JP4776574B2 - Rotation sensor - Google Patents

Description

  The present invention is a rotation sensor suitable for a rotation sensor that is mounted between a combination switch bracket of a steering column of a vehicle, for example, and a steering shaft, and detects a rotation direction and a rotation angle of the steering shaft. About.

A rotation sensor for detecting a rotation direction and a rotation angle of the steering shaft is provided between a pair of relatively rotating members, for example, a combination switch bracket (vehicle body side) of a steering column of a vehicle and a steering shaft and a steering wheel (rotation side). It is attached (for example, refer to Patent Document 1) .

As an example of such a rotation sensor, for example, as shown in FIGS. 6 and 7, a stator 1 that constitutes a part of a case fixed to the vehicle body side and is provided with a through hole 1 a through which a steering shaft (not shown) is passed. A cylindrical portion 2a that is disposed on one side (lower side) of the through-hole 1a, is inserted through the steering shaft so as to be rotatable integrally with the steering shaft, and an end portion of the cylindrical portion 2a includes the through-hole 1a. The rotor 2 having a flange 2b facing the peripheral edge and having a diameter larger than the through hole 1a, and the other side (upper side) of the through hole 1a of the stator 1 are fitted into the inside of the cylindrical part 2a of the rotor 2 and the steering shaft is inserted. A cylindrical portion 3a, and a flange 3b opposite to the peripheral edge of the through hole 1a at the end of the cylindrical portion 3a and having a diameter larger than that of the through hole 1a. b, a sleeve 3 for rotatably holding the rotor 2 on the stator 1 with a predetermined clearance, and a fixing means 4 provided on the cylindrical portion 2a of the rotor 2 and the cylindrical portion 3a of the sleeve 3 for fixing them. The structure provided with is known.

  The fixing means 4 includes a vertically long fitting window 6 formed in the axial direction from the tongue-shaped extending portion 5 extending in the axial direction to the lower end of the cylindrical portion 3a of the sleeve 3, and the upper end surface of the flange 3b. The inner surface of the rotor 2 is tapered at a predetermined position from the upper end 7a toward the lower end 7b so as to be substantially wedge-shaped when viewed from the side protruding inward, and can be fitted to the fitting window 6 from the upper end 7a side. The fitting projection 7 is formed on both sides of the fitting projection 7 of the cylindrical portion 2a along the axial direction, and the guide portion 8 guides the extending portion 5 in the axial direction. Such fixing means 4 are formed in a plurality of places, for example, three places at predetermined intervals along the circumferential direction in the cylindrical portion 2 a of the rotor 2 and the cylindrical portion 3 a of the sleeve 3.

  Then, as shown in FIGS. 7 and 8, the cylindrical portion 3 a and the extending portion 5 of the sleeve 3 are inserted into the cylindrical portion 2 a of the rotor 2 along the guide portion 8 through the through hole 1 a of the stator 1. The rotor 2 and the sleeve 3 are fixed by fitting the fitting protrusion 7 to the above. In this state, as shown in FIG. 9, the flange 2 b of the rotor 2 and the flange 3 b of the sleeve 3 sandwich the opposing peripheral edge of the through hole 1 a of the stator 1 with a slight clearance d, and these rotor 2 and sleeve 3. Can be smoothly rotated with respect to the stator 1 together with the steering shaft.

  In FIG. 7, the clearance d is depicted as a gap between the upper surface of the peripheral edge of the through hole 1a of the stator 1 and the lower surface of the flange 3b of the sleeve 3, but the upper surface of the flange 2a of the rotor 2 and the through hole 1a. It is good also as a clearance between the lower surfaces of a peripheral part. Or it is good also as clearance between the flange 2b of both sides, the flange 3b, and the peripheral part both surfaces which the through-hole 1a opposes. In this case, the sum of the clearances on both sides of the through hole 1a becomes a predetermined clearance d.

A slit plate that is inserted into the steering shaft so as not to rotate relative to the steering shaft; and a pair of body cases that are divided into two by a plane orthogonal to the central axis of the steering shaft and that rotatably accommodate the slit plate, The outer peripheral wall of the case is formed to be the same outer peripheral surface, a plurality of locking windows are formed in the outer peripheral wall of one main body case, and the inner wall of one main body case is formed inside the outer peripheral wall of the other main body case. forming a fitting wall fits inside the peripheral wall, the rotation sensor of the structure projecting from the lockable locking projection in the locking window to the fitting wall is that known.
JP-A-10-197287 (page 3, FIG. 1)

  However, in the conventional rotation sensor described above, in order to securely fit the fitting projection 7 of the rotor 2 into the fitting window 6 of the sleeve 3, as shown in FIG. A minute gap g must be set in advance between the end face of the lower end 7b of the protrusion 7 and the end face of the fitting window 6 provided on the sleeve 3 side facing the lower end 7b of the fitting protrusion 7. .

  For this reason, the gap D between the opposing surfaces of the flange 2b of the rotor 2 and the flange 3b of the sleeve 3 increases by the gap g, the sleeve 3 moves in the axial direction indicated by the arrow in FIG. (Direction) is further increased in addition to the clearance d. Further, since the clearance in the axial direction (vertical direction) of the rotor 2 increases, the inclination of the rotation axis of the rotor 2 increases. The increase in the backlash and inclination in the axial direction of the rotor 2 results in an increase in detection error of a sensor attached between the rotor 2 and the stator 1. The structure for fixing the main body case divided into two parts described in Patent Document 1 also has the same problem as described above.

  The present invention has been made in view of the above-described points, and reduces the gap between the stator and the rotor rotatably supported by the stator, thereby suppressing rattling and tilting of the rotor and reducing the detection error of the sensor. An object of the present invention is to provide a rotation sensor designed to be illustrated.

In order to achieve the above object, the rotation sensor according to the present invention comprises:
A stator provided with a through-hole that is fixed independently of the rotating shaft and through which the rotating shaft passes;
A cylindrical portion that is disposed on one side of the through hole of the stator, is inserted into the rotation shaft so as to be rotatable integrally with the rotation shaft, and is opposed to the peripheral portion of the through hole at the end of the cylindrical portion. A rotor having a flange having a diameter larger than that of the through hole;
A cylindrical portion that is fitted to the inside of the cylindrical portion of the rotor from the other side of the through hole of the stator, and the peripheral portion of the through hole is opposed to the peripheral portion of the through hole at the end of the cylindrical portion. A sleeve that has a larger diameter flange, and the flange and the rotor flange hold the rotor rotatably with a predetermined clearance in the stator;
In the rotation sensor provided with the cylindrical portion of the rotor and the cylindrical portion of the sleeve and fixing means for fixing them,
The fixing means includes
A fitting protrusion and an engaging protrusion formed on the inner peripheral surface of the cylindrical portion of the rotor at intervals in the circumferential direction;
The cylindrical portion of the sleeve is formed along the circumferential direction corresponding to the fitting protrusion and the engaging protrusion, and the cylindrical portion of the sleeve is inserted into the cylindrical portion of the rotor up to the predetermined clearance. Ri Do from the engaging groove engaging portion and the engaging projection is engaged to the engaging projection and the fitting when rotated by a predetermined angle,
The cylindrical portion of the sleeve has guide grooves into which the fitting protrusion and the engaging protrusion are inserted so that the cylindrical portion can be inserted into the cylindrical portion of the rotor up to the predetermined clearance position. It is formed from the opening end of to a predetermined position,
The fitting protrusion and the engaging protrusion formed on the cylindrical portion of the rotor are fitted and engaged with the fitting portion and the engaging groove from the guide groove by rotating the sleeve, respectively. And
The fitting protrusion has a substantially wedge shape protruding inward from the inner peripheral surface along the circumferential direction from the rotation start position of the sleeve toward the rotation stop position,
The fitting portion is formed in a tongue-like shape by a slit extending in the circumferential direction and connected to the guide groove and a terminal portion of the guide groove, and the fitting protrusion is fitted into the fitting portion. A fitting window is formed, and is bent and deformed inward by the wedge-shaped fitting protrusion protruding from the guide groove with the rotation of the sleeve, so that the insertion of the fitting protrusion into the fitting window is allowed. , The fitting window and the fitting protrusion engage at the rotation stop position of the sleeve,
The engagement groove is formed to extend in the circumferential direction continuously to the end portion of the guide groove, and the engagement protrusion is engaged from the guide groove with the rotation of the sleeve, and the rotation of the sleeve The cylindrical portion of the rotor and the cylindrical portion of the sleeve are fixed by being brought into contact with the end of the engaging groove at the stop position .

  A rotor is arranged on one side (lower side) of the through hole of the stator, a flange of the rotor is opposed to the peripheral part of the through hole, and a sleeve is arranged on the other side (upper side) of the through hole of the stator. The sleeve is opposed to the flange of the sleeve, and the cylindrical portion of the sleeve is inserted into the cylindrical portion of the rotor to a position having a predetermined clearance between the flange of the sleeve and the peripheral portion of the through hole. Next, the sleeve is rotated by a predetermined angle in the circumferential direction with respect to the rotor, and the fitting protrusion formed on the inner circumferential surface of the cylindrical portion of the rotor is fitted into the fitting portion formed on the cylindrical portion of the sleeve. At the same time, the engaging protrusion formed on the inner peripheral surface of the cylindrical portion of the rotor is engaged with and fixed to the engaging groove formed on the cylindrical portion of the sleeve.

  In the sleeve, the position at which the cylindrical portion is inserted to the position where the cylindrical portion of the rotor has a predetermined clearance is the rotation start position, the engaging protrusion comes into contact with the terminal end of the engaging groove, and the fitting protrusion is fitted The position fitted to the part is the rotation stop position.

  The fitting protrusion and the engaging protrusion cooperate to increase the gap between the rotor and the stator by the gap necessary to securely fit the fitting protrusion and the fitting portion. This suppresses the movement and inclination of the rotor in the axial direction and keeps it at a predetermined clearance, and prevents the sleeve from moving and shifting in the circumferential direction. Further, the rotor can rotate smoothly with a predetermined clearance with respect to the stator. Thereby, it is possible to prevent an increase in detection error of a sensor arranged between the stator and the rotor.

Further, when the cylindrical portion of the sleeve is inserted into the cylindrical portion of the rotor, the fitting protrusions and the engaging protrusions formed on the inner surface of the cylindrical portion of the rotor are inserted into the guide grooves formed in the cylindrical portion of the sleeve. The cylindrical portion is inserted into the cylindrical portion of the rotor to a position having a predetermined clearance. Next, the sleeve is rotated to fit the fitting projection from the guide groove to the fitting portion, and the engagement projection is engaged from the guide groove to the engagement groove. As a result, a predetermined clearance can be secured between the stator and the rotor, and the sleeve can be fixed to the rotor without rattling.

Further, since the fitting portion formed on the cylindrical portion of the sleeve has a tongue-like shape, the fitting portion can be bent and displaced inward in the radial direction of the cylindrical portion. Pull out from the guide groove, enter between the fitting part and the inner peripheral surface of the cylindrical part of the rotor, enter the fitting window while bending inward of the cylindrical part, and the end part is opposite the fitting window at the rotation stop position of the sleeve It is latched by the end surface to do. At the same time, the engaging protrusion is engaged with the engaging groove from the guide groove and comes into contact with the end position of the engaging groove at the rotation stop position of the sleeve.

  At the rotation stop position of the sleeve, the end face of the fitting projection is locked to the opposite end face of the fitting window, and one end face (upper end face) abuts the corresponding end face (upper end face) of the fitting window. When the joint protrusion is engaged with the engaging groove and abuts against the end surface of the engaging groove, the sleeve moves in the circumferential direction with respect to the rotor, or the sleeve and the rotor are rattled or inclined in the axial direction. It is prevented. Thereby, the clearance gap between a rotor and a stator is ensured by predetermined | prescribed clearance. Further, the sleeve is prevented from falling off the rotor.

Moreover, the rotation sensor according to claim 2 of the present invention is the rotation sensor according to claim 1 ,
The fitting protrusion and the engaging protrusion formed on the inner peripheral surface of the cylindrical portion of the rotor, and the fitting portion and the engaging groove formed on the cylindrical portion of the sleeve are in the axial direction of these cylindrical portions. It is characterized by being provided at different positions.

  The fitting protrusion and the engaging protrusion, and the fitting part and the engaging groove are located at different positions with respect to the axial direction of the cylindrical portion. Even when the fitting projection is about to shift in the axial direction of the cylindrical portion within the fitting window, the sleeve is prevented from moving or tilting with respect to the rotor in cooperation with the fitting projection. The predetermined clearance is ensured.

Moreover, the rotation sensor according to claim 3 of the present invention is the rotation sensor according to claim 1 or 2 ,
A plurality of the fixing means are formed at predetermined intervals along the circumferential direction in each cylindrical portion of the rotor and the sleeve.

  By providing fixing means for fixing the cylindrical portion of the rotor and the cylindrical portion of the sleeve at predetermined intervals along the circumferential direction of these cylindrical portions, preferably at equal intervals, the inclination of the sleeve with respect to the rotor and the axial direction The backlash can be extremely reduced, and a gap between the stator and the rotor can be ensured with a predetermined clearance.

  According to the present invention, the fitting protrusion and the engagement protrusion formed on the cylindrical portion of the rotor are fitted and engaged with the fitting portion and the engagement groove formed along the circumferential direction on the cylindrical portion of the sleeve. As a result, the movement and inclination of the sleeve in the axial direction can be reduced, and the backlash of the rotor can be extremely reduced.

  In addition, even with a mechanism that fits the fitting protrusion formed on the cylindrical portion of the sleeve into the fitting portion formed on the cylindrical portion of the rotor, the play and inclination caused by the gap for these fittings are extremely small. Accordingly, an increase in detection error of a sensor mounted between the stator and the rotor can be reduced.

  Further, the movement of the sleeve in the rotational direction with respect to the rotor is restricted by the fitting protrusion and the fitting portion, and the engagement protrusion and the engagement groove, and the sleeve can be prevented from falling off the rotor.

  Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the rotation sensor 11 is for detecting a rotation direction and a rotation angle of a rotation shaft, for example, a steering shaft of a vehicle, and forms a part of a case fixed to the vehicle body side. A rotor 13 disposed on one side (lower side), a sleeve 14 disposed on the other side (upper side) of the stator 12, fixed to the rotor 13, and rotatably held with respect to the stator 12, and the stator And a sensor (not shown) that is attached between the rotor 12 and the rotor 13 and detects the rotation direction and rotation angle of the steering shaft.

  The stator 12 is flat at least at a portion where the rotor 13 and the sleeve 14 are mounted, and has a through hole 12a through which the steering shaft as a rotating shaft passes. The rotor 13 includes a cylindrical portion 13a and a flange 13b formed at the upper end (one end) of the cylindrical portion 13a as shown in FIG. The cylindrical portion 13a is rotatably mounted integrally with the steering shaft through which the steering shaft is inserted. Further, the flange 13b has a larger diameter than the through hole 12a, and can be opposed to a peripheral portion on the lower side (one side) of the through hole 12a.

  The sleeve 14 includes a cylindrical portion 14a and a flange 14b formed at the upper end (one end) of the cylindrical portion 13a. The cylindrical portion 14a can be fitted inside the cylindrical portion 13a of the rotor 13 and the steering shaft can be inserted therethrough. The cylindrical portion 14 a is set shorter than the cylindrical portion 13 a of the rotor 13. Further, the flange 13b has a larger diameter than the through hole 12a, can be opposed to the peripheral portion on the upper side (the other side) of the through hole 12a, and has the same diameter as the flange 13b of the rotor 13.

  The cylindrical portion 13a of the rotor 13 and the cylindrical portion 14a of the sleeve 14 are provided with fixing means 15 for fixing them. The fixing means 15 includes a fitting protrusion 16 and an engaging protrusion 17 protruding from the inner peripheral surface 13 c of the cylindrical portion 13 a of the rotor 13, and a fitting protrusion 16 and an engaging protrusion on the cylindrical portion 14 a of the sleeve 14. The fitting portion 18 and the engagement groove 19 formed corresponding to the portion 17, and the fitting projection 16 and the guide projections 20 and 21 for guiding the engagement projection 17 to the fitting portion 18 and the engagement groove 19. Etc. are formed.

  The fitting protrusion 16 and the engagement protrusion 17 are spaced apart from each other in the circumferential direction on the inner peripheral surface 13c of the cylindrical portion 13a and are different along the axial direction of the cylindrical portion 13a, as shown in FIG. It is formed with a step. As shown in FIG. 2 in an enlarged manner, the fitting protrusion 16 has an inner peripheral surface 16a that bulges inwardly from the inner peripheral surface 13c of the cylindrical portion 13a in a taper shape inward along the circumferential direction, It is substantially wedge-shaped when viewed from the opening end side of the cylindrical portion 13a. The fitting protrusion 16 has a front end portion 16b that is flush with the inner peripheral surface 13c of the cylindrical portion 13a, and a rear end portion 16c that is substantially perpendicular to the inner peripheral surface 13c. Moreover, the protrusion 17 for engagement is made into the column shape, for example.

  The height of the fitting protrusion 16 from the inner peripheral surface 13 c (the height of the rear end portion 16 c) is set to be the same as or slightly lower than the thickness of the cylindrical portion 14 a of the sleeve 14. The height of the engaging projection 17 is set to be the same as or slightly lower than the thickness of the cylindrical portion 14 a of the sleeve 14, similarly to the fitting projection 16. Thus, when the cylindrical portion 14a of the sleeve 14 is fitted inside the cylindrical portion 13a of the rotor 13, the fitting projection 16 and the engagement projection 17 are located on the inner side of the inner peripheral surface 14c of the cylindrical portion 14a. It does not protrude.

  The guide grooves 20 and 21 of the cylindrical portion 14a are formed from the lower end to a predetermined position along the axial direction of the cylindrical portion 14a at positions corresponding to the fitting projections 16 and the engagement projections 17, respectively. The part 16 and the protrusion 17 for engagement can be inserted from the lower end side opening. One end of the slit 22 is connected to the upper end portion (terminal portion) of the guide groove 20 to form an inverted L shape. The slit 22 is formed with a predetermined length along the circumferential direction of the cylindrical portion 14a.

  The guide groove 20 and the slit 22 having an inverted L shape form a tongue-like fitting portion 18 having a long rectangular shape in the circumferential direction at the lower portion of the cylindrical portion 14a, and a rectangular shape that is long in the circumferential direction at the center thereof. A shaped fitting window 24 is formed. The fitting window 24 is set to a size that allows the fitting protrusion 16 to be fitted. The fitting portion 18 can bend elastically in the radial direction of the cylindrical portion 14a with the free end side (the guide groove 20 side) as a root portion from the end position of the slit 22 to the lower end in the axial direction of the cylindrical portion 14a. It is said that.

  One end of the engagement groove 19 is connected to the upper end portion (terminal portion) of the guide groove 21. The engagement groove 19 is formed with a predetermined length along the circumferential direction of the cylindrical portion 14a. The engagement groove 19 is set to have such a width that the engagement protrusion 17 is press-fitted with an appropriate force. Further, as shown in FIG. 2, the inner corner 19 a of the connecting portion of the engaging groove 19 and the guide groove 21 is chamfered, and the engaging protrusion 17 easily enters the engaging groove 19 from the guide groove 21. ing.

  The guide groove 21 faces the flange 13b of the rotor 13 and the through hole 12a of the stator 12 when the engaging protrusion 17 is inserted from the lower end opening of the guide groove 21 and comes into contact with the upper end (end portion). The length is set such that a predetermined clearance d is ensured between the peripheral edge portion. The position where the engaging projection 17 abuts on the upper end (terminal portion) of the guide groove 21 is the rotation start position of the sleeve 14, and when the sleeve 14 is rotated with respect to the rotor 13, the engaging projection 17 can be engaged with the engagement groove 19, and the fitting protrusion 16 can be pulled out of the guide groove 20 and fitted into the fitting window 24 of the fitting portion 18. Then, the rear end portion 16c of the fitting projection 16 is brought into contact with and locked with the opposing end surface of the fitting window 24, and the engagement projection 17 is brought into contact with and locked with the end surface of the engagement groove 19 The position becomes the rotation stop position of the sleeve 14.

  In this way, the fixing means 15 is formed. And this fixing means 15 is formed in the cylindrical part 13a of the rotor 13, and the cylindrical part 14a of the sleeve 14 in multiple places, for example, three places at predetermined intervals along the circumferential direction. The stator 12, the rotor 13, and the sleeve 14 are formed of a synthetic resin member. The stator 12 is formed of a synthetic resin member such as PBT (polybutylene laphthalate), and the rotor 13 and the sleeve 14 have a small friction coefficient and a small sliding resistance (easy to slide) such as POM (polyacetal). It is formed of a synthetic resin member.

  The procedure for assembling the rotation sensor 11 having the above configuration will be described below. As shown in FIGS. 1 and 3, the rotor 13 is disposed below the through hole 12a of the stator 12, and the flange 13b is brought into contact with the opposite lower peripheral portion of the through hole 12a. Next, the cylindrical portion 14 a of the sleeve 14 is inserted from above the through hole 12 a of the stator 12. At this time, the fitting protrusions 16 and the engaging protrusions 17 formed on the cylindrical portion 13 a of the rotor 13 are inserted into the guide grooves 20 and 21 formed on the cylindrical portion 14 a of the sleeve 14. Then, as shown in FIG. 4, the engaging protrusion 17 is inserted until it is in contact with and locked to the upper end (terminal portion) of the guide groove 21.

  Next, the sleeve 14 is rotated in the direction indicated by the arrow in FIG. With the rotation of the sleeve 14, the fitting projection 16 comes out of the guide groove 20, and the tip 16b is below the fitting portion 18, that is, between the outer peripheral surface of the fitting portion 18 and the inner peripheral surface of the cylindrical portion 13a. The fitting portion 18 enters the fitting window 24 while being bent and deformed inwardly in the radial direction of the cylindrical portion 14a (while being warped back), and the engaging protrusion 17 is moved from the guide groove 21 to the engaging groove. Is engaged (press-fit). Then, as shown in FIG. 5, when the engaging protrusion 17 is brought into contact with the end surface of the engaging groove 19 and is locked, the engaging protrusion 16 is fitted into the fitting window 24, and the rear end portion 16c is brought into contact with and locked to the opposite end surface of the fitting window 24, and the upper end surface is brought into contact with and locked to the opposite end surface of the fitting window 24. Thereby, the sleeve 14 is fixed to the rotor 13 with the stator 12 interposed therebetween.

  The guide groove 21 has a predetermined clearance d between the flange 13b of the rotor 13 and the opposing peripheral edge of the through hole 12a of the stator 12 when the engaging protrusion 17 abuts on the upper end (terminal portion). The engagement groove 19 is formed along the circumferential direction from the upper end portion of the guide groove 21, and the engagement protrusion 17 abuts on the end portion of the engagement groove 19. Engaged, and the upper end surface of the fitting projection 16 is abutted and locked to the opposite end surface of the fitting window 24, so that it is necessary for fitting between the fitting projection 16 and the fitting window 24. The play due to the minute gap g is almost removed, and the gap in the axial direction becomes the clearance d, and the increase in play is suppressed.

  As a result, a predetermined clearance d is ensured between the flange 14b of the sleeve 14 and the peripheral edge of the stator 12 facing the through hole 12a, and wasteful play is eliminated, so that the sleeve 14 extends in the axial direction with respect to the rotor 13. Moving or tilting is greatly reduced. Further, the engagement protrusion 17 abuts on the end surface of the engagement groove 19, and the rear end portion 16 c of the engagement protrusion 16 abuts on and engages with the opposite end surface of the engagement window 24, so that the sleeve The 14 cylindrical portions 14 a are prevented from moving in the circumferential direction with respect to the cylindrical portion 13 a of the rotor 13, and the sleeve 14 is prevented from being detached from the rotor 13.

  In FIG. 5, the clearance d is depicted as a gap between the upper surface of the peripheral edge of the through hole 12a of the stator 12 and the lower surface of the flange 14b of the sleeve 14, but the upper surface of the flange 13b of the rotor 13 and the through hole 12a. It is good also as clearance between a peripheral part lower surface. Or it is good also as the clearance between the flange 13b of the rotor 13 of both sides, the flange 14b of the sleeve 14, and the peripheral part both surfaces which the through-hole 12a opposes. In this case, the sum of the gaps on both sides of the through hole 12a becomes the predetermined clearance d.

  Since the rotor 13 and the sleeve 14 are formed of a synthetic resin member that has a small sliding resistance and is easy to slide, the rotor 13 and the sleeve 14 can be smoothly rotated with respect to the stator 12. Between the stator 12 and the rotor 13, a sensor (not shown) for detecting the rotation direction and the rotation angle of the rotor 13, that is, the rotation shaft on which the rotor 13 is rotatably mounted integrally is attached.

  The rotor 13 and the sleeve 14 are significantly reduced from moving or tilting with respect to the stator 12 in the axial direction, and the sleeve 14 is prevented from moving in the circumferential direction with respect to the rotor 13. The increase in detection error is greatly suppressed, and as a result, the detection accuracy is improved. This is particularly suitable when a sensor of a type that reacts sensitively to the axial backlash, inclination, circumferential backlash, etc. of the rotor 13 and greatly affects the detection accuracy is used.

  As this sensor, for example, a conductive metal plate (sensing unit) whose width varies along the circumferential direction is provided on the flange 13b of the rotor 13, and a detection coil is provided on the stator 12 side to detect a change in impedance due to an eddy current. A sensor that changes the magnetic flux density in the circumferential direction on the rotor 13 side, a sensor that detects a change in magnetic field by providing a Hall element on the stator 12 side, or a gear on the rotor 13 side, A type in which a gear that meshes with the gear and rotates is provided on the stator side, a magnet is provided in the gear, and an MR element that detects the magnetic flux of the magnet that rotates according to the rotation of the rotor 13 is provided corresponding to the center of the gear. Sensor or a light emitting / receiving element that provides a disc with slits formed at predetermined intervals along the circumferential direction on the rotor side and photoelectrically detects the slits on the fixed side Those types sensors, etc. of the various provided are applicable in the present invention.

  The stator 12, the rotor 13, and the sleeve 14 are accommodated in a case (not shown) to constitute the rotation sensor 11. In this rotation sensor 11, a stator 12 is fixed to a fixed side, for example, the vehicle body side, and a steering shaft as a rotation shaft is inserted into the cylindrical portion 13a of the rotor 13, the through hole 12a of the stator 12, and the cylindrical portion 14a of the sleeve 14. And the cylindrical part 13a of the rotor 13 is rotatably attached integrally with the steering shaft by a coupling mechanism (not shown). As the coupling mechanism, for example, there is a coupling mechanism formed by serrations formed along the axial direction on the outer peripheral surface of the steering shaft and serrations formed along the axial direction at the lower portion of the inner peripheral surface of the cylindrical portion 13a.

  In the above-described embodiment, the case where the engaging protrusion 17 is engaged with the engaging groove 19 is described. However, the present invention is not limited to this, and the engaging protrusion 17 may be press-fitted into the engaging groove 19. good.

  In the above embodiment, the case where the rotation sensor 11 is applied to a rotation sensor that detects the rotation direction and rotation angle of the steering shaft of the vehicle has been described. However, the present invention is not limited to this, and the rotation direction and rotation angle of various rotation shafts are described. Or it is possible to apply to the apparatus which detects rotation speed.

It is an assembly perspective view of the rotation sensor concerning the present invention. It is an enlarged view of the rotation sensor shown in FIG. FIG. 3 is a sectional view taken along arrows III-III of the stator and rotor of the rotation sensor shown in FIG. 1. It is explanatory drawing in the case of assembling the rotation sensor shown in FIG. FIG. 5 is a cross-sectional view taken along the arrow line VV in a state where the rotation sensor shown in FIG. 4 is assembled. It is an assembly perspective view of the conventional rotation sensor. It is sectional drawing which follows the arrow VII-VII of the stator and rotor of a rotation sensor shown in FIG. FIG. 7 is an assembled perspective view of the rotation sensor shown in FIG. 6. It is sectional drawing which follows the arrow IX-IX of the rotation sensor shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stator 1a Through-hole 2 Rotor 2a Cylindrical part 2b Flange 3 Sleeve 3a Cylindrical part 3b Flange 4 Fixing means 5 Extension part 6 Fitting window 7 Fitting protrusion 7a Upper end part 7b Lower end part 8 Guide part 11 Rotation sensor 12 Stator 12a Through hole 13 Rotor 13a Cylindrical portion 13b Flange 13c Inner peripheral surface 14 Sleeve 14a Cylindrical portion 14b Flange 14c Inner peripheral surface 15 Fixing means 16 Fitting protrusion 16a Inner peripheral surface 16b Front end portion 16c Rear end portion 17 Engaging protrusion 18 Fitting Joint 19 Engagement groove 19a Inner corner 20, 21 Guide groove 22 Slit 24 Fitting window d Clearance g Small gap D Gap

Claims (3)

A stator provided with a through-hole that is fixed independently of the rotating shaft and through which the rotating shaft passes;
A cylindrical portion that is disposed on one side of the through hole of the stator, is inserted into the rotation shaft so as to be rotatable integrally with the rotation shaft, and is opposed to the peripheral portion of the through hole at the end of the cylindrical portion. A rotor having a flange having a diameter larger than that of the through hole;
A cylindrical portion that is fitted to the inside of the cylindrical portion of the rotor from the other side of the through hole of the stator, and the peripheral portion of the through hole is opposed to the peripheral portion of the through hole at the end of the cylindrical portion. A sleeve that has a larger diameter flange, and the flange and the rotor flange hold the rotor rotatably with a predetermined clearance in the stator;
In the rotation sensor provided with the cylindrical portion of the rotor and the cylindrical portion of the sleeve and fixing means for fixing them,
The fixing means includes
A fitting protrusion and an engaging protrusion formed on the inner peripheral surface of the cylindrical portion of the rotor at intervals in the circumferential direction;
The cylindrical portion of the sleeve is formed along the circumferential direction corresponding to the fitting protrusion and the engaging protrusion, and the cylindrical portion of the sleeve is inserted into the cylindrical portion of the rotor up to the predetermined clearance. Ri Do from the engaging groove engaging portion and the engaging projection is engaged to the engaging projection and the fitting when rotated by a predetermined angle,
The cylindrical portion of the sleeve has guide grooves into which the fitting protrusion and the engaging protrusion are inserted so that the cylindrical portion can be inserted into the cylindrical portion of the rotor up to the predetermined clearance position. It is formed from the opening end of to a predetermined position,
The fitting protrusion and the engaging protrusion formed on the cylindrical portion of the rotor are fitted and engaged with the fitting portion and the engaging groove from the guide groove by rotating the sleeve, respectively. And
The fitting protrusion has a substantially wedge shape protruding inward from the inner peripheral surface along the circumferential direction from the rotation start position of the sleeve toward the rotation stop position,
The fitting portion is formed in a tongue-like shape by a slit extending in the circumferential direction and connected to the guide groove and a terminal portion of the guide groove, and the fitting protrusion is fitted into the fitting portion. A fitting window is formed, and is bent and deformed inward by the wedge-shaped fitting protrusion protruding from the guide groove with the rotation of the sleeve, so that the insertion of the fitting protrusion into the fitting window is allowed. , The fitting window and the fitting protrusion engage at the rotation stop position of the sleeve,
The engagement groove is formed to extend in the circumferential direction continuously to the end portion of the guide groove, and the engagement protrusion is engaged from the guide groove with the rotation of the sleeve, and the rotation of the sleeve A rotation sensor , wherein the cylindrical portion of the rotor and the cylindrical portion of the sleeve are fixed by being brought into contact with the end of the engaging groove at a stop position . The fitting protrusion and the engaging protrusion formed on the inner peripheral surface of the cylindrical portion of the rotor, and the fitting portion and the engaging groove formed on the cylindrical portion of the sleeve are in the axial direction of these cylindrical portions. It characterized that you have provided at different positions in the rotation sensor according to claim 1. It said fixing means is characterized that you have formed a plurality at predetermined intervals along the circumferential direction in the cylindrical portion of the rotor and the sleeve, the rotation sensor according to claim 1 or claim 2.

Images