JP5597914B2 - Rotation angle detector - Google Patents

Description

  The present invention relates to a rotation angle detection device mainly used for detecting a rotation angle of a steering wheel of an automobile.

  In recent years, as the functions of automobiles have advanced, the number of steering angle detection devices that use various rotation angle detection devices to control various types of vehicles using this has increased.

  Such a conventional rotation angle detection device will be described with reference to FIG.

  FIG. 3 is a perspective view of a conventional rotation angle detection device. In FIG. 3, reference numeral 1 denotes a rotating body having a spur gear portion 1A formed on the outer periphery of a side surface, and a steering shaft (not shown) inserted through a central portion. An engaging portion 1B that engages with is provided.

  2 is a first detector having a spur gear portion 2A formed on the outer periphery of the side surface, and 3 is a second detector having a spur gear portion 3A having a different number of teeth from the spur gear portion 2A on the outer periphery of the side surface. The spur gear portion 2A of the first detection body 2 and the spur gear portion 3A of the second detection body 3 are engaged with the spur gear portion 1A of the rotating body 1, respectively.

  Reference numeral 4 denotes a wiring board disposed substantially in parallel above the first and second detection bodies 2 and 3, and a plurality of wiring patterns (not shown) are formed on the upper and lower surfaces, and the first detection is performed. Magnetic detection elements 5B and 6B are mounted on the opposing surfaces of the magnet 5A mounted at the center of the body 2 and the magnet 6A mounted at the center of the second detection body 3, respectively.

  The first detection means 5 is formed by the magnet 5A and the magnetic detection element 5B opposed to each other, and the second detection means 6 is formed by the magnet 6A and the magnetic detection element 6B. The control means 7 connected to the magnetic detection elements 5B and 6B is formed by electronic components such as a microcomputer.

  Further, the rotating body 1, the first detector 2, the second detector 3, the wiring board 4, etc. are covered with an insulating resin case, a cover (not shown), etc. to constitute a rotation angle detector. Has been.

  The rotation angle detecting device configured as described above is connected to an electronic circuit (not shown) of the automobile via the control means 7, a connector, a lead wire (not shown) and the like, and the rotating body 1 A steering shaft is inserted into the engaging portion 1B and is attached to the automobile.

  In the above configuration, when the steering is rotated, the rotating body 1 is rotated, and the first detecting body 2 and the second detecting body 3 are rotated in conjunction with the rotation. Therefore, the magnet 5A mounted at the center thereof is provided. , 6A also rotates, and the magnetic detecting elements 5B, 6B detect the magnetic force changing by the magnets 5A, 6A, and a sine wave, cosine wave, or substantially sawtooth detection signal that repeatedly increases and decreases is input to the control means 7. Is done.

  At this time, since the first detector 2 and the second detector 3 have different numbers of teeth and different rotation speeds, the data waveforms from the magnetic detection elements 5B and 6B have different shapes and detection signals having a phase difference. It becomes.

  Then, from the two different detection signals from the first detection body 2 and the second detection body 3 and the number of teeth, the control means 7 performs a predetermined calculation to determine the rotation angle of the rotating body 1, that is, the steering. This is detected and output to an electronic circuit of the automobile body, and various controls of the vehicle such as a power steering device and a brake are performed.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
JP 2005-3625 A

  However, in the conventional rotation angle detection device, when the spur gear portions 2A and 3A of the first detection body 2 and the second detection body 3 are damaged or consumed, or the error of the magnetic detection elements 5B and 6B. Since it is difficult to detect these problems when the size of the device becomes large, a separate detection body or detection element for such error detection is required, and the configuration becomes complicated and expensive. was there.

  The present invention solves such a conventional problem, and an object of the present invention is to provide a rotation angle detection device capable of reliably detecting a rotation angle with a simple configuration.

  In order to achieve the above object, the present invention has the following configuration.

The invention according to claim 1 of the present invention includes a rotating body that rotates in conjunction with a steering wheel, first and second detectors that rotate in conjunction with the rotating body and have different rotation ratios, and the first detector. And first and second detection means for detecting the rotation of the second detection body, and control means for detecting the rotation angle of the rotation body based on the detection signals from the first and second detection means, The control means detects the approximate rotation angle of the rotating body from the detection signals from the first and second detection means, and the detailed rotation of the rotating body from the detection signal from the first or second detection means. In addition to detecting the angle, the first and second detection bodies are accumulated from the number of rotations and the angle of the first and second detection bodies by detection signals from the first and second detection means. Rotation angle is detected and each rotation This is a rotation angle detection device that calculates the detailed rotation angle of each of the above rotating bodies from the degree and compares them, and when each spur gear is damaged or worn, or when an error occurs in each detection means For example, these defects can be detected by the difference in the rotation angle of the rotating body calculated from the rotation angles of the first and second detection bodies, so that the rotation angle can be reliably detected with a simple configuration. It is possible to obtain a rotation angle detection device capable of performing

  According to a second aspect of the present invention, in the first aspect of the invention, the notification means is provided, and the notification means is operated according to the rotation angle detected by the control means. In the case where a malfunction occurs, it is possible to easily notify this by a notification means such as a warning light or a buzzer.

  As described above, according to the present invention, it is possible to obtain an advantageous effect that it is possible to realize a rotation angle detection device capable of reliably detecting a rotation angle with a simple configuration.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  In addition, the same code | symbol is attached | subjected to the part of the structure same as the structure demonstrated in the term of background art, and detailed description is simplified.

(Embodiment)
FIG. 1 is a perspective view of a rotation angle detection device according to an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a rotating body made of insulating resin or metal, and a spur gear portion 1A is formed on the outer periphery of the side surface. The central portion is provided with an engaging portion 1B that engages with a shaft of a steering (not shown) to be inserted.

  2 is a first detection body made of insulating resin or metal, 3 is also a second detection body, and the spur gear portion 2A on the outer periphery of the first detection body 2 is engaged with the spur gear portion 1A of the rotating body 1. In addition, a spur gear portion 3A having a different number of teeth from the spur gear portion 2A on the outer periphery of the side surface of the second detector 3 meshes with the spur gear portion 2A of the first detector 2.

  In addition, the diameter and the number of teeth of these gears are the largest in the rotating body 1, and are decreasing in the order of the first detecting body 2 and the second detecting body 3. For example, the number of teeth of the rotating body 1 is 48, The number of teeth of the first detection body 2 is 32, and the number of teeth of the second detection body 3 is 28.

  Reference numeral 4 denotes a wiring board disposed substantially in parallel above the first and second detection bodies 2 and 3, and a plurality of wiring patterns (not shown) are formed on the upper and lower surfaces, and the first detection is performed. Magnetic detection of an AMR (anisotropic magnetoresistive) element or the like is provided on the opposing surface of the magnet 5A attached to the center of the body 2 by insert molding or the like and the magnet 6A attached to the center of the second detector 3. Elements 5B and 6B are respectively mounted.

  The first detection means 5 is formed by the magnet 5A and the magnetic detection element 5B opposed to each other, and the second detection means 6 is formed by the magnet 6A and the magnetic detection element 6B. The control means 10 connected to the magnetic detection elements 5B and 6B is formed by electronic parts such as a microcomputer.

  Further, 11 is an informing means such as a light emitting diode, a buzzer, a liquid crystal display element, etc. The informing means 11 is connected to the control means 10, and the rotating body 1, the first detecting body 2 and the second detecting body 3 are connected. The rotation angle detector is configured by covering the wiring board 4 and the control means 10 with a case or cover (not shown) made of an insulating resin.

  In the rotation angle detecting device configured as described above, the control unit 10 is connected to an electronic circuit (not shown) of the automobile via a connector, a lead wire (not shown) or the like, and the rotating body 1 A steering shaft is inserted into the engaging portion 1B and is attached to the automobile.

  In the above configuration, when the steering is rotated, the rotating body 1 is rotated, and the first detecting body 2 is rotated in conjunction with the rotating body 1 and the second detecting body 3 is rotated in conjunction with the first detecting body 2. Therefore, the magnets 5A and 6A mounted in the center also rotate, and the magnetic detecting elements 5B and 6B detect the changing magnetic force of the magnets 5A and 6A, and sine waves and cosine waves that repeat increase and decrease, or approximately A sawtooth detection signal is input to the control means 10.

  At this time, since the first detection body 2 and the second detection body 3 have different numbers of teeth and different rotation speeds, the detection signal L of the first detection body 2 shown in the waveform diagram of FIG. The detection signal M of the second detector 3 shown in FIG. 2 (b) is a data waveform having a phase difference with different tooth number ratios k2 and k3, which are inclination angles of a substantially sawtooth waveform.

  Then, from these detection signals, the control means 10 first determines, for example, the second rotation of the detection signal M of the second detection body 3 from the angle θ2 of the second detection body L of the detection signal L of the first detection body 2. By subtracting the angle θ3, a gradually increasing linear phase difference signal N as shown in FIG. 2C is calculated, and the approximate rotation angle of the rotating body 1 is detected from this angle θ2-θ3.

  Thereafter, the control means 10 detects the detailed rotation angle θ1 of the rotating body 1 from the angle θ2 of the detection signal L or the angle θ3 of the detection signal M and the number of teeth of each spur gear portion, and this is the automobile body. Are output to the electronic circuit, and various controls of the vehicle such as a power steering device and a brake are performed.

  Further, at this time, as shown in FIG. 2 (d), the control means 10 calculates the first detection body 2 from the rotation number and angle θ2, and the second detection body 3 rotation number and angle θ3. The accumulated rotation angle θA of the detection body 2 and the accumulated rotation angle θB of the second detection body 3 are detected, and the detailed rotation angle θ1 of the rotation body 1 is calculated from the rotation angles θA and θB.

  Then, the control means 10 compares the detailed rotation angle θ1 of the rotating body 1 calculated from the rotation angles θA and θB of the first detection body 2 and the second detection body 3, respectively, and these are compared with a predetermined value or more. When there is a difference, for example, a difference of 5 degrees or more, the notifying means 11 is operated to blink the light emitting diode or buzzer, or display an error display on the liquid crystal display element, etc. Output to the circuit.

  That is, the control means 10 detects the outline and detailed rotation angle θ1 of the rotating body 1 from the detection signal L of the first detecting body 2 and the detection signal M of the second detecting body 3, and separately from this. The detailed rotation angle θ1 of the rotating body 1 is calculated from the rotation angles θA and θB of the first detection body 2 and the second detection body 3, and these are compared.

  That is, when the spur gear portions 2A and 3A of the first detection body 2 and the second detection body 3 are damaged or consumed, or when errors occur in the magnetic detection elements 5B and 6B, the first detection body 2 is used. Because the control means 10 can detect these defects by the difference of the detailed rotation angle θ1 of the rotating body 1 calculated from the rotation angles θA and θB of the second detecting body 3 and more than a predetermined value. The rotation angle can be reliably detected without separately providing a detection body, a detection element, or the like for error detection.

  The angle of the first detection body 2 or the second detection body 3 is multiplied by the gear ratio with the rotating body 1 to obtain a predetermined rotational angle difference of the rotating body 1 rotating at a lower speed than each detecting body. There is a method of calculating a constant and detecting an error in the rotation angle of the rotating body 1 by changing the constant, but as described above, the rotation of the first detecting body 2 and the second detecting body 3 is compared with such a method. By calculating the detailed rotation angle θ1 of the rotating body 1 from the angles θA and θB and comparing them, it is possible to detect errors with higher accuracy and higher resolution.

  That is, instead of detecting an error by the rotation angle of the rotating body 1 that rotates only the same angle as the rotation of the steering wheel, the first detecting body 2 and the second detecting body 3 having a larger amount of rotation than the rotating body 1 are detected. By detecting an error in the rotation angle of the rotating body 1 from the difference in rotation angle, the resolution is improved and the error can be detected with higher accuracy.

  In the above description, the control means 10 first detects the approximate rotation angle of the rotating body 1 from the detection signal L of the first detection body 2 and the detection signal M of the second detection body 3, and thereafter Although the configuration for detecting the detailed rotation angle has been described, the rotation angle is directly detected by the two detection signals L and M having different phases and different phases from the first detection body 2 and the second detection body 3. It is good also as a structure.

  Thus, according to the present embodiment, the control means 10 calculates the rotation angles of the rotating body 1 from the rotation angles of the first detection body 2 and the second detection body 3, and compares them. Thus, when the spur gears are damaged or worn, or when errors occur in the detection means, the rotation of the rotating body 1 calculated from the rotation angles of the first detection body 2 and the second detection body 3 respectively. Since these problems can be detected by the difference in angle, a rotation angle detection device capable of reliably detecting the rotation angle with a simple configuration can be obtained.

  And when notifying means 11 is provided and a malfunction occurs in each detecting body or detecting means by operating this notifying means 11 according to the rotation angle detected by the control means 10, a warning light, a buzzer, etc. This can be easily notified.

  In the above description, the rotation angle detection device having the configuration in which the first detection body 2 meshes with the rotating body 1 and the second detection body 3 meshes with the first detection body 2 has been described. As described in the technical section, the present invention can be implemented even with a configuration in which both the first detection body 2 and the second detection body 3 are engaged with the rotating body 1.

  Moreover, in the above description, the spur gear part was each formed in the outer periphery of the rotary body 1, the 1st detection body 2, and the 2nd detection body 3, and these were meshed | engaged and the structure which rotates mutually interlock | cooperated was demonstrated. However, in addition to spur gears, bevel gears and other shapes are used, or instead of gears, irregularities and high friction parts that can transmit rotation are provided on the outer periphery of the rotating body and each detecting body. It is good also as a structure which forms and rotates in conjunction with this.

  The rotation angle detection device according to the present invention has a simple configuration and can reliably detect the rotation angle, and is mainly useful for detecting the rotation angle of the steering of an automobile.

The perspective view of the rotation angle detection apparatus by one embodiment of this invention Waveform diagram A perspective view of a conventional rotation angle detection device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating body 1A, 2A, 3A Spur gear part 1B Engagement part 2 First detection body 3 Second detection body 4 Wiring board 5 First detection means 5A, 6A Magnet 5B, 6B Magnetic detection element 6 Second Detection means 10 Control means 11 Notification means

Claims (2)

A rotating body that rotates in conjunction with the steering, a first and a second detecting body that rotate in conjunction with the rotating body and have different rotation ratios , and a first that detects the rotation of the first and second detecting bodies. The first and second detection means and control means for detecting the rotation angle of the rotating body based on the detection signals from the first and second detection means, the control means being the first and second detection means. A rotation angle of the rotating body is detected based on a detection signal from the first and second detection means, and a detailed rotation angle of the rotating body is detected based on a detection signal from the first or second detection means. The accumulated rotation angle of the first and second detection bodies is detected from the number of rotations and the angle of the first and second detection bodies based on the detection signal from the second detection means, and each of these rotations is detected. Detailed rotation of the rotating body from the angle Degrees respectively calculated, the rotation angle detecting device comparing these. The rotation angle detection apparatus according to claim 1, wherein the notification means is provided and the notification means is operated according to the rotation angle detected by the control means.

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