JPH0458106A - Method and device for detecting angle of steel cord - Google Patents

Abstract

PURPOSE:To detect the cord angle of a steel-reinforced rubber sheet by a nondestructive method with simple constitution by finding the interval between last and current code detection signals which are outputted when the steel code is passed, and finding the rotational angle where the variation tendency of the code detection interval is inverted. CONSTITUTION:When a cord detection sensor 4 passes a point (p), a cord detec tion signal (s) is outputted, a rotational angle signal is stored, and a counter begins to count a clock signal (c). Then when the cord detection sensor 4 reaches a point (q), similar processing is performed and the counted value tauof the counter is outputted. Then the counter is reset and begins to count a new clock signal (c). A central processing unit inputs the counted value tau to an address corresponding to a rotational angle signal at the point (p). This operation is repeated while the rotational angle signal thetamax. A value which is minimum at the position where the angle theta and code angle alpha are complemen tary to each other is employed as the counted value tau, so the current angle thetaof rotation is found to find the cord angle alpha.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and device for detecting the angle of a steel cord, and more particularly, to a method and device for detecting the cord angle of a steel-reinforced rubber sheet. .

[Conventional technology]

For example, steel cord-reinforced rubber sheets used in EVs, pneumatic rubber tires, conveyor belts, etc. are made of embedded steel wires arranged in parallel at equal intervals at a certain angle to the longitudinal direction of the rubber sheet. It is well known that

In order to detect variations in the arrangement interval (pitch) of steel cords, the present inventor first installed two magnets at the tip of a permanent magnet.
He invented a device that scans a steel-reinforced rubber sheet with a metal sensor equipped with Hall elements, and detects variations in the pitch of steel cords from the waveform of the signal output by the Hall elements, and patented it as Japanese Patent Publication No. 2-13895. I have applied.

[Problem to be Solved by the Invention] By the way, steel-reinforced rubber sheets have a problem in that if the cord angles are not arranged at a predetermined angle, products such as tires using the rubber sheets cannot exhibit the desired performance. There is. Incidentally, a steel reinforced rubber sheet is manufactured by first manufacturing a wide sheet, cutting it into strips, and joining them together in the longitudinal direction. Therefore, even if the above-mentioned angle is made accurately in the manufacturing process of the original sheet, it cannot be cut accurately when cutting into the shape of crushed strips, and the sheets are cut into deformed shapes and processed in the splicing process. There is a risk that errors may occur in the cord angle during subsequent processes such as the sulfurization process. However, a device for detecting the cord angle has not been provided so far, and at present, the cord angle is used without being measured.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a steel cord angle detection method and apparatus that can detect the cord angle of a steel-reinforced rubber sheet with a simple configuration and by non-destructive means.

[Means for Solving the Problems] To achieve the above object, the steel cord angle detection method of the present invention non-contactly detects a steel cord attached to a rotating arm that can scan the entire width of a steel reinforced rubber sheet. When the code detection sensor outputs a code detection signal when it passes the steel cord embedded in the rubber sheet, it reads the rotation angle from the scanning start position of the rotary arm and also compares the previous and current times. The interval between the code detection signals and the code detection interval is determined, and the rotation angle at which the change tendency of the code detection interval is reversed is determined.

The code detection sensor that can be used is not particularly limited, but for example, a sensor that combines a Hall element and a permanent magnet,
In addition to using a sensor that uses an X-ray beam, it is also possible to use a sensor that detects the position of the steel cord by detecting it with a laser beam and processing it with a computer, since the position where the steel cord is present will be somewhat raised.

When the steel-reinforced rubber sheet is turned over, the direction in which the steel cords are arranged is reversed symmetrically with respect to the longitudinal direction of the rubber sheet. Therefore, when the rotary arm is rotated across the width direction of the rubber sheet, if the surface that generates the rotation angle that matches the cord angle is placed on the front side, the cord will be detected at the position where the rotary arm matches the cord placement direction. The distance that the sensor passes through the steel cord is minimal. In addition, when this is turned over, the distance between the cord detection sensor and the steel cord is maximized when the rotary arm is arranged at right angles to the steel cord. An arrangement in which the distance between the cord detection sensor passing through the steel cord is the minimum is better than an arrangement in which the distance between the cord detection sensors is the maximum because the angle reading interval is shorter, and accuracy is improved.

The code detection interval can be detected as a difference in angle at the time of code detection. However, in this case, there is a risk that the angle detection error will reduce the accuracy of the code detection interval value. Therefore, if the rotary arm is rotated at a constant speed and the code detection interval is detected in terms of time width, the angle can be accurately detected without being affected by the angle detection error.

The structure of the steel cord angle detection device of the present invention using the above-mentioned means for detecting the cord detection interval in terms of time width rotates a rotary arm equipped with a cord detection sensor that non-contactly detects the buried position of the steel cord. A steel-reinforced rubber sheet is placed at a position where the code detection sensor can scan the entire width, and a rotation angle sensor consisting of a constant speed rotation drive device and a rotary encoder that detects the rotation angle from the scanning start position is installed as described above. The output signal of the code detection sensor is attached to the rotary arm and is applied to a conversion circuit that converts the output signal into a binary signal, and the output signal of the conversion circuit is applied to the code angle calculation means and the counter. When the signal is given, the angle signal output from the angle scanner is given to the storage means,
The counter starts counting clock signals when the code detection signal is given, and when the next code signal is given,
The counting result is given to the storage means, the count value is reset and counting starts anew, and when the rotation angle sensor outputs the maximum rotation angle signal, the angle signal and the count signal stored in the storage means are sequentially input. A code angle detection section is provided for outputting the rotation angle at which the change tendency of the count signal is reversed to the display means.

[Example] The steel cord angle detection means of the present invention will be specifically explained below with reference to the drawings.

The steel cord angle detection device of the present invention shown in FIG. 1 has a steel-reinforced rubber sheet l placed on a mounting section 2, and a cord detection sensor 4 constructed by combining a Hall element and a permanent magnet at the tip. The attached rotary arm 6 is rotated in the direction of the white arrow in the figure by a rotary drive device 8 consisting of a step motor, and a rotation angle signal θ is output from a rotation angle sensor 10 consisting of a rotary encoder linked to the rotation shaft 7. , a cord detection signal S outputted when a cord detection sensor 4 consisting of a Hall element passes through a steel cord 12 embedded in a steel reinforced rubber sheet 1 is inputted to a cord angle calculation section 14.

The mounting section 2 is provided with a stand 16 on which the steel reinforced rubber sheet 1 is placed, and a guide 18 for accurately arranging the steel cord 12 on the stand 16.
A support portion 20 that rotatably supports the rotary arm 6 is attached to an extension portion (not shown) of the rotary arm 6 . Note that 22 in the figure is a screw hole for fixing the support portion 20 to the stand 16.

The rotary drive device 8 is connected to the rotary arm 6 through a coupling 24 and is driven by a servo controller 26 . The servo controller 26 performs feedback control that feeds back the angle signal θ output by the rotation angle sensor 10.

When the controller 26 starts, first, the rotating arm 6
is moved to the 0° angle position (in the width direction of the rubber sheet 1), and then the rotating arm 6 is rotated at a constant speed in the direction of the white arrow, so that the angle signal θ is applied to the side edge of the steel reinforced rubber sheet 1. It is configured to stop when reached.

The code angle calculation unit 14 in FIG. 1 is constituted by a computer, and the code detection signal S is amplified by an AC amplifier 28, and then converted into a pulse signal S by a binarization converter 30. Signal to counter 32 and I
Give 10 boats 34. The central processing unit 36 is I10
The pulse signal S input to port 34 is used as an angle reading (sampling) signal. That is, the rotation angle signal θ of the rotary arm 6 when the cord detection sensor 4 detects the steel cord 12 is stored in the memory 38. The binary converter 30 outputs a pulse at the rising edge of the code detection signal, and is further provided with a circuit element that shapes the waveform by setting a certain threshold value and saturating the signal strength at a certain level.

In addition to the pulse signal S, the counter 32 also contains:
The clock signal C output from the clock 40 is input, the number of clock signals from the input of the pulse signal S to the input of the next pulse signal is counted (integrated), and this count signal τ is sent to the I10 boat 34. is given to the angle signal θ and stored in the memory 38 in correspondence with the angle signal θ. The rotating arm 6 rotates in the rotation range - the maximum angle θ that the rotation angle sensor 10 can take,
After outputting X, the central processing unit 36 calculates the code angle θ from the angle signal θ and the count signal τ stored in the memory 38.

The principle by which the central processing unit 36 calculates the code angle α from the angle signal θ and the count signal τ will be explained with reference to FIGS. 2 and 3. In FIG. 2, 0 is the fineness of the rotating arm 6, and 40
is a locus along which the code detection sensor 4 moves. Now, when the code detection sensor 4 passes the point p, the code detection sensor 4 outputs the code detection signal S as described above. At this time, the rotation angle signal θ2 is stored in the memory 38, and the counter 32 starts counting the clock signal C. Next, when the code detection sensor 4 reaches point q and outputs the code detection signal S, the rotation angle signal θ9 is stored in the memory 38, and the count value τ of the counter 32 is
At the same time, it is reset and starts counting the clock signal C anew. Then, the central processing unit 36 inputs the count value τ to the address corresponding to the rotation angle signal θ2. This operation is repeated until the rotation angle signal θ reaches the maximum value θ from Oo to X.

As explained above, the rotating arm 6 is connected to the servo controller 2.
6 rotates at a constant speed, the count value τ is the length of the trajectory 40 sequentially divided by the steel cords 12! The value is proportional to . Therefore, as understood from FIG. 2, the count value τ is the smallest value at the position where the rotating arm 6 and the steel cord 12 are parallel, that is, at the position where the angle θ and the cord angle α are complementary angles. The larger the difference between the rotation angle θ and the code angle α, the larger the value becomes.

Therefore, the code angle α can be determined by determining the rotation angle θ corresponding to the count value τ that gives the minimum value (FIG. 4).

That is, as shown in FIG. 4, the rotation angle θ:code detection interval curve is symmetrical about the code angle α. Immediately after the scanning of the rotary arm 6 is completed, the central processing unit 36 calculates the code angle α according to a predetermined procedure. In the method shown in Figure 4, the code angle α is theoretically the complementary angle of the rotation angle θ that corresponds to the minimum value of τ, but in reality, there are variations (unevenness) in the data around the minimum value of τ, so Using a value h larger than the minimum value, the code angle α is calculated from the average value of θ, I and θ,2 corresponding to the count value τ, and when the calculation is completed, the value is displayed on the display 42. Output. The above calculation may be performed for a plurality of count values τ, and the average value thereof may be determined.

Note that another means for detecting the rotation angle that provides the position at which the change in the steel detection interval is reversed includes finding the difference (differential value) between the previous detection interval and the current detection interval.

In order to further improve the detection accuracy, methods such as correcting the data by calculating the least squares solution assuming that the pitch and code angle of the actual steel cord are uniform are used to correct the variation in the data of the detected code interval. be able to.

In FIG. 1, the servo controller 26 and the clock 4
0 is described as a device independent from the central processing unit 36, however, a clock that operates the central processing unit 36 may be used as the clock 40, and the servo controller 26 may be controlled by the central processing unit 36. .

Even if the slope of the steel cord 12 in Fig. 2 is arranged in the opposite direction,
Although the code angle α can be detected in the same way, the detection accuracy is degraded.

〔Effect of the invention〕

As explained above, the steel cord angle detection method and apparatus of the present invention scan the surface of a steel-reinforced rubber sheet by moving the cord detection sensor on an arc, and determine the rotation angle and the distance between the steel cords. Since the cord angle is detected in a non-contact manner from a large amount of data obtained in - times of scanning, the following effects can be obtained.

Since the code angle is determined from a large amount of data obtained in one scan, it can be measured with high accuracy.

It can be measured non-destructively in a short time at any position on a 4° rubber sheet, and is extremely easy to operate.

As described above, the present invention can be applied not only to measurement in a test laboratory but also to process control at manufacturing processes and manufacturing sites for tires and the like.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the outline of the steel cord angle detection device of the present invention according to an embodiment, FIG. 2 is a diagram illustrating the principle of detecting the cord angle of FIG. 1, and FIG. FIG. 4 is a graph showing the relationship between the data obtained by the device of FIG. 1 and the code angle. DESCRIPTION OF SYMBOLS 1... Steel reinforced rubber sheet, 4... Cord detection sensor, 6... Rotating arm, 8... Rotation drive device (step motor), 10... Rotation angle sensor (rotary encoder), 12 ... Steel cord, 14 ... Cord angle detection section, 16 ... Stand, 18 ... Guide, 26
・・・Constant speed rotation control device (servo controller), 3
0...A/D converter, 32...Counter, 36.
...Central control unit, 38...Memory, 40...Clock, 42...Display device, a...Angle signal, C...
・Clock pulse signal, S... code detection signal, α・
...Code angle, τ...Clock pulse count value, θ...
·Angle of rotation.

Claims (3)

[Claims] (1) A code detection sensor that non-contactly detects a steel cord attached to a rotating arm that can scan the entire width of a steel-reinforced rubber sheet outputs a code when it passes a steel cord embedded in the rubber sheet. When the signal is output, the rotation angle from the scanning start position of the rotary arm is read, and the interval between the previous and current code detection signals is determined, and the rotation angle when the change trend of the code detection interval is reversed is determined. The desired steel cord angle detection method. (2) Provide a control device that rotates the rotary drive device at a constant speed,
2. The steel cord angle detection method according to claim 1, wherein the cord detection interval is detected based on the time width between the previous cord detection signal output and the current cord detection signal output. (3) A rotary arm equipped with a cord detection sensor that non-contactly detects the buried position of the steel cord is rotatably mounted, a steel reinforced rubber sheet is placed at a position where the cord detection sensor can scan the entire width, and the speed is constant. A rotational drive device and a rotation angle sensor consisting of a rotary encoder that detects the rotation angle from the scanning start position are attached to the rotary arm, and the output signal of the code detection sensor is applied to a conversion circuit that converts the output signal into a binary signal, and the conversion is performed. The output signal of the circuit is given to the code angle calculation means and the counter, and the code angle reading calculation means gives the angle signal outputted by the angle sensor to the storage means when the code detection signal is given, and the counter receives the code detection signal. When the next code signal is given, the clock signal starts counting, and when the next code signal is given, the counting result is given to the storage means, the counted value is reset and counting starts anew, and the rotation angle sensor receives the maximum rotation angle signal. A steel cord angle detecting device including a cord angle detecting section that outputs to a display means a rotation angle at which the change tendency of the sequentially inputted count signal is reversed from the angle signal and the count signal stored in the storage means.