JP2019105529A - Rotary encoder - Google Patents

Abstract

To provide a rotary encoder which can be easily attached to and detached from a rotary body, has excellent versatility, and can reduce an installation space.SOLUTION: A rotary encoder 1A includes: a rotor 3 having a bolt cover 6 which is fitted by a bolt fitting hole 5 to a head 2a of a hexagonal bolt 2 coaxially mounted on a crankshaft 110 and can be rotated coaxially with the hexagonal bolt 2 and a detection magnet 8 provided on the bolt cover 6; and a detection element 4 provided independently of the rotor 3 and detecting a displacement of the detection magnet 8.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotary encoder.

  As a rotation detector for detecting rotation of a crankshaft of an engine, there is one configured to connect a rotation shaft to the crankshaft via a gear mechanism and to detect rotation of the rotation shaft by a detection element. (See, for example, Patent Document 1).

JP, 2015-165189, A

In the above-described conventional rotation detector, since the gear mechanism is incorporated in the engine, attachment and detachment to the engine becomes complicated, and it is necessary to prepare the gear mechanism for each type of engine, and the cost for detecting rotation is high. Problem of becoming
Further, in the conventional rotation detector, the number of parts increases and the size of the device increases, which makes it difficult to secure an installation space in the engine room.

  An object of the present invention is to solve the above-mentioned problems, and to provide a rotary encoder which can be easily attached to and detached from a rotating body, has excellent versatility, and can reduce the installation space.

  In order to solve the above problems, according to the present invention, a bolt cover is fitted to a head of a bolt coaxially attached to a rotating body by a bolt fitting hole and provided coaxially with the bolt, and the bolt cover A rotary encoder including: a rotor having the detection magnet; and a detection element provided independently of the rotor and detecting a displacement of the detection magnet.

  According to the present invention, the rotor can be configured with a simple structure in which the bolt cover is fitted to the head of the bolt, and the rotor can be easily attached to and detached from the rotating body. Since a standard bolt can be used, the structure has excellent versatility. The rotary encoder can be miniaturized and the installation space can be reduced by providing the detection element independently from the rotor without providing the connection element for positioning the detection element and the rotor relative to each other. There is also no need for bearings for supporting the rotor, and the product cost can be reduced. Since it is not necessary to form a bearing fitting on the bolt cover, the length dimension of the bolt cover can be reduced.

  Further, the present invention is characterized in that the rotor has a bolt attracting magnet which is fixed to the bolt cover by press-fitting or adhesive and adsorbs the head of the bolt to position the bolt cover. Do.

  According to the present invention, the bolt cover can be securely fixed to the bolt by the bolt attracting magnet. By fixing the bolt suction magnet to the bolt cover by press-fitting or using an adhesive, it is possible to suppress the enlargement of the bolt cover and to improve the assembling workability without separately providing a fixing screw or the like.

  Further, the present invention is characterized in that the bolt attracting magnet comprises a magnet body and a yoke for closing a magnetic circuit between the magnet body and the bolt.

  According to the present invention, by providing the yoke, the attraction force of the bolt attraction magnet can be enhanced as the yoke-equipped magnet set.

  Further, the present invention is characterized in that the bolt is a hexagonal socket bolt, and the yoke abuts on a bottom surface of the hexagonal hole.

  According to the present invention, the bolt attracting magnet attracts the head of the hexagonal socket bolt with the hexagonal socket. Positioning the bolt cover in the axial direction can be easily performed by bringing the yoke into contact with the bottom of the hexagonal hole.

  Further, the present invention is characterized in that the bolt is a hexagonal socket bolt, and the yoke abuts around an edge of the hexagonal hole.

  According to the present invention, the bolt attracting magnet attracts the head of the hexagonal socket bolt around the edge of the hexagonal socket. Abutment of the yoke around the edge of the hexagonal hole facilitates axial positioning of the bolt cover.

  Further, according to the present invention, the bolt is a hexagonal bolt, and the bolt fitting hole is provided with a polygonal portion which is engaged with the side portion of the head of the hexagonal bolt.

  According to the present invention, the bolt cover can be rotated integrally with the hexagonal bolt by locking the head of the hexagonal bolt and the polygonal portion of the bolt fitting hole. By making the polygonal part into a socket hole shape for tools such as 12 square contact, 6 hexagonal contact, 12 square contact, etc., machining of the bolt fitting hole becomes easy, and the fitting and assembling property of the hexagonal bolt is also good. become.

  Further, the present invention is characterized in that the detection magnet positions the bolt cover by adsorbing the head of the bolt.

  According to the present invention, the detection magnet doubles as a detected function whose rotational displacement is detected by the detection element, and a bolt suction function of suctioning the head of the bolt to position the bolt cover. As a result, it is possible to suppress the increase in the number of parts and to improve the assembling workability.

  Further, the present invention is characterized in that the bolt cover is fixed to the bolt by pressing the head of the bolt into the bolt fitting hole.

  According to the present invention, when assembling a bolt cover to a bolt as a one-piece rotary structure, only a simple press-fitting operation can be performed without requiring a fixing screw and the like.

  Further, the present invention is characterized in that the detection magnet and the detection element are disposed opposite to each other on the rotation axis of the rotor.

  ADVANTAGE OF THE INVENTION According to this invention, when it is difficult to ensure the arrangement | positioning space of a detection element on the outer side of the outer peripheral surface of a bolt cover, it can respond easily.

  Further, the present invention is characterized in that the detection magnet and the detection element are disposed to face each other on the outer side of the outer peripheral surface of the bolt cover.

  According to the present invention, it is possible to easily cope with the case where it is difficult to secure the arrangement space of the detection element outside the end of the bolt cover.

  According to the present invention, the rotary encoder can be miniaturized and the installation space can be reduced by providing the detection element independently from the rotor without providing the connection element for positioning the detection element and the rotor relative to each other. .

1 is a side sectional view of a rotary encoder according to a first embodiment of the present invention. It is a perspective view of a bolt cover concerning a 1st embodiment of the present invention. It is a front view of the bolt cover which made the bolt fitting hole the socket hole shape for tools of angular contact hexagon. It is a front view of the bolt cover which made the bolt fitting hole the socket hole shape for tools of angular contact 12 angles. It is a sectional side view of the rotary encoder concerning a 2nd embodiment of the present invention. It is a sectional side view of the rotary encoder concerning a 3rd embodiment of the present invention. It is a sectional side view of the rotary encoder concerning a 4th embodiment of the present invention. It is a sectional side view of the rotary encoder concerning a 5th embodiment of the present invention. It is a sectional side view of the rotary encoder concerning a 6th embodiment of the present invention. It is a sectional side view of the rotary encoder concerning a 7th embodiment of the present invention. It is a sectional side view of the rotary encoder which concerns on 8th Embodiment of this invention.

  Several embodiments of the present invention will be described. In the description of each embodiment, the same components will be denoted by the same reference symbols and redundant description will be omitted.

First Embodiment
In FIG. 1, a rotary encoder 1A according to the first embodiment detects a rotational displacement of a crankshaft 110 of an engine as an example of a rotating body. A crank pulley 120 is fastened to an end face of the crankshaft 110 by a hexagonal bolt 2 screwed on an axial center O of the crankshaft 110. Thereby, the crank pulley 120 and the hexagonal bolt 2 rotate around the axis O integrally with the crankshaft 110. The hexagonal bolt 2 is a standard product made of iron, and a hexagonal head 2a is formed at one end of the shaft portion 2b.

  The rotary encoder 1 </ b> A is configured to include a rotor 3 and a detection element 4. The rotor 3 is fitted to the head 2 a of the hexagonal bolt 2 by the bolt fitting hole 5 and rotates around an axis O coaxial with the hexagonal bolt 2, a bolt attracting magnet 7, a detection magnet And 8 are configured.

  The bolt cover 6 is a member having a cylindrical shape, and a bolt fitting hole 5 whose center of axis O is a hole center is formed at one end. The bolt cover 6 is formed of nonmagnetic material such as nonmagnetic stainless steel, aluminum, brass, copper, synthetic resin, synthetic rubber and the like. The inner peripheral surface of the bolt fitting hole 5 is provided with a polygonal portion which is engaged with the side portion of the head 2 a of the hexagonal bolt 2 so that the bolt cover 6 and the hexagonal bolt 2 integrally rotate. As an example of shape, as shown in FIG. 2, the inner peripheral surface of the bolt fitting hole 5 is made into a so-called socket hole shape for a surface contact (wave) 12 corner that contacts the side surface of the head 2a. In addition, it may be configured as a six-sided angular contact shown in FIG. 3 or a socket hole shape for a tool with twelve angular contact shown in FIG. In FIG. 1, a magnet receiving hole 9 for receiving the bolt attracting magnet 7 is formed on the bottom of the bolt fitting hole 5 with the axis O at the center.

  The bolt suction magnet 7 sucks the head 2 a of the hexagonal bolt 2 to position the bolt cover 6 with respect to the hexagonal bolt 2. The bolt attracting magnet 7 is configured to include a magnet body 10 and a yoke 11 for closing a magnetic circuit between the magnet body 10 and the hexagonal bolt 2. The magnet body 10 has a disk shape that is disposed about the axial center O, and is disposed such that the boundary surface of the NS pole is orthogonal to the axial center O. The yoke 11 is a bottomed flat cylindrical case member for housing the magnet main body 10, and is made of a magnetic material such as iron. The magnet body 10 is fixed in the yoke 11 via an adhesive or the like. The yoke 11 is housed and fixed in the magnet housing hole 9 by press-fitting or an adhesive so that the bottom portion thereof is in contact with the bottom surface of the magnet housing hole 9.

  The detection magnet 8 has a disk shape disposed around the axial center O, and the S pole and the N pole are disposed adjacent to each other around the axial center O. The detection magnet 8 is accommodated by an adhesive or the like in a recess formed around the axis O at the other end face of the bolt cover 6.

  The detection element 4 is a magnetic detection element that detects rotational displacement of the detection magnet 8. That is, the detection element 4 detects a change in the magnetic field of the detection magnet 8 which rotates around the axis O. Thus, the rotary encoder 1A detects the rotational displacement of the crankshaft 110. The detection element 4 is disposed on the axial center O so as to face the detection magnet 8. The sensing element 4 is attached to a substrate 12 disposed along a plane orthogonal to the axis O.

  The sensing element 4 is provided independently of the rotor 3. In the present invention, “independently of the rotor 3” means that there is no connecting element for connecting the sensing element 4 and the rotor 3 and positioning the both relative to each other. For example, as an example in which the connection element is provided, there is provided a case in which the substrate 12 is fixed and accommodated, and a case in which the outer periphery of the bolt cover 6 is rotatably supported via a bearing or the like. However, in this structure, the entire size of the rotary encoder 1A is increased by the presence of the case, and there is a possibility that it can not cope with a narrow installation space. Moreover, the bearing which pivotally supports the rotor 3 is also needed, and the increase in a product cost is caused.

  On the other hand, there is no connection element for positioning the detection element 4 and the rotor 3 relative to each other, and by providing the detection element 4 independently from the rotor 3, the connection element does not exist. Miniaturization can be achieved, and the installation space can be reduced. Therefore, the rotary encoder 1A can be easily attached to the crankshaft 110 in a narrow space or the like in the engine room of the vehicle. As no bearing is required to support the rotor 3, the product cost can be reduced. In particular, since it is not necessary to form the fitting portion of the bearing in the bolt cover 6, the length dimension in the direction of the axis O of the bolt cover 6 can be suppressed. Also in the second to eighth embodiments to be described later, the sensing element 4 is provided independently of the rotor 3, and the same effect as that of the first embodiment can be obtained.

  In the rotary encoder 1A of the first embodiment, the rotor 3 can be configured with a simple structure in which the bolt cover 6 is fitted to the head 2a of the hexagonal bolt 2. Since the bolt cover 6 is fitted to the head 2 a of the standardized hexagonal bolt 2, versatility can be enhanced. As a result, there is no need to provide a mounting mechanism designed for each engine model between the crankshaft 110 and the rotary encoder 1A, so the cost for detecting the rotation of the crankshaft 110 can be reduced.

  In the rotary encoder 1A of the first embodiment, the rotor 3 has a bolt attracting magnet 7 for attracting the head 2a of the hexagonal bolt 2 to position the bolt cover 6. Thus, the bolt cover 6 can be securely fixed to the hexagonal bolt 2. By fixing the bolt suction magnet 7 to the bolt cover 6 by press-fitting or using an adhesive, it is possible to suppress the enlargement of the bolt cover 6 and to improve the assembling workability without separately providing a fixing screw or the like.

  In the rotary encoder 1A of the first embodiment, the bolt attraction magnet 7 includes the magnet body 10 and the yoke 11 closing the magnetic circuit between the magnet body 10 and the bolt 2. By providing the yoke 11, the attraction force of the bolt attraction magnet 7 can be enhanced as a yoke-attached magnet set.

  If the detection magnet 8 and the detection element 4 are arranged to face each other on the axis O, it is easy to secure a space for arranging the detection element 4 outside the outer peripheral surface of the bolt cover 6. It can correspond.

  If the bolt cover 6 is fixed to the hexagonal bolt 2 by pressing the head 2 a of the hexagonal bolt 2 into the bolt fitting hole 5, the assemblability of the rotor 3 to the hexagonal bolt 2 is improved. Do. Also, depending on the case, an adhesive may be interposed between the head 2 a of the hexagonal bolt 2 and the bolt fitting hole 5.

"2nd Embodiment"
In the rotary encoder 1A of the first embodiment, the detection magnet 8 and the detection element 4 are disposed opposite to each other on the axis O, but as shown in FIG. 5, the rotary encoder 1B of the second embodiment The detection magnet 8A and the detection element 4 are disposed to face each other on the outer side of the outer peripheral surface of the bolt cover 6. The detection magnet 8A is a ring-shaped magnet disposed so that the S pole and the N pole are adjacent to each other around the axis O, and is fitted and fixed to the outer peripheral surface of the bolt cover 6 with an adhesive or the like. The detection element 4 is disposed to face the outer peripheral surface of the detection magnet 8A.

  When the detection magnet 8A and the detection element 4 are arranged to face each other outside the outer peripheral surface of the bolt cover 6, it is difficult to secure the arrangement space of the detection element 4 outside the end of the bolt cover 6 Can easily cope with

"3rd Embodiment"
The rotary encoder 1C according to the third embodiment, as shown in FIG. 6, includes a bolt cover 6 that rotates integrally with the hexagonal socket bolt 21. The hexagonal socket bolt 21 is a standard product made of iron, and a circular head 21a is formed at one end of the shaft 21b. A hexagonal hexagonal hole 21c is formed on the end face of the head 21a.

  At one end of the bolt cover 6, a circular bolt fitting hole 5 is formed which follows the outer peripheral surface of the head 21a. On the bottom surface of the bolt fitting hole 5, a hexagonal shaft portion 13 fitted to the hexagonal hole 21c is provided in a protruding manner. By fitting the hexagonal hole 21 c and the hexagonal shaft portion 13, the hexagonal holed bolt 21 and the bolt cover 6 integrally rotate. The length in the axial center O direction of the hexagonal shaft portion 13 is substantially the same as the depth of the hexagonal hole 21 c.

  A magnet housing hole 9 for housing the bolt suction magnet 7 is formed on the tip end face of the hexagonal shaft portion 13. The bolt attracting magnet 7 is configured to include the magnet body 10 and the yoke 11. Although the size is different, as in the first and second embodiments, the magnet body 10 has a disk shape disposed around the axial center O, and the boundary surface of the NS pole is orthogonal to the axial center O It is arranged to be. The yoke 11 has a bottomed cylindrical shape. The magnet body 10 is fixed in the yoke 11 via an adhesive or the like. The yoke 11 is housed and fixed in the magnet housing hole 9 by press-fitting or an adhesive so that the bottom portion thereof is in contact with the bottom surface of the magnet housing hole 9. The tip end edge of the yoke 11 is in contact with the bottom surface of the hexagonal hole 21c.

  As described above, since the head 21 a of the hexagonal socket bolt 21 is attracted to the bolt suction magnet 7 of the hexagonal shaft part 13, the bolt cover 6 can be securely fixed to the hexagonal socket bolt 21. By bringing the yoke 11 into contact with the bottom of the hexagonal hole 21c, positioning of the bolt cover 6 in the direction of the axis O can be easily performed.

"4th Embodiment"
In the rotary encoder 1C of the third embodiment, the detection magnet 8 and the detection element 4 are disposed to face each other on the axial center O, but as shown in FIG. 7, the rotary encoder 1D of the fourth embodiment The detection magnet 8A and the detection element 4 are disposed to face each other on the outer side of the outer peripheral surface of the bolt cover 6.

  When the detection magnet 8A and the detection element 4 are arranged to face each other outside the outer peripheral surface of the bolt cover 6, it is difficult to secure the arrangement space of the detection element 4 outside the end of the bolt cover 6 Can easily cope with

"Fifth embodiment"
In the rotary encoder 1C of the third embodiment, the yoke 11 is in contact with the bottom surface of the hexagonal hole 21c, but as shown in FIG. 8, in the rotary encoder 1E of the fifth embodiment, the yoke 11 is in the hexagonal hole 21c. It is different in that it abuts around the edge 21d of the.

  At one end of the bolt cover 6, a circular bolt fitting hole 5 is formed which follows the outer peripheral surface of the head 21a. The depth of the bolt fitting hole 5 is larger than the height of the head 21 a of the hexagonal socket bolt 21. On the bottom surface of the bolt fitting hole 5, a hexagonal shaft portion 13 fitted to the hexagonal hole 21c is provided in a protruding manner. By fitting the hexagonal hole 21 c and the hexagonal shaft portion 13, the hexagonal holed bolt 21 and the bolt cover 6 integrally rotate.

  An annular space around the axis O is formed between the edge 21 d of the hexagonal hole 21 c and the bottom of the bolt fitting hole 5, and the bolt attracting magnet 7 is accommodated in the annular space. That is, the periphery of the bottom surface of the bolt fitting hole 5 constitutes the magnet accommodation hole 9. The bolt attraction magnet 7 is configured to include a ring-shaped magnet main body 10 and a yoke 11 in which holes for passing the hexagonal shaft portions 13 are formed. The magnet body 10 is fixed in the yoke 11 via an adhesive or the like. The yoke 11 is housed and fixed such that the bottom portion thereof is in contact with the bottom surface of the bolt fitting hole 5 by press-fitting or an adhesive. The front end edge of the yoke 11 abuts around the edge 21 d of the hexagonal hole 21 c.

  As described above, since the head 21 a of the hexagonal socket bolt 21 is attracted to the bolt suction magnet 7 of the hexagonal shaft part 13, the bolt cover 6 can be securely fixed to the hexagonal socket bolt 21. Positioning the bolt cover 6 in the axial center O direction can be easily performed by bringing the yoke 11 into contact with the periphery 21 d of the hexagonal hole 21 c.

"Sixth embodiment"
A rotary encoder 1F of the sixth embodiment shown in FIG. 9 is different from the rotary encoder 1E of the fifth embodiment in the shape of the yoke 11. In FIG. 9, the yoke 11 of the rotary encoder 1F of the sixth embodiment is formed with an inner side wall portion 14 rising from the edge of the hole through which the hexagonal shaft portion 13 passes to the edge 21d of the hexagonal hole 21c. The magnet body 10 is accommodated between the outer wall of the yoke 11 and the inner wall 14. The leading edge of the outer wall of the yoke 11 and the leading edge of the inner wall 14 abut on the edge 21 d of the hexagonal hole 21 c.

  According to the rotary encoder 1F of the sixth embodiment, the magnetic circuit between the magnet main body 10 and the hexagonal socket bolt 21 can be effectively closed by the inner side wall portion 14, and the attraction force of the bolt attraction magnet 7 Improve.

"Seventh embodiment"
In the rotary encoder 1G of the seventh embodiment shown in FIG. 10, the detection magnet 8B has a detected function whose rotational displacement is detected by the detection element 4, and the head 2a of the hexagonal bolt 2 by adsorbing the bolt cover 6 It doubles as a bolt suction function to position. The detection magnet 8B has a disk shape that is disposed around the axial center O. The detection magnet 8B is disposed such that an S pole and an N pole are adjacent to each other around the axis O on one side with the surface orthogonal to the axis O as a boundary, and an S pole and N on one side on the other side. The N pole and the S pole are disposed adjacent to the pole.

  The bolt cover 6 is formed with a bolt fitting hole 5 and a magnet housing hole 15 having a diameter smaller than that of the bolt fitting hole 5 and penetrating from the bottom of the bolt fitting hole 5 to the other end of the bolt cover 6 . The detection magnet 8B is fitted into the magnet housing hole 15 by press-fitting, an adhesive or the like, and one end thereof abuts on the end face of the head 2a of the hexagonal bolt 2 or opposes with a slight gap. The detection element 4 is disposed on the axial center O so as to face the detection magnet 8B.

  According to the rotary encoder 1G of the seventh embodiment, the detection magnet 8B positions the bolt cover 6 by adsorbing the detected function whose rotational displacement is detected by the detection element 4 and the head 2a of the hexagonal bolt 2 It doubles as a bolt suction function. As a result, it is possible to suppress the increase in the number of parts and to improve the assembling workability.

"8th Embodiment"
A rotary encoder 1H of the eighth embodiment shown in FIG. 11 is different from that of the seventh embodiment in that the hexagonal bolt 2 is a bolt 21 with a hexagonal hole. The rotary encoder 1 H has a detection function in which the detection magnet 8 B detects rotational displacement by the detection element 4, and a bolt suction function in which the head 21 a of the hexagonal socket bolt 21 is adsorbed to position the bolt cover 6. Also serves as. A bolt fitting hole 5 is formed through the bolt cover 6 with a constant diameter, and the head 21a is fitted to one end of the bolt fitting hole 5 by press fitting or an adhesive, and detection is performed on the other end. The magnet 8B is fitted by press fitting, an adhesive or the like. One end side of the detection magnet 8B abuts on the edge 21d of the hexagonal socket bolt 21 or opposes with a slight gap. The detection element 4 is disposed on the axial center O so as to face the detection magnet 8B.

  Also by the rotary encoder 1H of the eighth embodiment, the detection magnet 8B positions the bolt cover 6 by adsorbing the detected function whose rotational displacement is detected by the detection element 4 and the head 21a of the hexagonal socket bolt 21 Double as a bolt suction function. As a result, it is possible to suppress the increase in the number of parts and to improve the assembling workability.

1A to 1H Rotary encoder 2 Hexagon bolt 2a Head 3 Rotor 4 Detection element 5 Bolt fitting hole 6 Bolt cover 7 Bolt adsorption magnet 8 Detection magnet 9 Magnet accommodation hole 10 Magnet body 11 Yoke 21 Hexagon socket bolt 21a Head Part 21c Hexagon Socket 21d Edge

Claims (10)

A rotor having a bolt cover fitted with a bolt fitting hole in a head of a bolt coaxially attached to a rotating body and rotated coaxially with the bolt, and a detection magnet provided on the bolt cover ,
A detection element provided independently of the rotor and detecting a displacement of the detection magnet;
A rotary encoder comprising: The rotor is
The rotary encoder according to claim 1, further comprising a bolt suction magnet fixed to the bolt cover by press-fitting or an adhesive and suctioning the head of the bolt to position the bolt cover. The bolt attracting magnet is
Magnet body,
A yoke closing a magnetic circuit between the magnet body and the bolt;
The rotary encoder according to claim 2, further comprising: The bolt is a hexagonal socket bolt,
The rotary encoder according to claim 3, wherein the yoke abuts on a bottom surface of the hexagonal hole. The bolt is a hexagonal socket bolt,
The rotary encoder according to claim 3, wherein the yoke abuts around an edge of the hexagonal hole. The bolt is a hexagonal bolt,
The rotary encoder according to any one of claims 1 to 3, wherein the bolt fitting hole includes a polygonal portion that locks to a side portion of a head of the hexagonal bolt.   The rotary encoder according to claim 1, wherein the detection magnet positions the bolt cover by attracting the head of the bolt.   The rotary according to any one of claims 1 to 7, wherein the bolt cover is fixed to the bolt by pressing the head of the bolt into the bolt fitting hole. Encoder.   The rotary encoder according to any one of claims 1 to 8, wherein the detection magnet and the detection element are disposed to face each other on the rotation axis of the rotor.   The rotary encoder according to any one of claims 1 to 8, wherein the detection magnet and the detection element are disposed to face each other on the outer side of the outer peripheral surface of the bolt cover.

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