JPH02290146A - Frequency generator - Google Patents

Abstract

PURPOSE:To make a signal output uniform both in period and in amplitude by forming the radial extensions of two outgoing lines connected with a magneto coil into the same shape respectively and by letting each radial extension electrically have a phase difference by (360/n)Xm degrees [m=1, 2,...(n-1)]. CONSTITUTION:The beginning and terminating ends of a magneto coil 28 are connected with signal output terminals 70a, 70b via outgoing lines 71a, 71b. In this case, the extended parts of the outgoing lines 71a, 71b are respectively formed into the same shape and electrically have a phase difference by 360 deg. circumferentially to each other. Therefore, a generated voltage is cancelled in the extended parts of the outgoing lines. Moreover, when the phase of the effective generating part 27 of the magneto coil 28 and that of the pole boundary line 124 of a frequency generator(FG) magnetic pole 125 coincide with each other and the generated voltage in the effective generating part is zero, the extended parts are also positioned on the boundary line so that no electricity is not generated in the outgoing line. Therefore, FG signal is not disturbed in its period. Consequently, the variation of the FG signal diminishes both in period and in amplitude.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a frequency generator (hereinafter abbreviated as FG) that is optimal for use in motors and the like.

2. Description of the Related Art In recent years, motors equipped with frequency generators (hereinafter abbreviated as FG) as means for detecting the rotational frequency of rotor magnets have been used to drive cab stuns, rotating head drums, etc. of video tape recorders (hereinafter abbreviated as VTRs). It is now widely used in Japan and is small in size. There is a strong demand for lighter weight and higher performance. Along with this, there is an increasing need to develop compact and highly accurate FGs.

As a conventional FG that is smaller and lighter but has relatively good accuracy in detecting rotational angular velocity, a ring-shaped FG magnet is magnetized with multiple poles at equal pitches on one plane and fixed to the rotor. The plane-opposing full-circumference integral type FG, in which a zigzag comb-tooth coil is disposed with a certain gap between the magnetic poles of the FG magnet, is well known, and is used as a motor for driving the rotating head drum of a VTR. etc. has been adopted.

FG used in conventional motors will be explained below with reference to the drawings.

In FIG. 12, a rotating magnet 2 is attached to a shaft 25 rotatably supported by a motor 100 via a rotor yoke 26.
4 is fixed. Also, the motor 100 has a mounting member 10.
A fixed substrate 40 is fixed via 1. As shown in FIG. 15, the rotating magnet 24 is provided with FG magnetic poles 125 arranged in a fan shape at equal pitches. In this example, the rotating magnet 24 is magnetized to have 16 poles.

Further, as shown in FIG. 13, the generating coil 28 and the lead wire 7 are etched on the flat surface of the fixed substrate 40.
1a, 71bt Signal output terminal 70a. 70b is installed. Here, the power generation coil 28 includes 16 effective power generation sections 27 arranged at equal pitches so as to be parallel to the magnetic pole boundary line 124 of the FG magnetic pole 125 of the rotating magnet 24, and the effective power generation sections 27 that are electrically connected to each other. It forms a comb structure consisting of a reactive power generation section 33 connected to Also, the power generation coil 28
The starting end and the ending end of the lead line 71a. It is electrically connected to signal output terminals 70a and 70b via 7lb.

The operation in the above configuration will be explained. The magnetic flux of the rotating magnet 24 interlinks with the effective power generation portion 27 of the power generation coil 28 disposed on the fixed substrate 40 . Here, when the motor 100 is rotationally driven, the magnetic flux interlinking with the generating coil 28 changes due to this rotation, so that a rotation frequency signal (hereinafter referred to as FG) having a frequency proportional to the rotational speed of the motor 100 is sent to the generating coil 28.
(abbreviated as signal) is generated.

This FG signal is input to a drive control circuit (not shown) of the motor 100, and the rotation of the motor 100 is controlled so that the period of this signal becomes a predetermined value.

Problems to be Solved by the Invention However, the above conventional example has the following drawbacks.

That is, when the rotor is not dynamically balanced, when the motor 100 rotates, centrifugal force is generated, the shaft 25 is elastically deformed, and the center of the rotating magnet 24 and the center of rotation of the shaft 25 are misaligned. Also, even when dynamic balance is achieved, the rotating magnet 2
4 is attached to the rotor yoke 28 with a shift, the center of the rotating magnet 24 and the center of rotation of the shaft 25 will also shift.

In this case, as shown in FIG. 14, the FG magnetic pole 125 of the rotating magnet 24
It shifts from the center of 8 (P).

Then, the phase of the effective power generation line element 27 of the power generation coil 28,
The phases of the magnetic pole boundary lines 124 of the rotating magnet 24 may match and may not match.

As a result, the period of the FG signal is no longer constant, and even if the motor 100 rotates at a constant rate, a phase with a long period and a phase with a short period will occur during one rotation.

As described above, if the FG signal does not have a frequency that is accurately proportional to the rotation period of the motor 100, the motor 100 will rotate unevenly, resulting in a problem that the performance of the device cannot be satisfied.

Further, as shown in FIG. 16, when the outermost circumference of the effective power generation section 27 of the power generation coil 28 does not have a sufficient length to cover the outer diameter of the rotating magnet 24, the lead wire 71a
．． 7lb is interlinked with leakage magnetic flux from the rotating magnet 24, and this lead wire 71a. Even 7lb generates electricity.

Here, consider a case where the center of the rotating magnet 24 does not coincide with the center of rotation of the shaft 25, or a case where the magnetization strength of each F'G magnetic pole 125 is not constant. As shown by the solid line in FIG. 17, the power generation voltage in the effective power generation section 27 of the power generation coil 28 increases due to the full circumference integral effect due to the fact that the effective power generation section 27 of the power generation coil 28 is arranged at equal pitches over the entire circumference. signal 20
At 0, a waveform with a relatively constant period and constant amplitude is obtained.

However, as shown in FIG. 16, the phase of the effective power generation section 27 of the power generation coil 28 and . Even when the phase of the magnetic pole boundary line 124 of the FG magnetic pole 125 matches and the generated voltage in the growth power generation section 27 is 0, the lead wire 7! a,7
lb is one pole of the FG magnetic pole 125 (N pole in the figure)
Since it straddles the top, the leader line 71a. It generates electricity at 7lb. Here, the center of the rotating magnet 24 is the axis 2
5 or when the magnetization strength of each FG magnetic pole 125 is not constant, as shown by the dashed line in FIG. 17, the lead line 71a. The noise voltage 201 at 7 lb changes greatly in period and amplitude during one revolution of the motor 100.

Therefore, signal output terminal 70a. FG output to 70b
As shown by the broken line in FIG. 17, the signal 202 has large fluctuation components in both period and amplitude.

As described above, if the FG signal does not have a frequency that is accurately proportional to the rotation period of the motor 100, the motor 100 will rotate unevenly, resulting in a problem that the performance of the device cannot be satisfied.

SUMMARY OF THE INVENTION In view of the above-mentioned problems, it is an object of the present invention to improve the detection accuracy of rotational frequency without causing unevenness in the period and amplitude of the FG signal output.

Means for Solving the Problems The technical means of the first invention for solving the problems described above is a 2n-pole magnet electrically connected to a power generating coil on a fixed substrate placed opposite a rotating magnet magnetized to 2n poles. The radial extending portions of the book lead lines are each made into approximately the same shape, and 360/n×m (
degrees) (m=t. 2+ ... (n-1)) so as to have a phase difference from each other in the circumferential direction.

Moreover, the technical means of the second invention to solve the above problem is as follows:
Annular connecting parts are provided on the front and back sides of the fixed substrate on which the generating coil is arranged, and are concentric with the generating coil and electrically connected to the starting and ending ends of the generating coil, respectively. and a signal output terminal disposed on the fixed substrate are electrically connected to each other.

Moreover, the technical means of the third invention for solving the above problem is as follows:
When the rotating magnet rotates and the innermost peripheral end of the effective power generating part of the power generating coil and the innermost peripheral end of the magnetic pole boundary line of the rotating magnet are in the same phase, the effective power generating part of the power generating coil, The magnetic pole boundary lines of the rotating magnet are configured so as not to be parallel to each other.

Further, the technical means of the fourth invention for solving the above problem is as follows:
A power generating coil is disposed on the first flat surface of the fixed substrate, and a circular yoke plate made of a magnetic material and concentric with the power generating coil is disposed on the second flat surface, and the inner diameter of the yoke plate is It is configured to have a diameter larger than the diameter of the innermost circumference of the effective power generation section of the power generation coil.

Effect The effect of the technical means of the first invention is that by electrically connecting the lead wire to the power generation coil, the phase of the effective power generation portion of the power generation coil matches the phase of the magnetic pole boundary line of the FG magnetic pole, Even when the generated voltage in the effective power generation section is 0, the two lead wires straddle the two poles of the FG magnetic poles of mutually different polarities, and have a phase difference of 360×m (degrees) in electrical angle. Therefore, the generated voltages at the two lead lines cancel each other out.

In addition, the effect of the technical means of the second invention is to arrange an annular connection part on the fixed substrate with front and back sides, and to electrically connect the power generation coil and the signal output terminal by this connection part. By doing so, it becomes possible to eliminate the radial extending portion that contributes to power generation, and only the generated voltage signal in the effective power generation portion is transmitted to the signal output terminal.

Further, the effect of the technical means of the third invention is such that the rotating magnet rotates, and the innermost circumferential end of the effective power generation portion of the power generating coil and the innermost circumferential end of the magnetic pole boundary line of the rotating magnet are in the same phase. By configuring the generator coil's spine power generating section and the magnetic pole boundary line of the rotating magnet so that they are not parallel to each other, even when the center of the rotating magnet does not coincide with the center of rotation of the shaft, each effective The phase shift of the generated voltage waveform in the power generation section is alleviated.

Furthermore, the effect of the technical means of the fourth invention is that the power generating coil is placed on the first plane part of the fixed substrate, and the power generating coil is arranged concentrically with the power generating coil in the second part 1L of the fixed substrate. By disposing an annular yoke plate and setting the inner diameter of the yoke plate to be larger than the diameter of the innermost circumference of the effective power generation part of the power generation coil, the center of the rotating magnet is the center of rotation of the shaft. Even when they do not match, the magnetic flux linking to the outer circumference of the effective power generation part of the power generation coil, which contributes most to power generation, is focused on the yoke plate arranged concentrically with the power generation coil, so each effective power generation of the power generation coil is The phase shift and amplitude fluctuation of the generated voltage waveform in the region are alleviated.

Example An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a frequency generator (hereinafter referred to as FG) in a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of a motor equipped with a 1st
In the figure, a shaft 2 rotatably supported by a motor 100
A rotating magnet 24 is fixed to the rotor 5 via a rotor yoke 26. As shown in FIG. 2, 2n fan-shaped FG magnetic poles 125 are provided on the rotating magnet 24 at equal pitches. The rotating magnet 24 here is magnetized to have 16 poles. That is, n=8.

Further, a fixed substrate 40 is fixed to the motor 100 via a mounting member 101. Here, on the flat surface of the fixed substrate 40, the generating coil 28, the lead wire 71a. 7lb. Signal output terminal 70a. 70b
are arranged. Here, the power generation coil 28 includes 16 effective power generation sections 27 arranged at equal pitches so as to be parallel to the magnetic pole boundary line 124 of the FG magnetic pole 125 of the rotating magnet 24, and the effective power generation sections 27 that are electrically connected to each other. Reactive power generation section 3 connected to
It forms a comb-teeth cane consisting of 3. Further, the starting end and the ending end of the generating coil 28 are connected to a signal output terminal 70a through lead wires 71a and 7lb. 70b.

Here, the lead wires 71a and 7lb each have substantially the same shape in their radial extending portions, and have a diameter of 380/n×m (degrees).
They have a phase difference from each other in the circumferential direction by (m=t, 2, . . . (n-1)). In this embodiment, m=1. Therefore, in this example, 45@
Only by developing a mechanical phase difference.

In this embodiment, eight periods of FG signals are output to the signal output terminals 71a and 7lb during one rotation of the rotating magnet 24. Therefore, the leader line 71a. The 7 lb radial extension has an electrical phase difference of 360 @ in this example.

The operation of the frequency generator configured in this way will be explained below. The magnetic flux of the rotating magnet 24 interlinks with the effective power generation portion 27 of the power generation coil 28 disposed on the fixed substrate 40 . here,
When the motor 100 is driven to rotate, the rotation changes the magnetic flux interlinking with the generator coil 28, so a rotation frequency signal (hereinafter abbreviated as FG signal) with a frequency proportional to the rotational speed of the motor 100 is generated in the generator coil 28. do.

This FG signal is input to a drive control circuit (not shown) of the motor 100, and the rotation of the motor 100 is controlled so that the period of this signal becomes a predetermined value.

If the FG signal does not have a frequency exactly proportional to the rotation period of the motor 100, the motor 100 will rotate unevenly, making it impossible to satisfy the performance of the device. Therefore, since the periodic accuracy of the FG signal needs to be extremely high, it is important to prevent unnecessary noise components from being superimposed on the FG signal.

By the way, the leader line 71a. 7lb is also interlinked with the leakage magnetic flux from the rotating magnet 24, and power is also generated at each of the radially extending portions of the lead wires 71a and 7lb.

However, in this embodiment, the radial extending portions of the two lead wires have substantially the same shape, and electrically
Since there is a phase difference of .degree., the lead lines 71a and 7l
The generated voltages in the radial extension part b cancel each other out.

Moreover, as shown in FIG. 2, when the phase of the effective power generation section 27 of the power generation coil 28 and the phase of the magnetic pole boundary line 124 of the FG magnetic pole 125 match, and the generated voltage in the effective power generation section 27 is O. Furthermore, since the radially extending portions of the lead wires 71a and 7lb are also located on the magnetic pole boundary line 124 of the FG magnetic pole 125, no power is generated in the lead wires 71a and 17lb. Therefore, the period of the FG signal is not disturbed.

That is, the FG output to the signal output terminals 70a and 70b
The signal is not affected by disturbance noise in the leader line, and fluctuations in both period and amplitude are extremely small, making it possible to improve the detection accuracy of the rotational frequency. Therefore, it becomes possible to improve the performance of the device.

In this way, according to this embodiment, it is possible to obtain a small, light, and high-performance FG with a very simple configuration.

Next, a second embodiment of the first invention will be described. In this embodiment, as in the first embodiment shown in FIG. 1, a rotating magnet 24 is fixed to a shaft 25 rotatably supported by a motor 100 via a rotor yoke 26. As shown in FIG. 3, 2n fan-shaped FG magnetic poles 125 are provided on the rotating magnet 24 at equal pitches. The rotating magnet 24 here is magnetized to have 16 poles. That is, n=8.

Further, a fixed substrate 40 is fixed to the motor 100 via a mounting member 101. Here, on the flat surface of the fixed substrate 40, the power generation coil 28, the lead wire 71a. 7lb. Signal output terminals 70a, 70b
are arranged. Here, the power generation coil 28 includes 16 effective power generation sections 27 arranged at equal pitches so as to be parallel to the magnetic pole boundary line 124 of the FG magnetic pole 125 of the rotating magnet 24, and the effective power generation sections 27 that are electrically connected to each other. Reactive power generation unit 3 connected to
It has a comb-like shape consisting of 3. Further, the starting end and the ending end of the generating coil 28 are electrically connected to signal output terminals 70a and 70b via lead wires 71a and 7lb.

Here, the lead wires 71a and 7lb each have a radially extending portion having substantially the same shape, that is, a spiral rod, and 36
0/n×m (degrees) (m=L 2t...(n-
They have a phase difference in the circumferential direction by 1)). In this embodiment, m=1.

Therefore, in this embodiment, there is a mechanical phase difference of 45 degrees. In this embodiment, during one rotation of the rotating magnet 24, the signal output terminals 71a and 7lb are supplied with 8 cycles of FG.
A signal is output. Therefore, in this embodiment, the radial extending portions of the lead wires 71a and 7lb are electrically 360@
It has a phase difference of

The operation of the frequency generator configured in this way will be explained below. The magnetic flux of the rotating magnet 24 interlinks with the effective power generation portion 27 of the power generation coil 28 disposed on the fixed substrate 40 . here,
When the motor 100 is driven to rotate, the magnetic flux interlinking with the generator coil 28 changes due to the rotation, so that the generator coil 28 receives an FG with a frequency proportional to the rotational speed of the motor 100.
A signal is generated.

This FG signal is input to a drive control circuit (not shown) of the motor 100, and the rotation of the motor 100 is controlled so that the period of this signal becomes a predetermined value.

If the FG signal does not have a frequency exactly proportional to the rotation period of the motor 100, the motor 100 will rotate unevenly, making it impossible to satisfy the performance of the device. Therefore, since the periodic accuracy of the FG signal needs to be extremely high, it is important to prevent unnecessary noise components from being superimposed on the FG signal.

By the way, the leakage magnetic flux from the rotating magnet 24 also interlinks with the lead wires 71a and 7lb, and power is generated also in the radially extending portions of the lead wires 71a and 7lb.

However, in this embodiment, the radial extending portions of the two lead wires have the same shape, and electrically
Since the lead wires 71a and 7lb have a phase difference of
The generated voltages in the radial extension of are mutually canceled.

Moreover, as shown in FIG. 3, the radial extending portions of the lead wires 71a and 7lb have a spiral shape,
Since the shape is very similar to a circular arc like the reactive power generation section 33 of No. 8, the generated voltage itself, which becomes a noise component in the lead lines 71a and 7lb, also has a small value. Therefore, the period of the FG signal is not disturbed.

That is, the signal output terminal 70a. FG output to 70b
The signal is not affected by disturbance noise in the leader line, and fluctuations in both period and amplitude are extremely small, making it possible to improve the detection accuracy of the rotational frequency. Therefore, it becomes possible to improve the performance of the device.

As described above, according to this embodiment, it is possible to obtain a compact, lightweight, and high-performance FG with a very simple configuration.

Next, an embodiment of the second invention will be described.

FIG. 6 is a cross-sectional view of a motor equipped with an FG in this embodiment. In FIG. 8, a rotating magnet 24 is fixed to a shaft 25 rotatably supported on a motor 100 via a rotor yoke 26. As shown in FIG. As shown in FIG. 15, fan-shaped FG magnetic poles 125 are provided on the rotating magnet 24 at equal pitches.

Further, a fixed substrate 40 is fixed to the motor 100 via a mounting member 101. Here, on the flat part of the fixed substrate 40 and on the side facing the rotating magnet 24,
As shown in the figure, the generator coil 28 is
, signal output terminal 70a, through hole 50, connection part 80
A and a are arranged. Here, the power generation coil 28 includes an effective power generation section 27 arranged at equal pitches so as to be parallel to the magnetic pole boundary line 124 of the rotating magnet 24, and a
It has a comb-like shape and consists of a reactive power generation section 33 that electrically connects the Further, the starting end of the generating coil 28 is electrically connected to the signal output terminal 70a via the connection part Boa. On the other hand, the terminal end of the generating coil 28 is electrically connected to the through hole.

Furthermore, the rotating magnet 24 is located on the flat surface of the fixed substrate 40.
As shown in FIG. 5, a signal output terminal 70b and a through hole 50 are formed on the side not facing the
, and a connecting portion 80b are provided, and these are electrically connected. Therefore, the terminal end of the generating coil 28 is electrically connected to the signal output terminal 70b via the through hole 50.

Note that the connection portion 80a. 8 0 b is in the form of a circular ring arranged concentrically with the power generating coil 28 .

The operation of the frequency generator configured in this way will be explained below. The magnetic flux of the rotating magnet 24 interlinks with the effective power generation portion 27 of the power generation coil 28 disposed on the fixed substrate 40 . here,
When the motor 100 is rotated, the magnetic flux interlinking with the generator coil 28 changes due to this rotation, so that an FG signal with a frequency proportional to the rotational speed of the motor 100 is generated in the generator coil 28. This FG signal is The signal is input to a drive control circuit (not shown) of the motor 100, and the rotation of the motor 100 is controlled so that the cycle of this FG signal becomes a predetermined value. If the FG signal does not have a frequency exactly proportional to the rotational frequency of the motor 100, the motor 100 will rotate unevenly, making it impossible to satisfy the performance of the device. Therefore, since the periodic accuracy of the FG signal needs to be extremely high, it is important to prevent unnecessary noise components from being superimposed on the FG signal.

By the way, in this embodiment, the output signal of the power generating coil 28 is transmitted to the signal output terminal 70a. The connecting portions 60a and 60b for transmitting data to the connecting portion 70b have an annular shape and do not have a radially extending portion, so that noise voltage is not generated in the lead wire as in the conventional example.

Therefore, the period of the FG signal is not disturbed. In other words, the FG signals output to the signal output terminals 70a and 70b are not affected by disturbance noise in the lead wires, and fluctuations in both period and amplitude are extremely small, making it possible to improve the detection accuracy of the rotational frequency. . Therefore, it becomes possible to improve the performance of the device.

In this way, this embodiment has a very simple configuration, yet is small, lightweight, and high-performance. It is possible to obtain G.

Next, an embodiment of the third invention will be described.

The configuration of the frequency generator in this embodiment will be explained using the drawings. As shown in FIG. 1, a rotor yoke 26 is connected to a shaft 25 rotatably supported on the motor 100.
A rotating magnet 24 is fixed.

As shown in FIG. 7, FG magnetic poles 125 are provided on the rotating magnet 24, magnetized at equal pitches.

Further, a fixed substrate 40 is fixed to the motor 100 via a mounting member 101. Here, on the flat surface of the fixed substrate 40, the power generation coil 28, the lead wire 71a. 7lb, signal output terminal 70a. 70b
are arranged. Here, the power generation coil 28 has a comb-teeth shape and is composed of an effective power generation section 27 arranged at equal pitches and a reactive power generation section 33 that electrically connects the effective power generation section 27. Further, the starting end and ending end of the generating coil 28 are connected to a signal output terminal 70a via lead wires 71a and 7lb.
, 70b.

Here, the relationship between the effective power generation portion 27 of the power generation coil 28 and the magnetic pole boundary line 124 of the rotating magnet 24 is as follows. In other words, the rotating magnet rotates and the generating coil 28
When the innermost circumferential end P of the effective power generation section 27 and the innermost circumferential end Q of the magnetic pole boundary line 124 of the rotating magnet 24 are in the same phase, the outermost circumferential end of the effective power generation section 27 of the power generation coil 28 T and the outermost peripheral end R of the magnetic pole boundary line 124 of the rotating magnet 24 have a phase difference Δ. In this embodiment, in order to have such a structure, the extension line of the effective power generation section 27 is set not to pass through the axis, and the magnetic pole boundary line 124 is also set not to pass through the axis.

The operation of the frequency generator configured in this way will be explained below. The magnetic flux of the rotating magnet 24 interlinks with the effective power generation portion 27 of the power generation coil 28 disposed on the fixed substrate 40 . here,
When the motor 100 is rotationally driven, the magnetic flux interlinked with the generator coil 28 changes due to the rotation, so that an FG with a frequency proportional to the rotational speed of the motor lOO is applied to the generator coil 28.
A signal is generated.

This FG signal is input to a drive control circuit (not shown) of the motor 100, and the rotation of the motor 100 is controlled so that the period of this signal becomes a predetermined value.

If the FG signal does not have a frequency exactly proportional to the rotation period of the motor 100, the motor 100 will rotate unevenly, making it impossible to improve the performance of the device. Therefore, the periodic accuracy of the FG signal must be extremely high.
There is a need.

If the rotor is not dynamically balanced, the motor 10
When 0 rotates, centrifugal force is generated and the shaft 25 is elastically deformed,
The center of the rotating magnet 24 and the center of rotation of the shaft 25 are misaligned. Furthermore, even when dynamic balance is achieved, if the rotating magnet 24 is attached with a deviation relative to the rotor yoke 2d, the center of the rotating magnet 24 and the center of rotation of the shaft 25 will also be deviated.

Here, in the conventional example, when the rotating magnet 24 is eccentric, each effective power generation section 2 of the power generation coil 28 as shown in FIG.
7 and the magnetic pole boundary line 124 of the FG magnetic pole 125 of the rotating magnet 24
The relative phase with respect to the power generation section 27 varies in each child power generation section 27. Therefore, a phase shift occurs in the generated voltage waveform in each effective power generation section 27, which is added over the entire circumference, and the signal output terminals 70a. A phase shift, that is, a periodic fluctuation has occurred in the FG signal output to the FG signal 70b.

On the other hand, in this embodiment, even if the rotating magnet 24 is eccentric, as shown in FIG.
24 is constructed so as not to be parallel to it. That is, each effective power generation section 27 intersects with the magnetic pole boundary line 124 at least at one point.

Therefore, fluctuations in the relative phase between each effective power generation section 27 and the magnetic pole boundary line 124 in each effective power generation section 27 are alleviated. That is, it becomes possible to reduce the phase shift of the generated voltage waveform in each effective generator 27.

Therefore, the influence of the eccentricity of the rotating magnet 24 on the period of the F/G signal is alleviated, and the fluctuations in both the period and amplitude become extremely small, making it possible to improve the detection accuracy of the rotational frequency, which in turn improves the performance of the equipment. It is also possible to improve.

As described above, according to this embodiment, it is possible to obtain a small, light ffi, and high-performance FG with a very simple configuration.

In this embodiment, the effective power generation section 27 and the magnetic pole boundary line 124 are both set so that their extension lines do not pass through the axis, but the present invention is not limited to this.
It may be either one. Further, although the effective power generation section 27 and the magnetic pole boundary line 124 are constructed as straight lines, they are not limited to this, and may be spiral shaped, for example.

Next, an embodiment of the fourth invention will be described.

FIG. 10 is a cross-sectional view of a motor equipped with F'G in this embodiment. In FIG. 10, a rotor yoke 28 is attached to a shaft 25 rotatably supported on the motor 100.
A rotating magnet 24 is fixed thereto. Rotating magnet 24
As shown in FIG. 15, fan-shaped FG magnetic poles 125 are provided at equal pitches on the top.

Further, a fixed substrate 40 is fixed to the motor 100 via a mounting member 101. Here, mW on the flat part of the fixed substrate 40 and facing the rotating magnet 24 is etched as shown in FIG.
8. Signal output terminal 70a. 70b are arranged. Here, the power generation coil 28 has a comb-teeth configuration, which is composed of an effective power generation section 27 arranged at equal pitches and a reactive power generation section 33 that electrically connects the effective power generation section 27.

Furthermore, the rotating magnet 24 is located on the flat surface of the fixed substrate 40.
As shown in FIG. 9, a yoke plate 80 made of a magnetic material and in the form of an annular cane is disposed concentrically with the generating coil 28 on the 41 paddle that does not face the yoke. Here, the inner diameter of the yoke plate is n. is larger than the diameter DI of the innermost circumference of the effective power generation section 27 of the power generation coil 28.

The operation of the frequency generator configured in this way will be explained below. The magnetic flux of the rotating magnet 24 interlinks with the effective power generation portion 27 of the power generation coil 28 disposed on the fixed substrate 40 . here,
When the motor 100 is rotationally driven, the magnetic flux interlinked with the generator coil 28 changes due to this rotation, so that the generator coil 28 is supplied with an FG with a frequency proportional to the rotational speed of the motor 100.
A signal is generated. This FG signal is input to a drive control circuit (not shown) of the motor 100, and the rotation of the motor 100 is controlled so that the period of this FG signal becomes a predetermined value. Here, if the amplitude of the FG signal is not constant and there is amplitude fluctuation during one rotation of the motor 100, the FG signal
The period of the signal also fluctuates, causing uneven rotation of the motor 100, making it impossible to satisfy the performance of the device. Therefore, the amplitude accuracy of the FG signal also needs to be extremely high. If the rotor is not dynamically balanced,
When the motor 100 rotates, centrifugal force is generated and the shaft 25 is elastically deformed, causing the center of the rotating magnet 24 and the center of rotation of the shaft 25 to deviate from each other. Furthermore, even when dynamic balance is achieved, if the rotating magnet 24 is attached with a deviation relative to the rotor yoke 2B, the center of the rotating magnet 24 and the center of rotation of the shaft 25 will also be deviated. Then, in the conventional example, the amount of magnetic flux interlinking with each of the effective linear portions 27 of the power generating coil 28 changes with rotation. Therefore, signal output terminal 70a. The amplitude of the FG signal output to the motor 70b is not constant, and
Amplitude fluctuations occurred during one rotation.

However, in this embodiment, since the annular yoke plate 80 made of magnetic material is arranged concentrically with the power generating coil 28, the leakage magnetic flux of the rotating magnet 24 is caused by the leakage magnetic flux as shown by the arrow in FIG. It is focused on the yoke plate 80. Moreover, yoke plate 80
Since the inner diameter of the power generating coil 28 is set larger than the diameter of the innermost circumferential portion of the power generating coil 28, the magnetic flux is focused on the outer peripheral side of the effective power generating section 27, which particularly contributes to power generation. Even if the rotating magnet 24 is eccentric, the amount of magnetic flux interlinking with each of the effective linear portions 27 of the rotating magnet 24 will not change significantly depending on the rotational phase of the rotating magnet 24. Therefore, the signal output Ω; 11 children 70a. Amplitude fluctuations occurring in the FG signal output to 70b are reduced. In other words, it is possible to improve the detection accuracy of the rotational frequency and, in turn, improve the performance of the device.

As described above, this embodiment has a very simple configuration and is small in size. It becomes possible to obtain a light FFI and high performance FG.

Effects of the Invention According to the frequency generator according to the first invention as described above,
Even when the phase of the productive power generation section of the power generation coil matches the phase of the magnetic pole boundary line of the FG magnetic pole, and the generated voltage at the effective power generation section is O, the two lead wires are FGIif.
It straddles the two f-poles with different polarities and has a phase difference of 360×m (degrees) in electrical angle. Therefore, the generated voltages in the two lead wires cancel each other out, so the FG signal output does not have any unevenness in period or amplitude, improving the detection accuracy of the rotational frequency and, by extension, the performance of the equipment. It has the characteristic that it is possible.

Further, according to the frequency generator according to the second invention, the annular connecting portion is arranged on the fixed substrate with front and back sides, and the generating coil and the signal output terminal are electrically connected at this connecting portion. By connecting it, it is possible to eliminate the radial extension part that contributes to power generation, and only the generated voltage signal in the spine effect power generation part is transmitted to the signal output terminal, so the pole and F with stable period and small amplitude fluctuation
By obtaining the G signal output, it becomes possible to improve the detection accuracy of the rotational frequency. Therefore, like the first invention, FG
Signal output has no unevenness in period or amplitude,
The feature is that it is possible to improve the detection accuracy of the rotational frequency and, by extension, the performance of the device.

Further, according to the frequency generator of the third invention, the rotating magnet rotates, and the innermost peripheral part of the effective power generation part of the power generation film and the innermost peripheral end of the magnetic pole boundary line of the rotating magnet rotate. By configuring the structure so that the effective power generation part of the power generation coil and the magnetic pole boundary line of the rotating magnet are not parallel when they are in the same phase, the power generation coil Since the phase shift of the generated voltage waveform in each effective power generation section is alleviated, the FG signal output to the signal output terminal has an extremely stable period and small amplitude fluctuation, improving the detection accuracy of the rotational frequency. It becomes possible to do so. Therefore, it has the characteristic that it becomes possible to improve the performance of the device.

Further, according to the frequency generator according to the fourth aspect of the invention, the power generation coil is arranged on the first plane part of the fixed substrate, and the circle made of a magnetic material is arranged concentrically with the power generation coil on the second plane part. By disposing an annular yoke plate and setting the inner diameter of the yoke plate to be larger than the diameter of the innermost circumference of the effective power generation part of the power generation coil, the center of the rotating magnet is aligned with the center of rotation of the shaft. Even when they do not match, the magnetic flux linking to the outer periphery of the effective power generation section of the power generation coil, which contributes the most to power generation, is focused on the yoke plate arranged concentrically with the power generation coil, so that each effective power generation section of the power generation coil is The phase shift and amplitude fluctuation of the generated voltage waveform are alleviated, and the FG signal output to the signal output terminal has an extremely stable period and small amplitude fluctuation, which improves the detection accuracy of the rotational frequency. It becomes possible. Therefore, it has the characteristic that it is possible to improve the performance of the equipment.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the FG section in one embodiment of the first and third inventions, FIG. 2 is a plan view of the fixed substrate and rotating magnet in the first embodiment of the first invention, and FIG. 3 4 is a plan view of the stationary substrate and rotating magnet in the second embodiment of the first invention, and FIG. Figure 5 is a plan view of the fixed substrate in the second invention viewed from the second plane part side where the generating coil is not disposed, and Figure 6 is a cross-sectional view of the FG part in the second invention. FIG. 7 is a plan view of the fixed substrate and rotating magnet in the third invention, FIG. 8 is a plan view when the rotating magnet and the power generating coil are not concentric with each other in the third invention, and FIG. 9 is a plan view of the fourth invention. 10 is a cross-sectional view of the FG portion in the fourth invention; FIG. 11 is a cross-sectional view when the rotating magnet is eccentric in the fourth invention; FIG. FIG. 12 is a cross-sectional view of the FG section in the conventional example, FIG. 13 is a plan view of the fixed substrate in the conventional example, and FIG. 14 is a plan view when the rotating magnet and the generating coil are not concentric with each other in the conventional example. FIG. 15 is a plan view of a rotating magnet, FIG. 16 is a plan view of a fixed substrate and rotating magnet in a conventional example, and FIG. 17 is a diagram showing the relationship between the rotation angle of the motor and the FG generation voltage in the conventional example. 24... Rotating magnet, 27... Effective power generation section, 28
...Generating coil, 40... Fixed board, 50...
・Through hole% 80a, 60b・
. . . Annular connection portion, 70a, 70b . . . Signal output terminal, 71a. 7lb...Leader line, 80...
Yoke plate, 124...Magnetic pole boundary line, 125...
FG magnetic pole. Name of agent: Patent attorney Shigetaka Kurino and one other person Figure 12 Figure 14 Figure 15! θ0

Claims (5)

[Claims] (1) A rotating magnet magnetized with 2n poles (n=2, 3,...) at equal pitches, a fixed substrate placed opposite to the magnetic pole surface of the rotating magnet, and a fixed substrate placed on the fixed substrate. a comb-shaped power generation coil provided thereon; and two signal output terminals provided on the fixed substrate on which the power generation coil is provided, on either the outer circumference side or the inner circumference side of the power generation coil. and two lead wires electrically connecting the signal output terminal and the power generation coil, each of the two lead wires having at least a radially extending portion, and the radially extending portion have substantially the same shape, and 360/n×m (degrees) (m
A frequency generator characterized by having a phase difference in the circumferential direction from each other by 1, 2, . . . (n-1). (2) The frequency generator according to claim 1, wherein the radially extending portion of the lead wire has a spiral shape. (3) a rotating magnet magnetized with multiple poles at an equal pitch, and a fixed substrate having a first plane part and a second plane part arranged opposite to the magnetic pole surface of the rotating magnet and having a front-back relationship with each other; a comb-shaped power generation coil disposed on a first plane portion of the fixed substrate; a through hole electrically connected to the starting end or terminal end of the power generation coil and disposed on the fixed substrate; The first and second signal output terminals respectively disposed on the first and second plane parts on the fixed substrate, and the first signal output terminal and the end or start end of the power generation coil are connected electrically. an annular first connection portion connected to the fixed substrate and arranged concentrically with the power generation coil on the first plane portion of the fixed substrate; and the second signal output terminal and the through hole. and an annular second connection part that is electrically connected to the hole and is disposed on a second plane part of the fixed substrate and concentrically with the power generation coil. frequency generator. (4) It is equipped with a rotating magnet magnetized with multiple poles at an equal pitch, a fixed substrate placed opposite to the magnetic pole surface of the rotating magnet, and a comb-shaped power generating coil arranged on the fixed substrate. Become,
When the rotating magnet rotates and the innermost circumferential end of the effective power generation portion of the generating coil and the innermost circumferential edge of the boundary line of the magnetic poles of the rotating magnet are in the same phase, A frequency generator characterized in that a phase of an outer peripheral end does not match a phase of an outermost peripheral end of a boundary line of magnetic poles of the rotating magnet. (5) A rotating magnet magnetized with multiple poles at an equal pitch, a fixed substrate placed opposite to the magnetic pole surface of the rotating magnet, and a comb-shaped power generator arranged on the first flat part of the fixed substrate. coil and
An annular yoke plate made of a magnetic material is provided on the second plane portion of the fixed substrate and is arranged concentrically with the power generation coil, and the inner diameter of the yoke plate is equal to the effective diameter of the power generation coil. A frequency generator characterized in that the diameter is larger than the diameter of the innermost circumference of the power generation section.