JPH07208909A - Welding line detector of wheel rim - Google Patents

Abstract

PURPOSE:To accurately specify the welding line position formed at a wheel rim. CONSTITUTION:The welding line detector is provided with a turntable 4 for rotating a wheel rim 1 coaxially, a rotary encoder E for detecting the rotary position of the turntable 4, magnetic sensors 2 and 3 for detecting the magnetic characteristic change and recesses and projections of the wheel rim 1 while facing the flange of the wheel rim 1. and a data memory 12 for storing the rotary position detected by the rotary encoder E and the output of the magnetic sensors 2 and 3 making correspond to each other for one rotation of the wheel rim.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding line detecting device for specifying the position of a welding line formed on a wheel rim.

[0002]

2. Description of the Related Art In an automatic wheel rim production line, after the plate bending welding is performed, the valve is formed before the valve drilling step of the formed wheel rim and the step of inserting a disc into the wheel rim to assemble the wheel. A step of detecting the welding line position of the rim is performed. Conventionally, in detecting such a welding line, a mark sensor, a color sensor or a camera is used, a change in color tone is detected in the welding line of the wheel rim, and a signal of the detected sensor or the like is used with a preset level. The binarization process is performed and an on / off signal is output, whereby the position of the welding line is specified.

[0003]

However, dirt is often attached to the actual wheel rim other than the welding line, and this dirt exists in different places depending on the individual wheel rims. Then, due to this stain, the color tone is changed in a place other than the welding line. In addition, due to the positional relationship of the light source used in combination with a camera or the like, there is often a disturbance such as illegal reflection, or unexpected light other than the original light source entering the wheel rim. Therefore, there has been a problem that the position of the welding line cannot be correctly specified. If the position of the welding line is erroneously specified in this way, the valve will be pierced at the wrong position in the next step, resulting in a defective product. On the other hand, in order to accurately specify the welding line position by changing the binarization level, it is necessary to adjust the binarization level each time the lot is changed, and work efficiency is improved. There is a problem that it decreases. Therefore, it is an object of the present invention to provide a wheel rim welding line detection device capable of accurately detecting the welding line position of a wheel rim.

[0004]

SUMMARY OF THE INVENTION A welding line detecting device for a wheel rim according to the present invention comprises a turntable for coaxially rotating the wheel rim, a rotational position detecting means for detecting a rotational position of the turntable, and a wheel rim. The magnetic sensor includes a magnetic sensor that faces the flange and detects a change in magnetic characteristics of the wheel rim and unevenness, and a data memory that stores the rotational position detected by the rotational position detecting means and the output of the magnetic sensor in association with one rotation of the wheel rim.

[0005]

With the above construction, the wheel rim is rotated coaxially with the turntable by the turntable, the rotational position of the turntable is detected by the rotational position detecting means, and the magnetic characteristic change of the wheel rim at the rotational position is detected. The unevenness is detected by the magnetic sensor, and the rotational position and the output of the magnetic sensor are stored in the data memory for one round of the wheel rim. As a result, since data for one round of the wheel rim is acquired, it is possible to cancel influences other than the welding line and improve the accuracy of identifying the welding line position.

[0006]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram of a welding line detection device for a wheel rim according to an embodiment of the present invention. In the figure, 1 is a wheel rim, 2 and 3 are a pair of upper and lower magnetic sensors facing the flange end of the wheel rim 1 so as to face each other, 4 is a turntable for rotating the wheel rim 1 coaxially, and 5 is a turntable 4. , 6 is a motor, and this motor 6 includes a pulley 7 having a shaft 5 of a turntable 4 mounted on the shaft 5, a pulley 8 mounted on an output shaft of the motor 6, and the pulleys 7, 8. It is rotated through the timing belt 9 which is adjusted to. Reference numeral 10 is an A / D converter that digitizes the output of the magnetic sensor 2 and converts it into first magnetic data, 11 is an A / D converter that digitizes the output of the magnetic sensor 3 and converts it into second magnetic data, and E is A rotary encoder as a rotational position detecting means for detecting the rotational position of the turntable 4, and 12 is a rotary encoder E.
2 is a data memory that stores the rotational position, the first magnetic data output by the A / D converter 10 and the second magnetic data output by the A / D converter 11 in association with each other as shown in FIG. is there.

Reference numeral 13 is a motor driver for controlling the motor 6, 14 is a ROM (read only memory) storing a control program according to the flow chart of FIG.
Reference numeral 5 is a CPU (central processing unit) that executes the control program of the ROM 14 and controls each element of FIG. 1, and 16 is a RAM provided with a storage area for storing information required when executing the control program. (Random access memory), 17 is a keyboard for the user to input necessary information such as operation commands, and 18 is a CRT (cathode ray tube) for displaying the operation status to the user. Figure 2
FIG. 3 is a data configuration diagram in a data memory of a welding line detection device for a wheel rim according to an embodiment of the present invention. As shown in the drawing, a rotational position detected by a rotary encoder E and a flange end portion of the wheel rim 1 are shown. At least the first magnetic data detected by the magnetic sensor 2 above and subjected to data processing and the second magnetic data detected by the magnetic sensor 3 below the flange end portion of the wheel rim 1 and subjected to data processing are at least the wheel rim 1. It is stored in the data memory 12 for one round.

FIG. 3 is a flow chart showing the flow of the control program of the welding line detecting device for the wheel rim in one embodiment of the present invention. The operation of the welding line detection device for the wheel rim of this embodiment will be described below with reference to FIG. First, in step 1, a process of acquiring data is performed.
That is, the CPU 15 issues a command to the motor driver 13,
The motor 6 is driven. This makes the turntable 4
And the wheel rim 1 is rotated coaxially at a constant speed, magnetic data is output from the magnetic sensors 2 and 3, and each rotary position is detected by the rotary encoder E. As described above, the rotary position, the first magnetic data, The second magnetic data is stored in the data memory 12. The above operation is continuously performed for at least one round of the wheel rim 1. Next, the CPU 15
The first magnetic data and the second magnetic data in the data memory 12 are referred to, and the maximum absolute value is obtained for each (step 2). Then, the CPU 15 obtains each rotational position corresponding to each maximum value (step 3). In step 4, the difference between the rotational position corresponding to the maximum value of the first magnetic data and the rotational position corresponding to the maximum value of the second magnetic data is obtained, and this difference is compared with a preset threshold value. (Step 4). If the difference is equal to or less than the threshold value, it is interpreted that the welding line position has been correctly specified, and the average value of the two rotational positions thus obtained is specified as the welding line position (step 5). Of course, only one of the magnetic sensors 2 and 3 may be provided, and the rotational position corresponding to the maximum value of the magnetic data may be the welding line position.
It does not matter if the welding position is either the rotational position corresponding to the maximum value of the first magnetic data or the rotational position corresponding to the maximum value of the second magnetic data. On the other hand, if the above difference exceeds the threshold value, it is interpreted that the detection of the welding line position has ended abnormally, and the CPU 15 causes the CRT 18 to display a message prompting the user to re-measure (step 6).

As described above, the welding line detecting apparatus for the wheel rim of the present embodiment obtains the data for one round of the wheel rim 1 in the data memory 12 and performs the data processing on the data, for example, the wheel rim 1 If there is a periodic distortion during the manufacturing of the, it is possible to cancel the effects other than the weld line, such as excluding this periodic component from the data, and improve the accuracy of identifying the weld line position. You can The magnetic sensors 2 and 3 are the wheel rim 1.
Is to measure the magnetic characteristic change and the unevenness of the flange end portion in a vertically opposed manner, and experience shows that the flange end portion has a larger signal change at the welding line position than the other portions of the wheel rim 1. It is possible to minimize the influence of the other components on the signals of the magnetic sensors 2 and 3. Further, by using a plurality of magnetic sensors such as the magnetic sensors 2 and 3, the upper and lower flange ends of the wheel rim 1 are measured, and the detection results of both the magnetic sensors 2 and 3 are compared and examined. Even if the output of the magnetic sensor is abnormal, it is possible to suppress erroneous detection by the above comparison. In addition, the dirt on the wheel rim 1 often adheres to the flange end of the wheel rim 1, but since the flange ends are measured by the magnetic sensors 2 and 3 to avoid them, the accuracy of detection due to dirt can be reduced. The effect can be further reduced.

[0010]

The welding line detecting device for a wheel rim according to the present invention includes a turntable for rotating the wheel rim coaxially, a rotational position detecting means for detecting a rotational position of the turntable, and a wheel facing the flange of the wheel rim. Since the magnetic sensor for detecting the change in the magnetic characteristics of the rim and the unevenness and the data memory for storing the rotational position detected by the rotational position detecting means and the output of the magnetic sensor in association with one round of the wheel rim are stored, the welding is performed with high accuracy. The line position can be specified.

[Brief description of drawings]

FIG. 1 is a block diagram of a welding line detection device for a wheel rim according to an embodiment of the present invention.

FIG. 2 is a data configuration diagram in a data memory of a welding line detection device for a wheel rim according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a flow of a control program of the welding line detection device for the wheel rim in the embodiment of the present invention.

[Explanation of symbols]

 1 wheel rim 2 magnetic sensor 3 magnetic sensor 4 turntable 6 motor 12 data memory E rotary encoder

Claims (2)

[Claims] 1. A turntable for rotating a wheel rim coaxially, a rotation position detecting means for detecting a rotation position of the turntable, and a magnet for detecting a change in magnetic characteristics of the wheel rim facing the flange of the wheel rim and unevenness. A wheel rim welding line detection device, comprising: a sensor; and a data memory that stores the rotational position detected by the rotational position detection means and the output of the magnetic sensor in association with one rotation of the wheel rim. 2. The welding line detection device for a wheel rim according to claim 1, wherein the rotational position detection means is a rotary encoder.