

FIG. 6 is a cross-sectional view showing the arrangement of tilt beams in another example.

FIG. 7 is a plan view showing a conventional tilt beam arrangement space.

FIG. 8 is a perspective view showing a conventional tilt beam.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Outer mast, 4 ... Tilt beam, 11 ... Outer beam, 12 ... Inner beam, 12e ... Convex part as a wide part, 13a, 13b ... Rib as a connecting member, 14 ... Lift cylinder as a cargo handling device.

Claims (7)

[Claims] 1. An outer beam having a pair of outer mast arranged on both left and right sides of a forklift so as to suspend the outer mast, and a tip portion fixed to a part of an outer surface of each outer mast, and the outer mast and the outer beam. A tilt beam comprising an inner beam arranged in the surrounding space so as to avoid cargo handling equipment in the surrounding space, and a connecting member for connecting the outer beam and the inner beam to each other. 2. The tilt beam according to claim 1, wherein the connecting member is a rib arranged between the outer beam and the inner beam. 3. The tilt beam according to claim 1, wherein the outer beam is bent in a U shape and is fixed so as to be convex toward the rear of the outer mast. 4. A lift cylinder for raising and lowering a fork as a cargo handling device is disposed on both left and right sides of the arrangement space, and the inner beam is bent and formed so as to avoid the lift cylinder. Tilt beam. 5. A wide portion is formed in the inner beam so as to widen a space between the inner beam and the outer beam, and a rib is arranged between the wide portion and the outer beam. The tilt beam described in 4. 6. The tilt beam according to claim 5, wherein the wide portion of the inner beam is parallel to the outer beam. 7. The tilt beam according to claim 2, wherein ribs fixed to the outer mast are provided between both ends of the outer beam and the inner beam.