JP2011117759A - Encoder, motor device and mounting method for the encoder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce fluctuation of detection accuracy among individual encoders. <P>SOLUTION: An encoder includes a rotating section having a pattern and fixed on a rotating axis member of an object to be measured, a body section having a detection section for detecting the pattern and fixed on a non-rotating section of the object to be measured, and a plurality of latching sections disposed on the body section for positioning the body part, by latching to the non-rotating section. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an encoder, a motor device, and an encoder mounting method.

  An encoder is known as a device that detects rotational information such as the rotational speed, rotational angle, and rotational position of a rotating body including a rotational shaft of a motor (Patent Document 1). The encoder is used by being attached to a rotating shaft of a motor, for example. As a specific configuration of the encoder, for example, a rotating part on which a predetermined light reflection pattern and a magnetic pattern are formed is rotated integrally with a rotation shaft, and the reflected light is read by irradiating light on the light reflection pattern, for example, By detecting the change of the pattern, the rotation information of the rotating shaft of the motor can be detected.

  In the encoder having the above-described configuration, the rotating unit and a main body unit including a detection unit that detects a change in reflected light or a magnetic pattern, for example, are formed separately. For this reason, when attaching an encoder to the rotating shaft of a motor, etc., a rotation part and a main-body part are attached separately. In this case, for example, if there is a deviation in the mounting position, the detection accuracy may decrease. Therefore, for example, after each unit is mounted between the rotating unit and the detection unit so as to obtain a predetermined detection accuracy. The position is adjusted.

JP 2004-20548 A

  However, since the position adjustment between the rotating unit and the detecting unit described above may depend on the skill of the operator, there is a possibility that detection accuracy may vary between the individual encoders.

  In view of the circumstances as described above, it is an object of the present invention to provide an encoder, a motor device, and an encoder mounting method that can reduce fluctuations in detection accuracy between individuals.

  According to the first aspect of the present invention, there is a rotating part that has a pattern and is fixed to the rotating shaft member to be measured, and a detecting part that detects the pattern, and is fixed to the non-rotating part of the measuring object. An encoder is provided that includes a main body portion and a plurality of locking portions that are provided on the main body portion and position the main body portion by being locked to a non-rotating portion.

  According to the second aspect of the present invention, the rotary shaft member that is rotationally driven by the drive mechanism, the support member that supports at least the rotary shaft member, the encoder of the present invention attached to the rotary shaft member and the support member, Among the encoders, there is provided a motor device in which a rotating part is fixed to a rotating shaft member and a main body part is fixed to a supporting member.

  According to the third aspect of the present invention, the first fixing step of fixing the rotating part having the pattern to the rotating shaft member to be measured, and the main body part having the detecting part for detecting the pattern as the non-rotating part of the measuring object. An encoder mounting method comprising: a second fixing step of fixing; and a positioning step of positioning the main body portion by engaging a locking portion provided in the main body portion with the rotary shaft member prior to the second fixing step. Provided.

  According to the present invention, it is possible to reduce fluctuations in detection accuracy between encoders.

Sectional drawing which shows the structure of the encoder which concerns on embodiment of this invention. FIG. 3 is a plan view showing a partial configuration of the encoder according to the present embodiment. The figure which shows the attachment process of the encoder which concerns on this embodiment. The figure which shows the attachment process of the encoder which concerns on this embodiment. The figure which shows the attachment process of the encoder which concerns on this embodiment. The figure which shows the attachment process of the encoder which concerns on this embodiment.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view showing a configuration of a motor device MTR having an encoder EC according to the present embodiment.
As shown in FIG. 1, the encoder EC is a device that detects rotational information such as the rotational speed, rotational angle, rotational position, and the like of a rotating body such as a rotational shaft 40 of a motor device MTR (measurement target). The motor device MTR includes a rotating shaft 40 that is rotationally driven by a drive mechanism 43, a housing 41 that serves as a non-rotating portion that supports the rotating shaft 40, and an encoder EC that is disposed between the housing 41 and the housing 41. And an insertion member 50.

  The encoder EC according to the present embodiment can detect the rotation information of the rotary shaft 40 by irradiating the light on the light reflection pattern to detect the reflected light and detecting the change in magnetism generated by the magnetic pattern. It has become. The encoder EC has a rotating part R and a main part D. FIG. 2 is a diagram illustrating a configuration of the rotating portion R, the main body portion D, and the motor device MTR in plan view. Hereinafter, the configuration of the encoder EC will be described with reference to FIGS. 1 and 2.

  In the following description, an XYZ orthogonal coordinate system is set, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system. Specifically, the axial direction of the rotating shaft 40 of the motor device MTR is the Z-axis direction, the predetermined direction on the plane orthogonal to the axial direction of the rotating shaft 40 is the X-axis direction, and the direction orthogonal to the X-axis direction on the plane. Is the Y-axis direction. Further, the rotation (inclination) directions around the X axis, Y axis, and Z axis are the θX, θY, and θZ directions, respectively. For example, the rotation direction of the rotation shaft 40 is the θZ direction.

  The rotating part R is fixed to the rotating shaft 40 of the motor device MTR and is a part that rotates together with the rotating shaft 40. The rotating part R includes a disk member 10 and a magnet member 20. The rotating part R is integrally fixed to the rotating shaft 40 by a fixing mechanism (not shown) such as a screw.

  The disk member 10 is a part that is directly attached to the rotary shaft 40. The disk member 10 is attached to the rotating shaft 40 so that the center when viewed in the Z direction coincides with the center of the rotating shaft 40 when viewed in the Z direction. The disk member 10 rotates in the θZ direction with the rotation of the rotating shaft 40. The disk member 10 is made of a highly rigid material such as SUS, and has excellent deformation resistance. Other materials may be used as the constituent material of the disk member 10.

  The disk member 10 has a mounting portion 11 and a pattern forming portion 12. The attachment portion 11 is provided to protrude toward the lower surface 10b side of the disk member 10, for example. The attachment portion 11 is formed with an insertion hole 11a at a central portion in plan view. The rotation shaft 40 of the motor device MTR is inserted into the insertion hole 11a. The rotating shaft 40 of the motor device MTR is fixed by the fixing mechanism (not shown) or the like while being inserted into the insertion hole 11a.

  The pattern forming part 12 is a disk-shaped part provided around the attachment part 11. A light reflection pattern 12 a is formed on the pattern forming unit 12. The light reflection pattern 12 a is formed in an annular region along the outer periphery of the disk member 10 on the upper surface 10 a of the disk member 10. The light reflection pattern 12a is formed using, for example, a light reflection member that reflects light having a predetermined wavelength.

  The magnet member 20 is a permanent magnet formed in an annular shape. The magnet member 20 is fixed to the upper surface 10a of the disk member 10 via, for example, an adhesive (not shown). The center position of the magnet member 20 as viewed in the Z direction coincides with the center position of the rotating shaft 40 and the disk member 10 as viewed in the Z direction. A predetermined magnetic pattern 20 a is formed on the magnet member 20.

  As the magnetic pattern 20a of the magnet member 20, for example, as shown in FIG. 2, the outer peripheral region of the half region of the magnet member 20 as viewed in the Z direction (for example, −X side in FIG. 2) is magnetized to the N pole. The inner peripheral region is magnetized to the S pole, and the other half region (for example, the + X side in FIG. 2) of the magnet member 20 is magnetized to the S pole. A configuration in which the peripheral region is magnetized in the N pole can be used. Of course, other forms may be adopted as the magnetic pattern 20a.

  The main body D is fixed to a housing 41 that is a non-rotating part of the motor device MTR. The main body D includes a detection substrate 30, an optical sensor 31, a magnetic sensor 32, a cylindrical member 33, and a control unit CONT.

  The detection substrate 30 is a plate-like member formed in a circular shape in plan view, for example. The detection substrate 30 is fixed to the cylindrical member 33 and the motor device MTR by, for example, three fixing members 51. Since the detection substrate 30 is fixed to the motor device MTR, the relative position between the detection substrate 30 and the motor device MTR does not change even if the rotation shaft 40 rotates. For example, a screw or the like is used as the fixing member 51. The fixing member 51 is attached so as to pass through the detection substrate 30 and the cylindrical member 33 so as to be difficult to insert into the + Z side surface of the motor device MTR.

  For example, the optical sensor 31 is disposed at a position overlapping the light reflection pattern 12a (optical pattern) when viewed in the Z direction. The optical sensor 31 has a light emitting unit and a light receiving unit (not shown). The optical sensor 31 is a part that detects the light reflection pattern 12a by emitting light from the light emitting unit toward the light reflection pattern 12a of the detection substrate 30 and reading the reflected light in the light receiving unit. The detection result is transmitted to the control unit CONT as an electrical signal.

  For example, two magnetic sensors 32 are provided at the center of the detection substrate 30 as viewed in the Z direction. The two magnetic sensors 32 each have a bias magnet (not shown) and a magnetoresistive element (not shown). The magnetic sensor 32 is arranged at a position shifted by 90 ° in the θZ direction, for example.

  The bias magnet forms a combined magnetic field with the magnetic field of the magnet member 20. As a material constituting the bias magnet, for example, a rare earth magnet having a large magnetic force such as samarium / cobalt can be cited. The bias magnet is disposed at a position that does not contact the magnetoresistive element and is not adjacent to the magnetoresistive element.

  The magnetoresistive element has two orthogonal repeating patterns formed by, for example, metal wiring. In the magnetoresistive element, the electric resistance decreases when the direction of the magnetic field is close to the direction perpendicular to the direction of the current flowing in the repetitive pattern. The magnetoresistive element converts the direction of the magnetic field into an electric signal by utilizing the decrease in electric resistance. The magnetoresistive element detects a combined magnetic field generated by the magnetic field of the magnet member 20 and the magnetic field of the bias magnet. The detection result is transmitted to the control unit CONT as an electrical signal.

  The control unit CONT obtains the rotation information of the rotation shaft 40 based on the output from the optical sensor 31 and performs the process of obtaining the rotation information of the rotation shaft 40 based on the output from the magnetic sensor 32. The rotation information includes information such as the number of rotations, the rotation direction, the rotation angle, and the rotation position of the rotation shaft 40, for example.

  The cylindrical member 33 is a support member that supports the detection substrate 30. The cylindrical member 33 is formed so as to surround the rotating portion R. The inner wall of the cylindrical member 33 is formed so as not to contact the rotating portion R at least in a state where the encoder EC is attached to the rotating shaft 40 of the motor device MTR.

  The −Z side surface 33 a of the cylindrical member 33 is in contact with the + Z side surface 41 a of the housing 41. On the contact surface 33a on the cylindrical member 33 side, for example, recesses (first recesses) 33b are formed at two locations in the X direction in FIGS. On the other hand, in the contact surface 41a on the motor device MTR side, for example, recesses (second recesses) 41b are formed in two places in the X direction in FIGS.

  As shown in FIGS. 1 and 2, the first recess 33 b and the second recess 41 b are formed at positions that overlap in the Z direction view. Thus, the 1st recessed part 33b and the 2nd recessed part 41b are formed in the corresponding position. Regarding the formation positions of the first concave portion 33b and the second concave portion 41b, when the insertion member 50 is inserted and the cylindrical member 33 and the housing 41 are locked, the light reflection pattern 12a and the magnetic pattern 20a of the rotating portion R are obtained. And the optical sensor 31 and the magnetic sensor 32 of the main body D are set to correspond to each other.

  For example, as shown in FIG. 2, the first concave portion 33 b and the second concave portion 41 b are both formed in a cylindrical shape and have the same inner diameter. The two first recesses 33b are formed so that the dimensions in the Z direction are equal. Also, the two second recesses 41b are formed so that the dimensions in the Z direction are equal.

  A common insertion member 50 is inserted into each of the first recess 33b and the second recess 41b. Here, for example, for the first recess 33b and the second recess 41b on the + X side in FIGS. 1 and 2, one insertion member 50 is inserted, and the first recess 33b and the second recess 41b on the −X side are inserted. The other insertion member 50 is inserted. The two insertion members 50 are formed corresponding to the shapes of the first recess 33b and the second recess 41b, respectively. In this embodiment, as the insertion member 50, for example, a pin member formed in a columnar shape is used. Of course, other modes may be adopted as the mode of the insertion member 50.

  As described above, the cylindrical member 33 and the casing 41 are locked by the insertion member 50. Therefore, the first recess 33 b is a locking portion that locks the cylindrical member 33 to the housing 41.

  In FIGS. 1 and 2, in order to show the positional relationship between the first recess 33b, the second recess 41b, and the insertion member 50, there is a slight gap between the insertion member 50 and the first recess 33b and the second recess 41b. Although it is shown that there is a gap, it is actually preferable that the gaps are arranged without gaps, for example. By arranging without any gap, the cylindrical member 33 and the casing 41 are positioned with high accuracy by the insertion member 50.

Next, a process of attaching the encoder EC configured as described above to the motor device MTR will be described.
First, as shown in FIG. 3, the rotating part R is fixed to the rotating shaft 40 (first fixing step). In this step, after the rotating shaft 40 is inserted into the insertion hole 11a of the rotating portion R, the rotating portion R is fixed to the rotating shaft 40 by a fixing mechanism (not shown). Next, as illustrated in FIG. 4, the insertion members 50 are inserted into the two second recesses 41 b of the housing 41, respectively. The insertion member 50 is inserted into the second recess 41b with at least a part protruding from the contact surface 41a to the + Z side.

  Next, as shown in FIG. 5, the main body D is installed on the contact surface 41a on the housing 41 side. At this time, a part of the insertion member 50 protruding to the + Z side of the contact surface 41a is inserted into the first recess 33b of the cylindrical member 33 (positioning step). In this step, the insertion member 50 is inserted across both the first recess 33b and the second recess 41b. Further, the contact surface 33a on the cylindrical member 33 side and the contact surface 41a on the housing 41 side come into contact with each other, and the cylindrical member 33 and the housing 41 are locked by the insertion member 50. By this step, the main body D is positioned so that the optical sensor 31 and the magnetic sensor 32 of the main body D are arranged at positions corresponding to the light reflection pattern 12a and the magnetic pattern 20a of the rotating part R, respectively.

  Next, as shown in FIG. 6, the main body D is fixed to the casing 41 by the fixing member 51 in a state where the main body D is positioned (second fixing step). As the fixing member 51, for example, a member having a dimension larger than the dimension of the main body D in the Z direction is used. In this step, the fixing member 51 is attached at a position different from the insertion member 50 as viewed in the Z direction. The fixing member 51 is attached so as to penetrate the detection substrate 30 and the cylindrical member 33 and bite into the housing 41. Through the above steps, the encoder EC shown in FIGS. 1 and 2 is attached to the motor device MTR.

Next, the operation of the encoder EC attached to the motor device MTR will be described.
When the rotating shaft 40 of the motor device MTR rotates, the rotating portion R fixed to the rotating shaft 40 rotates integrally with the rotating shaft 40. About the main-body part D, since it is not connected or contacted to the rotating shaft 40, it maintains the stationary state without rotating.

  When the rotating part R rotates, the light reflection pattern 12a formed on the rotating part R moves in the rotating direction. The optical sensor 31 emits light to the moving light reflection pattern 12a, and detects the rotation information (eg, rotation angle) based on the light reflection pattern 12a by reading the reflected light.

  When the rotating part R rotates, the magnet member 20 bonded to the rotating part R also rotates. When the magnet member 20 rotates, the combined magnetic field of the magnetic field formed by the magnetic pattern 20a of the magnet member 20 and the magnetic field formed by the bias magnet changes periodically. The magnetic sensor 32 detects rotation information (eg, multi-rotation information) based on the magnet member 20 (rotation axis) by detecting the change in the combined magnetic field.

  As described above, according to the present embodiment, the encoder EC has the light reflection pattern 12a and the magnetic pattern 20a and is fixed to the rotation shaft 40 of the motor device MTR, and the light reflection pattern 12a and the magnetic pattern. A main body D having an optical sensor 31 and a magnetic sensor 32 for detecting the pattern 20a and being fixed to the housing 41 of the motor device MTR, and a main body D provided on the main body D by being engaged with the housing 41. Since the plurality of first recesses 33b for positioning the optical sensor are provided, the positional adjustment blur between the light reflection pattern 12a and the magnetic pattern 20a and the optical sensor 31 and the magnetic sensor 32 is reduced. As a result, an encoder EC with less detection accuracy fluctuation between individuals can be obtained.

  Moreover, according to this embodiment, the 1st fixing process which fixes the said rotation part R to the rotating shaft 40 of the motor apparatus MTR, and the 2nd fixing process which fixes the said main-body part D to the housing | casing 41 of the motor apparatus MTR, And a positioning step of positioning the main body portion D by locking the first concave portion 33b provided in the main body portion D to the housing 41 prior to the second fixing step. Can be done in action. Since it is not necessary to adjust the position between the light reflection pattern 12a and the magnetic pattern 20a and the optical sensor 31 and the magnetic sensor 32, the encoder EC can be attached to the motor device MTR without depending on the skill of the operator. it can. Thereby, the fluctuation | variation of the detection accuracy between encoder EC individual | organism | solid can be decreased. Further, since it is not necessary to adjust the position, there is an advantage that the installation work of the encoder can be simplified or the work time can be shortened.

  Further, according to the present embodiment, the motor device MTR is attached to the rotary shaft 40 that is rotationally driven by the drive mechanism 43, the housing 41 that supports at least the rotary shaft 40, and the rotary shaft 40 and the housing 41. The encoder EC of the present invention is provided, and in the encoder EC, the rotating part R is fixed to the rotating shaft 40 and the main body part D is fixed to the housing 41, so that rotation information can be detected with high detection accuracy. A simple motor device MTR can be obtained.

The technical scope of the present invention is not limited to the above-described embodiment, and appropriate modifications can be made without departing from the spirit of the present invention.
In the above embodiment, the first recess 33b has a configuration in which the diameter of the first recess 33b is equal in the Z direction. However, the present invention is not limited to this. For example, the opening of the first recess 33b (on the −Z side) The end portion may be partially enlarged. Thereby, when attaching the main-body part D to the housing | casing 41, it can make it easy to insert the insertion member 50 in the 1st recessed part 33b.

  In the above embodiment, the first concave portion 33b as the locking portion is provided on the contact surface 33a of the cylindrical member 33. However, the present invention is not limited to this. For example, the first concave portion 33b is related to the inner surface or the outer surface of the cylindrical member 33. A configuration may be employed in which a joint portion is provided. In this case, the housing 41 is provided with a concave portion or a convex portion according to the arrangement and shape of the engaging portion.

  In the above embodiment, the configuration in which the main body D and the housing 41 are locked via the insertion member 50 has been described as an example. However, the present invention is not limited to this. For example, the cylindrical member 33 and the housing The structure which directly latches with the body 41 may be sufficient. In this case, the locking portion provided in the main body D may be formed in a shape corresponding to the shape of the housing 41, for example. For example, when the casing 41 has irregularities, the irregularities corresponding to the irregularities of the casing 41 are formed on the contact surface 33a of the cylindrical member 33 as the locking portions of the main body D. It doesn't matter.

  Further, in addition to the configuration of the above-described embodiment, for example, a guide groove for guiding the insertion member 50 to the first recess 33b may be provided on the contact surface 33a of the cylindrical member 33 or the like. Examples of the shape of the guide groove include a configuration in which a recess having a smaller dimension in the Z direction than the first recess 33b is formed in a region including the first recess 33b along the curved direction of the contact surface 33a. Thereby, the attachment work of the encoder EC can be further simplified.

    EC ... Encoder MTR ... Motor device R ... Rotating part D ... Main part CONT ... Control part 12a ... Light reflection pattern 20a ... Magnetic pattern 31 ... Optical sensor 32 ... Magnetic sensor 33 ... Cylindrical member 33a ... Contact surface 40 ... Rotating shaft 41 ... Housing 41a ... contact surface 50 ... insertion member

Claims (11)

A rotating part having a pattern and fixed to a rotating shaft member to be measured;
A detection unit for detecting the pattern, and a main body fixed to the non-rotating part of the measurement object;
An encoder comprising: a plurality of locking portions that are provided in the main body portion and position the main body portion by being locked to the non-rotating portion. The main body portion has a wall portion surrounding the rotating portion,
The encoder according to claim 1, wherein the locking portion is provided on the wall portion. The wall portion has a contact surface that contacts the non-rotating portion;
The encoder according to claim 2, wherein the locking portion is provided on the contact surface. The encoder according to any one of claims 1 to 3, wherein the locking portion is locked via an insertion member provided between the main body portion and the non-rotating portion. The locking portion has a first recess,
The non-rotating portion has a second recess;
The encoder according to claim 4, wherein the insertion member is inserted into the first recess and the second recess. The encoder according to claim 5, wherein the first concave portion of the locking portion is formed according to the arrangement of the second concave portion of the non-rotating portion. A rotating shaft member rotated by a drive mechanism;
A support member that supports at least the rotating shaft member;
The encoder according to any one of claims 1 to 6, which is attached to the rotating shaft member and the support member.
Among the encoders, the rotating part is fixed to the rotating shaft member, and the main body part is fixed to the support member. The locking portion provided in the main body has a first recess,
The support member has a second recess corresponding to the locking portion,
The motor device according to claim 7, further comprising an insertion member that is inserted over both the first recess and the second recess to lock the locking portion and the support member. The said 1st recessed part and the said 2nd recessed part are arrange | positioned so that the detection position by the said detection part may overlap on the said pattern in the state in which the said latching | locking part and the said supporting member were latched. Motor device. A first fixing step of fixing a rotating part having a pattern to a rotating shaft member to be measured;
A second fixing step of fixing a main body having a detection unit for detecting the pattern to the non-rotating part of the measurement object;
Prior to the second fixing step, a positioning step of positioning the main body portion by locking a locking portion provided in the main body portion to the non-rotating portion. The positioning step locks the locking portion and the rotary shaft member by inserting an insertion member over both the concave portion provided in the locking portion and the second concave portion provided in the non-rotating portion. The encoder mounting method according to claim 10, further comprising:

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