JP2005067861A - Lift cylinder mounting structure of forklift - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lift cylinder mounting structure of a forklift capable of stopping the extraction and rotation of a lift cylinder from and relative to a mast without increasing production cost resulting from the number of parts and lowering assembly performance/maintainability resulting from troublesome operation. <P>SOLUTION: This forklift is formed such that a mounting boss installed at the bottom part of the lift cylinder is fitted into a mounting hole formed in the lower stay of the mast to mount the lift cylinder at the specified position of the mast. A part of a stopper plate formed of a flat plate is fitted into a recessed groove formed in the outer part of the lift cylinder to fixedly mount the stopper plate on the mast. Thus, the lift cylinder is fixed to the mast so as not to be extracted nor rotated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

    The present invention relates to a lift cylinder mounting structure for a forklift, and more particularly, to a lift cylinder retaining and turning prevention with respect to a mast.

    As shown in FIG. 7, a general forklift (forklift truck) A is equipped with a work machine C in front of a vehicle body (vehicle body) B, and this work machine C operates a lift cylinder (mast lift cylinder) R. Based on the above, the fork F is moved up and down along the mast M erected vertically.

  The lift cylinder R extends in the vertical direction along the mast M, and the upper end of the cylinder rod (not shown) is attached to the inner mast (not shown) of the mast M. As shown in FIG. 8, the lower end of the cylinder tube Rt in the lift cylinder R is fitted with a mounting boss Rb formed at the bottom of the cylinder tube Rt in a mounting hole Lh formed in the lower stay L of the mast M (specifically, outer mast). Is installed by.

  Here, in the lift cylinder mounting structure as described above, the mounting boss Rb of the lift cylinder R is moved to the lower stay L due to the influence of the gravitational acceleration caused by the lifting and lowering of the fork F during the cargo handling operation and the large impact during the traveling. The attachment of the lift cylinder R to the mast M sometimes broke down.

  In order to solve the above-described disadvantages, a forklift having a lift cylinder retaining structure is provided (see, for example, Patent Document 1).

  That is, in the conventional lift cylinder retaining structure, as shown in FIG. 9, after fitting the mounting boss Rb of the lift cylinder R into the mounting hole Lh of the lower stay L, the washer as a stopper is attached to the bottom of the mounting boss Rb. By fastening W with a bolt S, the upward movement of the lift cylinder R with respect to the mast M is restricted, thereby preventing the mounting boss Rb from coming out of the mounting hole Lh.

  On the other hand, since the lift cylinder R is a hydraulic actuator, the lift cylinder R rotates due to a “rampage” when hydraulic fluid is supplied at a high pressure, so that it is impossible for the joint J (see FIG. 9) connecting the lift cylinder R and the hydraulic hose. Inconveniences such as excessive force and inadvertent twisting of the hydraulic hose.

Therefore, in order to eliminate the above inconvenience, as shown in FIG. 9, a pin hole Rp is formed in the bottom of the lift cylinder R, and a pin P planted in the lower stay L is fitted to lift the mast M. A rotation stop structure for restricting the rotation of the cylinder R is provided in combination with the lift cylinder retaining structure described above.
JP 2000-344492 A

    By the way, in the above-described conventional configuration, the lift cylinder retaining structure is composed of a bolt S, a washer W, and the like, and the lift cylinder rotation retaining structure is composed of a combination of a pin P and a pin hole Rp. Therefore, in order to prevent the lift cylinder R from being pulled out and stopped with respect to the mast M, a large number of components are required, resulting in an increase in manufacturing cost.

  Further, in the above-described conventional configuration, the lift cylinder retaining structure and the lift cylinder rotating structure are separate and independent structures. In order to perform the above, there is an inconvenience that an extremely troublesome work is required and the assembly maintainability is lowered.

  The object of the present invention is to prevent the lift cylinder from being pulled out and stopped against the mast without causing an increase in manufacturing cost due to the number of parts and a decrease in assembly maintainability due to complicated work. An object of the present invention is to provide a lift cylinder mounting structure for a forklift that can be performed.

    In order to achieve the above object, a lift cylinder mounting structure for a forklift according to claim 1 is configured such that a mounting boss provided at the bottom of the lift cylinder is fitted into a mounting hole provided in a lower stay of the mast, and the lift cylinder is In a lift cylinder mounting structure for a forklift that is mounted at a predetermined position of the mast, a stopper plate formed from a flat plate is fitted into a recessed groove formed outside the lift cylinder, and the stopper plate is fixedly installed on the mast. By doing so, the lift cylinder is prevented from being pulled out and turned against the mast.

    According to the lift cylinder mounting structure for a forklift according to the present invention, the lift cylinder is prevented from being pulled out and stopped against the mast by the stopper plate fixedly installed on the mast. Stopping will be achieved.

  Further, according to the lift cylinder mounting structure of the forklift according to the present invention, the lift cylinder is prevented from being pulled out and turned against the mast by fixing the stopper plate to the mast. Therefore, it is possible to achieve the retaining and turning prevention.

  Therefore, according to the lift cylinder mounting structure of a forklift according to the present invention, the lift cylinder can be prevented from being removed from the mast without causing an increase in manufacturing cost due to the number of parts and a decrease in assembly maintainability due to complicated work. In addition, it is possible to stop the rotation.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments.
In addition, in the configuration of the forklift to which the present invention is applied, there is basically no difference from the conventional forklift described with reference to FIG.

    1, 2 and 3 show a first embodiment of a lift cylinder mounting structure according to the present invention.

  As shown in FIGS. 1 to 3, the lift cylinder 10 constituting the forklift working machine (see FIG. 7) has a cylindrical mounting boss 11 </ b> B protruding from the bottom thereof, specifically, the lower end of the cylinder tube 11. Has been.

  On the other hand, the mast 20 constituting the forklift working machine (see FIG. 7) has a lower portion, specifically, a lower stay 21 constituting an outer mast (not shown), corresponding to the mounting boss 11B of the lift cylinder 10. A mounting hole 21H having a round hole shape is formed through.

  The lift cylinder 10 is fitted with the mounting boss 11B of the lift cylinder 10 into the mounting hole 21H of the lower stay 21, and the upper or middle portion of the cylinder tube 11 is supported by a clamping means (not shown), so that the lift cylinder 10 has the mast 20 It is attached at a predetermined position.

  As shown in FIGS. 1 to 3, a stopper plate 30, which will be described later, is provided at the bottom of the cylinder tube 11 in the lift cylinder 10, specifically, in the vicinity of the portion where the hydraulic port 11 o is provided on the outer peripheral surface of the cylinder tube 11. A recessed groove 12 to be inserted is formed, and the recessed groove 12 is engraved along a plane perpendicular to the axis of the lift cylinder 10.

  Incidentally, the concave groove 12 of the lift cylinder 10 is machined together with the mounting boss 11B, the hydraulic port 11o and the like when the cylinder tube 11T is manufactured.

  On the other hand, on the upper surface of the lower stay 21, a mount 21M having a predetermined height is formed in the vicinity of the mounting hole 21H described above, and a stopper plate 30 is fixedly installed on the top of the mount 21M.

  The stopper plate 30 is a member formed from a single flat plate having a thickness of about 6 mm, and has a substantially L-shaped planar shape including a base portion 30A and a stopper portion 30B.

  The stopper plate 30 is fixedly installed on the mount 21M of the lower stay 21 by screwing the fastening bolts 40, 40 inserted through the bolt holes 30o, 30o of the base portion 30A into the screw holes 21s, 21s of the mount 21M. In this state, the stopper portion 30 </ b> B of the stopper plate 30 is fitted in the concave groove 12 of the lift cylinder 10.

  In this way, a part of the stopper plate 30 fixedly installed on the lower stay 21 is inserted into the concave groove 12 in the lift cylinder 10, so that the upward movement of the lift cylinder 10 with respect to the mast 20 is restricted. It is possible to prevent the mounting boss 11B from jumping out of the mounting hole 21H and dropping off.

  Here, when the stopper portion 30B of the stopper plate 30 fixedly installed on the lower stay 21 is fitted in the concave groove 12 of the lift cylinder 10, as shown in FIG. Between the concave grooves 12, gaps g and g of 3 to 5 mm are provided.

  Thereby, the impact force that the lift cylinder 10 tries to move up and down with respect to the mast 20 is alleviated by the gap g provided between the stopper portion 30 </ b> B and the concave groove 12.

  Further, in a state where the stopper portion 30B of the stopper plate 30 fixedly installed on the lower stay 21 is fitted in the concave groove 12 of the lift cylinder 10, as shown in FIGS. 2 and 3, the linear edge portion of the stopper portion 30B. 30e is in a state of being in close contact with the linear bottom portion 12a in the concave groove 12.

  In this way, a part of the stopper plate 30 fixedly installed on the lower stay 21 is fitted into the concave groove 12 in the lift cylinder 10, so that inadvertent rotation of the lift cylinder 10 relative to the mast 20 is restricted. A situation in which an excessive force is applied to the joint J (see FIG. 2) is prevented in advance.

  Here, the bolt hole 30o of the stopper plate 30 has a large tolerance (gap) with the inserted fastening bolt 40, and the position of the stopper plate 30 is adjusted when the stopper plate 30 is fixedly installed on the lower stay 21. By doing so, the edge portion 30e of the stopper portion 30B and the bottom portion 12a of the groove 12 can be brought into close contact with each other.

  According to the lift cylinder mounting structure having the above-described structure, the lift cylinder 10 is prevented from being pulled out and stopped with respect to the mast 20 by the stopper plate 30 fixedly installed on the mast 20, so that there are very few components, in other words, parts. The lift cylinder 10 can be prevented from being pulled out and stopped without causing an increase in manufacturing cost due to the number of points.

  Further, according to the lift cylinder mounting structure having the above-described structure, the lift cylinder 10 is prevented from being pulled out and stopped with respect to the mast 20 by fixing the stopper plate 30 to the mast 20. In other words, the lifting and stopping of the lift cylinder 10 can be achieved without degrading the assembly and maintenance performance due to complicated work.

  Furthermore, according to the lift cylinder mounting structure having the above-described configuration, in a forklift in which a pair of lift cylinders 10 are arranged on the left and right sides of the mast 20, the stopper plates 30 are used to prevent and rotate each lift cylinder 10. As described above, since the stopper plate 30 is a member formed from a single flat plate, the stopper plates 30 can be shared.

  That is, when the stopper plate 30 related to one lift cylinder 10 is turned upside down, the stopper plate 30 has the same shape as the stopper plate 30 related to the other lift cylinder 10, so that one stopper plate 30 can be used for both the left and right lift cylinders 10. Since the stopper plate 30 is compatible in this way, the number of types of components does not increase easily, and the management of the components becomes easy. Will be improved.

4, 5 and 6 show a second embodiment of the lift cylinder mounting structure according to the present invention.
As shown in FIGS. 4 to 6, a concave groove 12 ′ into which the stopper plate 30 ′ is fitted is formed on the outer peripheral surface of the cylinder tube 11 ′ in the lift cylinder 10 ′ on the side of the hydraulic port 11 o ′. The concave groove 12 'is engraved along a plane perpendicular to the axis of the lift cylinder 10'.

  On the other hand, on the upper surface of the lower stay 21 ', a mount 21M' having a predetermined height is formed in the vicinity of the mounting hole 21H ', and a stopper plate 30' is fixedly installed on the top of the mount 21M '. .

  The stopper plate 30 'is a member formed from a single flat plate having a thickness of about 6 mm, and has a substantially L-shaped planar shape including a base portion 30A' and a stopper portion 30B '.

  In addition, the stopper plate 30 'is configured such that fastening bolts 40' and 40 'inserted into the bolt holes 30o' and 30o 'of the base portion 30A' are screwed into the screw holes 21s' and 21s' of the mount 21M '. In this state, the stopper portion 30B ′ of the stopper plate 30 ′ is fitted in the concave groove 12 ′ of the lift cylinder 10 ′.

  The lift cylinder mounting structure described above is the lift of the first embodiment shown in FIGS. 1 to 3 except for the planar shape of the concave groove 12 ′ in the lift cylinder 10 ′, the mount 21M ′ in the lower stay 21 ′, and the stopper plate 30 ′. Since it is basically the same as the cylinder mounting structure, components having the same functions as those of the first embodiment are denoted by the same reference numerals as in FIGS. Thus, a detailed description is omitted.

  In the lift cylinder mounting structure of the second embodiment described above, as in the lift cylinder mounting structure of the first embodiment, the manufacturing cost increases due to the number of parts and the assembly maintainability decreases due to complicated work. Therefore, the lift cylinder 10 'can be prevented from being pulled out and stopped.

  Further, in the lift cylinder mounting structure of the second embodiment described above, in the case of a forklift in which a pair of lift cylinders 10 'are arranged on the left and right of the mast 20', one stopper plate 30 'is placed on either the left or right lift. Since it can also be used for the cylinder 10 ', workability related to the manufacture and maintenance of the forklift is remarkably improved.

  By the way, in the first embodiment described above, the concave groove of the lift cylinder constituting the mounting structure is formed on the front surface of the outer peripheral surface of the cylinder tube provided with the hydraulic port, and in the second embodiment described above. Has a concave groove formed on the side surface of the outer peripheral surface of the cylinder tube with respect to the hydraulic port, the formation position of the concave groove constituting the mounting structure with respect to the lift cylinder, and further the planar shape of the stopper plate fitted into the concave groove, It goes without saying that the mount layout and the like in the lower stay can be appropriately set based on various conditions such as the specifications of the forklift.

  In the first embodiment and the second embodiment described above, the stopper plate fixedly installed on the mast lower stay is fitted into the concave groove formed in the bottom of the lift cylinder, so that the lift cylinder can be prevented from being removed and rotated. Although the stopper plate is fixedly installed on the mast through the clamp means member that supports the upper part and middle part of the cylinder tube to the mast, a concave groove is formed on the upper part and middle part of the cylinder tube. By forming and inserting a part of the stopper plate into the concave groove, it is possible to prevent the lift cylinder from being pulled out and stopped against the mast.

1 is an exploded perspective view showing a first embodiment of a lift cylinder mounting structure according to the present invention. The principal part top view which shows 1st Example of the lift cylinder attachment structure which concerns on this invention. The principal part side view seen from the arrow X direction in FIG. 3 which shows 1st Example of the lift cylinder attachment structure which concerns on this invention. The disassembled perspective view which shows 2nd Example of the lift cylinder attachment structure which concerns on this invention. The principal part top view which shows 2nd Example of the lift cylinder attachment structure which concerns on this invention. The principal part side view seen from the arrow Y direction in FIG. 5 which shows 2nd Example of the lift cylinder attachment structure which concerns on this invention. The whole side view which shows notionally the structure of a forklift. The principal part disassembled perspective view which shows the conventional lift cylinder mounting structure. Sectional drawing which shows the principal part which shows the conventional lift cylinder mounting structure.

Explanation of symbols

10, 10 '... lift cylinder,
11B, 11B '... mounting boss,
12, 12 '... concave groove,
20, 20 '... mast,
21,21 '... Lower stay,
21H, 21H '... mounting holes,
30, 30 '... stopper plate.

Claims (1)

A lift cylinder mounting structure for a forklift, in which a mounting boss provided at the bottom of the lift cylinder is fitted into a mounting hole provided in a mast lower stay, and the lift cylinder is mounted at a predetermined position of the mast,
A part of a stopper plate formed from a flat plate is fitted into a concave groove formed outside the lift cylinder, and the stopper plate is fixedly installed on the mast so that the lift cylinder is prevented from being removed from the mast and rotated. Forklift lift cylinder mounting structure characterized by stopping.

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