JP2013186033A - Rotation angle detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation angle detector mainly used for rotation angle detection of a car steering, and capable of detecting a rotation angle with high accuracy over a wide range of ambient temperatures.SOLUTION: A control part 17 corrects a calculation angle calculated by detection signals from detection parts 15 and 16 using a predetermined angle correction value stored previously in accordance with variation in a rotation direction of a rotor 1 and a temperature detected by temperature detecting elements 15B and 16B and detects a rotation angle of the rotor 1. Thereby a rotation angle detector capable of detecting a rotation angle with a small error and high accuracy over a wide range of ambient temperatures can be realized.

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, with the advancement of functions of automobiles, an increasing number of vehicles detect the rotation angle of a steering wheel using a rotation angle detection device and perform various controls of the vehicle using this rotation angle.

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

  FIG. 4 is an exploded perspective view of a conventional rotation angle detection device. In FIG. 4, reference numeral 1 denotes a synthetic resin such as polyoxymethylene (hereinafter referred to as POM) having a spur gear portion 1A formed on the outer periphery of the side surface. A pair of engaging portions 1C that are engaged with a shaft of a steering (not shown) that is inserted through the inner periphery of the central cylindrical portion 1B.

  2 is a first detection body made of a synthetic resin such as POM having a spur gear portion 2A formed on the outer periphery of the side surface, and 3 is 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. In the second detection body made of synthetic resin such as POM, the spur gear portion 2A of the first detection body 2 meshes with the spur gear portion 1A of the rotating body 1, and the spur gear portion of the second detection body 3 3A meshes with the spur gear portion 2A of the first detector 2.

  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. Detection portions 5B and 6B made of a magnetic detection element or the like 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 is formed by the magnet 5A and the detection unit 5B facing each other, and the second detection means is formed by the magnet 6A and the detection unit 6B. A control unit 7 connected to the detection units 5B and 6B is formed by the components.

  Reference numeral 8 denotes a substantially box-shaped case made of synthetic resin such as polybutylene terephthalate (hereinafter referred to as PBT). A hollow of the lower surface of the rotating body 1 is formed inside the holding portion 8A protruding in a substantially ring shape of the case 8. The cylindrical portion 1B is rotatable about the central shaft hole (not shown) of the first detection body 2 on the shaft portion 8B and the central shaft hole (not shown) of the second detection body 3 on the shaft portion 8C. The rotation angle detection device 10 is configured by covering the case 8 with a cover (not shown).

  The rotation angle detection device 10 configured as described above is configured such that the control unit 7 is connected to a vehicle control unit (not shown) via a connector, a lead wire (not shown) or the like, and the rotating body. A steering shaft is inserted into the first engaging portion 1C and 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. For this reason, the magnets 5A and 6A mounted in the center also rotate, and the detection units 5B and 6B detect the changing magnetic force of the magnets 5A and 6A as detection signals. Since the detector 3 has a different number of teeth and different rotation speeds, the data waveforms of the detection units 5B and 6B are detection signals having different periods and shifted phases.

  Then, the control unit 7 performs a predetermined calculation based on the two different detection signals from the first detection body 2 and the second detection body 3 and the number of teeth of each spur gear portion, so that the rotating body 1, that is, the steering The rotation angle is detected and output to the control unit of the vehicle so that various controls of the vehicle are performed.

  The rotation angle detecting device 10 having such a configuration is provided with a certain gap between the hollow cylindrical portion 1B of the rotating body 1 inserted inside the holding portion 8A of the case 8 and the holding portion 8A. A certain amount of clearance is provided between the shaft hole on the lower surface of the one detection body 2 or the shaft hole on the lower surface of the second detection body 3 and the shaft portion 8B or 8C of the case 8, so The detection bodies 2 and 3 are rotatably held by the case 8.

  Further, the spur gear portion 1A on the side surface of the rotating body 1 and the spur gear portion 2A on the side surface of the first detector 2, the spur gear portion 2A on the side surface of the first detector 2 and the spur gear portion 3A on the side surface of the second detector 3. Are in mesh with each other with backlash, that is, play, between the meshing spur gears.

  Therefore, when the rotation of the rotating body 1 that rotates in conjunction with the steering changes, for example, from the clockwise rotation to the counterclockwise rotation and the rotation direction, the clearance between the rotating body 1 and the holding portion 8A and the first And the gaps between the second detection bodies 2 and 3 and the shaft portions 8B and 8C and the backlash between the rotating body 1 and the first detection body 2 or between the first detection body 2 and the second detection body 3. Rotation deviation occurs between the rotating body 1 and the first and second detecting bodies 2 and 3, and the first detecting body 2 and the second detecting body with respect to the actual rotation angle of the rotating body 1. Thus, an error is likely to occur in the rotation angle calculated by the control unit 7 based on the detection signal from 3.

  Furthermore, the synthetic resin material of the rotating body 1 and the first and second detection bodies 2 and 3 and the case 8 in which these are rotated and held are formed of different materials, so that the ambient temperature is high, for example, + 85 ° C. When used in a low temperature range of -40 ° C., the above-described rotating body 1 and the first and the second are different depending on the degree of expansion and contraction of the shape dimensions due to the temperature increase / decrease of each material, so-called linear expansion coefficient. The magnitude of the rotational deviation between the rotation of the second detectors 2 and 3 tends to be small at high temperatures and large at low temperatures.

  As a prior art document related to the invention of this application, for example, Patent Document 1 is known.

JP 2010-71661 A

  However, in the conventional rotation angle detection device 10 described above, the rotation body 1, the first and second detection bodies 2, 3, the gaps of the rotation holding portion between the case 8, the rotation body 1, the first and second rotations, and the like. Rotation deviation is likely to occur between the rotating body 1 and the first and second detecting bodies 2 and 3 due to backlash accompanying the meshing of the spur gear portions 1A, 2A and 3A between the detecting bodies 2 and 3 Met.

  In addition, such rotational deviation tends to increase or decrease depending on the ambient temperature used. For example, the rotational deviation is small at high temperatures and large at low temperatures, and is detected by the first detection means and the second detection means. There has been a problem that a slightly large error may occur in the detected rotation angle.

  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 detecting a rotation angle with high accuracy in a wide range of ambient temperatures.

  In order to achieve the above object, according to the present invention, a temperature detection unit is provided in the rotation angle detection device, and the control unit stores a predetermined value stored in advance according to the change in the rotation direction of the rotating body and the temperature detected by the temperature detection unit. Using this angle correction value, the angle calculated by the detection signal from the detection unit is corrected, and the rotation angle detection device is configured to detect the rotation angle of the rotating body.

  According to the present invention, the control unit generates a predetermined angle correction value based on the correlation between the temperature stored in advance and the angle error according to the detected ambient temperature and the change in the rotation direction of the rotating body, based on the detection signal from the detection unit. By detecting the rotation angle of the rotating body by adding or subtracting it to the calculated angle, the error with the actual rotation angle of the rotating body is reduced, and the rotation angle enables highly accurate rotation angle detection over a wide range of ambient temperatures. An advantageous effect that a detection device can be realized is obtained.

The block diagram of the rotation angle detection apparatus by one embodiment of this invention Exploded perspective view The figure which shows the same temperature-angle correction value correlation data An exploded perspective view of a conventional rotation angle detection device

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  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 block diagram of a rotation angle detection device according to an embodiment of the present invention, FIG. 2 is an exploded perspective view thereof, and 1 is a composite of POM or the like in which a spur gear portion 1A is formed on the outer periphery of a side surface. A pair of engaging portions 1C that are engaged with a shaft of a steering (not shown) that is inserted through the inner periphery of the central cylindrical portion 1B are formed of a resin-made rotating body.

  2 is a first detection body made of a synthetic resin such as POM having a spur gear portion 2A formed on the outer periphery of the side surface, and 3 is 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. In the second detection body made of synthetic resin such as POM, the spur gear portion 2A of the first detection body 2 meshes with the spur gear portion 1A of the rotating body 1, and the spur gear portion of the second detection body 3 3A meshes with the spur gear portion 2A of the first detector 2.

  Reference numeral 4 denotes a wiring board such as paper phenol or glass epoxy arranged 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. In addition, an AMR (anisotropic magnetoresistive) element is provided on the opposing surface of the magnet 5A mounted at the center of the first detector 2 and the magnet 6A mounted at the center of the second detector 3. Detection units 15 and 16 each having a temperature detection element 15B, 16B such as a semiconductor temperature sensor as a temperature detection unit and a temperature detection unit are integrally formed.

  The detection units 15 and 16 detect the magnetic force changing with the rotation of the opposing magnets 5A and 6A as a voltage by the magnetic detection elements 15A and 16A and output a detection signal. At this time, the temperature detection elements 15B and 16B Based on the detected temperature, the detected voltage is corrected.

  That is, the voltage detected by the magnetic detection elements 15A and 16A with the same magnetic force is slightly increased at high temperatures and slightly increased at low temperatures, so that the detection voltages of the magnetic detection elements 15A and 16A that tend to increase or decrease depending on the ambient temperature are corrected to increase the voltage. A detection signal that is less affected by temperature from a low temperature to a low temperature and has a small detection error is output.

  The first detection means is formed by the magnet 5A and the detection unit 15 opposed to each other, and the second detection means is formed by the magnet 6A and the detection unit 16, respectively. A control unit 17 connected to the detection units 15 and 16 is formed by electronic components such as a storage unit 17A such as a memory.

  Further, 8 is a case made of a synthetic resin such as PBT, which is substantially box-shaped, and the hollow cylindrical portion 1B on the lower surface of the rotating body 1 is formed inside the holding portion 8A protruding in a substantially ring shape of the case 8, and the shaft portion 8B The central shaft hole (not shown) of one detection body 2 is rotatably held by the shaft portion 8C with the central shaft hole (not shown) of the second detection body 3, and above the case 8. The rotation angle detector 20 is configured by covering a cover (not shown).

  In addition, such a rotation angle detection device 20 includes a clearance between the rotating body 1 and the holding portion 8A of the case 8, and a clearance between the first and second detection bodies 2 and 3 and the shaft portions 8B and 8C of the case 8. And the spur gear portion 1A of the rotating body 1 and the spur gear portion 2A of the first detecting body 2 and the backlash of the spur gear section 2A and the spur gear portion 3A of the second detecting body 3, for example, the rotating body 1 Is shifted to the rotation between the rotating body 1 and the first detecting body 2 and the second detecting body 3 engaged with the rotating body 1 when the rotation is changed from the clockwise rotation to the reverse counterclockwise rotation. May occur.

  Therefore, as will be described later, the angle calculated by the control unit 17 via the first detection means and the second detection means as the first detection body 2 and the second detection body 3 rotate, and the rotation body 1 An error also occurs with respect to the actual rotation angle.

  Further, the rotational deviation between the rotating body 1 and the first and second detection bodies 2 and 3 is that the material of the rotating body 1 and the first and second detection bodies 2 and 3 is POM and the material of the case 8. In the case of PBT, the temperature tends to increase or decrease depending on the temperature so that it is small at high temperatures and large at low temperatures.

  Therefore, as shown in the temperature-angle correction value correlation data in FIG. 3, the controller 17 first uses a plurality of rotation angle detectors 20 to change the rotation direction at a plurality of ambient temperatures from low to high. A standard angle correction value A is stored in which the difference between the rotation angle substantially measured of the rotating body 1 and the rotation angle calculated by the rotation angle detector 20 is substantially linear correlation data.

  Further, in the finished product inspection in the manufacturing process of the rotation angle detection device 20, in order to correct the deviation from the angle correction value A of the individual rotation angle detection device 20 due to the finished shape and variation of the parts, for example, rotation at a temperature of 25 ° C. When the difference between the substantial rotation angle of the body 1 and the rotation angle calculated by the individual rotation angle detector 20 is 1.3 degrees, the standard angle correction value A 1.1 previously stored by the control unit 17 is 1.1. Since the angle is 0.2 degrees larger than the angle, 0.2 degrees is added to the entire standard angle correction value A, and the added individual angle correction value B is added to the control unit 17 of the individual rotation angle detection device 20 as an angle. It is stored as a correction value.

  In the rotation angle detection device 20 configured as described above, the control unit 17 is connected to the control unit of the vehicle via a connector, a lead wire (not shown) or the like, and the engaging unit of the rotating body 1 A steering shaft is inserted into 1C and mounted on 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 detection elements 15A and 16A detect the changing magnetic force of the magnets 5A and 6A as a detection signal, and the temperature detection elements 15B and 16B are the surroundings. These signals are output to the control unit 17 by detecting the temperature.

  Since the first detection body 2 and the second detection body 3 have different numbers of teeth and different rotation speeds, the data waveforms of the magnetic detection elements 15A and 16A are detection signals with different periods and shifted phases.

  The control unit 17 calculates the calculation angle from the two different detection signals from the detection units 15 and 16 and the number of teeth of each spur gear unit, and the control unit 17 detects the rotation angle from the detection signal. A change is detected, and a predetermined angle correction value stored in advance in the storage unit 17A is added to or subtracted from the calculated angle according to the change in the rotation direction and the input temperature, and the rotation angle of the rotating body 1, that is, the steering is detected. This is output to the control unit of the vehicle, and various controls of the vehicle are performed.

  Here, a rotation angle detection example will be described with reference to FIG. 3. For example, when the rotating body 1 is rotated 30 degrees clockwise and the rotating body 1 is further rotated 20 degrees clockwise. The control unit 17 determines that the rotation is in the same direction, and does not perform angle correction on the angle of 50 degrees calculated from the detection signals from the detection units 15 and 16, but detects the calculated angle of 50 degrees as the rotation angle.

  Further, for example, when the rotating body 1 is rotated 30 degrees in the clockwise direction and the rotating body 1 is rotated 20 degrees in the counterclockwise direction, the control unit 17 counteracts the rotating direction from the clockwise direction stored in advance. It is determined that the temperature has changed in the clockwise direction, and the temperatures from the detection units 15 and 16 are averaged to detect, for example, 25 ° C.

  Further, the control unit 17 calculates based on the detection signal including the rotational deviation from the detection units 15 and 16 and detects the calculation angle as 11.3 degrees, but the individual shown in FIG. 3 stored in the storage unit 17A. An angle correction value of 1.3 degrees at a temperature of 25 ° C. is subtracted from the calculated angle of 11.3 degrees from the angle correction value B of 10 degrees, and the rotation angle is set to 10 degrees. Detect the rotation angle.

  At this time, when the ambient temperature is 0 ° C. in the same rotation state, for example, the control unit 17 detects the calculation angle as 11.6 degrees from the detection signal including the rotational deviation. An angle correction value of 1.6 degrees at a temperature of 0 ° C. is subtracted from the angle correction value B from the calculation angle of 11.6 degrees to detect the rotation angle as 10 degrees.

  That is, when the detection signals from the detection units 15 and 16 are input to the control unit 17 and the stored previous rotation direction is compared with the rotation direction based on the detection signal input this time, Detects the calculated angle as the rotation angle without calculating the angle based on the detection signal and correcting the angle, and when the stored previous rotation direction is different from the current rotation direction, the detection unit 15, The temperature data is detected from the 16 temperature detection elements 15B and 16B, and the calculation angle calculated based on the detection signal is changed in the rotation direction, that is, from the clockwise direction to the counterclockwise direction, or from the counterclockwise direction to the clockwise direction. In accordance with the change to the above, by adding or subtracting a predetermined angle correction value based on the stored temperature to the calculation angle, the high-precision rotating body 1 with less error due to rotational deviation at a wide range of ambient temperatures can be obtained. So that the rotation angle can detect.

  Thus, according to the present embodiment, the control unit 17 uses a predetermined angle correction value stored in advance according to the change in the rotation direction of the rotating body 1 and the temperature detected by the temperature detection elements 15B and 16B. By correcting the calculation angle calculated by the detection signals from the detection units 15 and 16 and detecting the rotation angle of the rotating body 1, the rotating body 1 and the first and second detecting bodies 2 and 3 according to the ambient temperature are detected. Since the angle correction value corresponding to the angle error due to the rotational deviation between the two is adjusted to the calculated angle, the rotation angle can be detected with high accuracy and with little error at a wide range of ambient temperatures with respect to the actual rotation angle of the rotating body 1. A rotation angle detection device can be realized.

  Further, by using the detection units 15 and 16 in which the magnetic detection elements 15A and 16A and the temperature detection elements 15B and 16B are integrally formed, based on the temperatures detected by the temperature detection elements 15B and 16B, the magnetic detection elements 15A and 15A, The detection signal by 16A can be corrected, and the detected temperatures of the two temperature detection elements 15B and 16B are averaged and this temperature is regarded as the ambient temperature, so that the detected temperature can be compared with the case where the temperature is detected by only one temperature detection element. The bias is reduced, and the rotation angle can be detected with higher accuracy.

  In the above description, the temperature detection elements 15B and 16B as temperature detection parts have been described as integrally formed with the magnetic detection elements 15A and 16A in the detection parts 15 and 16, respectively, but the detection accuracy is somewhat inferior, The present invention can be implemented even if the temperature detection unit is integrally formed in the control unit, or the temperature detection unit is provided separately and connected to the control unit.

  In the above description, the magnets 5A and 6A are attached to the first detection body 2 interlocked with the rotating body 1 and the second detection body 3 interlocked with the first detection body 2, respectively. Although the configuration in which the control unit 17 detects the rotation angle of the rotating body 1 based on the detection signals from the detecting units 15 and 16 facing 6A has been described, the first detecting body 2 and the second detection are detected in the rotating body 1. It is good also as a structure which makes the control part detect the rotation angle of the rotary body 1 from the rotation of the 1st and 2nd detection bodies 2 and 3 similarly to the above, making the body 3 mesh and interlock | cooperate.

  Further, as the configuration of only the first detecting means composed of the first detecting body 2 interlocked with the rotating body 1, the magnet 5 </ b> A mounted on the rotating body 1, and the detecting section 15, the rotation angle is stored in the control section as needed to rotate. The present invention can be implemented in various rotation angle detection devices such as one that detects the rotation angle of the body 1.

  The rotation angle detection device of the present invention has an advantageous effect that a rotation angle detection device capable of detecting a rotation angle with high accuracy in a wide range of ambient temperatures can be obtained. Useful for detection.

DESCRIPTION OF SYMBOLS 1 Rotating body 1A, 2A, 3A Spur gear part 1B Central cylinder part 1C Engagement part 2 1st detection body 3 2nd detection body 4 Wiring board 5A, 6A Magnet 8 Case 8A Holding part 8B, 8C Shaft part 15, DESCRIPTION OF SYMBOLS 16 Detection part 15A, 16A Magnetic detection element 15B, 16B Temperature detection element 17 Control part 17A Storage part 20 Rotation angle detection apparatus

Claims (2)

A rotating body that rotates in conjunction with the steering, a detection body that rotates with the rotation of the magnet mounted in the center, a detector that is disposed opposite to the magnet and detects the magnetism of the magnet, The control unit includes a control unit that detects a rotation angle of the rotating body based on a detection signal from the detection unit. A temperature detection unit is provided, and the control unit detects a change in the rotation direction of the rotating body and a temperature detected by the temperature detection unit. Accordingly, a rotation angle detection device that corrects the calculation angle calculated by the detection signal from the detection unit using a predetermined angle correction value stored in advance and detects the rotation angle of the rotating body. The rotation angle detection device according to claim 1, wherein the temperature detection unit is integrally formed in the detection unit.

Images