JP2001069739A - Default opening degree stabilizing device for torque motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize stabilization by reinforcing a holding force to a default opening degree when an electromagnetic coil is not energized. SOLUTION: In a torque motor wherein a rotor 3 and at least one magnets motive force source 12 are integrated via a magnetic path, the N-pole and S-pole magnetized in the opposite directions and integrated or separate magnets 4-1, 4-2 are provided on the circumference edge of the rotor and three magnetic pole pieces 6, 7, 8 are provided on the circumference edge of an aperture where the rotor is provided and the two adjacent magnetic pole pieces are respectively coupled with coupling paths 9, 10, 11, an externally projected portions are asymmetrically provided at the circumference edge of the aperture and the length of magnets 4-1, 4-2 is extended longer than the points A, B of the starting and ending points of the projected portion to the external side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an electronically controlled throttle of an internal combustion engine, and is used to stably maintain a throttle opening at a predetermined position when a coil of the electronically controlled throttle is not energized. Device.

[0002]

2. Description of the Related Art An internal combustion engine, especially an automobile engine, is required to rotate, for example, a rotor of a torque motor in accordance with an amount of depression of an accelerator pedal, and to open and close a throttle valve that operates integrally with the rotor. It is designed to inhale a large amount of air.

[0003] Because of the above-mentioned operation principle, even when the electromagnetic coil of the torque motor is de-energized due to a failure, the necessary minimum opening of the throttle valve (hereinafter referred to as a default opening). ) Must be secured. The reason is that even when the electromagnetic coil is not energized,
This is because emergency avoidance driving must be guaranteed.

As a solution of this kind, various methods have already been proposed, and the applicant of the present invention is, for example, Japanese Patent Application No. Hei 10-173913 (hereinafter referred to as a prior application).
In this prior application, a mechanical spring is omitted by utilizing a reaction force of a magnetic spring when an electromagnetic coil is not energized.

The outline of the prior application will be described below with reference to FIG. First, FIG. 5A is a diagram showing the overall configuration.
(B) is a state diagram of the magnetic circuit when the electromagnetic coil is de-energized, and FIG.
(C) is a state diagram of the magnetic circuit when the electromagnetic coil is energized.

In FIG. 5 (a), reference numeral 1 denotes a torque motor main body, and a rotor 3 is rotatably provided inside a main air gap 2, and the rotor 3 rotates integrally with a shaft (not shown). A moving throttle valve is provided.

[0007] Then the main air gap 2 has a circular leading to B position radius l ₄ in clockwise with respect to the A position, in the radial l ₅ further from the position B to the position A, l _5> l ₄ Have a relationship. That is, from the B position clockwise until A position (referred to as large became part of the convex portion space toward the outside) to l ₅ -l ₄ = Δl only have large shape of the opening radius.

On the other hand, the rotor 3 reaches the position B at radius l ₂ in clockwise from the position A, decrease becomes radius l ₁ further from the position B to position A, have a relation of l _2> l ₁ (A portion recessed inward by l ₂ -l ₁ is referred to as a concave portion). 4-1 is a magnet magnetized to the N pole, 4-
Reference numeral 2 denotes a magnet magnetized to the S pole, which is fixed to the peripheral surface of the rotor 3. Each of the radii is l ₅ > l ₄ > l ₃ > l ₂ >
have a relationship of l _1.

Therefore, the space 5 where the rotor does not exist counterclockwise to the position B with respect to the position A is a portion having a radius of l ₅ -l ₁ . The space 5 is asymmetric (shifted) with respect to a center line (not shown) passing through the point O, and the right side has a larger area than the left side. The reason will be described later. This means that the magnet 4-1 (N
This means that the length of the portion facing the pole is large, and the length of the portion facing the magnet 4-2 (S pole) is small on the pole piece 7 side.

Reference numerals 6, 7, and 8 denote magnetic pole pieces. Therefore, a part of the magnet 4-1 and a part of the magnet 4-2 face the magnetic pole piece 6, and the magnetic pole piece 7 has a part of the magnet 4-1. But,
A part of the magnet 4-2 is opposed to the pole piece 8. Reference numerals 9, 10, and 11 are connecting magnetic paths. Reference numeral 12 denotes an electromagnetic coil as a magnetomotive force source, which is wound via a bobbin 13.

The operation will be described with reference to FIG. First, when the current of the electromagnetic coil 12 is 0 (when the coil 12 is not energized), the magnetic flux from the N pole of the magnet directly reaches the S pole in the pole piece 6 and the magnetic flux from the N pole of the magnet in the pole piece 7. The magnetic flux from the N pole of the pole piece 7 also reaches the S pole of the pole piece 6 via the connecting magnetic path 9 while reaching the magnet S pole facing the pole piece 8 via the connecting magnetic path 11.

In this state, since the interval of the main air gap is the smallest at l ₄ -l ₃ on each magnet side, the state becomes stable and the rotor stops at the illustrated position. In this case, the area 5 of the space 5 is the largest because the convex portion 14 on the outside of the main air gap and the concave portion 15 on the inside of the rotor 3 are aligned at the positions A and B, respectively.

As for the pole pieces, the two pole pieces 7 and 8 provided at both ends of the operating range of the rotor 3 have different lengths of the portions facing the rotor as described above. That is, the side 7 is longer and the side 8 is shorter. This inclination angle θ is the default opening.

The case where the electromagnetic coil 12 is energized will be described with reference to FIG. When the coil 12 is energized, FIG.
A magnetic flux as shown by the solid line arrow in (c) is generated, and the illustrated magnetic pole is generated on one side of each magnetic pole. That is, the pole piece 7 has S
A pole is generated, and an attractive force is generated with the N pole of the magnet 4-1. An S pole is generated on the pole piece 8, and the magnet 4-2
And the repulsive force is generated. Further, an N pole is generated on the pole piece 6, and an attractive force is generated with the S pole of the magnet 4-2. As a whole, the rotor 3 is rotated in the direction of arrow A in the figure.
Here, when the direction of current is reversed, the polarity of the pole piece is reversed,
A reverse torque is generated.

Next, let us consider a case where the current value becomes 0 due to a failure while a current of a predetermined value is flowing through the electromagnetic coil 12. In this case, since the magnetomotive force source by the electromagnetic coil 12 has disappeared, only the magnet magnetomotive force source by the rotor 3 is used.

Therefore, the rotor 3 which has been rotated in the direction of the solid arrow to a predetermined angle corresponding to the current value returns to the direction of the dotted arrow, but the ends of the magnets 4-2 of the rotor are at the A and B positions, respectively. If it matches, stop at this position. The reason is, as already described, the magnet 4 of the rotor 3.
2 continues clockwise further beyond the B position, the rotor 3
This is because the width of the air gap between the magnet 4-2 provided in the above and the convex portion protruding outside the main air gap 2 becomes large, and the magnetic resistance (reluctance) becomes large. Therefore, when the current of the electromagnetic coil becomes zero, it stops at the default opening position. That is, the default opening position θ is always maintained.

[0017]

According to the above-mentioned prior art, the default opening θ can be set by the space 5 (hereinafter referred to as a default opening adjusting groove). This is because the magnetic flux tends to pass through a yoke having a high magnetic permeability and a gap as narrow as possible. That is, when the magnet is displaced from the default opening, the magnetic flux leaking into the default opening adjusting groove 5 becomes magnetic energy due to the above-described properties. Then, the magnetic energy becomes a rotational force (torque) for returning to the default opening, and the variation of the default opening is determined by the magnitude of the rotating force.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and provides a device for stabilizing a default opening of a torque motor having no variation by enhancing a holding force to a default opening when an electromagnetic coil is not energized. It is intended to be.

[0019]

According to a first aspect of the present invention, there is provided a default opening stabilizing device for a torque motor, wherein a rotatable rotor and at least one magnetomotive force source are integrated via a magnetic path. The rotor is provided with an N-pole and an S-pole magnetized in opposite directions integrally or separately on the periphery of the rotor, and at the periphery of the opening where the rotor is disposed. In a torque motor in which three magnetic pole pieces are provided and two magnetic pole pieces adjacent to each other are connected to each other by a connection passage, the length of the magnet is extended from the start and end points A and B of the outward convex portion. The configuration was provided. With this configuration, the rotational force returning to the default opening increases, and as a result, the holding force of the default opening is stabilized.

According to a second aspect of the present invention, in the first aspect of the present invention, in the first aspect, the ratio (m / n) of the magnet angle m to the magnetic pole angle n of the torque motor is changed. It was configured as follows. With such a configuration, the rotational force for returning to the default opening can be increased or decreased.

[0021]

FIG. 1 is a block diagram showing an embodiment of a default opening stabilizing device for a torque motor according to the present invention. In FIG. 1, the same parts as those in FIG. In the present embodiment,
The feature of the configuration in comparison with FIG.
The length of 1,4-2 is made to protrude from the positions of points A and B, and the protruding length is set to the same amount 1 on the N-pole and S-pole sides, and this portion is 4-1-1,4- Shown as 2-1. Other configurations are the same as those in FIG.

When the relationship between the length l of the protrusion of the magnet from the positions A and B of the magnet and the positions A and B is represented by an angle, the angle straddling the entire length of the two magnets is m. The angle (angle between magnetic poles) straddling the entire length between
Then, it was confirmed that by changing the ratio m / n of the magnet angle m to the magnetic pole angle n of the motor, the rotational force for returning to the default opening increased or decreased.

First, the overall operation is the same as that of FIG. 5 except for the operation of the protrusion length l of the magnet. That is, FIG.
5B, when the current of the electromagnetic coil 12 is 0 (when the electromagnetic coil 12 is not energized), the rotor 3 holds the default opening θ as described with reference to FIG. 5B. In this case, FIG.
The difference from (b) is that the holding force at the default position is larger than that in the case of FIG. 5, which is a feature of the present invention. Projection length l.

The operation of the projection length l of the magnet will be described below with reference to FIG. FIG. 2 is an enlarged view of the point A position. If the length of the magnet 4-1 is up to the point A, it is the same as that of the prior application, and the magnetic flux emitted from the magnet N pole enters the pole piece 7 at a substantially right angle. This is because the energy is the least, and the destination is the S pole magnet on the other side.

Next, the protruding length l will be described. in this case,
In the vicinity of the point A, the magnetic flux from the N pole of the magnet first passes obliquely in search of a short portion, but gradually becomes almost perpendicular and proceeds toward the S-polarity magnet. In short, the rotational force generated by the protruding length l portion is applied clockwise, and acts as a restoring force for further returning the rotor 3 to the original position.

On the other hand, the operation of the protruding length l portion at the point B position has the same operation as that of the point A position. In this case, a detailed description is omitted, but the rotation force is counterclockwise. Therefore, FIG.
When the electromagnetic coil shown in FIG. 1B is in the non-excited state, the two restoring forces due to the respective projecting lengths l are balanced, and the default opening θ shown in FIG. 1B is maintained.

FIG. 3 is a characteristic diagram showing the torque with respect to the operating angle of the rotor when the electromagnetic coil is not energized. The horizontal axis shows the operating angle [deg], and the vertical axis shows the torque [kgfcm].
The point at which the torque becomes 0 with respect to the rotation angle θ is the default opening. The characteristic of the present invention shown by the solid line is larger than the characteristic of the conventional device shown by the dashed line, because the torque gradient near the default opening is large. You can see that there is.

As described above, the restoring forces generated in the opposite directions (clockwise and counterclockwise) are balanced by the protrusion lengths l at the points A and B, respectively, as described above. Then, the torque to return to the default opening can be expressed as a torque change (hereinafter, referred to as a torque gradient) with respect to the rotation angle near the default opening.

FIG. 4 is a diagram showing the relationship between the torque gradient for returning to the default opening and m / n. In FIG. 4, m / n is plotted on the horizontal axis, and the torque gradient [kgfcm / de] is plotted on the vertical axis.
g]. As shown in FIG.
It can be seen that as n increases, the torque gradient also increases.

This means that as the protrusion length l of the magnet increases, the torque gradient increases, that is, the gradient of the broken line in FIG. 3 rises. In short, when the torque gradient increases, the rotational force that attempts to return to the default opening increases, which means that the dispersion of the default opening is reduced and a stable default opening can be maintained.

Although the above operation has been described with reference to FIGS. 1A and 1B, the operation of FIG. 1C is exactly the same as that of FIG. The reason for this is, as described above, that the present invention aims at increasing the holding force of the default opening degree θ (increasing the restoring force), and the operation itself is the same as the conventional example.

[0032]

As described above, according to the present invention, since the ratio (m / n) of the magnet angle m to the magnetic pole angle n of the torque motor is changed, the torque gradient near the default opening increases. As a result, the rotational force for returning to the default opening increases, and the default opening is stabilized, whereby a highly reliable default opening stabilizing device can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a default opening stabilization device for a torque motor according to the present invention.

FIG. 2 is a view for explaining the function and effect of a protrusion length l of a magnet.

FIG. 3 is a torque characteristic diagram with respect to an operating angle of a rotor when an electromagnetic coil is not energized.

FIG. 4 shows a torque gradient for returning to a default opening;
Ratio of magnet angle m to motor magnetic pole angle n (m
/ N).

FIG. 5 is a diagram showing the configuration and operation principle of the prior application.

[Description of Signs] 1 Torque motor main body 2 Main air gap 3 Rotor 4 Magnet 5 Space 6,7,8, Magnetic pole pieces 9,10,11 Connecting magnetic path 12 Magnetomotive force source 13 Bobbin 14 Convex part 15 Concave part

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tetsuro Ren 2480 Kuno, Odawara-shi, Kanagawa F-term in Mikuni Odawara Works (reference) 3G065 CA00 CA34 CA38 DA05 KA02

Claims (2)

[Claims] 1. A rotatable rotor and at least one magnetomotive force source are integrally assembled via a magnetic path, and the rotor has N pole and S pole magnetized in opposite directions integrally or A separate magnet is provided on the periphery of the rotor, and three pole pieces are provided on the periphery of the opening where the rotor is provided, and two adjacent pole pieces are connected to each other by a connection passage in a torque motor. An outwardly projecting portion is provided asymmetrically on the periphery of the opening, and the length of each of the magnets is provided to be longer than the starting and ending points A and B of the outwardly projecting portion. Default opening stabilization device for torque motor. 2. The stabilizing device for a default opening of a torque motor according to claim 1, wherein a magnetic pole angle n of the torque motor is set.
A default opening stabilizing device for a torque motor, characterized in that the rotational force for returning to the default opening is increased or decreased by changing the ratio (m / n) of the magnet angle m to the default opening.