JPS636154Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a mast roller adjustment and replacement mechanism in a forklift truck. When lowering the inner mast with the lift cylinder removed and pulling its lower end downward from the lower end of the outer mast,
The purpose is to improve workability by automatically eliminating interference of a lift cylinder with a chain wheel bracket mounting bracket provided on the inner mast side.

In general, the mast mechanism of a forklift truck consists of an outer mast and an inner mast, and the inner mast is provided so as to be movable up and down relative to the outer mast, which is connected to the aircraft body via a mast roller interposed between the two masts.

However, the mast roller interposed between the two masts may fail, wear out, or be damaged due to the repeated raising and lowering of the inner mast, and must be adjusted and replaced. Since the inner mast is interposed between the inner mast and the outer mast, it is impossible to adjust or replace the inner mast in a normal state, that is, in a state where the inner mast is engaged with the outer mast so as to be able to move up and down. Therefore, in order to adjust and replace the mast roller, it is necessary to expose it from between the two masts.

However, the mast rollers interposed between the two masts are such that the mast rollers interposed near the upper end are axially mounted on the outer mast side, and the mast rollers interposed near the lower end are axially mounted on the inner mast side. Remove the mast roller from between the two masts by disconnecting the mast from the tip of the piston rod that makes up the lift cylinder, and then pulling out the lower end of the inner mast below the lower end of the outer mast. This method has been commonly used in the past.

Specifically, as shown in FIGS. 9 to 13, a chain wheel bracket 10 is attached to the inner mast 2 side.
is integrally provided, and the chain wheel bracket 1
The piston rod 3b of the lift cylinder 3 is directly connected to the piston rod 3, and the inner mast 2 is engaged with the outer mast 1 at the lower end or any intermediate position (Fig. 10). The inner mast 2 is pushed up to the highest position via a (Fig. 11) On the other hand, while the inner mast 2 is suspended via a hoist-type crane or the like 17, the connection between the inner mast 2 and the tip of the piston rod 3b of the lift cylinder 3 is removed, and the lift cylinder 3 is By lowering the inner mast 2 using a hoist crane 17 while tilting it inward (Fig. 12), its lower end is pulled out lower than the lower end of the outer mast 1, and the lift roller 4 and 5 from between the two masts 1 and 2 (Fig. 13), or as shown in Figs. While detachably connecting the
A mounting bracket 14 for the chain wheel bracket 10 is integrally provided on the inner mast 2 side, and the chain wheel bracket 10 is detachably connected to the mounting bracket 14. With the chain wheel bracket 10 removed,
A method is used in which the inner mast 2 is lowered and its lower end is pulled out lower than the lower end of the outer mast 1 (for example, as disclosed in Japanese Utility Model Application No. 116397/1983).

However, in the case of the former method shown in Figures 9 to 13, it is extremely difficult for a single person to work on it, requiring mechanical equipment such as a hoist type crane, and the work is time-consuming. There are problems such as danger.

In the latter method shown in FIGS. 14 to 16, the cylinder rod 3 is
The tip of b must be stepped, and as a fixing means, a screw hole must be opened radially from the peripheral wall, and a specially shaped bolt must be screwed into the screw hole. In addition to the hassle of machining and assembly, the piston rod 3
Since the chain wheel bracket 10 connected to the upper end of the piston rod 3b is located on the center line of the piston rod 3b, the chain wheel bracket 10 interposed between the inner mast 2 and the piston rod 3b is removed. When lowering the mast 2, it is necessary to prevent the guide cover 3' of the cylinder tube 3a on the lift cylinder 3 side from interfering with the mounting bracket 14 on the inner mast 2 side. 3 needs to be provided so as to be shifted inward or rearward with respect to the inner mast 2. However, if the lift cylinder 3 is provided so as to be shifted inward from the inner mast 2, the forward visibility will be narrowed and this will hinder driving. In order to widen the front visibility, which is narrowed by the lift cylinder 3, the chain wheel 12
The chain wheel 12 is provided as close as possible to the lift cylinder 3, but when the chain wheel 12 is provided as close as possible to the lift cylinder 3, the chain 13 hits the lift cylinder 3 and damages the lift cylinder 3, resulting in problems such as oil leakage.

Furthermore, if the lift cylinder 3 is provided shifted to the rear of the inner mast 2, the lost load center will increase, resulting in problems such as a decrease in the allowable load capacity of the fork and an increase in the turning angle of the aircraft. becomes. In addition, in order to solve the above-mentioned problems, the piston rod 3b can be mounted at a biased position relative to the chain wheel bracket 10. In other words, the lift cylinder 3 can be mounted on the chain as shown in FIGS. 17 and 18 and 19 and 20. Although this problem can be solved by connecting the lift cylinder 3 to the outside of the wheel bracket 10, it is not possible to install the lift cylinder 3 so that it is offset to the outside of the chain wheel bracket 10. This results in new problems as described below.

That is, as described above, connecting the lift cylinder 3 to the outside of the chain wheel bracket 10 means that the lift cylinder 3 is vertically opposed to the mounting bracket 14 that is fixed to the inner mast 2 side. However, when the lift cylinder 3 and the mounting bracket 14 are installed vertically opposite each other in this way, when adjusting and replacing/installing/removing the mast roller, the chain wheel bracket 10
When lowering the inner mast 2 with the inner mast 2 removed, the guide cover 3' of the cylinder tube 3a of the lift cylinder 3 will interfere with the mounting bracket 14, as shown in FIGS. This creates the trouble of having to manually tilt the lift cylinder 3 backward. To avoid such trouble, that is, the interference of the guide cover 3' with the mounting bracket 14, it is necessary to reduce the height of the mounting bracket 14 and the thickness width of the front and rear legs of the mounting bracket 14, as shown in FIGS. 17 and 18. However, by reducing the height and the thickness of the legs of the mounting bracket, the distance between the bolts 15 can be narrowed, resulting in sufficient strength. This results in the secondary problem of not being able to do the job properly.

The present invention is an attempt to improve the conventional situation in view of the above-mentioned actual situation.The piston rod of the lift cylinder is biased to the outside of the chain wheel bracket, and the piston rod of the lift cylinder is connected to the chain wheel bracket. This is a mast roller adjustment and replacement mechanism in which a lift cylinder and a lift cylinder are provided vertically relative to each other, and when lowering the inner mast with the chain wheel bracket removed when adjusting and replacing the mast roller. In this method, the lift cylinder can be automatically tilted backwards by raising the piston rod, that is, the interference of the lift cylinder with the mounting bracket can be avoided, and the inner mast can be smoothly pulled out from the lower end of the outer mast. It is characterized by the fact that it is possible to do this.

That is, the gist of the present invention is that a chain wheel bracket is detachably connected to the tip of a piston rod constituting a lift cylinder, and the chain wheel bracket is provided so as to be offset toward the inside of the aircraft body with respect to the center line of the lift cylinder. On the other hand, on the inner mast side, a mounting bracket for the chain wheel bracket is provided vertically corresponding to the lift cylinder.The mounting bracket is formed into an inverted L-shape with a horizontal part and a vertical part. The corner portion formed by the vertical portion is provided with an inclined surface that extends from the vertical portion toward the horizontal portion.

Specific embodiments of the present invention will be described below with reference to the drawings shown in FIGS. 1 to 6.

FIG. 1 is an enlarged perspective view of a part of the mast mechanism, in which reference numeral 1 indicates an outer mast, 2 indicates an inner mast, and 3 indicates a lift cylinder. Although the outer mast 1 is not shown, a pair of outer masts are provided on the left and right opposite each other, and the upper ends of both outer masts are connected by an upper cross beam 1a, and the lower ends are connected by a lower cross beam. connected by 1b. Although the inner mast 2 is also omitted from the drawing, a pair of inner masts are provided on the left and right opposite each other, and the upper ends of the inner masts are connected by an upper tie beam 2a, and the lower ends are connected by a lower tie beam. They are connected by a beam (not shown).
And between both masts 1 and 2 there is a mast roller 4,
5 is interposed, and the inner mast 2 is provided to be movable up and down with respect to the outer mast 1 via a lift cylinder 3. More specifically, on the outer mast 1 side, a mast roller 4 is freely rotatably mounted on the shaft at its upper end, and on the inner mast 2 side, a mast roller 5 is located at its lower end and freely rotatably mounted on the shaft. It will be hung. The lift cylinder 3 consists of a cylinder tube 3a and a piston rod 3b, and the bottom side of the cylinder tube 3a is swingably supported on a lower cross beam 1b on the outer mast 1 side. On the other hand, the head side thereof is fixed to a chain anchor plate 6 extending in an arc shape from the outer mast 1 toward the rear so as to surround the lift cylinder 3. More specifically, a cylinder hook 7 is fixedly fixed downward to the chain anchor plate 6, and a bracket 8 extends from the cylinder tube 3a side to the cylinder hook 7.
are removably fixed through screwing with bolts 9.

A chain wheel bracket 10 is detachably connected to the tip of the piston rod 3b. The chain wheel bracket 10 is composed of a base 10a and a rising portion 10b, and the rising portion 10b is located at a position closer to one side of the base 10a, more specifically, from a connecting hole opening in the center of the base 10a. They are provided so as to stand together in a more vertical direction. The same chain wheel bracket 10 is attached to the base 10.
Bolt 1 into the connecting hole opening in the center of
The chain wheel bracket 10 is removably connected to the piston rod 3b by inserting the bolt 11 and threading the threaded portion of the bolt 11 onto the upper end of the piston rod 3b. It is provided so as to be located inward from the screwing position of the bolt 11. A chain wheel 12 is rotatably mounted on the rising portion 10b, and a chain 13 is mounted on the wheel 12.
is hung. One end of the chain 13 is connected to the chain anchor plate 6, and the other end of the chain 13 is connected to a lift bracket (not shown).

On the other hand, on the inner mast 2 side, a mounting bracket 14 (hereinafter referred to as "mounting bracket 14") for the chain wheel bracket 10 is provided extending downward from the upper tie beam 2a. The mounting bracket 14 is located on the back surface of the inner mast 2 so as to be able to come into contact with the outer surface of the rising portion 10b. In other words, the mounting bracket 14 and the lift cylinder 3 are provided vertically opposite each other. The mounting bracket 14 has a horizontal part 14a extending in the front-rear direction at its upper end and a vertical part 14b extending in the up-down direction at its front end.
formed into a letter shape. At the corner formed on the rear side by the horizontal portion 14a and the vertical portion 14b, there is an inclined surface 14c at an appropriate angle so as to project from the vertical portion 14b toward the horizontal portion 14a.
is formed. And the same mounting bracket 14
The upright portion 10b of the chain wheel bracket 10 is detachably connected to the chain wheel bracket 10 via mounting bolts 15.

Next, its effect will be explained.

3 to 8 are drawings showing the work process for adjusting, replacing and attaching and detaching the mast rollers 4 and 5, and FIG. 3 shows the state in which lifting work is possible, that is, the outer mast 1 is The inner mast 2 is shown engaged at its lowest position. As shown in FIG. 3, when the inner mast 2 is engaged with the outer mast 1 at its lowest position, the inner mast 2 is lifted up via the lift cylinder 3. In this lifted-up state, the support rod 16 is supported between the lower end of the inner mast 3 and the ground surface, as shown in FIG. With the support rod 16 supported on the lower end of the inner mast 3 in this manner, the bolt 9 is loosened to release the bracket 8 from the lift hook 7, and the chain wheel bracket connecting the piston rod 3b and the mounting bracket 14 is removed. 10 is removed. To remove it, remove the bolt 11 connecting the piston rod 3b and the base 10a, and then lower the piston rod 3b and remove the mounting bracket 14 and chain wheel bracket 10.
This can be obtained by removing the bolts 15 connecting the rising portions 10b of. With the chain wheel bracket 10 removed in this manner, the piston rod 3b is pushed upward. The piston rod 3b pushed upward hits the mounting bracket 14, but the mounting bracket 1
4 is provided with an inclined surface 14c, so that the tip of the piston rod 3b that hits the mounting bracket 14 is provided with an inclined surface 14c as shown in FIG.
The effect of sliding along c is obtained. The tip of the piston rod 3b that has slid along the inclined surface 14c in this manner is engaged with the horizontal portion 14a;
By sliding along the inclined surface 14c, an effect of tilting the entire lift cylinder 3 toward the rear can be obtained. With the tip of the piston rod 3b engaged with the horizontal portion 14a of the mounting bracket 14 in this manner, the inner mast 2 is no longer supported by the support rod 16 by pushing the piston rod 3b upward. Can be pushed upwards (7th
figure). Then, the support rod 16 is removed with the inner mast 2 being pushed upward from the position where it is supported by the support rod 16. With the support rod 16 removed, the piston rod 3b is pushed back downward. The effect of lowering the inner mast 2 is obtained by pushing back the piston rod 3b downward. That is, as shown in FIG.
The inner mast 2 can be lowered without the guide cover 3' of the cylinder tube 3a interfering with the cylinder tube 4. In other words, the mast roller 5 that is pivoted on the lower end of the inner mast 2 can be taken out below the lower end of the outer mast 1, and the mast roller 4 that is pivoted on the upper end of the outer mast 1 can be taken out from the inner mast. It can be taken out from the upper end of 2.

The present invention is constructed as described above.
As mentioned above, the piston rod of the lift cylinder is provided vertically corresponding to the mounting bracket of the chain wheel bracket, and the mounting bracket is provided with an inclined surface corresponding to the tip of the piston rod, and the inner mast is supported by a rod. in the process of raising the piston rod to engage the horizontal part of the mounting bracket with the chain wheel bracket removed, raising the tip of the piston rod along the inclined surface;
By making it possible to tilt the lift cylinder backward by raising the piston rod, the guide cover of the lift cylinder does not interfere with the mounting bracket during the process of lowering the inner mast, allowing the inner mast to be moved backwards. It was now possible to pull it out below the lower end of the mast. In other words, the work of lowering the inner mast, adjusting the mast roller, and replacing and removing it can be done easily by a single worker without requiring dangerous work, and without requiring mechanical equipment such as a hoist type crane. We have now been able to improve the workability and safety of the process.

By providing an inclined surface on the mounting bracket and sliding the tip of the piston rod along the inclined surface, the lift cylinder can be automatically tilted backwards.
The lift cylinder can be installed on the outside of the fuselage, that is, behind the inner mast, and can be installed as close to the inner mast as possible.As a result, the conventional structure described above can be We were able to resolve all the problems.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view of a mast mechanism portion equipped with a mast roller adjustment and replacement mechanism according to the present invention, Fig. 2 is a sectional view of the main part, and Figs. 3 to 8 show its operating state. 9 is a perspective view of the appearance of the mast mechanism section showing a conventional structure, FIGS. 10 to 13 are schematic explanatory drawings showing the same operating state, and FIG. 14 is a perspective view of the mast mechanism section also showing the conventional structure. External perspective view, Figures 15 and 16
The figure is a cross-sectional view, and Figures 17 to 20 are drawings showing the adjustment mechanism proposed in the process leading to the present invention. Figures 17 and 19 are perspective views of the mast mechanism, and Figures 18 and 20 are The figure is a sectional view thereof. 1...Outer mast, 1a...Upper cross beam, 1b...Lower cross beam, 2...
Inner mast, 2a... hot tie beam,
3... Lift cylinder, 3a... Cylinder tube, 3b... Piston rod, 3'... Guide cover, 4, 5... Mast roller, 6... Chain anchor plate, 7... Cylinder hook, 8... Bracket, 9...Bolt, 10...
Chain wheel bracket, 10a... Base, 1
0b...Rise part, 11...Bolt, 12...Chain wheel, 13...Chain, 14...Mounting bracket, 14a...Horizontal part, 14b...Vertical part, 14c...Slope, 15...Mounting Bolts, 16...support rods, 17...hoist type cranes, etc.

Claims (1)

[Scope of utility model registration request] A mounting bracket formed into an inverted L shape with a horizontal portion and a vertical portion is provided on the inner mast side, and a chain wheel bracket is removably attached to the mounting bracket, and a piston rod that constitutes a lift cylinder is attached to the chain wheel bracket. A mechanism for adjusting and replacing a mast roller in a forklift truck, in which a chain wheel bracket is connected to the tip of the piston rod in a direction inward of the aircraft body with respect to the centerline of the lift cylinder. The mounting bracket is provided vertically in correspondence with the lift cylinder, and the corner formed by the horizontal and vertical parts of the mounting bracket is provided with a mounting bracket extending from the vertical part toward the horizontal part. A mechanism for adjusting and replacing a mast roller in a forklift truck which is provided with an inclined surface that extends toward the direction of the vehicle.