JPH11116193A - Forklift truck mast device - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve visibility by effectively utilizing a dead space and housing a chain or a hydraulic hose between a middle mast and an inner mast. SOLUTION: A three-stage mast which is a full-free mast and is configured as a slide mast has an inner mast 4
A part of the inner mast lift chain 28 and a part of a hydraulic hose 29 connecting the lift cylinder 2 and the free lift cylinder 18 are accommodated in a space 31 formed between the inner mast 3 and the inner mast 3. The outer mast 1 is composed of the mast itself and the cylinder tube 15 of the lift cylinder 2.
Use a ram cylinder type that integrates

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 three-stage type in which a lift cylinder and a free lift cylinder are formed as a free mast and a slide mast and each of a lift cylinder and a free lift cylinder is independent on the left and right. Regarding the structure of the mast.

[0002]

2. Description of the Related Art A so-called wide field of view mast for widening the forward field of view of an operator has been proposed.
And Japanese Unexamined Utility Model Publication No. 62-132099. In these conventional mast devices, for example, as shown in FIG.
01 is arranged behind the left and right outer masts 102 corresponding thereto, and a pair of left and right free lift cylinders 104 for raising and lowering the lift bracket (carriage) 103 alone are arranged behind the left and right inner masts 105. . In the figure, reference numeral 106 denotes a middle mast, and 107 denotes a finger bar.

[0003]

In such a conventional mast device, the mast device is compared with a type in which a single free lift cylinder having a relatively large diameter is disposed between the left and right masts. Although there is nothing obstructing the view in the center, the operator's front view from the driver's seat is improved, but there is no change in the fact that chains and hydraulic piping are attached behind the left and right masts, and furthermore There is still room for improvement in the field of view.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a mast device which further improves the field of view by improving the arrangement of chains and hydraulic piping. Is what you do.

[0005]

According to a first aspect of the present invention, there is provided a three-stage mast in which a lift cylinder and a free lift cylinder are formed as a free mast and a slide mast, and each of a lift cylinder and a free lift cylinder is independent on the left and right. Further, a chain for driving the inner mast is disposed in a space formed between the inner mast and the middle mast.

According to a second aspect of the present invention, a hydraulic hose connected to a free lift cylinder is provided in a space formed between the inner mast and the middle mast according to the first aspect of the invention for driving the inner mast. It is characterized by being arranged with a chain.

A third aspect of the present invention is characterized in that a pair of left and right free lift cylinders according to the first or second aspect of the invention is disposed behind corresponding left and right masts.

According to a fourth aspect of the present invention, the left and right outer masts according to the second aspect of the present invention and the corresponding cylinder tubes of the lift cylinder are formed as a single unit in advance, and the lift cylinder is a ram. It is characterized by being a shaped cylinder.

A fifth aspect of the invention is characterized in that the other end of the hydraulic hose connected to the free lift cylinder according to the fourth aspect of the invention is connected to the upper end of the lift cylinder.

Therefore, according to the first aspect of the present invention,
The chain for driving the lifting and lowering of the inner mast is wound around a chain wheel provided on the upper part of the middle mast, one end of which is connected to the inner mast and the other end thereof is connected to the outer mast. The portion from the chain wheel to the connecting portion between the inner mast and the inner mast is stored in the space formed between the inner mast and the middle mast and is not exposed to the outside.

According to the second aspect of the present invention, a part of the hydraulic hose having substantially the same configuration as the chain winding structure is formed between the inner mast and the middle mast together with the chain. Stored in the department.

According to the third aspect of the present invention, the left and right free lift cylinders and the corresponding left and right masts overlap in the vehicle width direction, and the vehicle widths of the left and right masts including the free lift cylinders are different. Directional dimensions are reduced.

According to the fourth aspect of the present invention, since the left and right outer masts and the lift cylinder are substantially integrally formed, the outer width including the lift cylinders in the vehicle width direction, and consequently, the vehicle width of the left and right masts is reduced. Directional dimensions are reduced.

According to the fifth aspect of the present invention, the lift cylinder itself is a ram-type cylinder, and the other end of the hydraulic hose connected to the free lift cylinder is connected to the upper end of the lift cylinder, and the ram-type cylinder type lift is used. Communicate with the hydraulic chamber of the cylinder. Thus, the hydraulic pressure can be supplied to the free lift cylinder with a simple hose layout.

[0015]

According to the first aspect of the present invention, since the chain for driving the inner mast is arranged in the space formed between the inner mast and the middle mast,
Since at least the part of the chain stored in the space is not exposed to the outside, it is possible to secure a wider field of view in front of the operator and to clear the field of view.

In addition, since a part of the chain is stored in the space between the inner mast and the middle mast as described above, the chain wheel around which the chain is wound is overlaid on the mast itself in the vehicle longitudinal direction. Since it is possible to wrap, the front overhang, which is the dimension from the front axle to the lift bracket, can be made smaller by reducing the front-rear dimension of the mast including the chain and the chain wheel.

In particular, according to the second aspect of the present invention, even a part of the hydraulic hose together with the chain is disposed in the space between the inner mast and the middle mast. The effect of clearing is more remarkable.

According to the third aspect of the invention, since the left and right independent free lift cylinders are arranged behind the corresponding left and right masts, the size of each of the left and right masts in the vehicle width direction can be reduced. As a result, this also has the effect of contributing to widening the front view.

According to the fourth aspect of the present invention, since the left and right outer masts and the corresponding ram-type cylinder type lift cylinders are substantially integrated, the vehicle width of the left and right masts including the lift cylinders is provided. The size in the direction can be reduced, and there is an effect that a wider field of view can be realized.

According to the fifth aspect of the present invention, since the other end of the hydraulic hose connected to the free lift cylinder is connected to the upper end of the ram-type cylinder type lift cylinder, the hydraulic hose is attached to the free lift cylinder. The piping system is simpler, which has the effect of clearing the field of view.

[0021]

1 to 6 show a preferred embodiment of the present invention, in which left and right outer masts 1 and corresponding left and right lift cylinders 2 are substantially integrated, Moreover, an example in which the lift cylinder 2 is a ram type cylinder type is shown. FIG. 1 is a view corresponding to the plan view of FIG. 2, but only main components are shown in order to avoid complication.

As shown in FIGS. 1-4, the lift cylinder 1
Middle mast 3 inside left and right outer masts 2
The inner mast 4 is arranged inside the middle mast 3 so as to be able to move up and down. The left and right outer masts 2, 2 are upper beams 5,
The right and left middle masts 3 are connected to each other via a cross beam 6 and a mast support 7, and also via an upper beam 9 and a lower beam (not shown).

On the other hand, the left and right inner masts 4 are mutually connected via a mast head 10 and a lower beam 11. A lift bracket 12 is provided inside each inner mast 4 so as to be able to move up and down, and a finger bar (carriage) 13 is attached to the lift bracket 12.
Is fixed, and a fork (not shown) is attached to the finger bar 13. Then, as shown in FIG. 2, the rod (ram or plunger) 14 of the lift cylinder 2
Is connected to the middle mast 3.

As shown in FIGS. 2 to 4, the height of each mast is set higher by a predetermined amount in the middle mast 3 than in the outer mast 1, and
The inner mast 4 is set higher than the inner mast 4 by a predetermined amount a, and the chain wheel 26 and the hydraulic pressure of the inner mast lift chain 28 are adjusted so as to be within the height difference a between the middle mast 3 and the inner mast 4 as described later. A wheel 27 for a hose 29 is arranged.

As shown in FIG. 1, the left and right outer masts 1 are formed in a substantially U-shaped cross section by a web 1a and front and rear flange portions 1b.
An annular cylinder tube 15 which is a main element of the lift cylinder 2 is integrally formed in advance at an intermediate portion of a. On the other hand, the middle mast 3 disposed inside the left and right outer masts 1 is formed to have a substantially U-shaped cross section similarly to the outer mast 1, but a pair of front and rear ribs 3b project from the back side of the web 3a. The rib 3b is connected to the outer mast 1 via a liner 16 having an L-shaped cross section.
The middle mast 3 is guided so as to be able to move up and down with respect to the outer mast 1 by entering the inside of the side flange portion 1b. This slide guide structure is the same for the relationship between the middle mast 3 and the inner mast 4, and 17 is a liner.

With the above structure, the masts of the outer mast 1, the middle mast 3, and the inner mast 4 are completely overlapped in the front-rear dimension of the outer mast 1 without offsetting each other in the front-rear direction. Not only between the middle mast 3 and the inner mast 4 but also between the outer mast 1 and the cylinder tube 15 of the lift cylinder 2 integral therewith in the vehicle width direction, the cylinder tube 15 and the middle mast 3 The dimensions overlap each other in the vehicle width direction, and as a result, the outer mast 1,
The width of the left and right masts formed by the middle mast 3, the inner mast 4, and the lift cylinder 12 in the vehicle width direction is reduced.

On the lower beam 11 connecting the left and right inner masts 4, left and right free lift cylinders 18 of a ram type cylinder type or a single-acting piston type are set up so as to be located behind the respective inner masts 4. A chain wheel 19 is attached to the tip of the rod of each free lift cylinder 18.
A lift chain 20 is wound around each chain wheel 19, and one end of each lift chain 20 is connected to a chain anchor bracket 21 on the cylinder tube side of the free lift cylinder 18 via a chain anchor bolt. The end is connected to a chain anchor bracket 22 on the lift bracket 12 side via a chain stud.

Therefore, when the free lift cylinder 18 is extended from the state shown in FIG. 2, the lift bracket 12 is independently raised along the inner mast 4 (free lift function), and the lift cylinder 2 is extended as described later. Then, the lift bracket 12 is also moved up integrally with the movement of the middle mast 3 and the inner mast 4. In FIG. 2, reference numeral 23 denotes a tilt bracket, and 24 denotes a mast support bracket.

A pair of left and right chain wheel brackets 25 are fixed to the upper beam 9 connecting the left and right middle masts 3 and 3 to each other. A chain wheel 26 and a wheel 27 for a hydraulic hose are individually arranged side by side on these chain wheel brackets 25. A lift chain 28 for an inner mast is mounted on each chain wheel 26, and a hydraulic chain 27 is mounted on a wheel 27 for each hydraulic hose. Hose 29 is wound around each. These chain wheels 26 and wheels 27 for hydraulic hoses are
Together with the chain wheel bracket 25, it is arranged so as to be within the height difference a between the middle mast 3 and the inner mast 4, and at the same time, as is clear from FIGS. The left and right masts including the inner mast 4 are dimensionally overlapped in both the front-rear direction and the vehicle width direction.

The lift chain 2 for the inner mast
One end of 8 is connected to the upper beam 5 on the outer mast 1 side via a chain anchor bolt 30,
The other end of the inner mast lift chain 28 is a space 3 formed between the middle mast 3 and the inner mast 4.
1 (see FIG. 1) and is also connected to the lower end of the inner mast 4 via a chain anchor bolt 32. Similarly, one end of the hydraulic hose 29 is connected to the upper end of the lift cylinder 2 via a nipple 33 and communicates with the internal space of the cylinder 2.
The other end of 9 passes through a space 31 formed between the middle mast 3 and the inner mast 4 and is connected to the lower end of the inner mast 4 like the other end of the lift chain 28 for the inner mast.

More specifically, as shown in FIGS. 5 and 6 in addition to FIG. 2, a chain anchor bracket 34 is fixedly welded to the lower end of the inner mast 4, and the chain anchor bracket 34 is attached to the lift chain 2 for the inner mast.
8 is the chain anchor bolt 3 on the inner mast 4 side.
5 and a nut 36. An oil hole 37 is formed in the chain anchor bracket 34, and an end on the inner mast 4 side of the hydraulic hose 29 connected to the lift cylinder 2 is provided above the oil hole 37 via a nipple 38. On the other hand, an end of a hydraulic hose 39 for supplying hydraulic pressure to the free lift cylinder 18 is connected to a lower end of the oil hole 37 via a nipple 40.

With the above structure, a portion from the chain wheel 26 to the chain anchor bracket 34 of the inner mast lift chain 28 and the hydraulic hose 29 is not substantially exposed to the outside by passing through the space 31. The lift cylinder 2 and the free lift cylinder 18 are always connected in series via the hydraulic hose 29, the oil hole 37, and the hydraulic hose 39, as shown in FIG.

Therefore, according to the present embodiment, when hydraulic pressure is supplied to the lift cylinder 2 through the control valve 41, the hydraulic oil in the lift cylinder 2 flows into the free lift cylinder 18 and firstly the free lift cylinder As a basic function of the full free mast, the lift bracket 12 moves up independently until the lift bracket 12 reaches the upper end of the inner mast 4.
When the lift bracket 12 reaches the upper end of the inner mast 4, that is, when the free lift cylinder 18 is in the maximum extension state, the lift cylinder 2 starts to extend only from this point in time, and the inner mast 4 is moved with the rising operation of the middle mast 3. Is the chain wheel 26 and the lift chain 28 for the inner mast together with the lift bracket 12.
Suspended through. That is, the inner mast 4 moves up at a speed and a stroke twice as fast as the middle mast 4 in accordance with the rising operation of the middle mast 3.

As described above, of the inner mast lift chain 28 and the hydraulic hose 29, the portion from the chain wheel 26 to the chain anchor bracket 34 is the space 3 between the middle mast 3 and the inner mast 4.
Since it is housed and hidden in 1, the rear sides of the left and right masts are neat and the view is improved clearly, and at the same time, that part does not hinder the view of the operator, The synergistic effect with the reduction of the width dimension of each of the left and right masts can realize a wide field of view of the operator.

FIG. 8 is a view showing a second embodiment of the present invention. As apparent from comparison with FIG. 1, the chain wheel 19 for the lift chain 20 and the chain wheels 26 and The wheels 27 for the hydraulic hoses 29 are each tilted by a predetermined angle. In this embodiment, the same effect as in the first embodiment can be obtained.

FIG. 9 is a view showing a third embodiment of the present invention. A lift cylinder 52 (which is not particularly limited to a ram cylinder or a piston cylinder) having a structure separate from the outer mast 51 is shown. Is arranged on the rear side of the outer mast 51. In this case, the lift chain 2 for the inner mast wound around the chain wheel 26 is used.
8, the portion from the chain wheel 26 to the connection between the inner mast lift chain 28 and the inner mast 4 is housed in the space 31 between the middle mast 3 and the inner mast 4.

In the present embodiment, the portion from the chain wheel 26 to the chain anchor bracket 34 (see FIGS. 5 and 6) of the inner mast lift chain 28 is hidden in the space 31 between the middle mast 3 and the inner mast 4. The inner mast lift chain 28
As far as possible, the rear side of the left and right masts are neat, and at the same time, that part does not hinder the operator's view, and the operator has a wide field of view due to the synergistic effect with the reduction of the width dimensions of the left and right masts Can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention, and is an explanatory plan view of a main part of FIG. 2;

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

FIG. 3 is a view in the direction of arrow A in FIG. 2;

FIG. 4 is a view in the direction of arrow B in FIG. 2;

FIG. 5 is an enlarged view of a portion C in FIG. 2;

FIG. 6 is a further enlarged explanatory view of FIG. 5;

FIG. 7 is a schematic explanatory view of a hydraulic system in the mast device of FIG. 2;

FIG. 8 is an explanatory plan view of a main part showing a second embodiment of the present invention.

FIG. 9 is an explanatory plan view of a main part showing a third embodiment of the present invention.

FIG. 10 is an explanatory plan view showing an example of a conventional mast device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Outer mast 2 ... Lift cylinder 3 ... Middle mast 4 ... Inner mast 15 ... Cylinder tube 16 ... Liner 17 ... Liner 18 ... Free lift cylinder 26 ... Chain wheel 27 ... Hydraulic hose wheel 28 ... Inner mast lift chain 29 ... Hydraulic hose 31 ... space 34 ... chain anchor bracket 37 ... oil hole 39 ... hydraulic hose 51 ... outer mast 52 ... lift cylinder

Claims (5)

[Claims] A lift mast and a free lift cylinder are formed as a full-mast and slide mast, and each of a lift cylinder and a free lift cylinder is a three-stage mast that is independent on the left and right, and is formed between an inner mast and a middle mast. A mast device for a forklift truck, wherein a chain for driving an inner mast is arranged in a space portion. 2. The forklift according to claim 1, wherein a hydraulic hose connected to a free lift cylinder is arranged together with the chain for driving the inner mast in a space formed between the inner mast and the middle mast. Truck mast equipment. 3. A mast device for a forklift truck according to claim 1, wherein a pair of left and right free lift cylinders are arranged behind the corresponding left and right masts. 4. The forklift according to claim 2, wherein the left and right outer masts and the corresponding cylinder tubes of the lift cylinder are formed in advance as one piece, and the lift cylinder is a ram-type cylinder. Truck mast equipment. 5. The forklift truck mast device according to claim 4, wherein the other end of the hydraulic hose connected to the free lift cylinder is connected to the upper end of the lift cylinder.