JP5574862B2 - Rotation angle detector - Google Patents

Description

  The present invention relates to a rotation angle detection device mainly used for detecting a rotation angle of a steering wheel of an automobile.

In recent years, as the functions of automobiles have advanced, the number of steering angle detection devices that use various rotation angle detection devices to control various types of vehicles using this has increased.
Such a conventional rotation angle detection device will be described with reference to FIGS.

  FIG. 7 is a cross-sectional view of a conventional rotation angle detection device, and FIG. 8 is an exploded perspective view thereof. In FIG. 7, a spur gear is formed on the outer periphery of the side surface of the case 1 made of insulating resin having mounting surface portions 1A formed on the left and right. The formed first detection gear 2 is rotatably mounted, and a part of the first detection gear 2 protrudes outward from the side surface of the case 1.

A second detection gear 3 having a spur gear having a different number of teeth from the first detection gear 2 on the outer periphery of the side surface meshes with the first detection gear 2 and is rotatably accommodated in the case 1. Has been.
A wiring board 4 having a plurality of wiring patterns (not shown) formed on both surfaces is disposed substantially in parallel above the first and second detection gears 2 and 3 and the first detection gear 2. Magnetic detecting elements 5B and 6B are mounted on the opposing surfaces of the magnet 5A mounted at the center of the magnet and the magnet 6A mounted at the center of the second detection gear 3, respectively.

  The first detection means 5 is formed by the magnet 5A and the magnetic detection element 5B opposed to each other, and the second detection means 6 is formed by the magnet 6A and the magnetic detection element 6B. The control means 7 connected to the magnetic detection elements 5B and 6B is formed by electronic components such as a microcomputer.

Furthermore, a cover 8 made of an insulating resin covers the upper surface of the case 1 in which the first and second detection gears 2 and 3 and the wiring board 4 are housed to constitute a rotation angle detection device.
In the rotation angle detecting device configured as described above, the control means 7 is connected to an electronic circuit (not shown) of the automobile via a connector, a lead wire (not shown), etc. The first detection gear 2 projecting from the gear meshes with a spur gear on the outer periphery of the side surface of the rotary gear 10 having a steering shaft (not shown) inserted and fixed at the center thereof, and is mounted on the automobile.

  At this time, as shown in the plan view of FIG. 9, the rotation center of the first detection gear 2 extends from the rotation center of the rotation gear 10 in a direction orthogonal to the attachment line TL connecting the attachment surface portions 1 </ b> A on the left and right sides of the case 1. It is arranged on the center line CL that extends.

  In the above configuration, when a steering wheel (not shown) whose central portion is connected to the steering shaft is rotated, the rotating gear 10 is rotated, and in conjunction with this, the first detection gear 2 and the second detection gear 3 are rotated. Since each of the magnets 5A and 6A rotates, the magnets 5A and 6A mounted in the center also rotate, and the magnetic detecting elements 5B and 6B detect the changing magnetic force of the magnets 5A and 6A, and are formed from predetermined data waveforms. A detection signal is input to the control means 7.

  At this time, since the first detection gear 2 and the second detection gear 3 have different numbers of teeth, the data waveforms from the magnetic detection elements 5B and 6B become detection signals having a phase difference and are controlled. Input to means 7.

  Then, the control means 7 performs a predetermined calculation from the detection signals from the first detection gear 2 and the second detection gear 3 and the number of teeth of each gear, and the rotation angle of the rotary gear 10, that is, the steering wheel. Is output to an electronic circuit of the automobile body, and various controls of the vehicle such as a power steering device and a brake device are performed.

  In addition, when the first detection gear 2 protruding from the side surface of the case 1 as described above is engaged with the rotation gear 10 and the rotation angle detection device is mounted on the vehicle, the rotation center of the first detection gear 2 is rotated. Since it is arranged on the center line CL extending in the direction orthogonal to the mounting surface portion 1A from the rotation center of the gear 10, as shown in the partial plan view of FIG. When the tooth bottom is in a position where one tooth bottom matches the other tooth tip, the gear can be meshed as it is, but as shown in FIG. 10 (b), the gear tooth tip and the tooth tip face each other. In such a state, the gears may be damaged if they are meshed as they are.

  Therefore, in such a case, the rotation angle detection device is temporarily removed, and one of the first detection gear 2 or the rotation gear 10 is slightly rotated by hand so that the tooth tips and the tooth bottoms of the respective gears are aligned. After that, it was necessary to reassemble.

  As prior art document information related to the invention of this application, for example, Patent Document 1 is known.

JP 2008-275546 A

  However, in the conventional rotation angle detection device, when the first detection gear 2 protruding from the side surface of the case 1 is meshed with the rotation gear 10, it is necessary to mesh the tooth tips of the gears with the tooth bottoms. For this reason, there is a problem that assembling takes time and takes time.

  The present invention solves such a conventional problem, and an object of the present invention is to provide a rotation angle detection device that can be easily assembled and can reliably detect the rotation angle.

In order to achieve the above-described object, the present invention is configured such that the rotation center of the detection gear meshing with the rotation gear is decentered from the center line extending from the rotation center of the rotation gear in the direction orthogonal to the attachment surface portion, and the tip end portion is located on the attachment surface portion. The rotation angle detection device is configured by providing a protrusion formed with a step so that the thin root portion is thick , and when the detection gear meshes with the rotation gear, the tooth tip of one gear and the other Even when the tooth tips are facing each other, the detection gear rotates and can be assembled with each tooth tip and the tooth bottom aligned , and the case mounting surface has a step so that the tip is thin and the root is thick. By assembling the rotation angle detection device to the vehicle by inserting the protrusion formed by attaching it to the through hole of the vehicle casing, it is possible to align the tooth tip and the tooth bottom of each gear. Rotation angle detector that can be assembled easily and without any hassle It is expected to have an effect that it is possible to obtain.

  As described above, according to the present invention, it is possible to obtain an advantageous effect that a rotation angle detection device that can be easily assembled and can reliably detect the rotation angle can be realized.

Sectional drawing of the rotation angle detection apparatus by one embodiment of this invention Exploded perspective view Plan view Partial plan view Partial plan view Plan view Sectional view of a conventional rotation angle detector Exploded perspective view Plan view Partial plan view

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
In addition, the same code | symbol is attached | subjected to the part of the structure same as the structure demonstrated in the term of background art, and detailed description is simplified.

(Embodiment)
FIG. 1 is a cross-sectional view of a rotation angle detection device according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view. In FIG. A plurality of substantially cylindrical projections 11B are provided with steps that are slightly thin and have a slightly thicker root portion.

  A first detection gear 12 made of insulating resin or non-magnetic metal and having a spur gear formed on the outer periphery of the side surface is rotatably mounted at a position slightly eccentric to the left from the center of the case 11. A part of one detection gear 12 protrudes outward from the side surface of the case 11.

  Then, the second detection gear 13 having a spur gear having a different number of teeth from the first detection gear 12 on the outer periphery of the side surface meshes with the first detection gear 12 and is rotatably accommodated in the case 11. Has been.

  In addition, a plurality of wiring patterns (not shown) are formed on both surfaces or one surface of the wiring substrate 14 disposed substantially in parallel above the first and second detection gears 12 and 13, and the first On the opposing surface of the magnet 5A attached to the center of the detection gear 12 by insert molding or the like and the magnet 6A attached to the center of the second detection gear 13, an AMR (anisotropic magnetoresistive) element or a Hall element is provided. The magnetic detection elements 5B and 6B are mounted.

  The first detection means 5 is formed by the magnet 5A and the magnetic detection element 5B opposed to each other, and the second detection means 6 is formed by the magnet 6A and the magnetic detection element 6B. The control means 7 connected to the magnetic detection elements 5B and 6B is formed by electronic components such as a microcomputer.

Furthermore, a cover 18 made of an insulating resin covers the upper surface of the case 11 in which the first and second detection gears 12 and 13 and the wiring board 14 are housed to constitute a rotation angle detection device.
In the rotation angle detecting device configured as described above, the control means 7 is connected to an electronic circuit (not shown) of the automobile via a connector, a lead wire (not shown), etc. The first detection gear 12 projecting from the gear is fitted to the automobile in mesh with a spur gear on the outer periphery of the side surface of the rotary gear 10 with a steering shaft (not shown) inserted and fixed at the center.

  At this time, since the first detection gear 12 is mounted at a position slightly decentered to the left with respect to the center of the case 11, in the state of meshing with the rotary gear 10, the plane of FIG. As shown in the figure, the rotation center of the first detection gear 12 is slightly from the center line CL extending from the rotation center of the rotation gear 10 in a direction orthogonal to the attachment line TL connecting the attachment surface portions 11A on the left and right sides of the case 11. It is arranged at a position eccentric by a dimension h to the left.

  In addition, the tooth tips of these gears are formed in a substantially arc shape, and the diameter and the number of teeth of these gears are the largest in the rotating gear 10 and become smaller in the order of the first detection gear 12 and the second detection gear 13. For example, the rotation gear 10 has 48 teeth, the first detection gear 12 has 32 teeth, and the second detection gear 13 has 18 teeth.

  In the above configuration, when a steering wheel (not shown) whose central portion is coupled to the steering shaft is rotated, the rotating gear 10 is rotated, and in conjunction with this, the first detecting gear 12 and the second detecting gear 13 are rotated. Since each of the magnets 5A and 6A rotates, the magnets 5A and 6A mounted in the center also rotate, and the magnetic detecting elements 5B and 6B detect the changing magnetic force of the magnets 5A and 6A, and are formed from predetermined data waveforms. A detection signal is input to the control means 7.

  At this time, since the first detection gear 12 and the second detection gear 13 have different numbers of teeth, the data waveforms from the magnetic detection elements 5B and 6B become detection signals having a phase difference and are controlled. Input to means 7.

  Then, the control means 7 performs a predetermined calculation from the detection signals from the first detection gear 12 and the second detection gear 13 and the number of teeth of each gear, and the rotation angle of the rotary gear 10, that is, the steering wheel. Is output to an electronic circuit of the automobile body, and various controls of the vehicle such as a power steering device and a brake device are performed.

  Further, in the present invention, when the first detection gear 12 protruding from the side surface of the case 11 is engaged with the rotation gear 10 and the rotation angle detection device is mounted on the vehicle, the partial plan view of FIG. As shown in FIG. 4 (b), even when the tooth tip of one gear is in a position where the tooth root of the other gear and the tooth bottom of the other gear are in contact with the other tooth tip, Even when the tooth tip and the other tooth tip face each other, the meshing can be performed as it is.

  That is, the rotation center of the first detection gear 12 is attached to the case 11 by being eccentric from the center line CL extending from the rotation center of the rotation gear 10 in the direction orthogonal to the mounting surface portion 11A to the left by the dimension h. Therefore, as shown in FIG. 4B, even when the tooth tip of one gear and the other tooth tip face each other, if the case 11 is pressed in the direction of the rotating gear 10 as it is, the rotating gear The first detection gear 12 is rotated by applying an oblique force eccentric from the center line CL to the tooth tip of the first detection gear 12 in contact with the ten tooth tips, and the tooth tip and the tooth bottom of each other rotate. Engagement with the rotating gear 10 is performed in the combined state.

  Therefore, even if the tooth tip of the first detection gear 12 and the tooth tip of the rotation gear 10 are opposed to each other, the rotation angle detection device is once removed and one of the first detection gear 12 or the rotation gear 10 is manually held. There is no need to rotate slightly and align the tooth tips and tooth bottoms of the gears, and it is easy and easy to assemble.

  In addition, when such a rotation angle detection device is assembled into a vehicle, an excessive force is not applied to the first detection gear 12 or the rotation gear 10 and the gears are not damaged. Thus, rotation is performed, and the rotation angle can be detected without error.

  Further, as shown in the partial plan view of FIG. 5B, the protrusions 11B of the left and right attachment surface portions 11A of the case 11 are inserted into the through holes 20A of the vehicle-side casing 20, and the rotation angle to the vehicle is detected. At this time, the protrusion 11B has a slightly narrow tip, a slightly thick base, and a step, so that the tooth tip and the tooth tip of the opposite gear are connected to the tooth tip. It is also possible to adjust the state where the roots are aligned.

  That is, as shown in FIG. 4B, the tooth tip of the first detection gear 12 and the tooth tip of the rotating gear 10 face each other, and a slightly narrow tip portion of the projection 11B is inserted into the through hole 20A. First, as shown in the partial plan view of FIG. 5A, the case 11 is moved to the left until the left end of the tip of the projection 11B comes into contact with the left end of the through hole 20A. Make sure that the bottom is generally aligned.

  After that, as shown in FIG. 5 (b), the case 11 is pressed in the direction of the rotating gear 10 and inserted into the through-hole 20A through the base part thicker than the tip part of the protruding part 11B. The first detection gear 12 can be meshed with the rotating gear 10 in a state where the tooth tip and the tooth bottom are aligned.

  At this time, since the tooth tips of the rotary gear 10 and the first detection gear 12 are formed in a substantially arc shape, the gear teeth of each gear can be shifted slightly as described above. It is possible to more easily perform meshing in a state where the tooth tip and the tooth bottom are aligned.

  In the above description, the configuration in which the two mounting surface portions 11A on the left and right sides of the case 11 are provided substantially symmetrically with respect to the center of the case 11 has been described. As shown in the plan view of FIG. 6A, the structure in which the two attachment surface portions 11A are formed at positions shifted toward the rotating gear 10, and further, as shown in FIG. The present invention can be implemented even with a single configuration.

  As described above, according to the present embodiment, the rotation center of the first detection gear 12 meshing with the rotation gear 10 is decentered from the center line CL extending from the rotation center of the rotation gear 10 in the direction orthogonal to the mounting surface portion 11A. Thus, when the first detection gear 12 is meshed with the rotary gear 10, the first detection gear 12 rotates even when the tooth tip of one gear faces the other tooth tip. Therefore, it is possible to obtain a rotation angle detecting device that can be easily assembled without taking time and effort.

  Further, the protrusion 11B of the case 11 inserted into the through hole 20A of the vehicle casing 20 is formed with a step so that the tip is slightly thin and the root is slightly thick. Also, the tooth tip and the tooth bottom of each gear can be aligned.

  In the above description, the configuration in which the control means 7 is provided together with the magnetic detection elements 5B and 6B on the wiring board 14 has been described. However, the control means 7 is provided integrally with the electronic circuit of the vehicle, and the magnetic detection element 5B is provided therewith. It is possible to implement the present invention even if the rotation angle of the rotary gear 10 is detected by connecting the 6B or 6B.

  The rotation angle detection device according to the present invention can be easily assembled and can reliably detect the rotation angle, and is mainly useful for detecting the rotation angle of the steering of an automobile.

5 First detection means 6 Second detection means 5A, 6A Magnets 5B, 6B Magnetic detection element 7 Control means 10 Rotating gear 11 Case 11A Mounting surface portion 11B Projection portion 12 First detection gear 13 Second detection gear 14 Wiring Board 18 Cover 20 Housing 20A Through-hole

Claims (1)

A case in which a mounting surface portion is formed;
A detection gear rotatably mounted on the case and meshing with the rotation gear;
Detection means for detecting the rotation of the detection gear;
It comprises control means for detecting the rotation angle of the rotating gear based on a detection signal from the detection means,
The rotation center of the detection gear is eccentrically provided from a center line extending in a direction orthogonal to the mounting surface portion from the rotation center of the rotation gear ,
The rotation angle detecting device, wherein the mounting surface portion is provided with a protrusion formed with a step so that the tip portion is thin and the root portion is thick .

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