JP3496474B2 - Reach type forklift reach cylinder mounting structure - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reach cylinder mounting structure provided in a reach type forklift.

[0002]

2. Description of the Related Art FIG. 7 is a side view showing a general reach type forklift truck. Outer masts 2 standing upright on both sides in the vehicle width direction are provided on the front side of a forklift body 1, and a lift cylinder is provided inside the outer mast 2. An inner mast 4 is provided that moves up and down along the outer mast 2 by driving the outer mast 3, and a fork 5 is supported by the inner mast 4.

A reach cylinder 10 is provided between the forklift body 1 and the outer mast 2.
The reach cylinder 10 includes a cylinder tube 14 attached to the forklift main body 1 via a mounting bracket 12, and a piston rod 16 supported by the cylinder tube 14 so as to be able to move forward and backward and having an outer mast 2 fixed to a front protruding end thereof. have. By moving the piston rod 16 forward and backward with respect to the cylinder tube 14, the outer mast 2 moves in the vehicle front-rear direction with respect to the forklift body 1.

That is, in the reach type forklift, the outer mast 2 which supports the inner mast 4 and the fork 5 so as to be able to move up and down is movable in the front-rear direction with respect to the forklift main body 1, so that the cargo handling and transportation can be performed especially in a narrow road. Suitable for work.

Reference numeral 6 denotes a pair of left and right straddle arms for guiding the movement of the outer mast 2 in the front-rear direction, 7 at least one driven wheel near the front end of each straddle arm 6, and 8 a lower portion of the forklift body 1. It is one drive wheel arranged at the rear in the center in the vehicle width direction.

8 and 9 show an example of a structure for mounting the reach cylinder 10 in such a reach-type forklift.

FIG. 8 shows a so-called trunnion type cylinder mounting structure. A pair of pivot pins 18 are provided on the outer periphery of the cylinder tube 14 at a position slightly opposite to the rod from the center in the axial direction so as to project in the directions orthogonal to the axis and in the horizontal direction in mutually opposite directions. Each pivot pin 18
Are sandwiched by a pair of upper and lower mounting brackets 20 (corresponding to the mounting brackets 12 in FIG. 7) fixed to the forklift body 1 (FIG. 7). That is, the reach cylinder 10 is attached to the forklift main body 1 in a state in which the reach cylinder 10 can slightly swing in the vertical direction about the pivot pin 18 and can slightly move in the horizontal direction.

Further, at the protruding end of the piston rod 16,
A cylindrical boss portion 22 is provided, and inside the boss portion 22, a pin hole 22 extending in the direction perpendicular to the axis and in the horizontal direction is provided.
a is formed. On the other hand, the mast side bracket 24 fixed to the outer mast 2 (FIG. 7) is formed in a substantially U shape, and a pair of pin holes 24a is formed in the opposing wall. The pin 26 is inserted through these pin holes 22a and 24a, and as a result, the outer mast 2 and the reach cylinder 10 are
And are connected so as to be relatively movable in the vertical and horizontal directions.

FIG. 9 shows a so-called clevis type cylinder mounting structure. That is, at the rear end portion of the cylinder tube 14 opposite to the rod side, a cylindrical head side boss portion 28 is formed.
Is formed in the head side boss portion 28, and a pin hole 28a extending in the direction perpendicular to the axis and in the vertical direction is formed. The mounting bracket 30 fixed to the forklift body 1 is provided with a pair of opposing walls 31.
A pin hole 31 a is formed in each opposing wall 31. Then, the pin 32 is inserted into the pin holes 28 a and 31 a with the head-side boss portion 28 fitted between the opposing walls 31 of the mounting bracket 30. As a result, the reach cylinder 10 is
The pin 32 is attached to the forklift main body 1 in a state in which the pin 32 can be slightly swung in the horizontal direction and slightly movable in the vertical direction.

Further, similarly to the trunnion type cylinder shown in FIG. 8, a cylindrical boss portion 22 is integrally formed at the projecting end of the piston rod 16, and the boss portion 22 has an inside in the direction perpendicular to the axis. And a pin hole 22a extending in the vertical direction
Are formed. On the other hand, pin holes 24a are formed in the mast side bracket 24 fixed to the outer mast 2, and pins 26 are inserted into these pin holes 22a, 24a. As a result, the outer mast 2 and the reach cylinder 10 are connected so as to be relatively movable in the vertical and horizontal directions.

That is, the reach cylinder 10 is attached so as to be slightly movable vertically and horizontally in consideration of dimensional errors and the like.

[0012]

Reach cylinder 10
7, the axial distance L from the protruding end of the piston rod 16 to which the outer mast 2 is attached to the fulcrum portion to be attached to the forklift body 1 via the attachment bracket 12 is long, so that, for example, of the fork 5 When the toes collide with an obstacle such as a wall, buckling may occur.

In particular, the reach cylinder 10 is fully stroked, that is, the piston rod 16 is projected most forward, and the cylinder tube 14 as shown in FIG.
When the clevis-type mounting structure in which the end portion on the side opposite to the rod is mounted to the forklift body 1, the axial distance L is further increased, and buckling is likely to occur.

An object of the present invention is to effectively improve the buckling strength without impairing the assembling property and the like.

[0015]

Therefore, in the invention of claims 1 to 5, a cylinder tube attached to the forklift body via a mounting bracket, and a cylinder tube supported so as to be movable back and forth on the cylinder tube, and an outer mast at a front protruding end thereof. In a mounting structure for a reach cylinder that includes a piston rod fixed to, a cylinder support is provided near the outer circumference of the cylinder tube on the rod side of the mounting bracket.
A predetermined gap is set between at least the left and right sides of the vehicle in the vehicle width direction .

For example, when the toe of a fork attached to the outer mast side comes into contact with an obstacle such as a wall, the cylinder tube comes into contact with and engages with the cylinder support portion immediately before the reach cylinder buckles, and this contact occurs. Since the portion serves as a fulcrum for the protruding end of the piston rod, the axial distance for buckling is substantially shortened, and the buckling strength can be effectively improved.

Further, in a normal state, since a predetermined gap is set between the cylinder support portion and the outer circumference of the cylinder tube, the dimensional accuracy of the cylinder support portion and the reach cylinder is not excessively required, and the dimensional accuracy thereof is not required. Assemblability is not impaired.

When the reach cylinder is a clevis type cylinder in which the end of the cylinder tube on the side opposite to the rod is swingably supported by the forklift body, the axis of the reach cylinder against buckling can be obtained. Although the directional distance is even longer, it is disadvantageous in terms of buckling strength.However, since the cylinder support is located near the end of the cylinder tube on the rod side, the axial direction for buckling is approximately the entire length of the cylinder tube. The distance can be shortened and the buckling strength can be improved more effectively.

Specifically, when the reach cylinder is fully stroked, the cylinder support portion is located substantially at the center in the axial direction of the reach cylinder, and the axial distance for buckling is reduced to approximately half.

According to the third aspect of the invention, there is further provided an adjusting means for adjusting the gap width between the cylinder supporting portion and the outer circumference of the cylinder tube.

Therefore, dimensional accuracy is not required excessively, and the gap width can be adjusted appropriately for each product.

According to the fourth aspect of the present invention, the base frame of the forklift body extends below the cylinder tube, and the cylinder support portion is provided with a predetermined gap on the left and right sides of the cylinder tube in the vehicle width direction. In this state, the pair of support brackets are erected on the base frame.

In this case, the number of parts of the cylinder supporting portion can be small and the structure can be simplified.

In the invention of claim 5, the base frame of the forklift main body extends below the cylinder tube, and the cylinder support portion includes an auxiliary plate joined to a front side surface of the base frame, and the auxiliary plate. It has a substantially U-shaped U-shaped bracket fixed to the plate with bolts, and a predetermined gap is set between the inner circumference of the U-shaped bracket and the outer circumference of the cylinder tube.

In this case, since it is not necessary to process the upper surface of the base frame, the base frame can be shared by a product to which the mounting structure of the present invention is applied and a product to which the mounting structure of the present invention is not applied, thereby improving the productivity.

[0026]

As described above, according to the present invention, the buckling strength of the reach cylinder can be effectively improved without impairing the assembling property.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described in detail below with reference to the drawings.

1 and 2 show a first embodiment in which the reach cylinder mounting structure according to the present invention is applied to the reach type forklift shown in FIGS. 7 to 9
With respect to the structure shown in (1), redundant description will be omitted as appropriate, and the same reference numerals will be given to the same members.

The reach cylinder 10 shown in FIGS. 1 and 2 is, for example, a clevis type cylinder as shown in FIG.
Cylinder tube 14 attached to the forklift main body 1 via the attachment bracket 30 at the end opposite to the rod
And a piston rod 16 supported by the cylinder tube 14 so as to be able to advance and retreat in the front-rear direction and having the outer mast 2 attached to the front protruding end thereof. A nipple 15 is provided on the outer periphery of the cylinder tube 14 near the rod-side end.

The base frame 9 of the forklift body 1 extends below the cylinder tube 14. The reach cylinder 1 is attached to the front portion of the base frame 9.
A cylinder support portion 40 that supports 0 is attached.

The cylinder support portion 40 is a rectangular plate-shaped horizontal plate 42 joined to the lower surface of the base frame 9.
And a stepped lower surface joined to the upper surface of the horizontal plate 42 and the upper surface of the base frame 9 to stand vertically on the side of the reach cylinder 10 near the rod side end, and the rod of the cylinder tube 14. A U bolt 48 attached to the vertical plate 44 using a double nut 46 and an adjustment bolt 52 attached to the vertical plate 44 using a lock nut 50 are provided so as to cover the outer periphery near the side end portion. ing.

More specifically, U having a threaded portion formed on the outer periphery thereof
The tip ends of both legs of the bolt 48 are inserted into a pair of upper and lower insertion holes 44a formed in the vertical plate 44, and a double nut 46 is screwed from the opposite side. Further, an adjustment bolt 52 having a threaded portion on the outer periphery is screwed into and inserted into a screw hole 44b formed in the vertical plate 44, and a lock nut 50 is screwed to the adjustment bolt 52.

Here, as shown in FIG. 2, the U bolt 4
A predetermined gap D1 is set between the inner circumference of the top portion 48a of 8 and the outer circumference of the cylinder tube 14, and a predetermined gap D2 is set between the tip of the adjusting bolt 52 and the outer circumference of the cylinder tube 14. There is. In other words, the predetermined gaps D1 and D2 are set between the outer circumference of the cylinder tube 14 and the cylinder support portion 40 in the horizontal direction.

That is, the cylinder support portion 40 is located substantially in the center of the reach cylinder 10 in the axial direction when the reach cylinder 10 is fully stroked, that is, when the piston rod 16 is most protruded, and in the horizontal direction perpendicular to the axis. It is not in contact with the outer periphery of the cylinder tube 14.

Further, the widths of the gaps D1 and D2 can be adjusted later. That is, the gap D2 can be easily adjusted by rotating the adjusting bolt 52 and moving it back and forth using a jig (not shown) with the lock nut 50 loosened. In addition, the gap D1 is U by loosening the double nut 46.
It can be adjusted by moving the bolt 48. The gaps D1 and D2 are set to have the same length, for example, about 0.25 to 5.0 mm.

According to the structure of the embodiment as described above, for example, when the toe of the fork 5 collides with an obstacle such as a wall, the U bolt of the cylinder support portion 40 immediately before the reach cylinder 10 buckles. 48 Inner circumference or adjustment bolt 5
Since the two tips contact and engage with the outer circumference of the cylinder tube 14, this contact portion serves as a fulcrum for the projecting end of the piston rod 16 and supports the cylinder tube 14. As a result, the axial distance for buckling is shortened, and the buckling strength can be effectively improved. For example, when the piston rod 16 is most protruded, the axial distance for buckling is reduced to about half.

Further, since the clearances D1 and D2 are set between the cylinder support portion 40 and the outer circumference of the cylinder tube 14, the welding accuracy of the cylinder support portion 40 is not required excessively, and the reach cylinder 10 and the reach cylinder are not required. The assemblability of 10 is not hindered.

In addition, since the widths of the gaps D1 and D2 can be easily adjusted later, the dimensional accuracy is not excessively required, and the gap width can be appropriately adjusted for each product.

FIG. 3 shows a second embodiment of the present invention.
The reach cylinder 10 is a clevis type cylinder as shown in FIG. 9, and the base frame 9 of the forklift body 1 extends below the reach cylinder 10. The base frame 9 is provided with a pair of columnar support pins (brackets) 56 that form a cylinder support portion. The support pin 56 is the cylinder tube 14
A predetermined gap D3 is provided between the outer circumference of the cylinder tube 14 and the outer circumference of the cylinder tube 14. Also,
The support pin 56 is provided near the front end of the base frame 9 and is located near the rod-side end of the cylinder tube 14.

FIG. 4 shows a third embodiment of the present invention, in which a pair of rectangular plate-shaped support brackets 58 are fixed to the base frame 9 instead of the support pins 56 of FIG. . The support bracket 58 is the support pin 56.
Similar to the above, it is located near the end of the cylinder tube 14 on the rod side, and has a predetermined gap D
4 is set.

In the second and third embodiments, the buckling of the reach cylinder 10 can be effectively suppressed in the same manner as in the first embodiment described above, and the cylinder support portion has a pair of support pins 56. Alternatively, since the support bracket 58 is used, the number of parts is small and the structure is simplified.

5 and 6 show a fourth embodiment of the present invention. In this embodiment, the front side surface 9 of the base frame 9 is
An auxiliary plate 60 is fixed to a by welding, and a flange portion 62b of a U-shaped bracket 62 that covers the outer circumference of the cylinder tube 14 is fastened and fixed to the upper surface of the auxiliary plate 60 with a pair of bolts 64. Then, a predetermined gap D5 is set between the inner circumference of the substantially U-shaped main body 62a of the U-shaped bracket 62 and the outer circumference of the cylinder tube 14.

In the fourth embodiment, like the first to third embodiments described above, the buckling strength of the reach cylinder 10 can be effectively improved, and the base frame 9 can be used.
Since it is not necessary to process the upper surface side of the base frame 9, the base frame 9 can be shared by the product to which this mounting structure is applied and the product to which this mounting structure is not applied, and the productivity thereof is improved.

The present invention is not limited to the above-described embodiment, but can be applied to a trunnion type cylinder as shown in FIG. 8, for example.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main part of a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a perspective view showing a main part of a second embodiment of the present invention.

FIG. 4 is a perspective view showing a main part of a third embodiment of the present invention.

FIG. 5 is a top view showing a fourth embodiment of the present invention.

6 is a cross-sectional view taken along the line BB of FIG.

FIG. 7 is a side view of the reach type forklift.

FIG. 8 is an exploded perspective view showing a mounting structure of a trunnion type reach cylinder.

FIG. 9 is an exploded perspective view showing a mounting structure for a clevis-type reach cylinder.

[Explanation of symbols]

1 ... Forklift body 2 ... Outer mast 9 ... Base frame 10 ... Reach cylinder 14 ... Cylinder tube 16 ... Piston rod 12, 20, 30 ... Mounting bracket 40 ... Cylinder support 52 ... Adjust bolt (adjusting means) 56 ... Support pin 58 ... Support bracket 60 ... Auxiliary plate 62 ... U-shaped bracket D1-D5 ... Gap

Claims (5)

(57) [Claims] 1. A mounting of a reach cylinder including a cylinder tube mounted on a forklift body via a mounting bracket, and a piston rod movably supported by the cylinder tube and having an outer mast fixed to a front protruding end thereof. In the structure, a cylinder support portion is provided near the outer circumference of the cylinder tube on the rod side of the mounting bracket , and at least both the left and right sides in the vehicle width direction of the cylinder support portion and the outer circumference of the cylinder tube.
A reach cylinder mounting structure for a reach-type forklift, characterized in that a predetermined gap is set between the and . 2. The reach cylinder is a clevis type cylinder in which an end of the cylinder tube on the side opposite to the rod is swingably supported by the forklift body, and the cylinder support is provided near the end of the cylinder tube on the side of the rod. The reach cylinder mounting structure for a reach type forklift according to claim 1, wherein the reach cylinder mounting structure is provided. 3. The reach cylinder mounting structure for a reach type forklift according to claim 1, further comprising adjusting means for adjusting a gap width between the cylinder supporting portion and the outer circumference of the cylinder tube. 4. A base frame of a forklift main body extends below the cylinder tube, and the cylinder support portion is provided with a predetermined gap on both left and right sides of the cylinder tube in the vehicle width direction. The reach cylinder mounting structure for the reach type forklift according to claim 1 or 2, wherein the support brackets are a pair of support brackets that are erected upright. 5. A base frame of the forklift body extends below the cylinder tube, and the cylinder support portion uses an auxiliary plate joined to a front side surface of the base frame and a bolt for the auxiliary plate. And a substantially U-shaped bracket fixed in place.
The reach cylinder mounting structure for a reach type forklift according to claim 1 or 2, wherein a predetermined gap is set between the inner circumference of the V-shaped bracket and the outer circumference of the cylinder tube.