JP3412276B2 - Rotation angle detector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel magnetic field rotating type rotating mechanism used as a sensor mechanism for detecting a throttle opening of an engine used for an automobile, a steering sensor detecting a rotational angle of a steering wheel, and the like. The present invention relates to an angle detection device.

[0002]

2. Description of the Related Art Various types of rotation angle sensors that constitute a rotation angle detection mechanism utilizing a magnetic field have been proposed in the past. FIG. 7 shows a basic structure of a rotation angle sensor utilizing such a magnetic field. First, in the example shown in FIG. 7A, a magnetoresistive element 51 is formed in a ring shape on a fixed substrate surface. Along with this, a permanent magnet that is rotated together with the object to be measured (not shown) with the central axis of the ring-shaped magnetoresistive element 51 as the axis of rotation.
52 is set. Then, the magnetic field generated by the permanent magnet 52 is applied to the ring-shaped magnetoresistive element 51 to change its resistance value, and the change in the resistance value between both ends of the magnetoresistive element 51 corresponds to the measured rotation angle amount. The rotation angle sensor of the magnet facing surface moving type is configured.

Further, as the rotation angle sensor, a magnetic field strength changing type is considered, and as this magnetic field strength changing type, there is a configuration as shown in FIG. That is, the substrate
Magnetic sensitive element 54 composed of magnetoresistive element pattern on 53
Is fixedly set, and the yoke 55 that is rotated together with the measured object is set so as to face the surface of the substrate 53, and the permanent magnet 56 is set for this yoke 55. In this case, the surface of the yoke 55 facing the substrate 53 is formed to be inclined, the distance between the yoke 55 and the magnetic sensitive element 54 is changed according to the rotation angle amount, and the magnetic field detected by the magnetic sensitive element 54 is changed. The amount of rotation angle is detected according to the strength.

However, in such a magnet facing surface moving type and magnetic field strength changing type rotation angle sensor, the relative position error between the magnetic sensing element and the magnet set to face it is a detection characteristic. On the other hand, it acts directly and greatly.

In order to deal with such a problem, (C)
A parallel magnetic field rotation type rotation angle sensor as shown in the figure is considered. That is, this rotation angle sensor has a yoke 5 having a pair of leg pieces 581 and 582 extending parallel to the axial direction so as to be integrally rotated with a shaft 57 that rotates together with the object to be measured.
8 and the permanent magnets 5 on the facing surfaces of the leg pieces 581 and 582, respectively.
Set 91 and 592. And this permanent magnet 591
The magnetic sensitive element 54 is fixedly set so as to intersect with the magnetic flux formed between the magnetic fields 592 and 592.

That is, in this rotation angle sensor,
A parallel equal magnetic field is set between the pair of permanent magnets 591 and 592, and the sensitivity element 54 is set in the parallel equal magnetic field. The influence of the relative position error with the element 54 is reduced, and it is effectively adopted as a rotation angle sensor that requires detection accuracy and durability.

FIG. 8 shows a conventional example of a rotation angle detecting device using such a parallel magnetic field rotation type rotation angle sensor, in which an input shaft 61 is made of a magnetic material, and one end of which is not shown. The rotation of the measuring body is coupled, an opening is formed along the axis on the other end surface, and permanent magnets 591 and 592 are bonded to the inner surface of the opening so as to face each other with the axis therebetween. That is, the yokes 581 and 582 are formed at the other end of the input shaft 61.

The input shaft 61 is rotatably supported by a housing 62 made of synthetic resin. The input shaft 61 is located at a position facing the end face where the permanent magnets 591, 592 of the input shaft 61 are set. The printed board 63 is attached so as to have a plane orthogonal to the axis of the input shaft 61.
Although not shown in detail, electronic circuit parts such as an amplifier circuit using a large number of electronic elements are mounted on the printed board 63, and a hall element 64 for angle detection is further provided.
Is attached.

The Hall element 64 is attached to and supported by the tip of a supporting member which is set perpendicularly to the surface of the printed board 63, and is a permanent magnet 591 attached to the input shaft 61.
And 592, that is, at a position corresponding to the axis of the input shaft 61. And housing 62
The opening of the portion where the printed board 63 is set is sealed by a cover 65 and packing.

However, the structure of the rotation angle detecting device constructed as described above requires a large number of parts, which increases the manufacturing cost. In order to reduce the number of parts, it is conceivable to integrate an amplifying circuit, an adjusting circuit, and the like, including a magnetic sensing element including a Hall element 64, as disclosed in Japanese Patent Laid-Open No. 2-285212.

When an amplifying circuit and an adjusting circuit are integrated with a magnetic sensitive element to form an IC chip, the magnetic sensitive element is formed by forming a pattern of a magnetic sensitive material on an insulating film. Since the electronic circuit element is constructed by combining the element and the same film on the same film, the direction of the film surface is parallel to the printed board. On the other hand, since the magnetic sensitive direction of the magnetic sensitive element is perpendicular to the film surface, an appropriate magnetic field (parallel magnetic field) cannot be applied from only one side of the film.

That is, in order to apply a parallel rotating magnetic field to this magnetic sensitive element, a magnetic circuit must be constructed so as to sandwich the printed board, and if the input shaft 61 is rotated, the print circuit is printed. Since the plate and the magnetic circuit interfere with each other, it is impossible to use the sensitivity element integrated into an IC in the structure shown in FIG.

As a method of adjusting the characteristics of such a magnetic sensing element, a plurality of resistors are set inside the integrated circuit, fuses are arranged in parallel with these resistors, and whether or not the fuses are blown is selected. Therefore, it is known to adjust the resistance value set in the circuit. However, in order to improve the accuracy of adjustment, a large number of terminals for adjustment are required, and the size of the integrated IC chip is also large. Therefore, it is necessary to pull out the adjustment terminal to the outside of the sensor including this IC chip. If so, the sensor body also becomes larger.

[0014]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, and enables the structure to be constituted by sufficiently simple components, and in particular, an amplifier circuit, an adjustment circuit and the like together with a magnetic sensing element. It is an object of the present invention to provide a rotation angle detecting device in which electronic circuit elements including the above are integrated and configured so that a parallel magnetic field rotating type magnetic field applying method can be effectively adopted.

[0015]

A rotation angle detecting device according to the present invention is a circuit element including a thin film magnetic sensitive element formed by patterning a magnetic sensitive material, and an amplifier circuit attached to the magnetic sensitive element. A sensing unit having a sensing unit having a built-in integrated IC chip unit is provided, the sensing unit is inserted to form a housing, and a pair of opposing permanent magnets that are rotated together with the rotating body to be measured are set. And a housing in which a parallel magnetic field is formed between the pair of yoke pieces, and the housing and the housing are combined. In the housing, the sensing portion of the sensing unit is arranged in a protruding peninsula-shaped portion, and in a state where the housing and the housing are combined, the peninsular portion in which the sensing portion is set is
Positions are set such that the magnetic fields intersect each other between the pair of yokes.

[0016]

In the rotation angle detecting device having such a structure, the internal functional parts constituting the sensor main body, for example, the circuit elements including the magnetic sensitive element and the amplifying circuit are integrated, and further, If necessary, it is integrated with a connector element and a lead frame with a resin to form a sensing unit, and the sensing unit is embedded in a housing to form a sensor body. In this case, the portion of the sensing unit that houses the magnetic sensing element is configured to project in a peninsular shape, and by combining the housing that houses the sensing unit and the housing that includes the yoke in which the permanent magnet is set, The magnetic sensitive element portion is arranged between the permanent magnets of the pair of yoke pieces, and the magnetic sensitive element portion is surrounded by the magnetic circuit. Here, the adjusting means is provided in the integrated circuit, for example, in the EPR.
It can be configured by incorporating an OM and a register, and if the input terminal to the EPROM is pulled out to the outside of the sensor main body for adjustment, the parallel magnetic field can be handled easily and can be configured with high accuracy. A rotation type rotation angle sensor mechanism can be used.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a cross-sectional configuration of a rotation angle detection device, which is configured to detect the rotation angle amount of a throttle valve 12 that constitutes a throttle valve member 11, for example. Therefore, the housing 13 that is integrally formed with the throttle member 11 has the input shaft that is integrally rotated with the throttle valve 12.
14 is set, and the input shaft 14 is connected to a rotating member 15 formed in the housing 13 and is driven in response to a depressing operation of an accelerator pedal (not shown).
The rotating member 15 is rotated integrally with the rotating member 15.

A yoke 16 made of a magnetic material is integrally attached to the rotating member 15.
The yoke 16 is provided with a pair of yoke pieces 161 and 162 which are opposed to each other with the axis of rotation interposed therebetween. And
Permanent magnets 171 and 172 are attached to the facing surfaces of the yoke pieces 161 and 162, respectively, by adhesion or the like so that a parallel magnetic field is set between them.
That is, the parallel rotating magnetic field that rotates with the rotation of the throttle valve 12 is set.

In this way, the rotary member to be measured integrated with the yoke 16
A housing 21 formed of a resin molded body is combined with a housing 13 that holds the rotatably 15, and a sensor body 22 is formed by the housing 21 portion. A sensing unit 23 is embedded and set inside the housing 21. This sensing unit
For example, as shown in FIG. 2, the reference numeral 23 includes an IC chip 24 in which a magnetic sensitive element and an EPROM and a register which constitute an amplifying circuit and an adjusting circuit thereof are integrated into one chip.

The IC chip 24 is mounted on a lead frame 25 which also serves as a wiring and a connector terminal of the sensor body 23.
The C chip 24 is appropriately connected by a bontig.
In the lead frame 25, the output terminal 251 and the adjustment terminal 252 as the sensor body 22 are formed in the subsequent process. Particularly, by mounting it by resin molding as shown by the broken line in FIG. ) The sensing unit 23 as shown in the figure is completed.

Here, the main body portion 231 of the sensing unit 23 in which the main portion of the lead frame 25 is embedded is formed in a flat plate shape, and an opening is formed corresponding to the IC chip 24 portion. The IC chip 24, which is located in the opening and is resin-molded together with the electronic circuit elements, is a magnetically sensitive IC.
The built-in portion 241 is set, and the IC built-in portion 241 is erected in a direction perpendicular to the plane of the main body portion 231. That is, by bending the lead piece connecting the IC chip 24 and the lead frame 25 at a right angle, in particular, the magnetic sensitive surface of the magnetic sensitive element set inside the IC built-in portion 241 has a sensing unit body. It should be set to be perpendicular to the part 231.

The sensing unit 23 configured as above
The housing 21 is formed by molding the resin into a main body 24.
The IC-embedded portion 242 rising vertically from the surface 1 is projected in a peninsular shape. In the state where the housing 21 is combined with the housing 13, the molded protruding peninsula portion 211 of the IC built-in portion 241 is arranged between the pair of yoke pieces 161 and 162 of the yoke 16. To be done. That is, the parallel magnetic fields between the permanent magnets 171 and 172 attached to the yoke pieces 161 and 162, respectively, are intersected with each other so that the magnetic sensitive surface of the magnetic sensitive element of the IC chip 24 is set.

FIG. 3A shows the sensor main body 22 taken out and shown. The sensor main body 22 is provided with a cylindrical portion 221 to which a peninsular portion 211 is provided at the center thereof. Further, FIG. 6B shows the yoke 16 arranged inside the housing 13 in an extracted manner. A pair of yoke pieces 161 and 162 are formed by bending a plate material made of a magnetic material into a U-shape.
Are formed. And this yoke piece 16
The permanent magnets 171 and 172 are bonded to the opposing surfaces of 1 and 162, and the coupling piece 16 that connects the yoke pieces 161 and 162 is used.
The three parts are integrated with a rotating member 15 that is connected to the input shaft 14.

In the rotation angle detecting device having such a structure, when the throttle valve 12 as the object to be inspected is rotated in response to the operation of the accelerator pedal or the like, the rotating member 15 is integrally formed with the throttle valve 12. Rotates, and the yoke 16 rotates accordingly. When the yoke 16 is rotated, the yoke piece 16
1 and 162 rotate with the permanent magnets 171 and 172 in the parallel plane, so that the parallel equal magnetic field rotates in the plane. Therefore, the magnetic field that traverses the peninsula part 211 having the IC built-in part 241 of the sensing unit 23 arranged between the permanent magnets 171 and 172 rotates.

Here, assuming that the parallel magnetic field set between the yoke pieces 161 and 162 of the yoke 16 is Ho and the rotation angle of the yoke 16 is θ, the IC set inside the peninsular part 211. The effective magnetic field H applied to the magnetic sensing element forming the chip 24 changes with H = Ho sin θ.

For example, when the magnetic sensing element is composed of a Hall element, the output voltage V from the magnetic sensing element is V = Vo sin θ due to the Hall effect (where Vo is “H = Ho”). Output voltage).

The method of adjusting the output characteristics and the like of the magnetic sensing element is based on the EPR integrated as an IC chip.
This is an adjustment by OM and a register, and by inputting a series of electric signals from the adjustment terminal 252, the slope (amplification degree) and offset (bias) which are the sensor output characteristics
To adjust.

In the rotation angle detecting device constructed as above, the magnetic sensing element which is an internal functional component of the sensor main body 22,
An IC chip 24 in which an amplifier circuit, an adjustment circuit, etc. are integrated,
A connector terminal composed of the output terminal 251 of the sensor body 22 and a lead frame 25 for wiring the connector terminal and the IC chip 24, which is formed by press working, are integrated as a sensing unit 23 by resin molding. . Therefore, the number of assembling steps for each of these parts is reduced.

Further, the sensing unit 23 thus integrated has a structure in which the housing 21 is formed by inserting the resin into the resin.
The number of assembling steps using 23 fixing parts such as screws is reduced, and at the same time, it is possible to reduce the number of components such as a cover and packing for sealing the opening of the electronic circuit assembly part with respect to the housing 21. The 23 fixed conditions are also very stable and highly durable.

Further, the IC chip built-in portion 241 including the magnetic sensing element of the sensing unit 23 is formed so as to project as the peninsula portion 211 in the housing 21.
This peninsula part 211 is arranged between the permanent magnets 271 and 272 of the yoke 16 in a state where the above is combined with the housing 13 connected to the subject. Therefore, a magnetic circuit that is less likely to be affected by an error in the relative position between the rotated permanent magnets 271 and 272 and the magnetic sensitive element is configured, and the “parallel magnetic field rotation type” can be effectively applied.

In addition, by incorporating an EPROM or a register in the IC chip 24 as the adjusting means, it is possible to adjust the output characteristics by using a terminal structure for adjusting several lines, and the terminals for this adjustment are By leading out to the outside of the sensor main body 22 via the lead frame 25, adjustment in the assembled state including the variation of the magnet is possible.

FIG. 4A shows another example of the sensing unit 23, and FIG. 4B shows a state in which the sensor unit 22 is formed by inserting the sensing unit 23 into resin. ing. That is, in the sensing unit 23 shown here, the output terminal 251 is connected to the IC built-in portion 241.
Is formed so as to extend to the side opposite to the IC built-in portion 241 so as to coincide with the extending direction of the connector, and a connector structure including an output terminal 251 on the side opposite to the coupling surface of the housing 21 with the housing 13. The body is formed.

FIG. 5 shows still another embodiment of the sensing unit 23. In this example, a first IC built-in portion 31 having a magnetic sensitive element, an amplifier circuit and the like built therein, and an adjusting circuit and the like are built therein. The second IC built-in portion 32 is configured by being divided into two, and both are attached to one lead frame. Then, when the first IC built-in portion 31 including the magnetic sensitive element is formed by being erected and resin-molded as the sensor main body to form the housing, the pair of permanent magnets of the pair of permanent magnets set in the yoke of the housing is formed. It is adapted to form peninsulas arranged between each other.

FIGS. 6A and 6B show a different embodiment of the sensing unit 23.
In the example shown in FIG. 9A, the lead-out lead of the IC built-in portion 241 and the lead frame 25 are separately prepared, and they are integrated by spot welding 35. Further, in the example of (B), the connector terminal 36 which is an output terminal and the lead frame 25 are separately prepared, and the spot welding 37 is performed between them.
It is integrated in this way. That is, in the example shown in FIG. 6, the lead terminal of the IC chip, the connector terminal, and the lead frame are separately prepared and connected by using spot welding means. The integrated sensing unit 23 is configured by.

[0035]

As described above, according to the rotation angle detecting device of the present invention, it is possible to construct the rotating angle detecting device with sufficiently simple components, and in particular, an electronic circuit including an amplifying circuit, an adjusting circuit, etc. together with the magnetic sensing element. The elements can be integrated and the parallel magnetic field rotation type magnetic field application method can be effectively adopted, and the manufacturing cost can be effectively reduced, and the detection accuracy can be easily ensured and highly reliable. it can.

[Brief description of drawings]

FIG. 1 is a sectional configuration diagram for explaining a rotation angle detection device according to an embodiment of the present invention.

FIG. 2A is a plan view for explaining a process of forming a sensing unit in the above embodiment, and FIG. 2B is a diagram showing a completed sensing unit.

FIG. 3A is a diagram showing the sensor body taken out, and FIG. 3B is a diagram showing the yoke portion taken out.

FIG. 4A is a diagram showing a second embodiment of the sensing unit, and FIG. 4B is a sectional view showing a sensor main body part in which the sensing unit is incorporated.

FIG. 5 is a diagram showing a third embodiment of the sensing unit.

FIGS. 6A and 6B are diagrams for explaining fourth and fifth examples of the sensing unit section, respectively.

FIG. 7A to FIG. 7C are diagrams illustrating a basic configuration example of a rotation angle sensor using a magnetic field.

FIG. 8 is a cross-sectional configuration diagram illustrating a conventional rotation angle detection device.

[Explanation of symbols]

11 ... Throttle valve member, 12 ... Throttle valve, 13 ... Housing, 14 ... Input shaft, 15 ... Rotating member, 16 ... Yoke, 161, 16
2 ... Yoke piece, 171, 172 ... Permanent magnet, 21 ... Housing, 211 ... Peninsula part, 22 ... Sensor body, 23 ... Sensing unit, 24 ... IC chip, 241 ... IC built-in part, 25 ... Lead frame.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-2-122205 (JP, A) JP-A-2-285212 (JP, A) JP-A-56-107119 (JP, A) JP-A-2- 205346 (JP, A) Actual Kaihei 5-14829 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01B 7/30 G01D 5/14

Claims (3)

(57) [Claims] 1. A thin film magnetic sensing element formed by patterning a magnetically sensitive material, and an IC chip portion in which circuit elements including an amplifier circuit attached to the magnetic sensing element are integrated and embedded in a resin. A sensing unit having a sensing unit, a housing made of resin configured by inserting the sensing unit, and a pair of opposing yoke pieces that are rotated together with the rotating body to be measured. A yoke configured to attach a magnet so that a parallel magnetic field is formed between the pair of yoke pieces, and a yoke that is attached to the yoke and constitutes a support for the rotating body to be measured, and is integrated with the housing. And a housing part that is combined with each other, and the sensing portion that incorporates the magnetic sensing element that constitutes the sensing unit is A peninsula portion projecting from the body of the unit in the form of a peninsula, wherein the housing and the housing are combined, the peninsula portion containing the sensing portion is located between the pair of yoke pieces. A rotation angle detecting device characterized in that the position is set in a parallel magnetic field. 2. The magnetic sensing element and the circuit element are embedded in resin to form the sensing section, and the sensing section is integrally coupled to a lead frame having a connector terminal. The sensing unit is configured such that the sensing unit is bent and continuous in a direction intersecting with, and the sensing unit rises from the surface of the lead frame and projects. The sensing unit is embedded in the housing. Has been
The rotation angle detecting device according to claim 1, wherein the peninsula portion is formed by a sensing portion. 3. The sensing section is made of a resin molded body containing an IC chip including the magnetic sensing element, and other circuit elements are embedded in a resin to form a circuit member section. The rotation angle detecting device according to claim 1, wherein the sensing unit is connected through a terminal member to configure the sensing unit, and the sensing unit is embedded in the housing.