JP2005082399A - Side shifting device for forklift - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small side shifting device for a forklift in forward and backward directions with a bending force not applied to a tilt cylinder. <P>SOLUTION: This device comprises a lift bracket 6 elevatable along a mast 4 supported by a vehicle body 1, a fork carriage 7 supported at a top of the lift bracket 6 side-shiftably and tiltably, a fork 8 supported by the fork carriage 7, and a tilt cylinder 18 supported by the bottom of the lift bracket 6 and shrunk toward the bottom of the fork carriage 7. The fork carriage 7 is provided with a receiving member 19 installed opposite to the tilt cylinder 18, and a roller 23 rollable in a side-shift direction of the fork carriage 7 in contact with the receiving member 19 is provided at an end on the receiving member 19 side of the tilt cylinder 18. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a side shift device for a forklift that horizontally moves a fork in a predetermined direction.

  In a forklift in which a fork is tiltably supported by a lift bracket, for example, a reach-type forklift, a technique for supporting a fork on a lift bracket so as to be side-shiftable is described in, for example, Patent Document 1 and Patent Document 2 described later. . In addition, a configuration in which a roller that makes rolling contact with a guide rail provided on a fork carriage (fork mounting frame) is supported on the tip of a piston rod of a tilt cylinder in order to drive the fork is described in Patent Document 3 described later. Yes. Further, as a side shift device for a counterbalance type forklift, a configuration in which a roller to be brought into rolling contact with a fork support portion is supported by a lift bracket is described in Patent Document 4 described later.

JP 11-246197 A JP-A-6-16399 Japanese Utility Model Publication No. 50-153672 Japanese Patent Laid-Open No. 11-209089

  In the reach-type forklift side shift device described in Patent Document 1 above, a tilt bar (between the fork carriage (laterally movable body) supporting the fork and the lift bracket (elevating body) is used to tilt-drive the fork. Since the tilting body is interposed, there are a large number of parts and a problem that the side shift device becomes large in the front-rear direction.

  In the side shift device of the reach type forklift described in the above-mentioned Patent Document 2, since the tilt bar is omitted, the number of parts is small, and the side shift device becomes small in the front-rear direction. However, during side shift, friction is generated between the wear resistant member (sliding strip) fixed to the fork carriage (front part) and the tilt cylinder, and bending force is applied to the tilt cylinder. It is necessary to increase the strength. Further, there is a problem that the wear of the wear-resistant member progresses during use over a long period of time and the tilt angle changes.

  If the tilt drive device for a forklift described in Patent Document 3 is applied when the fork is provided so that it can be side-shifted, the rotational axis of the roller that is in rolling contact with the guide rail provided on the fork carriage is side-mounted. It must be directed in the shift direction. Therefore, friction occurs between the guide rail and the roller during the side shift, and a bending force is applied to the tilt cylinder. Further, there is a problem that the tilt angle changes due to wear of the guide rail and the roller abutting against the guide rail.

  In the side shift device described in Patent Document 4, when the fork carriage (fork support portion) is tilted, the roller supported by the lift bracket is separated from the fork carriage. A side shift device cannot be applied.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a side shift device for a forklift that is small in the front-rear direction and does not apply bending force to the tilt cylinder.

  In order to achieve the above object, a forklift side shift device according to the present invention includes a lift bracket that can be lifted and lowered along a mast supported by a vehicle body, and a side shiftable and tiltable upper portion of the lift bracket. A fork carriage to be supported; a fork supported by the fork carriage; and a tilt cylinder supported by a lower portion of the lift bracket and extending and contracting toward a lower portion of the fork carriage; A receiving member provided opposite to the tilt cylinder, and a roller abutting on the receiving member and capable of rolling in the side shift direction of the fork carriage at the end of the tilt cylinder on the receiving member side; Adopting technical means characterized by that.

  In the present invention, if a barrel roller having a convex curved outer peripheral portion that contacts the receiving member is used as the roller, the friction between the receiving member and the roller can be reduced when the fork carriage is tilt-driven. In addition, a smooth tilt operation can be realized.

  In the present invention, if a rotation preventing means for preventing the roller from rotating about the axis of the tilt cylinder is provided, the roller can reliably hold the state of rolling in the side shift direction of the fork carriage. It is possible to always enjoy the effects of the present invention.

  According to the present invention, since the fork carriage is tilt-driven directly by the tilt cylinder, the tilt bar is unnecessary, and the side shift device can be made smaller in the front-rear direction accordingly. Further, when the fork carriage is side-shifted, the roller that contacts the receiving member rolls, so that the bending force does not act on the tilt cylinder, and wear of the receiving member and the roller is suppressed, so that the tilt angle from the initial state is reduced. Can be used for a long time without change.

  An embodiment of the present invention will be specifically described with reference to the drawings as follows. 1 is a longitudinal side view of a side shift device of a forklift according to one embodiment of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a side view showing an enlarged main portion thereof. FIG. 4 is a side view of the forklift. In the following, the fork side of the vehicle is referred to as the front, and the vehicle width direction is referred to as the left and right.

  As shown in FIG. 4, the forklift according to this embodiment is a reach-type forklift, and left and right reach legs 2 are provided forward from the front portion of the vehicle body 1, and the reach carriage 3 is moved forward and backward in both reach legs 2. Supported as possible. A mast 4 is erected at the front end portion of the reach carriage 3, and a side shift device 5 is supported along the mast 4 so as to be movable up and down.

  As shown in FIGS. 1 and 2, the side shift device 5 includes a lift bracket 6 supported by the mast 4 so as to be movable up and down, and a fork carriage supported by the lift bracket 6 so as to be side-shiftable and tiltable. 7 and left and right forks 8 supported by the fork carriage 7. A shaft 9 is horizontally provided on the upper part of the lift bracket 6 in the left-right direction, and a bracket 10 provided on the upper part of the fork carriage 7 is supported on the shaft 9 so that the fork carriage 7 and the fork 8 are supported. It can be rotated around the shaft 9, that is, can be tilted, and can move horizontally in the axial direction of the shaft 9, that is, can be side-shifted.

  The fork carriage 7 includes a bracket 10, an upper rail 11 fixed to the upper portion of the bracket 10, and a lower rail 13 fixed to the upper rail 11 via a connecting plate 12. The fork 8 includes the fork The fork carriage 7 is fitted into the upper and lower rails 11 and 13 by an upper fixture 15 fixed to the upper rear portion of the vertical portion 14 and a lower fixture 16 fixed to the lower rear portion of the vertical portion 14 respectively. It is supported by. Further, the lift bracket 6 is provided with left and right vertical plate frames 17, and tilt cylinders 18 made of hydraulic cylinders are fixed to the lower portions of the vertical plate frames 17 so as to extend and contract toward the fork carriage 7 slightly downwards forward. Is done.

  As shown in FIGS. 1 and 3, a receiving member 19 is provided on the back surface of the connecting plate 12 of the fork carriage 7 so as to face the tilt cylinder 18. On the tilt cylinder 18 side of the receiving member 19, a receiving surface 20 is formed that is a plane perpendicular to the axial direction of the tilt cylinder 18 in a state where the upper surface of the fork 8 is horizontal (tilt angle is 0 °). The outer peripheral portion of the roller 23 supported by the front end of the piston rod 21 of the tilt cylinder 18 via the bracket 22 is brought into contact with the receiving surface 20. As a result, when the tilt cylinder 18 expands and contracts, the fork carriage 7 is directly tilt driven.

  As shown in FIG. 3, the roller 23 is a barrel-shaped roller whose outer peripheral portion is a convex curved surface. The roller 23 is vertical when viewed from the front and centered on an axis orthogonal to the axial direction of the tilt cylinder 18 when viewed from the side. It is supported by the bracket 22 so as to be able to roll, and rolls in the side shift direction of the fork carriage 7. Using a barrel-shaped roller as in this embodiment is desirable because it can maintain good contact between the receiving surface 20 and the outer peripheral portion of the roller 23 when the fork carriage 7 is tilted. That is, for example, when the tilt cylinder 18 is extended, the crossing angle between the axial direction aa of the tilt cylinder 18 and the receiving surface 20 changes from 90 °, which is an orthogonal state. Tilt is driven upward (tilted up) along the outer peripheral portion of 23. At this time, since the receiving surface 20 moves so as to be orthogonal to the normal line nn of the outer peripheral portion of the roller 23 at the contact point with the roller 23, the contact state between the receiving surface 20 and the outer peripheral portion of the roller 23 is The tilt driving force by the tilt cylinder 18 is appropriately applied to the receiving surface 20. Further, since the occurrence of slip between the roller 23 and the receiving surface 20 is prevented, uneven wear of the roller 23 and the receiving surface 20 due to the slip can be eliminated. Since the contact area is small, friction can be suppressed and a smooth tilt operation can be realized.

  As shown in FIG. 1, the side shift device 5 is provided with an anti-rotation means 24 that prevents the roller 23 from rotating around the axis of the tilt cylinder 18. The rotation preventing means 24 is provided on the vertical plate frame 17 of the lift bracket 6 on the lower surface of the bracket 22 that supports the roller 25 and the guide 25 provided to protrude forward at a position below the tilt cylinder 18. A pin 27 is formed in the guide 25 and inserted into a long hole 26 that is long in the axial direction of the tilt cylinder 18. When the tilt cylinder 18 is expanded and contracted, the long hole 26 is inserted in the state where the pin 27 is inserted into the long hole 26. To move along.

  Note that the side shift operation of the fork carriage 7 is performed by extending and contracting a shift cylinder 28 formed of a hydraulic cylinder mounted between the bracket 10 and the lift bracket 6 of the fork carriage 7 so that the fork carriage 7 is horizontal in the axial direction of the shaft 9. This is done by moving it.

  As described above, the side shift device 5 according to this embodiment eliminates the tilt bar and tilts the fork carriage 7 directly with the tilt cylinder 18, so that the side shift device 5 is small in the front-rear direction. Can be Further, when the fork carriage 7 is side-shifted, the roller 23 in contact with the receiving member 19 rolls in the side-shift direction of the fork carriage 7, so that the bending force does not act on the tilt cylinder 18. In addition, since the wear of the receiving member 19 and the roller 23 is greatly reduced, the durability of the side shift device 5 is enhanced, and it can be used for a long time without changing the tilt angle.

  In this embodiment, the roller 23 made of a barrel-shaped roller is brought into contact with the receiving member 19 having the receiving surface 20, so that the contact state between the roller 23 and the receiving surface 20 is good regardless of the tilt angle. Therefore, the tilt operation of the fork carriage 7 can be performed smoothly.

  Furthermore, in this embodiment, since the rotation preventing means 24 for preventing the roller 23 from rotating around the axis of the tilt cylinder 18 is provided, the roller 23 rotates around the axis of the tilt cylinder 18 and the side. It is possible to reliably prevent the shift operation and the tilt operation from being out of order.

  Although the case where the present invention is applied to the reach type forklift has been described above, the forklift to which the present invention is applied is not limited to the reach type forklift, and may be, for example, a counterbalance type forklift.

It is a side view of the present invention. It is a front view of the present invention. It is a side view of the present invention. It is a side view of a forklift to which the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Car body 4 Mast 6 Lift bracket 7 Fork carriage 8 Fork 18 Tilt cylinder 19 Receiving member 20 Receiving surface 23 Roller 24 Anti-rotation means

Claims (3)

A lift bracket that can be moved up and down along a mast supported by the vehicle body; a fork carriage that is supported in a side-shiftable and tiltable manner at an upper portion of the lift bracket; and a fork supported by the fork carriage; A tilt cylinder supported by the lower part of the lift bracket and extending and contracting toward the lower part of the fork carriage;
Further, the fork carriage includes a receiving member provided to face the tilt cylinder. The end of the tilt cylinder on the receiving member side is in contact with the receiving member so that the fork carriage moves in the side shift direction. A side shift device for a forklift, comprising a roller capable of rolling.   The forklift side shift device according to claim 1, wherein the roller is a barrel-shaped roller whose outer peripheral portion in contact with the receiving member is a convex curved surface.   3. The side shift device for a forklift according to claim 1, further comprising anti-rotation means for preventing the roller from rotating about the axis of the tilt cylinder.

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