JPH05248806A - Magnetic measuring method - Google Patents

Abstract

PURPOSE:To obtain a method enabling magnetic measurement by its direct application to an optional object to be measured. CONSTITUTION:According to this magnetic measuring method, the magnetic scale is read by a magnetic head set confronting to the scale, thereby to measure the relative movement of the scale and the head. A surface treatment part 3a is directly partially formed on an object 3 to be measured in a direction of the relative movement so as to improve the magnetic characteristics. The magnetic scale is obtained by magnetizing and recording the surface treatment part. The magnetic scale directly recorded on the object is read by the magnetic head 1. As for the surface treatment to improve the magnetic characteristics, the part 3a may be nitrified, carbonized, turned to boron or iron or a rare earth, or subjected to a combined treatment of the above processes. Moreover, as for the means for the surface treatment, laser or discharge/deposition process may be utilized. It is also recommended that the surface treatment is conducted in the magnetic field to record the magnetic scale.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic measuring method.

[0002]

2. Description of the Related Art A conventional measuring technique uses a magnetic scale made of a band-shaped permanent magnet material, and a magnetic scale is intermittently magnetized at a predetermined pitch on the magnetic scale. It is mounted on a moving table or the like, and a magnetic head for detection is made to face the scale plate surface to read the magnetic scale to measure the relative movement amount and position of the object to be measured.

However, the magnetic scale may not be able to be attached and fixed to an arbitrary object or a moving body in terms of accuracy or mechanism, and even if it can be attached, the shape, dimensions, etc. of the magnetic scale are different from each other. There are drawbacks that must be produced according to.

[0004]

SUMMARY OF THE INVENTION In view of such a point, the present invention arbitrarily applies to an object to be measured to enable magnetic measurement, for example, a table, a rack, a gear, a caliper, a motor. An object of the present invention is to provide a magnetic measurement method that can be easily applied to measurement of parts such as a rotor, a shaft, a screw, a bearing, and other sliding parts and fixed parts.

[0005]

SUMMARY OF THE INVENTION The above object is to provide a magnetic measuring method for measuring the relative movement between the two by reading a magnetic scale with a magnetic head opposed to the magnetic scale, and measuring the relative movement direction on the object to be measured. Along the surface of the magnetic head to directly improve the magnetic characteristics, and to magnetize and record the magnetic scale on the surface-treated portion. The magnetic scale directly recorded on the object to be measured is the magnetic head. This can be achieved by a magnetic measurement method characterized by being configured to read by.

As the surface treatment for improving the above-mentioned various magnetic properties, nitriding, carbonization, boride, ironization, rare earth or a combination treatment thereof can be used. Further, as the means for the surface treatment, laser is used. Or electric discharge welding (micro-welding) can be used. It is also recommended that the surface treatment for improving the above-mentioned various magnetic properties be performed in a magnetic field for recording a magnetic scale.

[0007]

According to the present invention, as described above, the surface of the object to be measured is directly subjected to the surface treatment for improving the magnetic characteristics along the relative movement direction, and the surface treated portion is provided with the magnetic scale. Since the magnetic scale is magnetized and recorded, and the magnetic scale directly recorded on the object to be measured is read by the magnetic head, the magnetic scale can be directly magnetized and formed on any object or machine part. The position, movement amount, speed, acceleration, rotation speed, etc. of an object can be easily detected and measured without contact or with light contact.

Further, by performing the surface treatment by laser or electric discharge welding, partial nitriding, carbonization,
The magnetic property improving treatment by boride, ironization, rare earth conversion, etc. can be carried out very easily, and the treatment can be carried out easily without changing the material and characteristics of the object base material.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings. FIG. 1 shows an example of surface treatment using a laser.
Is a laser semiconductor, a laser head formed of a lens,
Reference numeral 2 is a drive power source for pulse-driving a laser semiconductor, 3 is a moving table of a mechanical device, and a motor 4 is provided in the X and Y axis directions, respectively.
The movement control is performed by 5. 6 is an NC controller,
The drive motors 4 and 5 are controlled. 7 is N near the focal point of the laser beam emitted from the laser head 1 onto the table 3.
₂ is an injection nozzle for supplying gas, 8 is a magnetic head for magnetizing, and the needle-like tip 81 is opposed to the table 3 and the exciting coil 82
Have. Reference numeral 9 is a power source for coil excitation, which performs pulse excitation.

Steel is usually used for the moving table 3,
A laser beam is focused and emitted from the laser head 1 onto the table surface. The movement of the table 3 is moved in the surface treatment direction by the laser by the NC control device 6, the laser drive power source 2 is controlled in conjunction with this movement control, the drive pulse is supplied to the laser semiconductor, and the pulse laser is generated by the pulsed oscillation. Control to irradiate. N ₂ gas is supplied from the nozzle 7 to the laser-irradiated portion, and the portion heated by laser irradiation in this gas atmosphere is nitrided, so that a nitriding portion 3a is partially formed on the table surface. .. When a desired nitriding treatment is performed by irradiating one place on the table 3 with a plurality of pulse lasers, the NC control device 6
The NC controller 6 controls the drive power supply 2 so that the table 3 is moved a predetermined distance and the laser pulse irradiation is repeated. The control of the drive pulse of this power supply 2 is
By controlling the pulse train to be interrupted intermittently as shown in FIG. 2 and performing pulsed laser irradiation corresponding thereto, nitrided portions 3a are formed on the table 3 at predetermined equal intervals in the moving direction. can do. The table 3 that is sequentially controlled to move while performing this nitriding process moves to the facing portion of the magnetizing head 8, and when the head tip 81 faces the nitriding portion 3a of the table 3, the excitation power supply 9 is driven. The nitriding portion 3a is magnetized. In this case, the excitation power source 9
Is also controlled by the NC controller 6 in association with the movement of the table 3, and the magnetization control is performed at precise predetermined intervals corresponding to the nitriding portion 3a.

Although the above nitriding treatment improves the magnetic characteristics, the magnetic characteristics are also improved by other treatments such as carbonization, boride, ironization, and rare earth treatment. The permanent magnetizing process is performed on the basis of Hc = 1KOe or more and residual magnetic flux density Br = 4KG or more. The injection treatment substance to be supplied to the laser beam irradiation portion can be supplied as a powder or a powder-gas mixture in addition to the gas body,
Alternatively, it can be supplied in a coated state on the surface of the processed material. The laser beam used for irradiation varies depending on the material to be processed, etc., but usually 1 to 10 at a power density of about 10 ⁵ to 10 ⁸ W / cm ² .
By performing irradiation treatment at a speed of about 5 m / Sec, magnetic characteristics can be improved. The magnet base material to be treated is coated or diffused by laser heating to improve the magnet characteristics. The relationship between the magnet base material and the magnetic characteristics is as shown in the table below. Each element is represented by a weight ratio, and Bal is a balance%.

[0012]

[Table 1] No. Cu Co Fe NB Nd Pr Sm C Hc: KOe Br: KG Magnetic field 1 7.8 Bal 16 0.01 23.9 9 6 12KOe 2 7 Bal 16 0.01 2.1 24.7 8 5.7 20KOe 3 ≈ 90 ≈ 10 0.08 28 4 65.5 1.5 2.0 30 1 7 9 5 61 2.0 2.5 19 15.5 5.4 7 6 64 3 33 4.2 3.7 7 50.7 1.5 1.5 44 2.3 12.2 6.5 8 3.2 10 72 1.4 4.8 8.6 9.4 10.9

In the above table, for compositions other than No. 3, coercive force Hc = 1 KOe or more, residual magnetic flux density Br = 4
Above KG, both are practical. The width in the pitch direction of the magnetic grid for forming the magnetization depends on the size and shape of the magnetization head and the method of magnetization, but it is possible to easily form the magnetization narrower than 0.1 to 0.2 mm. Also, the magnetic lattice is perpendicular magnetization,
Both horizontal magnetizations can be magnetized, but vertical magnetization can form extremely high-density scales.

The material of the component base material can be applied to any material component such as ferrous material, non-ferrous material, and soft iron material, and is not limited to a table, but also a rack, a gear, a caliper, a rotor of a motor, It can be arbitrarily applied to shafts, screws, bearings, other moving members, sliding movable members, fixed parts of machines, and the like. The magnet characteristic improving process may be a belt-shaped continuous process by laser scanning control. In addition, an MR element or Hall element is used for the read detection head of the magnetic scale formed by magnetization, but the amount of movement, position, speed, rotation of the relative movement can be made without contact with the magnetized portion or with light contact. The speed and the like can be detected, and in particular, since the magnetized portion is surface hardened by nitriding, carbonization, boration, etc., wear resistance and long life can be measured even when contacting and sliding is detected.

FIG. 3 shows an embodiment in which surface treatment is carried out by electric discharge welding. Reference numeral 10 is a rotary electrode in which the peripheral portion of the disk is formed to be narrow and sharp. In this state, it is rotatably provided around the central rotating shaft 11, and while being rotated by the motor 12, a pulse voltage is applied from a terminal 15 to generate a discharge for processing. Reference numeral 13 is a control motor for servo-controlling the rotary electrode 10 so that the rotary electrode 10 is always in light contact with the table 3, 14 is a nozzle for supplying N ₂ gas to the discharge gap, and 16 is an exciting coil for magnetization.

Nitrogen, carbonization,
When an electrode containing a metal element to be treated for boride or the like is used, and the electrode is rotated in a state of being in slight contact with the surface of the table 3, the tip repeats microvibration of contact separation on the surface of the table. By applying a pulse voltage from the terminal 15 to this gap, a pulse discharge is generated, and the sharp ends of the rotary electrode 10 which are sharply formed to reduce the heat capacity are weld-coated on the surface of the table 3 in minute amounts. At the same time as the coating, the welding layer is partially diffused and bonded in the table base material by the heat of discharge and the electric field to form a strong bonding layer. Further, the N ₂ gas supplied from the nozzle 14 is also diffused in the coating layer, and the nitriding treatment is also performed at the same time, so that the treatment for improving the magnetic characteristics can be performed.

Further, the rotating electrode 10 is excited by exciting the magnetizing coil 16 at the same time as the magnetic characteristic improving process by the electric discharge welding.
Can also be used as a magnetic head to perform the magnetization process. The magnetized magnetic flux can be strongly magnetized through the support member 17 that supports one end of the rotating shaft 11.
A roller is interposed on the contact surface of the support member 17 with the table 3, so that the table 3 can be moved smoothly. The NC controller 6 moves the table 3 to improve the magnetic characteristics and magnetizes the magnetic scale. The forming process is simultaneously and stably performed along the moving direction of the table 3.

Other gas may be supplied from the nozzle 14, for example, by supplying a magnet basic powder material for welding coating,
A mixture of gas and powder can be supplied. It is also possible to treat the welding coating layer or the diffusion layer so as to have permanent magnet characteristics by selecting the material of the electrode.

The pulse discharge machining conditions in the electric discharge welding are, for example, a current peak value Ip = 3 to 5 A and a pulse width τ _on = 50 μs to 1 ms.
The rotational speed of the electrode 10 is processed so that the rotational contact speed of the peripheral portion of the electrode with respect to the table 3 is about 5 to 30 m / s.

As the shape of the rotating electrode, a rotating body formed by pressing a thin plate 18 (having a thickness of 10 to 100 μm) made of a covering material with a support 19 from both sides as shown in FIG. 4 can be used. Moreover, not only a circular plate but also a rod-shaped, linear, or chip-shaped electrode can be used. While the electrode is vibrated in contact with the substrate, pulse discharge is generated, and the electrode tip melted by the discharge is divided into minute groups. It is possible to form a uniform thin layer on the entire surface of the strip by coating the material by transfer welding and by applying the coating layer in the direction of writing the magnetic scale. The magnetic writing of the scale scale on the formed coating layer can be performed by moving the magnetizing head along the surface of the coating layer.

FIG. 5 shows an embodiment of the magnetic scale and the detection head thereof formed as described above. Reference numeral 20 is a read magnetic head, which is elastically supported by a spring 22 on a support 21 to form the magnetic scale. It is adapted to come into light pressure contact with the formed component 23. By applying a spring pressure of about 50 to 150 g to bring the components into contact with each other, stable sliding detection can be performed without causing chattering due to vibration due to the movement when the components 23 move relative to each other. Magnetic head
An MR element or a Hall element is used as the detection element of 20, and this is wrapped with a polymer resin case of nylon, Delrin, acetal or the like to have weather resistance, heat resistance, wear resistance and the like.
The thickness of the sliding layer between the sensing element and the scale contact surface is
Stable magnetism can be detected by adjusting the thickness of the sliding layer so as to be about 50 to 150 μm.

In the above, the embodiment in which the magnetic scale in the lengthwise direction is magnetized and measured on a long part has been mainly described, but for rotary parts such as a rotary shaft and rollers,
If the band-shaped magnetic characteristic improving process and the magnetic scale magnetizing process are performed in the circumferential direction of the rotating body, for example, in a part of the rotating body, the same angle, rotational speed, rotational speed, etc. as those of the rotary encoder can be detected. You can take measurements.

[0023]

As described above, according to the present invention, for example, a machine table, a rack, a gear, a caliper, a rotor of a motor of an object whose position, moving length, speed, acceleration, rotational speed, etc. are to be measured. Since magnetic scales are directly formed on parts such as shafts, screws, other sliding movable parts or fixed parts, rollers and ball bearings for detection and measurement, it is extremely easy and precise to measure the position of any object. Can be measured. In addition, the measurement is performed by directly partially performing a surface treatment on the object to be measured in the relative movement direction to improve the magnetic characteristics, and magnetizing a magnetic scale on the treated portion to form a magnetized magnetic scale. It is designed to be read by a magnetic head, and the surface treatment is such that nitriding, carbonization, boride, ironization, rare earth or a composite treatment thereof is performed. Therefore, any object, mechanical part, etc. Moreover, it is possible to easily magnetize both large and small parts, and both inside and outside to form a magnetic scale to easily and accurately measure the position and the like.

Further, by performing the surface treatment by laser or electric discharge welding, partial nitriding, carbonization,
The magnetic property improving treatment due to boride, ironization, rare earth, etc. can be performed extremely easily, and the treatment of this minute portion or only the surface layer portion can be easily performed without changing the material and characteristics of the base material. In addition, the treatment such as carbonization has the effect of increasing the surface hardness, improving the wear resistance, and extending the scale life.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of an apparatus for carrying out a magnetic measurement method according to the present invention.

FIG. 2 is an operation explanatory view of the laser irradiation.

FIG. 3 is an explanatory diagram showing another example of an apparatus for carrying out the magnetic measurement method according to the present invention.

FIG. 4 is a partial configuration explanatory view showing still another example of an apparatus for carrying out the magnetic measurement method according to the present invention.

FIG. 5 is an explanatory diagram of a scale and a magnetic head.

[Explanation of symbols]

 1 Laser head 2 Laser drive power supply 3 Base material table 4,5 Motor 6 NC controller 7 Nozzle 8 Magnetic head for magnetization 10 Rotation electrode 12 Rotation motor 15 Discharge power supply terminal 16 Magnetization coil

Claims (5)

[Claims] 1. A magnetic measuring method for measuring a relative movement between a magnetic scale and a magnetic head, which is placed opposite to the magnetic scale, to directly and partially measure on an object (3) to be measured along the relative movement direction. Surface treatment to improve various magnetic properties (3
A magnetic measuring method characterized in that a) is applied, a magnetic scale is magnetized and recorded on the surface-treated portion, and the magnetic scale directly recorded on the object to be measured is read by a magnetic head. 2. The magnetic measuring method according to claim 1, wherein the surface treatment for improving various magnetic properties is nitriding, carbonization, boride, ironization, rare earth or a composite treatment thereof. 3. The magnetic measurement method according to claim 2, wherein the surface treatment for improving the magnetic characteristics is performed by using a laser. 4. The magnetic measuring method according to claim 2, wherein the surface treatment for improving the magnetic characteristics is performed by electric discharge welding. 5. The surface treatment for improving the magnetic characteristics is performed in a magnetic field for recording a magnetic scale.
Alternatively, the magnetic measurement method described in 4 above.