JPH0738862Y2 - Cross coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a cross coil formed by winding a pair of coils used in a cross coil type indicator and the like so as to cross each other.

[Conventional technology]

A cross-coil type indicating instrument is generally a permanent coil in a magnetic field generated by an air-core cross-coil which is formed by winding first and second coils L ₁ and L ₂ so as to intersect each other at substantially right angles as shown in FIG. A rotatable magnet rotor M composed of a magnet is arranged. A pointer A is attached to the magnet rotor M.

In this arrangement, proportional to the product of the first, second coil L _1, a magnetic field [Phi ₁ where L ₂ is generated, [Phi ₂ is current and number of turns, each flowing in coil L _1, L _2. This and the coils L _1, L ₂ are both turns N, each I ₀ sin [theta current flowing, when I ₀ cos [theta], the combined magnetic field [Phi magnetic field [Phi ₁ each coil L _1, L ₂ is generated, the [Phi ₂ This is the direction of the composite vector, and the composite magnetic field draws a circle according to the angle θ. Therefore, by making the angle θ correspond to a predetermined measurement amount, the respective magnetic fields Φ ₁ and Φ _{2 become} Φ ₁ = I ₀ sin θ · N (1) Φ ₂ = I ₀ cos θ · N (2) , The synthetic magnetic field Φ is generated in the direction in which the magnetic fields Φ ₁ and Φ ₂ are vector-synthesized, and its magnitude is Therefore, by changing the angle θ according to the predetermined measurement amount as shown in FIG. 4, the direction of the synthetic magnetic field Φ corresponds to the predetermined measurement amount. Therefore, the magnet rotor M rotates in the direction of the composite magnetic field, and the pointer A also rotates in cooperation with the pointer A, so that the pointer A indicates a predetermined measurement amount at the rotation angle position, and this can be recognized. .

The conventional cross coil L is, as shown in FIG.
Coil L ₁ of a predetermined number of turns and then the second coil L ₂
Is wound on the outside of the first coil L _{1 by} a predetermined number of turns so as to intersect with each other by 90 °.

[Problems to be solved by the device]

In the above-described conventional cross coil, the first coil L ₁ wound inside as shown in FIG. 5 and the second coil L ₂ wound outside thereof have different outer diameters, so that the same number of turns is used. If so, the total length of the coil is longer in the outer second coil L ₂ .
Therefore, when the resistance value per unit length of each coil is equal, the resistance value of the second coil L ₂ is larger than that of the first coil L _1, and the resistance values of both are equal. When wound, the number of turns of the outer second coil L ₂ is equal to that of the first coil L ₁
Less than.

On the other hand, the magnitudes of the magnetic fields Φ ₁ and Φ ₂ of each coil are (1),
It is proportional to the product of the current flowing through the coil and the number of turns as shown in equation (2). Therefore, in the conventional cross coil, the maximum magnetic field I ₀ · N of each coil L ₁ and L ₂ generated according to the predetermined measurement amount (angle θ)
It is difficult to make them identical. That is, each coil
When the same voltage is applied to L ₁ and L ₂ , the magnetic fields Φ ₁ and Φ ₂ are not equal because the currents flowing through them are different.

For example, when the number of turns N of both coils is made equal, the resistance value of the outer second coil L ₂ becomes large as described above, so that the currents I ₀ in the equations (1) and (2) are not equal. ,
The current in the _first coil L ₁ is larger than that in the second coil L ₂ . When the currents of the coils are I ₁ and I ₂ , respectively, the magnetic fields Φ ₁ and Φ ₂ are Φ ₁ = I ₁ sin θ · N (4) Φ ₂ = I ₂ cos θ · N (5) I ₁ > I ₂ . Therefore, the magnitude of the synthetic magnetic field Φ is Therefore, as shown in FIG. 6, only a circular characteristic is obtained according to the angle θ.

For example, when a current having an angle θ of 45 ° according to a predetermined measurement amount is applied to such a cross coil, the magnetic fields Φ ₁ and Φ ₂ of the coils L ₁ and L ₂ are expressed by equations (4) and (5). Than And the angle α of the composite magnetic field Φ becomes α = tan ⁻¹ (Φ ₁ / Φ ₂ ) = tan ⁻¹ (I ₁ / I ₂ ) ≠ 45 ° (9), and the predetermined measurement to be instructed Angle according to quantity (45
°) does not match. Therefore, in the conventional cross coil, the direction of the combined magnetic field of the cross coil does not coincide with the direction of the angle θ corresponding to the predetermined measurement amount, so that the predetermined measurement amount cannot be accurately indicated.

Therefore, in view of the above points, the present invention has an object to provide a cross coil in which, when the same voltage is applied to the cross coils, the magnitudes of the magnetic fields generated by the coils are equal.

[Means for Solving the Problems]

To achieve the above object, a cross coil according to the present invention is a cross coil formed by winding a pair of coils so as to cross each other, and each coil wound in one layer at a portion not crossing each other. The windings for each unit number of the windings are wound so that the windings of the other coil are alternately overlapped with each other at the intersecting portions.

[Action]

In the above configuration, when the windings forming each of the pair of coils are wound by one layer in the portions that do not intersect with each other, the windings of the other coil are wound for each unit winding number in the portions that intersect with each other. Since the coils are wound so that they are turned upside down and overlap each other, when the same number of coils are wound, the total lengths of both coils are equal to each other, and therefore the resistances of both coils are equal. As a result, if the same voltage is applied to each coil, the currents flowing through both coils become equal and the magnitudes of their magnetic fields also become equal.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, the first and second coils L ₁ and L ₂ of the cross coil L are alternately wound every unit winding number (for example, one winding). That is, when the first coil L ₁ is wound once, the second coil L ₂ is then wound on the first coil L ₁ once. Further, the first coil L ₁ is crossed and wound once thereon. Repeat this winding operation for each coil the same number of times,
Use the same number of turns. As a result, the two coils L ₁ and L ₂ are wound in one layer in the portions that do not intersect with each other, but in the portions that intersect with each other, the coils are turned upside down for each unit winding number as shown in FIG. Are overlapped with each other. Therefore, since the total lengths of the first and second coils L ₁ and L ₂ are equal and their resistance values are also equal, the magnitudes of the magnetic fields Φ ₁ and Φ ₂ generated when the same voltage is applied to each coil. Are also equal to each other.

When the above-described cross coil according to the present invention is applied to a cross coil type indicator, the currents I ₀ can be equalized and the magnitudes of the magnetic fields Φ ₁ and Φ ₂ can be equalized as in the equations (1) and (2). Therefore, as shown in FIG. 4, the composite magnetic field Φ has a circular characteristic according to the angle θ. Therefore, if the angle θ is changed in accordance with the predetermined measurement amount, the direction of the synthetic magnetic field Φ accurately corresponds to the angle θ, that is, the predetermined measurement amount, and the magnet rotor M and the pointer A accurately determine the angle θ. The measurement amount can be specified.

〔effect〕

As described above, according to the present invention, when the same voltage is applied to each coil of the cross coil, it is possible to generate a magnetic field of the same magnitude. For example, when applied to an indicating instrument, the indicated angle is a predetermined measurement. It is possible to accurately correspond to the amount and prevent the occurrence of an indication error.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a cross coil according to the present invention, FIG. 2 is an enlarged view of an essential part of FIG. 1, and FIG. 3 is a view showing a cross coil type indicator to which the present invention is applied, FIG. 4 is a diagram showing characteristics of a synthetic magnetic field generated by the cross coil according to the present invention in the FIG. 3 indicating instrument, FIG. 5 is a sectional view showing a conventional cross coil, and FIG. 6 is an indicating instrument of FIG. FIG. 6 is a diagram showing characteristics of a synthetic magnetic field generated from the cross coil of FIG. L: cross coil, L _1: first coil, L _2: second
Coil, M ... Magnet rotor, A ... Pointer.

Claims (1)

[Scope of utility model registration request] 1. A cross coil formed by winding a pair of coils so as to intersect with each other, and for each unit winding number of windings of each coil wound in one layer in a portion not intersecting each other. The cross coil is characterized in that the winding of the coil is wound so as to overlap with the winding of the other coil alternately at the intersecting portions.