JP2000118625A - Cargo transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid interference of a lever and a cargo with each other in the middle of revolving motion of the lever to be engaged witch the cargo to its working position in a load transfer device of a side picking type. SOLUTION: Transmission type optical sensors to detect an obstacle to hinder arrangement of levers 53, 54 at working positions are arranged on both end upper parts of upper forks 35, 36. Light projecting parts S9a, S10a are arranged on the upper fork 35 and light receiving parts S9b, S10b are arranged on the upper fork 36 respectively in a state to face against each other. The light projecting part S9a and the light receiving part 9b are arranged so that projected light passes through a region below a lever 53 and within thickness of the lever 53. The light projecting part S10a and the light receiving part S10b are arranged so that the projected light passes through a region below the lever 54 and within thickness of the lever 54. A control device to control motors 49, 50 controls the motors 49, 50 to revolve the levers 53, 54 to the working positions in a state where no detection signal of the obstacle is output from the light receiving parts S9b, S10b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a load transfer device which is used by being mounted on a stacker crane, an automatic guided vehicle, or the like, and more particularly, to a transfer device which moves back and forth along a side of a load portion. The present invention relates to a load transfer device that transfers a load to a load on a load storage section via a lever that is engaged at a rear end in a transfer direction of the load when the member is moved.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publications Nos. Hei 6-345214 and Hei 7-101508 disclose that a load is horizontally transferred between a load supporting portion such as a shelf configured to place a load on a support plate. A load support table to be loaded, an outgoing / retracting moving member located on the side of the load transfer path between the load supporting table and the load supporting portion, and front and rear pivotally supported at both front and rear ends of the outgoing and moving member. 2. Description of the Related Art There has been proposed a load transfer device having a pair of load pull-in / out arms (lever) (hereinafter, referred to as a side picking type load transfer device).
In this load transfer device, the load pulling-in / out arm is engaged with the rear end in the load transfer direction, and the load is slid on the support plate and the load supporting portion to transfer the load. Conventionally, a sensor for detecting whether or not a load is on a shelf or the like is provided in the load transfer device, but there is no sensor for detecting whether or not the load is placed at a correct position.

[0003]

A side picking type load transfer device is different from a load transfer device of a type in which a load is supported on the upper surface of a fork, and a load is transferred by a lever disposed at an operation position. This is done by pulling or pushing the load in the engaged state. Therefore, when the load is protruded into the range of rotation of the lever when the lever is rotated from the retracted position to the operation position, not only the lever is not disposed in the operation position but also an excessive force is applied to the lever or the load. . As a result, the load may be damaged, or the lever or its drive unit may be damaged.

After the load is transferred to a load support such as a shelf,
When the moving member moves from the advanced position to the standby position, it may come into contact with the load transferred to the predetermined position and a part of the load may protrude from the shelf. If the stacker crane moves in that state, there is a problem that the protruding load interferes with the stacker crane.

The present invention has been made in view of the above problems, and a first object of the present invention is to cause a lever to interfere with a load during the turning operation of the lever engaging with the load to the operating position. An object of the present invention is to provide a load transfer device capable of avoiding the problem. Also,
A second object of the present invention is to provide a load transfer device capable of detecting a transfer failure on a shelf or the like in addition to the above objects.

[0006]

In order to achieve the first object, according to the first aspect of the present invention, there is provided a loading section on which a load is placed, and the loading section provided on the loading section. A guide rail extending along the direction in which the load is transferred to the portion, a retractable moving member movable along the guide rail, and reciprocating the retractable member between a standby position and an advanced position. Retracting drive means for controlling the load on the loading portion provided at both ends in the transfer direction of the retractable moving member at the rear end in the transfer direction when the retractable moving member moves. A load transfer device comprising: a lever rotatably disposed between an operable position and a retractable position that cannot be engaged; and lever driving means for rotating the lever between the operative position and the retracted position. It is difficult to dispose the levers at the working position at both ends of the moving member. A sensor for detecting the become obstacles provided.

According to a second aspect of the present invention, in the first aspect of the present invention, the control device for controlling the lever driving means operates the lever in a state where the sensor does not output an obstacle detection signal. The lever driving means is controlled to rotate to the position.

According to a third aspect of the present invention, in order to attain the second object, in the second aspect of the present invention, the unloading and retreating member moves the retractable moving member from the advanced position to the standby position during the unloading operation. When an obstacle detection signal is output from the sensor in a state where the sensor has moved a predetermined distance or more, the control device determines that a load transfer failure has occurred.

According to the first aspect of the present invention, when the load on the loading portion is transferred to another loading portion, the lever is moved to the operating position by the sensors provided at both ends of the retreating member. The lever is placed in the operative position in a state in which no obstacle to the placement is detected. When the retracting drive means is actuated in that state, the retracting moving member moves along the guide rail, the lever engages the load at the rear end in the transfer direction, and the load moves on the loader. And is transferred onto another mounting portion. After the moving member moves to the predetermined advanced position, the lever is arranged at the retracted position. Next, the retracting drive unit is operated, and the retracting member returns to the standby position. When transferring a load on another loading portion to the loading portion, the retracting drive means is operated in a state where the lever is disposed at the retracted position. Then, after the retreating member moves to the advanced position, the lever is arranged at the operation position in a state in which an obstacle to the arrangement of the lever at the operation position is not detected by the sensor. Next, the retracting drive means is operated to move the retracting member toward the standby position. During this movement, the lever moves while being engaged with the load, and the load is transferred onto the load receiver.

According to the second aspect of the present invention, the first aspect is provided.
Wherein the control device for controlling the lever driving unit controls the lever driving unit to rotate the lever to the operating position in a state where the obstacle detection signal is not input from the sensor. .

According to a third aspect of the present invention, in the second aspect of the present invention, during the unloading operation, the load engages with the load when the moving member moves from the advanced position to the standby position, and the load is removed. When the member is moved to the standby position side so as to cause an obstacle, the sensor outputs an obstacle detection signal even after the moving member moves from the advanced position to the standby position by a predetermined distance or more. The controller determines that a load transfer failure has occurred when the obstacle detection signal is input from the sensor.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment in which the present invention is embodied in a load transfer device mounted on a stacker crane of an automatic warehouse will be described below with reference to FIGS.

As shown in FIG. 2, the automatic warehouse 1 includes a pair of left and right frame shelves 2a and 2b arranged to face each other. In the frame shelves 2a and 2b, a large number of storage sections 3 are provided at predetermined intervals in a continuous direction (left and right direction in FIG. 2) and a step direction (a direction perpendicular to the paper surface). Each storage unit 3 is a column 4
And a shelf plate 5 disposed therebetween. The shelf plate 5 is formed to have a length that allows a plurality of loads W to be placed thereon. An entrance 6 and an exit 7 are provided at one end (left end in FIG. 2) of the frame shelves 2a and 2b. A belt conveyor is used as the entrance 6.

A passage 8 between the frame shelves 2a and 2b of the automatic warehouse 1
, A rail 9 is laid, and a stacker crane 10 is provided on the rail 9 so as to be able to run. The stacker crane 10 includes a pair of masts 1 erected on a traveling platform 11.
The carriage 13 is suspended between the two so as to be able to move up and down, and a fork device 14 is provided on the carriage 13 as a load transfer device capable of moving back and forth in the left-right direction (vertical direction in FIG. 2).
A traveling motor 15 for traveling the stacker crane 10 and an elevating motor 16 for elevating the carriage 13 are arranged on the traveling platform 11. A crane controller 17 for controlling the driving of both motors 15 and 16 is provided on the lower front surface of the front mast 12. Then, the stacker crane 10 stops at a position corresponding to the end of the entrance 6 (belt conveyor), and transfers the load W onto the fork device 14 from the end of the stopped belt conveyor.

Next, the fork device 14 will be described. FIG. 1 is a partially cutaway schematic view of the fork device 14 as viewed from the frame shelf 2b side, and FIG. 4 is a partially omitted side view as viewed from the left side of FIG.
FIG. 5 is a schematic sectional view taken along line VV of FIG. FIG.
The fork device 14 is fixed on the carriage 13 at the base portion 18 as shown in FIG. The base portion 18 includes a pair of support members 19 arranged in a state orthogonal to the load transfer direction (vertical direction in FIG. 5), and a load portion 20 fixed to both support members 19. . At both ends of the loading section 20, sensors S1 and S2 for detecting a load on the storage section 3, the entrance 6 or the exit 7 are attached. Both ends of the loading section 20 are formed so as to be inclined downward toward the end.

As shown in FIG. 5, lower forks 21 and 2 as a pair of left and right guide rails are provided between the two support members 19.
2 is fixed in a state orthogonal to the support member 19, that is, in a state extending along the load transfer direction. Both lower forks 21, 22 are formed of a plate material. Both lower forks 2
Support plates 23 and 24 are fixed to the inside of the first and second 22 via a spacer 25. Both lower forks 21 and 2
A rotation shaft 26 that penetrates the support plates 23 and 24 is rotatably supported between substantially the center portions of the two.

A motor M for fork retraction is fixed inside the support plate 23, and a drive gear 28
(Shown in FIGS. 1 and 4) are fixed so as to be integrally rotatable.
Between the lower fork 21 and the support plate 23, a gear train 30 including a pinion 29 fixed to the rotation shaft 26 so as to be integrally rotatable is provided. Between the lower fork 22 and the support plate 24, a gear train 32 including a pinion 31 fixed to the rotating shaft 26 so as to be integrally rotatable is provided.
It is arranged symmetrically. The pinions 29 and 31 are rotated in the same direction by driving the motor M.

As shown in FIGS. 1 and 3, inside the lower forks 21 and 22, middle forks 33 and 34 which constitute a moving member are reciprocated with respect to the lower forks 21 and 22 in the load transfer direction. It is movably supported. Inside the middle forks 33, 34, upper forks 35, 36 constituting the retreating member are provided.
Are supported so as to be able to reciprocate in the load transfer direction.
The lower forks 21 and 22, the middle forks 33 and 34, and the upper forks 35 and 36 are formed symmetrically with respect to a vertical plane passing through the center of the loading section 20 and parallel to the load transfer direction. Hereinafter, since the left and right sides have the same configuration, the configuration on the left side will be described.

As shown in FIG. 3, the middle fork 33 is constituted by a support rail formed in a crank shape, and the lower fork 2
1 is supported so as to be relatively movable. Upper fork 3
Reference numeral 5 denotes a lower part of the middle fork 33 which is supported by the middle fork 33 via a linear joint 38 so as to be relatively movable. Rolling guides (ball sliders) are used as the linear motion joints 37 and 38. In this embodiment, a slide rail unit in which a support rail and a rail-shaped ball slider as a linear motion joint are unitized is used, and the support rail is used as a middle fork 33.

As shown in FIGS. 1 and 3, the lower fork 21 is connected to a linear motion joint 37 via a block 39 fixed to the upper end thereof. Upper fork 35
Is formed in a substantially inverted L-shaped cross section, and is connected to a linear motion joint 38 via a block 40 in a state where the hanging piece is located above the support plate 23. Middle fork 33
A rack 41 that meshes with the pinion 29 extends along a middle fork 33 via a bracket 42 at a lower portion of the rack.

As shown in FIG. 4, sprockets 43 and 44 are rotatably supported at upper ends of the middle fork 33 so as to be positioned in a vertical plane parallel to the middle fork 33. The sprocket 43 is located at the left end of the middle fork 33, that is, the lower fork 2 in FIG.
The sprocket 44 is provided at a position corresponding to the left end of the first fork 1, and at a position corresponding to the right end of the lower fork 21 in FIG. Sprockets 43 and 44 are linear motion joints 3.
7 is rotatably supported by a support shaft (not shown) screwed to it.

As shown in FIG. 4, a support piece 45 is fixed to one block 39 fixed to the center of the lower fork 21 and to the left in the center of FIG. 4, and the support piece 45 is wound around a sprocket 44. One end of the chain 46 is connected. A support piece 47 is fixed to the other block 39 fixed to the center right of the lower fork 21, and one end of a chain 48 wound around the sprocket 43 is connected to the support piece 47.

One of the blocks 40 fixed to the left end of the upper fork 35 in FIG.
(Shown in FIG. 3) is fixed, and the other end of the chain 46 wound around the sprocket 44 is connected to the bracket 40a. The other block 40 fixed to the right end of the upper fork 35 in FIG.
b (shown in FIG. 3) is fixed, and the other end of the chain 48 wound around the sprocket 43 is connected to the bracket 40b.

The motor M, drive gear 28, pinion 29,
31, gear trains 30, 32, rack 41, sprocket 4
The retracting drive means for reciprocating the retractable member between the standby position and the advanced position is constituted by the chains 3, 44 and the chains 46, 48. The sprocket 43 moves the upper forks 35, 36 to the left in FIG. 4 via the chain 48 when the middle forks 33, 34 move to the left in FIG. Sprocket 44 is middle fork 3
When the members 3 and 34 move rightward in FIG. 4, the upper forks 35 and 36 are moved rightward in FIG.

As shown in FIGS. 1 and 4, above the upper fork 35, a motor 49 as lever driving means is provided.
A pair of 50 is provided so as to extend along the longitudinal direction of the upper fork 35. The motors 49 and 50 are supported on the upper fork 35 via a support bracket 51 with their base ends facing each other. Motor 4
Lever 53 and 54 are supported at the tip of 9 and 50 rotation part 52 so that rotation is possible integrally. The levers 53 and 54 are operative positions at which the upper fork 35 can be engaged with the load W on the loader 20 at the rear end in the transfer direction when the upper fork 35 is moved.
It is pivotally disposed to the retractable position where it cannot be engaged. In this embodiment, the position where the levers 53 and 54 extend vertically upward as shown by the solid line in FIG. 3 is the retracted position, and obliquely downward toward the loading portion 20 side as shown by the chain line in FIG. The position extending to the position becomes the operation position. The levers 53 and 54 are formed such that their centers in the width direction are biased toward the inside of the fork device 14 with respect to the centers of the motors 49 and 50 when they are arranged at the retracted position.

The rotating portion 52 is formed in a cylindrical shape, and has a fan-shaped detected portion 55 projecting from the peripheral surface substantially at the center in the longitudinal direction so as to extend along the circumferential direction. As shown in FIGS. 1 and 4, the detected portion 55 is provided on the upper fork 35.
Sensors S3 to S6 are provided at positions corresponding to the brackets 56,
57 (only shown in FIG. 4).
Proximity sensors are used for the sensors S3 to S6. The sensors S3 and S5 disposed on the lower side detect the detection target 55 in a state where the levers 53 and 54 are disposed at the retracted positions, and the sensors S4 and S6 disposed on the upper side are operated by the levers 53 and 54. It is disposed at a position for detecting the detection target 55 in the state where it is disposed at the position.

Sensors S7 and S8 (shown only in FIG. 4) for confirming that the upper fork 35 does not interfere with an obstacle when the upper fork 35 moves to the advanced position are provided at lower ends of both ends of the upper fork 35. Fixed. A beam sensor is used for the sensors S7 and S8, and outputs a detection signal when there is an obstacle nearer than a predetermined distance. When the detection signal is output, the driving of the motor M is stopped. .

At both ends of the upper forks 35, 36, sensors for detecting obstacles which are obstacles for disposing the levers 53, 54 at the operation positions are provided. In this embodiment, a transmission type optical sensor is used as a sensor,
The light projecting portions S9a and S10a are arranged on the upper fork 35, and the light receiving portions S9b and S10b are arranged on the upper fork 36 so as to face each other. The light projecting portion S9a and the light receiving portion 9b are arranged such that the light passes below the lever 53 through windows formed in the upper forks 35 and 36 and a range within the thickness of the lever 53. Emitter S10
a and the light receiving portion 10b are provided with windows and levers 54 formed in the upper forks 35 and 36 below which the light is projected.
Are arranged so as to pass through a range within the thickness of. In addition, the light emitting parts S9a and S10a are arranged on the upper fork 36 side,
The light receiving sections S9b and S10b may be provided on the upper fork 35 side.

Control device C for controlling motors 49 and 50
(Only shown in FIG. 5) is mounted on the carriage 13. The control device C includes light-emitting units 9a and 10a and light-receiving units 9b,
10b is electrically connected. The control device C controls the motors 49 and 50 so as to rotate the levers 53 and 54 to the operation position in a state where no obstacle detection signal is output from the light receiving units 9b and 10b. During the unloading operation, the control device C sets the light receiving sections 9b and 10b in a state where the upper forks 35 and 36 have moved from the advanced position to the standby position side by a predetermined distance or more (in this embodiment, returned to the standby position).
When the obstacle detection signal is output from, it is determined that the transfer failure of the load W has occurred. And crane controller 1
7 to output an abnormal signal. Note that the control device C is a sensor S
1 to S8, and controls the motor M based on output signals of the sensors S1 to S8.

Next, the operation of the apparatus configured as described above will be described by taking as an example a case where a load W is stored in the storage section 3 of the right frame shelf 2b from the storage opening 6. Stacker crane 1
In the case of 0, the traveling motor 15 is driven by a command from the crane controller 17, travels along the rail 9, and then stops at a position corresponding to the entrance 6. The lifting motor 16 is driven by a command from the crane controller 17, and the carriage 13 stops at a position corresponding to the entrance 6. The carriage 13 stops at a position where the upper surface of the loading section 20 is at the same height as the upper surface of the entrance 6 (belt conveyor).

The crane controller 17 confirms from the output signal from a sensor (not shown) that there is no load W on the loading section 20 and that the load W exists at the entrance 6 based on the output signal from the sensor S2. Then, the motor M is driven. By driving the motor M, each of the pinions 29 and 31 is rotated in the same direction, and both the middle forks 33 and 34 are moved together with the rack 41 to the right in FIG.

When the sprocket 44 moves together with the middle forks 33 and 34, one end of a chain 46 wound around the sprocket 44
2, the sprocket 44 moves while rotating counterclockwise in FIG. As a result, the upper forks 35, 36 supported by the middle forks 33, 34 via the linear joint 38 and connected to the other end of the chain 46 move the middle forks 33, 34 in the moving direction of the sprocket 44. Move twice.

When the upper forks 35, 36 reach the advanced position, the driving of the motor M is stopped, and the upper forks 35, 36 stop at the predetermined advanced position. In addition,
If there is an obstacle at a position that interferes with the upper forks 35, 36, the upper forks 35, 36 and the middle fork 3
A detection signal is output from the sensor S8 during the movement of the upper and lower forks 35 and 34.
36 is stopped during the movement.

After the upper forks 35, 36 have stopped at the predetermined advance positions, the control device C confirms that no obstacle detection signal has been output from the light receiving sections 9b, 10b,
A drive command is output to both motors 49 and 50. Then, the motors 49 and 50 are driven, and the levers 53 and 54 are arranged at the operation positions. Motors 49 and 50 are sensors S4 and S6
Is stopped when an ON signal is output from the controller.
Next, the motor M is driven to rotate in the opposite direction to the above, and each pinion 29, 31 is rotated in the counterclockwise direction in FIG.
Then, the middle forks 33, 34 are moved to the left in FIG.
Moves twice the moving distance of the middle forks 33, 34 in the same direction.

Since the levers 53 and 54 are located at the operation positions, the lever 54 engages with the rear end of the load W in the transfer direction during the movement of the upper forks 35 and 36, and the upper forks 35 and 36 are moved. Accordingly, the load W is moved toward the loading section 20. When the upper forks 35, 36 and the middle forks 33, 34 reach the standby position and the detection signal is output from a sensor (not shown), the driving of the motor M is stopped, and the upper forks 35, 36 and the middle forks 33, 34 Stop at the standby position. Thus, the transfer operation of the load W from the entrance 6 to the loader 20 is completed.

Next, the traveling motor 15 and the elevating motor 16 are driven, and the stacker crane 10 travels to a position corresponding to the storage section 3 in which the load W is to be stored, and as shown in FIG. It stops at the position corresponding to the storage unit 3. And the crane controller 17 detects the sensor S2
After confirming that there is no load W in the storage unit 3 based on the output signal of the above, the transfer operation of the load W to the storage unit 3 is started. First, the motor M is driven to move the upper forks 35 and 36 and the middle forks 33 and 34 to the predetermined advance positions in the same manner as described above. Since the levers 53 and 54 remain in the operation position, the lever 53 engages with the rear end in the transfer direction of the load W during the movement of the upper forks 35 and 36, and the load is moved with the movement of the upper forks 35 and 36. W is storage unit 3
Moved toward. Then, as shown in FIG. 6B, after the upper forks 35, 36 have moved to the advanced position, the motors 49, 50 are driven and the sensor S
3, when the ON signal is output from S5, the operation is stopped, and as shown in FIG. 6C, the levers 53 and 54 are in the retracted position. Next, the motor M is driven to return the middle forks 33 and 34 and the upper forks 35 and 36 to the standby position. Then, one cycle of the operation of transferring the load W from the load storage unit 20 to the shelf 5 of the storage unit 3 is completed.

While the upper forks 35 and 36 are moving from the advanced position to the standby position, the upper forks 35 and 36 come into contact with the load W for some reason, and as shown in FIG. There is a case where it moves to the side and its end protrudes from the storage unit 3. When the upper forks 35 and 36 return to the standby positions, the control device C
It is determined whether an obstacle detection signal is output from b and 10b, and if it is output, it is determined that a transfer failure of the load W has occurred. Therefore, as shown in FIG.
When the protruding transfer failure occurs, the control device C surely recognizes it. Then, the control device C outputs an abnormal signal to the crane controller 17. When the crane controller 17 inputs an abnormal signal, the stacker crane 10
Is not started, and the running is started after the abnormality is resolved.

The same operation is performed when taking out the load W from the storage section 3 of the right frame shelf 2b and storing the load W in the other storage section 3 on the right side. On the other hand, the load W is placed on the left frame shelf 2a.
When storing the goods W and when unloading the load W from the outlet 7,
Middle forks 33, 34 and upper forks 35, 3
When 6 moves to the advanced position, it is moved toward the left side of FIG. Therefore, when the crane controller 17
Is rotated in the opposite direction to that described above, and the same control is performed in the other cases.

This embodiment has the following effects. (1) Lever 5 on both ends of upper forks 35 and 36
Sensors for detecting obstacles that hinder the placement of the light receiving sections S9a and S10a and the light receiving section S9
b, S10b). Therefore, it is possible to prevent the levers 53, 54 from interfering with the load W during the turning operation of the levers 53, 54 engaging with the load W to the operation position, and the load W may be damaged or the levers 53, 54 or the motor 49, 50 can be prevented from being damaged.

(2) The control device C includes the light receiving units S9b and S9b.
The lever driving means (motors 49, 50) is controlled so as to rotate the levers 53, 54 to the operating position in a state where no obstacle detection signal is input from 10b. Therefore, the levers 53 and 54 are rotated to the operation position only in a state where they do not interfere with the obstacle, and there is no possibility that the levers 53 and 54 will interfere with the load W during the rotation.

(3) The control device C is used for unloading work.
When an obstacle detection signal is input from the light receiving units S9b and S10b in a state where the upper forks 35 and 36 have moved from the advanced position to the standby position, it is determined that a transfer failure of the load W has occurred. Then, an abnormal signal is output to the crane controller 17. Therefore, the crane controller 17 can start running the stacker crane 10 after the abnormality is resolved, and can avoid the stacker crane 10 from interfering with the load W during running.

(4) The light projecting sections S9a and 10a and the light receiving sections 9b and 10b are arranged so that the light passes below the levers 53 and 54 and passes through a range within the thickness of the levers 53 and 54. Therefore, the load W in a state shifted from the normal position without erroneously detecting the load W in the normal position is detected by the lever 5.
3, 54 can be detected.

(5) Since a transmission type optical sensor is used as a sensor for detecting an obstacle, erroneous detection is reduced as compared with a reflection type optical sensor. (6) The levers 53 and 54 are connected to the upper forks 35 and 3
6 is directly rotated by the motors 49 and 50 disposed so as to extend along its longitudinal direction, so that the mechanism for rotating and disposing the levers 53 and 54 between the retracted position and the operating position is simplified. . Accordingly, the number of parts of the rotating mechanism of the levers 53 and 54 is reduced, so that the number of assembling steps is reduced, the space required for disposing the rotating mechanism can be reduced, and the dead space in the storage section 3 can be reduced. . Further, the weight is reduced, and the power consumption of the motor M and the like can be reduced.

(7) The middle forks 33 and 34 and the upper forks 35 and 36 are provided as a pair on the left and right, and the upper forks 35 and 36 are moved in an interlocked state.
The load W is moved while being engaged with the pair of left and right levers 53 and 54. Therefore, the load W can be reliably transferred even if the lengths of the levers 53 and 54 are shorter than the configuration in which the lever is provided on one side.

The embodiment is not limited to the above, and may be embodied as follows, for example. ○ A reflection type optical sensor is used instead of a transmission type optical sensor as an obstacle detection sensor. The sensor receives the reflected light from the obstacle when there is an obstacle, and the optical sensor does not receive the reflected light when there is no obstacle, so that the presence or absence of the obstacle can be detected. The optical sensor may be provided on both upper forks 35 and 36, or may be provided on only one of them. However, the detection error is reduced when both are provided.

When a transmissive optical sensor is used as a sensor for detecting an obstacle, a light projecting unit and a light receiving unit are arranged on one of the upper forks 35 and 36 at predetermined intervals above and below the other. May be provided with a reflecting member. In this configuration, when the light is projected and reflected by the obstacle, the light receiving unit cannot receive the light, and the light receiving unit receives only the reflected light from the reflecting member.

At the time of unloading work, it is determined whether or not a transfer failure of the load W has occurred. Before the upper forks 35, 36 return to the standby position, the upper forks 35, 36 are moved from the advanced position to the standby position. It may be performed in a state where it has moved a predetermined distance or more to the side. For example, when the position of the obstacle detection sensor reaches the end of the storage section 3, it may be determined whether or not an obstacle detection signal is output from the sensor. In addition,
In this case, a means for detecting that the obstacle detection sensor has reached a predetermined position is required. According to this configuration, it is possible to detect that a load transfer failure has occurred even if the amount of displacement of the load W cannot be detected when the upper forks 35 and 36 have returned to the standby positions.

As the lever driving means, a motor having a general rod-shaped driving shaft is used, or a rotary solenoid or the like is used. Also in these cases, levers 53 and 5
4 is directly rotated by the rotation actuator,
The structure becomes simple.

The upper forks 35, 3 are configured to rotate the levers 53, 54 between the operating position and the retracted position.
Instead of using an actuator such as a motor provided on the motor 6, a configuration disclosed in, for example, JP-A-6-345214 or JP-A-7-101508 may be adopted.

The moving member, that is, the middle fork 3
3, 34 or the upper forks 35, 36 may be provided, that is, a configuration in which the retractable member is provided on only one side of the fork device 14. In this case, the load W is transferred even if the lever is on only one side by lengthening the lever.

In place of the configuration in which the lever located on the rear side in the transfer direction of the load W and the lever located on the front side are simultaneously rotated, only the lever located on the rear side in the transfer direction of the load W is replaced. It is configured to rotate to the operating position. In this case, compared to a configuration in which all levers are driven at the same time, the levers 53, 53
The power consumption for driving 54 is reduced.

The operation positions of the levers 53 and 54 are not limited to the positions extending obliquely downward toward the loading section 20, but may be the horizontal positions or the positions extending obliquely upward. ○ Lower forks 21 and 22, middle forks 33 and 3
4 and a structure in which the distance between the upper forks 35 and 36 can be changed, that is, the lower forks 21 and 22 are disposed so as to be movable in a direction orthogonal to the support member 19, and are supported by a driving mechanism such as a ball screw mechanism or a chain. The position on the member 19 can be changed.

The structure for supporting the middle forks 33 and 34 and the upper forks 35 and 36 movably along the longitudinal direction with respect to the lower forks 21 and 22 and the driving mechanism thereof may be appropriately changed. For example, the mechanism for driving the upper forks 35, 36 so that the amount of movement of the middle forks 33, 34 is greater than the amount of movement of the middle forks 33, 34 may be a combination of a rack and a pinion instead of a combination of a chain and a sprocket.

Instead of the belt conveyor, a loading table for loading the load of a self-propelled trolley equipped with a forklift or a load transfer device may be used as the entrance 6. The present invention may be applied to a type of stacker crane in which a plurality of (for example, two) fork devices 14 are provided on the carriage 13.

Instead of mounting the fork device 14 on the stacker crane 10, the fork device 14 may be mounted on a self-propelled bogie that runs on a passage other than the passage of the automatic warehouse. For example, a self-propelled trolley that carries the load W into the entrance 6 or a load W from the exit 7
Equipped on a self-propelled trolley that carries

The inventions (technical ideas) other than those described in the claims which can be grasped from the embodiment will be described below together with their effects. (1) In the invention according to any one of claims 1 to 3, the guide rail and the retreating member are provided as a pair of left and right members, and the retraction driving means includes a pair of left and right member members. Drive in conjunction. In this case, the load is moved while being engaged with the pair of left and right levers, so that the load can be reliably transferred even if the length of the lever is short as compared with a configuration in which the lever is provided on one side.

(2) A stacker crane comprising the load transfer device according to claim 3 on a vertically movable carriage. In this case, even if a load transfer failure occurs during the unloading operation, the traveling of the stacker crane can be started after the abnormality is resolved, and it is possible to prevent the stacker crane from interfering with the load during traveling.

[0058]

As described in detail above, claims 1 to 3 are described.
According to the invention described in (1), it is possible to avoid the lever from interfering with the load during the turning operation of the lever engaging with the load to the operation position, and it is possible to prevent the load from being damaged or the lever or the lever driving means from being damaged. Can be prevented.

According to the second aspect of the present invention, the lever is rotated to the operating position only in a state where the lever does not interfere with the obstacle, and there is no possibility that the lever will interfere with the load during the rotation. According to the third aspect of the present invention, it is possible to detect a defective transfer of a load to a shelf or the like during the unloading operation.

[Brief description of the drawings]

FIG. 1 is a partially cutaway schematic front view of a fork device according to an embodiment.

FIG. 2 is a schematic plan view of an automatic warehouse.

FIG. 3 is a partially enlarged view of FIG. 1;

FIG. 4 is a schematic side view of a fork device.

FIG. 5 is a partially omitted cross-sectional view taken along line VV of FIG. 1;

FIG. 6 is a schematic plan view showing the unloading action of the fork device.

[Explanation of symbols]

14: Fork device as a load transfer device, 20: Loading portion, 21, 22: Lower fork as a guide rail,
29, 31... A pinion that constitutes the drive means;
34... Middle fork as an outgoing and moving member, 35, 3
Reference numeral 6 denotes an upper fork, reference numeral 41 denotes a rack that constitutes a drive unit, and reference numerals 43 and 44 refer to sprockets.
48: chain, 49, 50: motor as lever driving means, 53, 54: lever, C: control device, S
9a, 10a: a light projecting portion constituting a sensor for detecting an obstacle; S9b, S10b: a light receiving portion; M: a motor constituting a driving means;

Claims (3)

[Claims] 1. A loading section on which a load is placed, a guide rail provided on the loading section and extending along a direction in which the load is transferred to the loading section, and a guide rail extending along the guide rail. Moving members movable in and out, moving means for reciprocating the moving members between a standby position and a moving position, and both ends in the transfer direction of the moving members. A lever rotatably arranged between a working position engageable at a rear end in a transfer direction of the load on the load storage portion and a retractable position not engageable with the load on the load storage portion when the moving member is moved; Claims 1. A load transfer device comprising a lever driving means for rotating a lever between the operating position and the retracted position, wherein it is an obstacle to disposing the lever at the operating position at both ends of the retractable moving member. A load transfer device equipped with a sensor that detects obstacles. 2. A control device for controlling the lever driving unit controls the lever driving unit to rotate the lever to an operation position in a state where the sensor does not output an obstacle detection signal. 2. The load transfer device according to 1. 3. The control device according to claim 1, wherein, when an unloading operation is performed, when an obstacle detection signal is output from the sensor in a state where the retractable moving member has moved from the advanced position to the standby position by a predetermined distance or more, the control device transfers the load. 3. The load transfer device according to claim 2, wherein it is determined that a loading defect has occurred.