JPS6375601A - Leak magnetic field type positioner - Google Patents

Abstract

PURPOSE:To enhance the linearity and reliability of detected output, by allowing the direction of a leak magnetic field to cross the magnetizing direction of the magnetic body pattern of a magnetic resistor element at a right angle. CONSTITUTION:A leak magnetic field type linear positioner 21 is loaded with a closed magnetic circuit 6 consisting of electromagnets 2, 3 and magnetic plates 4, 5 and a magnetic detection element 7, and equipped with the carrier 23 allowed to move in the circuit 6 in the longitudinal direction thereof while guided by a guide shaft 22. The magnetic plate 4 is connected to the N-pole surfacer of the magnet 2 and the S-pole surface of the magnet 3 while the magnetic plate 5 is connected to the S-pole surface of the magnet 2 and the N-pole surface of the magnet 3 and both plates 4, 5 are parallel to the shaft 22. The magnetic body pattern 11 of the element 7 is positioned on the center line CL in the opposed direction of the plates 4, 5 and made movable so that a leak magnetic field Hex crosses a long axis 12 at a right angle.

Description

[Detailed Description of the Invention] [Summary] In a leakage magnetic field type positioner in which a magnetic resistance element moves inside a closed magnetic circuit and detects the position and amount of movement of the element, the direction of the leakage field and the magnetic resistance are detected. By making the magnetization direction of the magnetic material pattern of the element almost perpendicular, the linearity and reliability of the detection output are improved.

[Industry” second field of use]

The present invention takes into consideration the leakage magnetic field type positioner, especially the nonlinearity of the leakage magnetic field in the closed magnetic circuit and the effect of reducing the magnetic resistance element.
Concerning improvements that improve detection performance and reliability.

[Conventional technology]

Fig. 3 is a plan view showing the main configuration of a positioner according to the prior art, Fig. 4 is an enlarged plan view of a part of the magnetic body pattern of the magnetoresistive element, and Fig. 5 shows the leakage of the closed magnetic circuit in Fig. 3. FIG. 3 is a plan view showing a magnetic field.

In FIG. 3, the positioner 1 includes a pair of permanent magnets (or electromagnets) 2 and 3 and a pair of magnetic plates (for example, 0.4 mm thick).
It consists of a closed magnetic circuit 6 consisting of a steel plate (4.5 mm) and a carrier 8 on which a magnetic detection element 7 is mounted and moves along a guide shaft 9 in the length direction of the closed magnetic circuit 6. However, the magnetic plate 4 is connected to the N pole face of permanent magnet 2 and the S pole face of permanent magnet 3, and the magnetic plate 5 is connected to the S pole face of permanent magnet 2 and the N pole face of permanent magnet 3.
The magnetic plates 4 and 5 and the guide shaft 9 are parallel to each other.

In this positioner 1, a leakage magnetic field Hex is formed in the closed magnetic circuit 6 as shown by the arrow in the figure, and the strength of the leakage magnetic field Hex is approximately inversely proportional to the distance from the permanent magnets 2 and 3. Therefore, the leakage magnetic field Hex is detected by the magnetic detection element 7.
The position and amount of movement of the magnetic detection element 7 can be determined from the detection signal.

In FIG. 4, the magnetic material pattern 11 of the magnetic detection element 7 that utilizes the magnetic resistance of ferromagnetic metal is formed from a magnetic thin film such as permalloy, and has a meandering shape in which a plurality of long axes 12 are connected by a short axis 13. After imparting uniaxial magnetic anisotropy in the longitudinal direction of the long axis 12, conductive layers 14 are deposited diagonally at regular intervals, resulting in a so-called barber pole shape. .

When an external magnetic field (leakage magnetic field) Hex is applied in a direction perpendicular to the length direction of the long axis 12 of the magnetic material pattern 11, the conductor layer 14 for obtaining a linear output proportional to the strength of the external magnetic field Hex is , formed in a striped shape with an appropriate inclination on the long axis 12,
The current i flowing through the magnetic material pattern E 1 in the shortest distance and the magnetization direction M are approximately 45 degrees (or 135 degrees, 225 degrees, 31 degrees).
5 degrees).

On the other hand, as shown by many arrows in FIG.
(or 3) (tilted, this slope is the magnetic plate 4.5
This tendency becomes stronger as it approaches the permanent magnet 2.

[Problem that the invention seeks to solve]

FIG. 6 is a plan view showing the relationship between the leakage magnetic field shown in FIG. 4 and the magnetization direction M of the magnetic material pattern shown in FIG. When tilted by 1, the leakage magnetic field Hex is in the magnetization direction.

, M, and a vertical component perpendicular to the magnetization direction M. Then, when the horizontal component of the magnetic field is repeatedly applied to the magnetic pattern 11, the magnetizing force of the magnetic pattern 11 gradually decreases.

Therefore, in the conventional leakage magnetic field type positioner which does not consider the slope of the leakage magnetic field Hex, the linearity of the output is lost when the magnetic detection element 7 approaches the permanent magnets 2 and 3, and the output output after long-term use. There was a problem that the characteristics gradually deteriorated.

[Means for solving problems]

According to the present invention, which aims to eliminate the above-mentioned problems, one end of a pair of parallel magnetic plates 4 and 5 is attached to a magnet 2.
A positioner detects the leakage magnetic field Hex of the closed magnetic circuit 6 connected to the magnetic plate 3 with a magnetic resistance element 7 movable in the length direction of the magnetic plate 4.5, and detects the position and movement amount of the resistance element 7. is characterized in that the magnetoresistive element 7 moves substantially along opposing center lines in the opposing direction of the pair of magnetic plates 4.5, and furthermore, the magnetization direction M of the magnetic material pattern 11 of the magnetoresistive element 7, When the angle of intersection with the leakage magnetic field Hex that crosses the magnetic material pattern 11 is within 90 degrees ± 10 degrees, the magnetoresistive element 7
This is a leakage magnetic field type positioner that moves along the center line.

[Effect]

By defining the movement position of the magnetoresistive element as described above, the inclined portion of the arcuate leakage magnetic field, which has a different curvature depending on the distance from the macnet, is not applied manually to the magnetic material pattern of the magnetoresistive element.

Therefore, the linearity from the magnetoresistive element is improved, and the magnetic material pattern is not affected by demagnetization, and the performance and stability of the leakage magnetic field type positioner are improved.

〔Example〕

EMBODIMENT OF THE INVENTION Below, a leakage magnetic field type positioner according to an embodiment of the present invention will be explained using the drawings.

FIG. 1 is a plan view showing the main structure of a leakage magnetic field type physical connector according to an embodiment of the present invention, and FIG. 2 shows the direction of the leakage magnetic field of the closed magnetic circuit in FIG. 1 and the long axis of the magnetic material pattern of the magnetoresistive element. FIG.

In FIG. 1, in which the same reference numerals are used for parts common to the previous figure, a leakage magnetic field type linear positioner 21 is composed of a pair of permanent magnets (or electromagnets) 2.3 and a pair of magnetic plates (for example, 0.4 mm thick). It consists of a closed magnetic circuit 6 consisting of a steel plate 4.5, and a carrier 23 on which a magnetic detection element 7 is mounted and which moves within the closed magnetic circuit 6 in its length direction while being guided by a guide shaft 22.

The magnetic plate 4 is connected to the ONtm surface of the permanent magnet 2 and the S pole surface of the permanent magnet 3, and the magnetic plate 5 is connected to the S pole surface of the permanent magnet 2 and the S pole surface of the permanent magnet 3.
It is connected to the N-pole surface of the magnetic plates 4 and 5 and the guide 4.
i1J+22 are parallel.

As shown in FIG. 2, the magnetic material pattern 11 of the magnetic detection element 7 mounted on the carrier 23 is located on the center line CL in the opposing direction of the magnetic plates 4 and 5, and the leakage magnetic field Hex is located on the long axis 1.
2, or the leakage magnetic field He
It is configured such that the intersection angle between x and the long axis 12 does not exceed 90 degrees ± 10 degrees within the entire movement range of the gear rear 23 and moves along the center line CL.

In the first embodiment, a pair of magnetic plates 4 and 5 are connected to the magnetic pole faces of a pair of permanent magnets 2 and 3 to form a closed magnetic circuit 6. However, the present invention is not limited to the closed magnetic circuit 6 having such a configuration. It should be noted that it can be applied to a closed magnetic circuit formed by connecting magnetic plates.

〔Effect of the invention〕

As explained above, according to the present invention, the inclined portion of the arcuate leakage magnetic field whose curvature differs depending on the distance from the magnet is not input to the magnetic material pattern of the magnetoresistive element. Therefore, the linearity from the magnetoresistive element is improved, and the magnetic material pattern is not affected by demagnetization, and the performance and reliability of the leakage magnetic field type positioner are improved.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing the main structure of a positioner according to an embodiment of the present invention, FIG. 2 is a plan view showing the relationship between the leakage C branch field in FIG. 1 and the magnetic material pattern of the magnetoresistive element. Figure 3! Figure 4 is an enlarged plan view of a part of the magnetic material pattern of the magnetoresistive element; Figure 5 is a plan view showing the leakage (■ field) of Figure 3; Figure 6 is a plan view showing the relationship between the leakage magnetic field and the magnetization direction of the magnetic material pattern. In the figure, 2.3 is a permanent magnet (magnet), 4.5 is a magnetic plate, 6 is a closed magnetic circuit, 7 is a magnetoresistive element, 11 is a magnetic material pattern, 21 is a positioner 1, M is a magnetization direction, and 11ex is a leakage magnetic field. , Expanded version of the 3 hiki five sister worlds and the 700 yakuroki resistance quenches in figure 1.

Claims (2)

[Claims] (1) The leakage magnetic field (Hex) of a closed magnetic circuit (6) in which one end of a pair of opposing magnetic plates (4, 5) is connected to the magnet (2, 3) is transferred to the magnetic plates (4, 5). is detected by a magnetic resistance element (7) movable in the length direction of the resistance element (7).
), the leakage magnetic field type positioner is characterized in that the magnetoresistive element (7) moves approximately along the center line of the pair of magnetic plates (4, 5) in opposing directions. positioner. (2) Magnetic material pattern (11) of the magnetoresistive element (7)
) and the magnetic leakage field (Hex) that crosses the magnetic material pattern (11) is 90 degrees ± 1.
The leakage magnetic field type positioner according to claim 1, characterized in that the magnetoresistive element (7) moves along the center line within 0 degrees.