JP3175385B2 - Hall effect type sensor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Hall effect type sensor device which can be preferably used for detecting a rotation angle in an ignition timing control device for an internal combustion engine.

[0002]

2. Description of the Related Art FIG. 6 is a sectional view showing a main part when a conventional Hall effect type sensor device is used for controlling the ignition timing of an internal combustion engine. Is a rotating shaft, and 3 is a magnetic flux shutter made of a magnetic material, which is fixed to the rotating shaft 2 so as to rotate integrally with the rotating shaft 2. Reference numeral 4 denotes a shutter unit provided at the tip of the magnetic flux shutter 3 as shown in FIG.
Are formed by notching a predetermined number of magnetic materials at equal intervals along the circumferential direction.

[0005] Reference numeral 5 denotes a magnet, 6 denotes a magnetic flux guide, 7 denotes a Hall effect element, which is disposed in a magnetic path formed by the magnet 5 and the magnetic flux guide 6. It is configured to move. Reference numeral 8 denotes a mold frame for integrally connecting the magnet 5, the magnetic flux guide 6, and the Hall effect element 7, and these constitute a Hall effect sensor device.

[0004] The operation of the Hall effect type sensor device configured as described above will be described below.

In the above configuration, when the rotating shaft 2 is rotated by the rotation of the engine, the magnetic flux shutter 3 integrally fixed thereto is also rotated, and the shutter portion 4 at the tip moves in the magnetic circuit including the Hall effect element 7. I do. Since the shutter portion 4 is formed in a notch shape, the magnetic flux in the magnetic circuit changes according to the rotation of the rotating shaft 2, and the Hall effect element 7 converts the change in the magnetic flux into an electric signal, and outputs the output signal. Is processed by a processing circuit (not shown) to detect the rotation angle of the rotating shaft 2 and control the ignition timing.

[0006]

In such a conventional Hall effect sensor device, it is difficult to produce a large magnetomotive force because the length of the magnet in the magnetizing direction is limited by the limitation of the space in the axial direction. In many cases, another closed magnetic circuit is formed between the magnetic flux guide on the magnet side and the magnet, and the magnetic path is short-circuited, so that the magnetic flux hardly flows to the opposing Hall effect element side. For this reason, it has been difficult to provide a sufficient magnetic force margin for operating the Hall effect element even if a temperature change or durability deterioration occurs. Therefore, when used in an internal combustion engine, there is a problem in reliability.

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention makes it easy and reliable to provide a sufficient magnetic force margin for operating the Hall effect element even with temperature changes and durability deterioration. It is an object of the present invention to provide a Hall effect type sensor device having high performance.

[0008]

In order to solve the above-mentioned problems, the present invention arranges magnets such that the radial direction of the magnetic flux shutter and the magnetizing direction are parallel to each other, and has both ends of the magnet having a width and a depth greater than those of the magnets. A magnetic-collecting yoke having a narrow magnetic plate mounted thereon and opposed to one of the magnetic plates with a space between the magnetic-collecting yoke and a Hall-effect element arranged below the magnetic-collecting yoke and wider than the magnetic-sensitive area of the Hall-effect element A projection having an area is provided, and the projection is disposed below the magneto-sensitive element, and the other end is opposed to the other side of the magnetic plate with a space therebetween.

[0009]

According to the present invention, the space restriction in the radial direction of the magnetic flux shutter is less strict than that in the axial direction due to the above configuration.
By making the magnetization direction coincide with that direction, the length in the magnetization direction can be increased. Therefore, the magnetomotive force can be increased. This also eliminates the need for the magnetic flux guide to have an L-shape at the same time, and the magnetic poles may be provided with magnetic plates at both ends, so that the magnet side does not constitute a closed magnetic circuit alone, and the magnetic circuit part No short circuit occurs.

When the width and depth of the magnetic plate attached to the magnet is made smaller than that of the magnet, the magnetic plate is also magnetized to the same pole as the magnetic pole. A repulsive action occurs. For this reason, if the magnetic plate is biased to the side facing the Hall effect element, the magnet area on the side not facing the Hall effect element becomes larger, so that the repulsion action becomes stronger, and therefore the magnetic flux is directed to the Hall effect element side. Will be pushed away.

When the magnetic flux collecting yoke is brought in front of the Hall effect element, the magnetic flux easily passes through the magnetic material, so that the magnetic flux is collected by the magnetic flux collecting yoke and passes through the Hall effect element.

[0012]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a main part when the Hall effect sensor device according to the present invention is used for ignition timing control of an internal combustion engine. 1 is a part of a cylinder block of the engine, 2 is a rotating shaft, 3 is a magnetic flux shutter made of a magnetic material, and is fixed to the rotating shaft 2 so as to rotate integrally with the rotating shaft 2.

Reference numeral 4 denotes a shutter portion provided at the tip of the magnetic flux shutter 3, which is formed by cutting a predetermined number of magnetic materials forming the magnetic flux shutter 3 at equal intervals along the circumferential direction. 5 is a magnet, 6A1, 6A2, 6B1, 6B2,
6B3 and 6C are magnetic flux guides, 6A1 and 6A2 are magnetic plates, 6B1, 6B2 and 6B3 are return yokes, 6C
Is referred to as a magnetic flux collecting yoke. Reference numeral 7 denotes a Hall effect element, which includes a magnet 5, magnetic flux guides 6A1, 6C, 6B2, and 6B.
The magnetic flux shutter 3 is disposed in a magnetic path formed by the magnetic paths 1, 6B3 and 6A2, and is configured to move in a direction crossing the magnetic path when rotating. 8 is a magnet 5 and magnetic flux guides 6A1, 6A2, 6B1, 6B2, 6B3, 6
C is a mold frame that integrates the Hall effect element 7 integrally.

Next, in the present embodiment, the magnetic plates 6A1 and 6A2 are each shorter in width a and height b (see FIG. 2) by 1 mm than the magnet 5, and the magnet 5
(See FIG. 1).

The cross-sectional area of the protrusion 6B2 of the return yoke is larger than the magneto-sensitive area of the Hall effect element 7, and
The width d of B3 is almost the same as the width c of the magnet 5. Although the Hall effect element 7 appears to be larger than the cross-sectional area of the protrusion 6B2 of the return yoke in the figure, the element itself is small in the state covered by the package. FIG. 3 shows a perspective view of the return yokes 6B1, 6B2, 6B3. Then, the centers of the plate thicknesses of the magnetic plates 6A1 and 6A2 are arranged so as to coincide with the plate thickness centers of the protrusions 6B1 and 6B2 of the return yoke, respectively.

As shown in FIG. 4, the magnetic flux collecting yoke 6C has a stepped disk shape and is fixed in the mold frame 8.
The height of the protrusion 6B1 of the return yoke on the side of the Hall effect element 7 has an optimum value. However, this optimum value varies depending on the length and shape of the magnetic path of the entire return yoke. For example, in this embodiment, the magnetic path length is 9 mm, and the protrusion 6B on the element 7 side is used.
1, the width of the protrusion 6B2 on the opposite side is 5 mm, and the height e of the protrusion 6B1 is 1 mm.

Next, the operation will be described. In the above configuration, when the rotating shaft 2 rotates due to the rotation of the internal combustion engine, the magnetic flux shutter 3 integrally fixed thereto also rotates, and the shutter portion 4 at the tip moves in the magnetic circuit including the Hall effect element 7. Since the shutter portion 4 is formed in a notch shape, it is given to the Hall effect element 7 as a change in magnetic flux according to the rotation of the rotating shaft 2. The Hall effect element 7 converts this into an electric signal and processes this output signal by a processing circuit (not shown), thereby detecting the rotation angle of the rotating shaft 2 and controlling the ignition timing. .

The thickness of the magnetic plates 6A1 and 6A2 is not particularly limited. The thicker the magnetic plates 6A1 and 6A2, the better the magnetic flux guide and the maximum magnetic flux density without a shutter. If flux shutter 4
Is limited, it is desirable that the thickness be as thick as possible within a range in which the magnetic flux can be shut off.

It is desirable that the magnetic flux collecting yoke 6C be as thin as possible (eg, 1 to 1.5 mm) and have a wide area.

As described above, according to this embodiment, the magnetic plate 6
The width a and height b of A1 and 6A2 are made narrower than the magnets 5 and are biased toward the Hall effect element 7 to utilize the repulsive action of magnetic force, or a magnetism collecting yoke 6C is disposed in front of the Hall effect element 7. In addition to the magnetism effect, the height e of the projection 6B1 of the return yoke is particularly optimally adjusted according to the shape and dimensions, thereby further increasing the magnetism effect as a whole.
A margin of magnetic force can be provided.

In this embodiment, since the magnetic flux collecting yoke 6C has a stepped shape, the magnetic flux collecting yoke 6C does not fall off the mold frame 8 and also prevents leakage when resin is injected into the frame for resin sealing. Has become.

As shown in FIG. 5, except for the projection 6B1 on the Hall effect element side of the return yoke, the Hall effect element 7 is directly connected to the magnetic plate 6 of the horizontal section 6B3 of the return yoke.
A structure attached to a position facing A1 is also possible. The width of the tip of the return yoke 6B3 is larger than the width of the magnetic sensing part of the Hall effect element 7.

[0023]

As is apparent from the above description of the embodiment, the present invention makes it possible to increase the length of the magnetizing direction by adjusting the magnetizing direction of the magnet to the radial direction of the shutter whose space is loose. In addition, it is possible to provide a sufficient magnetic force margin for operating the Hall effect element even with a severe temperature change or a durability change in an internal combustion engine or the like. Also, the width and height of the magnetic plate are made smaller than that of the magnet, and the magnetic flux repulsion effect by biasing to the Hall effect element side is used. Magnetizing the effect element,
Further, the magnetic force can be given a margin.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an embodiment of a Hall effect type sensor device of the present invention.

FIG. 2 is a side view of the magnetic circuit unit viewed from an arrow A side in FIG. 1;

FIG. 3 is a perspective view of the return yoke.

FIG. 4A is a plan view of the magnetic flux collecting yoke, and FIG.

FIG. 5 is a perspective view of another type of return yoke.

FIG. 6 is a sectional view of a main part of a conventional Hall effect sensor device.

FIG. 7 is a plan view of a magnetic flux shutter in the sensor device.

[Explanation of symbols]

 Reference Signs 2 Rotating shaft 3 Magnetic flux shutter 5 Magnet 6A1, 6A2 Magnetic plate 6B1, 6B2, 6B3 Return yoke 6B1, 6B2 Projection of return yoke 6C Magnetic flux collecting yoke 7 Hall effect element

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G01B ⁷ /00-7/34 101 G01D 5/00-5/252 G01D 5/39-5/62

Claims (4)

(57) [Claims] 1. A disk-shaped magnetic flux shutter fixed to a rotating shaft and fixed to the rotating shaft and having notches at predetermined intervals along a circumferential direction thereof, and a magnetization direction of the shutter is parallel to a shutter plane. A magnet with magnetic plates mounted on both poles, a Hall effect element opposed to one of the magnetic plates with the magnetic flux shutter interposed therebetween, and a larger area than the magneto-sensitive area of the Hall effect element. And a return yoke having at least a protruding portion, the protruding portion being arranged close to the Hall effect element, and a return yoke having the other end facing the other side of the magnetic plate with the magnetic flux shutter interposed therebetween. Effect type sensor device. 2. The Hall effect type sensor device according to claim 1, wherein a protrusion having a cross-sectional area larger than the magneto-sensitive area of the Hall effect element is provided at the tip of the return yoke. 3. The Hall effect according to claim 1, wherein the magnetic plates mounted on both poles of the magnet have a smaller area than both pole surfaces of the magnet, and are mounted on the edge facing the magnetic flux collecting yoke and the return yoke. Type sensor device. 4. The Hall-effect sensor device according to claim 1, wherein the height of the projection below the Hall-effect element of the return yoke is o, that is, the Hall-effect element is arranged at one end of the horizontal portion of the return yoke.