JP2006201025A - Rotation angle detection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To heighten detection accuracy of a rotation angle detection apparatus by excluding the effects of backlash of gears. <P>SOLUTION: The rotation angle detection apparatus 11 includes a main pulley 14 provided for the outer circumference of a steering shaft 15; first and second sub-pulleys 20A and 20B connected to the main pulley 14 via a cog belt 21; and first and second rotation angle sensors 18A and 18B for detecting each rotation angle of both sub-pulleys 20A and 20B and detects the rotation angle of the steering shaft 15 on the basis of output of both rotation angle sensors 18A and 18B. Since the use of the cog belt 21 eliminates the influence of backlash caused in the case that the main pulley 14 and the first and second sub-pulleys 20A and 20B are interlocked via gears, it is possible to accurately interlock rotation angles of three pulleys 14, 20A and 20B while suppressing the occurrence of noise. Since a tensioner 22 provides a tensile force for the cog belt 21, it is possible to prevent the cog belt 21 from loosening and further heighten accuracy in rotation angle detection. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention provides a main ring provided on the outer periphery of a rotating shaft, a plurality of sub-rings that rotate in conjunction with the rotation of the main ring, and a plurality of rotations that detect rotation angles of the plurality of sub-rings, respectively. The present invention relates to a rotation angle detection device that includes an angle sensor and detects a rotation angle of the shaft based on outputs of the plurality of rotation angle sensors.

A steering angle sensor that detects a rotation angle of a steering shaft based on a change in a magnetic field associated with rotation of a pair of driven gears by meshing a pair of driven gears each having a magnet with an annular drive gear fixed to the steering shaft. This is known from US Pat.
JP 2000-159037 A

  By the way, in the above-mentioned conventional one, the rotation angle of the steering shaft is detected based on the rotation angles of the pair of driven gears meshed with the annular drive gear, so that the steering shaft rotates in the right turning direction and the left turning The rotational angle of the driven gear changes due to the backlash of the gear when rotating in the direction, which causes a problem that the detection accuracy of the rotational angle of the steering shaft is lowered. In addition, there is a problem that the degree of freedom of the position of the pair of driven gears relative to the position of the annular drive gear is limited, and noise is generated due to the influence of gear backlash.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to improve the detection accuracy of a rotation angle detection device by eliminating the influence of gear backlash.

  In order to achieve the above object, according to the first aspect of the present invention, a main ring provided on the outer periphery of the rotating shaft, and a plurality of sub-rings rotating in conjunction with the rotation of the main ring, A rotation angle detecting device that detects a rotation angle of the shaft based on outputs of the plurality of rotation angle sensors, the rotation angle detecting device comprising: a plurality of rotation angle sensors that respectively detect rotation angles of the plurality of sub-annular rings; A rotation angle characterized by winding an endless belt around the ring and the plurality of sub-rings, rotating the plurality of sub-rings in conjunction with rotation of the main ring, and applying tension to the endless belt with a tensioner A detection device is proposed.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the tensioner urges the endless belt from the inner peripheral side to the outer peripheral side to give tension. A detection device is proposed.

  According to a third aspect of the present invention, in addition to the configuration of the first aspect, the tensioner urges the endless belt from the outer peripheral side to the inner peripheral side to provide tension. A detection device is proposed.

  According to the invention described in claim 4, in addition to the configuration of claim 1, the first support body that supports the first rotation shaft of the first sub-annular ring and the second rotation shaft of the second sub-ring ring. The tensioner is urged in a direction in which the first and second support members are separated from each other, and tension is applied to the endless belt. There is proposed a rotation angle detection device characterized by comprising an elastic body that provides the.

  According to the invention described in claim 5, in addition to the configuration of any one of claims 1 to 4, the endless belt is a cog belt that engages with the main ring and the sub ring in an uneven manner. A rotation angle detection device characterized by the above is proposed.

  The main pulley 14 of the embodiment corresponds to the pulley of the present invention, the steering shaft 15 of the embodiment corresponds to the shaft of the present invention, and the first and second rotation angle sensors 18A and 18B of the embodiment are of the present invention. Corresponding to the rotation angle sensor, the first and second auxiliary pulleys 20A and 20B of the embodiment correspond to the auxiliary ring of the present invention, the cog belt 21 of the embodiment corresponds to the endless belt of the present invention, and the first of the embodiments. The first and second swing arms 34A and 34B correspond to the first and second supports of the present invention, and the leaf spring 35 of the embodiment corresponds to the elastic body of the present invention.

  According to the configuration of claim 1, a plurality of sub-rings that rotate around the rotation of the main ring by winding an endless belt around the main ring and the plurality of sub-rings provided on the outer periphery of the rotating shaft. Since the rotation angle of the shaft is detected by detecting the rotation angle of the shaft, the rotation angle of the shaft is detected. The rotation angle of the main ring can be accurately linked to the rotation angle of the sub ring while suppressing the occurrence, and the sub ring relative to the main ring is compared to the case where the main ring and the sub ring are linked with gears. The degree of freedom in the layout of the ring is improved. In addition, since tension is applied to the endless belt by the tensioner, it is possible to prevent the endless belt from loosening and to link the rotation angle of the sub-ring with the rotation angle of the main ring with higher accuracy.

  According to the configuration of the second aspect, since the tensioner urges the endless belt from the inner peripheral side to the outer peripheral side to apply tension, the tensioner can be arranged on the inner peripheral side of the endless belt to save space. it can.

  According to the configuration of the third aspect, the tensioner urges the endless belt from the outer peripheral side to the inner peripheral side to apply tension, so that the winding angle of the endless belt with respect to the main ring or the sub ring is increased to increase the main circle. The rotation angle of the secondary ring can be linked with the rotation angle of the ring with higher accuracy.

  According to the structure of Claim 4, the 1st support body which supports the 1st rotating shaft of a 1st subannular ring, and the 2nd support body which supports the 2nd rotating shaft of a 2nd subannular ring mutually approach and separate. Since the first and second support bodies were urged away from each other by a tensioner, the first and second sub-annular rings were simultaneously urged by one tensioner. Tension can be reliably applied to the endless belt.

  According to the configuration of the fifth aspect, since the endless belt is constituted by the cog belt that engages with the main ring and the sub ring, the main belt and the sub ring are prevented from slipping with respect to the main ring and the sub ring. The rotation angle of the sub-ring can be linked more accurately to the rotation angle of the ring.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on examples of the present invention shown in the accompanying drawings.

  1 to 3 show a first embodiment of the present invention. FIG. 1 is an overall plan view of a rotation angle detecting device for detecting the rotation angle of a steering shaft, and FIG. 2 is a sectional view taken along line 2-2 of FIG. 3 is a cross-sectional view taken along line 3-3 of FIG.

  A rotation angle detection device 11 for detecting the rotation angle of a steering wheel of an automobile is provided on a substrate 12 fixed to the vehicle body. An annular main pulley 14 is rotatably supported on the substrate 12 via a needle bearing 13. The outer periphery of the cylindrical steering shaft 15 is spline fitted 16 to the inner periphery of the main pulley 14. A first rotation shaft 19A protrudes downward from a first rotation angle sensor 18A fixed to the upper surface of the first bracket 17A fixed to the substrate 12, and the first sub pulley 20A is supported by the first rotation shaft 19A. Similarly, the second rotation shaft 19B protrudes downward from the second rotation angle sensor 18B fixed to the upper surface of the second bracket 17B fixed to the substrate 12, and the second sub pulley 20B is supported by the second rotation shaft 19B. Is done.

  A cog belt 21 is wound around the main pulley 14 and the first and second auxiliary pulleys 20A and 20B. The main pulley 14 and the first and second auxiliary pulleys 20A, 20B are provided with frustoconical protrusions 14a ..., 20a ... on the outer periphery, and these protrusions 14a ..., 20a ... are in holes 21a ... formed in the cog belt 21. Engage.

  The tensioner 22 disposed between the first and second auxiliary pulleys 20A and 20B includes a guide block 23 fixed to the substrate 12, a guide rod 24 slidably supported on the guide block 23, and a tip of the guide rod 24. A pulley holder 25 fixed to the pulley holder 25, a tensioner pulley 27 rotatably supported on the pulley holder 25 via a support shaft 26, and a coil spring 28 that biases the guide rod 24 in a direction in which the tensioner pulley 27 is pressed against the inner peripheral surface of the cog belt 21. It consists of.

  Next, the operation of the first embodiment having the above configuration will be described.

  When the driver operates the steering handle to rotate the steering shaft 15, the main pulley 14 that is spline fitted 16 to the steering shaft 15 rotates, and the rotation of the main pulley 14 is caused by the first auxiliary pulley 20 </ b> A and the second pulley via the cog belt 21. It is transmitted to the sub pulley 20B. Since the first and second auxiliary pulleys 20A and 20B have different diameters, the rotation angle of the first auxiliary pulley 20A detected by the first rotation angle sensor 18A and the second auxiliary pulley 20B detected by the second rotation angle sensor 18B. The rotation angle of the main pulley 14, that is, the steering shaft 15, is detected from the combination of these two rotation angles.

  When the main pulley 14 and the first and second auxiliary pulleys 20A and 20B are interlocked with a gear instead of the cog belt 21, the first auxiliary pulley 20A is rotated when the main pulley 14 rotates clockwise and counterclockwise due to the influence of gear backlash. And the rotation angle of the 2nd sub pulley 20B changes, and there exists a problem that the detection accuracy of the rotation angle detection apparatus 11 falls. However, in this embodiment, the main pulley 14 and the first and second auxiliary pulleys 20A and 20B are interlocked by the cog belt 21, so that the influence of gear backlash is eliminated and the detection accuracy of the rotation angle detection device 11 is improved. Generation of noise can be suppressed.

  Further, in the interlocking with the gear, the degree of freedom of the arrangement of the first and second auxiliary pulleys 20A and 20B with respect to the main pulley 14 is limited, but by using the cog belt 21, the first and second auxiliary pulleys 20A and 20B The degree of freedom of arrangement is improved. In addition, since the main pulley 14 and the first and second auxiliary pulleys 20A and 20B and the cog belt 21 are engaged with each other, the cog belt 21 is prevented from slipping and the detection accuracy of the rotation angle detecting device 11 can be further improved. .

  Further, the guide rod 24 is urged by the elastic force of the coil spring 28 and the tensioner pulley 27 is pressed against the inner peripheral surface of the cog belt 21 to apply tension. Therefore, the detection accuracy of the rotation angle detection device 11 due to loosening of the cog belt 21 is improved. A decrease can be prevented. Further, since the tensioner 22 urges the cog belt 21 from the inner peripheral side to the outer peripheral side to apply tension, the tensioner 22 can be arranged on the inner peripheral side of the cog belt 21 to save space.

  Next, a second embodiment of the present invention will be described with reference to FIG.

  The second embodiment is different from the first embodiment in the structure of the tensioner 22. The tensioner 22 of the second embodiment has one end of a torsion spring 30 wound around a pin 29 planted on the substrate 12 locked to a spring receiver 31 and a support shaft provided at the other end of the torsion spring 30. A tensioner pulley 27 rotatably supported on the belt 32 is configured to elastically contact the inner peripheral surface of the cog belt 21. Also according to the second embodiment, it is possible to achieve the same operation and effect as the first embodiment described above.

  Next, a third embodiment of the present invention will be described with reference to FIG.

  In the third embodiment, the arrangement position of the tensioner 22 is different from that of the first embodiment. That is, in the first embodiment, the tensioner 22 is disposed on the inner peripheral side of the cog belt 21, whereas in the third embodiment, the tensioner 22 having the same structure is disposed on the outer peripheral side of the cog belt 21. According to the third embodiment, in addition to the operational effects of the first embodiment, the winding angle of the cog belt 21 with respect to the first and second auxiliary pulleys 20A and 20B is increased, and the rotation angle of the main pulley 14 is increased to the first, The rotation angles of the second auxiliary pulleys 20A and 20B can be linked more accurately.

  6 to 8 show a fourth embodiment of the present invention. FIG. 6 is an overall plan view of the rotation angle detecting device, FIG. 7 is a sectional view taken along line 7-7 in FIG. 6, and FIG. FIG.

  The first and second rotation angles are formed on the upper surfaces of the other ends of the first and second swing arms 34A and 34B supported on the first and second support shafts 33A and 33B so as to swing freely. Sensors 18A and 18B are supported, and first and second auxiliary pulleys 20A and 20B are respectively provided on first and second rotation shafts 19A and 19B protruding downward from the first and second rotation angle sensors 18A and 18B. Provided. A tensioner 22 that urges the first and second swing arms 34A and 34B in a direction away from each other and applies tension to the cog belt 21 is provided with connecting portions 34a and 34a provided at the other ends of the swing arms 33 and 33. An arc-shaped plate spring 35, a guide block 36 fixed to the substrate 12, a guide rod 37 slidably supported by the guide block 36 and connected to the center of the plate spring 35, and a guide rod 37 And a coil spring 38 that urges the leaf spring 35 toward the leaf spring 35.

  When the central portion of the leaf spring 35 is pushed by the elastic force of the coil spring 38, the first and second swinging arms 34A and 34B move in a direction away from each other, and the first and second sub pulleys 20A. , 20B are pressed against the inner peripheral surface of the cog belt 21, and tension is applied to the cog belt 21. According to this embodiment, it is possible to urge both the first and second auxiliary pulleys 20 </ b> A and 20 </ b> B with a single tensioner 22 to reliably apply tension to the cog belt 21.

  Although the embodiments of the present invention have been described above, various design changes can be made without departing from the scope of the present invention.

  For example, the rotation angle detection device 11 of the present invention can be applied to detection of the rotation angle of any shaft other than the steering shaft 15.

  Further, the rotation angle detection device 11 of the embodiment includes the two auxiliary pulleys 20A and 20B, but the number of auxiliary pulleys may be three or more.

Overall plan view of the rotation angle detecting apparatus according to the first embodiment. 2-2 sectional view of FIG. 3-3 sectional view of FIG. Overall plan view of rotation angle detection apparatus according to second embodiment Overall plan view of the rotation angle detecting device according to the third embodiment. Overall Plan View of Rotation Angle Detection Device According to Fourth Embodiment Sectional view along line 7-7 in FIG. Sectional view taken along line 8-8 in FIG.

Explanation of symbols

14 Main pulley (Main ring)
15 Steering shaft (shaft)
18A First rotation angle sensor (rotation angle sensor)
18B Second rotation angle sensor (rotation angle sensor)
19A 1st rotating shaft 19B 2nd rotating shaft 20A 1st sub pulley (sub ring)
20B 2nd sub pulley (sub ring)
21 Cog belt (endless belt)
22 Tensioner 34A First swing arm (first support)
34B Second swing arm (second support)
35 leaf spring

Claims (5)

A main ring (14) provided on the outer periphery of the rotating shaft (15);
A plurality of secondary rings (20A, 20B) that rotate in conjunction with the rotation of the main ring (14);
A plurality of rotation angle sensors (18A, 18B) that respectively detect the rotation angles of the plurality of sub-annular rings (20A, 20B);
A rotation angle detecting device for detecting a rotation angle of the shaft (15) based on outputs of the plurality of rotation angle sensors (18A, 18B),
An endless belt (21) is wound around the main ring (14) and the plurality of sub rings (20A, 20B), and the plurality of sub rings (20A, 20A, 20B) are interlocked with the rotation of the main ring (14). 20B), and a tensioner (22) applies tension to the endless belt (21).   The rotation angle detecting device according to claim 1, wherein the tensioner (22) biases the endless belt (21) from the inner peripheral side to the outer peripheral side to apply tension.   The rotation angle detecting device according to claim 1, wherein the tensioner (22) biases the endless belt (21) from the outer peripheral side to the inner peripheral side to apply tension. A first support (34A) that supports the first rotating shaft (19A) of the first sub-annular (20A) and a second support that supports the second rotating shaft (19B) of the second sub-annular (20B). (34B) is supported so as to be movable toward and away from each other,
The tensioner (22) includes an elastic body (35) that urges the first and second support bodies (34A, 34B) in directions away from each other and applies tension to the endless belt (21). The rotation angle detection device according to claim 1, wherein:   The endless belt (21) is a cog belt that engages with the main ring (14) and the sub ring (20A, 20B) in a concave-convex manner. The rotation angle detection device described in 1.

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