JPH11278606A - Automated storage and retrieval system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To always hold a lift rail in a horizontal attitude by placing articles on a mobile body moving along the lift rail, driving a pair of hanging members and detecting the inclination of the lift rail in the height direction. SOLUTION: A lift rail 5 is provided with a mobile body 8 moving along the interior of the lift rail 5 in parallel. A control device controls the vertical motion of the lift rail 5, running of the mobile body 8 and placing of articles 41 by a robot hand 9. Generally, hanging members 6a and 6b are made to move at the same speed and moves the lift rail 5 in the vertical direction while holding the lift rail 5 horizontal by controlling servo motors 7a and 7b in synchronism with each other. Either the servo motor 7a or 7b is driven to minimize the difference between the elongation caused in the hanging member 6a or 6b based on the detection signals sent to the control device from sensors 13 and 14. For this reason, the inclination of the lift rail 5 in the height direction is corrected, making it possible to hold the lift rail 5 in a horizontal attitude.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic warehouse in which a pair of opposing racks are arranged in parallel at intervals.

[0002]

2. Description of the Related Art Conventionally, as an automatic warehouse, a pair of opposing racks are arranged in parallel at an interval, and a vertical drive unit provided near both ends of one rack supports a vertical rail to raise and lower the rack. In addition, there is known a vehicle which is configured as described above and is provided with a traveling body which travels along the elevating rail to transfer the racks and articles.

[0003]

The lifting rail is lifted and lowered by a hanging member such as a belt or a chain attached to both ends. However, each of the hanging members extends due to long-term use and the like, and each of the lifting members is lifted. If the elongation is different, there is a possibility that the elevating rail tilts left and right (in the height direction), and the vertical and horizontal stop positions of the traveling body on which the articles are transferred are shifted, so that the workpiece transfer position becomes inaccurate. .

[0004] The present invention has been made by focusing on such problems existing in the prior art. The challenge is
An object of the present invention is to provide an automatic warehouse capable of controlling a driving amount of each suspension member so as to cancel a difference in extension of a suspension member to be moved up and down by a lift rail, and keeping a horizontal posture of the lift rail.

[0005]

In order to achieve the above object, according to the present invention, a pair of masts provided on one rack side, an elevating rail moving along the mast, A traveling body for moving along the rails to transfer articles, a pair of hanging members for raising and lowering the lifting rail, a pair of lifting driving means for driving each of the lifting members, And a tilt detecting means for detecting a tilt in the height direction.

According to a second aspect of the present invention, in the first aspect of the present invention, the elevation driving means is separately controlled based on a detection result of the inclination detecting means. According to a third aspect of the present invention, in the second aspect of the invention, the inclination detecting means includes a pair of detected members provided at both ends of the elevating rail, and a pair of masts for detecting the detected members. And a pair of sensors provided at the same height position.

Therefore, according to the first aspect of the present invention, even if the elevating rail is inclined in the height direction due to the difference in extension of the pair of hanging members for elevating the elevating rail, the inclination is detected by the inclination detecting means. The inclination of the lift rail can be corrected by separately controlling the lift drive means.

According to the second aspect of the present invention, in addition to the operation of the first aspect of the present invention, the elevation attitude of the elevation rail is controlled by separately controlling the elevation drive means based on the detection result of the inclination detection means. Can be kept. According to the third aspect of the present invention, in addition to the operation of the second aspect, each of the up-and-down drives is controlled so that the sensors provided at the same height position of each mast simultaneously detect the member to be detected. By controlling the means, the horizontal posture of the lifting rail can be easily maintained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An automatic warehouse according to the present embodiment will be described with reference to the drawings. The automatic warehouse 1 according to the present embodiment includes a rack 2 that is arranged in parallel to face each other, and a crane 3 that transfers an article 41 to the rack 2. The crane 3 is provided with a pair of masts 4 provided near both ends on one side of the rack 2, a lift rail 5 that moves up and down along the mast 4, and moves horizontally along the lift rail 5. Traveling body 8, a timing belt provided on the mast 4, a timing belt for suspending the elevating rail 5, suspension members 6 a and 6 b such as a wire and a chain, and a servo motor (elevation drive) for driving the suspension members 6 a and 6 b, respectively. Part) 7a, 7b
And inclination detecting means 15 for detecting the inclination of the lifting rail 5 in the height direction.

The lift rail 5 is supported by lift tables 31a and 31b. The lifting members 31a and 31b have a hanging member 6 attached thereto.
a and 6b are attached, and the suspension members 6a and 6b are taken up by the servomotors 7a and 7b via the take-up drum 32, so that the lift tables 31a and 31b are moved up and down. Reference numeral 33 denotes a guide roller provided on the elevating tables 31a and 31b. Numeral 34 is a counterweight connected to the lifts 31a and 31b by a belt 35 so as to move up and down inside the mast 4.

The elevating rail 5 has a traveling body 8 that moves in parallel along the inside thereof by a driving source (not shown). The traveling body 8 includes a turntable 20 and a robot hand 9. The robot hand 9 is arranged on a turntable 20 and the turntable 20
By turning by 0 degrees, the racks 2 can be expanded and contracted with respect to the racks 2 on both sides of the elevating rail 5 so that the articles 41 can be transferred. The robot hand 9 includes a first arm 21 that swings with respect to the turntable 20, a second arm 22 that swings in a direction opposite to the first arm 21, and a second arm 22 that swings around the swing arm. And a hand member 23 for supporting the supported article 41. First
When the first arm 21 swings, the second arm 22 swings in the opposite direction, so that the swing shaft for supporting the hand linearly moves back and forth by the swing of the first arm 21 to smoothly move the article. 41 can be transferred. Since the swing shaft supporting the hand member 23 is swingable with respect to the second arm 22,
Even if the second arm 22 swings, the direction of the hand member 23 is constant, and there is no possibility that the hand member 23 collides with the rack 2 or the like. The expansion and contraction of the robot hand 9 is controlled by the arms 21 and
The driving is performed by a drive transmission member (not shown) built in each of the motors 2 and 23.

At both ends of the lift rail 5, docks 11 and 12 are provided, respectively, and U-shaped sensors 13 and 14 for detecting the docks 11 and 12 are provided with masts 4 and 4, respectively. Are provided at the same height near the lower side. With the docks 11 and 12 and the sensors 13 and 14,
The tilt detecting means 15 in the height direction of the lifting rail 5 is constituted. When the sensors 13 and 14 detect the docks 11 and 12, respectively, they send detection signals to the control device 10.

The control device 10 controls the lifting and lowering of the lifting rail 5, the traveling of the traveling body 8, the transfer of the article 41 by the robot hand 9, and the like, and usually synchronizes the driving of the servo motors 7a and 7b. By controlling, the suspension member 6
a and 6b are moved at the same speed, and are lifted and lowered while keeping the posture of the lift rail 5 horizontal. Further, based on the detection signals from the sensors 13 and 14 sent to the control device 10, the servo motor 7a or 7b is controlled so as to eliminate the difference in elongation occurring in the suspension member 6a or 6b.
Is controlled so that only one of them is driven, the inclination in the height direction of the elevating rail 5 is corrected, and the horizontal posture can be maintained.

The following describes the correction in the case where the lifting rail 5 is extended, for example, when the suspension member 6a is extended compared to the suspension member 6b, and the dock 11 side is inclined downward. The inclined lifting rail 5 is lowered by the control device 10 to a height position for inclination correction. From there, the controller 10 drives the servo motors 7a, 7b slowly until the one of the sensors 13, 14 detects one of the dogs 11, 12, so that the lifting rail 5 is slowly lowered. When the dock 13 is detected by the sensor 13, a detection signal is sent from the sensor 13 to the control device 10, and the control device 10 stops driving the servomotor 7 a on the dog 11 side. On the other hand, the driving of the servo motor 7b is continued. When the dock 12 is detected by the sensor 14, a detection signal is sent from the sensor 14 to the control device 10, and the control device 10 stops driving the servo motor 7b on the dog 12 side. As a result, the state in which both docks 11 and 12 are detected by the sensors 13 and 14, that is, the elevation rail 5 is in a horizontal state. Then, the reference value (zero point) provided in the control device 10 is reset, and thereafter, the motor 7 is reset.
When a and 7b are controlled synchronously, the lift rail 5 moves up and down while being kept horizontal.

The present invention may be embodied as follows. In the automatic warehouse 1 according to the present embodiment, the sensors 13 and 14 are provided below the mast in order to correct the inclination of the lift rail 5. It may be within the range in which it can be raised and lowered. For example, it may be provided at a position corresponding to the home position where the lifting rail 5 stops frequently, and the inclination may be corrected each time the lifting rail 5 stops at the home position.

In addition to the method of correcting the inclination, in addition to controlling the drive so that the docks are simultaneously detected by both sensors as in the present embodiment, one dock is detected and then the other dock is detected. Alternatively, the inclination may be corrected by controlling the drive amount of each servo motor thereafter based on the time difference until the movement and the difference in the moving distance.

In this embodiment, the docks 11 and 12
Is provided so as to protrude from the side end portion of the lifting rail 5, but it may be provided on the back surface (rail supporting member 31) side of the lifting rail 5, and the sensors 13 and 14 may be provided correspondingly. .

[0018]

Since the present invention is configured as described above, it has the following effects.

According to the first aspect of the present invention, even if the elevating rail is inclined in the height direction due to the difference in extension of the pair of suspension members, the inclination can be detected by the inclination detecting means. By separately controlling the lifting / lowering driving means, it is possible to correct the inclination of the lifting / lowering rail in the height direction, and it is possible to provide an automatic warehouse that can always maintain the horizontal posture of the lifting / lowering rail. Since the horizontal position of the lifting rail is maintained, articles can be accurately transferred to any rack.

According to the invention described in claim 2, according to claim 1,
In addition to the effect of the invention described in the above, by separately controlling the lifting and lowering driving means based on the detection result of the inclination detecting means,
The horizontal position of the lifting rail can be maintained.

According to the invention described in claim 3, according to claim 2,
In addition to the effects of the invention described in (1), the horizontal position of the lift rail can be easily controlled by controlling each lift drive means so that sensors provided at the same height position of each mast simultaneously detect the detected member. Can be kept.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of an automatic warehouse according to an embodiment.

FIG. 2 is a front view of a main part of the automatic warehouse according to the present embodiment.

FIG. 3 is an explanatory diagram showing correction of a tilt in a height direction of a lifting rail.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Automatic warehouse 2 Rack 4 Mast 5 Elevating rail 6a, 6b Suspension member 7a, 7b Servo motor (elevation drive means) 8 Traveling object 15 Tilt detection means

Claims (3)

[Claims] 1. In an automatic warehouse in which a pair of opposing racks are arranged in parallel at intervals, a pair of masts provided on one rack side, an elevating rail moving along the mast, and an elevating rail. And a pair of lifting members for lifting and lowering the lifting rail, a pair of lifting driving means for driving each lifting member, and a height direction of the lifting rail. An automatic warehouse, comprising: an inclination detecting means for detecting an inclination of the object. 2. The automatic warehouse according to claim 1, wherein the elevation drive means is separately controlled according to a detection result of the inclination detection means. 3. The tilt detecting means includes a pair of detected members provided at both ends of the elevating rail, and a pair of sensors provided at the same height position of each mast for detecting the detected members. The automatic warehouse according to claim 2, wherein the automatic warehouse is operated.