JP5007459B2 - Sensor for detecting rotation angle - Google Patents

Description

  The present invention relates to a rotation angle detection sensor for detecting the position of a rotating body such as a rotor of a motor.

In a brushless motor, rectification control is performed by switching the direction of the current flowing through the stator. In order to perform this commutation control, it is necessary to obtain rotor angle information, and an angle sensor for detecting the rotor angle is provided.
As such an angle sensor, a method of detecting a magnetic field of a permanent magnet of a rotor such as a resolver or an increment type pulse encoder is generally adopted.

On the other hand, when fine control is required while further simplifying the configuration and reducing costs, a rotation angle detection sensor based on the principle of eddy current loss is preferably used. (For example, refer to Patent Document 1 and Patent Document 2).
In Patent Document 1 and Patent Document 2, a rotation angle detection sensor includes an encoder structure formed of a periodic conductor pattern formed on a rotating body and an inductance element arranged to face the encoder structure. Is configured.
In the rotation angle detection sensor of this configuration, by applying a signal current to the inductance element, the excited magnetic flux is passed through the encoder structure, and an eddy current loss is generated in the conductor pattern of the encoder structure.
The magnitude of this eddy current loss changes periodically due to the periodic change of the conductor pattern accompanying the rotation of the rotating body.
Therefore, the principle of detecting the angle information of the rotating body by performing arithmetic processing based on the eddy current loss is adopted.

German Patent Application Publication No. 20 2006 008 962 U1 German Patent Application Publication No. 103 20 941 A1 (Fig. 2 etc.)

In Patent Document 1, there is a description that the encoder structure of the rotation angle detection sensor is formed of, for example, aluminum, steel, copper, PCB (printed circuit board), conductive foil or the like.
However, since Patent Document 1 does not disclose a specific structure or manufacturing method of the encoder structure, the feasibility is poor.

  On the other hand, in Patent Document 2, as a specific form of the encoder structure, a form (FIG. 1b, FIG. 2d) formed into a conductor pattern in which the encoder structure is integrated, and a conductor pattern for each period are arranged separately. (Fig. 2e) is disclosed.

  When forming into a conductor pattern in which the encoder structure is integrated, for example, a method of cutting or punching from a plate-like member, a method of cutting a metal, a method of using a printed circuit board, or the like can be considered.

  Here, for example, as shown in FIG. 20A, a rotation angle detection sensor having a configuration in which an encoder structure 54 indicated by hatching in FIG. 20 is attached to a main surface 53 of a rotating body 52 that rotates around a rotating shaft 51. think of.

When the encoder structure 54 shown in FIG. 20A is punched into a desired pattern shape from a plate-like member and molded into an integrated conductor pattern, as shown in FIG. The material in the outer peripheral portion 57 and the inner peripheral portion 58 of the portion 56 punched for 54 cannot be reused as the punching material and remains.
Therefore, the material yield is extremely deteriorated.
Further, an expensive large mold is required for punching.

In addition, the method of cutting metal also has a problem that a large amount of material that is removed by cutting and is not used is produced, and that it takes time for cutting.
Furthermore, the method of using a printed circuit board has a problem that it takes time to process because a pattern is formed by etching.

  Therefore, when forming into a conductor pattern in which the encoder structure is integrated, there are problems such as an increase in the number of manufacturing steps and required time, and an increase in material cost and manufacturing cost.

  On the other hand, in the form (FIG. 2e) in which the conductor patterns for each period of Patent Document 2 are arranged separately, the conductor pattern for each period can be produced using the same mold. As a result, it is possible to improve the material yield by reducing the material to be removed, and to reduce the cost of the mold.

  However, in this embodiment, the space between the conductor patterns is blank, and the conductor patterns are not continuous. For this reason, since the eddy current is interrupted in this blank portion, detection with high resolution cannot be performed, and the detection accuracy of the rotation angle is lowered.

  In order to solve the above-described problems, the present invention provides a rotation angle detection sensor that can be easily manufactured, has excellent material yield, and can perform detection with good accuracy.

The rotation angle detection sensor of the present invention comprises a rotating body and a conductor pattern that is rotatably attached together with the rotating body, and includes an encoder structure in which the width dimension of the conductor pattern periodically changes, and a plurality of inductance elements. And a sensor body that is disposed opposite to the side on which the encoder structure of the rotating body is formed and is spaced. The encoder structure uses a phase member that constitutes at least one period of the periodic change in the width dimension of the conductor pattern, and a plurality of phase members having the same period and shape are brought into annular contact with each other. Thus, it arrange | positions in a rotary body and the longitudinal dimension of the air core part of an inductance element is formed larger than the maximum width dimension of a conductor pattern.

According to the rotation angle detection sensor of the present invention described above, the distance between the encoder structure in which the width dimension of the conductor pattern periodically changes and the side on which the encoder structure of the rotating body is formed , including a plurality of inductance elements. By having the sensor main body and the sensor main body arranged opposite to each other, a periodic change in the width dimension of the conductor pattern of the encoder structure can be detected through the inductance element of the sensor main body. And the rotation angle of a rotary body is detectable from this detection result.

Further, according to the rotation angle detection sensor of the present invention, the encoder structure has the same period and shape by using the phase member constituting at least one period of the periodic change in the width dimension of the conductor pattern. A plurality of phase members are arranged on the rotating body in a ring shape and in contact with each other. Thereby, compared to a case where the encoder structure is integrally and annularly formed from a base material having a specific size, the phase member can be easily manufactured by a simple configuration and manufacturing method, Moreover, the base material area can be used effectively. Further, even when the encoder structure is manufactured by electroforming or the like, the phase member can be manufactured with the minimum necessary raw materials.
That is, the encoder structure can be manufactured by effectively using the material.
Furthermore, since the plurality of phase members are arranged in contact with each other, the conductor pattern of the encoder structure can be formed continuously. Thereby, since the conductor pattern is not interrupted, the rotation angle can be detected with high resolution, and the rotation angle can be detected with high detection accuracy.

In the rotation angle detection sensor of the present invention, the rotating body is provided with a storage wall for storing the encoder structure, and the individual phase members of the encoder structure are stored in the storage portion between the storage walls. It is also possible.
By setting it as such a structure, a phase member can be easily accommodated in a storage part with a sufficient positional accuracy by a storage wall.

Furthermore, in this configuration, that is, a configuration in which the phase members are stored in the storage portion between the storage walls, each phase member may be in contact with the storage wall at at least three points.
Since each phase member is in contact with the storage wall at at least three points, the position of the phase member can be reliably fixed when two phase members are arranged on the storage wall.

Furthermore, when the adjacent phase members are brought into contact with each other to form an annular shape, it is possible to adopt a configuration in which an overlap margin is provided for the mutual phase members to overlap.
By setting it as such a structure, since the fitting with an adjacent phase member can be achieved at a high level by overlap, the encoder structure excellent in precision can be obtained.

  Furthermore, it is also possible to employ a configuration in which one end and the other end of the phase member are both formed in a straight line.

  Furthermore, a concave portion is formed at one end portion of the phase member, and a convex portion is formed at the other end portion. When the adjacent phase members are brought into contact with each other to form an annular shape, the concave portion and the convex portion are fitted. A configuration is also possible.

  In the rotation angle detection sensor of the present invention, the encoder structure may be formed on the main surface of the rotating body or may be formed on the outer peripheral surface of the rotating body.

According to the above-described present invention, the phase member can be easily manufactured with a simple configuration and manufacturing method, and therefore, the encoder structure including the phase member can be easily and inexpensively manufactured.
Thereby, manufacture of the rotation angle detection sensor can be facilitated, and the manufacturing cost can be reduced.
In addition, since the encoder structure can be manufactured by effectively using the material, the material yield is greatly improved.
Thereby, the material cost of the rotation angle detection sensor can be reduced.

  Furthermore, according to the present invention, the rotation angle can be detected with high resolution, and the rotation angle can be detected with high detection accuracy. Therefore, a rotation angle detection sensor with good detection accuracy can be realized.

As an embodiment of the present invention, a schematic configuration diagram of a rotation angle detection sensor is shown in FIGS. 1A and 1B. FIG. 1A shows a plan view and FIG. 1B shows a side view.
As shown in FIGS. 1A and 1B, a disk-shaped rotor 2 is attached to a rod-shaped rotating shaft 1.
The rotor 2 rotates around the rotation axis 1 as indicated by an arrow R in FIG. 1B.
In addition, an encoder structure 3 is formed on the surface of the rotor 2 using a conductor pattern.

And the sensor main body 4 of the sensor for rotation angle detection is provided facing the side in which the encoder structure 3 of the rotor 2 was formed.
The sensor body 4 has a fan shape along an arc centered on the rotation shaft 1. And the sensor main body 4 is being fixed by the member which is not shown in figure, and the encoder structure 3 of the rotor 2 is comprised so that a relative position with this sensor main body 4 may change.
The encoder structure 3 and the sensor body 4 constitute a sensor that detects the rotation angle of the rotor 2.

A plan view of the rotor 2 of FIG. 1 is shown in FIG. The details of the conductor pattern of the encoder structure 3 are shown in the plan view of FIG.
As shown in FIG. 2, the conductor pattern of the encoder structure 3 has a curved shape whose width changes in a trigonometric function with respect to the rotation angle of the rotor 2. When the rotor 2 rotates, the width of the conductor pattern of the encoder structure 3 periodically increases or decreases at a specific position.
In FIG. 2, a range corresponding to one phase (one period) of the periodic change in the width of the conductor pattern is also shown. Since six phases are formed in one rotation of 360 degrees, one phase is 60 degrees.

  As shown in FIG. 3, the conductor pattern of the encoder structure 3 changes in a trigonometric shape on the inner side and the outer side around a circle having a diameter D indicated by a chain line. As a result, the width W of the conductor pattern also changes in a trigonometric function. As the conductor pattern width W of the encoder structure 3 changes, the eddy current generated by the magnetic flux generated when a signal current is applied to the inductance element also increases or decreases. By calculating the inductance that changes due to the eddy current loss, the rotation angle θ of the rotor 2 can be detected.

As a material of the conductor pattern of the encoder structure 3, for example, a conductive material such as aluminum, steel, copper, silver, a wiring board, a conductive foil, or a plastic material containing a metal can be used. It is not necessary to use a magnetic material for the conductor pattern.
As a material of the rotor 2 in which the encoder structure 3 is disposed, an insulator such as plastic or a metal having a conductivity different from that of the encoder structure 3 such as iron can be used.
Although not shown, the encoder structure 3 can be integrally formed of the same material as the rotor 2. In this case, the pattern portion of the encoder structure 3 is configured to rise with a certain thickness with respect to the peripheral portion of the rotor 2.

  The diameter D of the pattern portion of the encoder structure 3 and the number of cycles (number of phases) n of the encoder structure 3 are preferably matched to conditions such as the configuration of the rotor 2 provided with the encoder structure 3 and the diameter size.

Next, a schematic configuration diagram (enlarged plan view of a main part) of the sensor body 4 is shown in FIG.
As shown in FIG. 4, four pattern coils C1, C2, C3, and C4 are formed on a substrate 11 such as a printed circuit board by a conductor having a square spiral shape.
Each of the pattern coils C1, C2, C3, and C4 forms an air core coil.
The four pattern coils C1, C2, C3, and C4 of the sensor body 4 constitute a first coil C1, a second coil C2, a third coil C3, and a fourth coil C4.

Next, FIG. 5 shows a state in which the coils C1, C2, C3, and C4 and the conductor pattern of the encoder structure 3 are opposed to each other.
The coils C1, C2, C3, and C4 are arranged at intervals of ¼ period (phase difference 90 °) of the periodical change in the width of the conductor pattern of the encoder structure 3. That is, the first coil C1, the second coil C2, the third coil C3, and the fourth coil C4 are arranged in this order so as to have a phase difference of 90 °.
Thereby, the second coil C2 and the fourth coil C4 are arranged with a phase difference of 90 ° with respect to the first coil C1 and the third coil C3.

The first coil C1 and the third coil C3 form a 180 ° phase angle offset, and the second coil C2 and the fourth coil C4 form a 180 ° phase angle offset.
Thereby, a signal such as a differential signal can be generated, and the absolute position of the rotor 2 can be detected using this signal. It is also possible to detect the movement direction of the conductor pattern of the encoder structure 3, that is, the rotation direction (clockwise or counterclockwise) of the rotor 2.

  The longitudinal dimension L of the air core part of each coil C1, C2, C3, C4 is formed larger than the maximum width dimension Wmax of the conductor pattern of the encoder structure 3. With such a dimensional relationship, when magnetic flux is generated from the coils C1, C2, C3, and C4, the degree of generation of eddy current generated in the encoder structure 3 is set to a size corresponding to the longitudinal dimension L described above. Therefore, the detection accuracy can be improved.

In this embodiment, in particular, as shown in FIGS. 1 to 3, the encoder structure 3 includes 6 parts 5 corresponding to one period (one phase) of a periodic change in the width dimension of the conductor pattern. It is configured using pieces.
Hereinafter, this part is defined as the phase member 5.
Each phase member 5 has the same period and shape, and is in contact with the adjacent phase member 5 at the narrowest portion of the conductor pattern.
And the encoder structure 3 is comprised by arrange | positioning the six phase members 5 cyclically | annularly along the periphery (not shown) centering on the rotating shaft 1. FIG.

  As the material of the phase member 5, the conductive pattern material described above, for example, conductive material such as aluminum, steel, copper, silver, wiring board, conductive foil, or plastic material containing metal can be used.

As a method of attaching each phase member 5 to the rotor 2, for example, a method of bonding with an adhesive, a method of brazing, a method of bonding with an adhesive sheet, or the like can be employed.
Further, in order to make uniform changes in the inductance of the coils C1, C2, C3, and C4 due to the eddy current in the conductor pattern, it is necessary to electrically join the contacted phase member 5 over the entire joining surface. There is. As a method of electrically joining the contacted phase members 5, a method of brazing using a silver solder or the like, a method of joining by laser welding, or the like can be employed.

In this configuration, the thickness of the phase member 5 can be set to 0.2 mm, for example.
Here, when setting the thickness of the encoder structure 3 / phase member 5, which is one of the conditions for ensuring excellent sensor accuracy, when the signal current is applied to the inductance element, the phase member 5 is It is necessary to know the depth of the eddy current that is excited.
For example, when a material having high conductivity such as copper (Cu), aluminum (Al), or silver (Ag) is used for the phase member 5, an eddy current of a thickness of 0.1 mm is obtained by simulation. The result that excitation can fully be performed is obtained.
Therefore, if the thickness of the encoder structure 3 / phase member 5 is 0.1 mm or more, sufficient sensor accuracy can be ensured. However, in the present embodiment, when the phase member 5 is manufactured by punching or cutting the plate-like conductive member, the thickness is set to 0. 0 to ensure an appropriate base material strength. 2 mm.
However, since the magnitude (depth) of the eddy current excited by the magnetic flux from the inductance elements such as the coils C1, C2, C3, and C4 also changes depending on the resistance value of the material of the phase member 5 of the encoder structure 3. The thickness of the phase member 5 is not limited to 0.2 mm or 0.1 mm, and a simulation based on the material used for the encoder structure 3 may be performed and appropriately adjusted according to the result.

According to the above-described embodiment, the encoder structure 3 uses the phase member 5 that constitutes one period of the periodic change in the width dimension of the conductor pattern, and uses six phases having the same period and shape. The members 5 are arranged on the rotor 2 in a ring shape and in contact with each other.
Thereby, compared with the case where the encoder structure 3 is integrally and annularly formed from a base material having a specific size, the phase member 5 can be easily manufactured with a simple configuration and manufacturing method. In addition, the base material area can be effectively utilized. Further, even when the encoder structure 3 is produced by electroforming or the like, the phase member 5 can be produced with a minimum necessary raw material.
That is, the encoder structure 3 including the phase member 5 can be manufactured by effectively using the material.

As described above, the phase member 5 can be easily manufactured with a simple configuration and manufacturing method, and therefore the encoder structure 3 including the phase member 5 can be easily and inexpensively manufactured.
Thereby, manufacture of the rotation angle detection sensor can be facilitated, and the manufacturing cost can be reduced.
In addition, since the encoder structure 3 can be manufactured by effectively using the material, the material yield is dramatically improved.
Thereby, the material cost of the rotation angle detection sensor can be reduced.

Furthermore, according to the present embodiment, the adjacent phase members 5 are arranged in contact with each other, so that the conductor pattern of the encoder structure 3 can be formed continuously. Thereby, since the conductor pattern is not interrupted, the eddy current generated in the conductor pattern by the coils C1, C2, C3, C4 of the sensor body 4 is not interrupted.
Therefore, the rotation angle can be detected with high resolution, and the rotation angle can be detected with high detection accuracy, so that a rotation angle detection sensor with good detection accuracy can be realized.

  The rotation angle detection sensor of the present invention, such as the configuration of the rotation angle detection sensor of the above-described embodiment, can be applied to various rotating bodies to detect the rotation angle.

For example, the rotation angle of the rotor of the motor can be detected by applying to a permanent magnet synchronous motor.
In this case, an encoder structure composed of a conductor pattern whose width periodically changes is formed on the surface of the rotor of the motor, and a sensor body provided with an inductance element such as a coil is disposed opposite the encoder structure.
Preferably, the number of magnet pairs of the rotor of the motor is the same as the number of conductor patterns of the encoder structure. By configuring in this way, it is possible to obtain fine angle information necessary for controlling the rotational operation of the motor, and as a result, there is an advantage that the rotational control of the motor can be finely performed. .

In the above-described embodiment, the encoder structure 3 including the plurality of phase members 5 is formed on the main surface of the rotor 2.
On the other hand, for example, a groove can be formed in the rotor 2 and the encoder structure 3 can be formed inside the groove. The case is shown below.

As another embodiment of the present invention, schematic configuration diagrams of a rotational angle detection sensor in which an encoder structure 3 is formed in a groove formed on the main surface of the rotor 2 are shown in FIGS. 6A and 6B. 6A shows a plan view of the rotor 2 and the encoder structure 3, and FIG. 6B shows a cross-sectional view of the rotor 2 and the encoder structure 3.
6A and 6B, the sensor main body 4 is not shown, but the sensor main body 4 is disposed opposite to the encoder structure 3 as in FIGS. 1A and 1B.

In this embodiment, as shown in FIGS. 6A and 6B, a groove 6 is formed concentrically on the main surface of the disc-like rotor 2, and a plurality of phases are formed inside the groove 6. An encoder structure 3 comprising a member 5 is provided. Each phase member 5 of the encoder structure 3 is in contact with the wall surface 7 of the groove 6 at the maximum width.
That is, in this configuration, the phase member 5 of the encoder structure 3 is accommodated in the accommodating portion between the wall surfaces 7 of the groove 6. Hereinafter, the wall surface 7 of the groove 6 is referred to as a storage wall 7 for storing the phase member 5.
The groove 6 of the rotor 2 can be formed by, for example, lathe processing.

By configuring the rotation angle detection sensor in this manner, the rotation angle detection sensor can be easily manufactured as in the configuration of the previous embodiment in which the phase member 5 is disposed on the main surface of the rotor 2. Manufacturing costs and material costs can be reduced.
In addition, the conductor pattern of the encoder structure 3 can be formed continuously to realize a rotation angle detection sensor with good detection accuracy.

Further, in the present embodiment, the phase member 5 of the encoder structure 3 is disposed in the storage portion between the wall surfaces (storage walls) 7 of the groove 6, so that the phase member 5 is used by using the storage wall 7 as a guide. It can be easily stored in the storage unit and arranged in an annular shape.
Moreover, each phase member 5 can be arrange | positioned with sufficient precision because the phase member 5 is contacting the wall surface (storage wall) 7 in the part with the largest width | variety.

The arrangement state of the phase member 5 of this form is schematically shown in the plan view of FIG. In FIG. 7, the phase member 5 formed in an annular shape along the circumference of the storage wall 7 is depicted as being converted into a straight line.
As shown in FIG. 7, each phase member 5 is in contact with the storage wall 7 at a wide portion at the center, and is in contact with the adjacent phase member 5 at narrow portions at both ends. The phase member 5 is in contact with the storage wall 7 at two points.
Since the phase member 5 is configured in this manner, the shape of the phase member 5 is very simple. Therefore, the design is easy and the productivity is excellent.

In the form shown in FIG. 6, the groove 6 is formed, and the inside thereof is used as a housing portion for the phase member 5.
On the other hand, as shown in FIG. 8 which is a cross-sectional view of the rotor 2 and the encoder structure 3, a protrusion 8 is formed on the main surface of the rotor 2, and a portion between the wall surfaces (storage walls) 7 of the protrusion 8 is formed. May be used as a storage portion for the phase member 5.
Also in this case, the same effect as the case where the inside of the groove 6 is used as the accommodating portion of the phase member 5 can be obtained.

  In FIG. 8, the protrusion 8 is formed integrally with the rotor 2 by the same member. However, a member that becomes the protrusion 8 is formed separately from the rotor 2, and this member is attached to the rotor 2. The protrusion 8 may be configured.

Subsequently, some other forms of the phase member 5 constituting the encoder structure 3 will be described.
Hereinafter, each form is demonstrated with reference to the schematic top view drawn linearly similarly to FIG.

First, in the form shown in FIG. 9, both ends of each phase member 5 are wide portions, the wide portions are in contact with the storage wall 7, and the center is a narrow portion. The left and right ends (edges) of the phase member 5 are all formed in a straight line. The phase member 5 is in contact with the storage wall 7 at four points.
In the form shown in FIG. 7, when the phase members 5 are arranged in the storage wall 7, all the phase members 5 are annularly arranged in order to come into contact with the storage wall 7 at two points in the arcuately curved portion. In the previous stage, each phase member 5 may rotate, and there is a possibility that it takes time to arrange.
On the other hand, in the present embodiment shown in FIG. 9, two or more phase members 5 are arranged on the storage wall 7 by bringing the phase member 5 and the storage wall 7 into contact with each other at four or more points. As a result, the phase member 5 can be reliably fixed in position.
By the way, as in the present embodiment, when the four-point contact is used, no deviation occurs at the stage where one phase member 5 is arranged on the storage wall 7.

The form shown in FIG. 10 changes the shape of the right and left ends of the phase member 5 from the form shown in FIG. That is, the left and right edges are shaped like a puzzle piece, with the center portion protruding in a circular shape on the right side from the straight line in FIG. Thereby, the recessed part is formed in the left edge part of the phase member 5, and the convex part is formed in the right edge part.
In the present embodiment, the portion that contacts the storage wall 7 in the center and both ends of the phase member 5 is the same as that shown in FIG. 9, so the phase member 5 contacts the storage wall 7 at four points. is doing.
Accordingly, as in the embodiment shown in FIG. 9, no shift occurs at the stage where one phase member 5 is arranged on the storage wall 7.
Moreover, since the recessed part and convex part of the right and left edge part of the phase member 5 are fitted with the adjacent phase member 5, the positioning of the phase member 5 can be performed with high accuracy.
Furthermore, compared to the configuration shown in FIG. 9 in which the left and right edges are straight, it is less likely to cause a lateral shift in the direction perpendicular to the storage wall 7 between the adjacent phase members 5, and the encoder structure 3 is more accurate. The phase member 5 can be arranged.
Incidentally, as in the embodiment shown in FIGS. 1 to 3, when the encoder structure 3 is provided in an annular shape on the main surface of the rotor 2, the lateral displacement direction of the phase member 5 is the radial direction of the rotor 2. become. When the phase member 5 is laterally displaced in the radial direction of the rotor 2, a step is formed on the outer peripheral side and the inner peripheral side at a portion where the phase member 5 contacts.

The form shown in FIG. 11 is different from the form shown in FIG. 9 in the shape of the left and right ends of the phase member 5. That is, the left and right edges are shaped so that the front half protrudes from the straight line in FIG.
In this embodiment, since the front half of the left and right edges of the phase member 5 protrudes to the right side in the figure, the left front side of the phase member 5 does not contact the storage wall 7. That is, the phase member 5 is in contact with the storage wall 7 at three points.
Accordingly, if two or more phase members 5 are arranged on the storage wall 7, there is an effect that the phase members 5 can be reliably fixed in position.

The form shown in FIG. 12 changes the shape of the right and left ends of the phase member 5 from the form shown in FIG. That is, the left and right end edges are changed from a straight line perpendicular to the storage wall 7 in FIG. 9 to an oblique straight line with respect to the storage wall 7, and the front side of the end edge protrudes to the right.
In this embodiment, since the near side of the left and right edges of the phase member 5 protrudes to the right, the left front side of the phase member 5 does not come into contact with the storage wall 7 as in the embodiment shown in FIG. That is, the phase member 5 is in contact with the storage wall 7 at three points.
Accordingly, if two or more phase members 5 are arranged on the storage wall 7, there is an effect that the phase members 5 can be reliably fixed in position.

13A shows a plan view, and FIG. 13B shows a cross-sectional view in that each phase member 5 is formed with an overlap margin 9 for overlapping a part with the adjacent phase member 5. It is different from each form shown above.
In each phase member 5, as shown in FIG. 13B, the right edge is formed only in the upper half, and the left edge is formed only in the lower half, resulting in an overlap margin 9. Thereby, in the overlap allowance 9, the left phase member 5 is joined so as to overlap the right phase member 5.
In this embodiment, since the phase member 5 is in contact with the storage wall 7 at four points, no shift occurs at the stage where one phase member 5 is disposed on the storage wall 7.
By configuring in this way, the placement accuracy of the individual phase members 5 and the storage walls 7 can be maintained at a high level, and the fitting with the adjacent phase members 5 can be achieved at a high level. As a result, the encoder structure 3 with excellent accuracy can be obtained.

14A shows a plan view and FIG. 14B shows a cross-sectional view in which the configuration of the overlap margin 9 is changed from the form shown in FIGS. 13A and 13B.
In each phase member 5, as shown in FIG. 14B, one of the upper half and the lower half is formed at both the left and right end edges, and the other is not formed at both the left and right end edges at the overlapping portion 9. That is, it has a substantially T-shaped cross section. Accordingly, the phase member 5 having a substantially T-shaped cross section can be joined in the order of front, back, front, and back, and can be overlapped at the overlap margin 9.
However, since the front and back are alternately joined in this way, the number of phase members 5 needs to be an even number.
In this embodiment, since the phase member 5 is in contact with the storage wall 7 at four points, no shift occurs at the stage where one phase member 5 is disposed on the storage wall 7.
In addition, the placement accuracy of the individual phase members 5 and the storage walls 7 can be maintained at a high level, and the fitting with the adjacent phase members 5 can be achieved at a high level. An excellent encoder structure 3 can be obtained.

Here, considering the case where an adhesive is used when binding the phase member 5 to the rotor 2, the phase member 5 shown in FIGS. 7 and 9 to 12 is between the phase members 5 adjacent to each other. In this configuration, there is a slight gap. Accordingly, the adhesive is likely to permeate to the vicinity of the surface of the phase member 5 through the gap, and there is a possibility that the bonding state and workability when brazing the phase members 5 to each other are deteriorated.
On the other hand, the phase member 5 according to each form of FIG. 13 and FIG. 14 can suppress the penetration of the adhesive at the portion of the overlap margin 9, and as a result, the brazing between the phase members 5 is excellent. It can be said that it is excellent in that it can be done.

In each form shown in Drawing 7 and Drawing 9-Drawing 12, thickness of phase member 5 can be 0.2 mm, for example.
However, even in these forms, the thickness of the phase member 5 is not limited to 0.2 mm, and is thinner than 0.2 mm depending on the resistance value of the material of the phase member 5 and the appropriate selection of the manufacturing process. Alternatively, it can be thickened.

In each form shown in FIG.13 and FIG.14, the thickness of the phase member 5 can be 0.4 mm, for example because the phase member 5 has a level | step difference.
However, even in these forms, the thickness of the phase member 5 is not limited to 0.4 mm, and is thinner than 0.4 mm depending on the resistance value of the material of the phase member 5 and the appropriate selection of the manufacturing process. Alternatively, it can be thickened.

  In addition, the structure which provides the overlap margin 9 in the edge of the phase member 5 like each form shown in FIG.13 and FIG.14 is fundamentally the phase of each form shown in FIG.7 and FIGS.9-12. The present invention can also be applied to the member 5.

  In the drawings of the above-described embodiments, for convenience, the phase member 5 and the storage wall 7 are linearly represented. However, in actual manufacturing, the shape / Needless to say, the dimensions may be set.

The phase member 5 of the encoder structure 3 in the present invention can be manufactured by the following method.
(1) A punching press process from a conductive metal plate member is performed. This method can be applied to each embodiment shown in FIGS. 7 and 9 to 12. According to this method, it is excellent in mass productivity and a phase member can be manufactured at low cost.
(2) After the pressing in (1), crushing is performed by a press machine or the like. This method is applicable to each form shown in FIG. 13 and FIG. 14 (form provided with overlap margin 9). Overlapping margin 9 is formed at the end of phase member 5 by crushing.
(3) The conductive metal is cut with a mill. This method can be applied to each embodiment shown in FIGS. 7 and 9 to 12. According to this method, it is excellent in mass productivity and a phase member can be manufactured at low cost.
(4) After the cutting process of (3), crushing is performed by a press machine or the like. This method is applicable to each form shown in FIG. 13 and FIG. 14 (form provided with overlap margin 9). Overlapping margin 9 is formed at the end of phase member 5 by crushing.
(5) Electroforming the conductive metal. This method can be applied to any of the forms shown in FIGS. 7 and 9 to 14. According to this method, it is possible to manufacture a phase member that is excellent in mass productivity and has high dimensional and shape accuracy.
(6) Injection molding is performed using a mixture of conductive metal powder and resin (preferably thermosetting resin). This method can be applied to any of the forms shown in FIGS. 7 and 9 to 14. According to this method, since the mass productivity is excellent and the moldability is excellent, the phase member 5 having a complicated shape can be easily produced.

  As a method for fixing the rotor 2 and the phase member 5, methods such as an adhesive, brazing, and an adhesive sheet can be employed.

As a method for electrically joining adjacent phase members 5, various known methods can be employed.
For example, the phase member 5 can be electrically joined by soldering in addition to the aforementioned laser welding or brazing using silver solder.

  The grooves 6 and the protrusions 8 constituting the storage wall 7 can be formed by a cutting means such as a lathe process. Lathe machining is a machining method in which cutting is performed by applying a cutting blade while rotating a rotating body such as the rotor 2.

  By the way, in embodiment shown in FIGS. 1-3, although the encoder structure 3 which consists of the phase member 5 was provided in the main surface of the disk-shaped rotor 2, the encoder structure 3 is provided in the side surface etc. of a rotor. It is also possible to provide. The case is shown below.

FIG. 15 is a perspective view of a configuration of a rotation angle detection sensor in which the rotor 2 is formed in a substantially cylindrical shape and the encoder structure 3 is provided on the side surface (outer peripheral surface). The figure on the left side is an exploded view of the sensor body 4 and the rotor 2, and the figure on the right side is an assembled view of the sensor body 4 and the rotor 2.
The phase member 5 of the encoder structure 3 has a shape that is in contact with the adjacent phase member 5 at a narrow portion, as in the embodiment shown in FIGS.
In this configuration, since the encoder structure 3 is formed directly on the outer peripheral surface of the rotor 2 and the sensor body 4 may be installed so as to face the encoder structure 3, the installation of the sensor body 4 is extremely easy. Has advantages.

FIG. 16 is a perspective view showing the configuration of a rotation angle detection sensor in which the rotor 2 is formed of a disk and a cylinder, and the encoder structure 3 is provided on the inner peripheral surface of the cylinder. The figure on the left side is an exploded view of the sensor body 4 and the rotor 2, and the figure on the right side is an assembled view of the sensor body 4 and the rotor 2.
The phase member 5 of the encoder structure 3 has a shape that is in contact with the adjacent phase member 5 at a narrow portion, as in the embodiment shown in FIGS.
In this configuration, the sensor main body 4 can be arranged inside the rotor 2, so that there is an advantage that it is not necessary to increase the axial length of a motor or the like in order to arrange the sensor main body 4. .

15 and 16 can be modified to accommodate the phase member 5 of the encoder structure 3 in a storage portion between the storage walls 7 such as grooves and protrusions.
As one form, the configuration shown in FIG. 15 is modified so that the phase member 5 of the encoder structure 3 is accommodated in the accommodating portion between the accommodating walls 7 on the side wall of the groove in the perspective view of FIG. Show.
As shown in FIG. 17, a groove is formed on the side surface of the rotor 2, and the side wall of the groove is a storage wall 7. The phase member 5 of the encoder structure 3 is disposed in contact with the inside of the storage wall 7.

In each structure shown in FIGS. 15-17, since the encoder structure 3 which consists of the phase member 5 is provided in the outer peripheral surface or inner peripheral surface of the rotor 2, the phase member 5 is not flat form, but an outer peripheral surface or It is necessary to make the shape along the curved surface of the inner peripheral surface.
In this case, for example, the phase member 5 is pressed and plastically deformed until a desired curved shape is obtained to obtain a curved shape along the curved surface.
For example, as shown in the plan view of FIG. 18A and the side view of FIG. 18, the side member of FIG. The phase member 5 has a curved shape. Thereby, the phase member 5 in the case of providing the encoder structure 3 on the outer peripheral surface or inner peripheral surface of the rotor 2 can be easily manufactured. Further, even when the surface to which the phase member 5 of the rotor 2 is attached is not smooth and has irregularities, the phase member 5 corresponding to the surface can be produced.

  In addition, by using a method of injection molding a mixture of conductive metal powder and resin as a method for manufacturing the phase member 5, the phase member 5 can be formed into a curved shape at the molding stage.

Although not shown, even when punching from a metal plate, a large number of phase members 5 can be punched from a single metal plate, and waste of materials can be greatly reduced.
Even in the case of molding, the mold for molding can be downsized, and the mold can be configured at low cost.

In each of the above-described embodiments, one phase member 5 forms one phase of the encoder structure 3, but one phase member may form two or more phases of the encoder structure 3. I do not care.
However, one phase member is ½ or less of the entire circumference of the encoder structure 3. Then, an encoder structure is constituted by a plurality (two or more) of phase members.

7, 8, and 17, the heights of the grooves 6 and the protrusions 8 are substantially equal to the thickness of the phase member 5 of the encoder structure 3, but are different from the thickness of the phase member 5. It doesn't matter.
More preferably, the height of the groove 6 or the protrusion 8 is set to be equal to or less than the thickness of the phase member 5. The groove 6 and the protrusion 8 may function as a guide for arranging the phase member 5, and if the height of the groove 6 or the protrusion 8 is larger than the thickness of the phase member 5, it interferes with the inductance element of the sensor body 4. This is because there is a risk that it will occur.

  In the sensor body 4 of FIGS. 4 and 5, the coils C1, C2, C3, and C4 are used to configure the sensor inductance element. However, in the present invention, the sensor is configured using an inductance element other than the coil. It doesn't matter.

  4 and 5, the four inductance elements made of coils are arranged. However, in the present invention, the number of inductance elements provided in the sensor body is not limited to four. Any number of two or more may be used.

In addition, the shape of the conductor pattern of the encoder structure composed of phase members is not limited to the curve shape (sine curve) that changes to a trigonometric function as in the above-described embodiments, but other curve shapes, Or it is good also as a shape which changes linearly like a rhombus or a triangle.
In addition to a configuration in which the width changes continuously, a configuration in which the width changes stepwise may be used.

  The present invention is not limited to the above-described embodiment, and various other configurations can be taken without departing from the gist of the present invention.

1A is a schematic configuration diagram (plan view) of a rotation angle detection sensor according to an embodiment of the present invention. FIG. 1B is a side view of the rotation angle detection sensor of FIG. 1A. It is a top view of the rotor of FIG. FIG. 3 is a plan view of the encoder structure of FIGS. 1 and 2. It is a schematic block diagram (enlarged plan view of the principal part) of the sensor main body of FIG. It is a figure which shows the opposing arrangement | positioning state of the coil and conductor pattern of FIG. It is a figure which shows embodiment which accommodated the phase member between the storage walls by A and B groove | channels. It is the top view which represented typically the arrangement | positioning of the storage wall and phase member of embodiment of FIG. It is sectional drawing of the rotor and encoder structure which show the form which accommodated the phase member between the storage walls by a processus | protrusion. It is a typical top view which shows the form of the shape of a phase member. It is a typical top view which shows the form of the shape of a phase member. It is a typical top view which shows the form of the shape of a phase member. It is a typical top view which shows the form of the shape of a phase member. It is a typical top view which shows the form of the shape of an A and B phase member. It is a typical top view which shows the form of the shape of an A and B phase member. It is a perspective view of the rotation angle detection sensor which provided the encoder structure which consists of a phase member in the outer peripheral surface of a rotor. It is a perspective view of the rotation angle detection sensor which provided the encoder structure which consists of a phase member in the internal peripheral surface of a rotor. FIG. 16 is a perspective view of a configuration in which the configuration of FIG. 15 is modified and a phase member is stored between storage walls formed by grooves. It is a figure which shows the phase member before A and B press work. It is a side view of the phase member of curve shape after press processing. It is a figure explaining the case where A and B plate-shaped members are punched and the encoder structure is formed.

Explanation of symbols

1 Rotating shaft, 2 Rotator, 3 Encoder structure, 4 Sensor body, 5 Phase member, 6 Groove, 7 Storage wall, 8 Protrusion, 9 Overlap, C1, C2, C3, C4 Coil

Claims (3)

A rotating body,
An encoder structure comprising a conductor pattern rotatably mounted with the rotating body, wherein a width dimension of the conductor pattern periodically changes;
A rotation angle detection sensor comprising a plurality of inductance elements, and a sensor body that is disposed opposite to a side where the encoder structure of the rotating body is formed and spaced from the sensor body,
The encoder structure uses a phase member that constitutes at least one period of a periodic change in the width dimension of the conductor pattern, and a plurality of the phase members having the same period and shape are annularly brought into contact with each other. Arranged on the rotating body ,
A rotation angle detection sensor , wherein a longitudinal dimension of an air core portion of the inductance element is formed larger than a maximum width dimension of the conductor pattern . The rotation angle detection sensor according to claim 1,
The rotating body is provided with a storage wall for storing the encoder structure,
The rotation angle detection sensor, wherein each phase member of the encoder structure is housed in a housing part between the housing walls. The rotation angle detection sensor according to claim 2,
Each of the phase members is in contact with the storage wall at least at three or more points.

Images