JPH07187594A - Hydraulic piping structure of free lift height forklift - Google Patents

Abstract

PURPOSE:To increase flexibility of the tension adjusting range of a hose, to make parts common to different lifts, and to improve the forward field of view. CONSTITUTION:Right and left hose guides 7, 8 formed in such a manner as to have a substantially groove-like section for storing a hose 10 disposed like a U-shape are arranged between right and left masts in such a manner that the grooves are opposite to each other. One hose guide 7 is fixed to the outer mast side, and the other hose guide 8 is fixed to the inner mast side. An inner pipe 11 for connecting the hose 10 stored in the inner mast side hose guide 8 to a hose 17 wrapped round a hose pulley 16 which is connected to a hydraulic actuator of the lift bracket side and installed on a free lift cylinder 4 is fixed to a middle tie beam 2b of the inner mast through a clamp 13 in such a manner as to be adjusted vertically in position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic piping structure for a free lift type forklift, and more specifically, a hydraulic pressure for connecting an oil control valve on the vehicle body side and a hydraulic actuator for attachment mounted on a lift bracket. Related to piping structure.

[0002]

2. Description of the Related Art Conventionally, as a hydraulic piping structure of a free lift type forklift of a type in which the inner mast is vertically moved without using a lift chain, a U-shaped bend is formed between the left and right masts with respect to the vertical movement of the inner mast. There is known a hydraulic piping structure of a mast piping system in which flexible hoses arranged in a corresponding manner are used. FIG. 5 schematically shows a main part of a hydraulic piping structure of a free lift type forklift using the conventional U-shaped hose described above. The hydraulic piping structure will be briefly described below. In the figure, two sets of hydraulic pipes are shown, and a pair of left and right hose guides 31 and 32 made of channel members are vertically arranged, one set each on the right side and the left side between the left and right masts. The hose guides 31 arranged on the outer side of each set are fixed to the outer mast (not shown), and the hose guides 32 arranged on the inner side are fixed to the rear surface of the tie beam 33 of the inner mast (not shown). In addition, each group of hose guides 31,
The grooves 32 are arranged such that their grooves face each other, and a flexible hose 34 is bent and housed between the grooves so as to follow the vertical movement of the inner mast.

However, one end of the hose 34 is fixed to the pipe 35 fixed along the hose guide 31 on the outer mast side.
The pipe 35 is connected to an oil control valve on the vehicle body side via a hose (not shown). The other end of the hose 34 is connected to a pipe 36 fixed along the hose guide 32 on the inner mast side, and this pipe 36 is hooked on a hose pulley 38 mounted on a piston rod 37a of a free lift cylinder 37. It is connected to the hose 39, and this hose 39 for hanging the pulley
Is connected to a hydraulic actuator for attachment mounted on a lift bracket (not shown).

Thus, the oil control valve and the hydraulic actuator are connected, and the U-shaped hose 34 housed between the hose guides 31 and 32 changes its bent portion along the groove when the inner mast is moved up and down. However, when the lift bracket is moved up and down, the pulley-hose hose 39 orbits along the hose pulley 38 to follow it. As such a hydraulic piping structure, for example, Japanese Utility Model Publication 4-1199 can be cited.

[0005]

However, in the above-described conventional hydraulic piping structure of a free lift type forklift, since the hose guide 32 and the pipe 36 on the inner mast side are an integral structure by welding, the following problems are encountered. was there. That is, the hose 39 mounted on the hose pulley 38 requires tension adjustment during the piping work, and the hose 3 is accompanied by this tension adjustment.
The position of the pipe 36 connected to 9 is adjusted in the vertical direction in accordance with the hose length, but in that case, not only the pipe position is restricted, but also the hose guide position is restricted. However, there is a problem that the flexibility of the adjustment range is lacking.

Further, in the case of forklifts of the same model, for example, if there are 10 types of specifications with different lifts,
When the hose guide 32 and the pipe 36 are integrally structured,
Since the setting conditions such as the dimensions due to the lift heights interfere with each other, it is difficult to make them common to different lift heights. Furthermore, in addition to the fact that the pipe 36 is welded to the hose guide 32, in addition to requiring a considerable length for welding,
The tie beam 33 for fixing the hose guide 32 needs to have a length that can extend under the tie beam 33 and extend to the front side. As a result, the hose guide 32 hangs down to a position below the tie beam 33 by a considerable length, thereby obstructing the front view. There was a problem of doing.

In view of the above-mentioned problems, the present invention provides a free lift type forklift truck which is more flexible in the range of adjusting the tension of the hose, allows common parts, and is effective in improving the forward field of view. Providing a hydraulic piping structure is a technical problem to be solved.

[0008]

In order to solve the above problems, the present invention is configured as follows. That is, the left and right outer masts that are erected on the machine stand, the left and right inner masts that are vertically movable on the outer masts, the lift brackets that are vertically movable on the inner masts, and the outer masts at the rear of the left and right masts. A hydraulic piping structure of a free-lift forklift including left and right lift cylinders fixed to and vertically moving the inner mast, and a free lift cylinder fixed to the inner mast and vertically moving the lift bracket between the left and right masts. Therefore, the left and right hose guides formed in a substantially groove-shaped cross section to accommodate the U-shaped hydraulic hoses between the left and right masts are arranged vertically so that the grooves face each other, and one hose guide Fixed to the outer mast side, and the other hose guide to the inner mast. A pipe for connecting the hose that is fixed to the inner mast side and passes through the groove of the hose guide on the inner mast side with the hose connected to the hydraulic actuator on the lift bracket side and hung on the hose pulley mounted on the free lift cylinder. Is fixed to the tie beam of the inner mast so as to be adjustable in vertical position.

[0009]

In the hydraulic piping structure of the free lift type forklift according to the present invention constructed as described above, the tension adjustment of the hose mounted on the hose pulley can be handled by adjusting the position of the pipe alone. Further, in setting the dimensions and the like of the hose guide and the pipe, it is possible to set the dimensions and the like under each of those conditions without being interfered with each other in setting the conditions. This increases the degree of freedom in setting. For example, one type of hose guide or pipe can be used for a certain range of lift, and common parts can be used for different lifts. Can be realized. Furthermore, the pipe is non-welded, thus eliminating the need for extra length for welding.
Therefore, it is possible to connect the hoses to each other above the tie beam because the hose can be connected to each other with the minimum required length of the pipe, which is an essential minimum length of the pipe.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a front view showing a mast device and a hydraulic piping structure of a free lift type forklift, and a pair of left and right outer masts 1 erected on a machine base of the forklift.
The left and right inner masts 2 are vertically movably attached to the inside of, and a lift bracket (not shown) is vertically movably attached to the inside of the inner mast 2.

Left and right lift cylinders 3 are erected on the lower cross beams 1a of the outer mast 1 on the rear surfaces of the left and right masts, and their piston rods 3a are connected to the upper tie beams 2a of the inner mast 2. A free lift cylinder 4 is erected on the lower tie beam 2c of the inner mast 2 between the left and right masts, and the middle abdomen is supported by the middle tie beam 2b via a bracket (not shown). The chain wheel 5 is attached to the upper end of the piston rod 4a of the free lift cylinder 4 via the chain wheel bracket 18.
Is provided, and the lift bracket is moved up and down via a lift chain 6 mounted on the chain wheel 5.

Next, in the free lift type forklift configured as described above, a hydraulic piping structure for connecting the oil control valve on the vehicle body side and the hydraulic actuator for attachment mounted on the lift bracket side is shown in FIG. And it demonstrates based on FIG. The present embodiment shows the piping when the lift bracket is equipped with two hydraulic actuators for attachment. However, two pipes, one for oil supply and one for return oil, make up one set, and in the following description, one set for pipe means two.

On the right side and the left side between the masts, a pair of left and right hose guides 7 and 8 each having a groove shape in cross section and formed in an elongated shape are arranged. The hose guides 7 and 8 are arranged so that their grooves face each other, and the right and left hose guides 7 arranged on the mast side are arranged.
The upper and lower parts of the hose guide 8 are fixed to the cross beam of the outer mast 1 through the bracket 7a, the inner right and left hose guides 8 are arranged on the rear surface of the free lift cylinder 4, and the upper and lower parts thereof are the tie beam of the inner mast 2. Is fixed to the bracket via a bracket 8a.

Hereinafter, in this embodiment, the hose guide 7 fixed to the outer mast 1 is referred to as an outer hose guide, and the hose guide 8 fixed to the inner mast 2 is referred to as an inner hose guide. The two sets of inner-side hose guides 8 face each other at a constant interval in a back-to-back state. Further, each outer side hose guide 7 is provided with a pair of outer pipes 9 along the rear surface side thereof, and appropriate portions of the outer pipes 9 are welded to the outer side hose guide 7. The lower end of the outer pipe 9 is connected to an oil control valve (not shown) on the vehicle body side through a hose.

Between the sets of hose guides 7 and 8 arranged as described above, a flexible hose 10 is housed and arranged so as to form a U-shape on the front side. In this U-shaped hose 10, the outer side hose guide side end is connected to the upper end of the outer pipe 9 and the inner side hose guide side end is connected to the inner pipe 11, so that the hose guide 7,
It is supported in a bent state between the grooves of 8 in a hanging state.

The inner pipe 11 is, as shown in FIGS. 3 and 4, the middle tie beam 2b of the inner mast 2.
Is attached to the front surface side of a bracket 12 made of a vertically long plate standing upright in a substantially vertical shape via a clamp 13.
The vertical mounting position is adjustable. That is, the inner pipe 11 is fixed to the inner mast 2 side while being separated from the inner hose guide 8. Specifically, the inner pipe 11 is pressed and fixed by fastening the bolts 14 to the bracket 12 with the clamp 13 formed of a plate having arcuate recesses on the left and right sides covered with the inner pipe 11.
Therefore, the fixed position of the inner pipe 11 with respect to the bracket 12 can be freely adjusted.

The inner pipes 11 are connected to each other by a tie plate 15 in each set to be integrated with each other to facilitate the handling. Further, in this embodiment, among the brackets 12 for the inner pipe, the bracket 12 for the right side is arranged between both the hose guides 8 on the inner side, and the bracket 12 for the left side is arranged on both the outer side and the inner side on the left side. It is arranged between the hose guides 7 and 8.

Then, as described above, the inner mast 2
At the other end of the two left and right inner pipes 11 fixed to the side, a piston rod 4a of the free lift cylinder 4 is provided.
A flexible hose 17 mounted on two pairs of hose pulleys 16 provided on a chain wheel bracket 18 at the upper end of the is connected. Note that one of the two sets of hose pulleys 16 is arranged on the left side coaxially with the chain wheel 5, and the other one is arranged at the center upper part. The hose 17 hung on the hose pulleys 16 is The front end thereof is connected to the hydraulic actuator of the lift bracket via a connector pipe (not shown).

The hydraulic piping structure according to this embodiment is constructed as described above. Therefore, when the free lift cylinder 4 operates for free lift, the hose 17 mounted on the hose pulley 16 attached to the piston rod 4a moves circularly to follow the lifting operation of the lift bracket. On the other hand, when the lift cylinder 3 operates to lift, the inner mast 2 and the free lift cylinder 4 move up and down as a unit, so the inner hose guide 8
Also goes up and down together. At this time, the hose 10 between the left and right hose guides 7 and 8 follows the hose guides 7 and 8 while changing the bent portion.

In the hydraulic piping structure according to the present embodiment, the U-shaped hose 10 housed in the grooves of the hose guides 7 and 8 for protection and the hose 17 fitted with a pulley.
Since the inner pipe 11 for connecting to and from the inner hose guide 8 is separated from the inner hose guide 8 and fixed to the inner mast 2 by pressing with the clamp 13, the tension of the hose 17 hung on the hose pulley 16 is fixed. When the adjustment is performed, it is possible to deal with the adjustment of the position of the inner pipe 11 without receiving the interference of the hose guide 8 on the inner side, so that flexibility in the tension adjustment range can be obtained.

Further, since the inner hose guide 8 and the inner pipe 11 are separate parts, when setting the dimensions and the like, there is no interference of mutual condition setting, and the individual conditions are met. You can set the size and so on. This means that the degree of freedom at the time of setting is increased, and for example, when there are 10 types of lifts for the same type of forklift, one type of hose guide 8 is used for a certain range of lifts. Alternatively, the inner pipe 11 can be used so that the parts can be shared for different lifts. That is, it is possible to expand the range of common use for lift.

Furthermore, by separating the inner pipe 11 from the hose guide 8, an extra length for welding, which is indispensable in the conventional welded integrated structure, is unnecessary. Therefore, since the hose 10, 17 can be connected to each other by the minimum necessary length originally required for the pipe, the hose 10, 1 is provided above the middle tie beam 2b.
7 can be connected to each other, the sagging to the lower side of the middle tie beam 2b can be avoided, and the front view of the lower area of the middle tie beam 2b between the left and right masts can be improved. In particular, in the present embodiment, the inner pipe 11 on one side is arranged on the rear surface of the free lift cylinder 4, which is the range of the original blind spot, so that the presence thereof does not hinder the forward visual field.

In the illustrated embodiment, two sets of hydraulic pipes are provided so as to correspond to the two hydraulic actuators mounted on the lift bracket, but the number of pipes corresponds to the number of hydraulic actuators. Yes, the number is not necessarily limited to two.

[0024]

As described in detail above, according to the present invention,
In a hydraulic piping structure of a free lift type forklift, a hose guide for accommodating and protecting a U-shaped hose,
By configuring the pipe used to connect the hoses to each other as separate parts, flexibility in the tension adjustment range of the hoses to be hooked on the pulley is obtained, and parts are shared for different lifting heights. This has the effect of improving the forward visibility.

[Brief description of drawings]

FIG. 1 is a front view showing a mast device and a hydraulic piping structure of a free-lift type forklift according to an embodiment of the present invention.

FIG. 2 is likewise an exploded perspective view of the hydraulic piping structure.

FIG. 3 is a side view showing an inner pipe mounting structure.

FIG. 4 is a view on arrow A in FIG.

FIG. 5 is an exploded explanatory view showing an outline of a conventional hydraulic piping structure.

[Explanation of symbols]

 1 ... Outer mast 2 ... Inner mast 3 ... Lift cylinder 4 ... Free lift cylinder 6 ... Lift chain 7,8 ... Hose guide 9 ... Outer pipe 10 ... Hose 11 ... Inner pipe 12 ... Bracket 13 ... Clamp

Claims (1)

[Claims] 1. Right and left outer masts erected on a machine stand, left and right inner masts vertically attached to the outer masts, lift brackets vertically movable to the inner masts, and rear left and right masts. In the hydraulic pressure of a free-lift forklift equipped with left and right lift cylinders fixed to the outer mast to move the inner mast up and down, and a free lift cylinder fixed to the inner mast between the left and right masts to move the lift bracket up and down. In the piping structure, the left and right hose guides formed in a substantially groove-shaped cross section to accommodate the U-shaped hose arranged between the left and right masts are arranged vertically so that the grooves face each other. Fix the hose guide to the outer mast side and attach the other hose guide to the inner mast. Pipe for connecting the hose that is fixed to the inner mast side and passes through the groove of the hose guide on the inner mast side with the hose connected to the hydraulic actuator on the lift bracket side and mounted on the hose pulley mounted on the free lift cylinder. A hydraulic piping structure for a free lift type forklift in which the above is fixed to the tie beam of the inner mast so that the position thereof can be adjusted in the vertical direction.