JP2006117343A - Rotary roll clamp device for cargo handling vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary roll clamp device for unloading a columnar work onto a predetermined position, while avoiding an impact on the work without disposing a rolling stop means such as a stopper to an unloading surface position, when unclamping the work in a transverse attitude with respect to the unloading surface. <P>SOLUTION: A rotation detecting means 7 detecting the rolling of the work 6 is disposed on a contact face side between the work 6 and a pad 44 attached to a tip of a long arm 43 of a pair of short and long clamp arms 4. During unclamping, detection of presence/absence of rotation by the rotation detecting means, and instructions for the long arm 43 to start/stop the unclamping operation are repeated. The release, stop, and release of the rolling of the work 6 are repeated to unload the work in an approximately static condition onto the unloading surface G. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotary roll clamp device for a cargo handling vehicle such as a forklift truck used for carrying and unloading various types of cargo, particularly cylindrical cargo such as roll paper.

  In recent years, unmanned forklift trucks have come to be used as cargo handling vehicles used for carrying, loading, and unloading loads (hereinafter referred to as workpieces). In particular, when performing a roll clamp handling operation on a cylindrical workpiece such as roll paper, a pair of open and close clamp arms that can be opened and closed for gripping the peripheral surface of the workpiece is attached to the front portion of the vehicle. The shorter short arm of the pair of clamp arms is fixed to the holder, and the longer long arm can be rotated with respect to the holder by the clamp cylinder, so that both arms can grip the peripheral surface of the workpiece. It has become.

  In this way, when loading and unloading a cylindrical workpiece using a pair of clamp arms, the workpiece is first loaded in a loading posture state (hereinafter referred to as a vertical posture state) in which the peripheral surface of the workpiece is orthogonal to the unloading surface. On the other hand, the peripheral surface is clamped from both sides in the radial direction, and while holding the work, the clamp arm is rotated 90 degrees around the horizontal axis so that the short arm is down, and the work's peripheral surface is parallel to the unloading surface. It is a general rotary roll clamp device that unclamps after a short arm is lowered to the unloading surface after being brought into a loaded posture state (hereinafter referred to as a horizontal posture state).

  In clamping and unclamping operations, conventionally, both arms are clamped by rotating them in the closing direction at the workpiece gripping position, and long using an angle sensor that detects the rotation angle of the long arm or a pressure sensor that detects the clamping cylinder pressure. The rotation state of the arm is detected, and when this angle or pressure reaches the specified clamp value, the clamp operation is completed, and then the arm is rotated and lowered 90 degrees at the unloading position. When it is determined that the short arm has touched the unloading surface, the lowering of the clamp arm is stopped, and then the long arm is released to the position where the workpiece is separated to start the unclamping operation, and the unclamp specified value is reached. When it reaches, the completion of the unclamping operation is determined (see, for example, Patent Document 1).

However, in the conventional rotary roll clamp device, when the cylindrical workpiece is unclamped in the horizontal posture, the short arm is in contact with the unloading surface, but it is not between the work peripheral surface and the unloading surface. A gap H corresponding to the thickness of the pad at the tip of the short arm that grips the workpiece is generated, and the lowermost surface of the workpiece is in a state of floating from the unloading surface.
In this way, when the long arm is opened and rotated until it reaches the unclamped specified value of the pressure sensor while the work is separated from the unloading surface, the work is no longer gripped by the long arm and the center of gravity of the work is pivotally attached to the tip of the short arm. The workpiece moves to the front side of the pivot point of the pad, tilts the pad forward, the work rolls down to the unloading surface side and rolls down on the unloading surface.
When a stopper is provided as a means to stop rolling so that the workpiece can be unloaded to a predetermined position on the unloading surface, it is costly and even if a stopper is provided, the workpiece will collide with the stopper and bounce off, receiving the impact and the workpiece May be damaged and may not stop in place due to rolling.

In the case of the prior art in which the unclamping of the long arm is controlled by the angle sensor, the long arm is released from the workpiece gripping angle (state) by a certain angle based on the unclamping prescribed value, and is temporarily stopped. The workpiece rolls when the gripping force of the clamp arm is released, and when the workpiece re-contacts with the long arm that is waiting at the open position, the workpiece is repeatedly stopped. While detecting, the angle was gradually increased to prevent the workpiece from rolling during loading.
Japanese Patent Laying-Open No. 2004-189376 (page 3-5, FIG. 2)

However, depending on the workpiece diameter, the height from the workpiece gripping position by the pad pivot point of the long arm tip to the top surface of the workpiece differs. Rolling can be stopped with a large-diameter workpiece, but the arm tip may stand by at a position above the top surface of the workpiece, that is, beyond the rolling area of the workpiece, so that contact cannot be made and rolling cannot be stopped sufficiently. There is.
Also, the positional relationship between the opening angle of the long arm and the beginning of rolling of the workpiece differs depending on the shift in the depth direction of the workpiece with respect to the long arm when gripping the workpiece. The work was also troublesome.

  The present invention has been made in view of the above problems, and the object of the present invention is to stop rolling of a stopper or the like at a predetermined position on an unloading surface when a cylindrical workpiece is unclamped in a horizontal posture. An object of the present invention is to provide a rotary roll clamp device for a cargo handling vehicle that enables unloading to a predetermined position while avoiding an impact on a workpiece without using means.

In order to achieve the above object, the invention according to claim 1 has a pair of long and short clamp arms that can be opened and closed to grip a cylindrical workpiece, and a workpiece whose peripheral surface is gripped by the clamp arm. When the clamp arm is unclamped by the release operation of the clamp arm with its peripheral surface parallel to the unloading surface, the upper arm of the pair of clamp arms is released at the tip of the long arm. A rotary roll clamp device for a cargo handling vehicle configured to temporarily stop at a position where the workpiece rolling to the surface side contacts, and rolling the workpiece to the tip side of the long arm and the contact surface side with the workpiece. Rotation detection means is provided to detect whether or not the workpiece is rolling by this rotation detection means, and start during unclamping operation for the long arm And performing repeatedly stop instruction.

According to the first aspect of the present invention, the long arm is rotated in the opening direction to release the clamping pressure on the workpiece to start the unclamping operation on the workpiece. Rolls forward with the pad unloaded and rotated to the surface side.
At this time, the rolling of the workpiece is directly detected by the rotation detecting means, the operation of the clamp cylinder for controlling the rotation of the long arm based on the signal from the detecting means is stopped, the opening operation of the long arm is temporarily stopped, and the work is also padded. The rolling comes to rest once in contact with. If the rotation detecting means detects that the workpiece is stationary, the long arm is rotated again in the opening direction, and a rotational force is generated on the workpiece, and then stop control is performed again.

  By repeatedly performing this long arm rotation control operation and the workpiece rotation control operation while confirming that the workpiece has started and stopped, the workpiece is placed on the unloading surface after the unclamping operation is started in the horizontal posture of the workpiece. By repeating the rolling-stop-rolling-stop of the workpiece itself before placing it, the workpiece is prevented from generating rapid rotational force.

  According to a second aspect of the present invention, in the rotary roll clamp device for a cargo handling vehicle according to the first aspect, the rotation detecting means is a rotation detection sensor capable of electrically detecting a relative movement between the pad or the long arm and the workpiece. It is characterized by being.

  According to a third aspect of the present invention, in the rotary roll clamp device for a cargo handling vehicle according to the second aspect, the rotation detection sensor is an encoder or a potentiometer.

  According to the second and third aspects of the present invention, the rotation presence / absence information of the workpiece is electrically detected by a rotation detection sensor such as an encoder or a potentiometer, such as a pulse signal or a voltage value signal, and the clamp pressure on the workpiece with respect to the long arm is detected. It is possible to stop the rolling of the workpiece by repeatedly giving and releasing instructions quickly.

  In the present invention, since the rolling of the workpiece can be directly detected, it is possible to repeatedly perform the rotation control operation of the long arm and the rotation control of the workpiece while confirming that the workpiece has started and stopped. By repeatedly rolling, stopping, rolling, and stopping the workpiece itself from the start of the unclamping operation in the placed posture to the placement of the workpiece on the unloading surface, the workpiece does not generate a rapid rotational force. It was placed on the unloading surface in a state of being kept in a substantially stationary state with a slight rolling, so that the impact and rapid rolling due to the falling of the workpiece could be avoided and the unloading to a predetermined position became possible.

(First embodiment)
Hereinafter, a rotary roll clamp device for a cargo handling vehicle according to a first embodiment will be described with reference to FIGS.
The rotary roll clamp device of this embodiment will be described in detail based on the case where it is adapted to an unmanned cargo handling vehicle.
A pair of left and right masts 1 mounted on the front of a cargo handling vehicle such as an unmanned forklift truck is provided with a rotating mechanism 2 of a rotary roll clamp device so as to be movable up and down along the mast 1.

  An arm holder 3 is fixed to the front surface of the rotating disk 2a of the rotating mechanism 2. The arm holder 3 has a pair of long and short that can be opened and closed to hold a load, in particular, a cylindrical roll paper 6 (hereinafter referred to as a work 6). The base end of the clamp arm 4 is attached. In general, the short arm 41 is fixed to the arm holder 3, and the long arm 43 is pivotally attached to the arm holder 3 by the clamp cylinder 5. In addition, pads 42 and 44 having curved shapes that can be slidably contacted with the outer peripheral surface of the workpiece 6 are pivotally attached to the tip of the clamp arm 4 (points S and T in the figure). The pads 42 and 44 are constantly urged outward (opening direction) via a leaf spring (not shown) or the like.

  The rotation drive control of the rotating mechanism 2, the opening / closing operation control of the clamp arm 4, and the loading / unloading work control such as the conveyance / loading / unloading of the workpiece are generally performed based on commands from the control device. When the clamp arm 4 grips the peripheral surface of the work 6, the line ST connecting the pivot points S and T of the pads 42 and 44 at the tips of the short arm 41 and the long arm 43 is the axis Q of the work 6. The work 6 is gripped so as to be held on the mast 1 side in the front side.

  In the figure, reference numeral 7 denotes rotation detection means, which is attached to the contact surface side of the pad 44 attached to the tip of the long arm 43 with the workpiece 6. The rotation detecting means 7 is in contact with the outer peripheral surface of the workpiece 6 in a constantly pressed state in a state where the clamp arm 4 holds the workpiece 6, and detects whether the workpiece 6 is rotated.

  The mounting position of the rotation detecting means 7 on the pad 44 is preferably in front of the pivot point T position of the pad 44. That is, by positioning the rotation detecting means 7 on the front side, its own weight is added to the front side of the pad 44 and acts slightly on the direction Z (gripping side) in which the front side of the pad 44 is tilted forward, and the rotation detecting means 7 and the workpiece Ensure contact with 6.

  Specifically, the rotation detection means 7 is an electrical rotation detection sensor that can detect the rolling due to the rotation of the workpiece 6 by contacting the workpiece 6 such as a rotary encoder that is detected by a pulse signal, and the workpiece 6 in this rotation detection sensor. The member in contact with the encoder is preferably a rubber disk 72 or the like coaxial with the encoder or the like. Further, the rubber disc 72 is supported coaxially with the pivot direction of the pad 44. Thus, when the clamp arm 4 is gripping the workpiece 6, the encoder or the like constantly monitors the rotation of the outer peripheral surface of the workpiece 6 in the X direction (work rotation presence / absence information), and sends information to the control device. Causes the clamp arm 4 to start and pause the unclamping operation according to the information.

Next, a horizontal roll clamping operation of a workpiece by the rotary roll clamping device for a cargo handling vehicle according to this embodiment will be described.
First, the long arm 43 is rotated in the opening direction Y by the clamp cylinder 5 so that the distance (ST) between the pads 42 and 44 at the tips of both clamp arms 4 is larger than the diameter of the workpiece 6. Thereafter, both the clamp arms 4 are rotated on the vertical surface by the rotation mechanism 2, and the vehicle is advanced so as to grip the workpiece in the vertically placed posture in which the peripheral surface of the workpiece to be gripped is orthogonal to the unloading surface G. Then, the pad 42, 44 is used to reach the position where the work 6 side peripheral surface can be gripped, and the long arm 43 is rotated in the gripping direction by the clamp cylinder 5 to grip the work 6.
After gripping the workpiece 6, the clamp device is once lifted, retracted from the loading place, and the clamp arm 4 is rotated again on the vertical plane by the rotating mechanism 2, and the workpiece 6 is rotated with respect to the unloading surface G. It is transported to the unloading place while being held in a horizontal posture, which is a parallel state.

  If it arrives at the unloading place, the rotating mechanism 2 is lowered along the mast 1 while holding the workpiece 6 in the horizontal posture, and the lower surface of the short arm 41 of the clamp arm 4 is brought into contact with the unloading surface G. At this time, even if the back surface of the pad 42 on the short arm 41 side is in contact with the unloading surface G, the lowermost surface of the work 6 is positioned above the unloading surface G by a gap H by the thickness of the pad 41 ( State shown in FIG.

  From this state, as shown in FIG. 4, the clamp cylinder 5 is operated to start the turning operation of the long arm 43 positioned on the upper side in the opening direction Y to perform the unclamping operation of the workpiece (step 1). If the long arm 43 is slightly rotated but the gripping pressure on the workpiece 6 via the pad 44 is loosened, the restraint of the workpiece 6 is released (step 2).

  When the gripping force of the workpiece 6 is loosened, the center of gravity of the workpiece 6 moves forward due to a deviation between the axis Q of the workpiece 6 and the pivot point S of the pad 42 on the short arm 41 side. The pad 42 of the arm 41 is tilted forward about the pivot axis, and the center of gravity of the work 6 is moved along with the forward tilting of the pad 42 so that a moment to roll on the pad 42 acts on the work 6. 6 starts rolling and rolls until it comes into contact with the pad 44 although it is a slight gap with the pad 44 on the long arm 43 side. This rolling is caused by rotating a rubber disc 72 which is a rotating body coaxial with the rotary encoder 7 constituting the rotation detecting means in contact with the surface of the workpiece 6 and immediately detected by the rotation detecting means 7 to be detected as rolling start detection information by the control device ( (Step 3) (state shown in FIG. 3B).

As soon as the rolling start detection information is input to the control device, a stop signal for rotating the clamp cylinder 5 in the opening direction Y of the long arm 43 is output, and the operation of the clamp cylinder 5 and the opening operation of the long arm 43 are temporarily stopped. (Steps 4 and 5) and the workpiece 6 comes into contact with the pad 44 on the long arm 43 side, and waits for the rolling movement of the workpiece 6 to stop.
If the temporary stop state of the workpiece 6 is confirmed by the presence or absence of rotation of the rotation detecting means 7, the rolling movement stop control of the workpiece 6 in step 5 is repeated from the start of the opening operation of the long arm 43 in step 1 again.

During the above-described unclamping operation, the rotation detecting means 7 repeatedly detects the presence or absence of rotation of the workpiece 6 and repeatedly stops and starts (unclamps) the opening operation (unclamping operation) for the long arm 43 to short-circuit the workpiece 6. The arm 41 is slowly rolled down from the tip of the pad 42 to the unloading surface G and is brought into contact with the pad 44 of the long arm 43 to be stationary on the unloading surface G.
Thereafter, the long arm 43 is fully opened (step 6), and the work 6 is placed without rolling on the unloading surface G by retracting the cargo handling vehicle (state shown in FIG. 3C).

The rotary roll clamp device for a cargo handling vehicle according to this embodiment has the following effects.
(1) The rotation detection sensor that constitutes the rotation detection means can detect the rotation of the workpiece by directly contacting it, and the detection information of the start and stop of the workpiece is sequentially output to indicate the presence or absence of the rotation. While confirming, the rotation control operation of the long arm and the rotation control operation of the workpiece can be repeatedly performed. Therefore, a rapid rotational force is generated in the workpiece by repeatedly rolling, stopping, rolling, and stopping the workpiece itself from the start of the unclamping operation in the horizontal position of the workpiece to the placement on the unloading surface of the workpiece. The workpiece can be placed on the unloading surface without being rolled and kept in a substantially stationary state by a slight rolling.

(2) Since the workpiece can be unclamped on the unloading surface in a substantially stationary state, it can be dropped from the pad gripping surface without having to provide a stopper to stop the rolling of the workpiece at a predetermined position on the unloading surface. It is possible to unload softly to a predetermined position while avoiding the impact due to impact and rapid rolling due to free rolling that is not constrained on the pad. The work can be moved to a predetermined position while avoiding impact damage to the work on the unloading surface. Unloading work can be performed in an orderly manner.

(3) Even if the workpiece diameters are different, the unclamp opening distance of the long arm to the workpiece may be such that a slight gap is formed between the pad and the workpiece where the gripping force on the workpiece is loosened. Rotating / stopping operation is detected by detecting the presence or absence of rolling of the workpiece, and the gap can be controlled, so that the pad is always in contact with the workpiece regardless of the workpiece diameter, and when the workpiece starts rolling The workpiece can come into contact with the workpiece and the rolling of the workpiece can be temporarily stopped. Therefore, the troublesome adjustment work for adjusting and controlling the arm angle depending on the workpiece diameter is eliminated.

The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist of the invention. For example, the following modifications may be made.
In the first embodiment, the explanation has been made based on the case where the unmanned forklift truck is equipped with the rotary roll clamp device. However, the unmanned forklift truck is not necessarily limited to the unmanned forklift truck.
A rotary encoder that detects a detection value by a rotation detection sensor that constitutes a rotation detection means is used as a pulse signal, but a potentiometer that detects a voltage value may be used.
○ The rotation detection sensor is attached to the front side of the pad pivot part of the pad on the long arm side, but it can be detected near the pad pivot part or the tip of the long arm as long as the workpiece can be detected during unclamping. good.

It is a side view of the rotary roll clamp apparatus which concerns on embodiment of this invention. It is a principal part side view which shows the relationship between the rotation detection means and pad of the rotary roll clamp apparatus which concerns on embodiment of this invention. It is explanatory drawing shown in steps of the unclamp operation state which concerns on embodiment of this invention. (A) is a figure which shows the state before the unclamp operation | movement which the short arm contacted the unloading surface. (B) is a figure which shows the state which open | released the long arm from the state of (a), and the workpiece | work rotated. (C) is a figure which shows the unclamped state by which the workpiece | work was mounted in the stationary state on the unloading surface. It is a flowchart figure which shows the unclamp control procedure at the time of the unclamp action | operation which concerns on embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mast 2 Rotation mechanism 3 Arm holder 4 Clamp arm 41 Short arm 42, 44 Pad downstream pipeline 43 Long arm 5 Clamp cylinder 6 Work piece 7 Rotation detection means (rotation detection sensor, rotary encoder, potentiometer)
71 Support shaft 72 Rubber disk G Unloading surface H Clearance Q Axes S and T of work 6 Pivoting points of pads 42 and 44 with long and short arms

Claims (3)

The clamp arm has a pair of long and short clamp arms that can be opened and closed to grip a cylindrical workpiece, and the clamp arm has a peripheral surface held parallel to the unloading surface. When the unclamping operation is performed, the opening operation of the upper long arm of the pair of clamp arms is temporarily stopped at the position where the workpiece that rolls to the unloading surface side contacts the tip of the long arm. A rotary roll clamp device for a cargo handling vehicle configured to be configured to provide a rotation detection means for detecting the rolling of a workpiece on a tip side of the long arm and on a contact surface side with the workpiece, and the rotation detection means A cargo handling vehicle characterized by detecting the presence or absence of rolling and repeatedly instructing start and stop of an unclamping operation for a long arm Rotary roll clamp device. 2. The rotary roll clamp device for a cargo handling vehicle according to claim 1, wherein the rotation detection means is a rotation detection sensor capable of electrically detecting a relative movement between the pad or the long arm and the workpiece. The rotary roll clamp device for a cargo handling vehicle according to claim 2, wherein the rotation detection sensor is an encoder or a potentiometer.

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