JP2003206100A - Lift - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem in manually moving a lift base 1, wherein a display of the position of a lift base 1 by an encoder 10 is different from the actual position of the lift base 1, by manually moving a cam 14 to a position contacting with a micro switch 15 before restarting electric drive and resetting a zero point position in the encoder 10. <P>SOLUTION: This lift is provided with a position correction part 35 displaying the position obtained by a bar code on the display, when a pointer of a scale 34 attached to a support 22 supporting the lift base 21 is read and the position obtained by the bar code corresponding to the pointer is different from a position converted by the encoder 30. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting device having a screw jack for moving a lifting table in a vertical direction.

[0002]

2. Description of the Related Art FIG. 4 is a block diagram showing a conventional lifting device. In FIG. 4, 1 is a lifting platform, 2 is a column for supporting the platform 1, 3 is a column for supporting the column 2, and is vertically slidable. Support bearings, 4 are columns 2, screw jacks 5
And a support base for fixing the motor 9, 5 is a screw jack for vertically moving the lift base 1, 6 is a worm gear of the screw jack 5, 7 is a screw shaft of the screw jack 5, and 8 is a nut of the screw jack 5. Is.

Reference numeral 9 is a motor for rotating and driving the worm gear 6 of the screw jack 5. Reference numeral 10 is attached to the rotary shaft of the motor 9. The product of the number of pulses generated by the rotation of the motor 9 is subtracted from the product, and the product is subtracted. It is a rotary encoder that converts the result to the position of the lift 1.
0 has a function of displaying the position of the lift 1 on a display (not shown). Reference numeral 11 is a handle for rotating the screw shaft 7 of the screw jack 5 when manually moving the lifting table 1, 12 is a lock pin for fixing the rotation of the screw shaft 7, 13 is a manhole, and 14 is a cam showing a 0-point position, 1
When 5 comes into contact with the cam 14, 0 in the encoder 10
It is a micro switch that resets the point position.

Next, the operation will be described. First, in the case of moving the lift 1 by electric drive, the motor 9 is started. When the rotation shaft of the motor 9 starts to rotate, the worm gear 6 of the screw jack 5 rotates and the nut 8 of the screw jack 5 rotates. As a result, the nut 8 of the screw jack 5 moves up and down along the thread of the screw shaft 7, and the support base 4 and the column 2 that fix the screw jack 5 move up and down. Move in the direction.

On the other hand, when manually moving the lifting table 1, the lock pin 12 that fixes the rotation of the screw shaft 7 of the screw jack 5 is removed, and a person rotates the handle 11. As a result, the screw shaft 7 rotates, the nut 8 moves up and down along the thread of the screw shaft 7, and the support base 4 and the support column 2 that fix the screw jack 5 move up and down. The table 1 moves up and down.

Here, the encoder 10 generates a pulse each time the rotating shaft of the motor 9 rotates by a predetermined angle,
The number of pulses is subjected to product subtraction, and the product subtraction result is converted to the position of the lift 1. Then, the encoder 10 displays the position of the lift 1 on a display (not shown).

However, when the elevator table 1 is moved by manual drive, the encoder 10 attached to the rotary shaft of the motor 9 does not rotate, so the position of the elevator table 1 displayed on the display is updated. There is no such thing. Therefore, when the lift base 1 is moved by manual drive, the position of the lift base 1 displayed on the display is different from the actual position of the lift base 1. Therefore, before the electric drive is restarted, the cam is manually driven. 14 for micro switch 1
It is necessary to move to the position where it contacts 5 and reset the 0 point position in the encoder 10. That is, the product subtraction result accumulated in the encoder 10 is reset,
It is necessary to eliminate the erroneous display of the position of the lift 1.

[0008]

Since the conventional lifting device is constructed as described above, the lifting table 1 is manually driven.
When is moved, a phenomenon occurs in which the position display of the lift 1 by the encoder 10 is different from the actual position of the lift 1.
Therefore, before restarting the electric drive, it is necessary to manually move the cam 14 to a position where it comes into contact with the micro switch 15 and reset the zero point position in the encoder 10. However, resetting the 0-point position is a troublesome work and requires a long time, and if the resetting of the 0-point position is forgotten, there is a problem that the position of the lift 1 is erroneously displayed.

The present invention has been made in order to solve the above problems, and provides an elevating device capable of preventing erroneous display of the position of the elevating table even if the elevating table is moved by manual drive. With the goal.

[0010]

In the lifting device according to the present invention, the scale of a scale attached to a column supporting the lifting platform is read, and the position indicated by the scale is different from the position calculated by the position calculating means. In this case, correction means for displaying the position indicated by the scale on the display means is provided.

In the lifting device according to the present invention, when the position indicated by the scale is different from the position calculated by the position calculating means,
The offset position serving as the reference for position calculation in the position calculation means is corrected by the amount of the position error.

In the lifting device according to the present invention, when a bar code recording position information is also written on each scale,
The bar code is analyzed to grasp the position of the lift.

The lifting device according to the present invention comprises a correction means using an optical reader for optically reading the scale of the scale and a scanner for reading the bar code corresponding to the scale.

In the lifting device according to the present invention, when the length of each graduation differs depending on the position of the lifting table, the length of the graduation is measured to grasp the position of the lifting table.

The lifting device according to the present invention comprises correction means using an optical reader for optically reading the scale of the scale and measuring the length of the scale.

In the lifting device according to the present invention, when a marker is also written on each scale, the position of the lifting platform is grasped in consideration of the number of markers that are also written.

The lifting device according to the present invention uses an optical reader that optically reads the scale of the scale, measures the length of the scale, and reads the number of markers written on the scale. It constitutes a correction means.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. Embodiment 1. 1 is a block diagram showing an elevating device according to Embodiment 1 of the present invention. In the figure, 21 is an elevating table, 22 is a column for supporting the elevating table 21, and 23 is a column 22.
And a support bearing that slides in the vertical direction, 24 is a support base that fixes the support column 22, the screw jack 25, and the motor 29, 25 is a screw jack that moves the lift base 21 in the vertical direction, and 26 is a screw jack. 25 is a worm gear, 27 is a screw shaft of the screw jack 25, and 28 is a nut of the screw jack 25.

Reference numeral 29 is a motor (electric drive means) for rotationally driving the worm gear 26 of the screw jack 25, 30
Is a rotary type encoder (position calculation means, which is attached to the rotary shaft of the motor 29, performs product subtraction of the number of pulses generated with the rotation of the motor 29, and converts the product subtraction result into the position of the lift table 21. The encoder 30 has a function of displaying the position of the lift 21 on a display (not shown). 31 is the screw shaft 2 of the screw jack 25 when the lift table 21 is manually moved.
A handle (manual drive means) for rotating 7; 32, a lock pin for fixing rotation of the screw shaft 27; and 33, a manhole.

Reference numeral 34 denotes a scale attached to the column 22, and an optically readable scale and a bar code recording position information are attached to the scale 34 in pairs. Reference numeral 35 denotes a position correction unit (correction means) that reads the scale of the scale 34 and, when the position indicated by the scale is different from the position converted by the encoder 30, displays the position indicated by the scale on the display.
The position correction unit 35 is composed of an optical reader for optically reading the scale of the scale 34 and a scanner for reading a bar code corresponding to the scale.

Next, the operation will be described. First, when the lift 21 is moved by electric drive, the motor 29 is started. When the rotation shaft of the motor 29 starts to rotate, the worm gear 26 of the screw jack 25 rotates and the nut 28 of the screw jack 25 rotates. As a result, the nut 28 of the screw jack 25 is attached to the screw shaft 2
7 moves up and down along the screw threads of 7, and the support base 24 and the support 22 fixing the screw jack 25 move up and down, so that the lift base 21 moves up and down.

On the other hand, when manually moving the lifting table 21, the lock pin 32 fixing the rotation of the screw shaft 27 of the screw jack 25 is removed, and a person rotates the handle 31. As a result, the screw shaft 27 rotates, the nut 28 moves in the vertical direction along the thread of the screw shaft 27, and the support base 24 and the column 22 that fix the screw jack 25 move up and down. The table 21 moves up and down.

Here, the encoder 30 generates a pulse each time the rotation axis of the motor 29 rotates by a predetermined angle, performs product subtraction on the number of the pulses, and outputs the product subtraction result to the position of the lift table 21. Convert. And the encoder 30
Displays the position of the lift 21 on a display not shown.

However, when the lift table 21 is moved by manual drive, the encoder 30 attached to the rotary shaft of the motor 29 does not rotate, so the position of the lift table 21 displayed on the display is updated. There is no such thing. Therefore, when the lift table 21 is moved by manual driving, a phenomenon occurs in which the position of the lift table 21 displayed on the display is different from the actual position of the lift table 21.

However, in the first embodiment, erroneous display of the position of the lift table 21 is prevented as follows. That is, the optical reader of the position correction unit 35 optically reads the scale of the scale 34 (reads the scale at the same height as the position correction unit 35), and the scanner of the position correction unit 35 reads the bar corresponding to the scale. By reading the code, the position of the lift 21 is grasped from the position information recorded in the bar code.

If the position of the lift table 21 obtained from the position information is different from the position converted by the encoder 30, the position correction section 35 moves the lift table 2 obtained from the bar code.
Display position 1 on the display. In addition, the position correction unit 35 calculates an error amount between the position of the lifting table 21 obtained from the bar code and the position converted by the encoder 30, and uses the error amount of the position as a reference for position calculation in the encoder 30. Correct the offset position. That is, the product subtraction result accumulated in the encoder 10 is corrected by the position error, and the position error converted by the encoder 30 next time is eliminated.

As is clear from the above, the first embodiment
According to the above, when the scale of the scale 34 attached to the support column 22 supporting the lift 21 is read and the position obtained from the bar code corresponding to the scale is different from the position converted by the encoder 30, the bar is changed. Position correction unit 3 for displaying the position obtained from the code on the display
Since it is configured to provide 5, it is possible to prevent erroneous display of the position of the lift table 21 even if the lift table 21 is moved by manual driving. Further, an error amount between the position of the lifting platform 21 obtained from the barcode and the position converted by the encoder 30 is calculated, and the offset position serving as the reference for position calculation in the encoder 30 is corrected by the error amount of the position. With this configuration, it is possible to omit the troublesome resetting work for the encoder 30.

Embodiment 2. 2 is a block diagram showing a lifting device according to Embodiment 2 of the present invention.
The same symbols as those in FIG. If the scales 36 have different lengths according to the position of the lifting table 21, the lengths of the scales are measured to measure the lifting table 21.
Is a position correction unit (correction means) for grasping the position of the scale, and the position correction unit 36 is composed of an optical reader for optically reading the scale of the scale 34 and measuring the length of the scale.

Next, the operation will be described. In the first embodiment, the position correction unit 35 optically reads the scale of the scale 34 and also reads the bar code corresponding to the scale, so that the position of the lift table 21 can be determined from the position information recorded in the bar code. Although the position is grasped, the position correction unit 36 optically reads the scale of the scale 34, measures the length of the scale, and grasps the position of the lift 21 from the measurement result. Good. As a result, the same effect as that of the first embodiment can be obtained.

Embodiment 3. 3 is a block diagram showing a lifting device according to Embodiment 3 of the present invention.
The same reference numerals as those in FIG. 2 indicate the same or corresponding portions, and therefore their explanations are omitted. 37, if markers are also written on each scale, take into account the number of markers that are also written, and lift 2
1 is a position correction unit (correction means) for grasping the position of 1. The position correction unit 37 optically reads the scale of the scale 34, measures the length of the scale, and is also written on the scale. It consists of an optical reader that reads the number of markers.

Next, the operation will be described. Although the position correction unit 36 measures the length of the scale of the scale 34 and grasps the position of the lift 21 from the measurement result in the second embodiment, a marker is also written on each scale. In this case, the position correction unit 37 may count the number of markers that are also written, and grasp the position of the lift 21 based on the scale length and the number of markers. As a result, the same effect as in the second embodiment can be obtained.

[0032]

As described above, according to the present invention, when the scale of the scale attached to the column supporting the elevator is read and the position indicated by the scale is different from the position calculated by the position calculating means. Since the correction means for displaying the position indicated by the scale on the display means is provided, there is an effect that even if the lift table is moved by manual drive, erroneous display of the position of the lift table can be prevented.

According to the present invention, when the position indicated by the scale is different from the position calculated by the position calculating means, the offset position serving as the reference for position calculation in the position calculating means is corrected by the error of the position. Therefore, there is an effect that it is possible to omit the troublesome resetting work for the position calculating means.

According to the present invention, when the bar code recording the position information is also written on each scale, the bar code is analyzed to grasp the position of the elevator, so that it can be easily carried out. There is an effect that the position of the lifting platform can be grasped.

According to the present invention, since the correction means is constituted by using the optical reader for optically reading the scale of the scale and the scanner for reading the bar code corresponding to the scale, the structure is complicated. Instead, there is an effect that the position of the lifting platform can be grasped.

According to the present invention, when the length of each graduation differs depending on the position of the lift, the length of the graduation is measured to grasp the position of the lift, so that the lift can be easily moved up and down. There is an effect that the position of the table can be grasped.

According to the present invention, since the correction means is constructed by using the optical reader for optically reading the scale on the scale and measuring the length of the scale, the ascending / descending without causing the configuration to be complicated. There is an effect that the position of the table can be grasped.

According to the present invention, when a marker is also written on each scale, the position of the lifting platform is grasped in consideration of the number of the markers that are also labeled, so that the position of the lifting platform can be easily adjusted. There is an effect that can be grasped.

According to the present invention, the correction means is provided by using the optical reader which optically reads the scale of the scale, measures the length of the scale, and reads the number of the markers written on the scale. Since the above is configured, there is an effect that the position of the lifting table can be grasped without inviting the configuration to be complicated.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a lifting device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing an elevating device according to Embodiment 2 of the present invention.

FIG. 3 is a configuration diagram showing an elevating device according to Embodiment 3 of the present invention.

FIG. 4 is a configuration diagram showing a conventional lifting device.

[Explanation of symbols]

21 Elevating Table, 22 Supports, 23 Support Bearing, 24 Support, 25 Screw Jack, 26 Worm Gear, 27 Screw Shaft, 28 Nut, 29 Motor (Electric Drive Means), 30 Encoder (Position Calculation Means, Display Means), 31 Handle (manual drive means), 32 lock pin, 33 manhole, 34 scale, 35, 3
6,37 Position correction unit (correction means).

Claims (8)

[Claims] 1. An electric drive means for rotationally driving a gear shaft of a screw jack to vertically move an elevator base; a manual drive means for rotationally driving a screw shaft of the screw jack to vertically move the elevator base; An elevating device provided with position calculating means for detecting the rotation angle of the rotating shaft of the electric drive means and calculating the position of the lift from the rotation angle, and display means for displaying the position calculated by the position calculating means. In, reading the scale of the scale attached to the column supporting the lifting platform, and if the position indicated by the scale is different from the position calculated by the position calculation means, the position indicated by the scale is displayed on the display means. An elevating device, characterized in that it is provided with a correcting means. 2. The correcting means, when the position indicated by the scale is different from the position calculated by the position calculating means, corrects the offset position serving as a reference for position calculation in the position calculating means by an error amount of the position. Claim 1 characterized by
Lifting device described. 3. The correcting means, when a bar code recording position information is also written on each scale, analyzes the bar code to grasp the position of the elevator. Alternatively, the lifting device according to claim 2. 4. The elevating device according to claim 3, wherein the correction means is constituted by an optical reader for optically reading the scale of the scale and a scanner for reading the bar code corresponding to the scale. 5. The correcting means, when the length of each graduation differs depending on the position of the lifting table, measures the length of the graduation to grasp the position of the lifting table. Alternatively, the lifting device according to claim 2. 6. The elevating device according to claim 5, wherein the correction means is configured by using an optical reader for optically reading the scale of the scale and measuring the length of the scale. 7. The elevating device according to claim 5, wherein, when a marker is also written on each scale, the correcting means grasps the position of the lifting platform in consideration of the number of the markers that are also written. . 8. The correction means is constructed by using an optical reader for optically reading the scale of the scale, measuring the length of the scale, and reading the number of markers written on the scale. The lifting device according to claim 7.