JPH08189932A - Pickup sensor, and speed sensor using it - Google Patents

Abstract

PURPOSE: To let leakage magnetic fluxes fly farther by utilizing the repellence between the same-polarity magnetic poles of two magnets joined to each other so that the same magnetic poles can be faced to each other. CONSTITUTION: A pickup sensor is provided with two magnets 7 and 9 which are joined together with an adhesive 11 so that the same-polarity magnetic poles of the magnets 7 and 9 can be faced to each other, back yokes 13 and 15 which are provided in parallel on the other magnetic pole sides of the magnets 7 and 8, a galvanomagnetic conversion element 19 which is provided adjacent to the magnets on the extension line of the gap between the joined magnets 7 and 9 and converts magnetism into an electric current by utilizing the variation of magnetic fluxes made to fly by the repellence between the facing same-polarity magnetic poles of the magnets 7 and 9, and a yoke 21 which converges the magnetic fluxes made to fly by the conversion element 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pickup sensor for making a magnetic flux fly farther by two magnets which are joined so that the same magnetic poles face each other, and a vehicle speed detecting device to which the pickup sensor is applied.

[0002]

2. Description of the Related Art Conventionally, as an example of converging a magnetic flux diffused and leaked from a bias magnet into a space, for example, the actual open sho 60
-191967 and Japanese Utility Model Laid-Open No. 3-10258.

The above-mentioned Japanese Utility Model Publication No. 60-191967 will be described with reference to FIG. In the rotating body sensor, a magnet ring 105, which is located concentrically with the magnet 103, is magnetized on the outer circumference of the tip of a magnet 103 in a nonmagnetic case 101. The magnet ring 105 is fixedly held by the case 1. The magnetizing direction of the magnet ring 105 is the magnetic pole (N pole) at the tip of the magnet 103.
A magnetized in advance so that the magnetic pole (N pole) having the same pole as the inner circumference and the other pole (S pole) the outer pole is used. Thereby, the magnetic flux leaking from the tip of the magnet 103 is focused.

On the other hand, Japanese Utility Model Laid-Open No. 3-10258 discloses a structure shown in FIG.
As shown in the sectional view of FIG. Pickup sensor 11
In the first example, the pole piece 113 has a stepped portion 117 formed by partially notching a surface of the pickup portion on the opposite side of the pickup portion to the tone wheel 115, and a magnet piece 119 made of a permanent magnet for controlling the direction of the magnetic flux. Is fixed by adhesion. Since the magnet piece 119 has an N pole at the surface of the permanent magnet 121 that is joined to the pole piece 113, the surface facing the tone wheel 115 is set as the N pole and the outer surface side is set as the S pole. Thereby, the magnet piece 11
At the end of the coil 9 on the side of the coil 123, a line of magnetic force a that wraps around from the joint surface with the pole piece 113 to the outer surface is generated. This line of magnetic force a is derived from the original permanent magnet 121 to the pole piece 1.
The direction of the magnetic flux that is opposite to the magnetic force line A that goes toward the tone wheel 115 via 13 and that the magnetic force line A passes through the magnet piece 119 and leaks out is regulated.
The magnetic flux density toward 5 can be increased.

[0005]

However, in Japanese Utility Model Unexamined Publication No. 60-191967, it is unclear how to magnetize the magnet ring 105 to the outer circumference of the tip portion of the magnet 103. Temporarily, magnet ring 10
Even if No. 5 could be magnetized, the effect of flying the leakage magnetic flux farther in the direction of the gear-shaped magnetic body 107 facing the cylindrical permanent magnet 103 is small, and the distance between the surface of the magnet 103 and the gear-shaped magnetic body 107 is small. Over a certain distance, for example 2mm
In the above case, the effect of the leakage magnetic flux density on the surface of the gear-shaped magnetic body 107 is not observed.

On the other hand, in Japanese Utility Model Laid-Open No. 3-10258, the magnet piece 11 provided at the tip of the pole piece 113 is used.
7 has the effect of slightly increasing the leakage magnetic flux to the tone wheel 115 side. However, since the magnetic flux also leaks from the S pole side of the magnet piece 117, the leakage magnetic flux to the tone wheel 115 side is concentrated at one point, but the magnetic flux was not strengthened.

The present invention has been made in view of such conventional problems, and an object thereof is to join two magnets so that the same magnetic poles face each other, thereby making the leakage magnetic flux fly farther. (EN) It is possible to provide a pickup sensor and a vehicle speed detection device to which the pickup sensor is applied to increase the passage amount of leakage magnetic flux to improve the detection accuracy of the rotational position of the gear rotor by applying the pickup sensor.

[0008]

In order to achieve the above object, the first invention according to claim 1 is to provide two magnets which are bonded with an adhesive so that the same magnetic poles face each other with a predetermined gap, The two magnets are arranged adjacent to each other on the extension of the gap where the two magnets are joined, and the back yoke that is arranged in parallel on the magnetic pole side opposite to the same magnetic pole that faces the two magnets. The gist of the present invention is to provide a magnetoelectric conversion element that converts into a current by a change in the magnetic flux that is blown by the repulsion of the facing identical magnetic poles, and a yoke that focuses the magnetic flux that is blown to the magnetoelectric conversion element on the magnetoelectric conversion element.

According to a second aspect of the present invention, a rotating gear rotor, a yoke arranged to face a ridge and a valley of the gear rotor, respectively, for focusing a magnetic flux in a certain direction, and each of the yokes. Adjacent to each of both ends of the magnetoresistive element whose resistance value changes due to the change of magnetic flux, and an adhesive so that the same magnetic pole faces the extension of the approximate center between the magnetoresistive elements. The gist of the present invention is to provide two magnets that are joined with a predetermined gap, and a back yoke that is provided in parallel on the magnetic pole side opposite to the same magnetic pole facing the two magnets.

According to a third aspect of the present invention, two magnets are bonded with an adhesive so that the same magnetic poles face each other with a predetermined gap, and a magnetic pole different from the same magnetic poles facing each other of the two magnets. And a back yoke arranged in parallel with each other on the side, and adjacent to the extension of the gap where the two magnets are joined,
A magnetoelectric conversion element that converts into a current by a change in magnetic flux that is blown by the repulsion of the same magnetic poles facing each other of the two magnets,
A yoke for converging the magnetic flux blown to the magnetoelectric conversion element to the magnetoelectric conversion element and an opposite side to the magnetoelectric conversion element on the extension of the gap where the two magnets are joined via the two magnets. The gist of the present invention is to provide the same magnetic pole of the two magnets and a magnet joined so that the same magnetic pole faces each other.

According to a fourth aspect of the present invention, there are provided two magnets which sandwich a yoke in the gap so that the same magnetic pole faces each other and are joined by an adhesive, and the yoke which sandwiches the yoke. Back magnets arranged in parallel on the same magnetic pole and different magnetic pole sides of the magnets, and adjacent to each other on the extension of the yoke sandwiched between the two magnets, the two magnets facing each other being the same. A magnetoelectric conversion element that converts into a current by a change in magnetic flux that is blown out due to repulsion of magnetic poles, and a surface of the yoke that is sandwiched by the two magnets and the yoke other than the surface of the yoke on the side of the magnetoelectric conversion element, The gist of the present invention is to provide a non-magnetic material having a shape that narrows the end of the yoke on the magnetoelectric conversion element side.

According to a fifth aspect of the present invention, two magnets are joined with an adhesive so that the same magnetic poles are arranged in parallel in the same direction with a predetermined gap, and the two magnets are joined together. A magnetic sensitive element which is arranged adjacent to the extension of the gap and which is incorporated in a magnetoelectric conversion element which converts into a current by a change in magnetic flux that is skipped from the same magnetic pole of the two magnets and which detects the skipped magnetic flux. The point is to have prepared.

According to a sixth aspect of the present invention, a magnet having a groove formed in the same magnetic pole is arranged adjacent to an extension of the groove formed in the same magnetic pole of the magnet. The gist of the present invention is to include a magneto-sensitive element that is built in a magnetoelectric conversion element that converts a magnetic flux that is blown from a magnetic pole into a current and that detects the magnetic flux that is skipped.

[0014]

According to the first aspect of the present invention, when configured as described above, the two magnets are bonded with a predetermined gap by an adhesive so that the same magnetic poles face each other, and the same magnetic poles that the two magnets face each other. The back yokes arranged side by side on different magnetic poles are arranged adjacent to each other on the extension of the gap where the two magnets are joined, and the magnetic fluxes emitted by the repulsion of the same magnetic poles facing each other of the two magnets By providing the magnetoelectric conversion element that converts into a current by a change and the yoke that focuses the magnetic flux that is blown to the magnetoelectric conversion element on the magnetoelectric conversion element, the two magnets are forcibly joined and the repulsion of the same magnetic pole is provided. Since, the leakage magnetic flux can be flown further away.

A second aspect of the present invention is directed to a rotating gear rotor, a yoke arranged to face a ridge and a valley of the gear rotor, respectively, for converging a magnetic flux in a fixed direction, and both ends of each of the yokes. Adjacent to each other with an adhesive so that the same magnetic pole faces the extension of approximately the center between the magnetoresistive elements, which are arranged facing each other and whose resistance value changes due to the change of the magnetic flux. By providing two magnets and a back yoke arranged in parallel on the magnetic pole side different from the same magnetic pole facing each other, the rotational position of the gear rotor by at least two sets of two magnets can be determined. Since the detection is performed, the pickup sensor can be applied to increase the passage amount of the leakage magnetic flux and improve the detection accuracy of the rotation position of the gear rotor.

According to a third aspect of the present invention, two magnets are bonded to each other with an adhesive so that the same magnetic poles face each other with a predetermined gap, and the two magnets are arranged side by side on the same magnetic pole opposite to the same magnetic pole. Which is disposed adjacent to the back yoke and an extension of the gap where the two magnets are joined, and is converted into a current by the change in the magnetic flux that is blown by the repulsion of the same magnetic pole facing each other. A conversion element, a yoke for converging the magnetic flux blown to the magnetoelectric conversion element on the magnetoelectric conversion element, and the two magnets for the magnetoelectric conversion element on the extension of the gap where the two magnets are joined. Since the same magnetic pole of the two magnets and a magnet joined so that the same magnetic pole faces each other are provided on the opposite side through the magnetic flux generated by the repulsion of the same magnetic pole, the two magnets are connected to the magnetoelectric conversion element. Bonded to the other side through Since further repelled by the same poles of the magnets that can skip flux leakage in the direction of the magneto-electric conversion element more distant.

According to a fourth aspect of the present invention, two magnets sandwiching a yoke in the gap so that the same magnetic poles face each other and joined by an adhesive, and the two magnets sandwiching the yoke are the same. A back yoke arranged in parallel with the magnetic pole different from the magnetic pole and an extension of the yoke sandwiched between the two magnets are arranged adjacent to each other, and are blown by the repulsion of the same magnetic poles facing each other of the two magnets. And a surface of the yoke sandwiched by the two magnets, and the yoke other than the surface of the yoke on the side of the magnetoelectric conversion element, and the magnetoelectric conversion element side. Since the magnetic flux is focused on the end portion on the side of the magnetoelectric conversion element by providing the nonmagnetic material having a shape that narrows down the end portion of the yoke, the leakage magnetic flux can be flown further in the direction of the magnetoelectric conversion element. You can

According to a fifth aspect of the present invention, two magnets are bonded with a predetermined gap by an adhesive so that the same magnetic poles are arranged in parallel and in the same direction, and an extension of the gap where the two magnets are bonded. By including a magnetic sensitive element that is disposed adjacent to each other and is incorporated in a magnetoelectric conversion element that converts into a current by a change in magnetic flux skipped from the same magnetic pole of the two magnets, and a magnetic sensitive element that detects the skipped magnetic flux Since the same magnetic poles are arranged in parallel and the magnetic fluxes in the same direction interfere with each other, the leakage magnetic flux can be flown further away from the magnetic sensing element.

According to a sixth aspect of the present invention, a magnet having a groove formed in the same magnetic pole is disposed adjacent to an extension of the groove formed in the same magnetic pole of the magnet, and the groove has the same groove. Since the magnetic flux of the same magnetic pole in the groove interferes with each other because it is built in the magnetoelectric conversion element that converts into a current according to the change of the magnetic flux skipped from the magnetic pole and the magnetic sensitive element for detecting the magnetic flux skipped, the magnetic flux of the same magnetic pole in the groove interferes with each other. The leakage magnetic flux from can be made to fly further.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the overall construction of a pickup sensor according to the present invention and a vehicle speed detecting apparatus to which the pickup sensor is applied according to a first embodiment.

In FIG. 1, the magnetic pickup 1 has a sensor housing 3 covering the entire housing of the magnetic pickup 1. A magnet unit 5 is arranged in the sensor housing 3 at a substantially central portion. The magnet unit 5 has a permanent magnet (hereinafter referred to as a magnet) 7 arranged such that the center side of the sensor housing 3 is the N pole and the S pole different from the N pole is the outer surface side, and the magnet 7 concerned. And a permanent magnet (hereinafter, referred to as a magnet) 9 arranged so that an N pole having the same magnetic pole as the N pole faces each other and the S pole different from the N pole is on the outer surface side. There is. The magnet unit 5 is forcibly joined by an adhesive in order to cause repulsion of magnetic flux between N poles, which are the same magnetic poles of the magnet 7 and the magnet 9. Further, the magnets 7 and 9 of the magnet unit 5 have a large energy product of the magnets when size reduction is required due to the size restriction of the magnetic pickup 1, such as a samarium / cobalt magnet or a neodymium / iron / boron magnet. Rare earth magnets are suitable. In the first embodiment, such a rare earth magnet is used, and the shape is 4
The size is × 2 × 4 mm. On the other hand, when it is not necessary to downsize the magnet unit 5, an inexpensive magnet having a small energy product such as an alnico magnet or a funlite magnet is used.

At a predetermined distance (gap) of the same magnetic pole between the magnet 7 and the magnet 9 forcibly joined to the magnet unit 5,
The adhesive 11 is filled. As a result, there is an effect that the leakage magnetic flux from the joint surfaces is further flown according to the size of the area of the joint surfaces of the magnets 7 and 9 to be joined. The gap between the magnet 7 and the magnet 9 that fly the leakage magnetic flux farther is 0.
It is 6 to 1.2 mm.

A back yoke 13 is arranged in contact with the S pole on the left side of the magnet 7 in the drawing, and a back yoke 15 is arranged in contact with the S pole of the magnet 9 on the right side in the drawing. Has been done. The back yokes 13 and 15 include the magnet 7 and the magnet 9.
Among the leakage fluxes from the joint surface with and, it brings about the effect of suppressing the leakage fluxes from the side surface (back and front sides of the paper in Fig. 1), and it is desirable to use a material with a high magnetic permeability, for example, an inexpensive SIOC material. Is appropriate. Further, when the back yokes 13 and 15 have the same length as the left and right side surfaces of the magnets 7 and 9 in the figure, the leakage flux from the joint surface of the magnets 7 and 9 from the vertical direction in the figure with respect to the adhesive 11 is eliminated. The leakage flux component is pulled in the left and right directions in the figure by the back yokes 13 and 15, so that the originally used up and down magnetic flux is weakened. Therefore, in this embodiment, the back yokes 13 and 15 are
The vertical length of the side surface is shorter than the vertical length of the side surfaces of the magnets 7 and 9. The back yokes 13 and 15
Has a shape of, for example, 3 × 1.5 × 3 mm.

The resin component 17 covering the side surface of the back yoke 13 of the magnet unit 5 to the upper surfaces of the magnets 7 and 9 and the side surface of the back yoke 15 is a circuit for fixing the holder of the magnet unit 5 and a magnetoelectric conversion element 19 described later. It also serves as a substrate. A wiring pattern is formed on the upper surface of the resin component 17 in the figure. Magnetoelectric conversion element 1 provided on the extension of the adhesive 11 via the resin component 17
The magnetic flux is blown by the repulsion of the N poles of the N pole of the magnet 7 and the N pole of the magnet 9 of the magnet unit 5 to the surface of the built-in magnetic sensing element (not shown). The magnetoelectric conversion element 19 is formed of a Hall element having a Hall element having a Hall effect, a Hall IC, or a magnetoresistive element having a magnetoresistive effect. A yoke 21 is arranged in the approximate center of the upper surface of the magnetoelectric conversion element 19 in the figure. The yoke 21 is arranged to attract the leakage magnetic flux that is blown away by the repulsion of the two magnets 7 and 9 having the same magnetic pole toward the magnetoelectric conversion element 19, and a larger amount of the leakage magnetic flux is magnetoelectrically converted. It is arranged on the upper surface of the magnetoelectric conversion element 19 so as to be focused on the element 19. The material of the yoke 21 is the same as that of the back yokes 13 and 15 described above.

A rubber bushing 23 screwed into a resin 29, which will be described later, at the center of the lower end of the sensor housing 3.
A wire harness 25 described later is penetrated. The rubber bushing 23 is made of an elastic material such as rubber to prevent disconnection due to bending of the wire harness 25. The rubber bushing 23 has a corrugated outer peripheral surface in order to prevent water from entering the inside of the magnetic pickup 1. A wire harness 25 that bends from the rubber bushing 23 to the right in the drawing and bends from the lower right end of the resin component 17 in the drawing to the side surface of the resin component 17 includes a terminal 27 described later.
Are fixed by being soldered to a resin component 17 that also serves as a circuit board. In addition, the wire harness 25
Are electrically connected to the terminals 27 in the upper part of the drawing via the wires 28. The gap inside the sensor housing 3 is filled with the resin 29 by potting a resin material.

FIG. 2A is a plan view in which the shapes of the back yokes 13 and 15 of the first embodiment are modified, and FIG. 2B is a front view in which the shapes of the back yokes 13 and 15 are modified. Show.
The widths of the back yokes 13 and 15 on the plane shown in FIG. 9A are the same as those of the magnets 7 and 9. As shown in FIG. 6B, the back yokes 13 and 15 arranged in parallel with each other in contact with the side surfaces of the magnets 7 and 9 in the figure are slanted outward from the portion joined to the magnets 7 and 9. The shape is notched and inclined. The effects of the modification shown in FIGS. 2A and 2B are the same as those of the first embodiment.

A modification of the magnet unit 5 of the first embodiment is shown in FIG. 2 (c).

At the lower ends of the magnets 7 and 9 arranged in the magnet unit 5 shown in FIG. 1 in the figure, the magnets 7 and 9 having the same magnetic pole facing each other are shorter than the length of the magnet unit 5. A magnet 31 is arranged such that its N pole faces the 9 side. Leakage magnetic fluxes from the magnets 7 and 9 having the same magnetic poles facing each other due to the arrangement of the magnets 31 are repelled by the N poles of the magnets 31, so that the magnetic flux density of the magnetic flux density increases in the direction of the magnetoelectric conversion element 19 (not shown) on the upper side in the figure. It will fly high magnetic flux. The gap between the magnets 7 and 9 and the magnet 31 is equal to that of the adhesive 1
1 and the gap between the magnets 7 and 9 is 0.6 to 1.2 m like the gap between the magnet 7 and the magnet 9 in the first embodiment.
m.

The production procedure of the above-described first embodiment will be described with reference to the diagram showing the production process of FIG.

First, the magnets 7 and 9 are joined to the yoke (ST1), and the two magnets 7 and 9 have the same magnetic pole N.
The poles are forcibly joined so that they face each other, and the magnet unit 5
Is created (ST2).

On the other hand, the case is formed by plating a metal foil from the upper surface to the right side in the figure. The case may be manufactured, for example, by bonding a synthetic resin foil serving as an insulating layer to a non-magnetic metal surface of aluminum, and bonding the synthetic resin foil to form a circuit pattern on the synthetic resin with a copper foil. Good (ST3).

A Hall IC or an MR element, which will be described later, and a chip resistor are soldered to the upper surface of the case in the drawing and joined to the case (ST4).

On the other hand, the rubber bush 23 is inserted into a predetermined portion of the wire harness (ST5). After the insertion, the terminal 27 is inserted into the end of the wire harness (ST6).

Next, the terminals 27 are soldered to the case,
Join the wire harness (ST7). After joining, the above-mentioned magnet unit 5 is assembled to manufacture a rotation sensor unit (ST8).

FIG. 4 is a sectional view showing the overall construction of the second embodiment of the present invention.

The second embodiment is an application example of the first embodiment, and uses an MR (magneto-resistive) element having a magnetoresistive effect whose resistance value changes according to a magnetic field as a magnetoelectric conversion element to detect a vehicle speed. It is an example applied to.

The vehicle speed detecting device uses two sets of the magnet units of the first embodiment to measure the rotational position of the gear to be measured with higher resolution.

First, as described with reference to FIG. 1, the magnet unit 5a disposed on the left side of the center of the drawing is forcibly joined so that the N poles of the same magnetic poles of the magnets 7a and 9a face each other. The adhesive 11a is filled in the gap between the magnet 7a and the magnet 9a. On the other hand, the magnet unit 5a
The magnet unit 5b arranged on the right side of the figure
Is forcibly joined so that the N poles of the same magnetic poles of the magnets 7b and 9b face each other, and the gap between the magnets 7b and 9b is filled with the adhesive 11b. The adhesive 11a
In addition, on the upper portion of the adhesive 11b in the drawing, patterns (hereinafter, referred to as patterns) 33a to 35b of four magnetoresistive elements including MR elements are formed. A yoke 21a is provided substantially in the center between the patterns 33a, 35a on the magnet unit 5a side, and a pattern 33 on the magnet unit 5b side is provided.
A yoke 21b is arranged in the approximate center between b and 35b. A gear rotor 37 to be measured is provided on the upper part of the sensor housing 3 joined to the yoke 21a and the yoke 21b in the figure. The gear rotor 37 rotates counterclockwise.

The pattern 33a on the magnet unit 5a side
The yoke 21a arranged substantially in the center between the pattern 35a and the pattern 35a faces the mountain 39a of the gear rotor 37, and the yoke 21b arranged substantially in the center between the pattern 33b and the pattern 35b of the magnet unit 5b. Is the gear rotor 37
It is arranged so as to face the valley 39d. Further, even when the gear rotor 37 is rotating, the yoke 21a remains in the gear rotor 3
The peaks 7 and the yoke 21b are arranged to face the valleys of the gear rotor 37, respectively. That is, the yokes 21a and 21
b is provided so as to face the peaks or valleys of the gear rotor 37 in order to improve the detection resolution of the rotational position of the gear of the gear rotor 37. When the magnetic flux is blown to the mountain of the gear rotor 37, each pattern detects a strong resistance value,
When the magnetic flux is blown to the valleys of the gear rotor 37, each pattern detects a weak resistance value.

The patterns 33a and 35a on the upper portion of the adhesive 11a of the magnet unit 5a are formed at positions where their phases are shifted by 90 ° with respect to the gear pitch of the gear rotor 37. Similarly, the patterns 33b and 35b on the upper portion of the adhesive 11b of the magnet unit 5b are formed at positions where their phases are shifted by 90 ° with respect to the gear pitch of the gear rotor 37. The patterns 33a and 35a and the patterns 33b and 3
Each of the two patterns 5b and 5b is formed as a set of so-called detection units that detect the rotational position of the gear rotor 37. The distance between the yoke 21a and the yoke 21b is equivalent to 1.5 rotations of the gear rotor 37 which is 90 ° × 6 = 540 °. The second embodiment has a yoke 2
The distance between 1a and the yoke 21b should be 1.5
Although the interval corresponding to the rotation is set, the interval is not limited to 1.5, and the interval of 0.5 rotation or 2.5 rotation can be applied, for example. In addition, the two magnet units 5 of the first embodiment described above
It is also possible to apply as a set to the vehicle speed detecting device as in the second embodiment.

Next, a plan view of the patterns 33a-35b is shown in FIG.

In the figure, a pattern 41a, a pattern 35a, a pattern 33b, and a pattern 35b are formed in parallel with each other in the vertical direction from the right side in the figure, which is indicated by the diagonal lines in the figure, in a substantially central portion of the substrate 41. A power supply (Vcc) 43 is formed in the lower right portion of the substrate 41, an electrode 45 is formed in the upper right portion of the drawing, an electrode 47 is formed in the lower left portion of the drawing, and a GND (ground) 49 is formed in the upper left portion of the drawing. The patterns 33a to 35b are thin film resistors of a compound semiconductor made of, for example, indium antimony. When the distance between the patterns 35a and 33b becomes large, it may be divided into two magnetoresistive elements instead of one magnetoresistive element as shown in FIG.

As described above, the second embodiment uses two magnetoresistive elements composed of four magnetoresistive elements (patterns) and two magnets forcibly joined so that the same magnetic poles face each other. Utilizing two sets of magnet units, the gear rotor 37
Are measured respectively. As a result, the resolution of detecting the rotational position of the gear rotor 37 can be doubled.

A third embodiment of the present invention is shown in FIGS. 6 (a), 6 (b),
This will be described using (c).

The third embodiment is shown in FIGS. 1 and 2 (a).
, (B) and (c), the yoke 57 is placed in the gap between the magnet 53 and the magnet 55 which are forcibly joined so that the same magnetic poles face each other.
Is sandwiched between. The upper part of the yoke 57 in the figure is
As shown in FIG. 6 (a), the leakage magnetic flux from the gap between the magnet 53 and the magnet 55, which are joined so that the N poles of the same magnetic pole face each other, is used as a rotation sensor. It is formed up to the same surface as the upper end. on the other hand,
The lower end portion of the yoke 57 sandwiched in the gap between the magnet 53 and the magnet 55 in the figure is shorter than the lower end portions of the magnets 53 and 55. Since the yoke 57 is sandwiched in the gap between the magnet 53 and the magnet 55, the magnet 5 is joined so that the same magnetic poles face each other.
This is because the leakage magnetic flux from the lower portions of 3, 55 is pulled to the upper portion in the figure via the yoke 57.

A sectional view taken along the line AA of FIG. 6 (a) is shown in FIG. 6 (b). The width of the yoke 57 is such that the magnets 53, 55 joined so that the N poles of the same magnetic pole face each other have no leakage flux from the vertical direction in the figure to the magnets 53, 55.
Narrower than. This is because the magnetic repulsion lines (shown by broken lines in the figure) from the magnets 53 and 55 joined so that the same magnetic poles face each other in the AA cross-sectional view of FIG. This is so that the leakage magnetic flux from the end portions of the magnets 53 and 55 that pulls in can be pulled inward (toward the front side in the drawing).

FIG. 6 (c) is a sectional view taken along line BB of FIG. 6 (a). The yoke 57 is covered with the surface sandwiched between the two magnets 53 and 55 by the non-magnetic material 63, the left and right side surfaces in the figure, the surface of the magnetoelectric conversion element (not shown), and the bottom surface in the figure. The yoke 57 and the non-magnetic body 63 are narrower than the central portion in the drawing because the end portion on the magnetoelectric conversion element side of the upper end portion in the drawing is narrowed down. As a result, the leakage magnetic flux due to the repulsion of the same magnetic poles of the magnets 53 and 55 (not shown) is focused on the center of the upper end portion in the figure, and a large amount of magnetic flux from the central portion is absorbed by the magnetoelectric conversion element 19 in the upper portion of the figure. It will be possible to fly toward (outside the figure).

With the above structure, by sandwiching the yoke 57 in the gap between the magnets 53 and 55 joined so that the same magnetic poles face each other, the leakage magnetic flux from the magnets 53 and 55 is narrowed down by the non-magnetic material 63. You can fly stronger and further from the edges.

The overall construction of the fourth embodiment of the present invention will be described with reference to the sectional view of FIG.

In the fourth embodiment, the two magnets are forcibly joined so that the same magnetic poles face each other in the first embodiment, whereas the same magnetic poles are arranged in parallel and in the same direction. The two magnets are forcibly joined.

First, the N poles of the same magnetic poles of the magnet 67 and the magnet 69 arranged in the magnet unit 65 are on the magnetoelectric conversion element 19 side in the upward direction in the figure, and the S poles different from the N pole are in the figure. It is disposed on the rubber bushing 23 side, which will be described later, in the downward direction. In addition, the adhesive 11 is provided in the gap between the magnet 67 and the magnet 69.
Is filled. On the left and right side surfaces and the upper surface side of the magnet unit 65 including the magnet 67 and the magnet 69,
A resin component 17 that doubles as a case of the magnet unit 65 and a circuit board is formed. An electrode pattern is formed on the surface of the resin component 17 opposite to the magnet unit 65 side, and the magnetoelectric conversion element 19 is soldered. A magneto-sensitive element 71 for detecting a magnetic flux passing therethrough is built in approximately the center of the magnetoelectric conversion element 19. The air gap from the N pole surface of the magnets 67 and 69 of the magnet unit 65 to the magnetic sensing element 71 is 0.5 to 1.
It is 0 mm.

Next, the end portion 73 at the lower end of the magnet unit 65.
A rubber bushing 2 made of an elastic material such as rubber is provided approximately in the center of
3 is provided. The wire harness 25 that bends from the rubber bushing 23 to the right in the drawing and bends from the lower right end of the resin component 17 to the side surface of the resin component 17 is electrically connected to the terminal 27 at the upper portion in the drawing via the wire 28. It is connected to the. The terminal 27 is soldered to the resin component 17 to fix the wire harness 25.

Further, the gap inside the sensor housing 3 is filled by potting the resin 29.
The magnet unit 65, the magnetoelectric conversion element 19 and the like are entirely covered by the sensor housing 3 made of a non-magnetic metal material or synthetic resin material. A gear rotor 75 is arranged on the upper portion of the sensor housing 3 in the figure.

With the above structure, the leakage magnetic fluxes from the N pole surface near the joint surfaces of the two magnets 67 and 69 in which the same magnetic poles are forcibly joined in parallel in the same direction interfere with each other and the N pole surfaces concerned. The number of magnetic fluxes leaking in the vertical direction and passing through the magnetic sensing element 71 of the magnetoelectric conversion element 19 increases.

A modified example of the fourth embodiment will be described with reference to FIG.

In the fourth embodiment described above, the same magnetic pole is formed in the same direction in the magnetic sensitive element 71 incorporated in the magnetoelectric conversion element 19.
While the individual magnets are forcibly joined, the modification is one in which a rectangular notch groove 81 is formed in the longitudinal direction of the N pole surface of the magnet 79. With the above configuration, the magnetic flux from the N-pole surface of the magnet 79, which is separated from the end portion 83 of the groove 81, is bent in the left and right directions with respect to the groove 81 from the middle of the upper portion in the drawing and is blown. However, as they approach the end portion 83, the leakage magnetic fluxes interfere with each other and fly in the direction perpendicular to the N pole surface of the magnet 79. As a result, the magnetic flux near the end portion 83 of the groove 81 becomes N
Since it is blown in the direction perpendicular to the pole faces, the magnetic flux passing through the magnetoelectric conversion element 19 (not shown) disposed above the groove 81 in the drawing increases.

Here, the situation of the leakage magnetic flux due to the joining state of the magnets will be described with reference to FIGS. 9 (a), 9 (b) and 9 (c). First,
Fig. 9 (a) shows the leakage flux from a single magnet with the N pole on the upper side and the S pole on the lower side in the figure. The leakage flux from the N pole is from the left and right directions shown by the dotted line in the figure to the S pole direction. It is skipped while drawing an ellipse. Next, in FIG. 9B, the N pole is on the upper side in the figure,
The case where two magnets with south poles are forcibly joined to the lower side is shown. Due to the repulsion between the N poles of the joining surfaces of the two magnets to be joined, the magnetic fluxes from the N poles near the joining surface interfere with each other and are further distant in the vertical direction than in the case of FIG. 9 (a). Further, in FIG. 9 (c), a rectangular notch-shaped groove is formed in the longitudinal direction substantially at the center of the N pole on the upper side of the single magnet. Due to the repulsion of the N poles at the ends of the groove, the magnetic flux from the vicinity of the groove is far away in the direction perpendicular to the N pole surface.

Next, the effect of the structure of the present invention will be described with reference to FIG.

First, in the case of repulsion # 1, the width is 2 mm and the height is 3
This is a configuration in which two N magnets each having a diameter of 3 mm and a depth of 3 mm, which are the same magnetic poles, are forcibly joined to each other and are joined to a gap of 0.5 mm. A wheel element is joined to the lower side of the two magnets in the figure. The example of repulsion # 2 has a configuration in which two magnets are joined with a gap of 1 mm that is 0.5 mm wider than the configuration of repulsion # 1. The example of repulsion # 3 has a configuration in which a back yoke is provided in parallel on the S pole side of two magnets in which N poles are forcibly joined so that the same magnetic poles face each other as compared with the configuration of repulsion # 2. . In the example of repulsion # 4, compared to the configuration of repulsion # 3, the N pole side with respect to the two magnets is located above the two magnets in which the N poles having the same magnetic pole are forcibly joined. This is a configuration in which magnets are placed so as to face each other. The example of Repulsion # 5 showing the present invention is bonded 2 times as compared with the structure of Repulsion # 4.
The yoke 57 is provided in the gap between each magnet and the magnet placed on the upper side of the two magnets in the figure. The gear rotor used in the experiment has a diameter of 60 mm and 25 teeth.

Experimental data for the examples of Repulsion # 1 to Repulsion # 5 are shown in the graph of FIG. The horizontal axis of the graph is the bias magnetic flux (Gauss) when the air gap is 0.5 mm, and the vertical axis is the value obtained by dividing the magnetic flux change amount when the air gap is 0.5 mm by the bias magnetic flux.

In the above example of repulsion # 1, the bias magnetic flux is about 2
In the case of 100 Gauss, the rate of change in magnetic flux is approximately 0.136.
Is. In the example of repulsion # 2, when the bias magnetic flux is about 2200 gauss, the ratio of the magnetic flux change amount is about 0.178.
In the example of repulsion # 3, when the bias magnetic flux is about 2250 gauss, the ratio of the magnetic flux change amount is about 0.185. In the example of repulsion # 4, when the bias magnetic flux is about 2500 gauss, the rate of change in magnetic flux is about 0.22. On the other hand, in the case of Repulsion # 5 of the present invention, the ratio of the magnetic flux change amount is about 0.220 when the bias magnetic flux is about 2500 Gauss. As a result, the magnetic flux passing through the gear rotor of the vehicle speed detection device to which the present invention shown in the example of Repulsion # 5 is applied is improved, so that the detection accuracy of the rotation speed of the gear rotor can be improved.

According to the first to fourth embodiments described above, two magnets are used so that the N poles having the same magnetic pole face each other or the same magnetic poles are forcibly joined in parallel in the same direction. Since the magnetic flux is made to flow more and farther away, the magnetic flux passing through the magnetoelectric conversion element can be secured even if a small bias magnet is used. This allows
The pickup sensor can be downsized.

An application example of this embodiment is effective when there is a restriction on the space for mounting the sensor, such as a wheel speed sensor for detecting the number of rotations of the wheels of a bicycle. Further, since the magnet serving as the bias magnet can be downsized, an inexpensive rotation sensor can be realized.

[0065]

As described above, according to the first aspect of the present invention, two magnets are bonded with a predetermined gap by an adhesive so that the same magnetic poles face each other, and the same magnetic poles facing each other. A back yoke that is installed side by side on a magnetic pole different from
A magnetoelectric conversion element that is disposed adjacent to the extension of the gap where the two magnets are joined and that converts into a current by the change in the magnetic flux that is blown by the repulsion of the same magnetic poles facing each other of the two magnets; By providing a yoke for focusing the magnetic fluxes blown to the magnetoelectric conversion element on the magnetoelectric conversion element,
Since the magnets are forcibly joined and the repulsion of the same magnetic pole is used, the leakage magnetic flux can be flown farther.

The second invention is such that a rotating gear rotor, a yoke arranged to face a ridge and a valley of the gear rotor to condense a magnetic flux in a fixed direction, and both ends of each of the yokes. Adjacent to each other with an adhesive so that the same magnetic pole faces the extension of approximately the center between the magnetoresistive elements, which are arranged facing each other and whose resistance value changes due to the change of the magnetic flux. By providing two magnets and a back yoke arranged in parallel on the magnetic pole side different from the same magnetic pole facing each other, the rotational position of the gear rotor by at least two sets of two magnets can be determined. Since the detection is performed, the pickup sensor can be applied to increase the passage amount of the leakage magnetic flux and improve the detection accuracy of the rotation position of the gear rotor.

According to a third aspect of the present invention, two magnets are bonded together with an adhesive so that the same magnetic poles face each other with a predetermined gap, and the two magnets are arranged in parallel on the magnetic pole side different from the facing magnetic poles. Which is disposed adjacent to the back yoke and an extension of the gap where the two magnets are joined, and is converted into a current by the change in the magnetic flux that is blown by the repulsion of the same magnetic pole facing each other. A conversion element, a yoke for converging the magnetic flux blown to the magnetoelectric conversion element on the magnetoelectric conversion element, and the two magnets for the magnetoelectric conversion element on the extension of the gap where the two magnets are joined. Since the same magnetic pole of the two magnets and a magnet joined so that the same magnetic pole faces each other are provided on the opposite side through the magnetic flux generated by the repulsion of the same magnetic pole, the two magnets are connected to the magnetoelectric conversion element. Bonded to the other side through Since further repelled by the same poles of the magnets that can skip flux leakage in the direction of the magneto-electric conversion element more distant.

According to a fourth aspect of the invention, two magnets sandwiching a yoke in the gap so that the same magnetic poles face each other and joined by an adhesive, and the two magnets sandwiching the yoke are the same. A back yoke arranged in parallel with the magnetic pole different from the magnetic pole and an extension of the yoke sandwiched between the two magnets are arranged adjacent to each other, and are blown by the repulsion of the same magnetic poles facing each other of the two magnets. And a surface of the yoke sandwiched by the two magnets, and the yoke other than the surface of the yoke on the side of the magnetoelectric conversion element, and the magnetoelectric conversion element side. Since the magnetic flux is focused on the end portion on the side of the magnetoelectric conversion element by providing the nonmagnetic material having a shape that narrows down the end portion of the yoke, the leakage magnetic flux can be flown further in the direction of the magnetoelectric conversion element. You can

According to a fifth aspect of the present invention, two magnets are bonded with an adhesive so that the same magnetic poles are arranged in parallel and in the same direction with a predetermined gap, and an extension of the gap where the two magnets are joined. By including a magnetic sensitive element that is disposed adjacent to each other and is incorporated in a magnetoelectric conversion element that converts into a current by a change in magnetic flux skipped from the same magnetic pole of the two magnets, and a magnetic sensitive element that detects the skipped magnetic flux Since the same magnetic poles are arranged in parallel and the magnetic fluxes in the same direction interfere with each other, the leakage magnetic flux can be flown further away from the magnetic sensing element.

According to a sixth aspect of the present invention, a magnet in which a groove is formed in the same magnetic pole and an extension of the groove formed in the same magnetic pole of the magnet are arranged adjacent to each other, and the same groove is formed. Since the magnetic flux of the same magnetic pole in the groove interferes with each other because it is built in the magnetoelectric conversion element that converts into a current according to the change of the magnetic flux skipped from the magnetic pole and the magnetic sensitive element for detecting the magnetic flux skipped, the magnetic flux of the same magnetic pole in the groove interferes with each other. The leakage magnetic flux from can be made to fly further.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an overall configuration according to a first embodiment of a pickup sensor of the present invention and a vehicle speed detection device to which the pickup sensor is applied.

FIG. 2 is a diagram showing a modification of the first embodiment.

FIG. 3 is a diagram showing a manufacturing procedure of the first embodiment.

FIG. 4 is a sectional view showing an overall configuration according to a second embodiment of the present invention.

FIG. 5 is a plan view showing a pattern.

FIG. 6 is a sectional view showing an overall configuration according to a third embodiment of the present invention.

FIG. 7 is a sectional view showing an overall configuration according to a fourth embodiment of the present invention.

FIG. 8 is a diagram showing a modification of the fourth embodiment.

FIG. 9 is a diagram illustrating a leakage magnetic flux of a magnet.

FIG. 10 is a diagram showing an effect of the present invention.

FIG. 11 is a diagram showing experimental data relating to the present invention.

FIG. 12 is an explanatory view of partial cutting showing a conventional example.

FIG. 13 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 Magnetic pickup 5 Magnet unit 7, 9, 67, 69 Magnet 11 Adhesive 13, 15 Back yoke 19 Magnetoelectric conversion element 33a, 33b, 35a, 35b Magnetoresistive element 37 Gear rotor 63 Non-magnetic body 71 Magnetic sensing element 81 Groove 83 Edge Department

Claims (6)

[Claims] 1. A pair of magnets which are bonded with a predetermined gap by an adhesive so that the same magnetic pole faces each other, and a back yoke which is arranged in parallel on the magnetic pole side different from the facing magnetic pole of the two magnets. A magnetoelectric conversion element that is arranged adjacent to the extension of the gap where the two magnets are joined and that converts into a current by a change in the magnetic flux that is blown by the repulsion of the facing identical magnetic poles of the two magnets, A pickup sensor, comprising: a yoke that focuses the magnetic flux that is blown to the magnetoelectric conversion element on the magnetoelectric conversion element. 2. A rotating gear rotor, a yoke arranged to face a mountain and a valley of the gear rotor, respectively, for focusing magnetic flux in a fixed direction, and a yoke arranged to face each of both ends of the yoke. Two magnetoresistive elements which are provided and whose resistance value changes according to the change of magnetic flux, and which are bonded with a predetermined gap by an adhesive so that the same magnetic pole faces the extension of substantially the center between these magnetoresistive elements. And a back yoke arranged in parallel on different magnetic pole sides from the same magnetic poles facing each other, and a vehicle speed detecting device to which a pickup sensor is applied. 3. Two magnets which are bonded with an adhesive so that the same magnetic poles face each other with a predetermined gap, and a back yoke which is provided in parallel on the magnetic pole side different from the facing magnetic poles of the two magnets. A magnetoelectric conversion element that is disposed adjacent to the extension of the gap where the two magnets are joined and that converts into a current by a change in the magnetic flux that is blown by the repulsion of the same magnetic poles facing each other, A yoke for converging the magnetic flux blown to the magnetoelectric conversion element to the magnetoelectric conversion element, and an opposite side to the magnetoelectric conversion element on the extension of the gap where the two magnets are joined via the two magnets. To 2
A pickup sensor, comprising: the same magnetic pole of each magnet and a magnet joined so that the same magnetic pole faces each other. 4. Two magnets sandwiching a yoke in the gap so that the same magnetic pole faces each other and bonded by an adhesive, and a magnetic pole different from the same magnetic pole of the two magnets sandwiching the yoke. And a back yoke arranged in parallel on the side, and a change in magnetic flux which is disposed adjacent to the extension of the yoke sandwiched between the two magnets and is repulsed by the repulsion of the facing identical magnetic poles of the two magnets. And a surface of the yoke sandwiched by the two magnets, and the yoke other than the surface of the yoke on the side of the magnetoelectric conversion element, and the yoke of the yoke on the side of the magnetoelectric conversion element. A pickup sensor comprising: a non-magnetic material having a shape of narrowing an end portion. 5. Two magnets which are bonded with a predetermined gap by an adhesive so that the same magnetic poles are arranged in parallel and in the same direction, and are arranged adjacent to each other on the extension of the gap where the two magnets are joined. Is installed in the magnetoelectric conversion element that converts into a current by the change in the magnetic flux that is blown from the same magnetic pole of the two magnets,
A pickup sensor, comprising: a magnetic sensing element that detects the magnetic flux that is skipped. 6. A magnet in which a groove is formed in the same magnetic pole, and a magnet which is disposed adjacent to an extension of the groove formed in the same magnetic pole of the magnet and changes in the magnetic flux which is blown from the same magnetic pole in the groove. A pickup sensor, comprising: a magneto-sensitive element that is built in a magneto-electric conversion element that converts the magnetic flux into a magnetic field, and that detects the magnetic flux that is skipped.