JP2000203799A - Clamp device of forklift truck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a load from being damaged caused by friction to a gripping surface when unloading work is performed by operating a clamp arm to the opening side in a state where the load is not grounded to the floor surface, in a clamp device of a forklift truck. SOLUTION: Two upper and lower rollers 8 and a belt 9 laid on them and to be rotationally and vertically moved are provided on a gripping surface side of an arm part in a clamp arm 5. The rollers 8 and the belt 9 are movable in a direction perpendicular to the gripping surface. In gripping of a cargo W, the belt 9 is pressed and retracted by the cargo W and regulated in the rotation by a rotation regulating plate 15. In releasing or gripping, the belt is pushed out in the gripping direction by compression coil springs 13 and rotated in follow up to lowering of the cargo W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp device for a forklift used in a cargo handling operation for transporting a load by grasping the load from a lateral direction.

[0002]

2. Description of the Related Art Generally, a forklift clamping device used for cargo handling of box-shaped luggage is provided with a pair of openable and closable opposing left and right clamp arms having a planar gripping surface, and the gripping surface has a gripping surface. A clamp pad made of rubber or the like and having a high coefficient of friction is adhered for cushioning or preventing the load from slipping during transportation.

[0003]

However, when unloading the luggage after gripping, the position where the luggage should be lowered (hereinafter, referred to as the luggage).
It is ideal to perform an opening operation (gripping release) of the clamp arm after confirming that it has completely landed at the (down position). However, in actual work, it is difficult to confirm whether the luggage has landed properly at the lowered position,
Alternatively, for reasons such as being troublesome, the clamp arm may be slowly opened to unload the luggage while the landing is not properly performed. In this case, there is a possibility that the side surface of the load may be scratched by being rubbed against the clamp pad serving as the gripping surface.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a forklift clamping device which clamps a luggage while the luggage does not land on a floor or the like. It is an object of the present invention to prevent a load from rubbing against a gripping surface and being damaged when an unloading operation is performed by operating an arm to an open side.

[0005]

In order to achieve the above object, a forklift clamping device according to the present invention has a configuration as described in each of the claims. Therefore, according to the first aspect of the present invention, when the opposing clamp arm is operated to the closing side and the rotating member is gripped by the rotating member, the rotating member presses the elastic member by the gripping force at that time and the opposite gripping surface side And the rotation is restricted by the rotation restricting means at the moved position. Thus, the load is grasped by the rotating member. Therefore,
Thereafter, the clamp arm can be lifted to lift and carry the load. When the clamp arm is operated to the open side while the load is not landing on the floor or the like after the transport of the load, the rotating member is pushed to the gripping surface side by the elastic member with the opening operation of the clamp arm, and the rotation is restricted. The rotation restriction by the means is released. For this reason, the rotating member that is in contact with the side of the load rotates as the load lowers. That is, according to the present invention, the rotation of the rotating member follows the downward movement of the luggage, so that the luggage on the gripping surface of the luggage is avoided, and damage due to the abrasion can be prevented.

According to the second aspect of the present invention, when the clamp arm is operated to open to lower the gripped luggage, the belt rotates following the lowering operation of the luggage.
Therefore, the luggage does not rub. Furthermore, according to the third aspect of the present invention, when the clamp arm is operated to open to lower the gripped luggage, the roller group rotates following the lowering operation of the luggage. Therefore, the luggage does not rub. As described above, in any of the second and third aspects of the present invention, it is possible to prevent damage caused by rubbing of the load.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. First, based on FIGS.
An embodiment will be described. FIG. 1 is a perspective view showing a forklift clamping device according to the present embodiment. As shown in the figure, a clamp base 3 of a clamp device is vertically mounted on a front surface of a lift bracket 2 as an elevating member that can move up and down along a mast 1 of a forklift. And two rail holders 4 each having a groove-shaped cross section are horizontally fixed.

A pair of left and right clamp arms 5 are disposed in front of the clamp base 3. The left and right clamp arms 5 are rail portions 5a which are attached to the rail holder 4 via rollers (not shown) so as to be laterally movable.
And an arm portion 5b which is fixed to or integral with the outer end of the rail portion 5a and extends forward, is formed in a substantially L-shaped plane. The two clamp arms 5 are opened and closed by being separated from each other or moved in the approaching direction by two upper and lower hydraulic clamp cylinders 6 operable in the driver's seat of the forklift.

The arm portion 5b of each of the clamp arms 5 is formed in a substantially box shape with the facing surface (gripping surface) side opened, and the rotating member 7 is disposed on the opening side. That is, the gripping surface of the clamp arm 5 extends over substantially the entire area of the rotating member 7.
It is constituted by. Hereinafter, details of the rotating member 7 will be described with reference to FIGS. 2 and 3. As shown in the drawing, a rotating member 7 according to the present embodiment has a pair of upper and lower rotatable guide rollers 8 as a belt guide, and a vertical direction mounted on the upper and lower guide rollers 8 has a rotation direction 1. And a plurality of belts 9. The roller shaft 8a that rotatably supports the guide roller 8 is fitted into a long hole 12 that is provided in the front and rear walls 10 of the arm portion 5b and that is long in the gripping direction (left-right direction) and is supported so as to be able to move laterally. I have.
That is, the guide roller 8 and the belt 9 are provided so as to be able to advance and retreat in a direction orthogonal to the gripping surface.

A compression coil spring 13 as an elastic member for constantly pressing the roller shaft 8a in the gripping direction is provided on the side wall 11 on the back surface side (the side where the belt 9 is stored) of the arm portion 5b. The compression coil spring 13 is supported by a cylindrical spring receiver or a pin-shaped spring receiver (not shown) provided on the side wall 11 and is engaged with the roller shaft 8a.
The roller shaft 8a is pressed via the receiving member 14 having a shape. Thus, the belt 9 mounted on the roller 8 is always held at a position where the belt 9 is moved to the gripping surface side (hereinafter, also referred to as advancing), and free rotation is possible at that position.

Further, the side wall 11 of the arm portion 5b is provided with rotation restricting means for restricting rotation by contacting the belt 9 when the belt 9 is moved to the opposite side of the gripping surface (hereinafter also referred to as retreating). The rotation restricting plate 15 is provided at a position facing at least the roller 8 of the belt 9 or substantially over the entire area. Therefore, in order to enhance the effect of restricting the rotation of the belt 9 by the rotation restricting plate 15, it is advantageous that the frictional resistance at the time of contact is large. For this purpose, for example, the rotation restricting plate 15 itself (both the plate and the belt 9) Good) may be formed of a material of a non-slip material such as rubber, a rubber sheet or the like may be attached to the surface, or if the rotation restricting plate 15 is made of metal, the surface may be formed in a rough state. desirable.

According to the clamping device for a forklift constructed as described above, when the clamp arm 5 is operated to the closing side to grip the load W, each of the (A) in FIGS.
As shown in FIG. 5, the belt 9 abutting on the side surface of the load W is pressed by the load W together with the upper and lower guide rollers 8 and retreats while pressing the compression coil spring 13, and the back surface thereof is pressed against the rotation regulating plate 15. As a result, the belt 9 cannot be rotated. Therefore, thereafter, the clamp device can be lifted together with the lift bracket 2 serving as a lifting member to lift and carry the load W.

On the other hand, when the clamp arm 5 is operated to the open side before transporting the load W on the floor surface or the like in order to unload the load W, each of FIGS. As shown in B), as the gripping force is weakened, the upper and lower guide rollers 8 and the belt 9 are advanced toward the gripping surface by the compression coil spring 13, whereby the contact pressure between the belt back surface and the rotation regulating plate 15 is weakened. Belt 9
Can be rotated. Therefore, baggage W is
And slowly descend while landing. That is, since the load W descends while rotating the belt 9 to follow, the rubbing of the load W on the gripping surface is avoided.

As described above, according to the present embodiment, when unloading the load W, the ordinary unloading operation of landing the load W on the floor or the like and then opening the clamp arm 5 to lower the load is performed. Needless to say, even if the clamp arm 5 is opened before the load W lands, the belt 9 constituting the gripping surface of the clamp arm 5 follows the downward movement of the load W. By turning downward, it is possible to prevent damage caused by the load W rubbing against the gripping surface. Therefore, the operator can quickly perform the unloading work, which contributes to an increase in work efficiency. Further, in the present embodiment, since the belt 9 is employed as the rotating member, the luggage W can be gripped on a wide surface, and the luggage W can be gripped in a stable state regardless of the luggage size. It is.

Next, a second embodiment of the present invention will be described with reference to FIGS. In this embodiment, instead of the belt 9, a roller group 16 is employed as a rotating member constituting a gripping surface of the clamp arm 5. That is, a large number of rollers 17 are provided on the gripping surface side of the arm 5b.
Are arranged side by side at predetermined intervals in the vertical direction to form a roller group 16. Each roller 17 can be moved (moved forward and backward) individually with respect to the clamp arm 5 via the elongated hole 12. Assembled. And each roller 17
On the back side of the clamp arm 5,
As in the first embodiment described above, a compression coil spring 13 and a receiving member 14 that constantly bias each roller 17 in the gripping direction are provided, and when each roller 17 retreats,
A rotation regulating plate 15 for regulating the rotation of the roller 17 by contacting the roller 17 is provided.

Therefore, according to the second embodiment configured as described above, when the clamp arm 5 is operated in the closing direction to grip the load W, each roller 17 is retracted and rotated by the gripping force. The rotation is regulated by being pressed against the regulating plate 18. That is, in the gripping state of the load W, the rotation of each roller 17 is restricted, so that the load can be lifted and transported thereafter. Then, when the clamp arm 5 is operated to the open side before the load W arrives on the floor or the like after transportation, the compression coil spring 1 is moved due to the loosening of the gripping force.
3 and the rotation restriction by the rotation restriction plate 15 is released, so that the load W descends while rotating each roller 17 and lands. That is, in the second embodiment, similarly to the case of the above-described first embodiment, it is possible to prevent damage by lowering the load W without rubbing with the gripping surface.

It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present invention. For example, as shown in FIG. 7, for example, as shown in FIG. 7, a guide wheel 8 or a roller shaft 8a serving as the rotating member 7 or a ratchet wheel 18 instead of the roller 17 is used as the rotation restricting means. It is also possible to change to a mechanical lock type in which rotation is restricted by engaging with a concave portion (or a protrusion) of the lock plate 19 provided on the arm portion 5b side. Although not shown, an electromagnetic brake is attached to the rotating member, and a detector such as a limit switch for detecting the forward / backward movement of the rotating member is provided on the arm 5b side. It is also possible to employ a configuration in which the rotation of the rotating member is regulated by operating the electromagnetic brake based on the signal, and the rotation regulation by the electromagnetic brake is released when the vehicle advances. Further, the gripping surface of the clamp arm 5 is constituted by a single belt 9 and a group of rollers 16, which are arranged in the front-rear direction (the longitudinal direction of the arm 5b).
May be divided into a plurality. Although the roller 8 is used as the belt guide, a fixed guide plate having a semicircular curved guide surface may be used instead of the roller 8. Further, as the elastic member for pressing the rotating member in the gripping direction, an elastic rubber may be used instead of the compression coil spring 13.

[0018]

As described in detail above, according to the present invention,
In a forklift clamp device, even if an operation such as releasing the grip to lower the luggage before the luggage lands is performed, the gripping surface is lowered together with the luggage, thereby preventing the luggage of the luggage against the gripping surface. Can be. Therefore, the unloading operation can be performed quickly, and the operation efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a forklift clamping device according to a first embodiment.

FIG. 2 is a perspective view showing a main part of the clamp device according to the first embodiment.

3A and 3B are plan cross-sectional views, wherein FIG. 3A shows a gripping state, and FIG. 3B shows a gripping released state.

FIG. 4 is an explanatory view schematically showing a working mode, and FIG.
Indicates a grip state, and (B) indicates a grip release state.

FIG. 5 is a longitudinal sectional view of a clamp device according to a second embodiment.

FIG. 6 is a sectional view taken along line AA of FIG. 5;

FIG. 7 is an explanatory diagram showing a modification example regarding the rotation restricting means.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Mast 2 ... Lift bracket 5 ... Clamp arm 5b ... Arm part 7 ... Rotating member 8 ... Guide roller 9 ... Belt 12 ... Long hole 13 ... Compression coil spring 14 ... Receiver 15 ... Rotation restriction plate

Claims (3)

[Claims] 1. A clamping device for a forklift having a pair of opposing openable and closable clamp arms, wherein a gripping surface of the clamp arm is rotatable in a vertical direction and movable in a direction perpendicular to the gripping surface. On the other hand, the clamp arm includes an elastic member that constantly presses and rotates the rotating member toward the gripping direction, and restricts rotation of the rotating member when the rotating member moves in the opposite gripping direction. A forklift clamping device, comprising: a rotation restricting means for releasing the restriction when moving in the gripping direction. 2. The forklift clamping device according to claim 1, wherein the rotating member includes at least a pair of upper and lower belt guides and a belt mounted on the belt guides. 3. The forklift clamping device according to claim 1, wherein the rotating member is composed of a number of rollers arranged side by side at appropriate intervals in the vertical direction.