JP2001033205A - Rotation angle sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation angle sensor capable of measuring the rotation angle of a measurement target object rotating not less than 360 degrees, and of measuring the rotation angle of the measurement target object during power input even when the rotation angle thereof during power disconnection is unstored in a memory and the like. SOLUTION: When a lever member 6 passes through a neutral line Q, a switch member 12a is switched into an on or off state, so that it is possible to determine whether the lever member 6 is rotating in a clockwise or counterclockwise direction relative to the neutral line Q. Accordingly, even when a measurement target object rotates through not less than 360 degrees, the rotation angle thereof can be measured if it is smaller than 720 degrees.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for measuring 3 objects.
The present invention relates to a rotation angle sensor that can measure the rotation angle of a measurement target even when the object rotates 60 degrees or more (meaning that it makes a circular motion in a clockwise direction and a counterclockwise direction).

[0002]

2. Description of the Related Art A rotation angle sensor measures the rotation angle of an object to be measured (for example, a pinion gear of an actuator), and a potentiometer or an encoder circuit is mainly used as the rotation angle sensor. FIG. 6 shows an example of such a potentiometer. As shown in FIG. 6, the potentiometer 90 mainly
The first resistor 91, the second resistor 92, the first brush member 93, the second brush member 94, the lever member 95, the first signal line 96, the second signal line 97, and the first voltage Signal line 9
8 and a second voltage signal line 99.

According to the potentiometer 90, when the object to be measured rotates, the lever member 95 is rotated about the center Z in accordance with the rotation. Lever member 9
5 is rotated in the arrow X direction (clockwise direction in FIG. 6), the first brush member 93 and the second brush member 94 attached to the lever member 95 also move to the lever member 9.
5 is rotated in the same direction (that is, the arrow X direction). When the first brush member 93 and the second brush member 94 are rotated, a contact position (hereinafter, referred to as a “first contact position”) Y1 between the first resistor 91 and the first brush member 93, and a second resistor. The contact position (hereinafter, referred to as “second contact position”) Y2 between the body 92 and the second brush member 94 is changed. Here, the first resistor 91 and the second resistor 92
, A voltage is applied by a first voltage signal line 98 and a second voltage signal line 99, the first resistor 91 and the first signal line 96 are short-circuited by the first brush member 93, and the second brush member The second resistor 92 and the second signal line 97 are short-circuited by 94. For this reason, when the first contact position Y1 is changed, the potential at the terminal A changes, and similarly, the second contact position Y1 changes.
When the contact position Y2 is changed, the potential at the terminal B also changes. The potential at the terminal A and the potential at the terminal B are output signals of the potentiometer 90, and the rotation signals of the measurement object can be measured by the output signals.

[0004]

However, when the lever member 95 is located at a position indicated by a dotted line P, for example, the lever member 95 is moved in a direction indicated by an arrow X (clockwise direction) with respect to a position indicated by a neutral line (a kind of reference position) Q. ) Or the counterclockwise arrow X (counterclockwise) cannot be discriminated. In other words, there has been a problem that when the measurement object rotates 360 degrees or more, the rotation angle of the measurement object cannot be measured.

As described above, the rotation angle of the object to be measured may be measured by the encoder circuit. The encoder circuit normally outputs a pulse signal corresponding to the rotation of the measurement target when the measurement target rotates. That is, in the encoder circuit, the rotation angle of the measurement target is measured based on how many pulses the measurement target has rotated from the reference position. Therefore, when the power of the encoder circuit is turned off and then turned on again, the rotation angle of the measurement object at the time of turning on the power must be stored in a storage device or the like when the power is turned off. There was a problem that the angle could not be measured.

Accordingly, the present invention was devised,
It is possible to measure the rotation angle of the measurement object that rotates 360 degrees or more. Further, even if the rotation angle of the measurement object when the power is turned off is not stored in a storage device or the like, the measurement object can be measured when the power is turned on. It is an object of the present invention to provide a rotation angle sensor that can measure a rotation angle of an object.

[0007]

In order to achieve this object, a rotation angle sensor according to claim 1 comprises a plurality of resistors formed in an arc shape and arranged concentrically, and a plurality of resistors arranged on the resistors. It is determined whether the brush member that is slid in accordance with the rotation of the object to be measured, and whether the contact position between the resistor and the brush member changes clockwise or counterclockwise with respect to the reference position. And a determination device.

According to the rotation angle sensor of the first aspect, when the object to be measured rotates, the brush member slides on the resistor according to the rotation of the object to be measured. When the brush member is slid on the resistor in this manner, the discriminating device determines whether the contact position of the resistor and the brush member changes clockwise or counterclockwise with respect to the reference position. Is determined. For this reason, even when the measurement target rotates 360 degrees or more, the rotation angle of the measurement target can be measured. Further, since the brush member is configured to slide on the resistor according to the rotation of the measurement target, the rotation angle of the measurement target when the power is turned off is stored in a storage device or the like. Even without this, it is possible to measure the rotation angle of the measurement target when the power is turned on.

According to a second aspect of the present invention, there is provided a rotation angle sensor.
In the rotation angle sensor described above, a gap between one resistor and a gap between other resistors are arranged at positions where they do not overlap with each other.

According to a third aspect of the present invention, there is provided a rotation angle sensor.
Or in the rotation angle sensor according to 2, wherein the discriminating device is:
When the contact position between the resistor and the brush member passes through the reference position, the switch member switches to an on state or an off state.

According to a fourth aspect of the present invention, there is provided a rotation angle sensor according to the first aspect.
3. The rotation angle sensor according to any one of 1 to 3, wherein the switch member is mechanically switched to an on state or an off state.

According to a fifth aspect of the present invention, there is provided a rotation angle sensor according to the fourth aspect.
The rotation angle sensor described above includes a holding member that holds the switch member at a position where the switch member is switched to an on state or an off state.

According to a sixth aspect of the present invention, there is provided a rotation angle sensor.
In the rotation angle sensor according to any one of (1) to (5), the direction of increase and decrease of the potential at the contact position of one resistor and the brush member and the direction of increase and decrease of the potential at the contact position of another resistor and the brush member match. A connected signal line, a potential difference adding circuit for adding a potential difference between the potential at the one contact position and a potential at another contact position to the potential at the one contact position, and a potential difference added by the potential difference adding circuit. Potential at one contact position,
Or a selection device for selecting a potential at the another contact position.

According to the rotation angle sensor according to the sixth aspect, the rotation angle sensor operates in the same manner as the rotation angle sensor according to any one of the first to fifth aspects. The wires are connected so that the direction of increase or decrease of the potential at the position (one contact position) and the direction of increase or decrease of the potential at the contact position (another contact position) of another resistor and the brush member coincide with each other. Selects a potential at one contact position to which a potential difference is added or a potential at another contact position.

According to a seventh aspect of the present invention, there is provided a rotation angle sensor according to the sixth aspect.
In the rotation angle sensor described above, the potential difference adding circuit may be connected to one of the ground side of one resistor or the power supply side of another resistor, or the ground side of one resistor and the power supply side of another resistor. And a second resistor connected to the second resistor.

The rotation angle sensor according to the eighth aspect is the sixth aspect.
In the rotation angle sensor described above, the potential difference adding circuit includes a second resistor having the same resistance connected to the ground side of one resistor and the power supply side of another resistor.

According to a ninth aspect of the present invention, there is provided a rotation angle sensor according to the first aspect.
9. The rotation angle sensor according to any one of claims 1 to 8, which is used for a rear wheel steering device or a front wheel active steering device of a vehicle.

[0018]

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a conceptual diagram of the present rotation angle sensor 1. The rotation angle sensor 1 measures the rotation angle of a measurement target (not shown).

The rotation angle sensor 1 mainly includes a first resistor 2, a second resistor 3, a first brush member 4, and a second resistor 2.
A brush member 5, a lever member 6, a voltage signal line 7, a first signal line 8, a first transmission line 9, a second signal line 10, a second transmission line 11, a switch circuit 12, 3 transmission line 13
And an ECU (Electric Control Unit) 15.

The first resistor 2 is made of a resistor formed in an arc shape, and similarly, the second resistor 3 is made of a resistor formed in an arc shape. The first resistor 2 and the second resistor 3 are arranged concentrically.
The gap between the first resistor 2 and the gap between the second resistor 3 is arranged at a position where they do not overlap with each other. Specifically, the gap between the first resistor 2 and the gap between the second resistors 3 is disposed at a position substantially symmetric with respect to the center Z of the first resistor 2 and the second resistor 3. Therefore, it is possible to measure the rotation angle of the measurement object that rotates 360 degrees or more without any intervention of a transmission adjustment device such as a gear. Further, since there is no need to use a transmission adjusting device such as a gear (a device for adjusting a transmission ratio; the same applies hereinafter), the rotation angle sensor 1 can be reduced in size, and furthermore, the rotation angle sensor 1 can be reduced. Can also be manufactured at low cost.

The first brush member 4 includes the first resistor 2 and the first
The first resistor 2 and the first signal line 8 are short-circuited so as to be in contact with the signal line 8. This first
When the object to be measured rotates, the brush member 4 is slid on the first resistor 2 and the first signal line 8 in accordance with the rotation of the object to be measured. Similarly, the second brush member 5
Are also provided so as to be in contact with the second resistor 3 and the second signal line 10, and short-circuit the second resistor 3 and the second signal line 10. When the measurement object rotates, the second brush member 5 is also slid on the second resistor 3 and the second signal line 10 in accordance with the rotation of the measurement object. The first brush member 4 and the second brush member 5 are attached to a lever member 6. Lever member 6
Is for sliding the first brush member 4 and the second brush member 5 in accordance with the rotation of the object to be measured, is formed in a rod shape, and is supported rotatably about the center Z as the rotation center.

As described above, the first operation is performed according to the rotation of the object to be measured.
Since the brush member 4 and the second brush member 5 are mechanically configured to slide on the first resistor 2 and the second resistor 3, respectively, the rotation angle of the measurement target when the power is turned off is determined. The rotation angle of the object to be measured at the time of turning on the power can be measured without storing it in a rewritable nonvolatile memory such as an EEPROM.

The voltage signal line 7 is connected to the first resistor 2 and the second
This is for applying a voltage to the resistor 3, and includes a first voltage signal line 7a and a second voltage signal line 7b. The first voltage signal line 7a is connected to the end 2a on the counterclockwise side of the first resistor 2, the end 3b on the clockwise side of the second resistor 3, and the terminal C, respectively. A positive power line 16 is connected to the terminal C, and the positive power line 16 is further connected to a positive pole 50 a of the battery 50. The second voltage signal line 7b includes a clockwise end 2b of the first resistor 2 and a clockwise end 3 of the second resistor 3.
a and the terminal D are connected to each other. A negative power line 17 is connected to the terminal D, and the other end of the negative power line 17 is connected to a negative pole 50 b of the battery 50.

The first signal line 8 and the first transmission line 9 are
A contact position between the resistor 2 and the first brush member 4 (hereinafter, referred to as a contact position)
This is referred to as a “first contact position”. ) It is for outputting the potential at Y1. The main portion of the first signal line 8 is disposed concentrically with the first resistor 2 and along the first resistor 2, and one end of the first signal line 8 is connected to the terminal A. I have. One end of a first transmission line 9 is connected to the terminal A, and the other end of the first transmission line 9 is connected to a first A / D converter 15a of the ECU 15.

On the other hand, the second signal line 10 and the second transmission line 1
Reference numeral 1 is for outputting a potential at a contact position (hereinafter, referred to as a "second contact position") Y2 between the second resistor 3 and the second brush member 5. A main portion of the second signal line 10 is provided concentrically with the second resistor 3 and along the second resistor 3. One end of the second signal line 10 is connected to the terminal B
It is connected to the. One end of a second transmission line 11 is connected to the terminal B, and the other end of the second transmission line 11 is connected to a second A / D converter 15b of the ECU 15.

The switch circuit 12 determines whether the first contact position Y1 and the second contact position Y2 (ie, the lever member 6) are rotating clockwise with respect to the neutral line (a kind of reference position) Q, or This is for determining whether the rotation is in a clockwise direction. The switch circuit 12 includes a switch member 12a, a resistor R, and a third signal line 12b.

The switch member 12a mechanically switches to an on state or an off state when the lever member 6 passes through the neutral line Q. Hereinafter, referring to FIG.
The switch member 12a will be described in detail. FIG.
FIG. 2 is a sectional view taken along line II-II in FIG. 1. As shown in FIG. 2, the switch member 12a mainly includes the switch body 1
2a1, the first contact member 12a2, and the second contact member 12
a3, a spherical member 12a4, and a holding member 12a5.

The switch body 12a1 is made of an insulating material and is rotatably supported via a rotating shaft 12a8. When the lever member 6 collides with the switch main body 12a1, the switch main body 12a1 rotates clockwise or counterclockwise. More specifically, when the lever member 6 passes through the neutral line Q from right to left, the lever member 6 collides with the upper left surface of the switch main body 12a1, and the switch main body 12a1 rotates counterclockwise ( FIG. 2A). On the other hand, when the lever member 6 passes through the neutral line Q from left to right, the lever member 6 collides with the upper right surface of the switch main body 12a1, and the switch main body 12a1 rotates clockwise (FIG. 2). (B)).

The first contact member 12a2 is connected to the switch body 1
2a1 is provided on the lower surface of the second contact member 12a3.
Is disposed at one end of the third signal line 12b. When the switch main body 12a rotates clockwise, the first contact member 12a2 and the second contact position 12a3 are in a contact state. That is, the switch member 12a is turned on. On the other hand, when the switch body 12a rotates counterclockwise, the second contact member 12a2 and the second contact position 12a3
Is in a non-contact state. That is, the switch member 12a2 is turned off.

As described in the "Prior Art" and "Problems to be Solved by the Invention" sections, in the conventional rotation angle sensor (potentiometer 90), the lever member 9 is used.
When 5 is at the position shown by the dotted line P, there is a problem that it is not possible to determine in which direction the lever member 95 is rotating with respect to the neutral line Q.

However, in the present rotation angle sensor 1, as described above, when the lever member 6 passes through the neutral line Q, the switch member 12a is switched to the ON state or the OFF state. Neutral line Q
, It is possible to determine whether the rotation is in a clockwise direction or a counterclockwise direction. Therefore, even when the measurement object rotates 360 degrees or more, if the rotation angle of the measurement object is smaller than 720 degrees, the rotation angle of the measurement object can be measured.

Since the switch member 12a is of a type that is mechanically switched to an on state or an off state, the state of the switch member 12a when the power is turned off is set to E.
The rotation direction of the lever member 6 with respect to the neutral line Q can be determined without storing in a rewritable nonvolatile memory such as an EPROM.

Spherical member 12a4 and holding member 12a5
Is for holding the switch member 12a in the ON state or the OFF state. The spherical member 12a4 is
This sphere 12a6 is composed of a sphere 12a6 and a wire 12a7.
a6 is connected to the lower left end of the switch body 12a1 by a wire 12a7. Two spaces communicated with each other are formed in the holding member 12a5.
2a4 depends on the state of the switch body 12a1.
Between the two spaces. Therefore, the present rotation angle sensor 1 has a simple structure (that is, it is inexpensive), and even if it is used for a device to which vibration is continuously applied, the vibration causes the switch member 12a to generate another switch. The state can be prevented from being switched to the state.

The third signal line 12b shown in FIG. 1 is for outputting the state of the switch member 12a to the ECU 15. The third signal line 12b is connected to a terminal E and a terminal F, respectively.
The positive terminal 50a is connected by a positive power line 16 and the terminal F and the negative terminal 50b of the battery 50 are connected by a negative power line 17. The resistance R is
It is connected in series between the terminal E and the switch member 12a.

The third transmission line 13 outputs the state of the switch member 12a to the ECU 15. One end of the third transmission line 13 is connected to the third signal line 12b, and the other end of the third transmission line 13 is connected to the third transmission line 13. It is connected to a third A / D converter 15c of the ECU 15. When the switch member 12a is on, a low-level potential 33a (see FIG. 3) is output to the third A / D converter 15c via the third transmission line 13, and the switch member 12a is turned off. In some cases, a high-level potential 33b (see FIG. 3) is output to the third A / D converter 15c via the third transmission line 13. Therefore, only by identifying the state of the switch member 12a, in other words, the potential 33 output via the third transmission line 13
By simply discriminating whether the signal is low or high (see FIG. 3), the lever member 6 (ie, the first contact position Y1 and the second contact position Y1) with respect to the neutral line (reference position) Q is determined.
The rotation direction of the contact position Y2) can be determined.

The ECU 15 determines the potential 3 output via the first transmission line 9, the second transmission line 11 and the third transmission line 13.
1, 32, and 33, the first A / D converter 15a and the second A / D converter 15a.
b, the third A / D converter 15c, the RAM 15d, and C
A PU 15e and a ROM 15f are provided.

The first A / D converter 15a is connected to the first transmission line 9
The second A / D converter 15b converts the potential (potential at the first contact position Y1) 31 output via the second transmission line 11 into a digital signal. This is for converting the potential (potential at the position Y2) 32 into digital data. The third A / D converter 15 c converts the signal of the potential 33 output via the third transmission line 13 into a digital signal.

The RAM 15d is a volatile memory in which data can be rewritten, and has a potential digitally converted by the first A / D converter 15a, a potential digitally converted by the second A / D converter 15b, and 3A / D converter 1
5c stores the potential digitally converted.

The CPU 15e is a device for performing arithmetic processing and control processing, and includes a first A / D converter 15a, a second A / D converter
A process of calculating (measuring) the rotation angle of the measurement target based on the potential digitally converted by the D converter 15b and the third A / D converter 15c. Note that the CPU 15e may further control the rotation of the measurement target based on the result of the calculation (measurement).
The ROM 15f is a non-rewritable non-volatile memory, and the ROM 15f stores (stores) a control program executed by the rotation angle sensor 1 and the like.

FIG. 3 is a diagram showing the waveform of the output potential of the rotation angle sensor 1. In detail, FIG. 3A shows the potential 31 output via the first transmission line 9 and the second transmission line 11
FIG. 3 is a diagram showing a potential 32 output through
(B) is a potential 33 output via the third transmission line 13.
FIG. As shown in FIG. 3A, the potential 31 output via the first transmission line 9 has a waveform in which a plurality of straight lines rising to the left are intermittent, and the potential 32 output via the second transmission line 11. Has a waveform in which a plurality of straight lines rising upward are intermittent.

First, the potential 31 output via the first transmission line 9 will be described in detail. When the first brush member 4 is rotating clockwise, the potential 31 output via the first transmission line 9 is equal to the potential of the first brush member 4.
When it is on the resistor 2 (i.e., when the first brush member 4 is slid on the first resistor 2), the potential 31 output via the first transmission line 9 decreases. . On the other hand, in such a case, when the first brush member 4 is not on the first resistor 2, the first transmission line 9 is opened, and the potential 31 output via the first transmission line 9 becomes indefinite. (In FIG. 3, it is temporarily represented by a broken line.) Naturally, when the first brush member 4 is rotating in the counterclockwise direction and the first brush member 4 is on the first resistor 2, the potential 31 output via the first transmission line 9 is applied. Increases. Also,
The potential 32 output via the second transmission line 11 has a symmetrical waveform with the neutral line Q2 as the axis of symmetry.

As described above, FIG. 3B shows the third transmission line 13.
FIG. 3B is a diagram showing a potential 33 output through the third transmission line 13 as shown in FIG. 3B. The potential 33 output through the third transmission line 13 is at a high level on the left side of the neutral line Q2. The potential 33b becomes the low level potential (0V in this embodiment) 33a on the right side of the neutral line Q2.

By the way, the first transmission line 9 in the phase θ1
And the potential 32 outputted via the second transmission line 11 and the potential 31 outputted via the first transmission line 9 and the second transmission line 11 in the phase θ2.
Is the same as the potential 32 output via the.
Here, the phase difference between the phase θ1 and the phase θ2 is 360 degrees. That is, the conventional rotation angle sensor (potentiometer 9)
0), the potential 31 output via the first transmission line 9 and the potential 32 output via the second transmission line 11
With only this, the phase θ1 and the phase θ2 could not be distinguished. Therefore, when the lever member 6 that slides the first brush member 4 and the second brush member 5 rotates 360 degrees or more, the phase (angle) of the lever member 6 cannot be measured.

However, in the present rotation angle sensor 1, the phase θ 1 and the phase θ 2 can be distinguished by the potential 33 output via the third transmission line 13, so that the lever member 6 rotates 360 degrees or more. Also in this case, the phase (angle) of the lever member 6 can be measured. That is, even when the measurement object rotates 360 degrees or more, the rotation angle of the measurement object can be measured if the rotation angle of the measurement object is smaller than 720 degrees.

Next, the operation of the rotation angle sensor 1 configured as described above will be described with reference to FIGS. Specifically, a case where the measurement target rotates 360 degrees will be described.

When the object to be measured rotates, the lever member 6 located at the position shown by the dotted line P according to the rotation of the object to be measured.
Rotates clockwise. When the lever member 6 rotates, the lever member 6 causes the first member attached to the lever member 6 to rotate.
The brush member 4 and the second brush member 5 are rotated clockwise about the center Z. When the first brush member 4 and the second brush member 5 are rotated, the first brush member 4 is slid on the first resistor 2 and the first signal line 8, while the second brush member 5 is rotated. Is slid on the second resistor 3 and the second signal line 10. Here, the fact that the first brush member 4 is slid on the first resistor 2 and the first signal line 8 means that the first contact position Y
1 means that the second brush member 5 slides on the second resistor 3 and the second signal line 10 means that the second contact position Y2 changes. is there. Therefore, the first brush member 4 and the second
When the brush member 5 is slid, the potential 31 output via the first signal line 8 and the potential 32 output via the second signal line 10 change. The potential 31 output via the first signal line 8 is further applied to the first A via the first transmission line 9.
To the first A / D converter 1a.
The digital conversion is performed by 5a. Similarly, the second signal line 1
The potential 32 output through the second transmission line 11
And transmitted to the second A / D converter 15b via the second
It is digitally converted by the A / D converter 15b. 1A
The rotation angle of the lever member 6, that is, the rotation angle of the measurement target is calculated by the CPU 15e based on the potential digitally converted by the / D converter 15a and the potential digitally converted by the second A / D converter 15b. You.

When the lever member 6 passes through the neutral line Q, the lever member 6 collides with the switch main body 12a1, and the switch main body 12a1 changes from the state shown in FIG. 2A to the state shown in FIG. 2B. That is, the switch member 12a changes from the off state to the on state. When the switch member 12a changes, the potential 33 transmitted via the third transmission line 13 also changes from the high-level potential 33b to the low-level potential 33a. When the measurement object has been rotated by 360 degrees, the lever member 6 moves to the position indicated by the dotted line P again after passing through the neutral line Q.

As the measurement object rotates 360 degrees, the lever member 6 rotates clockwise from the position indicated by the dotted line P and moves again to the position indicated by the dotted line P.
In this case, the potentials 31 and 32 output via the first transmission line 9 and the second transmission line 11 before the measurement target rotates.
And the first transmission line 9 and the second transmission line 9 after the measurement object rotates.
The potentials 31 and 32 output via the transmission line have the same value. However, as described above, when the lever member 6 passes through the neutral line Q, the potential 33 output via the third transmission line 13 changes from the high level to the low level. After that, it can be distinguished. That is, even when the measurement object rotates 360 degrees or more, the rotation angle of the measurement object is 7 degrees.
If it is smaller than 20 degrees, the rotation angle of the measurement object can be measured.

Next, a rotation angle sensor 20 according to a second embodiment will be described with reference to FIGS. FIG. 4 is a conceptual diagram of the rotation angle sensor 20 of the second embodiment, and FIG.
FIG. 3 is a diagram illustrating a waveform of an output potential of a rotation angle sensor.
The rotation angle sensor 20 according to the second embodiment is different from the rotation angle sensor 1 according to the first embodiment in that the processing performed when the switch member 12a is turned on or off is changed. Hereinafter, the same portions as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 4, the rotation angle sensor 20 includes a first resistor 2, a second resistor 3, a first brush member 4, a second brush member 5, a lever member 6, The voltage signal line 27, the third resistor R1, the second resistor R2, the third resistor R1, the second signal line 10, the second switch circuit 23,
The switch circuit 12 and the ECU 25 are provided.

The voltage signal line 27 is adjusted so that the direction of increase or decrease of the potential 51 output via the first signal line 8 and the direction of increase or decrease of the potential 52 output via the second signal line 10 match.
A voltage is applied to the first resistor 2 and the second resistor 3, and a first voltage signal line 27a and a second voltage signal line 27b
And The first voltage signal line 27a is connected to a third resistor R
1 and a clockwise end 2b of the first resistor 2;
A clockwise end 3b of the second resistor 3 and a terminal C
Each is connected. On the other hand, the second voltage signal line 27b
Are connected to one end of the second resistor R2, the counterclockwise end 2a of the first resistor 2, and the terminal D, respectively.

The other end of the second resistor R2 is at the counterclockwise end 3a of the second resistor 3, the other end of the third resistor R1 is at the clockwise end 2b of the first resistor 2, Each is connected. The resistance value of the second resistor R2 and the resistance value of the third resistor R1 are equal to each other. The second resistor R2 adds a predetermined value of potential to the potential at the second contact position Y2, and the third resistor R1 determines the ratio of the potential change when the first contact position Y1 changes and the second contact position. This is for equalizing the rate of potential change when Y2 changes.
Therefore, by setting the resistance value of the second resistor R2 and the resistance value of the third resistor R1 to appropriate values, a part of the potential 51 output via the first signal line 8 and the second signal line 10 are connected. As shown in FIG. 5, a part of the potential 52 output via the terminal can be overlapped. This also allows the ECU
25 (CPU 25b) can be prevented from performing complicated arithmetic processing. Here, simplifying the processing performed by the ECU 25 means that the memory can be effectively used, and furthermore,
The program executed by the rotation angle sensor 20 can be simplified, that is, the development and design costs (particularly, labor costs) of the rotation angle sensor 20 can be reduced.

Note that the first resistor R1 and the second resistor R1
There is no need to provide the resistor R2, and only the first resistor or the second resistor may be provided. In this case,
The resistance values of the first resistor and the second resistor are values obtained by adding the resistance value of the first resistor R1 and the resistance value of the second resistor R2.

The first transmission line 21 transmits the potential 51 output via the first signal line 8 to the fourth transmission line 26. One end of the first transmission line 21 is connected to the terminal A, Transmission line 2
The other end of each 1 is connected to a contact 23a of the second switch circuit 23, respectively. Similarly, the second transmission line 22 is connected to the second
The potential 52 output via the signal line 10 is transferred to the fourth transmission line 2
6, one end of the second transmission line 22 is connected to the terminal B, and the other end of the second transmission line 22 is connected to the contact 23b of the second switch circuit.

The second switch circuit 23 is connected to the third transmission line 13
Of the potential 51 output through the first signal line 8 or the potential 52 output through the second signal line 10 based on the potential (ie, the state of the switch member 12a) 33 output through This is for transmitting any one potential to the fourth transmission line 26.

Specifically, when the potential 33 output via the third transmission line 13 is the high level potential 33b, the second switch circuit 23 switches to the contact 23a side, and the first signal line 8 Is transmitted to the fourth transmission line 26 via the. On the other hand, when the potential 33 output via the third transmission line 13 is the low-level potential 33a, the second switch circuit 23 switches to the contact 23b side and is output via the second transmission line 10. Potential 52
This is transmitted to the transmission line 26.

The ECU 25 performs various processes based on the potential 33 output via the third transmission line 13 and the potential output via the fourth transmission line 26.
/ D converter 25a, third A / D converter 15c, RA
M15d, CPU 25b, and ROM 15f. The fourth A / D converter 25a converts the potential output via the fourth transmission line 26 into a digital signal. C
The PU 25 b switches the second switch circuit 23 based on the potential 33 output via the third transmission line 13, and further switches the potential 33 output via the third transmission line 13 and the second A process for calculating (measuring) the rotation angle of the object to be measured based on the potential output via the four transmission lines 26 is performed. Therefore, the potential 51 output via the first signal line 8 and the potential 52 output via the second signal line 10 can be processed as one signal. That is, when measuring the rotation angle of the measurement object, the CP
U25b can be prevented from performing complicated arithmetic processing.

As described above, the second switch circuit 2
3 is performed based on the state of the switch member 12a. The switch member 12a is connected to a potential 51 output via the first signal line 8 and a potential 52 output via the second signal line 10. It is only necessary to switch while the is overlapping. Therefore, it is possible to prevent the need for precise mounting position accuracy when mounting the switch member 12a, and to ignore a time delay (time lag) when switching the switch member 12a. You can do it.

As described above, the present invention has been described based on the embodiments. However, the present invention is not limited to the above embodiments, and various improvements and modifications can be made without departing from the gist of the present invention. Can be easily inferred.

For example, in this embodiment, the CPU 25
The switching timing of the second switch circuit 23 is determined by b. However, the second switch circuit 23
Does not necessarily need to be determined by the CPU 25b. Specifically, the CPU 25b
, The second switch circuit 23 may be switched in conjunction with the switching of the switch member 12a.

In this embodiment, the second switch circuit 23 uses the potential 51 output via the first signal line 8 or the potential 51 based on the potential 33 output via the third transmission line 13. 2 potential 5 output via signal line 10
Any one of the two potentials is transmitted to the fourth transmission line 26. That is, the first signal line 8 is controlled by the second switch circuit 23.
, Or one of the potentials 52 output through the second signal line 10 is selected. However, such selection does not necessarily have to be performed by the second switch circuit 23, and the potential 51 output via the first signal line 8 and the potential 52 output via the second signal line 10 are each digital. When the conversion is performed, the selection may be made by the CPU 25b.

Further, in this embodiment, the rotation angle sensors 1 and 20 are provided with the first resistor 2 and the second resistor 3. The first resistor 2 and the second resistor 3 are concentric so that the rotation angle of the measurement object can be measured even if the measurement object rotates slightly 720 degrees.
In addition, the gap between the first resistor 2 and the gap between the second resistor 3 is disposed at a position substantially symmetric with respect to the center Z. However, when the measurement object rotates 720 degrees or more,
Apart from the first resistor 2 and the second resistor 3, an arc-shaped resistor may be provided concentrically with the first resistor 2 and the second resistor 3. Naturally, in this case, the potential output via the third transmission line 13 is changed in three or more steps.

The rotation angle sensors 1 and 20 described in this embodiment may be used in a rear wheel steering device or a front wheel active device of a vehicle. By using the rotation angle sensors 1 and 20 for a rear wheel steering device or a front wheel active steering device, a rear wheel steering device that does not malfunction even under a situation where vibration is continuously applied and that can increase the steering angle compared to the related art. Alternatively, a front wheel active device can be provided. That is, the effect and safety (including the meaning of reliability) of the rear wheel steering device or the front wheel active device can be enhanced.

[0064]

According to the rotation angle sensor according to the first aspect, when the brush member is slid on the resistor according to the rotation of the measurement target, the contact between the resistor and the brush member is determined by the determination device. It is determined whether the position is changing in the clockwise direction or the counterclockwise direction with respect to the reference position. Therefore, there is an effect that the rotation angle of the measurement object can be measured even when the measurement object rotates 360 degrees or more. Further, since the brush member is configured to slide on the resistor according to the rotation of the measurement target, the rotation angle of the measurement target when the power is turned off is stored in a storage device or the like. Even without this, there is an effect that the rotation angle of the measurement object when the power is turned on can be measured.

According to the rotation angle sensor of the second aspect, in addition to the effect of the rotation angle sensor of the first aspect,
Since the gap between the one resistor and the gap between the other resistors are arranged so as not to overlap with each other, a transmission adjusting device such as a gear (a device for adjusting (enlarging or decreasing) the transmission ratio) ) Has an effect that the rotation angle of the measurement object that rotates 360 degrees or more can be measured without the intervention of (2). Therefore, there is an effect that the present rotation angle sensor can be manufactured at low cost.

According to the rotation angle sensor according to the third aspect, in addition to the effect of the rotation angle sensor according to the first or second aspect, the switch member is turned on or off depending on the contact position of the resistor and the brush member. Since the state is switched to the state, the rotation direction of the contact position between the resistor and the brush member with respect to the reference position can be determined only by determining the state of the switch member.

According to the rotation angle sensor according to the fourth aspect, in addition to the effect of the rotation angle sensor according to any one of the first to third aspects, the switch member is mechanically switched to an on state or an off state. Since it is of the type, it is possible to determine the rotation direction of the contact position of the resistor and the brush member with respect to the reference position without storing the state of the switch member when the power is turned off in a storage device or the like. There is.

According to the rotation angle sensor of the fifth aspect, in addition to the effect of the rotation angle sensor of the fourth aspect,
Since the switch member is held at the position where the switch member is switched to the on state or the off state by the holding member, even if the switch member is used in an apparatus which is continuously vibrated despite its low cost, the vibration causes the switch member to be in another state. There is an effect that switching to a state can be prevented.

According to the rotation angle sensor according to the sixth aspect, in addition to the effects of the rotation angle sensor according to any one of the first to fifth aspects, furthermore, the direction of increase and decrease of the potential at one contact position and the other contact angle The potential increase / decrease direction at the position is made to coincide with each other, and the potential at one contact position to which the potential difference is added by the potential difference adding circuit, or the potential at another contact position is selected. There is an effect that a potential at another contact position (that is, an output signal of the present rotation angle sensor) can be processed as one signal. Therefore, there is an effect that complicated calculation processing when measuring the rotation angle of the measurement target can be eliminated.

When the selection of the potential by the selection device is selected according to the state of the switch member, the switching of the switch member is performed while the potential at one contact position and the potential at another contact position overlap. Therefore, there is an effect that it is possible to prevent the necessity of fine mounting position accuracy when mounting the switch member, and to allow a time delay (time lag) when switching the switch member. There is also an effect that can be done.

According to the rotation angle sensor of the seventh aspect, in addition to the effect of the rotation angle sensor of the sixth aspect,
A second resistor in which the potential difference adding circuit is connected to one of the ground side of one resistor or the power supply side of another resistor, or the ground side of one resistor and the power supply side of another resistor Since it is composed of a body, there is an effect that complicated arithmetic processing can be prevented from being performed in order to add a potential at another contact position to a potential at one contact position.

According to the rotation angle sensor of the eighth aspect, in addition to the effect of the rotation angle sensor of the sixth aspect, furthermore,
Since the potential difference adding circuit is composed of the third resistor having the same resistance value connected to the ground side of one resistor and the power supply side of another resistor, the potential at one contact location is changed to another contact location. There is an effect that complicated arithmetic processing can be prevented from being performed because the potential is added.

According to the rotation angle sensor according to the ninth aspect, in addition to the effect of the rotation angle sensor according to any one of the first to eighth aspects, the rotation angle sensor according to any one of the first to eighth aspects is further provided. By using a sensor for a rear wheel steering device or a front wheel active steering device, there is provided a rear wheel steering device or a front wheel active device that does not malfunction even under a situation where vibration is continuously applied and can provide a larger steering angle than before. There is an effect that can be. That is, there is an effect that the effect of the rear wheel steering device or the front wheel active device can be enhanced.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a rotation angle sensor according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a diagram showing a waveform of an output potential of the rotation angle sensor.

FIG. 4 is a conceptual diagram of a rotation angle sensor according to a second embodiment.

FIG. 5 is a diagram illustrating a waveform of an output potential of a rotation angle sensor according to a second embodiment.

FIG. 6 is a conceptual diagram of a conventional rotation angle sensor.

[Explanation of symbols]

1,20 rotation angle sensor 2 first resistor (resistor, another resistor) 3 second resistor (resistor, one resistor) 4 first brush member (brush member) 5 second brush member (brush) 12) Switch circuit (part of discrimination device) 12a Switch member 12a4 Spherical member (part of holding member) 12a5 Holding member (part of holding member) 15e, 25b CPU (part of discrimination device, one of selection device) Part) 23 second switch circuit (part of the selection device) 27 voltage signal line (signal line) Q neutral line (reference position) R1 third resistor (part of third resistor and potential difference adding circuit) R2 second Resistance (part of third resistor and potential difference adding circuit) Y1 First contact position (another contact position) Y2 Second contact position (a single contact position)

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F063 AA35 CA10 CA40 DA05 EA03 FA01 2F077 AA27 AA37 CC02 EE02 VV02

Claims (9)

[Claims] 1. A plurality of resistors formed in an arc shape and arranged concentrically, a brush member slid on the resistors according to the rotation of an object to be measured, the resistor and the brush A rotation angle sensor comprising: a determination device configured to determine whether the contact position of the member is changing in a clockwise direction or a counterclockwise direction with respect to the reference position. 2. The rotation angle sensor according to claim 1, wherein the gap between the one resistor and the gap between the other resistors are arranged so as not to overlap with each other. 3. The device according to claim 1, wherein the discriminating device includes a switch member that switches between an on state and an off state when a contact position between the resistor and the brush member passes a reference position. A rotation angle sensor as described. 4. The rotation angle sensor according to claim 1, wherein the switch member is of a type that mechanically switches between an on state and an off state. 5. The rotation angle sensor according to claim 4, further comprising a holding member that holds the switch member at a position where the switch member is turned on or off. 6. A signal line connected such that the direction of increase and decrease in potential at the contact position of one resistor and the brush member and the direction of increase and decrease of potential at the contact position of another resistor and brush member coincide with each other; A potential difference adding circuit for adding a potential difference between the potential at the one contact position and the potential at the other contact position to the potential at the one contact position; and a potential at the one contact position to which the potential difference is added by the potential difference adding circuit, or The rotation angle sensor according to claim 1, further comprising a selection device that selects a potential at the another contact position. 7. A potential difference adding circuit is provided on either one of the ground side of one resistor or the power supply side of another resistor, or the ground side of one resistor and the power supply side of another resistor. 7. The rotation angle sensor according to claim 6, comprising a connected second resistor. 8. A potential difference adding circuit comprising a third resistor having the same resistance connected to the ground side of one resistor and the power supply side of another resistor. A rotation angle sensor as described. 9. The rotation angle sensor according to claim 1, wherein the rotation angle sensor is used for a rear wheel steering device or a front wheel active steering device of a vehicle.