KR100276941B1 - Magnetic sensor and its manufacturing method - Google Patents

Abstract

An object of the present invention is to improve the productivity of the product, and to provide an inexpensive magnetic sensor, which includes a substrate 4 and a magnetoelectric conversion element 5a for converting a change in the magnetic field provided on the substrate 4 into a voltage. ), A base 8 provided on the substrate 4, a magnet 9 arranged on the base 8 near the magnetoelectric conversion element 5a to generate a magnetic field, and adjacent to the magnet 9. The magnetic body 21 which adjusts the magnetic path of the magnetic field applied to the magnetoelectric conversion element 5a is provided.

Description

Magnetic sensor and its manufacturing method

The present invention relates to, for example, a magnetic sensor for detecting the rotational speed of a gear-shaped magnetic rotating body and a manufacturing method thereof.

(Conventional technology)

6 is a side cross-sectional view of a conventional magnetic sensor. 7 is an enlarged view of the main part of FIG. 6, wherein the magnetic sensor includes a sensor body 1, a casing 3 made of synthetic resin covering the sensor body 1, and a connector connected to the sensor body 1; Have (2)

The sensor main body 1 includes a substrate 4, a detector 5 fixedly mounted on the top end of the substrate 4 by soldering 15, and having a hall element 5a as a magnetoelectric conversion element embedded therein, and a substrate. The electronic component 6 mounted on the (4), the wiring 7 for electrically connecting the electronic component 6 and the detection body 5, and the connector 2 while being provided on the board 4 The base 8 which consists of synthetic resin which is integral with and the rectangular parallelepiped magnet 9 provided in the front-end | tip part of this base 8 are provided. In addition, the magnet 9 is bonded to the upper surface of the base 8 with an adhesive 11, and the substrate 4 is bonded to the lower surface of the base 8 with an adhesive 12.

In the magnetic sensor, the convex portion 10a and the concave portion 10b of the rotating body 10 are close to each other by the rotation of the gear-shaped rotating body 10 which is a magnetic body close to the magnetic sensor. Therefore, the direction of the magnetic flux from the magnet 9 applied to the hall element 5a in the detector 5 is changed. The Hall element 5a has a voltage proportional to the magnetic flux component density in the vertical direction with respect to the Hall element 5a (when the direction of the magnetic flux is directed in the direction of the rotating body 10, the positive voltage and the magnetic flux are the bases). 8), and the magnetic flux component density in the vertical direction with respect to the hall element 5a is changed by the approach of the convex portion 10a and the concave portion 10b. The voltage according to the change is output from the detector 5. The electrical signal is sent to a computer unit (not shown) so that the rotation angle of the rotating body 10 is detected.

Next, the relationship between the position of the detector 5 with respect to the magnet 9 and the output voltage of the detector 5 will be described. FIG. 8 (a) is a view for explaining the direction of magnetic flux generated in the magnet 9 when the convex portion 10a is opposed to the detector 5, and the position of X in FIG. 7 (detector 5). When the detector 5 is disposed on the rotating body 10 serving as the detected object), a path in which the magnetic flux is directed in the direction of arrow A in FIG. 8 (a) is constituted. On the other hand, when the detection body 5 is arrange | positioned at the position of VI of FIG. 7 (detecting body 5 is provided near the base 8), a magnetic flux will point to the direction of arrow B of FIG. 8 (a). The lost path is constructed. In the figure, it can be seen that the magnetic flux density of the vertical component becomes higher with respect to the Hall element 5a of the detector 5 at the side where the detector 5 is approached to the rotor 10. It is output from the detector 5.

8 (b) is a figure for explaining the direction of the magnetic flux which generate | occur | produces in the magnet 9 when the recessed part 10b opposes the detection body 5, and is a detection body in the position of Ⅶ of FIG. When (5) is arrange | positioned, the path | route which magnetic flux was directed to in the direction of arrow C of FIG. 8 (b) is comprised. On the other hand, when the detection body 5 is arrange | positioned at the position IV of FIG. 7, the path | route which magnetic flux was directed to in the direction of the arrow D of FIG. 8 (b) is comprised. In this figure, it can be seen that the magnetic flux density of the vertical component directed toward the base 8 with respect to the Hall element 5a of the detector 5 becomes higher when the detector 5 is separated from the rotor 10. Negative voltage as high as that is output from the detector 5.

9 shows the rotation angle of the rotating body 10 when the detecting body 5 is located at positions I, II, III, IV, V, VI and 의 of FIG. 7, and the detecting body at the rotating angle ( The operating characteristic curve of the detection body 5 which shows the relationship with the voltage output from 5) is shown. In this figure, when the output voltage is zero, that is, when the magnetic flux component in the vertical direction with respect to the hall element 5a is zero, the operating point of the detector 5 is the operating point of the detector 5, and the positive voltage value exceeding this operating point is a pulse wave. The electric signal converted into the pulse wave is sent to a computer unit (not shown), and the rotation angle of the rotating body 10 is detected.

In addition, when the detection body 5 is an operating point, the reference point at the end of the convex portion 10a will be in a position opposite to the detection body 5, but the rotational body 10 has a predetermined angle of rotation at that reference point. When it is within the allowable range L of, it is allowed to be within the detection accuracy range of the magnetic sensor. In the ninth aspect, the operating point of the detector 5 at positions I and V is within the allowable range L, and the magnetic sensors mounted at positions I and V are within the allowable detection accuracy.

In the magnetic sensor described above, as shown in FIG. 9, for example, when the detector 5 is installed at the position of Fig. 7, the rotor 10 when the power voltage of the detector 5 is zero is the operating point. The rotation angle of is separated from the allowable position L, and in order to obtain a predetermined detection degree, the detector 5 is set so that the rotation angle of the rotor 10 when the detector 5 is the operating point falls within the allowable range L. It is necessary to mount at the position of.

However, in the manufacturing process of the magnetic sensor, the magnet 9 is fixedly mounted on the upper surface of the base 8 by using an adhesive 11, and after the inverting of the base 8, the detector 5 is soldered ( A series of operations for fixing the substrate 4 fixed in advance by 15) using the adhesive 12 to the base 8 is performed manually, and the transverse direction between the magnet 9 and the detector 5 is performed manually. It was difficult to keep the relative position of. In addition, the magnet 9 and the detection body 5 may be fixedly mounted to the board | substrate 4 using the soldering 15 by the application amount of the adhesive agents 11 and 12. FIG. In addition, there was a variation in the operating point of the detector 5 itself.

Since the conventional magnetic sensor is configured as described above, it is difficult to manufacture the magnetic sensor by eliminating the factors that adversely affect the detection accuracy described above, and the product productivity of the magnetic sensor having a constant detection accuracy is poor. There was a problem that the manufacturing price is high.

The present invention has been made to solve such a problem, and an object thereof is to improve the productivity of a product and to obtain an inexpensive magnetic sensor and a method of manufacturing the same.

(Means to solve the task)

The magnetic sensor according to claim 1 of the present invention comprises a substrate, a magnetoelectric conversion element provided to be supported at an end portion on the substrate and converting the intensity of the magnetic field into a voltage, a base provided to support the substrate, and a vicinity of the magnetoelectric conversion element. And a magnet installed to be supported by the base to generate a magnetic field, and a magnetic body installed adjacent to the magnet to adjust a magnetic path of the magnetic field applied to the magnetoelectric conversion element.

In the magnetic sensor according to claim 2, the magnetic body is provided with a protrusion facing the magnetoelectric conversion element.

In addition, in the method of manufacturing a magnetic sensor according to claim 3, the operating characteristic of investigating the output change of the magnetoelectric transducer according to the relative position of the object to be detected and the magnetoelectric transducer before the final manufacturing process of the magnetic sensor for assembling the magnetic body and the case. A magnetic body that enables the desired operating characteristic is selected from a plurality of magnetic bodies having different sizes or shapes in accordance with the inspection result of this operating characteristic, and the selected magnetic body is assembled to manufacture a magnetic sensor.

1 (a) to 1 (d) are side cross-sectional views of the magnetic sensor of Embodiment 1 of the present invention.

FIG. 2 is an explanatory diagram showing the relationship between the rotation angle of the rotating body and the output voltage of the detector when the magnetic sensor of FIG. 1 is used.

3 (a) to 3 (d) are side cross-sectional views of the magnetic sensor of Embodiment 2 of the present invention.

4 is an enlarged view of a main part of FIG. 3 (c).

FIG. 5 is an explanatory diagram showing the relationship between the rotation angle of the rotating body and the output voltage of the detector when the magnetic sensor shown in FIGS. 3 (a) to 3 (d) is used.

6 is a side view of a conventional magnetic sensor.

7 is an enlarged view of the sixth main part.

8 (a) and 8 (b) are explanatory views showing the magnetic flux direction of the magnetic field applied to the detector in the magnet of FIG.

9 is an explanatory diagram showing the relationship between the rotation angle of the rotating body and the output voltage of the detecting body when the magnetic sensor shown in FIG. 6 is used.

* Explanation of symbols for main parts of the drawings

2: connector 3: case

5 detector 5a Hall element

8: base 9,33: magnet

21a-21d, 31a-31d: magnetic material 32: protrusion

Example 1

1 (a) to 1 (d) are side cross-sectional views showing examples of the magnetic sensor according to the first embodiment of the present invention, and FIG. 2 is a rotational angle of the rotating body and the detector when the magnetic body of FIG. It is a figure which shows the relationship of an output voltage.

The magnetic sensor shown in FIG. 1 (a) includes a sensor body 20, a case 3 made of synthetic resin covering the sensor body 20, and a connector 2 connected to the sensor body 20. Has)

The sensor body 20 is fixedly mounted to the substrate 4, the soldering portion 15 at the front end of the substrate 4, the detector 5 in which the Hall element 5a, which is a rotating element, is incorporated, and the substrate. A wiring (7) for electrically connecting the electronic component (6) mounted on the (4) and the detector (5), the base (8) formed on the substrate (4) and made of a synthetic resin integral with the connector (2); And a rectangular parallelepiped magnet 9 provided at the distal end of the base 8, and a magnetic body 21a provided adjacent to the magnet 9 to adjust a magnetic path from the magnet 9 in a rectangular parallelepiped shape.

The magnetic sensors shown in FIGS. 1 (b), 1 (c) and 1 (d) are magnetic bodies 21b, 21c and 21d having different sizes in place of the magnetic bodies 21a of the magnetic sensors shown in FIG. 1 (a). I'm using.

In addition, the magnet 9 and the magnetic bodies 21a, 21b, 21c, and 21d are bonded to each other using the adhesive 11 on the upper surface of the base 8, and the substrate 4 is attached to the lower surface of the base 8. It is bonded using (12).

In the magnetic sensor, the magnetic body is attached to the base 8, and the operation characteristic of the detection body 5 is inspected when the assembly before the final manufacturing process of the magnetic sensor for accommodating the sensor body 20 in the case 3. That is, the relationship between the rotation angle from the reference point of the rotating body 10 which is a to-be-detected body, and the output voltage of the detection body 5 at the rotation angle is calculated | required. As a result of the inspection, as shown in the example of FIG. 2, the operating characteristic curve of the detector 5 indicated by the symbol 'A' is obtained, and the rotation from the reference point of the rotor 10 when the detector 5 is the operating point is obtained. When it is found that the angle is not within the allowable range L, the length dimension of the rectangular parallelepiped prepared in advance is different, and the desired operating characteristics of the detector 5 can be desired among a plurality of magnetic bodies that adjust the magnetic path of the magnetic field generated by the magnet 9. Choose a magnetic material that allows you to That is, the magnetic body in which the rotation angle of the rotating body 10 when the detection body 5 is an operating point falls in the tolerance range L is selected.

The symbols 'B', 'C', 'D' and 'E' in FIG. 2 denote magnetic bodies 21a, 21b, 21c of FIGS. 1 (a) to 1 (d) for adjusting magnetic paths of the magnetic field generated in the magnet 9; Each characteristic curve of the detector 5 when 21d) is used. In the figure, the rotation angle of the rotating body 10 when the detecting body 5 is the operating point falls within the allowable range L, which is an operating characteristic curve of 'B' and 'C', and a detection having an operating characteristic of 'A'. As for the body 5, the magnetic body 21a or the magnetic body 21b may be selected.

Thereafter, the magnetic body 21 is manufactured by accommodating the selected body 21a or the body 21b attached to the base 8 in the case 3.

In addition, when the detection body 5 has a desired operating characteristic even without a magnetic body, the sensor body without the magnetic body assembled therein may be housed in the case 3 to manufacture the magnetic sensor.

In this way, the operating characteristic of the desired detection body 5 cannot be obtained due to the error in the relative mounting position between the magnet 9 and the detection body 5, the irregularity of the operating point of the detection body 5, and the like. When the rotational angle from the reference point of the rotating body corresponding to is not within the allowable range L, suitable magnetic bodies 21a, 21b, 21c, 21d are mounted adjacent to the magnet 9 and the desired detection body is adjusted by adjusting the magnetic path. The operating characteristic of (5) can be obtained.

In addition, as shown in FIG. 2, as the lengths of the magnetic bodies 21a, 21b, 21c, and 21d mounted adjacent to the rear surface of the magnet 9 become larger, the more magnetic flux of the magnetic field generated in the magnet 9 becomes the magnetic body 21a, 21b, 21c, 21d), the magnetic flux density directed toward the rotor 10 decreases, so that the value of the output voltage of the detector 5 is reduced, and the operating characteristics of the detector 5 are reduced. In selecting a magnetic material for adjustment, a magnetic material having a large length may be selected when adjustment is required to greatly reduce the output voltage of the detector 5.

In addition, adjustment of the operating characteristic of the detector 5 using the magnetic bodies 21a, 21b, 21c, and 21d is an adjustment when the necessity of lowering the output voltage of the detector 5 arises, and the detector 5 Is mounted close to the rotating body 10, it is not considered to adjust the operating characteristics of the detecting body 5, which is a case of approaching the detecting body 5 to the base 8 side. It is necessary to assemble and manufacture a magnetic sensor.

In addition, a magnetic body is not limited to the shape of a rectangular parallelepiped, For example, it may be a semicircle shape.

Example 2

3 (a) to 3 (d) are side sectional views showing respective examples of the magnetic sensor according to the second embodiment of the present invention, and FIG. 4 is a partially enlarged view of FIGS. 3 (a) to 3 (d). 5 is an operating characteristic curve of the detector, and reference numerals 'F, G, H, and I' indicate the operating characteristic curves of the magnetic sensors shown in FIGS. 3 (a) to 3 (d), respectively. .

In this magnetic sensor, magnetic bodies 31a, 31b, 31c, and 31d are provided adjacent to the cube-shaped magnets 33, respectively. The magnetic bodies 31a, 31b, 31c, and 31d have protrusions 32 which protrude so as to face the detector 5. The protrusion 32 is freely inserted into the recess 8a of the base 8.

In the present magnetic sensor, as shown in FIG. 4, the magnetic flux generated by the magnet 33 is attracted to the protruding portion 32 by the protruding portion 32, and is rapidly changing in the direction of the arrow E. The magnetic flux component density applied vertically becomes high, so that the large magnet 33 is not required as compared with the magnet 9 of the first embodiment, and the detector 5 can output a high voltage.

Further, compared with the operating characteristic curve of the first embodiment shown in FIG. 2, the rising curve at the operating point of the detector 5 becomes sharp, and the detection sensitivity is improved.

In addition, although the case where the Hall element 5a was used as a magnetoelectric conversion element was demonstrated in Example 1, 2, you may use a magnetoresistive element as a magnetoelectric conversion element.

As described above, according to the magnetic sensor of the present invention, the magnetic sensor of the present invention is provided on a substrate, a magnetoelectric conversion element for converting a change in the magnetic field installed on the substrate into a voltage, and a base provided on the substrate and the base in the vicinity of the magnetoelectric conversion element. Since a magnet generating a magnetic field and a magnetic body provided adjacent to the magnet to adjust the magnetic path of the magnetic field applied to the magnetoelectric conversion element are mounted, the mounting error of the relative position between the magnetoelectric conversion element and the magnet, the magnetoelectric conversion element itself Deterioration in detection accuracy due to irregularities in the operating point can be easily prevented, and the assembly work performance is improved because it is not necessary to spend a lot of time for adjusting the relative position between the magnetoelectric conversion element and the magnet.

In addition, when the protrusion is formed on the magnetic body facing the rotating element, the magnetic flux density of the vertical component applied to the detection body becomes high, the magnet generating the magnetic field can be miniaturized, and the detection sensitivity of the magnetic sensor is improved. do.

Further, according to the manufacturing method of the magnetic sensor of the present invention, before the final manufacturing process of the magnetic sensor for assembling the magnetic body and the case, the change of the output of the magnetoelectric transducer according to the relative position of the object to be detected and the magnetoelectric transducer is investigated. The operating characteristics are inspected, and a magnetic body that enables a desired operating characteristic is selected from a plurality of magnetic bodies having different sizes or shapes according to the result of the inspection of the operating characteristics, and the selected magnetic body is assembled so that the detection accuracy is outside the standard. The frequency of defective products can be greatly reduced.

Claims (3)

A substrate, a magnetoelectric conversion element installed to be supported at an end on the substrate to convert the strength of the magnetic field into a voltage, a base provided to support the substrate, and a magnetoelectric conversion element installed to be supported at the base near the magnetoelectric conversion element to generate a magnetic field. And a magnetic body disposed adjacent to the magnet and configured to adjust a magnetic path of the magnetic field applied to the magnetoelectric conversion element. The magnetic sensor as set forth in claim 1, wherein the magnetic body is provided with a protruding portion facing the magnetoelectric conversion element. A case, a substrate accommodated in the case, a magnetoelectric conversion element provided on the substrate for converting the intensity of the magnetic field into a voltage, a base provided on the substrate, and the base in the vicinity of the magnetoelectric conversion element and installed on the substrate. In the manufacturing method of a magnetic sensor comprising a magnet for applying a magnetic field to the device and a magnetic body provided adjacent to the magnet to adjust the magnetic path of the magnetic field, the final manufacturing of the sensor of the magnetic sensor to assemble the magnetic body and the case Before the step, an operation characteristic of the magnetoelectric conversion element that examines the output change of the magnetoelectric conversion element according to the relative position of the object to be detected and the magnetoelectric conversion element is inspected, and according to the result of the operation characteristic inspection, the size or shape A magnetic body that enables a desired operating characteristic is selected from the plurality of other magnetic bodies, and the selected magnetic body is selected. Method of manufacturing a magnetic sensor comprising the step of manufacturing a magnetic sensor by assembling.

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