JPS6118520B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a roll clamp for a forklift for handling roll-shaped articles (hereinafter simply referred to as rolls) such as newspaper or craft paper.

A roll clamp, which is rotatably mounted in a vertical plane on the lifting device of a forklift, basically consists of two arms: a fixed arm and an opposing clamp arm. In order to conveniently grip rolls placed horizontally, the front length of the clamp arm located above is made longer than the front length of the fixed arm located below. However, if the front lengths of both arms are different, it is often inconvenient when handling rolls placed vertically, so it is possible to change the front lengths of both arms to positions with equal and unequal positions. has been proposed. One known example is one in which the fixed arm is a swing arm, which is rotated on the same axis as the clamp arm. However, in a type in which this single axis is used as the rotation fulcrum of both arms, the single axis is located a certain distance from the rotation center line of the rotating seat, and the clamp arm and swing arm are Since the setting is such that when the two arms change to unequal positions, the midpoint of both arms, that is, the center of the gripped roll, will be located on the center of the rotating seat, so both arms extend the same length. When the rolls are of equal length, the roll center naturally deviates from the rotation center line of the rotary seat. As a result, in the work of vertically gripping the roll with both arms changed to the same length position,
The center of the roll deviates from the center line of rotation of the rotary seat, that is, the center line of the vehicle in the longitudinal direction, resulting in an imbalance of load in the left and right direction.Especially when lifting the roll high for vertical gripping, the roll clamp itself Not only that, but the stability of the forklift will be compromised.

Therefore, a two-shaft type roll clamp has been proposed in order to solve the problems seen in the single-shaft type roll clamp as described above. In this method, the support shaft of the swing arm is provided at a position away from the rotation center line of the rotating seat, and the support shaft of the clamp arm is provided at approximately the midpoint of the swing arm near the rotation center line of the rotating seat.
Then, the length of the swing arm from the spindle, which is the rotation fulcrum of the clamp arm, to the tip of the swing arm is set equal to the length to the tip of the clamp arm, and both arms can be selectively rotated around their own spindles. It is designed so that it can be rotated. Therefore, according to a two-axis type roll clamp, vertical gripping that changes both arms to an equal length state requires that the roll center, which is the midpoint of both arms, be brought close to the rotation center line of the rotating seat. As a result, there is almost no load imbalance in the left-right direction, and stable transportation is possible. However, in vertical gripping, in order to position the roll center close to the rotation center line of the rotating seat, when both arms extend at unequal lengths due to horizontal sliding, the midpoint must be on the rotation center line of the rotating seat. In other words, the radius of the horizontally gripped roll must be smaller than the vertical distance from the center of rotation of the rotary seat to the tip of the swing arm.

In other words, with a biaxial type roll clamp, it is possible to stably shift to vertical placement only when the center of the horizontally gripped roll is deviated toward the swing arm, and the handling range in a stable state is limited. is limited to rolls with a radius smaller than the vertical distance. If you are dealing with a roll with a larger radius, that is, a roll with a larger diameter where the center of the roll deviates upwards than the center of rotation of the rotating seat, when both arms are changed to the same length state, The center of the roll is further separated from the center of rotation of the rotary seat, and the unbalanced load in the left and right direction during vertical gripping is large, and stability is significantly impaired. As a result, the biaxial type roll clamp has the disadvantage that the gripping range is limited to rolls with a smaller diameter compared to the size of the vehicle body, and the range of roll diameters that can be handled is narrow.

The present invention was made for the purpose of eliminating the above-mentioned conventional problems, and when changing the swing arm and clamp arm from a position where they extend at unequal lengths to a position where they extend at equal lengths, the tip of the swing arm For rolls with a small radius relative to the distance from We provide a forklift roll clamp that can reduce the eccentricity of the center of the roll as much as possible, making it possible to handle a wide range of rolls from small diameter rolls to large diameter rolls in a stable state. be.

Hereinafter, illustrated embodiments embodying the present invention will be described in detail. Lift bracket 2 of a lifting device that moves up and down along a mast 1 in a forklift
On the front, there is a rotation support plate 3 in the roll clamp.
is attached via a carrier 4, and a rotary seat 5, which is rotatably attached to the front surface of the rotary support plate 3 in a vertical plane, is rotated by a drive device 6 whose drive source is an oil motor. The center of rotation coincides with the longitudinal centerline of the vehicle.

In front of the rotary seat 5, a pair of arms 7 and 8 that can be selectively opened and closed are installed vertically opposite each other, and the tips of both arms 7 and 8 are opposed to each other so as to grip the surface of the roll W. Pats 9 and 10 having concave arcuate surfaces are rotatably mounted by hinges 11 and 12, respectively. The swing arm 7 disposed on the lower side has its base end above the rotating seat 5 and extends downwardly and forwardly from this point across the center of rotation of the rotating seat 5. The base end of the swing arm 7 is a support shaft 1 with rolls 13 at both ends.
4 so as to be rotatable in the vertical direction, and the roller 13 of this support shaft 14 is supported by a rotary seat 5.
The swing arm 7 is rotatably fitted into a pair of left and right guide rails 15 having a groove-shaped cross section that are attached to the upper front surface and extending in the vertical direction, so that the pivot point of the swing arm 7 can be varied in the vertical direction. has been done. There are auxiliary links 16 on the left and right sides of the lower front surface of the rotary seat 5, respectively, with their base ends connected to the brackets 1.
7 and a support shaft 18 so as to be rotatable in the front-rear direction, and the tip of this auxiliary link 16 extends toward the center of rotation of the rotating seat 5 and connects the swing arm 7 in the vicinity of the center of rotation. It is rotatably coupled to approximately the midpoint by a support shaft 19. Therefore, when the swing arm 7 supported as described above is rotated, the auxiliary link 16
and guide rails 15 provide a specific movement trajectory. On the other hand, the clamp arm 8 disposed on the upper side has its base end near the rotation center line of the rotating seat 5, and is rotatably mounted on a support shaft 19 that connects the swing arm 7 and the auxiliary link 16. It is being

The above-described rotational operation of both arms 7 and 8 is performed by an arm actuating device composed of a clamp cylinder 20 and a swing cylinder 21. The base of the clamp cylinder 20 is rotatably mounted on a support shaft 14 that is a pivot point for the swing arm 7, and the tip of the piston rod 20a is pivoted by a pin 22 at a position slightly forward of the center of the clamp arm 8. has been done. Also. The base end of the swing cylinder 21 is rotatably mounted on the support shaft 18, which is the rotation fulcrum of the auxiliary link 16, and the tip of the piston rod 21a is pivoted by a pin 23 at a position slightly forward of the center of the swing arm 7. It is worn.

This embodiment is configured as described above,
The effect will be explained below.

In Figure 2, the radius R of the roll W is the swing arm 7.
This figure shows the most standard aspect of horizontal gripping when the distance from the tip of the rotating seat 5 to the center of rotation of the rotating seat 5 is smaller than the distance L. At this time, swing cylinder 2
1 has been reduced, and in this state swing arm 7
When the pad 9 is brought into contact with the lower surface of the roll W and the clamp cylinder 20 is extended, the clamp arm 8 rotates downward around the support shaft 19, and the pad 10 presses the upper surface of the roll W. Therefore, the roll W is gripped by both arms 7 and 8, but at this time, the tip of the clamp arm 8 is located in front of the tip of the swing arm 7, and the lengths are unequal, so that the roll W is not gripped laterally. Done properly.

FIG. 3 shows a state in which the roll W is gripped vertically. In this state, the clamp arm 8 and the swing arm 7 are adjusted to have the same length relationship, and the adjustment is made between the clamp cylinder 20 and the swing cylinder 21. This is done by selectively activating the .

When both arms 7 and 8 have changed to such a relationship of equal length, the roll center, which is the midpoint between the tips of both arms 7 and 8, has a roll radius R that corresponds to the rotation of rotating seat 5 from the tip of swing arm 7. Those whose distance to the center is smaller than L can be placed very close to the center line of rotation of the rotary seat 5, whether shown by solid lines or imaginary lines. Therefore, in such vertical gripping work, both arms 7 and 8
By making the rolls have equal lengths and placing the roll center near the rotation center line, it is possible to suppress the occurrence of load imbalance in the left-right direction and enable stable transportation. Therefore, when changing the above-mentioned arms 7 and 8 from a position of unequal length to a position of equal length, the roll center generally tends to be displaced beyond the rotation center of the rotary seat 5, that is, to become eccentric. However, in this roll clamp, the support shaft 14, which is the pivot point of the swing arm 7, is connected to the guide rail 1.
Since the structure is such that the swing arm 7 and the clamp arm 8 can be displaced via the rollers 13 while being guided by the rotating seat 5, when the swing arm 7 and the clamp arm 8 swing integrally to positions of equal length, the above-mentioned support shaft 14 moves toward the rotating seat 5. is displaced toward the rotation center line, and this displacement suppresses the eccentricity of the roll center toward the clamp arm 7 side with respect to the rotation center line as much as possible, thus improving the approach of the roll center to the rotation center line. It will be better.

Next, FIG. 4 shows a large diameter roll, that is, the roll radius R is from the tip of the swing arm 7 to the
This figure shows lateral grip when the distance to the center of rotation is greater than the distance L. In this case, the intermediate point between the tips of the arms 7 and 8, which are located at positions of unequal length, is slightly rearward of the roll center, and the roll W
Generally, the surfaces of pads 9 and 10 are made of a material with a high coefficient of friction, so as long as the roll W is made of newspaper or kraft paper, the pads will not hold. Sufficient gripping is possible with the frictional forces of 9 and 10.

Further, FIG. 5 shows a state in which both arms 7 and 8 are changed to positions of equal length and grip a large diameter roll W vertically. In this case, as in the case of vertically gripping the normal diameter roll W shown in FIG. The shaft 14 is displaced toward the rotation center line of the rotating seat 5. Therefore, the amount of swing of the ends of both arms 7 and 8 toward the clamp arm 8 side is
The amount of eccentricity of the roll center with respect to the rotation center line is suppressed to a small range, and as a result, the eccentric load in the left and right direction is small and stable transportation is possible. At the same time, the clamp arm 8 can be prevented from protruding outside the vehicle width.

As described in detail above, the present invention sets the pivot point of the swing arm at a position away from the center line of rotation of the rotating seat, and sets the pivot point of the clamp arm at a position close to the center line of rotation of the swing arm. In the two-axis roll clamp set in the section, the support shaft, which is the rotation fulcrum of the swing arm, is made movable in the radial direction of the rotating seat along a guide provided on the rotating seat, and is attached to the rotating seat. The structure is such that a specific movement trajectory is given to the swing arm by means of an auxiliary link. Therefore, according to the roll clamp of the present invention, by selectively rotating both arms, horizontal gripping work can be performed with the arms changed to relative positions of unequal length, and vertical gripping work can be performed with the arms changed to relative positions of unequal length. Of course, this can be carried out with both arms changed to the same length relationship position, but especially when both arms are changed to the same length relationship position for vertical gripping, the roll radius will rotate from the tip of the swing arm. For rolls with a range smaller than the distance to the rotation center line of the seat, the roll center is actively moved closer to the rotation center line, and for large diameter rolls whose roll radius exceeds the above distance, the roll center is moved closer to the rotation center line. The amount of eccentricity can be kept within a small range by minimizing deviation from the center line of rotation. This means that regardless of the diameter of the roll, the unbalanced load in the left and right direction during vertical gripping work can be reduced and stable transportation is possible, so this roll clamp is better than conventional roll clamps. This allows the range of roll handling to be expanded.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a perspective view showing a roll clamp, FIG. 2 is a side view showing a normal diameter roll in a horizontally gripping state, and FIG. 3 is a plan view similarly showing a vertically gripping state. FIG. 4 is a side view showing the large-diameter roll in a horizontally gripped state, and FIG. 5 is a plan view similarly showing the vertically gripped state. 1... Mast, 5... Rotating seat, 7... Swing arm, 8... Clamp arm, 13... Roller, 14... Support shaft, 15... Guide rail, 16
...Auxiliary link, 18, 19...Spindle, 20...
Clamp cylinder, 21...Swing cylinder,
W...Roll.

Claims (1)

[Claims] 1. A rotating seat that is rotatably attached to the lifting device in a vertical plane, a guide that is attached to the front surface of one side of the rotating seat that extends in the radial direction, and a base end that extends along the guide. a swing arm that is movably supported and whose tip extends forward on the other side across the center of rotation of the rotating seat; and a swing arm whose base end is pivoted at approximately the midpoint of the swing arm and whose tip is on one side of the rotating seat. A clamp arm extends forward and faces the tip of the swing arm, and one end is pivotally connected to the front surface of the other side of the rotating seat, and the other end is pivoted at approximately the midpoint of the swing arm in the vicinity of the rotation center line of the rotating seat. an auxiliary link that is attached to the swing arm to give the swing arm a specific motion trajectory; and an arm actuating device that includes a cylinder for the swing arm connected to the rotating seat and a cylinder for the clamp arm connected to the base of the swing arm. The above-mentioned two arms are rotated independently or integrally by the actuating device between an equal length position and an unequal length position with their tips facing each other at a predetermined interval, and the swing arm is A roll clamp for a forklift whose base end rotates around a pivot point with an auxiliary link while moving along a guide.