JP3132833U - Lift cylinder stroke adjusting device - Google Patents

Abstract

An object of the present invention is to provide a lift cylinder stroke adjustment mechanism that facilitates adjustment work of a shim adjustment mechanism and does not partially apply a large load.
In a lift cylinder of a forklift, a projecting portion 67 having a rod groove 68 formed near a lower end is provided above a piston rod 66 and is disposed through a through hole 72 of a cylinder mounting portion 71. When the left and right cylinder strokes are different, the cylinder mounting portion 71 is raised to a height at which the rod groove is exposed, and the rod groove 68 has a C-shaped notch with the same or slightly larger width as the rod groove 68. The coasting is adjusted by inserting the shim 73 from the side.
[Selection] Figure 2

Description

  The present invention relates to a lift cylinder stroke adjusting device for a forklift, and more particularly to a stroke adjusting device for adjusting the heights of left and right lift cylinders at the stroke ends to coincide with each other.

  Conventionally, in a forklift of a type in which lift cylinders 51 are respectively arranged behind the left and right inner masts 50 as shown in FIG. 8, a cylinder mounting portion in which the upper end of the piston rod 52 of the lift cylinder 51 is protruded rearward of the inner mast 50. 53 is connected by a bolt 54. Further, an inner mast beam 55 that connects the upper ends of the left and right inner masts 50 is provided. In such a forklift, when product dimensional errors and assembly errors overlap, the stroke end height of the lift cylinder 51 may be different on the left and right, and a coasting phenomenon may appear and the inner mast 50 may not operate smoothly. Therefore, coasting adjustment is performed, for example, by connecting a shim 56 between the upper end surface of the piston rod 52 of the lift cylinder 51 on one side and the cylinder mounting portion 53 with a bolt 54. By the way, the presence or absence of the coasting phenomenon must be confirmed by raising the inner mast 50 to the highest level. Therefore, in coasting adjustment with the shim 56 interposed, the inner mast is lowered and the bolt 54 is removed when the stroke end height of the lift cylinder 51 is different between the left and right. Then, the cylinder mounting portion 53 is floated upward with respect to the piston rod 52 to make a gap, and after the shim 56 is interposed in the gap, the bolts 54 are tightened again, and then the inner mast 50 needs to be raised to the highest level for confirmation. It was.

On the other hand, in order to eliminate the work of removing the bolt and facilitate the adjustment work, Patent Document 1 has a structure in which the opening 10a is provided in the cylinder support 10 so that the shim 12 having the notch 12a can be inserted from the side. It is disclosed. As another method, in Patent Document 2, a through hole 2 that penetrates the head of the piston rod 6 of the lift cylinder 15 is formed in the upper connecting member 22 of the mast, and the upper connecting member 22 is formed in the piston rod 29. Accordingly, there is disclosed a structure in which the circumferential groove 3 is engraved with being spaced apart in the vertical direction, and a plurality of snap rings 6 are fitted into the circumferential groove 3 to fix the upper connecting member 22.
JP-A-1-247396 Japanese Utility Model Publication No. 57-81296

By the way, in patent document 1, the disk-shaped shim 12 in which the notch 12a of a dimension a little larger than a bolt diameter was used was used, and it was necessary to control shim separation from the side. For this reason, it is necessary to use the regulating member 11 and the positioning bolt 14, resulting in an increase in the number of parts and an increase in work.
In Patent Document 2, coasting adjustment is performed by adjusting the number of snap rings 6 in the circumferential groove 3 by adjusting the number of upper and lower parts. However, a plurality of snap rings 6 are required, which increases the number of parts and assembly work. Yes. Furthermore, since the upper connecting member 22 is connected to the piston rod 29 by the snap ring 6, a large local load is applied to the snap ring 6, which may cause cracks or chipping.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a lift cylinder stroke adjustment mechanism that facilitates the adjustment work of the shim adjustment mechanism and does not partially apply a large load.

  In order to solve the above problems, the device according to claim 1 is provided with an inner mast that can be raised and lowered with respect to the outer mast, and a lift cylinder for raising and lowering the inner mast. In a forklift mast device connected to a cylinder mounting portion provided in an inner mast, a shim having a protruding portion extending upward and a notch portion having a width smaller than the diameter of the piston rod can be inserted into the piston rod. The cylinder mounting portion is provided with a through-hole through which the protruding portion can pass, the cylinder mounting portion is moved to a position above the rod groove, and the shim is removed from the rod groove. The gist is that the distance between the upper end surface of the piston rod and the cylinder mounting portion can be adjusted by insertion or withdrawal. That.

  According to this, in the coasting adjustment, the cylinder mounting portion may be lifted up above the rod groove and the shim having the notch portion may be inserted from the rod groove, and an increase in work man-hours and the number of parts can be suppressed. Further, the load applied to the cylinder mounting portion can be received by the entire upper surface of the shim and supported together with the piston rod.

  According to a second aspect of the present invention, in the lift cylinder stroke adjusting mechanism according to the first aspect, the upper end of the projecting portion of the piston rod is fixed with a bolt having a diameter larger than the diameter of the through hole. This is the gist.

  According to this, when the cylinder mounting portion is lifted up above the rod groove in coasting adjustment, the cylinder mounting portion does not come off from the protruding portion of the piston rod, and the increase in work man-hours can be reliably suppressed. .

The invention according to claim 3 is the stroke adjusting mechanism of the lift cylinder according to claim 1, wherein a rod groove is formed near the upper end of the protruding portion of the piston rod and a snap ring is fitted. And
According to this, the number of parts can be further reduced.

  According to the present invention, the adjustment operation of the shim adjustment mechanism can be facilitated, and a lift cylinder stroke adjustment mechanism that does not partially apply a large load can be provided.

(First embodiment)
Hereinafter, a first embodiment will be described with reference to FIGS.
The forklift 60 has a mast 62 erected in front of the vehicle body 61. The mast 62 can be moved up and down along the outer mast 63 inside the outer mast 63. It is comprised from the inner mast 64 fitted by. A lift cylinder 65 for raising and lowering the inner mast 64 is provided behind the mast 62 so as to follow the outer mast 63 and the inner mast 64.

  A piston rod 66 that can be expanded and contracted with respect to the main body of the lift cylinder 65 extends upward from the upper end portion of the lift cylinder 65. From the upper end surface 66a of the piston rod 66, as shown in FIG. Also, a substantially cylindrical protrusion 67 having a small diameter and a step is provided so as to extend and contract integrally with the piston rod 66. A step-shaped rod groove 68 in which the diameter of the protruding portion 67 is reduced is provided at a position slightly above the lower end of the protruding portion 67. The thickness of the rod groove 68 (vertical groove width in FIG. 2) is set to be larger than the thickness of a C-type shim 73 described in detail later, and is about 2 to 3 mm. Further, a screw hole is provided at the upper end of the protruding portion 67, and a washer 69 is fixed by a bolt 70.

  The piston rod 66 protrudes from the inner mast 64 toward the rear of the vehicle so as to be fitted to a lower end portion of a cylinder mounting portion 71 provided on the upper portion of the lift cylinder 65. Further, the piston mounting portion 71 protrudes from the cylinder mounting portion 71. A through hole 72 through which the portion 67 can penetrate is provided. The cylinder mounting portion 71 is provided with a cylindrical recess 71 b on the lower surface 71 a, which has a diameter slightly larger than the diameter of the piston rod 66 of the lift cylinder 65. The piston rod 66 and the cylinder mounting portion 71 are in a fitted state, and only a slight gap remains between them, and the piston rod 66 is supported in a substantially contacted state. Moreover, the through-hole 72 which penetrates the protrusion part 67 of the piston rod 66 has a large diameter with respect to the protrusion part 67, and is maintained at a distance that does not come into contact with the through-hole.

  In the first embodiment, the C type shown in FIG. 3 is used for adjusting the distance between the upper end surface 66a of the piston rod 66 and the lower surface 71a of the cylinder mounting portion 71, more specifically, the inner and lower end surfaces 71c, which are cylindrical recesses 71b. A shim 73 is inserted. The C-type shim 73 is a thin disk, and has a hole 73a that is slightly larger than the diameter of the protruding portion 67 of the piston rod 66 at the center. Furthermore, a notch 73b is provided in a part of the circumferential direction. The notch 73b has a narrower width than the diameter of the central hole 73a, that is, the diameter of the protrusion 67 of the piston rod. Further, the width of the notch 73b is formed to be slightly larger than the diameter of the rod groove 68 of the protrusion 67. The C-type shim 73 is set in several types depending on the thicknesses of 0.5 mm, 1 mm, and 2 mm, and is appropriately selected and used.

Next, the procedure for adjusting the cylinder stroke of the lift cylinder 65 at the upper end of the piston rod 66 configured as described above will be described with reference to FIG.
First, at the time of normal mast assembly, the inner mast 64 and the cylinder mounting portion 71 are lowered from the top of the piston rod 66 with the washer 69 and the bolt 70 removed, and the cylinder mounting portion 71 is placed on the upper end of the piston rod 66. That is, the cylindrical recess 71b is fitted and supported. At this time, the C-type shim 73 is not inserted. Next, a washer 69 is fixed to the upper end of the protrusion 67 with a bolt 70.

  After assembling the mast in this manner, the piston rod 66 is extended to the maximum extension state, that is, to the stroke end, and a check is made as to whether a coasting phenomenon occurs. Here, if there is no left / right inclination at the highest position of the inner mast 64, there is no need to adjust the cylinder stroke, and therefore the inner mast 64 is lowered to complete the assembly.

  However, the inner mast 64 may be tilted left and right when the inner mast 64 is in the highest position. Therefore, as shown in FIG. 2, a C-type shim 73 is inserted between the upper end surface 66a of the piston rod 66 and the inner lower end surface 71c of the cylinder mounting portion 71 to adjust the cylinder stroke length. Here, the case where the C-type shim 73 is inserted on the assumption that the stroke end height of the left lift cylinder 65 shown in FIG.

  First, after confirming the presence or absence of the lameness phenomenon in the inner mast 64 in the maximum stretched state, a board or the like (not shown) is placed below the inner mast 64 or below the inner mast beam (not shown). When the inner mast 64 is lowered to the lowest position, the piston rod 66 contracts to the lowest lowered position as shown in FIG. 4, but the inner mast 64 is held by the planks before the lowest lowered position. At this time, the inner mast 64 is positioned such that the lower surface 71 a of the cylinder mounting portion 71 is above the position of the rod groove 68 provided near the lower end of the protruding portion 67 of the piston rod 66.

  Next, with the lower surface 71 a of the cylinder mounting portion 71 held above the rod groove 68, the notch 73 b of the C-type shim 73 shown in FIG. 3 is aligned along the rod groove 68 of the protruding portion 67. Insert from the side. The width of the notch 73b of the C-type shim 73 is set to be approximately the same as or slightly larger than the diameter of the protruding portion 67, and can be easily inserted if the C-type shim 73 is kept in a horizontal state. The inserted C-shaped shim 73 is lowered downward from the height position of the rod groove 68, that is, to the upper end surface 66a of the piston rod 66 in a state where the central hole 73a and the protrusion 67 are concentric. Finally, when the inner mast 64 is slightly raised and floated from the planks, the planks are removed, and the inner mast is lowered to the end, the insertion work of the C-type shim 73 is completed.

  After inserting the C-type shim 73, the inner mast 64 is again extended to the maximum extension state, and the stroke end heights of the left and right lift cylinders 65 are rechecked. If the stroke difference is still large, a plurality of C-type shims 73 may be inserted by repeating the above procedure. If the stroke end height on the side where the C-type shim 73 is inserted becomes too high, the C-type shim 73 can be pulled out from the rod groove 68 in the reverse procedure.

In the first embodiment, the following effects can be obtained.
(1) Since the C-type shim 73 provided with the protrusion 67 on the upper end surface 66a of the piston rod 66 and having the notch 73b is used, the C-type shim 73 can be inserted without removing the bolt 70 in the stroke adjustment operation. Work becomes easy and man-hours can be reduced.
(2) Further, a rod groove 68 is provided in the vicinity of the lower end of the protrusion 67 of the piston rod 66, the width of the notch 73 b of the C-type shim 73 is narrower than the diameter of the protrusion 67, and the diameter of the rod groove 68. Since the widths are almost the same, it is possible to insert from the rod groove 68.

(3) Furthermore, since the rod groove 68 is positioned slightly above the lower end of the protrusion 67, the C-type shim 73 can be lowered to the upper end surface 66a of the piston rod 66 after being inserted from the rod groove 68. Since the width of the notch 73b of the mold shim 73 is narrower than the diameter of the protrusion 67, the C-type shim 73 is stably held without being pulled out sideways. Further, there is no need for a regulating member for preventing the C-type shim 73 from coming out, and the number of parts can be reduced.

(3) Since the washer 69 is fixed to the upper end of the protruding portion 67 with the bolt 70, the cylinder mounting portion 71 is not detached from the protruding portion 67 even when the cylinder mounting portion 71 is lifted in the stroke adjustment operation. Further, it is possible to suppress an increase in the process of fitting the cylinder mounting portion 71 to the protruding portion 67 again.
(4) Since the piston rod 66 supports the cylinder mounting portion 71 via the C-type shim 73, the load applied to the cylinder mounting portion 71, that is, the inner mast 64, can be received by the entire upper surface of the C-type shim 73. It is possible to avoid the occurrence of a place where a partly heavy load is applied.

(5) When the cylinder mounting portion 71 and the piston rod 66 are fitted, the cylindrical recess 71b of the cylinder mounting portion 71 is substantially the same size as the diameter of the piston rod 66. With respect to the load in the direction, it can be supported by the thick piston rod 66 instead of a thin member like the protruding portion 67.
(6) The protrusion 67 of the piston rod 66 is sufficiently high with respect to the through hole 72 of the cylinder mounting portion 71, so that the pull-out that occurs when the inner mast 64 behaves upward is reduced. Can do. Further, even when the cylindrical recess 71b of the cylinder mounting portion 71 is detached from the piston rod 66 by being greatly bounced, the protruding portion 67 serves as a guide, and the fitting position can be maintained.

The present invention is not limited to the configuration of each of the embodiments described above, and various modifications are possible within the scope of the spirit of the present invention, and can be implemented as follows.
In the above embodiment, the washer 69 provided on the upper portion of the projecting portion 67 is fastened by the bolt 70, but a new retaining groove 80 is provided above the projecting portion 67 as shown in FIG. It may be changed to the one to insert. By using the snap ring, the number of parts can be further reduced.

  Further, as shown in FIG. 6, a cylinder mounting portion holding groove 82 may be provided near the center of the protruding portion 67. In this case, considering that the C-type shim 73 is inserted for coasting adjustment, the thickness of the groove 82 having the thickness of the plurality of C-type shims 73 is preferably set. In this configuration, after the assembly similar to that of the first embodiment is performed, the cylinder mounting portion 71 can be held by inserting a single or a plurality of snap rings 81 into the groove 82, so that the traveling road surface It is possible to reliably prevent the cylinder mounting portion 71 from floating with respect to the piston rod 66 or the C-type shim 73 due to the unevenness.

  As shown in FIG. 7, the width of the notch 83a of the C-type shim 83 may not be constant. By setting the width to increase in the outer circumferential direction, the C-type shim 83 can be easily inserted when inserted into the rod groove 68, and the workability is improved.

It is a forklift side view in a 1st embodiment. It is the elements on larger scale near the piston rod upper end part in a 1st embodiment. It is a top view of the C type shim in a 1st embodiment. It is an assembly figure at the time of C type shim insertion in a 1st embodiment. It is the elements on larger scale of the piston rod upper end part in the example of a change. It is the elements on larger scale of the piston rod upper end part in the example of a change. It is a top view of the C-type shim in the example of a change. It is the schematic of the conventional mast.

Explanation of symbols

60 ... Forklift, 61 ... Car body, 62 ... Mast, 63 ... Outer mast, 64 ... Inner mast, 65 ... Lift cylinder, 66 ... Piston rod, 66a ... Upper end surface, 67 ... Projection, 68 ... Rod groove, 69 ... Washer, 70 ... Bolt, 71 ... Cylinder mounting part, 71a ... Lower surface, 71b ... Cylindrical recess, 71c ... Inner and lower end faces, 72 ... Through hole, 73 ... C-type shim, 73a ... Hole, 73b ... Notch, 80 ... Draining groove , 81 ... snap ring, 82 ... groove for retaining, 83 ... C-type shim.

Claims (3)

The inner mast is provided to be movable up and down with respect to the outer mast, and includes a lift cylinder for raising and lowering the inner mast.
In the mast device for forklifts, the upper end portion of the piston rod of the lift cylinder is connected to the cylinder mounting portion provided in the inner mast.
The piston rod has a protrusion extending upward,
A rod groove through which a shim having a notch with a width narrower than the diameter of the protruding portion can be inserted;
The cylinder mounting portion includes a through hole through which the protruding portion can pass,
The cylinder mounting portion is moved to a position above the rod groove, and the shim is inserted or pulled out from the rod groove so that the distance between the upper end surface of the piston rod and the cylinder mounting portion can be adjusted. Stroke adjustment mechanism for lift cylinder.   2. The lift cylinder stroke adjusting mechanism according to claim 1, wherein a washer having a diameter larger than the diameter of the through hole is fixed to the upper end of the protruding portion of the piston rod by a bolt.   2. The lift cylinder stroke adjusting mechanism according to claim 1, wherein a snap groove is fitted into a rod groove for preventing the stopper rod from being formed near an upper end of the protruding portion of the piston rod.

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