JP6673788B2 - Rotation angle detector - Google Patents

Description

  The present invention relates to a rotation angle detection device.

  As a conventional rotation angle detection device, for example, a device described in Patent Document 1 below is known.

  That is, the rotation angle detection device according to this patent document includes a magnet member that fits around the rotation shaft and rotates integrally with the rotation shaft, and a magnetic sensor that detects a magnetic field of the magnet member. The rotation angle of the rotating shaft is detected based on the detection output of.

JP 2003-32988 A

  However, in the conventional rotation angle detecting device, when assembling the magnet member to the rotating shaft, it is necessary to press the axial end face of the magnet member to fit the magnet member to the rotating shaft. Therefore, the pressing may damage the magnet member or adversely affect the magnetic field characteristics of the magnet member.

  The present invention has been devised in view of such a technical problem, and provides a rotation angle detection device capable of suppressing damage to a magnet member and adverse effects on magnetic field characteristics.

  According to one aspect of the present invention, there is provided a shaft member fixed to a rotating body, and a magnet member fixed to the shaft member, wherein the magnet member has one end of the shaft member on one axial side of the magnet member. It is fixed to the shaft member so that the portion is exposed.

  ADVANTAGE OF THE INVENTION According to this invention, damage to a magnet member and the bad influence on magnetic field characteristics can be suppressed.

1 is a cross-sectional view of a rotation angle detection device according to a first embodiment of the present invention. FIG. 2 is an enlarged sectional view around a magnet member shown in FIG. 1. 3A is a plan view of the magnet member shown in FIG. 2, and FIG. 3B is a cross-sectional view taken along line AA of FIG. It is sectional drawing of the magnet member which shows the 1st modification of 1st Embodiment of this invention. It is sectional drawing of the magnet member which shows the 2nd modification of 1st Embodiment of this invention. It is sectional drawing of the magnet member which shows 2nd Embodiment of this invention. It is sectional drawing of the magnet member which shows the modification of 2nd Embodiment of this invention. It is sectional drawing of the magnet member which shows 3rd Embodiment of this invention. It is an expanded sectional view around a magnet member showing a 4th embodiment of the present invention.

  Hereinafter, an embodiment of a rotation angle detection device according to the present invention will be described in detail with reference to the drawings.

[First Embodiment]
1 to 3 show a first embodiment of a rotation angle detecting device according to the present invention.

(Configuration of rotation angle detection device)
FIG. 1 is a longitudinal sectional view of the rotation angle detecting device 1 obtained by cutting the rotation angle detecting device 1 attached to the electric motor 2 along the rotation axis Z of the electric motor 2. In the description of the figure, a direction parallel to the rotation axis Z of the electric motor 2 is referred to as an “axial direction”, a direction orthogonal to the rotation axis Z of the electric motor 2 is referred to as a “radial direction”, and a direction around the rotation axis Z of the electric motor 2 is referred to. Is referred to as a “circumferential direction” and will be described.

  As shown in FIG. 1, the rotation angle detection device 1 is configured such that one side in the axial direction is connected to a driven member (not shown) and the other end in the axial direction of a motor output shaft 21 of the electric motor 2 as a rotating body that rotates about a rotation axis Z. Provided on the side. Specifically, the rotation angle detecting device 1 includes a shaft member 3 provided on the other axial side of the motor output shaft 21, a magnet member 4 provided on the shaft member 3, and an axial direction And a magnetic sensor 5 provided on one side.

  FIG. 2 is an enlarged view of a main part of FIG. 1 and shows an enlarged cross-sectional view around the magnet member 4. In the description of the figure, the direction parallel to the rotation axis Z of the motor output shaft 21 is the “axial direction”, the direction orthogonal to the rotation axis Z of the motor output shaft 21 is the “radial direction”, and the rotation of the motor output shaft 21 is The direction around the axis Z will be referred to as a “circumferential direction” for explanation.

  The motor output shaft 21 of the electric motor 2 is formed so as to open toward one side in the direction of the rotation axis Z, and has an opening 21 a as a fixed portion into which the shaft member 3 is press-fitted.

  The shaft member 3 is made of a non-magnetic material, for example, a stainless material, and has the same diameter over the entire area in the axial direction. The shaft member 3 has a detent engaging portion 31 that regulates relative rotation with respect to the magnet member 4 in an axial region that is in contact with the magnet member 4 on the outer periphery on one axial side. The detent engaging portion 31 is formed by a convex portion 31 a or a concave portion 31 b formed in a mesh shape by so-called knurling, and is axially extended from one axial end of the shaft member 3 by an axial region of a concave portion 43 described later. It is provided offset to the other side. In other words, at one end in the axial direction of the shaft member 3, an exposed portion 32 exposed from one end in the axial direction of the magnet member 4 is provided on one side in the axial direction beyond the detent engaging portion 31. Is provided.

  The detent engaging portion 31 is not limited to a mesh formed by the knurling process. For example, a spline shape as shown in FIG. 4, that is, a convex portion 31a extending in the axial direction may be used. Any configuration is possible as long as it is a structure that can prevent the rotation of the magnet member 4 with respect to the shaft member 3, such as a configuration in which the concave portions 31b are alternately formed in the circumferential direction.

  The shaft member 3 has a connection portion 33 formed at the other end in the axial direction, which is connected to the motor output shaft 21 by being pressed into the opening 21 a of the motor output shaft 21. The connection portion 33 has a slit portion 34 which is cut out on the other axial side of the motor output shaft 21 and extends in the rotation axis Z. That is, since the slit portion 34 is formed, the connecting portion 33 is easily bent and deformed, and the diameter of the connecting portion 33 is easily reduced, so that the connecting portion 33 can be easily press-fitted into the opening 21 a of the motor output shaft 21. ing.

  The magnet member 4 is made of a mixed material obtained by mixing a magnetic material such as neodymium and a resin material such as polyphenylene sulfide (PPS), and uses the holder member 6 as a cover member as a part of a molding die. Accordingly, the holder member 6 is formed on the inner peripheral side by injection molding. The magnet member 4 is magnetized by a predetermined magnetizing means, so that N poles and S poles are alternately arranged in the rotation direction of the motor output shaft 21. More specifically, the first N-pole magnetized portion N1 and the first S-pole magnetized portion S1, which are a pair of magnetized portions, and the second N-pole magnetized portion N2 and the second S-pole magnetized portion S2 are formed by the rotation axis Z. Are provided so as to be staggered.

  The magnetic sensor 5 is a well-known GMR element (magnetoresistive element), and is disposed so as to face the magnet member 4, and detects a change in the magnitude or direction of the magnetic field of the magnet member 4 accompanying rotation of the motor output shaft 21. By detecting, the rotation angle of the motor output shaft 21 is detected.

  3A and 3B show the magnet member 4. FIG. 3A is a plan view of the magnet member 4 shown in FIG. 2, and FIG. 3B is a cross-sectional view taken along line AA of FIG. In the description of the figure, the direction parallel to the center axis Z of the shaft member 3 is referred to as “axial direction”, the direction perpendicular to the center axis Z of the shaft member 3 is referred to as “radial direction”, and the direction around the center axis Z of the shaft member 3. Is referred to as a “circumferential direction” and will be described.

  The magnet member 4 has a main body portion 41 formed on the outer peripheral side, and a cylindrical adjacent region 42 which is a portion radially inside the main body portion 41 and adjacent to the shaft member 3. It is formed integrally. Further, the magnet member 4 is formed such that the main body portion 41 protrudes to one side in the axial direction from the adjacent region 42 by the axial region of the exposed portion 32 of the shaft member 3. As a result, a recess 43 is formed in the center of one end of the magnet member 4 on the one side in the axial direction. That is, by forming the concave portion 43, the exposed portion 32 of the shaft member 3 is projected and exposed to one side in the axial direction from the end surface 42 a on the one side in the axial direction of the adjacent region 42, and the exposed portion 32 of the main body 41 is The end surface 41a on the side and the end surface 32a on the one side in the axial direction of the shaft member 3 are configured to be on the same plane.

  The form in which the concave portion 43 of the magnet member 4 is formed is not limited to the form in which the axial end face 41a of the main body 41 and the axial end face 32a of the shaft member 3 are coplanar. 5, an end surface 41a on one side in the axial direction of the main body portion 41 may protrude to one side in the axial direction from an end surface 32a on one side in the axial direction of the shaft member 3.

  On the outer peripheral side of the magnet member 4, an axial locking portion that restricts the relative movement of the magnet member 4 in the axial direction with respect to the holder member 6 by being locked to an axial stopper portion 62 of the holder member 6 described below. 44 is formed integrally with the magnet member 4. The axial locking portion 44 is formed integrally with the first axial locking portion 44a formed integrally with the other axial end of the main body portion 41, and is formed integrally with the axial other end of the adjacent region 42. A second axial locking portion 44b.

  The first axial locking portion 44 a is formed to protrude radially outward of the main body 41 so as to have a slightly larger diameter than the general portion 41 b of the main body 41, and extends along the circumferential direction of the main body 41. It is formed continuously. The first axial locking portion 44a is locked to a first axial retaining portion 62a described later, whereby the relative movement in the axial direction with respect to the holder member 6 is restricted, and the first axial locking portion 44a is prevented from being removed from the holder member 6. You.

  The second axial locking portion 44b is formed to protrude radially outward of the adjacent region 42 so as to have a slightly larger diameter than the general portion 42b of the adjacent region 42, and is continuous along the circumferential direction of the adjacent region 42. Formed. The second axial direction locking portion 44b is locked to a second axial direction retaining portion 62b described later, so that relative movement in the axial direction with respect to the holder member 6 is restricted, and the second axial direction locking portion 44b is prevented from being removed from the holder member 6. You.

  Further, the outer peripheral side of one end of the magnet member 4 in the axial direction is engaged with a relative rotation restricting portion 63, 63 of the holder member 6, which will be described later, so as to regulate the relative rotation of the magnet member 4 with respect to the holder member 6. A pair of circumferential locking portions 45, 45 are formed integrally with the magnet member 4. The circumferential locking portions 45, 45 are provided at circumferential positions that are axially symmetric with respect to the center axis Z of the shaft member 3, and each have a concave shape that is recessed radially inward with respect to the general portion 41 b of the main body 41. Is formed. Specifically, the circumferential locking portions 45, 45 have a substantially triangular cross section corresponding to the relative rotation restricting portions 63, 63 described later. The relative movement in the circumferential direction with respect to the member 6 is restricted, and the rotation of the holder member 6 is stopped.

  The holder member 6 is made of a magnetic material, for example, a stainless steel material, and has a substantially cylindrical tubular portion 61 whose diameter decreases stepwise from a large-diameter portion 611 on one side in the axial direction to a small-diameter portion 612 on the other side. A magnet housing part 60 for housing the magnet member 4 is formed inside the cylindrical part 61. Further, on the inner peripheral side of the cylindrical portion 61, an axial stopper portion 62 for preventing the magnet member 4 from coming off is formed.

  The axial-direction retaining portion 62 has a first axial-direction retaining portion 62a formed at the other axial end of the large-diameter portion 611 and a first axial-forming end formed at the other axial end of the small-diameter portion 612. And a biaxial-direction retaining portion 62b. The first axial retaining portion 62a is formed so as to have a substantially arc-shaped cross section and extend in the circumferential direction. The second axial direction retaining portion 62b is formed in a conical taper shape such that the diameter gradually increases toward the other side in the axial direction.

A pair of relative rotation restricting portions 63, 63 for restricting relative rotation (rotation prevention) of the magnet member 4 are provided on the inner peripheral side of one axial end of the cylindrical portion 61 of the holder member 6. 6 are formed integrally. The relative rotation restricting portions 63, 63 are provided at circumferential positions that are axially symmetric with respect to the central axis Z of the shaft member 3, and protrude radially inward from the general portion 611a of the large diameter portion 611. It is formed so as to be convex and extend in the axial direction in a predetermined region in the axial direction.
More specifically, the relative rotation restricting portions 63, 63 are provided on one end in the axial direction of the cylindrical portion 61 (large-diameter portion 611) of the holder member 6 in which the magnet member 4 is filled on the inner peripheral side. It is formed so as to bite into the outer periphery (circumferential locking portions 45, 45) of the magnet member 4 by crushing and crimping inward from the side in the radial direction.

(Method of fixing magnet member 4)
The magnet member 4 formed integrally with the shaft member 3 presses the end surface 32a of the exposed portion 32 of the shaft member 3 with a predetermined jig (not shown), and the connection portion 33 of the shaft member 3 By being press-fitted into the opening 21a, it is fixed to the motor output shaft 21. That is, when the end surface 32 a of the exposed portion 32 is pressed, the connecting portion 33 of the shaft member 3 is reduced in diameter through the slit portion 34, and is guided by the opening portion 21 a of the motor output shaft 21. It is press-fitted and fixed in the portion 21a.

(Effect of rotation angle detection device)
As described above, in the conventional rotation angle detection device, a structure in which the magnet member 4 is directly fixed to the motor output shaft 21 has been adopted. For this reason, when fixing the magnet member 4 to the motor output shaft 21, it is necessary to directly press the axial end face of the magnet member 4 molded using a resin material as a binder and to fit the magnet member 4 to the motor output shaft 21. However, in this case, there is a possibility that the magnet member 4 may be damaged by the pressing force accompanying the pressing. If the pressing is performed after the magnetization, the magnetic field characteristics of the magnet member 4 may be adversely affected.

  On the other hand, the rotation angle detecting device 1 according to the present embodiment can solve the problem of the conventional rotation angle detecting device by providing the following effects.

  The rotation angle detection device 1 is a rotation angle detection device that detects a rotation angle of a rotating body, and includes a motor output shaft 21 that is a rotating body that rotates about a rotation axis Z, and a rotation axis Z of the motor output shaft 21. And a magnet member provided on the shaft member 3, which is formed of a mixed material of a magnetic material and a resin material, and is formed in a direction around the rotation axis Z. An N-pole and an S-pole are arranged, and a magnet member 4 provided such that one end of the shaft member 3 in the direction of the rotation axis Z is exposed on one side of the magnet member 4 in the direction of the rotation axis Z; Magnetic sensor provided on one side in the direction of the rotation axis Z to detect the rotation angle of the motor output shaft 21 by detecting a change in the magnitude or direction of the magnetic field of the magnet member 4 accompanying rotation of the motor output shaft 21. 5 It has a.

  As described above, in the present embodiment, the magnet member 4 is fixed to the motor output shaft 21 via the shaft member 3, and one end in the axial direction of the shaft member 3 serves as the exposed portion 32 in the axial direction of the magnet member 4. It is exposed on one side. Thus, the magnet member 4 can be fixed to the motor output shaft 21 by pressing the end face of the exposed portion 32, and it is not necessary to directly apply a pressing force to the magnet member 4. As a result, damage to the magnet member 4 and adverse effects on magnetic field characteristics can be suppressed.

  Moreover, the magnet member 4 includes a main body portion 41 and an adjacent region 42 that is a portion that is radially inner than the main body portion 41 and adjacent to the shaft member 3 in the radial direction orthogonal to the rotation axis Z, In the shaft member 3, the exposed portion 32, which is one end of the shaft member 3, protrudes beyond the adjacent region 42 of the magnet member 4 in the rotation axis Z direction.

  As described above, since the exposed portion 32 of the shaft member 3 protrudes from the adjacent region 42 of the magnet member 4, the pressing jig (not shown) when the magnet member 4 is fixed to the motor output shaft 21 is used. Contact of the fastening tool described later with the magnet member 4 is suppressed, and the adverse effect on the magnet member 4 during the pressing and fixing can be further suppressed.

  Further, in the magnet member 4, the main body portion 41 protrudes from the adjacent region 42 to one side in the rotation axis Z direction.

  As described above, in the magnet member 4, the main body 41 protrudes to one side in the axial direction from the adjacent area 42, so that the main body 41 and the magnetic sensor 5 can be closer to each other, and the magnetic sensor 5 Can improve the magnetic field detection accuracy.

  In addition, the magnet member 4 has an end surface 41a on one side in the rotation axis Z direction of the main body portion 41 on the same plane as an end surface 32a of the exposed portion 32 that is one end surface in the rotation axis Z direction of the shaft member 3, or It protrudes to one side in the rotation axis Z direction.

  As described above, the end surface 41a on one side in the axial direction of the main body portion 41 projects on the same plane as 32a of the exposed portion 32 of the shaft member 3, or protrudes to one side in the axial direction from the end surface 32a of the exposed portion 32 of the shaft member 3. Accordingly, when the magnet member 4 is magnetized, there is an advantage that interference between the magnetizing device (not shown) and the shaft member 3 can be suppressed.

  Further, the shaft member 3 has a detent engaging portion 31 that is provided on an outer peripheral side of the shaft member 3 and that is in contact with the magnet member 4 and that regulates relative rotation with respect to the magnet member 4.

  As described above, since the rotation preventing engagement portion 31 that regulates the relative rotation with respect to the magnet member 4 is provided on the outer peripheral side of the shaft member 3, the relative rotation between the shaft member 3 and the magnet member 4 is suppressed. Is possible, and the detection accuracy of the rotation angle by the magnetic sensor 5 can be improved.

  Further, the detent engaging portion 31 is a convex portion 31a or a concave portion 31b formed in a mesh shape.

  As described above, by using the mesh-shaped convex portion 31a or concave portion 31b as the detent engaging portion 31, the effect of suppressing both the rotational direction and the axial direction of the magnet member 4 with respect to the shaft member 3 can be reduced. Can play.

  The shaft member 3 is formed of a non-magnetic material.

  That is, when the shaft member 3 is made of a magnetic material, the shaft member 3 may be magnetized and affect the magnetic field of the magnet member 4, but the shaft member 3 is made of a non-magnetic material. Thereby, there is an advantage that the influence of the magnet member 4 on the magnetic field can be suppressed.

  The magnet member 4 is provided with a holder member 6 formed of a magnetic material and serving as a cover member that covers the magnet member 4 on a radially outer side perpendicular to the rotation axis Z.

  As described above, since the holder member 6 made of a magnetic material is provided on the outer peripheral side of the magnet member 4, the influence of an external magnetic field can be reduced by the holder member 6.

  Furthermore, the holder member 6 includes a cylindrical portion 61 formed so as to surround the shaft member 3, and is a concave portion provided on the inner peripheral side of the cylindrical portion 61 and extending in a direction around the rotation axis Z. It has a direction retaining portion 62.

  As described above, by providing the axial direction retaining portion 62 on the inner peripheral side of the cylindrical portion 61 of the holder member 6, the axial direction retaining portion 62 enters the magnet member 4, and An axial relative displacement with respect to the holder member 6 can be suppressed.

  In addition, the holder member 6 includes a cylindrical portion 61 formed so as to surround the shaft member 3 and is a convex portion provided on the inner peripheral side of the cylindrical portion 61 and extending in the direction of the rotation axis Z. It has a relative rotation restricting portion 63.

  As described above, since the relative rotation restricting portion 63 is provided on the inner peripheral side of the cylindrical portion 61 of the holder member 6, the relative rotation restricting portion 63 enters the magnet member 4, and the magnet member 4 and the holder member 6 can be suppressed from rotating in the circumferential direction.

  The motor output shaft 21 has an opening 21a that opens toward one side in the direction of the rotation axis Z, and has an opening 21a into which the shaft member 3 is press-fitted. The shaft member 3 is provided at the other end in the direction of the rotation axis Z. And a slit 34 extending in the direction of the rotation axis Z.

  As described above, the axially extending slit portion 34 is provided at the other end of the shaft member 3 in the axial direction, so that the shaft member 3 which is a portion to be pressed into the motor output shaft 21 has the other axial direction. As a result, the end of the side can be easily reduced in diameter, so that there is an advantage that the press-fitting operation of the magnet member 4 can be easily performed. Further, the slit 34 can absorb a relative change in the radial dimension between the opening 21a and the shaft member 3 due to the difference in the linear expansion coefficient between the motor output shaft 21 and the shaft member 3.

[Second embodiment]
FIG. 6 shows a second embodiment of the rotation angle detecting device according to the present invention. In this embodiment, since the basic configuration of the rotation angle detecting device 1 is the same as that of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals. A detailed description is omitted (the same applies to each embodiment below).

  As shown in FIG. 6, in the present embodiment, in the magnet member 4, the concave portion 43 according to the first embodiment is eliminated, and the axial end surface 41 a of the main body 41 and the axial one side of the adjacent region 42 are provided. Is formed on the same plane as the end surface 42a. In other words, the end surface 32a of the exposed portion 32 of the shaft member 3 is configured to protrude to one side in the axial direction from the end surfaces 41a and 42a of the main body portion 41 and the adjacent region 42 on one side in the axial direction.

  As described above, in the present embodiment, the entire end face on one side in the axial direction of the magnet member 4 is offset toward the other side in the axial direction with respect to the end face 32a on one side in the axial direction of the exposed portion 32 of the shaft member 3. Thereby, when the magnet member 4 is fixed to the motor output shaft 21, contact of the pressing jig (not shown) or a fastening tool described later with the magnet member 4 can be more effectively suppressed.

  Further, in the present embodiment, since the detection of the magnetic field by the magnetic sensor 5 is mainly performed by the main body portion 41, when the magnet member 4 is injection-molded, as shown in FIG. It is desirable to dispose a gate of a molding die (not shown) so that is formed.

  That is, the magnet member 4 is formed by molding, and has the gate marks 46, 46 of the gate provided in the adjacent region 42 and filling the mold with the molten resin material.

  By arranging the gate positions so that the gate marks 46 are formed in the adjacent region 42, there is an advantage that the influence of the gate marks 46 on the detection accuracy of the magnetic field can be suppressed.

[Third embodiment]
FIG. 8 shows a third embodiment of the rotation angle detecting device according to the present invention.

  As shown in FIG. 8, in the present embodiment, the magnet accommodating portion 60 in the small diameter portion 612 of the holder member 6 is eliminated, and the holder member 6 is directly press-fitted and fixed to the shaft member 3 via the small diameter portion 612.

  Thus, in the present embodiment, the holder member 6 is fixed to the shaft member 3. That is, since the holder member 6 having higher strength than the magnet member 4 is directly fixed to the shaft member 3, the holding force of the magnet member 4 is improved as compared with the case where the holder member 6 is fixed to the shaft member 3 using only the magnet member 4. be able to.

[Fourth embodiment]
FIG. 9 shows a fourth embodiment of the rotation angle detecting device according to the present invention.

  As shown in FIG. 9, in the present embodiment, the slit portion 34 according to the first embodiment is omitted, and a male screw portion 35 is formed on the outer peripheral side of the other end in the axial direction of the shaft member 3. On the inner peripheral side of the opening 21 a of the motor output shaft 21, a female screw portion 22 screwed to the male screw portion 35 is formed. That is, the shaft member 3 is fastened and fixed to the motor output shaft 21 by screwing the male screw portion 35 of the shaft member 3 into the female screw portion 22 of the motor output shaft 21 instead of press fitting as in the first embodiment. .

  A concave tool engaging groove 36 for engaging a fastening tool (not shown) such as a driver or a wrench when fastening the shaft member 3 to the motor output shaft 21 is provided at one axial end of the shaft member 3. Are notched. In other words, the shaft member 3 can be fastened to the motor output shaft 21 by rotating the fastening tool (not shown) by engaging it with the tool engagement groove 36.

  From the above, in the present embodiment, by fixing the shaft member 3 to the motor output shaft 21, the shaft member 3 can be fixed more firmly and easily than the press-fitting fixing according to the first embodiment. There are benefits.

  The present invention is not limited to the configuration of the above-described embodiment, and can be freely changed in accordance with the specifications of the electric motor to be applied as long as the function and effect of the present invention can be exhibited.

  In particular, the means for fixing the shaft member 3 to the motor output shaft 21 is not limited to the press-fitting or fastening disclosed in the above embodiment, but may be any method as long as it can be fixed using the exposed portion 32. Good.

  Further, in the rotation angle detecting device 1, the holder member 6 is not an essential component, and thus can be deleted according to the specification or the like.

  As the rotation angle detection device based on the embodiment described above, for example, the following configuration can be considered.

  That is, in one aspect, the rotation angle detection device is a rotation angle detection device that detects a rotation angle of a rotation body, and includes a rotation body that rotates about a rotation axis, and a rotation axis of the rotation body. A shaft member fixed to a fixing portion provided on one side, and a magnet member provided on the shaft member, the magnet member being formed of a mixed material of a magnetic material and a resin material, and having an N pole in a direction around the rotation axis. A magnet member provided so that one end in the rotation axis direction of the shaft member is exposed on one side of the rotation axis direction of the magnet member, and the S pole is more than the magnet member. A magnetic cell provided on one side in the direction of the rotation axis for detecting a rotation angle of the rotating body by detecting a change in the magnitude or direction of a magnetic field of the magnet member accompanying rotation of the rotating body. With support and, the.

  In a preferred aspect of the rotation angle detecting device, the magnet member is adjacent to the main body portion in a radial direction orthogonal to the rotation axis and radially inside the main body portion and adjacent to the shaft member. And the shaft member, wherein one end of the shaft member protrudes in the direction of the rotation axis from the adjacent region of the magnet member.

  In another preferred aspect, in any one of the aspects of the rotation angle detecting device, in the magnet member, the main body part projects to one side in the rotation axis direction from the adjacent area.

  In still another preferred aspect, in any one of the aspects of the rotation angle detection device, the magnet member may be configured such that one end face of the main body in the rotation axis direction is one side of the shaft member in the rotation axis direction. It protrudes on the same plane as the end portion or on one side in the rotation axis direction.

  In still another preferred aspect, in any one of the aspects of the rotation angle detecting device, the magnet member is formed by molding, and is filled in a mold with a molten resin material provided in the adjacent region. The gate has a gate mark.

  In still another preferred aspect, in any one of the aspects of the rotation angle detection device, the shaft member is provided on an outer peripheral side of the shaft member and is provided in a region in contact with the magnet member. It has a detent engagement portion that regulates relative rotation.

  In still another preferred aspect, in any one of the aspects of the rotation angle detecting device, the detent engaging portion is a convex portion or a concave portion formed in a mesh shape.

  In still another preferred aspect, in any one of the aspects of the rotation angle detecting device, the shaft member is formed of a non-magnetic material.

  In still another preferred aspect, in any one of the aspects of the rotation angle detecting device, the magnet member is provided with a cover member formed of a magnetic material and covering the magnet member on a radially outer side perpendicular to the rotation axis. .

  In still another preferred aspect, in any one of the aspects of the rotation angle detecting device, the cover member includes a tubular portion formed so as to surround the shaft member, and an inner peripheral side of the tubular portion. And an axial retaining portion which is a concave portion extending in a direction around the rotation axis.

  In still another preferred aspect, in any one of the aspects of the rotation angle detecting device, the cover member includes a tubular portion formed so as to surround the shaft member, and an inner peripheral side of the tubular portion. And a relative rotation restricting portion that is a convex portion extending in the direction of the rotation axis.

  In still another preferred aspect, in any of the aspects of the rotation angle detecting device, the cover member is fixed to the shaft member.

  In still another preferred aspect, in any one of the aspects of the rotation angle detection device, the rotating body has an opening that opens toward one side in the rotation axis direction and the shaft member is press-fitted, The shaft member has a slit provided at the other end in the rotation axis direction and extending in the rotation axis direction.

DESCRIPTION OF SYMBOLS 1 ... Rotation angle detection apparatus, 21 ... Motor output shaft (rotary body), 3 ... Shaft member, 4 ... Magnet member, N1, N2 ... 1st, 2nd N pole magnetized part (N pole), S1, S2 ... No. 1, second S-pole magnetized portion (S-pole) 5: magnetic sensor, Z: rotation axis

Claims (11)

A rotation angle detection device that detects a rotation angle of a rotating body,
A rotating body that rotates about a rotation axis,
A shaft member formed of a non-magnetic material and fastened and fixed to the rotating body,
A magnet member provided on the shaft member, including a cover member made of a magnetic material that covers the magnet member on a radially outer side perpendicular to the rotation axis, wherein the cover member is made of a mixed material of a magnetic material and a resin material. The magnet member is formed integrally, and N pole and S pole are arranged in a direction around the rotation axis, and one side of the magnet member in the rotation axis direction has the rotation axis direction of the shaft member. A magnet member provided so that one end of the magnet is exposed,
A magnet provided on one side of the rotation axis direction with respect to the magnet member, for detecting a rotation angle of the rotating body by detecting a change in the magnitude or direction of a magnetic field of the magnet member accompanying rotation of the rotating body; Sensors and
A rotation angle detecting device comprising: The rotation angle detection device according to claim 1,
The magnet member includes a main body portion and an adjacent region that is a portion that is radially inner than the main body portion in the radial direction orthogonal to the rotation axis and is adjacent to the shaft member,
The rotation angle detecting device, wherein the shaft member has one end portion of the shaft member protruding in the rotation axis direction from the adjacent region of the magnet member. The rotation angle detection device according to claim 2,
The rotation angle detection device according to claim 1, wherein the magnet member has the main body portion protruding to one side in the rotation axis direction from the adjacent region. The rotation angle detection device according to claim 3,
In the magnet member, an end surface on one side in the rotation axis direction of the main body portion projects on the same plane as an end surface on the one side in the rotation axis direction of the shaft member, or protrudes to one side in the rotation axis direction. A rotation angle detection device characterized by the above-mentioned. The rotation angle detection device according to claim 3,
The magnet member is pre-Symbol rotation angle detecting apparatus characterized by having a Gate trace to the adjacent region. The rotation angle detection device according to claim 1,
The rotation angle, wherein the shaft member has a detent engagement portion provided on an outer peripheral side of the shaft member and in contact with the magnet member to regulate relative rotation with the magnet member. Detection device. The rotation angle detection device according to claim 6,
The rotation angle detecting device, wherein the detent engaging portion is a convex portion or a concave portion formed in a mesh shape. The rotation angle detection device according to claim 1 ,
The cover member,
With a cylindrical portion formed to surround the shaft member,
A rotation angle detecting device, comprising: an axial stopper portion provided on an inner peripheral side of the cylindrical portion and extending in a direction around the rotation axis. The rotation angle detection device according to claim 1 ,
The cover member,
With a cylindrical portion formed to surround the shaft member,
A rotation angle detection device, comprising: a relative rotation restricting portion provided on an inner peripheral side of the cylindrical portion and extending in a direction of the rotation axis. The rotation angle detection device according to claim 1 ,
The rotation angle detecting device, wherein the cover member is fixed to the shaft member. The rotation angle detection device according to claim 1,
The rotating body has an opening that opens toward one side in the rotation axis direction, and the shaft member is press-fitted,
The rotation angle detecting device, wherein the shaft member has a slit provided at the other end in the rotation axis direction and extending in the rotation axis direction.

Images