JP2006084409A - Magnetometric sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetometric sensor capable of disposing the magnetically sensitive face on the prescribed position with a prescribed attitude with a high precision even in the case the surface of the magnetically sensitive surface of the sensor holder is made reference plane. <P>SOLUTION: The magnetometric sensor 1 provided with the head 5 and the magnetic scale 3 in which the bottom surface 55 of the sensor holder 6 on which the magnetically sensitive surface 50 is formed by the magnetoresistive element, the flat reference plane 56 is formed wherein, only the central region formed with a magnetically sensitive surface 50 is formed protruding from the peripheral region forming the flat reference plane 56. For the small surface such the reference plane 56, the higher surface precision can be secured, consequently if the clearance or attitude of head 5 and the magnetically sensitive surface 50 to the magnetic scale 3 are set up on the basis of the reference plane 56, the highly precise setting can be performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a magnetic sensor device used for detecting a moving position of a movable part or the like in a machine tool or a mounting apparatus.

  In a magnetic sensor device such as a magnetic linear encoder, a head mounted with a magnetoresistive element constituting a magnetosensitive surface, and an S pole and an N pole are alternately arranged along the relative movement direction of the head to face a magnetic scale. The magnetic head is disposed, and the relative movement between the head and the magnetic scale is detected magnetically, and the movement position, movement speed, and the like are detected (for example, see Patent Documents 1 and 2).

Here, the magnetoresistive element is held by a sensor holder made of an aluminum die cast product, a resin molded product, or a machined product. In addition, since the magnetosensitive surface constituted by the magnetoresistive element needs to be arranged with a certain gap from the magnetic scale and without being inclined with respect to the magnetic scale, the bottom surface of the sensor holder and the magnetosensitive surface are The position and orientation of the sensor holder (magnetic sensitive surface) are adjusted so that they are located in the same plane, and the entire bottom surface of the sensor holder is the reference plane.
JP-A-7-198365 JP 58-66001 A

  However, when the sensor holder is composed of an aluminum die-cast product, a resin molded product, or a machined product, it is difficult to ensure planar accuracy over the entire bottom surface of the sensor holder that should be the reference surface for the magnetically sensitive surface. For this reason, if the position and orientation of the sensor holder and the magnetic sensitive surface are adjusted with the entire bottom surface of the sensor holder as the reference surface, a large error occurs in the gap dimension with the magnetic scale, and the magnetic sensitive surface is inclined. There is a problem.

  In view of the above problems, the problem of the present invention is that even when the surface of the sensor holder on which the magnetosensitive surface is formed is used as a reference, the magnetosensitive surface can be placed at a predetermined position and in a predetermined posture with high accuracy. The object is to provide a magnetic sensor device.

  In order to solve the above problems, in the present invention, a head in which a magnetoresistive element constituting a magnetosensitive surface is held by a sensor holder, and S poles and N poles are alternately arranged along the relative movement direction of the head. In the magnetic sensor device having a magnetic scale opposed to the magnetosensitive surface, the surface of the sensor holder on which the magnetosensitive surface is formed has a height position of the magnetosensitive surface on the surface. The reference plane shown is configured as a region partially protruding from the other regions.

  In the present invention, the reference surface with respect to the magnetosensitive surface is not the entire surface on which the magnetosensitive surface is formed, but a partial region thereof. If such a partial region is used, high planar accuracy is ensured. Is also easy. Therefore, according to the present invention, it is possible to form a reference surface with high planar accuracy on the sensor holder. Therefore, if the position and orientation of the magnetosensitive surface are set based on the reference surface, the magnetosensitive surface is highly accurate. Can be placed in a predetermined position at a predetermined position.

  In the present invention, on the surface of the sensor holder on which the magnetosensitive surface is formed, for example, a region including the magnetosensitive surface protrudes from the peripheral region as the reference surface.

  In this case, an opening for exposing the magnetoresistive element is formed in the reference surface, and the magnetoresistive element is disposed inside the opening so that the magnetosensitive surface and the reference surface are at the same height position. It is preferable that they are arranged.

  In this invention, the structure by which the said reference surface was formed in the peripheral area | region which avoided the said magnetic sensitive surface may be sufficient as the surface in which the said magnetic sensitive surface of the said sensor holder was formed. With this configuration, since the reference surface consisting of the protrusions is formed in the peripheral region, when the sensor holder is placed on a table or the like with the surface on which the magnetic sensitive surface of the sensor holder is formed as a mounting surface In addition, there is an advantage that the sensor holder is placed on the table in a stable state without tilting.

  In the present invention, it is preferable that only the reference surface is machined on the surface of the sensor holder on which the magnetosensitive surface is formed. If comprised in this way, the plane precision of a reference plane can be improved. Further, since the reference surface is formed only in a part of the region, the time required for the machining operation is short unlike the case of machining the entire surface.

  In the head of the magnetic sensor device according to the present invention, the reference surface with respect to the magnetic sensitive surface is a partial region of the surface on which the magnetic sensitive surface is formed. It is easy to secure. Therefore, according to the present invention, it is possible to form a reference surface with high planar accuracy on the sensor holder. Therefore, if the position and orientation of the magnetosensitive surface are set based on the reference surface, the magnetosensitive surface is highly accurate. Can be placed in a predetermined position at a predetermined position. Therefore, a magnetic sensor device with high detection sensitivity can be realized.

  The best mode for carrying out the present invention will be described with reference to the drawings.

[Configuration of magnetic sensor device]
(overall structure)
FIG. 1 is an explanatory diagram of a magnetic sensor device (magnetic linear encoder) to which the present invention is applied. In the following description, among the three orthogonal directions, the width direction of the magnetic scale is the X direction, the length direction of the magnetic scale is the Y direction, and the height direction is the Z direction.

  In FIG. 1, a magnetic sensor device 1 of this embodiment is a magnetic linear encoder, and a head 5 having a magnetosensitive surface formed on the bottom surface by a magnetoresistive element, and a magnetic scale 3 facing the magnetosensitive surface of the head 5. And have. The magnetic scale 3 is magnetized such as A phase, B phase, Z phase, etc., and N poles and S poles are alternately arranged along the length direction (movement direction). In such a magnetic sensor device 1, the magnetic scale 3 is linearly disposed on the side of a movable body such as a moving table, while the head 5 is disposed so as to face the magnetic scale 3, and output from the head 5. Based on the signal, the moving position and moving speed of the moving table are detected.

(Configuration of head 5)
2A and 2B are explanatory views of the head used in the magnetic sensor device shown in FIG. 1 as viewed from the bottom side provided with a magnetic sensitive surface. 3A and 3B are an explanatory diagram showing a positional relationship between the head and the magnetic scale in the magnetic sensor device shown in FIG. 1, and a right side view of the head.

  As shown in FIG. 1, FIG. 2 (a), (b), and FIG. 3 (a), (b), the head 5 includes a sensor holder 6 made of a substantially rectangular parallelepiped-shaped aluminum die-cast product, A rectangular cover 61 covering the right opening of the sensor holder 6 and a cable 7 connected to the sensor holder 6 are provided. The sensor holder 6 has a cable insertion hole 67 formed on the back surface, and a hole 68 that can be used as a cable insertion hole on the front surface. For this reason, even when the cable 7 is pulled out from any side of the sensor holder 6, the common sensor holder 6 can be used.

  In the sensor holder 6, an opening 57 is formed in the bottom surface 55 facing the magnetic scale 3, and the magnetoresistive element 10 is disposed in the opening 57, so that a magnetosensitive surface is formed on the outer surface of the magnetoresistive element 10. 50 is configured.

  Further, in this embodiment, on the bottom surface 55 of the sensor holder 6, a flat reference surface in which only the central region where the magnetosensitive surface 50 is formed partially protrudes by 0.2 mm to 1.0 mm from the peripheral region. The reference surface 56 is about ½ times the area of the entire bottom surface 55. Here, the outer surface (the magnetosensitive surface 50) of the magnetoresistive element 10 is located on the same plane as the reference surface 56 of the sensor holder 6, and the reference surface 56 is the magnetosensitive surface 50 at the bottom surface 55. Indicates the height position.

(Assembly method and position adjustment method of the head 5)
When assembling the head 5 having such a configuration, first, the magnetoresistive element 10 to which a flexible substrate (not shown) is connected is disposed in the opening 57 and the back side of the magnetoresistive element 10 is bonded to the adhesive. To fix to the sensor holder 6. At that time, the position of the magnetoresistive element 10 is adjusted so that the outer surface (the magnetosensitive surface 50) of the magnetoresistive element 10 is at the same height as the reference surface 56. Next, the periphery of the magnetoresistive element 10 is filled with the sealant 91 in the opening 57, and the magnetoresistive element 10 is fixed to the sensor holder 6. Next, after performing work such as connecting the flexible board to a circuit board (not shown), the cable 7 is inserted into the sensor holder 6 through the cable insertion hole 67 and the cable 7 is connected to the circuit board. To do. After that, the cover 61 is attached so as to cover the opening of the sensor holder 6. In this way, the head 5 is completed.

  For the head 5 configured as described above, the bottom surface 55 on which the magnetosensitive surface 50 is formed needs to be accurately opposed to the magnetic scale 3. Therefore, in the present embodiment, when the head 5 and the magnetic scale 3 are arranged as shown in FIG. 1, the reference surface 56 of the bottom surface 55 of the head 5 is brought into contact with the upper surface of the magnetic scale 3 so that the reference posture of the head 5 is reached. Then, the head 5 is lifted from the magnetic scale 3 by a predetermined dimension, and the position and posture of the head 5 are determined. As a result, the position and orientation of the magnetosensitive surface 50 are determined with reference to the reference surface 56.

(Main effects of this form)
As described above, in the present embodiment, on the bottom surface 55 of the head 5, the central region including the magnetosensitive surface 50 is a surface protruding by 0.2 mm to 1.0 mm from the peripheral region as the reference surface 56. The area of the reference surface 56 is only about ½ of the entire area of the bottom surface 55 and is narrow. Therefore, when the sensor holder 6 is manufactured by aluminum die casting, high planar accuracy can be ensured in a narrow region such as the reference surface 56 alone. In addition, after the sensor holder 6 is manufactured by aluminum die casting, it is easy to machine only the reference surface 56 to ensure high planar accuracy on the reference surface 56. That is, of the bottom surface 55 of the head 5, only the center region of the bottom surface where the magnetosensitive surface 50 is formed is the reference surface 56, so that the region to be machined is narrow and the processing time is short.

  Therefore, according to the present embodiment, when the reference posture is determined by bringing the bottom surface 55 of the head 5 into contact with the top surface of the magnetic scale 3, only the reference surface 56 with high plane accuracy contacts the top surface of the magnetic scale 3. The entire surface 56 is securely in close contact with the magnetic scale 3 and the head 5 can be accurately positioned. Accordingly, if the head 5 is lifted by a predetermined dimension in this posture, the gap size and posture between the magnetic sensitive surface 50 and the magnetic scale 3 can be set with high accuracy, and therefore the magnetic sensor device 1 having high sensitivity. Can be configured.

  Further, since the magnetosensitive surface 50 (reference surface 56) is located at a position protruding from the bottom surface 55 of the sensor holder 6, the gap between the head 5 and the magnetic scale 3 is looked in with the head 5 facing the magnetic scale 3. The state of the magnetosensitive surface 50 can also be confirmed.

[Other embodiments]
In the above embodiment, in the bottom surface 55 of the sensor holder 6, the central region of the bottom surface 55 including the magnetosensitive surface 50 is a reference surface 56 that partially protrudes from the peripheral region, but as shown in FIG. 4. In addition, the reference surface 59 may be formed in the peripheral region avoiding the magnetic sensitive surface 50 on the bottom surface 55 of the sensor holder 6. That is, in the example shown in FIG. 4, an opening 57 is formed in the bottom surface 55 of the sensor holder 6, and the magnetoresistive element 10 is arranged in the opening 57 and fixed with the sealant 91. A magnetically sensitive surface 50 is formed by the outer surface of 10.

  In addition, two reference surfaces 59 are formed on both sides of the magnetosensitive surface 50 on the bottom surface 55 of the sensor holder 6, and the reference surfaces 59 are only 0.2 mm to 1.0 mm than other regions. It is partially protruding. Here, the outer surface (the magnetosensitive surface 50) of the magnetoresistive element 10 is located on the same plane as the bottom surface 55 of the sensor holder 6, while the projecting dimension of the reference surface 59 from the bottom surface 55 is 0. It is set to any value from 2 mm to 1.0 mm. Therefore, the reference surface 59 indicates the height position of the magnetosensitive surface 50 at the bottom surface 55.

  Even in such a configuration, when the sensor holder 6 is manufactured by aluminum die casting, if only the reference surface 59 is provided, the area is narrow, and therefore, high planar accuracy can be secured on the reference surface 59. Even when the sensor holder 6 is manufactured by aluminum die casting, even when only the reference surface 59 is machined to ensure high planar accuracy on the reference surface 59, the machining area is small, so the processing time is short. That's it.

  Therefore, according to this embodiment, since the sensor holder 6 includes the reference surface 59 with high planar accuracy, when the reference posture is determined by bringing the bottom surface 55 of the head 5 into contact with the upper surface of the magnetic scale 3, Only the high reference surface 59 contacts the upper surface of the magnetic scale 3. Accordingly, the entire reference surface 59 is in close contact with the magnetic scale 3, and the posture of the head 5 can be accurately obtained. Accordingly, if the head 5 is lifted by a predetermined dimension in this posture, the gap size and posture between the magnetic sensitive surface 50 and the magnetic scale 3 can be set with high accuracy, and therefore the magnetic sensor device 1 having high sensitivity. Can be configured.

  Further, since the reference surface 59 is located at a position protruding from the bottom surface 55 of the sensor holder 6, the head 5 is opposed to the magnetic scale 3 and the gap between the head 5 and the magnetic scale 3 is looked into. 50 states can also be confirmed.

  Furthermore, when the sensor holder 6 is placed on a table or the like with the bottom surface 55 on which the magnetic sensitive surface 50 of the sensor holder 6 is formed as a mounting surface, the sensor holder 6 is in a stable state without being tilted. There is an advantage of being placed on top.

  In addition, although the case where the sensor holder 6 was comprised with the aluminum die-cast goods was demonstrated in the said form, you may apply this invention when the sensor holder 6 is comprised from a resin molded product or a machined product.

It is explanatory drawing of the magnetic sensor apparatus (magnetic type linear encoder) to which this invention is applied. (A), (b) is explanatory drawing which looked at the head used for the magnetic sensor apparatus shown in FIG. 1 from the side of the bottom face provided with the magnetosensitive surface. (A), (b) is explanatory drawing which shows the positional relationship of the head and magnetic scale in the magnetic sensor apparatus shown in FIG. 1, and the right view of a head. (A), (b) is explanatory drawing which shows the positional relationship of another head and magnetic scale used for the magnetic sensor apparatus to which this invention is applied, and the right view of a head.

Explanation of symbols

1 Magnetic sensor device (magnetic linear encoder)
3 Magnetic scale 5 Head 6 Sensor holder 7 Cable 10 Magnetoresistive element 50 Magnetosensitive surface 55 Bottom surface 56, 59 Reference surface of the head

Claims (5)

A head in which a magnetoresistive element constituting a magnetosensitive surface is held by a sensor holder, and a S pole and a N pole are alternately arranged along the relative movement direction of the head, and a magnet arranged opposite to the magnetosensitive surface. In a magnetic sensor device having a scale,
On the surface of the sensor holder on which the magnetosensitive surface is formed, a reference surface indicating the height position of the magnetosensitive surface on the surface is configured as a region partially protruding from other regions. A magnetic sensor device.   The magnetic sensor device according to claim 1, wherein a region including the magnetic sensitive surface protrudes from a peripheral region as the reference surface on the surface of the sensor holder on which the magnetic sensitive surface is formed. In Claim 2, the opening for exposing the magnetoresistive element is formed in the reference plane,
The magnetic sensor device, wherein the magnetoresistive element is arranged inside the opening so that the magnetosensitive surface and the reference surface are at the same height position.   The magnetic sensor device according to claim 1, wherein the reference surface is formed in a peripheral region avoiding the magnetic sensitive surface on the surface of the sensor holder on which the magnetic sensitive surface is formed.   5. The magnetic sensor device according to claim 1, wherein only the reference surface is machined on the surface of the sensor holder on which the magnetosensitive surface is formed. 6.

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