JPH10120387A - Forklift truck mast device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To remarkably reduce the dimension of a right and a left masts in the car-width direction by overlapping an outside mast and an inside mast in right and left and a soft cylinder with each other in the car-width direction. SOLUTION: A web 18 of an outer mast 2 and a cylinder tube 20 of a soft cylinder 1 are integrally formed with each other so as to be overlapped with each other at an intermediate position of the web 18. An inner mast 3 having a H-shaped cross section is guided for support by the outer mast 2 through a liner 24 so as to be overlapped with the cylinder tube 20 in the car-width direction, and the dimension W in the car-width direction can be thereby reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mast device for a forklift truck, and more particularly, to a mast device capable of securing a wider field of view for an operator by changing a relative positional relationship between an outer mast, an inner mast, and a lift cylinder. About.

[0002]

2. Description of the Related Art Japanese Unexamined Utility Model Publication No. Sho 59-123096 and Japanese Utility Model Laid-Open Publication No. Sho 62-1 are so-called wide-view masts having improved forward visibility for an operator.
There is one described in JP-A-32099. In these conventional mast devices, for example, as shown in FIG. 6, a pair of left and right lift cylinders 101 for raising and lowering the inner mast is disposed behind the left and right outer masts 102, and the finger bar (carriage) 103 is also independently raised and lowered. A pair of left and right free lift cylinders 104 are arranged behind the left and right inner masts 105 for the purpose.

[0003] In such a conventional mast device, compared with a type in which a single free-lift cylinder having a relatively large diameter is disposed in the middle of the left and right masts, a device that hinders the view at the center of the mast device. Although the front view of the operator from the driver's seat is improved due to the elimination, the reduction of the width dimension W of the mast itself in the vehicle width direction is naturally limited, leaving room for further improvement of the front view.

On the other hand, for the purpose of reducing the number of components and weight of the mast device, for example, Japanese Patent Application Laid-Open No. 57-1756.
As described in JP-A-99-99, an outer mast 102 as shown in FIG. 6 and a cylinder tube of a lift cylinder 101 are integrally formed, but in this type, an outer mast is provided on an outer surface of the outer mast. The hollow cylinder tube-equivalent portion is merely integrated in advance so as to be circumscribed, and there is a problem that the width W described above cannot be reduced.

The present invention has been made in view of the above-mentioned problems, and is based on a premise that a structure in which an outer mast and a cylinder tube of a lift cylinder are previously formed integrally is provided.
It is an object of the present invention to provide a structure capable of further reducing the width dimension (dimension in the vehicle width direction) of each of the left and right masts.

[0006]

According to the first aspect of the present invention, the outer mast and the lift cylinder are overlapped with each other in the vehicle width direction, and the lift cylinder is positioned at an intermediate portion of the outer mast in the front-rear dimension. And the inner mast is slidably guided and supported via the liner with respect to the outer mast so that the cylinder tube and the inner mast overlap each other in the vehicle width direction. It is characterized by.

According to a second aspect of the present invention, in the first aspect of the invention, the outer mast has a slide guide surface in front of and behind the cylinder tube of the lift cylinder. The inner mast is guided and supported by the guide surface.

According to a third aspect of the present invention, the slide guide surface of the outer mast in the second aspect of the invention is formed as an inner angled shape, and the inner mast is formed by the inner angled slide guide surface. It is guided and supported.

According to a fourth aspect of the present invention, the maximum dimension of the outer mast in the longitudinal direction of the vehicle and the maximum dimension of the inner mast in the longitudinal direction of the vehicle are both set to the same size. It is characterized by.

According to a fifth aspect of the present invention, the slide guide surface of the outer mast in the second aspect of the invention is formed as an outer angle-shaped slide guide surface, and the inner mast is formed by the outer angle-shaped slide guide surface. It is guided and supported.

According to a sixth aspect of the present invention, the outer mast of the second aspect is provided with a vertical first slide guide along the longitudinal direction of the vehicle body, with the cylinder tube of the lift cylinder interposed therebetween. And a groove-shaped second slide guide surface having a bottom surface parallel to the first slide guide surface is formed on the other side, and the first slide is formed on the inner mast. A vertical wall portion guided on the guide surface is formed, and a rib fitted and guided on the second slide guide surface is formed so as to protrude.

Therefore, according to the first aspect of the present invention,
The outer mast, the cylinder tube of the lift cylinder integrated with the outer mast, and the inner mast overlap each other in the vehicle width direction, and the dimensions of the left and right masts in the vehicle width direction are reduced.

And, as in the invention according to claim 2,
Since the inner mast is guided by two slide guide surfaces set before and after the outer mast with the cylinder tube interposed therebetween, the inner mast can be smoothly moved up and down with respect to the outer mast.

In particular, the inner mast is guided and supported by the outer angled or inner angled slide guide surface on the outer mast side as in the third, fourth and fifth aspects of the present invention. The position regulation of the inner mast in the vehicle width direction and the position regulation in the vehicle front-rear direction are performed.

Further, according to the invention described in claim 6, in the first aspect,
The first slide guide surface has a function to regulate the position of the inner mast in the vehicle width direction and the vehicle front-rear direction, while the first slide guide surface has a function to regulate the position in the vehicle width direction. Claims 3 and 4,
In the same manner as described in 5, the position of the inner mast with respect to the outer mast in the vehicle width direction and the position in the vehicle front-rear direction are restricted.

[0016]

According to the first aspect of the invention, the left and right outer masts, the inner mast, and the lift cylinder overlap each other in the vehicle width direction.
The size of the left and right masts in the vehicle width direction can be greatly reduced, and the area that obstructs the operator's front view is reduced accordingly, so that the operator's front view can be secured wider. In addition to improving the workability of cargo handling work, the lift cylinder is formed integrally with the outer mast in the middle part of the front-rear direction dimension, so the lift cylinders are located behind the left and right masts This has the effect of reducing the size of the front overhang, which is the dimension from the front axle to the finger bar, as compared with the conventional type.

According to the second aspect of the present invention, the inner mast is guided by the slide guide surface set before and after the cylinder tube of the lift cylinder among the outer masts. In addition to the same effect as the invention described in (1), there is an effect that the raising / lowering operation of the inner mast is performed more smoothly.

According to the third aspect of the present invention, since the slide guide surface of the outer mast is formed as an inner angle, the position of the inner mast with respect to the outer mast in the vehicle width direction and the vehicle front-rear direction. The regulation is reliably performed, and there is an effect that the elevating operation of the inner mast is performed more smoothly.

According to the fourth aspect of the present invention, since the slide guide surface of the outer mast is formed as an outer angle, in addition to the same effect as the second and third aspects, By reducing the size of the outer mast and the inner mast itself in the vehicle longitudinal direction, the front overhang can be further reduced. In particular, as in the invention of claim 5, the dimensions of the outer mast and the inner mast in the vehicle longitudinal direction are reduced. By arranging them, there is an effect that the size and thus the front overhang can be further reduced.

Further, according to the invention described in claim 6,
The first slide guide surface on the outer mast side regulates the vehicle width direction position of the inner mast, while the second slide guide surface regulates the vehicle width direction position of the inner mast and the vehicle longitudinal direction position. Therefore, in addition to the same effect as the invention described in the second aspect, the size of the outer mast in the vehicle longitudinal direction and the front overhang can be further reduced by sharing the functions of the first and second slide guide surfaces. effective.

[0021]

1 and 2 are views showing a typical embodiment of the present invention, showing an example of a two-stage mast.

As shown in FIGS. 1 and 2, the lift cylinder 1
Inner mast 3 inside the left and right outer masts 2
Are arranged so as to be able to move up and down. Left and right outer mast 2,
The two inner masts 3 are mutually connected via an upper beam 4, a cross beam 5 and a mast support 6, while the left and right inner masts 3 are mutually connected via a mast head 7 and a tie beam 8. A lift bracket 9 is provided inside each inner mast 3 so as to be able to move up and down, and a finger bar (carriage) 10 is fixed to the lift bracket 9. A fork (not shown) is attached to the finger bar 10. Be attached.

A pair of chain wheels 12 are supported on the mast head 7 via a chain wheel bracket 11, and a lift chain 13 is wound around each chain wheel 12. Each lift chain 13
Is connected to the cross beam 5 and the other end is connected to the lift bracket 9.

Since the piston rod 14 of the lift cylinder 1 is connected to the inner mast 3 via the bracket 15 as shown in FIG. 2, when the lift cylinder 1 is extended from the state shown in FIG.
As a result, the chain bar 12 integrally moves up, and as a result, the finger bar 10 moves up along the inner mast 3 at twice the speed of the lift cylinder 1. Incidentally, reference numeral 16 in FIG.
Is a mast support bracket.

The left and right outer masts 2 described above are similar to those shown in FIG.
As shown in FIG. 5, although the web 18 and the flange portion 19 bent back and forth are formed in a substantially U-shaped cross section, a circle which is a main element of the lift cylinder 1 is provided at an intermediate portion of the web 18. An annular cylinder tube 20 is integrally formed in advance, and the center of the cylinder tube 20 and the center of the web 18 are aligned.
Note that the two centers do not necessarily need to coincide.

On the other hand, the left and right inner masts 3 disposed inside the left and right outer masts 2 are formed as a substantially H-shaped cross section by the web 21 and the front and rear flange portions 22. When one end of the portion 22 enters the inside of the flange portion 19 on the outer mast 2 side, the inner mast 3 is guided so as to be able to move up and down with respect to the outer mast 2.

That is, the dimensions of the outer mast 2 and the cylinder tube 20 integral therewith overlap each other in the vehicle width direction, and at the same time, the dimensions of the cylinder tube 20 and the inner mast 3 also overlap each other in the vehicle width direction. Since the outer mast 2 and the lift cylinder 1 and the inner mast 3 partially overlap each other in the vehicle width direction as a result, the width dimension W of the left and right masts is reduced.

An inner corner formed by the web 18 of the outer mast 2 and the front and rear flanges 19 is set as an inner angled slide guide surface 23 for the inner mast 3. Inner mast 3 through angled liner 24
The side flange portion 22 is guided so as to be able to move up and down, and the position of the inner mast 3 with respect to the outer mast 2 in the vehicle width direction and the vehicle front-rear direction is regulated. This allows
The left and right masts are formed in a front-rear symmetric shape with respect to a plane passing through the axis of the left and right lift cylinders 1 and 1 as a center of symmetry in plan view.

Therefore, according to the present embodiment, since there is no lift cylinder behind the left and right masts,
Not only can the front overhang, which is the distance from the front axle to the finger bar 10, be reduced, but also the space behind the left and right masts can be effectively used as an arrangement space for chains, pipes or attachment pipes, for example. , Less space constraints,
By arranging a chain or the like behind the mast, the visibility is further improved.

Moreover, as shown in FIG. 1, by reducing the width W of the left and right masts in the vehicle width direction, it is possible to minimize the area that obstructs the operator's view from the driver's seat. As a result, it is possible to secure a wider front view of the operator, and it is possible to improve workability and safety during cargo handling.

FIG. 3 is a view showing a second embodiment of the present invention. The outer mast 32 and the cylinder tube 30 of the lift cylinder 31 are integrally formed in advance in common with the one shown in FIG. However, the flange portion 36 is bent only in the outer mast 32 on the rear side of the cylinder tube 30 so that the U-shaped groove-shaped second slide guide surface 3 is formed.
On the other hand, it is different from that shown in FIG. 1 in that a flat first slide guide surface 35 is formed on the front side of the cylinder tube 30 on the other hand.

On the other hand, the inner mast 33 is basically formed in a substantially U-shaped cross section by a web 37 and a flange portion 38 formed to be bent before and after the web 37. A rib 39 pointing in the direction is formed so as to protrude.

The web 37, which is the vertical wall surface of the inner mast 33, is guided to the first guide support surface 35 on the outer mast 32 side via the liner 40, while the rib 39 is guided via the liner 41 having a U-shaped cross section. Slide guide surface 34
The guide is supported.

According to this embodiment, the outer mast 32, the inner mast 33, and the lift cylinder 31 are overlapped with each other in the vehicle width direction, while the first slide guide surface 35 of the outer mast 32 is used as described above. It regulates the position of the inner mast 33 in the vehicle width direction,
And the inner mast 3 by the second slide guide surface 34
3, the position L of the outer mast 32 in the vehicle longitudinal direction can be reduced at the same time, as is apparent from comparison with FIG. Become.

FIG. 4 is a view showing a third embodiment of the present invention. As is apparent from comparison with FIG.
2 is a shape of only the web 53 without a flange portion, while a portion of the cylinder tube 50 of the lift cylinder 51 on the inner mast 54 side is a prismatic shape, and an outer angle is formed between the prismatic portion 55 and the web 53. A slide guide surface 56 is formed.

On the other hand, since the inner mast 54 is formed to have an H-shaped cross section by the web 57 and the flange 53 similarly to the inner mast shown in FIG. By guiding and supporting one end of the flange portion 58 of the inner mast 54 via 59, the position of the inner mast 54 with respect to the outer mast 52 in the vehicle width direction and the vehicle front-rear direction is regulated. The outer mast 52 and the inner mast 54 have the same maximum dimension L in the vehicle front-rear direction.

In this embodiment, basically, similarly to the first embodiment shown in FIG. 1, the front overhang can be reduced and the dimension W of the left and right masts in the vehicle direction can be reduced. In particular, since the outer mast 52 does not have the flange portion shown in FIG.
And the inner mast 54 both have a dimension L in the vehicle longitudinal direction.
Can be further reduced, and as a result, the foot overhang can be further reduced.

FIG. 5 is a view showing a fourth embodiment of the present invention, and shows an example of a three-stage mast.

In this embodiment, the lift cylinder 61
The outer mast 62 integrally formed with the cylinder tube 60 has a flange portion 64 integrally bent before and after a web 63, and a portion of the cylinder tube 60 on the middle mast 65 side is formed in a prismatic shape. An outer angle-shaped slide guide surface 67 is formed between the prism portion 66 and the web 63.

On the other hand, the middle mast 65 has a flange portion 69 integrally formed in front and rear of a web 68, and a rib 70 protrudingly formed on the back side thereof. The rib 70 is formed by the cylinder tube 60 and the outer mast. It is guided and supported via an outer angled liner 71 so as to overlap with 52.

Further, the inner mast 72 is formed in substantially the same shape as the middle mast 65, and is guided and supported by the middle mast 65 via an outer angle liner 73. And outer mast 62 and middle mast 6
5 and the inner mast 72 have the same maximum size in the vehicle front-rear direction.

This embodiment has the same advantages as the first to third embodiments, even though the mast is a three-stage mast.

Here, the first to third embodiments show the case of a two-stage mast, and the fourth embodiment shows the case of a three-stage mast. It is also possible to use a three-stage mast in the form, and it is also possible to abolish the inner mast 72 of the fourth embodiment and use a two-stage mast.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention, and FIG.
Sectional drawing which follows the -A line.

FIG. 2 is a perspective view of a mast device showing the first embodiment of the present invention.

FIG. 3 is an essential part cross-sectional view of a mast device showing a second embodiment of the present invention.

FIG. 4 is a sectional view of a main part of a mast device according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a main part of a mast device showing a fourth embodiment of the present invention.

FIG. 6 is an explanatory plan view showing an example of a conventional mast device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Lift cylinder 2 ... Outer mast 3 ... Inner mast 20 ... Cylinder tube 23 ... Slide guide surface 24 ... Liner 30 ... Cylinder tube 31 ... Lift cylinder 32 ... Outer mast 33 ... Inner mast 34 ... Second slide guide surface 35 ... First slide Guide surface 37 ... Web (vertical wall portion) 39 ... Rib 40 ... Liner 41 ... Liner 50 ... Cylinder tube 51 ... Lift cylinder 52 ... Outer mast 54 ... Inner mast 56 ... Slide guide surface 59 ... Liner 60 ... Cylinder tube 61 ... Lift cylinder 62 ... Outer mast (outside mast) 65 ... Middle mast (inside mast) 67 ... Slide guide surface 70 ... Rib 71 ... Liner

Claims (6)

[Claims] An outer mast and a cylinder tube of a lift cylinder are integrally formed such that the lift cylinder is located at an intermediate portion of the outer mast in the front-rear direction and overlaps with each other in a vehicle width direction. A mast device for a forklift truck, wherein the inner mast is slidably guided and supported via a liner with respect to the outer mast so that the inner mast and the inner mast overlap each other in the vehicle width direction. 2. The outer mast has a slide guide surface in front of and behind the cylinder tube of the lift cylinder, and the inner mast is guided and supported by the two front and rear slide guide surfaces. The forklift truck mast device according to claim 1. 3. The slide guide surface of the outer mast is formed as an inner angled one, and the inner mast is guided and supported by the inner angled slide guide surface. Forklift truck mast equipment. 4. A mast device for a forklift truck according to claim 3, wherein the maximum size of the outer mast in the vehicle front-rear direction and the maximum size of the inner mast in the vehicle front-rear direction are the same. . 5. The slide guide surface of the outer mast is formed as an outer angled one, and the inner mast is guided and supported by the outer angled slide guide surface. Forklift truck mast equipment. 6. A vertical first slide guide surface extending in the vehicle longitudinal direction is formed on one of the front and rear sides of a cylinder tube of a lift cylinder on the outer mast, and the other is formed on the other side. A second groove-shaped slide guide surface having a bottom surface parallel to the first slide guide surface is formed, and a vertical wall portion guided by the first slide guide surface is formed on the inner mast. 3. The mast device for a forklift truck according to claim 2, wherein a rib which is fitted and guided on the second slide guide surface is formed so as to protrude.