JP4059369B2 - Lift cylinder support device for industrial vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lift cylinder support device for an industrial vehicle such as a forklift.
[0002]
[Prior art]
A lift device in an industrial vehicle such as a forklift is driven up and down by a pair of left and right lift cylinders. As shown in FIG. 10, the pair of lift cylinders 5, 5 are mounted in parallel to the pair of left and right fixed masts 1, 1, and the lower end and the upper part of the support members project from the fixed mast 1. It is supported by. In general, as shown in FIG. 11, the lift cylinder is supported by a hole 6 a formed in the lower stay 6 extending between the lower portions of the left and right fixed masts 1, 1 so as to protrude from the center of the lower end surface of the cylinder 5. The provided convex part 5a is inserted and the movement of the horizontal direction is restrict | limited.
[0003]
FIG. 12 shows a device disclosed in Japanese Patent Laid-Open No. 8-119594 as a support device on the upper side of the lift cylinder. The mounting seat 81 has a concave arc surface substantially the same as the outer diameter of the cylinder tube 5 b of the lift cylinder 5, and is fixed to the upper rear surface of the fixed mast 1. The clamp 82 is a flat plate-like member having a substantially J-shaped cross section having a concave arc surface substantially the same as the outer peripheral diameter of the cylinder tube 5 b of the lift cylinder 5. When the lift cylinder 5 is assembled to the fixed mast 1, the clamp 82 is screwed to the mounting seat 81 in a state where the cylinder tube 5 b is sandwiched between the mounting seat 81 and the clamp 82 via the buffer bodies 83 and 84.
[0004]
FIG. 13 shows another example of the support device on the upper side of the lift cylinder 5. The holder 91 has a stepped through hole having a small diameter at the top and a large diameter at the bottom, the diameter of the top is sufficiently larger than the outside diameter of the piston rod 5c, and the bottom diameter is outside the upper end of the cylinder tube 5b. Slightly larger than the diameter. When the lift cylinder 5 is assembled to the fixed mast 1, the holder 91 is screwed onto a bracket 92 projecting rearward from the upper portion of the fixed mast 1 with the holder 91 placed on the upper end of the cylinder tube 5 b. Set up.
[0005]
[Problems to be solved by the invention]
However, the above prior art has the following problems.
In the method of sandwiching and supporting the cylinder tube 5b from the side surfaces with the two members 81 and 82 as shown in FIG. 11, the cylinder tube 5b can be adjusted to be in close contact with the outer diameter of the cylinder tube 5b. Although it has a restraining force and prevents vibration, a sufficient restraining force cannot be obtained in the vertical direction (axial direction). For this reason, when a large external force in the axial direction is applied to the lift cylinder 5 due to rough road traveling or the like, the lift cylinder 5 may float upward and the convex portion 5a at the lower end of the cylinder may come out of the hole 6a of the lower stay 6. . In order to prevent the lift cylinder 5 from coming off, for example, it is necessary to provide an anti-detachment structure at the lower end of the cylinder, which complicates the assembling work at the lower end of the cylinder and increases costs.
Further, in the method of supporting the upper end portion of the cylinder tube 5b with the stepped annular member 91 as shown in FIG. 12, it is possible to prevent the lift cylinder 5 from falling off while having a restraining force in the axial direction. In consideration of assembly and ease of assembly, a radial gap is provided between the upper end of the cylinder and the inner diameter of the holder 91, so that vibration occurs in the lateral direction.
[0006]
SUMMARY OF THE INVENTION In order to solve the above-described problems, an object of the present invention is to provide a lift cylinder support device for an industrial vehicle that can suppress lateral vibration of the lift cylinder and reliably prevent the cylinder from dropping off. .
[0007]
[Means, actions and effects for solving the problems]
In order to achieve the above object, the present invention provides a lift for an industrial vehicle comprising a pair of support members that sandwich and support the outer surface of a cylinder tube of a lift cylinder installed upright along a mast from a substantially opposing direction. In the cylinder support device, one of the support members includes a semi-cylindrical portion that is substantially D-shaped or substantially J-shaped in plan view and has an inner peripheral surface that is slightly larger than the outer peripheral surface of the cylinder tube, The support member includes a mounting portion on the vehicle body side, an upper leg portion that bends and extends from the upper end of the mounting portion and can contact the upper end surface of the cylinder tube without contacting the piston rod, and the mounting portion A lower leg portion having a distal end having a concave arc surface substantially the same as an outer peripheral surface of the cylinder tube which is bent from the lower end to the same side as the upper leg portion and extends to be in contact with a side surface of the cylinder tube; Board It is characterized in that it.
Further, in the lift cylinder support device for an industrial vehicle provided with a pair of support members that sandwich and support the outer surface of the cylinder tube of the lift cylinder erected along the mast from a substantially opposing direction, one of the support members Includes a semi-cylindrical portion that is substantially D-shaped or substantially J-shaped in plan view and has an inner peripheral surface that is slightly larger than the outer peripheral surface of the cylinder tube, and the cylinder without contacting the piston rod An inwardly projecting abutting portion capable of abutting on an upper end surface of the tube, and the other support member includes a mounting portion on a vehicle body side and a bent portion extending from the upper end of the mounting portion. An upper leg portion having a tip having a concave arcuate surface substantially equivalent to the outer peripheral surface of the cylinder tube capable of abutting on the side surface of the cylinder tube, and bends and extends from the lower end of the mounting portion to the same side as the upper leg portion. Shi A lower leg portion having a tip end having a concave arc surface that is concentric with a tip end of the upper leg portion capable of contacting the side surface of the Linda tube and substantially equal to an outer peripheral surface of the cylinder tube is provided.
[0008]
According to the present invention, since the outer surface of the cylinder tube of the lift cylinder is supported from the opposing direction by the two support members, it has a restraining force in the lateral direction of the lift cylinder and can suppress lateral vibration. Since at least one of the two support members includes a contact portion that can contact the upper end surface of the cylinder tube, a large external force in the axial direction is applied to the lift cylinder due to a rough road traveling of the vehicle. Even if the lift cylinder floats to such an extent that it falls off, the contact portion can hold the upper end surface of the cylinder tube and restrain the upward movement of the lift cylinder, so that the lift cylinder can be reliably prevented from falling off.
Further, the one supporting member is a member having a mounting portion on the vehicle body side, an upper leg portion that can be in contact with the upper end surface of the cylinder tube, and a lower leg portion that can be in contact with the side surface of the cylinder tube. In some cases, the sheet material can be easily manufactured by sheet metal processing. In particular, since the upper leg portion only needs to have a function of contacting the upper end surface of the cylinder tube at the lower surface, the dimensional accuracy of the upper leg portion including the positional relationship with the lower leg portion may be rough, so that the cost can be reduced.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, a lift device in an industrial vehicle such as a forklift includes a pair of left and right fixed masts 1, 1 mounted on the front of the vehicle, and a fixed mast 1 that can be raised and lowered along the fixed masts 1, 1. A pair of left and right movable masts 2 and 2 attached to 1, a fingerboard 3 attached to the movable masts 2 and 2 so as to be movable up and down along the movable masts 2 and 2, and a front part of the fingerboard 3 It has a pair of left and right forks 4 and 4.
A pair of lift cylinders 5, 5 are mounted on the fixed masts 1, 1 behind the fixed masts 1, 1 in parallel with the fixed masts 1, 1, respectively. The lower end portion of the lift cylinder 5 protrudes from the center of the lower end surface of the cylinder tube 5b of the lift cylinder 5 in a hole 6a (see FIG. 11) formed in the lower stay 6 installed between the lower portions of the left and right fixed masts 1 and 1. The raised portion 5a is inserted and supported, and the upper end portion of the cylinder tube 5b of the lift cylinder 5 is supported by a support device 10 described later.
[0010]
The piston rod 5c of the lift cylinder 5 is fixed to a head stay 6 that extends between the upper portions of the left and right movable masts 2,2. A pulley 7 is attached to the upper portion of the movable mast 2, and a chain 8 having one end fixed to the fixed mast 1 and the other end fixed to the fingerboard 3 is wound around the pulley 7.
With the above configuration, the movable mast 2 is driven up and down by driving the lift cylinder 5 to extend and contract, and the fingerboard 3 and the fork 4 are driven up and down via the chain 8.
[0011]
A first embodiment of the support device on the upper side of the lift cylinder 5 will be described in detail with reference to FIGS. 2 and 3.
The support device 10 supports the lift cylinder 5 by sandwiching the cylinder tube 5b between the clamp 11 and the support 12 which are support members and screwing the cylinder tube 5 to the bracket 9 attached to the fixed mast 1.
The clamp 11 is a semi-cylindrical portion having an inner peripheral surface that is slightly larger than the outer peripheral surface of the cylinder tube 5b. 11 a, leg portions 11 b and 11 b extending from the semi-cylindrical portion 11 a, and attachment portions 11 c and 11 c that are bent inward from the tip ends of the leg portions 11 b and 11 b and are opposed to each other at the tip ends. The attachment portion 11c is provided with U-shaped notches 11d and 11d from the tip.
[0012]
The support 12 has a width H slightly narrower than the outer diameter of the cylinder tube 5b, and is formed so as to form a substantially U-shape when a plate member whose width direction is the front-rear direction of the vehicle is viewed from the front-rear direction. There are a mounting portion 12c having two inner and rear nuts 12d and 12d welded to the inner surface, an upper leg portion 12a bent from the upper end of the mounting portion 12c and extending in the horizontal direction, and bent from the lower end of the mounting portion 12c in the horizontal direction. The lower leg portion 12b extends. The tip of the lower leg portion 12b has a concave arc surface substantially equivalent to the outer peripheral surface of the cylinder tube 5b. The tip of the upper leg 12a has a concave arc surface that is concentric with the concave arc surface of the tip of the lower leg portion 12b and has a diameter that is larger than the outer diameter of the piston rod 5c and smaller than the outer diameter of the cylinder tube 5b. Yes.
[0013]
The bracket 9 is a flat plate projecting rearward from the left and right outer surfaces of the fixed mast 1 at a position substantially the same as the upper end of the cylinder tube 5b. Directional long holes 9a and 9a are provided.
As parts used when the support device 10 is mounted, there are bolts 15 and 15, a shock-absorbing bush 17 fixed to the metal plate 16, collars 18 and 18 that manage a tightening margin of the bush 17, and a shim 19.
[0014]
An operation of assembling the lift cylinder 5 to the fixed mast 1 using the support device 10 will be described. First, the convex portion 5 a at the lower end of the lift cylinder 5 is fitted into the hole 6 a of the lower stay 6. Next, with the support 12 in a state where the lower surface of the upper leg portion 12a is in contact with the upper end surface of the cylinder tube 5b and the concave arc surface of the lower leg portion 12b is in contact with the outer periphery of the cylinder tube 5b, the clamp 11 is fixed to the cylinder tube 5b. The clamp 11 is disposed so as to cover the side surface of the upper end portion of the clamp 11 and the support 12 so that the inner surface of the semi-cylindrical portion 11a of the clamp 11 and the concave arc surface of the lower leg portion 12b of the support 12 are in close contact with the outer periphery of the cylinder tube 5b. The shim 19 is pushed in between the mounting portion 11 c and the mounting portion 12 c of the support 12, and the cylinder tube 5 b is sandwiched between the clamp 11 and the support 12. Next, the bolt 15 is screwed into the nut 12d of the support 12 with the bracket 9, the collar 18 and the bush 17 interposed therebetween, whereby the assembly of the lift cylinder 5 to the fixed mast 1 is completed.
If necessary, a shim 19 is inserted between the mounting portion 11c of the clamp 11 and the bracket 9 to adjust the parallelism between the lift cylinder 5 and the fixed mast 1.
[0015]
According to the present embodiment, the upper leg 12a of the support 12 restrains the upper end surface of the cylinder tube 5b even when an axial external force is applied to the lift cylinder 5 due to a rough road traveling of the vehicle. The convex part 5 a at the lower end of the lower stay 6 does not come out of the hole 6 a of the lower stay 6. As a result, the lift cylinder 5 can be prevented from falling off, and the lower end portion of the lift cylinder 5 does not need to be provided with a retaining structure, and only needs to be attached to the upper end portion. The combination of the convex portion 5a and the hole 6a is sufficient. The assembly work is not complicated and the cost can be reduced.
Further, since the support device 10 uses two opposing support surfaces, that is, the inner surface of the semi-cylindrical portion 11a of the clamp 11 and the concave arc surface of the lower leg portion 12b of the support 12, the support device 10 has an outer peripheral surface of the cylinder tube 5b. The shim 19 can be adjusted so that the two support surfaces are in close contact. As a result, the support device 10 also has a restraining force in the lateral direction of the lift cylinder 5, and can suppress vibration in the lateral direction of the lift cylinder 5.
Further, the support 12 having the upper leg portion 12a as a contact portion can be easily manufactured by processing a plate material into a sheet metal. In particular, since the upper leg portion 12a only needs to have a function of contacting the upper end surface of the cylinder tube 5b at the lower surface, the dimensional accuracy of the upper leg portion 12a including the positional relationship with the lower leg portion 12b may be rough, so that the cost is reduced. Can be manufactured low.
[0016]
A second embodiment of the support device 20 on the upper side of the lift cylinder 5 will be described with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. The clamp 21 is a semi-cylindrical portion having an inner peripheral surface that is slightly larger than the outer peripheral surface of the cylinder tube 5b. 21a, leg portions 21b and 21b extending from the semi-cylindrical portion 21a, and attachment portions 21c which are bent inward from the tips of the leg portions 21b and 21b and face the tips. Nuts 21d and 21d are welded to the inner surface of the attachment portion 21c, respectively.
[0017]
The support 22 has a width approximately equal to the outer diameter of the cylinder tube 5b, and is formed so as to form a substantially U-shape when a plate member whose width direction is the front-rear direction of the vehicle is viewed from the front-rear direction. An attachment portion 22c provided with two attachment holes 22d, 22d, an upper leg portion 22a bent from the upper end of the attachment portion 22c and extending in the horizontal direction, and a lower leg bent from the lower end of the attachment portion 22c and extended in the horizontal direction Part 22b. The tip of the lower leg portion 22b has a concave arc surface substantially equivalent to the outer peripheral surface of the cylinder tube 5b. The tip of the upper leg 22a has a concave arc surface that is concentric with the concave arc surface of the tip of the lower leg portion 22b and has a diameter that is larger than the outer diameter of the piston rod 5c and smaller than the outer diameter of the cylinder tube 5b. Yes. Further, the distance between the upper leg portion 22 a and the lower leg portion 22 b is slightly larger than the width of the clamp 21.
[0018]
An operation of assembling the lift cylinder 5 to the fixed mast 1 using the support device 20 will be described. First, the convex portion 5 a at the lower end of the lift cylinder 5 is fitted into the hole 6 a of the lower stay 6. Next, the clamp 21 is disposed so as to cover the side surface of the upper end portion of the cylinder tube 5b, and the support 22 has the lower surface of the upper leg portion 22a at the upper end surface of the cylinder tube 5b and the concave arc surface of the lower leg portion 22b. The bracket 9, the collar 18, and the bush 17 are in contact with the outer periphery of the cylinder tube 5 b (at this time, the attachment portion 22 c of the clamp 21 is located between the upper leg portion 22 a and the lower leg portion 22 b of the support 22). The bolts 15 are temporarily fixed to the nuts 21d of the clamps 21 and the shims 19 are inserted between the mounting portions 22c of the support 22 and the brackets 9 as necessary, so that the lift cylinder 5 and the fixed mast 1 are parallel to each other. Adjust the degree. Next, the temporarily tightened bolt 15 is tightened to complete the assembly of the lift cylinder 5 to the fixed mast 1.
[0019]
According to this embodiment, similarly to the first embodiment, even if an axial external force acts on the lift cylinder 5 due to a rough road traveling of the vehicle, the upper leg portion 22a of the support 22 is the upper end surface of the cylinder tube 5b. Therefore, the convex portion 5 a at the lower end of the lift cylinder 5 does not come out of the hole 6 a of the lower stay 6. As a result, the lift cylinder 5 can be prevented from falling off, and the lower end portion of the lift cylinder 5 does not need to be provided with a retaining structure, and only needs to be attached to the upper end portion. The combination of the convex portion 5a and the hole 6a is sufficient. The assembly work is not complicated and the cost can be reduced.
Further, as the tightening force of the bolt 15 is increased, the clamping force by the two opposing support surfaces of the inner surface of the semi-cylindrical portion 21a of the clamp 21 and the concave arc surface of the lower leg portion 22b of the support 22 can be increased. Thereby, it has sufficient restraining force also in the lateral direction of the lift cylinder 5, can suppress the lateral vibration of the lift cylinder 5, and can also support a certain amount of external force in the axial direction. The load on the upper leg portion 22a of the support 22 can be reduced, and the durability can be improved.
Further, the support 22 having the upper leg portion 22a which is an abutting portion can be easily manufactured by processing a plate material. In particular, since the upper leg portion 22a only needs to have a function of contacting the upper end surface of the cylinder tube 5b at the lower surface, the dimensional accuracy of the upper leg portion 22a including the positional relationship with the lower leg portion 22b may be rough, so that the cost is reduced. Can be manufactured low.
[0020]
In the embodiment described above, the example in which the upper legs 12a and 22a of the supports 12 and 22 are used as members capable of contacting the upper end surface of the cylinder tube 5b has been described. However, as shown in FIG. The one or more claws 31e protruding inward from the upper end of the semi-cylindrical portion 31a of the clamp 31 may be configured to have the function. In this case, a member that can contact the upper end surface of the cylinder tube 5b is not necessary on the support 32 side, and the upper leg portion 32a may have the same shape as the lower leg portion 32b and comes into contact with the outer periphery of the cylinder tube 5b. . Although the claw 31e is illustrated as being formed by bending, it may be formed by other methods such as welding.
Moreover, although the support 12 demonstrated in the example which press-molded the board | plate material and welded the nut 12d, a block shape may be sufficient. For example, the support 42 shown in FIG. 6 replaces the support 32 shown in FIG. 5, and the support 52 shown in FIG. 7 (having a protrusion 52a corresponding to the upper leg 12a) is the support described in FIG. Instead of twelve. Each of the supports 42 and 52 includes two screw holes 42d, 42d, 52d, and 52d.
Moreover, although the shape of the site | part contact | abutted on the outer periphery of the cylinder tube 5b was demonstrated in the example of the circular arc, as shown in FIG. 8, the clamp 61 and the support 62 whose contact surface to the outer periphery of the cylinder tube 5b is flat are shown. It may be used.
Further, as shown in FIG. 9, a clamp 71 having a substantially J-shaped cross section may be used instead of the substantially D-shaped cross section.
[0021]
Furthermore, although the member which can contact | abut to the upper end surface of the cylinder tube 5b was demonstrated in the example provided in any one of a support and a clamp, you may provide in both.
In the description of the embodiment, a member that can contact the upper end surface of the cylinder tube 5b (the upper leg portion 12a of the support 12, the claw 31e of the clamp 31, etc.) is in contact with the upper end surface of the cylinder tube 5b. In the example of assembling the lift cylinder 5, the contactable member and the upper end surface of the cylinder tube 5b are separated from each other by a predetermined distance (so that the convex portion 5a at the lower end of the cylinder does not come out of the hole 6a of the lower stay 6). May be assembled. As a result, the upper end surface of the cylinder tube 5b is not subjected to the repeated load received when suppressing small vibrations generated during normal work or normal travel, and only when the lift cylinder 5 floats to such an extent that it drops off due to rough road travel or the like. Since only the reaction force to be pressed is received, the durability of the member that can come into contact with the upper end surface of the cylinder tube 5b can be improved.
[0022]
As described above, according to the present invention, since the upper end side surface of the cylinder tube is supported with the two support members being in close contact with each other, the lateral vibration of the lift cylinder can be suppressed. Since the member capable of contacting the upper end surface is provided, it is possible to reliably prevent the lift cylinder from dropping even if the lift cylinder floats to such an extent that the lift cylinder falls off due to traveling on a rough road or the like.
[Brief description of the drawings]
FIG. 1 is a side view of a lift device to which the present invention is applied.
FIG. 2 is a partial plan sectional view of the first embodiment of the present invention.
FIG. 3 is an exploded perspective view of the first embodiment of the present invention.
FIG. 4 is an exploded perspective view and a partial plan sectional view of a second embodiment of the present invention.
FIG. 5 is an exploded perspective view and a plan view of another aspect of the embodiment of the present invention.
FIG. 6 is a perspective view of another aspect of the embodiment of the present invention.
FIG. 7 is a perspective view of another aspect of the embodiment of the present invention.
FIG. 8 is an exploded perspective view and a plan view of another aspect of the embodiment of the present invention.
FIG. 9 is a perspective view of another aspect of the embodiment of the present invention.
FIG. 10 is an explanatory diagram of the prior art.
FIG. 11 is an explanatory diagram of a conventional technique.
FIG. 12 is a cross-sectional plan view of a prior art support device.
FIG. 13 is a side view of a prior art support device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Fixed mast, 2 ... Movable mast, 5 ... Lift cylinder, 5b ... Cylinder tube, 5c ... Piston rod, 9 ... Bracket, 10, 20 ... Supporting device, 11, 21, 31, 61, 71 ... Clamp, 11a, 21a, 31a ... semi-cylindrical part, 11c, 21c ... mounting part, 12, 22, 32, 42, 52, 62 ... support, 12a, 22a, 32a, 52a ... upper leg part, 12b, 22b, 32b ... lower leg part, 12c, 22c ... mounting portion, 17 ... bush, 18 ... collar, 19 ... shim, 31e ... claw.

Claims (2)

An industrial vehicle comprising a pair of support members (11, 12) that support by sandwiching and supporting the outer surface of a cylinder tube (5b) of a lift cylinder (5) erected along a mast (1) from a substantially opposite direction. In the lift cylinder support device,
One of the support members (11) includes a semi-cylindrical portion that is substantially D-shaped or substantially J-shaped in plan view and has an inner peripheral surface that is slightly larger than the outer peripheral surface of the cylinder tube (5b),
The other support member (12) includes a mounting portion (12c) on the vehicle body side and a cylinder tube (5b) that is bent from the upper end of the mounting portion (12c) and does not contact the piston rod (5c). ) And an upper leg portion (12a) capable of contacting the upper end surface of the cylinder tube (5b) .The upper leg portion (12a) is bent from the lower end of the mounting portion (12c) to the same side as the upper leg portion (12a). A lift cylinder support for an industrial vehicle, comprising: a lower leg portion (12b) having a tip having a concave arc surface substantially equivalent to an outer peripheral surface of the cylinder tube (5b) capable of contacting the cylinder tube (5b) apparatus. Industrial vehicle provided with a pair of support members (31, 32) that sandwich and support the outer surface of the cylinder tube (5b) of the lift cylinder (5) erected along the mast (1) from a substantially opposing direction. In the lift cylinder support device of
One of the support members (31) is substantially D-shaped or substantially J-shaped in plan view, and includes a semi-cylindrical portion having an inner peripheral surface slightly larger than the outer peripheral surface of the cylinder tube (5b). And an inwardly projecting contact portion (31e) capable of contacting the upper end surface of the cylinder tube (5b) without contacting the piston rod (5c),
The other support member (32) includes a mounting portion on the vehicle body side, and an outer periphery of the cylinder tube (5b) that bends and extends from the upper end of the mounting portion and can contact the side surface of the cylinder tube (5b). An upper leg (32a) having a tip having a concave arcuate surface substantially equivalent to the surface, and bends and extends from the lower end of the mounting portion to the same side as the upper leg (32a) of the cylinder tube (5b). A lower leg portion (32b) having a tip that is concentric with the tip of the upper leg portion (32a) capable of contacting a side surface and has a concave arc surface substantially equivalent to the outer peripheral surface of the cylinder tube (5b). An industrial vehicle lift cylinder support device.

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