JP2009133715A - Mounting structure of rotation angle sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate attachment and detachment by mounting a holder holding a permanent magnet without any backlash on a rotating shaft. <P>SOLUTION: A mounting structure of a rotation angle sensor cuts the edge of the rotating shaft 10 to be made a cross section D-shape, and sandwiches the cutout 11 and a shaft center to form a groove 12 orthogonal to the shaft center at a position separated from the edge being in a reverse side. The holder 20 is columnar, the permanent magnet 30 is mounted on the one end face 20a, a rotating shaft insertion hole 22 is formed from the other end face 20b in the center, and a retaining spring insertion hole 23 is formed from a circumferential face 20c so as to be intersected with the rotating shaft insertion hole 22. The bottom of the rotating shaft insertion hole 22 is formed to be matched with the edge of the rotating shaft 10. The holder 20 is pushed on the edge of the rotating shaft 10 and mounted to be retained and fixed by engaging the retaining spring 40 inserted from the retaining spring insertion hole 23 with the groove 12 of the rotating shaft 10 inserted in the rotating shaft insertion hole 22, and it can be detached by releasing the engagement. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a structure for mounting a rotation angle sensor for detecting a rotation angle of a rotation shaft to the rotation shaft.

  A permanent magnet is attached to the rotating shaft, the permanent magnet is rotationally displaced together with the rotating shaft, and the rotation angle of the rotating shaft is detected by detecting a change in the magnetic field accompanying the rotation with a magnetic sensor arranged on the fixed side with respect to the rotating shaft. A non-contact rotation angle sensor for detecting is conventionally known.

Patent Document 1 describes such a rotation angle sensor. In Patent Document 1, a permanent magnet is attached and fixed to one end of a rotating shaft with an adhesive.
JP-A-5-203402

  However, in such a method using an adhesive such as directly fixing and fixing a permanent magnet to the rotating shaft or bonding and fixing a holder or the like holding the permanent magnet to the rotating shaft, it is once removed after being attached. Is not easy, and there arises a problem that it cannot be removed, for example, when it is desired to remove it for maintenance.

  On the other hand, as a method of attaching a component to the rotating shaft so as to rotate together with the rotating shaft, for example, a method of press-fitting the rotating shaft into a hole provided in the component or a method of attaching the tip of the rotating shaft through a through hole provided in the component. There is a method of caulking, and further, a method of inserting the rotation shaft into the hole provided in the component and pressing the rotation shaft in the radial direction with a screw from the side of the component and fixing it, and inserting a pin from the side of the component There is a method of fixing the rotating shaft.

  However, as with the case of using an adhesive, press fitting and caulking are not easy to remove once attached, and if there is not enough space on the side of the part in the method using screws and pins, the screw can be turned, There is a problem that the work of removing the pins cannot be performed.

  In view of such a situation, the object of the present invention is to attach the holder holding the permanent magnet constituting the movable side (rotation part) of the rotation angle sensor firmly to the rotation shaft without looseness, and to be easily attached and detached. It is to provide a mounting structure.

  According to the first aspect of the present invention, the holder holding the permanent magnet is attached to the rotating shaft, and the change of the magnetic field accompanying the rotation of the permanent magnet is detected by the magnetic sensor arranged on the fixed side with respect to the rotating shaft. In the mounting structure of the rotation angle sensor for detecting the rotation angle to the rotation shaft, the tip of the rotation shaft is cut out to have a D-shaped cross section, and the tip is opposite to the notch on the opposite side of the notch and the shaft center. A groove is formed at a position perpendicular to the shaft center at a position away from the holder, the holder is cylindrical, a permanent magnet is attached to one end face thereof, and a rotary shaft insertion hole is formed in the center from the other end face. A retaining spring insertion hole is formed from the peripheral surface so as to intersect the insertion hole, and the bottom of the rotating shaft insertion hole is shaped to match the tip of the rotating shaft, and the retaining spring inserted from the retaining spring insertion hole Spring is inserted into the rotation axis By engaging with the groove of the rotating shaft inserted into the hole, the holder is pressed against the tip of the rotating shaft, and is fixed to the rotating shaft so that the holder is attached. By releasing, the holder can be removed from the rotating shaft.

  According to a second aspect of the present invention, in the first aspect of the present invention, the retaining spring comprises a pair of L-shaped leg portions and a connecting portion that connects one end side of the leg portions. The surface has an opening extending in the circumferential direction, and is formed so as to be inclined away from the one end surface.A pair of recesses are formed in the peripheral surface on the one end surface side from the opening, and the retaining spring is Inserted into the retaining spring insertion hole from the connecting portion side, each other end of the pair of leg portions is positioned in the recess, and the connecting portion is positioned in the groove and surrounded by the connecting portion and the pair of leg portions When the rotation shaft is positioned in the region, and the retaining spring is inserted into the retaining spring insertion hole, the elastic restoring force of the pair of leg portions whose L-shapes are pushed and widened draws the groove and the pair of recesses. It is set as the structure which acts.

  According to a third aspect of the present invention, in the second aspect of the present invention, when the retaining spring is pushed into the retaining spring insertion hole, the connecting portion moves out of the outer periphery of the rotating shaft and the engagement is released. The

  According to the present invention, it is possible to realize a mounting structure in which a holder that holds a permanent magnet that is a movable side of a rotation angle sensor can be firmly attached to a rotating shaft without looseness and can be easily attached and detached. it can.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows the appearance of an embodiment of a mounting structure of a rotation angle sensor according to the present invention. In the figure, 10 indicates a rotating shaft, 20 indicates a holder, 30 indicates a permanent magnet, and 40 indicates a retaining spring. Show. Reference numeral 50 denotes a magnetic sensor. In this example, the holder 20 holding the permanent magnet 30 is structured to be attached to the rotary shaft 10, and a retaining spring 40 is used for this attachment. In addition, illustration of the attachment and support structure of the magnetic sensor 50 arrange | positioned at the fixed side with respect to the rotating shaft 10 is abbreviate | omitted in FIG.

  2 and 3 show a CC cross section and a DD cross section in FIG. 1B, respectively, and FIG. 4 is an exploded view of each part. FIG. 5 shows the shape of the rotating shaft 10. First, the configuration of each part will be described.

  As shown in FIG. 5, a notch 11 is formed at the tip of the rotating shaft 10 to which the rotation angle sensor is attached, and the rotating shaft 10 in the portion where the notch 11 is formed has a D-shaped cross section. . Further, a groove 12 is formed in the rotary shaft 10 at a right angle to the axis. The groove 12 is on the opposite side of the notch 11 with respect to the axis, and is formed at a position farther from the tip than the notch 11 and is parallel to the bottom surface 12 a of the groove 12 and the axis that forms the notch 11. 11a is parallel.

  As shown in FIG. 2, a circular recess 21 is formed on one end surface 20a of the holder 20, and a disk-shaped permanent magnet 30 is bonded and fixed to the circular recess 21. ing. The permanent magnet 30 is magnetized in the radial direction.

  A rotation shaft insertion hole 22 is formed in the center of the holder 20 from the other end surface 20b, and a step portion 22a is formed in the bottom of the rotation shaft insertion hole 22, and the tip of the rotation shaft 10 in which the notch 11 is formed. Matched shape.

  Furthermore, in this example, a retaining spring insertion hole 23 and a pair of recesses 24 are formed in the holder 20.

  The retaining spring insertion hole 23 is formed from the peripheral surface 20 c so as to intersect the rotation shaft insertion hole 22, has an elongated opening 23 a extending in the circumferential direction on the peripheral surface 20 c, and is away from one end surface 20 a of the holder 20. It is formed to be inclined. The width of the retaining spring insertion hole 23 is larger than the diameter of the rotation shaft insertion hole 22, and the inner end thereof is located outside the rotation shaft insertion hole 22, that is, at a crossing point. The opening 23a is formed on the side where the step 22a of the rotary shaft insertion hole 22 is located.

  The pair of recesses 24 are formed on the circumferential surface 20c closer to the end surface 20a than the opening 23a of the retaining spring insertion hole 23 and arranged in the circumferential direction as shown in FIG. These recesses 24 are elongated in the direction of the center axis of the holder 20, and the cross-sectional shape cut along a plane parallel to the plane including the center axis of the holder 20 and the center line of the opening 23a of the retaining spring insertion hole 23 is shown in FIG. As shown, it is assumed to form a triangle (wedge shape). Of the two surfaces 24a and 24b of the concave portion 24 constituting the triangular cross section, the surface 24a located on the retaining spring insertion hole 23 side and the inner surface 23b intersecting the rotation shaft insertion hole 22 of the retaining spring insertion hole 23 are: In this example, it is configured to form approximately 90 degrees. The holder 20 is made of resin, for example.

  The retaining spring 40 is formed by bending a spring wire, and includes a pair of leg portions 41 having an L shape and a connecting portion 42 for connecting one end side of the leg portions 41 as shown in FIG. It is said. A pressure contact portion 41 a having an arc shape is formed at each other end of the pair of leg portions 41.

  Next, attachment to the rotating shaft 10 of the holder 20 to which the permanent magnet 30 is attached will be described.

  The retaining spring 40 is inserted into the retaining spring insertion hole 23 of the holder 20 from the connecting portion 42 side. The press contact portions 41 a formed on the pair of leg portions 41 are respectively accommodated and positioned in the concave portions 24 of the holder 20. The pair of leg portions 41 inserted into the retaining spring insertion hole 23 are located at both ends in the width direction (longitudinal direction of the opening 23a) of the retaining spring insertion hole 23, and the connecting portion 42 presses the retaining spring 40, By being pushed in, it is located at the inner end of the retaining spring insertion hole 23, and in this pressed state, the retaining spring 40 (connecting portion 42) is not positioned in the rotating shaft insertion hole 22.

  In this state, the rotary shaft 10 is inserted into the rotary shaft insertion hole 22 so that the position of the notch 11 coincides with the position of the step portion 22 a of the rotary shaft insertion hole 22. And after insertion, the press with respect to the retaining spring 40 is released. By releasing the pressing, the connecting portion 42 of the retaining spring 40 enters and engages with the groove 12 of the rotating shaft 10, and the rotating shaft 10 is prevented from being detached by the connecting portion 42 and is connected to the groove 12. And a pair of leg portions 41.

  The pair of leg portions 41 of the retaining spring 40 is inserted into the retaining spring insertion hole 23 and its L-shape is slightly expanded. While the holder 20 is pressed, the notch 11 of the rotating shaft 10 and the step portion 22a of the rotating shaft insertion hole 22 are engaged to fix the holder 20 to the rotating shaft 10.

FIG. 6 shows the force acting in this attached state, and the elastic restoring force of the retaining spring 40 is supported by the fulcrum P ₀ indicated by ○ and P ₁ marked with ○. It acts so as to draw the portion P ₂ , that is, the groove 12 of the rotating shaft 10 and the pair of recesses 24 of the holder 20. In the figure, the arrow indicates the direction of force.

  FIG. 7 shows a state in which the holder 20 can be attached / detached (attached / detached) to / from the rotary shaft 10. When removing the holder 20, the retaining spring 40 is pressed as shown by an arrow in the drawing to remove the holder 20. By pushing into the stop spring insertion hole 23, the connecting portion 42 is removed from the groove 12, and the connecting portion 42 is moved out of the outer periphery of the rotating shaft 10. Thereby, the holder 20 can be easily removed from the rotating shaft 10. At the time of attachment, as described above, the attachment can be made by simply pushing the retaining spring 40.

  As described above, according to this example, the holder 20 holding the permanent magnet 30 can be securely attached to the rotary shaft 10 without looseness, and the attachment / detachment can be simply performed by pushing the retaining spring 40. Can do.

The angle formed between the line connecting P ₁ and P ₂ in FIG. 6 and the axial direction of the rotating shaft 10 is about 20 to 70 degrees in order to obtain the pressing force of the holder 20 against the rotating shaft 10. It may be set within the range.

A is a perspective view showing an embodiment of a mounting structure of a rotation angle sensor according to the present invention, and B is a plan view thereof. CC sectional drawing of FIG. 1B. DD sectional drawing of FIG. 1B. The exploded perspective view of FIG. A is a side view of the rotating shaft in FIG. 1, and B is a bottom view thereof. The figure for demonstrating the action direction of the force in the attachment state of a holder. The figure for demonstrating the detachable state of a holder.

Claims (3)

A rotation angle sensor for detecting a rotation angle of the rotation shaft by attaching a holder holding a permanent magnet to the rotation shaft, and detecting a change in the magnetic field accompanying the rotation of the permanent magnet with a magnetic sensor arranged on a fixed side with respect to the rotation shaft. The mounting structure to the rotating shaft of
Cut the tip of the rotating shaft into a D-shaped cross section, and form a groove perpendicular to the shaft center at a position on the opposite side of the notch and the shaft center and away from the tip.
The holder has a cylindrical shape, the permanent magnet is attached to one end surface thereof, a rotation shaft insertion hole is formed in the center from the other end surface, and a retaining spring from the circumferential surface so as to intersect the rotation shaft insertion hole An insertion hole is formed,
The bottom of the rotary shaft insertion hole is shaped to match the tip of the rotary shaft,
The retaining spring inserted from the retaining spring insertion hole engages with the groove of the rotating shaft inserted into the rotating shaft insertion hole, whereby the holder is pressed against the tip of the rotating shaft, and It is structured to be fixed to the rotating shaft and fixed to the holder.
An attachment structure for a rotation angle sensor, wherein the holder can be removed from the rotation shaft by releasing the engagement. In the rotation angle sensor mounting structure according to claim 1,
The retaining spring comprises a pair of L-shaped leg portions and a connecting portion that connects one end side of the leg portions,
The retaining spring insertion hole has an opening extending in the circumferential direction on the peripheral surface, and is formed so as to be inclined away from the one end surface.
A pair of recesses are formed on the peripheral surface on the one end surface side from the opening,
The retaining spring is inserted into the retaining spring insertion hole from the connecting portion side, and the other ends of the pair of legs are respectively positioned in the recesses,
The rotating shaft is positioned in a region surrounded by the connecting portion and the pair of leg portions, the connecting portion being positioned in the groove;
When the retaining spring is inserted into the retaining spring insertion hole, the elastic restoring force of the pair of leg portions whose L-shape is pushed and widened acts so as to draw the groove and the pair of concave portions together. A structure for mounting a rotation angle sensor. In the mounting structure of the rotation angle sensor according to claim 2,
The rotation angle is characterized in that the engagement portion is released by pushing the retaining spring into the retaining spring insertion hole so that the connecting portion moves outward from the outer periphery of the rotating shaft. Sensor mounting structure.

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