JP2536408Y2 - Lifter device with chain elongation correction means - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifter device for vertically moving a lifter on which an object is placed and positioning the lifter at a predetermined position corresponding to a storage section such as a three-dimensional stocker.

[0002]

2. Description of the Related Art Many machining systems for machine tools have a stocker for storing a material work or a finished work. In this stocker, a three-dimensional stocker in which a plurality of storage portions are formed not only in a traveling direction but also in a vertical direction in order to store a large number of finished products and the like with a small floor area is often used. It is well known that a stacker crane that can move and move up and down is used to transport an object such as a material work or a finished product work to the three-dimensional stocker. Many of the stacker cranes use a chain as a member for transmitting a driving force to a lifter on which an object to be conveyed is placed, and a sprocket for the chain is rotated by a motor to move up and down. As a control method of this lifter, a method of setting an origin at a predetermined position in the vertical direction, numerically controlling the lift position of the lifter by a movement command of a predetermined movement amount in a coordinate system based on the origin, There is a method in which a stop switch is provided at each stop position of the lifter corresponding to each storage section, and the elevation position of the lifter is controlled by operating the stop switch. In the control method by the operation of the stop switch, a deceleration switch for ascending, a stop switch, a deceleration switch for descending, and a stop switch are required at one stop position in order to secure stop accuracy, and the control becomes complicated. The vicinity of the stop switch moves at a deceleration speed, so that it takes a long time to move. Therefore, it is rarely used for a lift mechanism of a lift of a stacker crane.

[0003]

However, it is inevitable that the chain will be stretched due to wear of pins and bushes due to long-term use. For this reason, in the method of performing numerical control with a movement command based on a coordinate system based on the origin, in advance, corresponding to the storage unit,
Even if the programmed movement command value is raised or lowered, an error occurs between the stop position of the lift and the height of the storage section. That is, even if the rotational position of the sprocket or the encoder of the servomotor is controlled, an error in the stop position will occur if the chain beyond that is elongated. If an error occurs in the stop position, an object is not transferred between the stacker crane and the stocker, an alarm is generated, the operation stops, and the unmanned operation of the processing system stops. occured. The present invention has been made in view of the above-described problems, and when an error occurs in a stop position of a lifter due to chain elongation, the error can be automatically corrected, and therefore, maintenance can be performed. It is an object of the present invention to provide a lifter device that can be easily maintained and managed by eliminating the need for a lifter device.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention solves the above-mentioned problem by transferring a transferred object between a shelf having a plurality of storage sections provided in a three-dimensional shape for storing the transferred object. What is claimed is: 1. A lifter device for moving a lifter in an elevating direction so that a height of a lifter capable of storing an object to be transported and the storage unit is made coincident with each other so as to be capable of exchanging, and a main body of the lifter device; A chain wound in a loop in the vertical direction of the main body of the device, and provided movably with respect to the lifter device main body, both ends of which are fixed to the lifter guided by the guide portion of the lifter device main body; provided in the main body of the lifter device, a drive means for positioning driven by numerically controlling the chain, lifter lifting times
The number of elevating and lowering counters
The number of lifter lifts is estimated based on the count
When the set number of times is reached, a chain elongation correction is indicated.
That the chain elongation correction instruction means (5, 31), based on the instructions of the chain elongation correction instruction means, and positioning the lifter in position, when there is an error due to elongation of the chain by this positioning, the lifter Position detecting means for detecting that the stop position has changed by a predetermined distance or more from the predetermined position, and correcting the origin position of the lifter or shifting the coordinate system when the change of the stop position is detected by the position detecting means. The present invention is configured to include a chain elongation correcting means for performing the elongation correction of the chain, and a central processing unit for centrally controlling the respective means.

[0005] The rise of the lifter to every movement command of the lifting direction there Ru
The number of descents is counted, and based on this count,
It is determined whether or not the set number of times has been reached . When the number of times of ascending and descending reaches the set number of times, the operation of the chain elongation correction is executed. First, a movement command to a home position is executed.
In this localization value, the localization value detection means detects whether or not an error has occurred in the stop position for a predetermined amount or more due to the elongation of the chain. If an error is detected, the home position return operation is performed, and the home position return operation is performed. The position is corrected or the shift amount of the coordinate system is rewritten to correct the error based on the chain elongation.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a stacker crane, and FIG.
FIG. 3 is an enlarged view of a part B in FIG. In FIG. 1, a stacker crane 7 is driven by a servo motor (not shown) on a lower rail 8 disposed along a three-dimensional stocker (not shown), and is rotatably supported on a base 10 by wheels 9a. , 9b. Pillars 11a and 11b are provided side by side on the base 10, and
The lifter 13 on which the transported object W and the like are placed can be moved up and down by using a and 11b as guides in the vertical direction. Rollers 15 a, rotatably supported by support portions 13 a of the lifter 13, sandwich the pillars 11 a, 11 b from two sides in two directions perpendicular to the plane of the drawing, respectively.
15b and rollers 16a and 16b are provided. Side rollers are provided at positions corresponding to the rollers 15a and 15b and the rollers 16a and 16b on the side of the lifter 13, and roll on the surfaces of the columns 11a and 11b. That is, the lifter 13 applies the surfaces of the pillars 11a and 11b to the rollers 15a and 15b,
The rollers 16a, 16b and side rollers are movable only in the vertical direction. The lifter 13 is provided with a transport body 12 that transports the transported object W in a direction orthogonal to the paper surface by a driving body (not shown) and exchanges the transported object W with a three-dimensional stocker. Carrier 12
An article to be transported W is placed on the top.

[0007] Such a lifter 13 is suspended by a chain 14 and can be moved up and down. That is, the chain mounting portions 17a, 1 provided on the upper portion of the lifter 13
Chains 14a, 14b with one end attached to 7b
Are sprockets 18a, 18b, 18c, 18d, 1
8e, 18f, 18g or sprocket 18b, 1
8c, 18d, 18e, 18f, and 18g. The other end of the chain is attached to a chain attaching portion 17c (see FIG. 2) formed on the side of the lifter 13 so as to always apply a tensile force to the chain 14. That is, as shown in FIG. 2, the shaft body 42 to which the other end of the chain 14 is fixed is movable in the axial direction with respect to the chain attachment portion 17 c of the lifter 13, and is axially moved by the biasing member 43. The chain 14 is always urged, so that even if the chain 14 is stretched by this urging force, it can be absorbed. Reference numeral 19 denotes a servomotor that drives the chain 14 by rotating the sprocket 18e via the speed reducer 39. The servo motor 19, the chain 14, and each sprocket constitute a drive mechanism for moving the lifter 13 in the elevating direction.

The upper part of the pillars 11a and 11b is the ceiling frame 2.
0 and are connected to the aforementioned sprockets 18a, 18
8b and 18c are rotatably attached to the ceiling frame 20. Further, upper rollers 21a and 21b are rotatably attached to the upper portion of the ceiling frame 20 with respect to the ceiling frame 20.
b, an upper rail 2 arranged on the ceiling or the like indoors in cooperation with an upper roller (not shown) arranged rearward in the drawing.
2 is sandwiched from both sides so that it can run and supports the upper part of the stacker crane. The stacker crane 7 is supported so as to be able to travel freely in cooperation with the wheels 9a and 9b on the lower rail 8.

Reference numeral 23 denotes a control device for controlling the stacker crane 7, and various switches necessary for manual operation such as a push button switch for raising, a push button switch for lowering, and a push button switch for stopping are provided. ing.
Reference numeral 24 denotes an operation table on which an operator rides, and reference numeral 25 denotes a handrail. As shown in FIG. 3, an origin deceleration dock 26 and a fixed-position dock 29 are fixed to the lifter 13 with bolts at predetermined intervals. An origin deceleration detection switch 27 and a fixed position detection switch 28 are fixed to the column 11a at positions facing the respective docks via stays 27a and stays 28a. The fixed position dock 29 is the lifter 13.
Is moved to the home position by the NC data, and when the lifter 13 causes an error of a predetermined amount or more from the initial adjustment position due to the extension of the chain, the detection state of the home position detection switch 28 is changed from the ON state to the OFF state. Attached to. The fixed position detected by the fixed position dock 29 and the fixed position detection switch 28 is such that the relationship between the servo motor 19 for driving the lifter 13 and the urging member 43 absorbing the extension of the chain 14 is closest, and 14 is provided at a position where the extension of 14 is detected largely. The origin deceleration dock 26 reduces the descending speed of the lifter 13 to the origin setting speed when the lifter 13 descends from above and the state of the origin deceleration detection switch 27 becomes ON from OFF. If the movement continues, the origin deceleration detection switch 27
The origin deceleration dock 26 passes above, and the state changes from ON to OFF. Then, the lifter 13 is stopped at the one-rotation signal output position of the servo motor 19 after the switch is turned off, and this position is set as the origin.

FIGS. 4 (a) and 4 (b) are views showing the main configuration of the present invention. In FIG. 4 (a), reference numeral 5 denotes a central processing unit a (hereinafter, referred to as CPU), 5 ₁ is its main bus. 31 is a system program memory,
A system program for controlling the operation of the stacker crane 7 according to a command from the host computer 51 or the like is stored. An NC data memory 32 stores NC data for operating the stacker crane downloaded from the host computer 51 via the interface 51a. Reference numeral 50 denotes a programmable controller, which includes an origin deceleration detection switch 27 and a localization value detection switch 2.
8 is connected, and the detection signal is sent to the CPU 5 via the interface 50a. Reference numeral 33 denotes a chain elongation correcting means which detects whether or not there is an error in the stop position due to the elongation of the chain and causes the lifter 13 to perform an origin return operation when an error due to elongation occurs, and stores a program for performing elongation correction. is there. Reference numeral 19 denotes a servomotor which is a driving body of the lifter 13 in the elevating direction,
5 is connected via an amplifier (amplifier) 36, and feeds back the speed position to raise and lower the lifter 13 to a predetermined position.

The operation of the above configuration will be described with reference to the flowcharts of FIGS. 5 and 6 (a) showing the control procedure of the present invention. The CPU 5 determines whether or not there is an operation command to operate the stacker crane 7, and if there is no operation command, waits for the command,
If yes, the process proceeds to step S62 (step S6).
1). Then, it is determined whether or not the operation command is a moving command in the vertical direction, and if the moving command is not the vertical moving command, that is, the moving command of the lifter device, the command is executed, and step S is executed.
Proceed to 67 (step S62). If it is a movement command of the lifter device, the current number of times of ascending and descending is compared with the number of times set in the parameter memory and the like, and it is determined whether or not the number of ascending and descending has reached the set number of times (step S6).
3). If it has reached, after executing the command, the program in the chain elongation correcting means 33 is read and executed (step S64), and the up / down counter is set to 0.
(Step S65). If the number of times of ascending and descending has not reached the set number of times, the instruction is executed, and then the number of times of ascending and descending is counted up (step S66). In step S67, it is determined whether or not the stacker crane is operating. If the stacker crane is operating, the processes in and after step S61 are repeated, and if not, the execution of the NC data is terminated.

The processing of the program in the chain elongation correcting means 33 which is read and executed in step S64 will be described with reference to the flowchart of FIG.
First, a movement command to a home position is executed (step S7).
1). After the movement to the home position, it is determined whether or not the state of the home position detection switch 28 is ON (step S71). If it is ON, the execution of this program ends. If it is not in the ON state, it means that chain elongation has occurred, and the process proceeds to step S73 (step S72). In step S73, after the lifter is once raised to the predetermined position, an origin return command is executed (step S73). In order to use the origin position set by the origin return as a reference, the coordinate system is set with this position set to 0 (step S74), and the execution of this program ends. Thereafter, the lifter 13 is moved in the machine coordinate system based on the origin position.
Is numerically controlled and positioned at each stocker position.

Next, another embodiment will be described with reference to FIGS. 4 (b) and 6 (b). The same means, memory, and the like as those in the above-described embodiment are denoted by the same reference numerals, and detailed description is omitted. In FIG. 4B, reference numeral 52 denotes a display counter of the current position of the machine coordinate system in the elevating direction,
3 is displayed. Reference numeral 53 denotes a coordinate system offset memory that stores an offset amount that is a coordinate system in which the coordinate system in the vertical direction is offset from the machine coordinate system. FIG.
The processing of another embodiment will be described according to (b). Steps S71 to S73 perform the same processing as in the above-described embodiment, and a description thereof will be omitted. If it is determined that chain elongation has occurred, an origin return command is issued to the lifter 13 in step S73. At this time, even if the lifter 13 returns to the origin, the current position display counter 5
2 does not become 0 and a numerical value remains. The CPU 5 reads the numerical value of the current position display counter 52 and writes it in the coordinate system offset memory 53 (step S8).
1). Then, the process ends. At the time of the next movement in the ascending and descending directions, since the movement is performed by numerical control in the coordinate system shifted by the numerical value of the coordinate system offset memory 53, the chain elongation can be corrected. In the above, the explanation has been given of the lifter device of the stacker crane, but the present invention is not limited to this, and any device that transmits the driving force of the drive body that is numerically controlled using a chain can be applied as it is. It is.

As described above, according to the present invention, even if an error occurs in the stop position of the lifter due to the elongation of the chain, the number of elevations of the lifter is reduced to the preset number of times.
When it reaches, an error is detected by the operation of the chain elongation correction means
Correction of errors detected by the means is performed periodically and automatically.
Is performed by the operator to adjust the stop position, etc.
Without being present, the lifter will always stop exactly in place. Therefore, it is possible to maintain the adjustment of the stop position becomes unnecessary, and easy lifter device maintenance, riffs by chain elongation
Data can be reliably prevented beforehand.
You .

[Brief description of the drawings]

FIG. 1 is a front view of a lifter device.

FIG. 2 is an enlarged view of a portion A shown in FIG.

FIG. 3 is an enlarged view of a portion B shown in FIG.

FIG. 4 is a block diagram showing a main configuration of the present invention.

FIG. 5 is a flowchart showing a control procedure of the present invention.

FIG. 6 is a flowchart showing a procedure for correcting chain elongation according to the present invention.

[Explanation of symbols]

 Reference Signs List 5 Central processing unit (CPU) 7 Stacker crane 10 Base 11a, 11b Column 13 Lifter 14, 14a, 14b Chain 17, 17a, 17b Chain mounting portion 18a-18g Sprocket 19 Servo motor 23 Control device 26 Origin deceleration dock 27 Origin deceleration Detection switch 28 Fixed position detection switch 29 Fixed position dock 31 System program memory 32 NC data memory 33 Chain elongation correction means 43 Biasing member 50 Programmable controller 51 Host computer W Workpiece

Claims (1)

(57) [Scope of request for utility model registration] A lifter capable of storing an object to be transported between a shelf having a plurality of storage sections provided in a three-dimensional shape for storing the object to be transported. And a lifter device for moving the lifter in the elevating direction so as to match the height of the storage portion with the main body of the lifter device. The lifter device is wound in a loop shape in the vertical direction of the main body of the lifter device,
A chain movably provided with respect to the lifter device main body, and both ends of which are fixed to the lifter guided by the guide portion of the lifter device main body; Driving means for driving and positioning by control, and a lift counter for counting the number of lifts of the lifter
And the lifter based on the count number
When the number of vertical movements reaches the preset number, the chain
A chain elongation correction instruction means for instructing a fine correction, based on the instructions of the chain elongation correction instruction means, and positioning the lifter in position, when there is an error due to elongation of the chain by the positioning stop of the lifter position is a position detecting means for detecting a change over a predetermined distance from the predetermined position, when the change in the stop position the position detecting means is detected,
Chain elongation correction means for correcting the origin position of the lifter or shifting the coordinate system to perform chain elongation correction; and a central processing unit for integrally controlling the respective means. Lifter device.