JP3269322B2 - Signal generator for internal combustion engine ignition system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal generator for an ignition device of an internal combustion engine, which uses a magnetic sensor to generate a signal used to determine the ignition timing of the internal combustion engine.

[0002]

2. Description of the Related Art Generally, an ignition device for an internal combustion engine is provided with a semiconductor switch for controlling a primary current on a primary side of an ignition coil, and the semiconductor switch is turned off or turned on or off by a predetermined ignition signal generated at the ignition timing of the internal combustion engine. The primary current of the ignition coil is suddenly changed by conducting the current, a high voltage is induced in the secondary coil of the ignition coil, and this high voltage is applied to a spark plug attached to a cylinder of the engine so as to fly a spark. I have.

In order to operate this type of ignition device,
It is necessary to attach a signal generator for generating a signal for determining the ignition timing to the internal combustion engine. A signal obtained from the signal generator may be directly supplied to a semiconductor switch as an ignition signal.When a signal obtained from the signal generator is supplied to an ignition timing controller to generate an ignition signal from the ignition timing controller. There is also. In any case,
In order to determine the ignition timing, a signal generator for generating a signal at a predetermined rotation angle position of the engine is required.

Various types of signal generators have been put into practical use, and one type using a magnetic sensor using a magnetically sensitive element such as a Hall element is known.

FIG. 11 shows an example of an ignition device using this type of signal generator. This ignition device is provided in a magnet generator that rotates synchronously with the engine, and the AC generator synchronizes with the rotation of the engine. An exciter coil EX for inducing a voltage, and an ignition coil IG having a primary coil L1 and a secondary coil L2
And an ignition energy storage capacitor C provided on the primary side of the ignition coil and charged through the rectifier D by the output of the exciter coil EX, and discharging the electric charge of the capacitor C to the primary coil L1 of the ignition coil when conducting. A thyristor Th as a semiconductor switch for controlling a primary current provided in the engine and a spark plug P attached to a cylinder of an engine (not shown) and connected to a secondary coil L2 of an ignition coil.
And a signal generating device SG, and an inverting circuit X for inverting the output of the signal generating device SG and applying the inverted signal to the thyristor Th as an ignition signal Vi.

[0006] The signal generator SG includes a rotor 1 having a reluctor 2 and a signal generator 3, and the rotor 1 is mounted on a rotating shaft of the engine. The signal generator 3 generates a signal voltage Vs by detecting a change in magnetic flux generated by the reluctor 2 of the rotor 1 by the magnetic sensor 7. In the illustrated example, the magnetic sensor 7 is formed of a Hall IC, and has a power terminal 7a, an output terminal 7b, and a ground terminal 7c,
An output voltage Vcc of a DC power supply (not shown) is applied between the power supply terminal 7a and the ground terminal 7c. The signal emitting device 3 of this example maintains a high level state when the reluctor 2 is not opposed to the magnetic pole portion of the signal emitting device 3 and has a low level when the reluctor 2 is opposed to the magnetic pole portion of the signal emitting device 3. To output a signal voltage Vs having a pulse waveform falling.

The inverting circuit X is composed of an NP having an emitter grounded.
An N-transistor Tr1, a resistor R1 connected between the collector of the transistor Tr1 and the positive terminal of a DC power supply (not shown), and a resistor R2 connected between the base of the transistor Tr1 and the output terminal 7b for signal emission. And outputs an ignition signal Vi that changes from a low level to a high level at the ignition timing by inverting the level of the signal voltage Vs.

In this ignition device, the output of the exciter coil EX charges the ignition energy storage capacitor C through the rectifier D to the polarity shown in the figure. When the signal generator 3 generates the signal voltage Vs at the ignition timing of the engine, the output inverting circuit X gives the thyristor Th an ignition signal Vi.
As a result, when the thyristor Th becomes conductive, the electric charge of the ignition energy storage capacitor C is changed to the primary coil L of the ignition coil.
1 through which a high voltage is induced in the secondary coil L2. Since this high voltage is applied to the spark plug P, a spark is generated in the spark plug and the engine is ignited.

FIG. 12 shows an example of the structure of a conventional signal generator using a magnetic sensor.
It has a structure in which a rotor 1 provided with a reluctor 2 on the outer periphery of a rotating body made of a magnetic material, and a signal generator 3 are provided.
The signal emission 3 is supported by an emission holder (not shown) made of a non-magnetic material.

The signal generator 3 includes a plate-shaped permanent magnet 4, a first magnetic pole piece 5 having one end coupled to one magnetic surface (N pole surface in the illustrated example) of the permanent magnet 4, A second pole piece 6 having one end coupled to the N pole face of the permanent magnet 4 and having a longer length than the first pole piece 5;
And a magnetic sensor 7 disposed between the magnetic pole piece 6 and
The other end of the first pole piece 5 and the other end of the second pole piece 6 are magnetic pole portions 5a and 6a facing the rotor 1.

The magnetic sensor 7 includes a first pole piece 5 and a second pole piece 5.
A magnetic field-sensitive Hall IC having a Hall element as a magnetically sensitive element having a pair of magnetic sensing surfaces respectively magnetically coupled to the pole pieces 6 of the pair, and having a center between the pair of magnetic sensing surfaces. The position is substantially aligned with the magnetic center position of the permanent magnet 4 with respect to the rotation direction of the rotor 1. A DC voltage of a constant voltage is applied to the input terminal of the Hall IC from a power supply (not shown), and one direction from one side of the pair of magnetic sensing surfaces of the Hall IC to the other side (the direction of arrow y in the drawing). When a magnetic flux having a magnetic flux density equal to or higher than a predetermined detection operation level flows (hereinafter, referred to as a detection direction), the Hall IC performs a detection operation and outputs an electric signal.

The signal generator 3 is fixed to a crankcase or the like of the internal combustion engine by a generator holder (not shown), and the magnetic pole portion 6a of the longer second magnetic pole piece 6 is minutely applied to the reluctor 2 of the rotor 1. They face each other via an air gap G.

In the state shown in FIG. 13A where the reluctor 2 does not face the magnetic pole portion 5a of the first magnetic pole piece 5 and the magnetic pole portion 6a of the second magnetic pole piece 6, the permanent magnet 4 Most of the generated magnetic flux is the N pole of the permanent magnet 4 → the side surface of the first pole piece 5 → the space → the path of the S pole of the permanent magnet 4 and the N pole of the permanent magnet 4 → the second Magnetic pole piece 6
Flow through the path of the side surface → space → S-pole of the permanent magnet 4 as the leakage magnetic fluxes φr1 and φr2, so that the magnetic flux hardly passes through the magnetic sensor 7. A part of the magnetic flux generated by the permanent magnet 4 flows through a part of the magnetic sensor 7, but the size of the permanent magnet 4, the first pole piece 5 and the second pole piece is exactly equal to the prescribed size, and the permanent magnet 4 Are arranged so that the center position of the magnetic sensor 7 exactly matches the magnetic center of the permanent magnet 4, the magnetic flux flowing through a part of the magnetic sensor 7 Since the magnetic flux flowing in the detection direction (the direction indicated by the solid line arrow in the drawing) and the magnetic flux flowing in the opposite direction are substantially equal, the magnetic flux φso (magnetic flux density Bso) flowing in the detection direction of the magnetic sensor 7 is almost zero.

The rotor 1 rotates in the direction of arrow H shown in the figure, and the reluctor 2 faces the magnetic pole portion 6a of the second magnetic pole piece 6 in FIG.
3B, the N pole of the permanent magnet 4 → the second pole piece 6 → the magnetic pole part 6a → the reluctor 2 → the side surface of the reluctor 2 and the rotor, as indicated by the broken line arrow in FIG. The magnetic flux φ in the path of the outer peripheral surface of the rotating body 1 → space → the S pole of the permanent magnet 4
b flows, and the N pole of the permanent magnet 4 → the first magnetic pole piece 5 → the magnetic sensor 7 → the second magnetic pole piece 6 → the magnetic pole portion 6a → the reluctor 2 → the side surface of the reluctor 2 and the outer periphery of the rotor of the rotor 1. The magnetic flux φsa flows through the path from the surface → the space → the S pole of the permanent magnet 4. Since the magnetic flux φsa (magnetic flux density Bsa) flows in the detection direction of the Hall IC, the magnetic sensor 72 outputs an electric signal.

FIG. 14A shows how the magnetic flux density Bs detected by the magnetic sensor 7 changes with the change of the rotation angle θ of the rotor 1. FIG. 14B shows a waveform of an electric signal output from the magnetic sensor (Hall IC) 7 according to the change in the magnetic flux density.

The magnetic flux density Bs rises while the magnetic flux in the detection direction (solid arrow y direction shown in FIG. 13) flows through the magnetic sensor 7, and the magnetic flux density Bs becomes a hole at the rotation angle position θ1 of the rotor 1. When the detection operation level of the IC reaches + Bt, the output Vs of the magnetic sensor becomes a low level (L level), and the magnetic flux density Bs at the rotation angle position θ2 becomes smaller
If the detection operation level of C is lower than + Bt, the output Vs of the magnetic sensor becomes a high level (H level). The output Vs of the magnetic sensor is inverted between its high level and low level by the output inverting circuit X shown in FIG. A high-level electric signal obtained by inverting the low-level output of the magnetic sensor is supplied to the primary current control semiconductor switch of the ignition circuit as an ignition signal. When the ignition signal reaches the trigger level of the thyristor Th of the ignition circuit at a predetermined rotational angle position θi (ignition timing), the thyristor Th conducts and the ignition operation is performed.

[0017]

In a conventional signal generator using a magnetic sensor, variations in the dimensions of the permanent magnet 4 and the pole pieces 5 and 6, variations in the sensitivity of the magnetically sensitive element, and If there is a variation in the magnetization distribution, even when the reluctor 2 is not opposed to the magnetic pole portion 6a of the second magnetic pole piece 6, the leakage magnetic flux flows in the detection direction through the magnetic sensing element, and the magnetic flux of the leakage magnetic flux The density may be equal to or higher than the detection operation level + Bt of the magnetically sensitive element. Due to the leakage magnetic flux, a noise signal may be generated at a position other than the predetermined rotation angle position, and the ignition device may malfunction.

It is an object of the present invention to always provide a signal at an accurate position without being affected by variations in dimensions of permanent magnets and pole pieces, variations in sensitivity of magnetically sensitive elements, and variations in magnetization distribution of permanent magnets. It is an object of the present invention to provide a signal generating device for an internal combustion engine ignition device which can generate the following.

[0019]

SUMMARY OF THE INVENTION The present invention comprises a rotor having a reluctor, a signal generator for detecting a change in magnetic flux generated by the reluctor by a magnetic sensor and outputting a signal, and igniting an internal combustion engine. In a signal generator for an internal combustion engine ignition device that generates a signal for determining the timing, without being affected by variations in the dimensions of magnets and pole pieces, variations in sensitivity of magnetic sensors, or variations in magnetization distribution of permanent magnets Thus, a signal can always be generated at an accurate position.

Therefore, in the signal generating apparatus according to the present invention, the above-mentioned signal-generating electron is converted into a permanent magnet and a magnetic pole portion having one longitudinal end coupled to one magnetic pole surface of the permanent magnet and the other end facing the rotor. First and second pole pieces,
And a magnetic sensor disposed between the first pole piece and the second pole piece, the first pole piece having a longitudinal dimension set to be smaller than the longitudinal dimension of the second pole piece. ing. The magnetic sensor has first and second magnetic sensing surfaces magnetically coupled to the first and second pole pieces, respectively, and includes one of the first and second magnetic sensing surfaces. A magnetic sensing element that performs a detecting operation when a magnetic flux having a magnetic flux density equal to or higher than a predetermined detecting operation level flows from one side to the other side, and a center between the first and second magnetic sensing surfaces of the magnetic sensor. The position is arranged so as to be located at a position closer to one side of the first magnetic pole than the magnetic center position of the permanent magnet. The first pole piece and the second pole piece are spaced from each other such that the respective magnetic pole portions face the rotor of the rotor with a predetermined phase difference.

As described above, in order to arrange the center position between the magnetic sensing surfaces of the magnetic sensors so as to be deviated toward the first pole piece side from the magnetic center position of the permanent magnet, for example, the rotation of the rotor The width dimension of the first pole piece measured in the direction may be set smaller than the width dimension measured in the rotation direction of the second pole piece.

[0022]

The length of the first pole piece is set shorter than the length of the second pole piece, and the magnetic sensor disposed between the first pole piece and the second pole piece has one pole piece side. As in the present invention, in a signal emission device which performs a detection operation when a magnetic flux having a magnetic flux density equal to or higher than the detection operation level flows in a direction (detection direction) toward the other magnetic pole half from the first magnetic sensor, as in the present invention,
And disposing the magnetic sensor in a state where the center position between the second magnetic sensing surface is deviated toward the first pole piece side from the magnetic center position of the permanent magnet, the magnetic pole portion of the second magnetic pole piece becomes In the opposed state, magnetic flux flows from the first pole piece side to the second pole piece side in the magnetic sensor as in the conventional case, but the magnetic pole portion of the second pole piece faces the reluctor. In the absence state, a magnetic flux flows through the magnetic sensor in a direction from the second pole piece to the first pole piece. Therefore, the directions of the magnetic flux flowing through the magnetic sensor are opposite to each other when the magnetic pole portion of the second magnetic pole piece faces the reluctor. Therefore, even if there is a variation in the dimensions of the permanent magnets and the pole pieces, or a variation in the magnetic flux distribution of the permanent magnet, the detection direction is set at a position other than the predetermined rotation angle range of the reluctor set to flow the magnetic flux in the detection direction to the magnetic sensor. Thus, it is possible to prevent a magnetic flux higher than the detection operation level from flowing, and it is possible to always generate a signal at an accurate position.

If the width of the first pole piece measured in the rotation direction of the rotor is set smaller than the width of the second pole piece measured in the rotation direction, the first pole piece and By selecting the width dimension of the second pole piece, the center position of the magnetic sensor can be accurately and easily located at a position deviated by a predetermined amount toward the first pole piece side from the magnetic center position of the permanent magnet.

[0024]

1 to 3 show an embodiment of a signal generator for an internal combustion engine ignition device according to the present invention. The same parts as those of the signal generator shown in FIG. 12 are denoted by the same reference numerals.

A signal generator for an internal combustion engine ignition device according to the present embodiment includes a rotor 1 having a reluctor 2, a signal generator 3 for outputting a signal in accordance with a change in magnetic flux generated by the reluctor 2, And an electron emission holder 8 (see FIG. 2) for supporting the signal emission 3.

The signal generator 3 includes a plate-shaped permanent magnet 4 and a first magnetic pole piece 5 having one end in the longitudinal direction coupled to one magnetic pole surface (N pole surface in this example) of the permanent magnet 4. A second pole piece 6 whose one end in the longitudinal direction is also coupled to the N pole face of the permanent magnet 4, and a magnetic sensor disposed between the first pole piece 5 and the second pole piece 6. 7 is provided. The other end of the first magnetic pole piece 5 and the other end of the second magnetic pole piece 6 are magnetic pole portions 5a, 6a facing the rotor 1, and the first magnetic pole piece 5, the second magnetic pole piece 6, Are the magnetic pole portions 5a, 6a
Are arranged at an interval so as to face the reluctor 2 of the rotor 1 with a predetermined phase difference. First pole piece 5
Is set to be shorter than the longitudinal dimension of the second pole piece 6. In the present embodiment, the longitudinal dimension of the first pole piece 5 is set smaller than the width dimension of the second pole piece 6 measured in the rotation direction of the rotor 1.

The magnetic sensor 7 includes a first pole piece 5 and a second pole piece 5.
Has first and second magnetic sensing surfaces 7a and 7b magnetically coupled to the magnetic pole piece 6, respectively, from one magnetic sensing surface (in this example, the first magnetic sensing surface 7a) side to the other magnetic sensing surface. A magnetic sensing element that performs a detecting operation when a magnetic flux having a magnetic flux density equal to or higher than a predetermined detecting operation level flows in one direction (a detecting direction) toward the surface (in this example, the second magnetic sensing surface 7b). This magnetic sensor has a one-sided magnetic field type Hall element having a predetermined sensitivity to a magnetic flux flowing in one direction, an amplifier for amplifying the output of the Hall element, and an output of the amplifier exceeding a predetermined level. It consists of an element (Hall IC) in which a conductive switch element and the like are integrated into an IC. A constant DC voltage is applied to the input terminal of the magnetic sensor 7 from a power supply (not shown), and when a magnetic flux in the detection direction flows through the Hall element of the magnetic sensor, an electric signal obtained from the output terminal is at a high level. From the state to the low level state.

In this embodiment, as described above, the width of the first pole piece 5 is set to be smaller than the width of the second pole piece 6, and the first pole piece 5 and the second pole piece 5 are connected to each other. The magnetic sensor 7 disposed between the magnetic pole piece 6 and the magnetic sensor 7 is positioned at the center position between the first and second magnetic sensing surfaces 7a and 7b (the position indicated by a chain line Ys in FIG. 1). Position (the center position in the width direction of the permanent magnet 4 measured in the rotation direction of the rotor 1,
(The position indicated by the dashed line Ym).

The signal generator 3 is supported by a generator holder, which will be described later, and in the process of rotating the rotor 1, the magnetic pole portion 6 a of the second magnetic pole piece 6 having a longer length than the first magnetic pole piece 5. Is positioned so as to face the reluctor 2 via the minute air gap G, and is fixed to a mounting portion provided on a crankcase or a cover of the engine.

As shown in FIG. 2, the generator holder 8 for supporting the signal generator 3 is formed of a non-magnetic material such as a synthetic resin. In the opened state, an emission-generating recess 8c for incorporating the signal emission 3 is provided, and a resin such as an epoxy resin is covered so as to cover the signal emission 3 housed in the emission-incorporation recess 8c. 9 are filled.

Both edges 8a and 8b of the electron generating holder 8 are formed in a flange shape, and the both edges 8a and 8b are provided with mounting holes 8d and 8e, respectively.
Using d and 8e, signal emission is fixed to a crankcase or the like of an internal combustion engine (not shown).

In this embodiment, as shown in FIG. 3, the rotor 1 has a rotating body 10 formed of a flywheel formed of a ferromagnetic material such as iron in a cup shape. A main permanent magnet 11 is attached to the inner periphery of the rotating body 10, and the rotating body 10 and the magnet 11 constitute a magnet rotor. The main stator 12 is arranged inside the magnet rotor. The stator 12 has a structure in which a power generating coil 14 is wound around each of a plurality of salient pole portions 13a on the outer periphery of a stator iron core 13.

When the cup-shaped flywheel is used as the rotating body 10 as described above, the reluctor 2 can be formed by projecting a part of the peripheral wall portion to the outside. The circumferential length of the reluctor 2 is set to a predetermined value.

In the signal generator having the above-described structure, the figure shows that the reluctor 2 of the rotor 1 does not face the magnetic pole portion 5a of the first magnetic pole piece 5 and the magnetic pole portion 6a of the second magnetic pole piece 6 of the signal generator 3. In the state shown in FIG. 4 (A), the magnetic flux generated by the permanent magnet 4 changes from the N pole of the permanent magnet 4 to the arrow shown by the broken line arrow in FIG.
Side surface of first pole piece 5 → space → path of S pole of permanent magnet 4 and N pole of permanent magnet 4 → side surface of second pole piece 6 → space →
Leakage fluxes φr1 and φr2 flow through the S pole path of the permanent magnet 4. Since the magnetic sensor 7 is biased toward the first pole piece 5 side, in this state, the N pole of the permanent magnet 4 → the magnetic sensor 7 → the side surface of the first pole piece 5 → the space → the permanent magnet 4
The magnetic flux φsb passing through the magnetic sensor 7 flows through the S-pole path.
The magnetic flux φsb is directed from the second pole piece 6 to the first pole piece 5 (the direction opposite to the detection direction of the magnetic sensor 7).
With the magnetic flux density Bsb.

When the rotor 1 rotates in the direction of the solid arrow shown in the figure and the reluctor 2 is brought into the state shown in FIG. 4B in which it faces the magnetic pole portion 6a of the second magnetic pole piece 6, FIG. In addition to the leakage magnetic fluxes φr1 and φr2 flowing along the same path as shown, the N pole of the permanent magnet 4 → the second pole piece 6 → the magnetic pole portion 6a → the reluctor 2 → the side surface of the reluctor 2 and the rotating body of the rotor 1. The magnetic flux φb flows in the path of the outer peripheral surface of 10 → space → the S pole of the permanent magnet 4, and further the N pole of the permanent magnet 4 → the magnetic sensor 7 → the second magnetic pole piece 6 → the magnetic pole part 6a → the reluctor 2 → the reluctor 2 Side surface and outer peripheral surface of rotor 10 of rotor 1 → space → S of permanent magnet 4
The magnetic flux φsa flows through the pole path. The magnetic flux φsa flows in the direction from the first pole piece 5 side to the second pole piece 6 side, and the magnetic flux φsa causes the magnetic sensing element of the magnetic sensor 7 to generate a magnetic flux (in the direction indicated by the solid arrow y in the drawing) in the magnetic sensing element. The magnetic flux density Bsa) flows.

FIG. 5A shows how the magnetic flux density Bs detected by the magnetic sensor 7 changes as the rotation angle θ of the rotor 1 changes. FIG. 5B shows a waveform of an electric signal output from the magnetic sensor (Hall IC) 7 according to the change of the magnetic flux density.

The magnetic pole portion 6a of the second magnetic pole piece 6 is
When the magnetic pole part 6a starts to face the reluctor from the state where the magnetic flux (magnetic flux density Bsb) in the direction opposite to the detection direction is flowing to the magnetic sensor 7 without being opposed to the magnetic sensor 7,
When the direction of the magnetic flux flowing through the rotor 1 is reversed and its magnetic flux density Bs rises, and the rotor 1 reaches a predetermined rotational angle position θ1, the magnetic flux density Bs becomes equal to the detection operation level +
Bt is reached. Thereby, the magnetic sensor (Hall IC)
7, the output Vs changes to a low level (L level). As the rotor 1 further rotates and the facing area between the magnetic pole portion 6a of the second pole piece 6 and the reluctor 2 decreases, the magnetic flux density detected by the magnetic sensor decreases, and at the rotation angle position θ2 When the magnetic flux density Bs becomes smaller than the detection operation level + Bt, the output Vs of the magnetic sensor 7 becomes high (H level).
Changes to The output Vs of the magnetic sensor 7 is inverted by the output inverting circuit X shown in FIG. 11, and a high-level electric signal (a signal rising at the angle θ1) obtained by inverting the low-level output of the magnetic sensor 7 is obtained. Is supplied to the primary current control semiconductor switch of the ignition circuit as an ignition signal. As a result, the thyristor Th conducts, and the ignition operation is performed.

In the above-described embodiment, the magnetic sensor 7 uses the direction from the first magnetic pole piece 5 side to the second magnetic pole piece 6 side as a detection direction, and sets a magnetic flux higher than a predetermined detection operation level in this detection direction. Although a one-sided magnetic field type Hall IC that performs a detection operation when a magnetic flux of a high density flows is used, the magnetic sensor 7 has a predetermined shape in a direction from the second pole piece 6 side to the first pole piece 5 side. A one-sided magnetic field type Hall IC that performs a detection operation when a magnetic flux having a magnetic flux density equal to or higher than the detection operation level flows may be used. FIGS. 6A and 6B show the flow of magnetic flux when such a Hall IC is used as the magnetic sensor 7. In these figures, the direction of the solid arrow y 'indicates the detection direction of the magnetic sensor, and FIG.
The detection direction of the magnetic sensor 7 is opposite to the example shown in FIG.

FIG. 7A shows the magnetic flux density Bs detected by the magnetic sensor 7 in the case shown in FIGS. 6A and 6B.
Shows the state of change with the change of the rotation angle θ of the rotor 1. In FIG. 3, the detection direction of the magnetic sensor 7 is shown on the positive side (upper side of the base line). The waveform in FIG. 7A corresponds to the waveform shown in FIG. 5A inverted upside down. FIG. 7B shows the magnetic flux density Bs of FIG.
3 shows a waveform of an electric signal output from the magnetic sensor 7 in accordance with the change of.

In this example, the reluctor 2 has the second pole piece 6
Since the output Vs of the magnetic sensor 7 is at a high level (H level) when it is opposed to the magnetic pole portion 6a of the ignition circuit, the output Vs of the ignition circuit can be controlled without inverting the high-level electric signal.
It can be supplied to the secondary current control semiconductor element as an ignition signal.

In the above embodiment, the width dimension of the first pole piece 5 measured in the rotation direction of the rotor 1 is set smaller than the width dimension of the second pole piece 6 similarly measured in the rotation direction. The total dimension of the width of the magnetic pole pieces 5 and 6 and the width of the magnetic sensor 7 measured in the rotation direction is also equal to the width of the magnetic sensor 7 measured in the rotation direction. The width dimension of each of the first pole piece 5 and the second pole piece 6 is selected, and the outer surfaces of both pole pieces in the rotational direction are aligned with the side surfaces on both sides of the permanent magnet 4 in the rotational direction. With this configuration, the center position of the magnetic sensor 7 is set to be more than the magnetic center position of the permanent magnet 4 in the rotation direction.
Can be accurately biased on the side of the pole piece 5 by a fixed amount (a half of the difference between the width dimension of the second pole piece and the width dimension of the first pole piece).

However, in order to bias the center position of the magnetic sensor 7 (center position between the first and second magnetic sensing surfaces) toward the first pole piece 5 side from the magnetic center position of the permanent magnet 4, The position of the outer surface of each of the first pole piece 5 and the second pole piece 6 is matched with the position of the side surface on both sides of the permanent magnet 4, and the width of the first pole piece 5 is changed to the second pole. It is not always necessary to set the width smaller than the width of the piece 6. For example, as shown in FIGS. 8 and 9, the total dimension of the width dimension of the first pole piece 5 and the second pole piece 6 and the width dimension of the magnetic sensor 7 is different from the width dimension of the permanent magnet 4. , Or as shown in FIG.
Even when the width of the pole piece 5 and the width of the second pole piece 6 are set to be substantially equal, the center position of the magnetic sensor 7 (the position of the dashed line Ys in the drawing) is set to the magnetic center position of the permanent magnet 4 (the drawing (Indicated by the dashed line Ym) from the first magnetic pole piece 5 side, and in these cases as well, the retractor 2 is in a state where it faces the magnetic pole portion 6a of the second magnetic pole piece 6. The direction of the magnetic flux flowing through the magnetic sensor 7 can be reversed between the time and when the reluctor 2 is not facing the magnetic pole portion 6a.

In the above embodiment, one of the pole faces of the permanent magnet 4 to which one end in the longitudinal direction of each of the first pole piece 5 and the second pole piece 6 is connected is the N pole face. One of the pole faces may be an S pole face. In this case, the direction of the magnetic flux flowing through the magnetic sensor 7 is opposite to the direction when the one magnetic pole surface is set to the N pole surface.

As described above, in each of the above embodiments, the state where the magnetic pole portion 6a of the second magnetic pole piece 6 faces the reluctor 2 and the state where the magnetic pole portion 6a does not face the reluctor 2 are described. Sometimes, the directions of the magnetic flux flowing through the magnetic sensor 7 are opposite to each other. Therefore, when the relative position in the rotational direction between the magnetic pole portion 6a of the second magnetic pole piece 6 and the reluctor 2 is outside the range in which the magnetic flux in the detection direction flows to the magnetic sensor 7, the permanent magnet or the magnetic pole Even if there is a variation in the size of the piece, a variation in the sensitivity of the magnetically sensitive element, or a variation in the magnetic flux distribution of the permanent magnet, a magnetic flux having a magnetic flux density higher than the detection operation level may flow in the detection direction of the magnetic sensor 7. Therefore, there is no possibility that a noise signal is generated by the leakage magnetic flux.

[0045]

As described above, according to the present invention, the longitudinal dimension of the first pole piece is set smaller than the longitudinal dimension of the second pole piece, and the first pole piece is disposed between the two pole pieces. Since the center position of the magnetic sensor is biased toward the first magnetic pole side from the magnetic center position of the permanent magnet, even if there is a variation in the dimensions of each part or a variation in the sensitivity of the magnetic sensor, the magnetic sensor does not malfunction, The signal can always be generated at the correct position. For this reason, there is an advantage that the management of the dimensional accuracy of each component can be made coarser than in the past and the cost can be reduced.

In the present invention, when the width dimension of the first pole piece is set smaller than the width dimension of the second pole piece, the width dimension of both pole pieces is appropriately selected so that the magnetic sensor can be used. The center position of the first magnet from the magnetic center position of the permanent magnet.
Can easily and accurately be biased by a desired amount toward one side of the magnetic pole, thereby facilitating the assembly of signal emission.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the relationship between signal emission, a rotor, and a reluctor in one embodiment of the present invention.

FIG. 2 is a rear view showing a state in which signal emission used in one embodiment of the present invention is incorporated in an emission holder.

FIG. 3 is a vertical sectional view of an essential part showing an example of a state in which the signal generator and the magnet generator according to the embodiment of the present invention are combined.

FIGS. 4A and 4B are explanatory diagrams showing a positional relationship between signal emission and a reluctor in one embodiment of the present invention.

FIG. 5 is a diagram showing a change in magnetic flux density of the magnetic sensor and a waveform of an output signal of the magnetic sensor in the embodiment of FIG. 1;

FIGS. 6A and 6B are explanatory diagrams showing a positional relationship between signal emission and a reluctor in another embodiment of the present invention.

FIG. 7 is a diagram showing a change in magnetic flux density of the magnetic sensor and a waveform of an output signal of the magnetic sensor in the embodiment of FIG. 6;

FIG. 8 is an explanatory diagram showing a modification of the arrangement when the magnetic sensor is arranged so as to be biased to the first magnetic pole piece side in the signal generator of the present invention.

FIG. 9 is an explanatory view showing another modification of the arrangement when the magnetic sensor is arranged to be biased toward the first magnetic pole piece side in the signal generating device of the present invention.

FIG. 10 is an explanatory diagram showing still another modified example of the arrangement method when the magnetic sensor is arranged so as to be biased to the first magnetic pole piece side in the signal generating device of the present invention.

FIG. 11 is a circuit diagram showing an example of a state in which a signal generator for generating an ignition signal using a magnetic sensor is combined with an ignition circuit for a capacitor discharge internal combustion engine.

FIG. 12 is a perspective view showing a structural example of a conventional signal generator for an internal combustion engine ignition device.

FIGS. 13A and 13B are explanatory diagrams showing a positional relationship between signal emission and a reluctor in a conventional signal generator.

FIG. 14 is a diagram showing a change in magnetic flux density of the magnetic sensor shown in FIG. 13 and a waveform of an output signal of the magnetic sensor.

[Explanation of symbols]

 EX Exciter coil D Rectifier C Ignition energy storage capacitor L1 Ignition coil primary coil L2 Ignition coil secondary coil P Spark plug Th Thyristor X Output inverting circuit G Air gap 1 Rotor 2 Reluctor 3 Signal generation 4 Permanent magnet 5 First magnetic pole piece 5a Magnetic pole part 6 Second magnetic pole piece 6a Magnetic pole part 7 Magnetic sensor 8 Electrogenic holder 9 Resin 10 Rotating body 11 Main permanent magnet 12 Main stator 13 Stator core 14 Power generation coil

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02P ^7/ 067-7/07 H02K 21/00

Claims (2)

(57) [Claims] 1. A rotor having a reluctor, a signal generator for detecting a change in magnetic flux generated by the reluctor and outputting a signal, wherein the signal generator has a permanent magnet and one end in a longitudinal direction. First and second magnetic pole pieces coupled to one magnetic pole surface of the permanent magnet and having the other end as a magnetic pole portion facing the rotor;
A magnetic sensor disposed between the first pole piece and the second pole piece, wherein a longitudinal dimension of the first pole piece is set smaller than a longitudinal dimension of the second pole piece. Wherein the magnetic sensor has a first magnetic sensing surface and a second magnetic sensing surface magnetically coupled to the first magnetic pole piece and the second magnetic pole piece, respectively. A magnetic sensing element that performs a detecting operation when a magnetic flux having a magnetic flux density equal to or higher than a predetermined detecting operation level flows from one side to the other side of the magnetic sensing surface of the second magnetic sensing surface; The magnetic pole pieces are spaced apart such that each magnetic pole portion faces the rotor of the rotor with a predetermined phase difference, and the magnetic sensor sets the center position between the first and second magnetic sensing surfaces as the magnetic pole piece. A state in which the magnetic center of the permanent magnet is biased toward one side of the first magnetic pole. A signal generating device for an internal combustion engine ignition device, wherein the signal generating device is arranged in a state. 2. A rotor having a reluctor, and a signal generator for detecting a change in magnetic flux generated by the reluctor and outputting a signal, wherein the signal generator has a permanent magnet and one end in a longitudinal direction. First and second magnetic pole pieces coupled to one magnetic pole surface of the permanent magnet and having the other end as a magnetic pole portion facing the rotor;
A magnetic sensor disposed between the first pole piece and the second pole piece, wherein a longitudinal dimension of the first pole piece is set smaller than a longitudinal dimension of the second pole piece. Wherein the magnetic sensor has first and second magnetic sensing surfaces magnetically coupled to the first and second pole pieces, respectively. A magnetic sensitive element that performs a detecting operation when a magnetic flux having a magnetic flux density equal to or higher than a predetermined detecting operation level flows from one side to the other side of the first magnetic pole piece, and the first magnetic pole piece and the second magnetic pole piece A magnetic pole portion is spaced apart from the rotor of the rotor with a predetermined phase difference, and a center position between the first and second magnetic sensing surfaces of the magnetic sensor is a magnetic center of the permanent magnet. Position it closer to the first pole piece than the position. The width of the first pole piece measured in the rotation direction of the rotor is set to be smaller than the width of the first pole piece measured in the rotation direction of the second pole piece. Signal generator.