JPH0720840B2 - Roll-clamping method for industrial vehicles - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for unloading a roll clamp in an industrial vehicle.

[Prior Art] Generally, a roll clamp is used as an attachment for transporting a cylindrical load such as roll paper in an unmanned forklift. That is, as shown in FIGS. 12 (a) to 12 (c), the long arm 41 is rotated inward while the clamp C is gradually approaching the load L by the movement or reach operation of the vehicle. Arm 41 and fixed short arm 42
The load L is gripped by the inner surfaces of and. And clamp C
And the load L is conveyed to a predetermined load storage location.

[Problems to be Solved by the Invention] However, since the load L is grasped at two points of the long arm 41 and the short arm 42 in the above-mentioned forklift, the centers of the load L and the clamp C are preliminarily aligned with each other. There is a need. In this work, the center of the load L detected by a position sensor or the like is made to coincide with the center line of the clamp C, but it is difficult to detect the center of each load L when there are various roll diameters. When a detection error occurs, it becomes impossible to pick up the goods.

Further, it is necessary to separate the load L1 adjacent to the load L from the rotation locus of the long arm 41 so as not to interfere with the long arm 41 that rotates during the load pickup. There is room for improvement.

The present invention has been made to solve the above-mentioned problems, and an object thereof is to effectively utilize a space at a luggage installation place and eliminate the need for center alignment between a clamp and a luggage. The object of the present invention is to provide a method for taking loads by a roll clamp in an industrial vehicle that can reliably perform the above.

[Means for Solving the Problems] In order to solve the above-mentioned object, a first invention of the present application is a roll clamp unloading method in an industrial vehicle in which a pair of clamp arms holds a load at a predetermined unloading position. , Open both clamp arms and move them linearly to the load side, and move both clamp arms after the load contacts the bodywork part that is hung between them at the deepest part. Is stopped, and after the clamp arm is stopped, the clamp arm is linearly moved in the closing direction to grip the load.

Further, the second invention of the present application is a roll clamp unloading method in an industrial vehicle in which a pair of clamp arms grips a load at a predetermined unloading position, and both clamp arms are opened to linearly move forward to the load side. And detecting that a load has come into contact with the body part mounted between the two clamp arms at the innermost portion, and stopping the forward movement of both clamp arms after the detection operation. When,
After the stopping operation, both clamp arms are linearly moved in the closing direction, and the pressure applied to both clamp arms at the time of the closing is detected, and when the pressure reaches a predetermined value, the closing operation of the clamp arms is performed. It consists of stopping.

[Operation] In the first invention of the present application, both clamp arms are opened and linearly moved forward to the load side, and the load comes into contact with the bodywork section mounted between the clamp arms at the innermost portion. After that, by stopping the movement of both clamp arms and linearly moving both clamp arms in the closing direction, the clamp arms move within a small movement range, and the load is transferred to the connecting plate and the inner surface of each clamp arm. Holds at three points.

Further, in the second invention of the present application, the clamp arm moves within a narrow range as in the first invention. Then, when the pressure applied to both clamp arms reaches a predetermined value when the clamp arms are closed and the clamp arms securely grasp the load, the clamp arm is closed to stop the load inside the connecting plate and each clamp arm. Support at three points on the side.

[Embodiment] An embodiment in which the present invention is embodied in a roll clamp for an unmanned forklift truck will be described in detail below with reference to FIGS.

In FIG. 4, masts 2 are erected on a pair of leg portions 1 (only one is shown) horizontally projecting forward from the front portion of the forklift, and the mast 2 is extended along the leg portion 1 by expansion and contraction of the reach cylinder 3. Be moved back and forth. A support plate 4 is attached to the mast 2, and a base plate 6 of a clamp device 5 is supported on the mast 2 via a connecting mechanism 7 including a bracket and a shaft. The clamp device 5 is moved up and down together with the support plate 4 by winding the chain along with the expansion and contraction of the lift cylinder 8 extending parallel to the mast 2. When the forklift arrives just before the unloading position, the forklift is held in the illustrated posture, the pickup coil detects the electromagnetic induction wire, and the unloading is performed to grasp the load such as the roll paper P (Figs. 5 to 8). Drive at a slight speed toward the position.

The clamp device 5 will be described with reference to FIGS. 1 to 3. A hollow fitting portion 9b is formed at the rear ends of the main bodies 9a of the pair of clamp arms 9 spaced apart from each other in the vehicle width direction. Two upper and lower mounting plates 10 are provided on a rear mounting wall 11 so as to extend inward, and a pair of inner and outer rollers 12 are mounted on each mounting plate 10. Further, on the front surface of the base plate 6, two upper and lower guide rails 13 each having a channel shape in cross section and extending in the entire width direction are provided so as to face each other and open, and the center of the upper surface of the uppermost guide rail 13 is provided. A step portion 13a is formed in the portion. The rollers 12 of the clamp arm 9 are rotatably held in the guide rails 13, and a fitting portion 9b is slidably capped on the uppermost guide rail 13.

A pair of upper and lower clamp cylinders 15 are mounted on the front surface of the base plate 6 via cylinder brackets 15a on the opposite sides in the width direction, and each cylinder rod 16 is attached to a mounting plate 10 of a different arm 9 on the cylinder bracket.
It is attached via 16a (Fig. 4).

These clamp arms 9 are in the closed position shown by the solid line when the clamp cylinder 15 contracts and the fitting portion 9b is in contact with the step portion 13a. Then, when the clamp cylinder 15 projects, the roller 12 rolls outward in the guide rail 13, the fitting portion 9b shifts outward, and the clamp arm 9 moves to the open position indicated by the chain double-dashed line.

A contact wall U is fixed to the front end surface of the middle guide rail 13, and a seat surface 20 made of a vertically long rectangular elastic material is attached to the front surface of the contact wall U. Both mounting walls with both clamp arms 9 in the closed position
The inner end surface of 11 has reached the vicinity of both sides of the contact wall U. The rib portion 21 inside the base end portion of one clamp arm 9 has a mounting wall.
A pair of upper and lower light projecting elements 22 are provided slightly in front of 11, and a load receiving sensor 23 composed of a pair of light receiving elements is provided on the rib portion 21 of the other clamp arm 9 so as to face these. The light passage from the light projecting element 22 to the load receiving sensor 23 is set slightly forward of the surface of the sheet surface 20, and when the roll paper P comes into contact with the sheet surface 20 to the load receiving sensor 23 as shown in FIG. Is blocked.

Further, an opening sensor 24, which is a reel sensor using a potentiometer, is provided in the hollow portion H above the one clamp arm 9. Seating surfaces 25 made of the same material as the seating surface 20 are attached to the central portions in the lengthwise direction of both clamp arms 9, and above the seating surfaces 25, a known construction is provided as shown in FIG. A proximity switch 26 is provided. Both clamp arms 9 have a linear shape that becomes thinner toward the front in a plan view, and extend obliquely so as to approach each other toward the front.

Next, the electrical configuration of this embodiment will be described with reference to FIG.

When the light from the light projecting unit 22 is blocked by the roll paper P, the load receiving sensor 23 detects this and outputs this detection signal to the controller 29. The opening amount sensor 24 detects the opening amount of the clamp arm 9 from time to time and outputs this detection signal to the controller 29. Proximity switch 26 is clamp arm 9
When the roll paper P comes into contact with the inner surface of the paper, it is detected and the detection signal is output to the controller 29. The clamp pressure sensor 30 detects the pressure in the clamp cylinder 15 and outputs this detection signal to the controller 29.

The controller 29 drives the cargo handling motor 32 and operates the cargo handling hydraulic pump in accordance with a cargo handling program stored in advance at the time of cargo handling work such as unloading and loading, and from the end of the same cargo handling work to the start of the next cargo handling work. The cargo handling hydraulic pump is stopped without driving the cargo handling motor 32.

The controller 29 controls the electromagnetically controlled reach control valve 33 to open and close, expands and contracts the reach cylinder 3 to move the clamp device 5 forward and backward together with the mast 2, and holds the reach cylinder 3 so that it cannot expand and contract. Is held immovably in its position. Similarly, the controller 29 controls the opening and closing of the electromagnetically controlled lift control valve 34 to extend and retract the lift cylinder 8 to raise and lower the clamp device 5, and
Holding the lift cylinder 8 so that it cannot expand and contract, the clamp device 5
Is held so that it cannot be moved up and down.

The controller 29 controls the opening and closing of the electromagnetically controlled clamp control valve 35 to expand and contract the clamp cylinder 15 to open and close the clamp arm 9, and to hold the clamp cylinder 15 non-expandable to bring the clamp arm 9 to a constant opening amount. Hold.

When the controller 29 recognizes that the roll paper P comes into contact with the contact wall U of the clamp device 5 according to the signal from the load receiving sensor 23, it drives the clamp control valve 35 to extend the clamp cylinder 15 to the maximum (FIG. 7). ).

The controller 29 calculates the opening amount of the clamp arm 9 at each time according to the signal from the opening amount sensor 24, and when the opening amount reaches a predetermined value α (= d + 50 cm, FIG. 7) at the time of closing, the clamp control valve 35 is turned on. It controls and reduces the opening. It should be noted that d is the diameter of the roll paper P, and is input to the controller 29 in advance before each load taking operation.

The controller 29 confirms that either or both of the inner surfaces of the clamp arms 9 contact the roll paper P according to the signal from the proximity switch 26 (FIG. 9).

The controller 29 calculates the pressure in the clamp cylinder 15 based on the signal from the clamp pressure sensor 30. When both clamp arms 9 continue to grip the roll paper P for a certain period of time (FIG. 8), the pressure in the clamp cylinder 15 is increased by the force applied to the clamp arms 9 and exceeds the predetermined value β. Then, the controller 29 drives the clamp control valve 35 to switch to the closed position.

Now, the operation of the clamp control device configured as described above will be described below with reference to FIG.

Now, the forklift reaches the position just before the unloading position with the clamp arm 9 emptied and stops, and the controller drives the control valves 33 to 35 in accordance with the unloading program stored in advance to operate the corresponding cylinders 3, 8, 15 The clamp device 5 is held under the mast 2 as shown in FIG. 4, and both clamp arms 9 are opened to the maximum. After that, as the reach cylinder 3 extends, the mast 2, that is, the clamp arm 9 is advanced to the roll paper P side.

Then, in accordance with the reach operation, both clamp arms 9 advance on both sides of the roll paper P, and in step 1, the load receiving sensor
When the contact of the roll paper P with the sheet surface 20 is detected by the block 23 of the light reception, the controller 29 stops the extension of the reach cylinder 3 in step 2 to stop the reach operation. Next, in step 3, the controller 29 switches the clamp control valve 35 in the closing direction of the clamp arm 9, and in step 4, drives the cargo handling motor 32 to operate the cargo handling pump.

Then, the controller 29 constantly calculates the opening amount of the clamp arm 9 to be closed based on the signal from the opening amount sensor 24, and in step 5, this opening amount 1 is the predetermined amount α (= d
(+50 cm), the opening of the clamp control valve 35 is reduced in step 6 to decrease the closing speed of the clamp arm 9. Thereafter, when the controller 29 detects in step 7 that the roll paper P has contacted the clamp arm 9 by a signal from one (or both) of the proximity switches 26, the controller 29 detects from both clamp pressure sensors 30 in step 8. It is confirmed that the pressure values in both clamp cylinders 15 have exceeded the predetermined value β based on the signal of (1), and the process proceeds to step 9.

The controller 29 detects the clamp control valve in step 9.
35 is driven and closed, the clamp arm 9 is held so that it cannot be opened and closed, and the driving of the cargo handling motor 32 is stopped in step 10.

As described above, in the present embodiment, both clamp arms 9 are opened by a predetermined amount and moved forward, and when the roll paper P relatively moves between the clamp arms 9 to the position in contact with the contact wall U,
Both clamp arms 9 are closed. Then, the roll paper P
When the centerlines of the clamp device 5 and the clamp device 5 coincide with each other, the roll paper P is reliably gripped by the contact wall U and the inside of the clamp arm 9 by closing both clamp arms 9.

Further, when the roll paper P is placed in a wrong place and the center line of the roll paper P does not coincide with the center line of the clamp device 5, as shown in FIG. Is pushed by the clamp arm 9 moving in the closing direction, moved to the other clamp arm 9 side, and abuts on the inner side surface of the one clamp arm 9. Similarly to the one clamp arm 9, the other clamp arm 9 also moves by the same amount in opposition to the other clamp arm 9, so that the center line of the roll paper P contacting the inner side surfaces of both clamp arms 9 and the clamp device. When the center line of 5 coincides, reliable unloading is performed.

Further, the clamp arm 9 is provided linearly, and is moved horizontally to the roll paper P side in accordance with the reach operation, the forward movement of the vehicle, etc., and then is horizontally moved inward, that is, closed. Unlike the conventional product that rotates the, the range of movement is extremely narrow, and interference of the clamp arm 9 with the adjacent roll paper P is avoided.

It should be noted that the present invention is not limited to the above-described embodiment, and any modification such as embedding a pressure sensitive sensor in the seat surface 20 in place of the load receiving sensor 23 is, of course, possible.

[Effects of the Invention] As described in detail above, the first and second inventions of the present application make effective use of the space at the luggage installation location and eliminate the need for center alignment between the clamp and the luggage. It has an excellent effect that it can be surely performed.

[Brief description of drawings]

FIG. 1 is a plan view of a clamp device according to the present invention, and FIG.
The figure is a side view of one clamp arm, FIG. 3 is an exploded perspective view showing a clamp device, FIG. 4 is a side view of a forklift, FIG. 5 is a plan view showing a proximity switch, and FIG. 6 is a load clamp device. A plan view showing a state in which the connection member of FIG.
FIG. 7 is a plan view showing the relationship between the diameter of the load and the opening amount of the clamp arm, FIG. 8 is a plan view showing the state in which the load is supported by the clamp device at three points, and FIG. 9 is the load and the clamp device. Fig. 10 is a plan view showing a method for taking a load when the center lines of Fig. 11 do not match, Fig. 10 is a block circuit diagram showing the electrical configuration of the present invention, Fig. 11 is a flow chart showing the operation of the controller, and Fig. 12 (a) to Fig. 12 (a)- (C) is a top view which shows the load taking method in a conventional product one by one. The clamp arm 9, the contact wall U as a body part, and the load P.

Claims (2)

[Claims] 1. A roll clamp unloading method in an industrial vehicle in which a pair of clamp arms holds a load at a predetermined unloading position, wherein both clamp arms are opened and moved linearly to the load side. After stopping the movement of both clamp arms after the load comes into contact with the bodywork part hung between them at the innermost part of both clamp arms, and after the clamp arms are stopped, the clamp arms are closed. The method of picking up a load by using a roll clamp in an industrial vehicle, which comprises linearly moving in the direction and gripping the load. 2. A roll clamp unloading method for an industrial vehicle in which a pair of clamp arms hold a load at a predetermined unloading position, wherein both clamp arms are opened and moved linearly forward. And detecting that a load has come into contact with a body part mounted between the clamp arms at the innermost part, and stopping the forward movement of both clamp arms after the detection operation, Linearly moving both clamp arms in the closing direction after the stopping operation, and detecting the pressure applied to both clamp arms at the time of closing,
When the pressure reaches a predetermined value, the closing operation of the clamp arm is stopped.