JPH07196300A - Container spreader device - Google Patents

Abstract

PURPOSE:To provide a container spreader device which is effective in lessening an impact at the time of stopping extensible rails from moving. CONSTITUTION:A container spreader device comprises a pair of right and left extension/contraction rails 14, 16 installed to be movable in lateral direction and a driving device for moving the extension/contraction rails in lateral direction. Accordingly, it includes first sensing means 68, 70, 72, 74 for sensing approach to an end of the contraction course and emitting the sensing signal, a control device 80 for decreasing the extension/contraction speeds of the extension/contraction rails on the basis of either sensing signals via driving device, and a release means for releasing the decreasing control.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telescopic container spreader device mounted on a cargo handling vehicle such as a forklift and used for cargo handling of a container, and more particularly, to control a telescopic movement speed of a telescopic rail in the container spreader device. Regarding

[0001]

2. Description of the Related Art Generally, a container spreader device is attached to an elevating member such as a lift bracket or a finger bar of a forklift truck and used for loading and unloading containers. That is, such a container spreader device has a spreader body attached to the elevating member, and includes a rail holder formed in a horizontally long rectangular tube shape on the front side of the spreader body. In the rail holder, telescopic rails, which consist of a pair of left and right and have twist lock pins at their ends, are arranged so as to be telescopically movable. Accordingly, the telescopic rail can be telescopically moved according to the size of the container, and the twist lock pins can be engaged with the fishing holes formed at both ends of the upper surface of the container so that the container can be supported and transported. It has become.

The extension and contraction movement of the telescopic rail is
Each is a small piece-shaped stopper provided on the holder side,
Braking is performed by contact with a small-piece-shaped stopper receiver provided at a position facing the stopper on the telescopic rail side, and as a result, the movement of the telescopic rail is forcibly stopped. After that, by operating a lever that controls the movement of the telescopic rail provided in the driver's seat, the movement of the telescopic rail will be completely stopped. The distance between the twist lock pins at the maximum extension and the maximum contraction of the telescopic rail obtained by these stoppers is adapted to match the distance between the hanging holes of two standard containers, large and small. As such a container spreader device, an actual Kaihei 1-174
The container spreader device disclosed in Japanese Patent No. 398 can be mentioned.

[0003]

By the way, the expansion / contraction of the telescopic rail is performed at a very high speed in order to speed up the work of container loading and unloading. The stopper that comes into contact with it receives a large impact. As a result, the stopper itself may be deformed due to wear or damage, or the stopper setting position may be displaced, and the distance between the twist lock pins obtained by this stopper and the standard hanging hole of the container However, there is a problem in that it is not possible to maintain a match with the distance in (1), which hinders the cargo handling of the container.
Further, there remains a problem that the impact when the movement of the telescopic rail is stopped is one of the causes of the failure of various instrumentation components arranged in the container spreader device. Therefore, the present invention, in view of the above problems,
It is a technical problem to be solved to provide a container spreader device which is effective in alleviating the impact when stopping the movement of the telescopic rail.

[0004]

In order to achieve the above-mentioned object, the present invention provides a rail holder installed on a spreader main body with a twist lock pin that engages with a fishing hole of a container attached to the left and right sides. In a container spreader device in which a pair of telescopic rails are movably profitable in the lateral direction, and further, a drive device for moving the telescopic rails in the lateral direction is disposed in the rail holder, in the extension movement of the telescopic rails, the extension stroke ends. A first detecting means for detecting an approach and issuing a detection signal, and a second detecting means for detecting an approach to the end of the contraction stroke in the contraction movement of the telescopic rail and a second detection signal.
Detecting means, a control device for reducing the extension / contraction movement speed of the extension / contraction rail via the drive device based on a detection signal from the first detection means or the second detection means, and the extension / contraction rail by the control device. The gist of the present invention is to include a releasing means for releasing the reduction control of the expansion / contraction moving speed.

[0005]

In the container spreader device configured as described above, when the telescopic rail approaches the end of the extension stroke in the extension movement, the first detecting means detects the approach of the telescopic rail, and An output signal is issued to the control means for controlling the expansion / contraction speed to be reduced. And
The control means reduces the extension moving speed of the telescopic rail based on the output signal. Therefore, the extension speed of the telescopic rail is reduced at the end of the extension stroke. Similarly, when the telescopic rail approaches the end of the contraction stroke during the contracting movement, the second detecting means detects the approaching of the telescopic rail, and outputs an output signal to the control means for reducing and controlling the telescopic moving speed of the telescopic rail. Emit. And this control means
The contraction movement speed of the telescopic rail is reduced based on the output signal. Therefore, the contraction movement of the telescopic rail decreases at the end of the contraction stroke. Then, the releasing means releases the reduction control of the extension / contraction movement speed of the extension / contraction rail and prepares for the extension / contraction rail to be capable of extension / contraction operation at a high speed when starting the extension / contraction operation of the next extension / contraction rail.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the container spreader device according to the present invention will be described below with reference to FIGS. First, an outline of a telescopic container spreader device will be described with reference to FIGS. 1, 2 and 3. The container spreader device 1 is generally mounted on an elevating member 3 including a lift bracket, a finger bar and the like of a forklift 2 as shown in FIG. Then, as shown in FIG. 1, the container spreader device 1 includes a spreader body 10 in which pillar members are combined in a vertically long substantially rectangular shape so as to be fixed to the front side of the elevating member 3. A hollow rail holder 11 formed in a horizontally long rectangular tube shape is attached to a front side portion of the spreader body 10.
A pair of left and right telescopic rails 14 and 16 are provided therein so as to be telescopically movable. These telescopic rails 14, 16
Are substantially L-shaped, and have arm portions 14a and 16a that slide in the rail holder 11, and column portions 14b and 16b that are bent and extend at right angles from the respective tips of the arm portions 14a and 16a.
And extension portions 14c and 16c that extend short in the front horizontal direction at the tops of the pillar portions 14b and 16b. Furthermore, twist lock pins 14d and 16d that can be engaged with fishing holes formed at both ends of the upper surface of the container C are provided on the lower side surfaces of the extending portions 14c and 16c so as to hang down. The arms 14a, 16a
Each has a hollow shape with a substantially rectangular cross section, and the arm portion 16a enters into the arm portion 14a when the telescopic rails 14 and 16 are contracted.

Next, based on FIG. 2, telescopic rails 14, 1
A drive device for expanding and contracting 6 will be described. The chain sprocket 2 is provided at both end positions on the rear surface of the rail holder 11 which supports the telescopic rails 14 and 16 so as to be telescopically movable.
0 and 22 are rotatably attached. One of the chain sprockets 20 transmits the drive of the hydraulic motor 24 because the shaft at the center of the chain sprocket 20 is connected to the output shaft of the hydraulic motor 24 that can rotate in both forward and reverse directions. Between the chain sprockets 20 and 22, chains 30 and 32, which are divided into two by interposing two connecting pieces 26 and 28, are stretched in a circuit form in series. That is, the chain 30 is suspended on the chain sprocket 20, and the chain 32 is suspended on the chain sprocket 22.
Each end of 32 is connected by connecting pieces 26 and 28. The two connecting pieces 26 and 28 are slidably supported on the back surface of the rail holder 11 and are substantially parallel to the arm portions 14a and 16a of the telescopic rails 14 and 16 and are horizontally long rail driving rods. One end of each of 34 and 36 is fixed, and the other ends are fixed to the lower sides of the pillar portions 14b and 16b of the telescopic rails 14 and 16, respectively.

Therefore, when the hydraulic motor 24 is driven to rotate, the chain sprocket 20 rotates and the chain 30 moves.
Is driven and the chain 32 is driven via the connecting pieces 26 and 28 to rotate the chain sprocket 22. Then, along with these rotational movements, the connecting piece 2
Since the rails 6 and 28 move in the longitudinal direction of the rail holder 11, that is, the left-right direction in FIG.
Similarly, 6 is moved in the longitudinal direction of the rail holder 11, that is, in the left-right direction in FIG. As a result, the telescopic rail 14,
16 can be moved in the longitudinal direction of the rail holder 11, that is, the horizontal direction in FIG.

That is, when the hydraulic motor 24 rotates clockwise, the rotation of the chain sprocket 20 causes
The chain 30 drives the connecting piece 28 so as to pull it to the left in FIG. The chain 32 is driven by the towed connecting piece 28 to drive the chain sprocket 2
While rotating 2, the connecting piece 26 is pulled rightward in FIG. Therefore, the rail driving rod 36 moves to the left in FIG. 2 as the connecting piece 28 moves to the left in FIG. 2, and the rail driving rod 36 moves to the right in FIG. 2 as the connecting piece 26 moves to the right. 34 will move to the right in FIG. As a result, the telescopic rails 14 and 16 are driven to contract and move.

Similarly, when the hydraulic motor 24 rotates counterclockwise, the chain 30 drives the connecting piece 26 to be pulled to the left in FIG. 2 through the rotation of the chain sprocket 20. The chain 32 is driven by the pulled connecting piece 26 to rotate the chain sprocket 22, and the connecting piece 28 is pulled rightward in FIG. Therefore, the rail driving rod 34 moves to the left in FIG. 2 as the connecting piece 26 moves to the left in FIG. 2, and the rail driving rod 34 moves to the right in FIG. 2 as the connecting piece 28 moves to the right. 36 is shown in FIG.
It will move to the right in. As a result, the telescopic rails 14 and 16 are driven so as to extend and move.

Next, the braking and stopping of the telescopic movement of the telescopic rails 14 and 16 will be described below with reference to FIGS. 1 and 2. As shown in FIG. 2, the rail driving rods 34, 3
In FIG. 6, thin vertically elongated stoppers 40 and 42 having a substantially rectangular parallelepiped shape are provided at the respective ends to which the connecting pieces 26 and 28 are attached. And, on the back surface of the rail holder 11,
Two small piece-shaped stopper receivers 44 and 46 are provided at positions facing the stoppers 40 and 42 and near the chain sprockets 20 and 22, respectively. It should be noted that the stopper receivers 44 and 46 are disposed between the rail driving rod 3 and
4, 36 and the chains 30, 32 are divided into two because of the clearance required to move. Therefore, as the telescopic rails 14 and 16 continue to extend, the stopper 4
0 and 42 come into contact with the stopper receivers 44 and 46, and the extensional movement of the telescopic rails 14 and 16 is forcibly stopped. Therefore, the stoppers 40, 42
By the stopper receivers 44 and 46, the telescopic rail 1
A maximum extension distance of 4, 16 is determined.

Further, as shown in FIG. 1, the telescopic rail 1
In the lower part of the inner side surface of the pillar portions 14b and 16b of 4, 16 at the most front side, a thin vertically elongated stopper 50 having a substantially rectangular parallelepiped shape,
52 is provided. Further, at the frontmost ends of both ends of the rail holder 11, stoppers 54 and 56, which are also thin and vertically long and have a substantially rectangular parallelepiped shape, are provided at positions facing the stoppers 50 and 52, respectively. Therefore, as the telescopic rails 14 and 16 continue to contract and move, the stopper 5
0, 52 and the stopper receivers 54, 56 come into contact with each other, and the contraction movement of the telescopic rails 14, 16 is forcibly stopped. Therefore, the maximum contraction distance of the telescopic rails 14 and 16 is determined by the stoppers 50 and 52 and the stopper receivers 54 and 56.

As described above, the telescopic rails 14 and 16 are
After the telescopic movement of the vehicle is forcibly stopped by the stoppers 40, 42, etc., the telescopic rail 1 installed in the driver's seat
The levers that control the movements of 4 and 16 are telescopic rails 14 and 1.
Operate so that 6 stops. As a result, the movement of the telescopic rail can be stopped completely. In addition, the stopper 4
The distance between the twist lock pins 14d and 16d at the maximum extension and the maximum contraction of the telescopic rails 14 and 16 determined by the maximum extension and contraction distances of the telescopic rails 14 and 16 obtained by 0, 42, etc. It is adapted to match the distance between the hanging holes of two standard containers C.

Further, as shown in FIG. 1, the rail holder 1
A non-contact type proximity switch 60 and a non-contact type proximity switch 62 are provided at both ends of the upper surface of the telescopic rail 1. The telescopic rail 1 is located at a position facing the proximity switches 60 and 62.
Dogs 64 and 66 are provided on the inner side surface portions of the pillar portions 14b and 16b of Nos. 4 and 16, respectively. Therefore, the telescopic rail 1
When 4 and 16 continue the contraction movement and reach the maximum contraction distance,
The proximity switches 60 and 62 detect the approach of the dogs 64 and 66. Then, based on a circuit configuration (not shown), it is displayed on the operation panel (not shown) that the telescopic rails 14 and 16 have reached the maximum contraction distance. Normally, the operator operates the levers that control the movement of the telescopic rails 14 and 16 so that the telescopic rails 14 and 16 stop based on the display on the operation panel. Although not shown, similar proximity switches and dogs are provided on the rear surface of the rail holder 11, and the arrival of the maximum extension distance of the telescopic rails 14 and 16 is displayed on the operation panel (not shown) of the driver's seat. It is like this.

With further reference to FIG. 2, the container spreader apparatus according to the present embodiment is provided with proximity switches 68, 70 and dogs as first detecting means for detecting that the telescopic rails 14, 16 are approaching the end of the extension operation. 72, 74,
Proximity switches 68 and 70 and dogs 76 for detecting that the telescopic rails 14 and 16 have approached the end of the contraction operation,
And 78. Furthermore, the arrow line IV-I in FIG.
As will be understood with reference to FIG. 4, which is a schematic cross-sectional view taken along V, the proximity switches 68, 70 are provided on the rail holder 11, and the dogs 72, 74 are respectively provided on the telescopic rail 1.
The arms 16a are attached to the proximity switches 68 and 70 in the vicinity of the ends of the extension strokes 4 and 16 so as to face the proximity switches 68 and 70, respectively. On the other hand, each of the dogs 76 and 78 near the end of the contraction stroke of the telescopic rails 14 and 16 faces the respective proximity switch 68 and 70 so as to face the arm 16a.
Is attached to.

Dogs 72, 76 for the proximity switch 70
Is formed longer than the dogs 74 and 78 for the proximity switch 68, and extends in the longitudinal direction of the arm 16a. More specifically, the dogs 72 and 76 detect the dog 72 near the end of the extension stroke of the telescopic rails 14 and 16 faster than the proximity switch 68 detects the dog 74 and the telescopic rails. 14, 1
In the vicinity of the end of the contraction stroke of 6, the proximity switch 68 detects the dog 76 faster than the proximity switch 68 detects the dog 78.

The proximity switches 68 and 70 are used for the hydraulic motor 2
4 is connected to the control means 80. When the proximity switch 68 detects the dogs 72 and 76 near the end of the expansion or contraction stroke of the telescopic rails 14 and 16, the proximity switch 68 generates a detection signal to the control means 80. Similarly, when the proximity switch 70 detects the dogs 74 and 78 near the ends of the expansion or contraction strokes of the telescopic rails 14 and 16, it outputs a detection signal to the control means 80. As the proximity switches 68 and 70, generally available seasonal switches of electrostatic induction type or magnetic type can be used. Alternatively, a contact type proximity switch having a whisker-like sensation may be used.

Next, referring to FIGS. 5 and 6, the hydraulic motor 24
The control means 80 for will be described. As will be understood from FIG. 5, the control means 80 has a hydraulic circuit 80a for the hydraulic motor 24 and an electric circuit 82 for driving the solenoid of the solenoid type shutoff valve provided in the hydraulic circuit 80a. It is equipped and configured. In FIG. 5, the hydraulic circuit 80a includes a hydraulic pump 801 as a hydraulic source for supplying pressurized hydraulic oil to the hydraulic motor 24. In FIG. 5, the hydraulic pump 801 is connected to the engine 84 of the cargo handling vehicle in which the spreader device 1 is mounted.

The hydraulic pump 801 is connected to a solenoid type shutoff valve 805 via a pipe line 802. The shut-off valve 805 is selectively operated between open and closed by controlling the operation of the solenoid 814 by an electric circuit for driving a solenoid (hereinafter, simply referred to as a solenoid drive circuit) 82 described below. Further, the pipe line 802 is connected to the throttle valve 807 via the branch pipe line 806, and the shutoff valve 8
05 and the throttle valve 807 are connected in parallel relationship. The throttle valve 807 may be a simple orifice. That is, the throttle valve 807 may be any means that can reduce the hydraulic oil supplied to the hydraulic motor 24. The hydraulic oil supplied to the hydraulic motor 24 is supplied to the tank 81 via the return pipe 812.
Returned to 3. Further, a relief valve 804 is connected to the pipeline 802 via a pipeline 803, and the relief valve 804 regulates the maximum pressure of the hydraulic oil in the pipeline 802 to a predetermined pressure or less.

The cutoff valve 805 and the throttle valve 807 are connected to a direction switching valve 809 via a pipe line 808. The direction switching valve 809 is a three-position switching valve that controls forward / reverse rotation of the hydraulic motor 24 and stop. Direction switching valve 8
09 is connected to an operating rod (not shown) of the cargo handling vehicle,
The operator of the cargo handling vehicle operates the telescopic rails 14 and 16 so as to select the extension or contraction operation. And
The direction switching valve 809 is connected to two ports (not shown) of the hydraulic motor 24 via lines 810 and 811.

Next, the operation of the hydraulic circuit will be described. First, by controlling the opening / closing operation of the shutoff valve 805, the amount of hydraulic oil supplied to the hydraulic motor 24 is selectively controlled between a large flow rate and a small flow rate. That is, the shutoff valve 80
5, the hydraulic oil is supplied to the hydraulic motor 24 at a large flow rate through the cutoff valve 805 and the throttle valve 807, and the cutoff valve 805 is closed to be supplied at a small flow rate only through the throttle valve 807. It As a result, the operating speed of the hydraulic motor 24 is selectively controlled between high speed and low speed. Then, by operating the direction switching valve 809,
A port for supplying hydraulic oil from the hydraulic pump 801 to the hydraulic motor 24 is selected, and the hydraulic motor 24 is rotated in a direction corresponding to the extension or contraction operation of the telescopic rails 14, 16. When the directional control valve 809 is in the neutral position as shown in FIG. 5, the hydraulic oil from the hydraulic pump 801 is supplied to the conduit 81.
Returning to the oil tank 813 via 2, the hydraulic motor 24 stops rotating. It goes without saying that the direction switching valve 809 may be arranged upstream of the shutoff valve 805 and the throttle valve 807.

Next, referring to FIG. 6, a solenoid drive circuit 8 for driving the solenoid 814 of the shutoff valve 805.
2 will be described. In FIG. 2, the proximity switches 68, 7
0 is shown outside the control means 80 to show its arrangement, but is shown in FIG. 6 as a component of the solenoid drive circuit 82 of the control means 80. Further, in FIG. 6, the main circuits of the proximity switches 68 and 70 are simplified and shown by C1 and C2, respectively.

The relay R1 is connected to the load side terminal of the proximity switch 68, and the proximity switch 68 is connected to the dog 74.
When or 78 is detected, the relay R1 is excited and the normally closed contact r1 opens. The relay R2 is connected to the load side terminal of the proximity switch 70, and when the proximity switch 70 detects the dog 72 or 76, the relay R2 is excited and the normally open contact r2 is closed. When the contact r2 is closed, the relay R3 is excited, and after a predetermined time t has elapsed, the timer-type contact r3 described below opens. Here, contact points r2, r
3 are connected to each other in series. Further, as understood from FIG. 6, the relay R4 is connected in series to the contacts r2 and r3. With this configuration, when the contact r2 is closed, the relay R4 is excited until the predetermined time t elapses after the contact r2 is closed. When the relay R4 is excited, the normally closed contact r4 opens. Shut-off valve 80 at contact point r4
5 solenoid 814 is connected.

Next, the operation of the timer-type contact r3 will be described with reference to FIG. The contact r3 is a generally available timer-type contact, and operates according to the time chart shown in FIG. First, the contact r3 is the relay R
It is closed until 3 is excited (state a). And
The relay R3 remains closed (state b) until a predetermined time t elapses when the relay R3 is excited (T = 0). When a predetermined time t elapses (T = t), the contact r3 opens,
The open state continues until the relay R3 is demagnetized (state c). When the relay R3 is demagnetized (T = tr), the contact r3 closes again and returns to the state a.

Next, the operation of the control means 80 is performed in a state where the telescopic rails 14 and 16 are most contracted (however, in this state, the predetermined time t has elapsed after the telescopic rails 14 and 16 have completed the contraction operation. It will be described in order with reference to the relative positions of the proximity switch and the dog, taking as an example the case where the extension is performed from (assuming later). First, telescopic rails 14 and 16
Is in the most contracted state, which is referred to as state A1. In the state A1, the proximity switch 68 detects the dog 78. Therefore, the relay R1 is excited and the contact r
1 is open. On the other hand, the proximity switch 70 is also a dog 7
6, the relay R2 is excited and the contact r2 is closed. Therefore, the relay R3 is excited. However, since the predetermined time t has elapsed, the contact point r3 is open. Therefore, the relay R4 is demagnetized and the contact r4 is closed. Since the contact r1 is open, the solenoid 814 is not excited regardless of whether or not the contact r4 is closed. Therefore, the shutoff valve 805 is closed. That is, while the telescopic rails 14 and 16 are in the most contracted state, the solenoid 814 is demagnetized and the shutoff valve 805 is closed.

Next, when the telescopic rails 14 and 16 start the extension operation from the state A1, the dog 78 is disengaged from the facing position of the proximity switch 68, and the dog 76 is at the facing position of the proximity switch 70, the state A2. Refer to. In the state A2, the proximity switch 68 does not detect the dog 78.
Therefore, the relay R1 is demagnetized and the contact r1 is closed. On the other hand, the proximity switch 70 detects the dog 76. Therefore, the relay R2 is excited and the contact r2 is closed. As a result, the relay R3 is excited, but since the predetermined time t has elapsed, the contact r is the same as in the state A1.
3 is open, relay R4 is demagnetized and contact r4 is closed. Since the contacts r1 and r4 are both closed, the solenoid 814 is excited and the shutoff valve 805 opens. As a result, a large amount of hydraulic oil is supplied to the hydraulic motor 24, the hydraulic motor 24 rotates at high speed, and the telescopic rails 14 and 16 extend at high speed.

Next, reference will be made to the state A3 when the telescopic rails 14 and 16 are further extended so that the dogs 78 and 76 are both separated from the facing positions of the proximity switches 68 and 70. State A
In 3, the proximity switch 68 does not detect the dog 78, so the relay R1 is demagnetized and the contact r1 is closed. Since the proximity switch 70 also does not detect the dog 76, the relay R2 is demagnetized and the contact r2 is open. When the contact r2 opens, the relay R3 is demagnetized and the contact r3 closes. Therefore, in the state A3, the contact r3 is closed but the contact r2 is open, so the relay R4 is demagnetized and the contact r4 is closed. Since the contacts r1 and r4 are closed, the solenoid 814 is excited and the shutoff valve 805
Opens. As a result, a large amount of hydraulic oil is supplied to the hydraulic motor 24, the hydraulic motor 24 rotates at high speed, and the telescopic rails 14 and 16 extend at high speed.

Next, a state A4 is referred to when the telescopic rails 14 and 16 extend to the vicinity of the end of the extension stroke and the proximity switch 70 detects the dog 72. In state A4, the proximity switch 68 has not yet detected the dog 74. In the state A4, the proximity switch 68 moves the dog 7
4, the relay R1 is demagnetized and the contact r1 is closed. On the other hand, since the proximity switch 70 detects the dog 72, the relay R2 is excited and the contact r
2 closes. When the contact r2 is closed, the relay R3 is excited. When a predetermined time t elapses after the relay R3 is excited, the contact r3 opens. Until the contact r3 opens, that is,
The relay R4 is excited and the contact r4 remains open until a predetermined time t elapses after the proximity switch 70 detects the dog 72. During this time, the solenoid 814 is demagnetized and the shutoff valve 805 is closed. As a result, the hydraulic oil supplied to the hydraulic motor 24 decreases, the hydraulic motor 24 rotates at a low speed, and the telescopic rails 14 and 16 extend at a low speed.

It should be noted here that the telescopic rails 14 and 16 must reach the end of the extension stroke when the predetermined time t has elapsed. If the telescopic rails 14 and 16 do not reach the end of the extension stroke, the contact r3 opens with the contact r2 closed, so that the relay R4 is demagnetized and the contact r4 closes. At this time, since the contact r1 is closed, the solenoid 814 is excited and the cutoff valve 805 is opened. Therefore, the hydraulic motor 2
A large amount of hydraulic oil is supplied to 4, hydraulic motor 24 starts to rotate at high speed, and telescopic rails 14 and 16 start to extend at high speed, so that the object of the present invention cannot be achieved.

Next, the end of the extension operation of the telescopic rails 14 and 16 will be referred to as a state A5. In state A5, since the proximity switch 68 detects the dog 74, the relay R1 is excited and the contact r1 opens. Since the proximity switch 70 also detects the dog 72, the relay R2 is excited and the contact r
2 closes. This excites the relay R3, but the contact r3 is opened after the elapse of a predetermined time t. Therefore, the relay R4 is not excited and the contact r4 is closed. Regardless of whether or not the predetermined time t has elapsed, the contact r1 is open, so that in the state A5, the solenoid 814 is not always excited and the cutoff valve 805 is closed. Telescopic rail 1
When 4 and 16 contract from the most extended state, the same operation is performed.

As can be understood from the above description, the proximity switch 68 and the dogs 74, 78 are provided with the telescopic rails 14,
It is provided to protect the solenoid 814 by demagnetizing the solenoid 814 during the cargo handling work in the most extended state or the most contracted state. This allows
The long-term reliability of the shutoff valve 805 is ensured. On the other hand, when the telescopic rails 14 and 16 are expanded and contracted, the solenoid 814 must be excited to operate at high speed. Therefore, the dogs 74, 78 are attached to the telescopic rails 14, 1,
It must be provided so that it immediately comes out of the position facing the proximity switch 68 as soon as 6 starts the extension operation or the contraction operation.

As is clear from the above description, the deceleration operation of the telescopic rails 14 and 16 is started when the proximity switch 70 detects the dog 72 or 76. Therefore, in order to shorten the time when the telescopic rails 14 and 16 operate at low speed, the dogs 72 and 76 are attached to the telescopic rails 14 and 16.
It is desirable to make it as short as possible in the direction of movement. On the other hand, for the purpose of the present invention to reduce the impact generated at the end of the extension or contraction stroke of the telescopic rails 14 and 16, the extension or contraction operation of the telescopic rails 14 and 16 is performed in the vicinity of the end of each stroke. You have to slow down enough. The deceleration acceleration of the telescopic rails 14 and 16 is
It is affected by the mass of the telescopic rails 14 and 16, the capacity of the hydraulic motor 24, the size of the orifice of the throttle valve 807 of the hydraulic circuit 80a, and the like. Therefore, the arrangement and size of the dogs 72 and 76 are determined so as to adjust to these factors and obtain the desired deceleration.

Further, after a predetermined time has elapsed from the time when the proximity switch 70 detected the dog 72 or 76,
The timer-type contact r3 is opened, the relay R4 is demagnetized, and the contact r4 is closed. As a result, the control means 80 causes the dog 7
When 4 and 78 are out of the facing position of the proximity switch 68, the hydraulic motor 24 is rotationally controlled at high speed. That is, the timer-type contact point r3 constitutes a canceling means for canceling the control for reducing the moving speed of the telescopic rails 14 and 16 by the control means 80 in the vicinity of the end of the extension or contraction movement of the telescopic rails 14 and 16. Be understood. Although the above-described embodiment has been described by taking the spreader device for a forklift truck as an example, it goes without saying that the present invention is also applicable to a spreader device for a straddle carrier.

[0034]

As described in detail above, according to the present invention,
When stopping the extension / contraction movement of the extension / contraction rail, the extension / contraction movement speed of the extension / contraction rail can be significantly reduced.
As a result, it is possible to reduce the impact when stopping the extension / contraction movement of the extension / contraction rail.

[Brief description of drawings]

FIG. 1 is a schematic front view of a container spreader device embodying the present invention.

FIG. 2 is a schematic rear view of a container spreader device embodying the present invention.

FIG. 3 is a side view of a forklift equipped with a container spreader device embodying the present invention.

4 is a sectional view taken along the line IV-IV in FIG.
It is a figure which shows the positional relationship of a proximity switch and a dog.

FIG. 5 is a schematic view of a control device for a drive device of a spreader device according to the present invention, mainly showing a hydraulic circuit of the control device.

6 is a schematic diagram of a solenoid drive circuit for driving the solenoid of the shutoff valve of the controller of FIG.

FIG. 7 is a time chart showing the operation of the timer-type contact.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Container spreader device 10 ... Spreader main body 11 ... Rail holder 14 ... Telescopic rail 16 ... Telescopic rail 14d ... Twist lock pin 16d ... Twist lock pin 18 ... Strut 44 ... Telescopic rail drive device 68 ... Proximity switch 70 ... Proximity switch 72 ... dog 74 ... dog 76 ... dog 78 ... dog 80 ... control device for drive device 80a ... hydraulic circuit of control device 82 ... solenoid drive circuit of control device C ... container

Claims (1)

[Claims] 1. A rail holder installed on a spreader body is provided with a pair of left and right telescopic rails having twist lock pins engaging with a fishing hole of a container attached to ends thereof so as to be movable in a lateral direction. A container spreader device in which a holder is provided with a drive device for moving a telescopic rail in a lateral direction, wherein the telescopic rail extends and moves to detect an approach to an end of an extension stroke and outputs a detection signal. In the contraction movement of the telescopic rail, a second detection unit that detects the approach to the end of the contraction stroke and issues a detection signal, and the drive unit based on the detection signal from the first detection unit or the second detection unit. Control device for reducing the extension / contraction movement speed of the extension / contraction rail via the control device, and releasing means for releasing the extension / contraction movement speed reduction control of the extension / contraction rail by the control device. Consisting of further comprising a container spreader apparatus.