JPH0240989B2 - KADOJISHAKUGATAKEIKINOSEIZOHOHO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a movable magnet type instrument to be installed on vehicles, ships, and other equipment.

(Prior art) A movable magnet type instrument has a magnetic plate connected to a pointer shaft placed inside a fixed coil wound in a crossed manner, and a current corresponding to the detected amount is applied to each fixed coil connected to an external signal line. By flowing the current, the movable magnet rotates in angle due to the composite magnetic field of the crossed coils, and the pointer is operated (Utility Model Application No. 55-34240,
59-116861).

The movable magnet type instrument has a movable magnet enclosed in a bobbin formed by upper and lower frames made of resin with mounting legs provided at the four corners, and a pointer shaft that protrudes outside the frame so that it can be rotated as desired. A crossed coil is wound around the outer surface of the frame, and a pointer is attached in a predetermined direction. However, since the attachment of the pointer affects the index performance of the instrument, and the internal magnet rotates arbitrarily, the conventional attachment of the pointer is as shown in the circuit shown in Figure 4, with respect to instrument A. Apply electricity in the same manner as in the mounted state, change the resistance value of the substitute resistor B of the unit to be measured to a predetermined value, move the internal magnet in response to the current change, and hold the pointer in a stable position. It is designed to be attached to the pointer shaft.

(Problems to be Solved by the Invention) In the conventional pointer attachment means described above, for example, when damper oil is put in the bobbin containing the magnet to suppress unnecessary swinging of the pointer, the energization It takes a long time for the internal movable magnet to become stable (for example, it takes about 150 seconds to check at least three stable positions until one point becomes stable), which is very inefficient. Also, due to the relationship between meter torque and hysteresis, the stable position of the internal movable magnet is different when the current flowing through the crossover coil increases and when it decreases, and the variation is large, making it difficult to obtain uniform quality. , which is one of the causes of an increase in the defective rate.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention improves the conventional method in manufacturing pointer instruments in which a movable magnet that rotates around a pointer shaft is provided in a fixed coil. Rather than attaching a pointer shaft after a movable magnet is installed in a crossed coil, an unmagnetized magnetic material is installed in the crossed coil in advance, and the magnetic material is attached at a predetermined angle from the pointer when or after the pointer is attached. It is designed to be magnetized.

Therefore, it is manufactured so that the direction in which the pointer is attached and the direction of magnetization of the internal movable magnet are always in a constant relationship, and there is no need to apply electricity to find the stable position of the internal movable magnet as in the past. It is something that has become familiar.

(Example) Next, an example of the present invention will be described based on the drawings.

Fig. 1 is a partially cutaway front view of a meter manufactured by the method of the present invention, Fig. 2 shows an example of a magnetizing device during magnetization, and Fig. 3 is a plan view thereof.

As shown in Fig. 1, a movable magnet type pointer gauge generally has upper and lower frames 2 with mounting legs 1 provided at the four corners combined to form a bobbin 3. A movable magnet 4 is installed inside the frame, and a crossed coil 5 is wound around the outer surface of the frame.
Separately, a pointer shaft 6 is connected to a movable magnet 4, the pointer shaft 6 is made to protrude from the upper frame 2, and a pointer 7 is attached to the pointer shaft 6.

In manufacturing the movable magnet type instrument of the present invention, a non-magnetized magnetic material is housed in the bobbin 3, and after winding the crossed coil 5 around the frames 2 and 2', the second As shown in the figure, the pointer 7 is placed between the magnetism generators a at a predetermined angle θ with respect to the magnetization direction.
At the same time, a strong magnetic field from a magnetic generator a is applied to magnetize the internal magnetic material to form a movable magnet 4. Of course, the pointer 7 should be connected to the pointer shaft 6 in advance.
The internal magnetic body may be magnetized after the pointer 7 is placed at a predetermined angle θ when placed between the magnetic generators a.

Therefore, the relationship between the mounting direction of the pointer 7 and the magnetization direction of the internal movable magnet 4 is always constant, making it possible to supply instruments with good index accuracy and uniform quality, and to significantly reduce the defective rate. Even when damper oil is used, the stabilization time required in the conventional method is not required, so that the production thereof can be carried out efficiently.

(Effects of the Invention) As described above, in manufacturing a movable magnet type meter, the present invention incorporates a magnetic body into the meter without incorporating a magnet piece into the meter, and magnetizes the internal magnetic body when or after the pointer is attached. It is designed to be a movable magnet, and since there is no need for the conventional adjustment when attaching the pointer, the manufacturing efficiency is improved, the quality is also excellent, and the defective rate is drastically reduced.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Fig. 1 is a partially cutaway front view of the meter body, Fig. 2 is a front view of the instrument in a magnetized state, Fig. 3 is a plan view of the same, and Fig. 4 is a conventional FIG. 3 is a circuit diagram showing an adjustment method. 1 is a mounting leg, 2, 2' is a frame, 3 is a bobbin, 4 is a movable magnet, 5 is a crossed coil, 6 is a pointer shaft, and 7 is a pointer.

Claims (1)

[Claims] 1. When manufacturing a pointer instrument in which a movable magnet that rotates around a pointer shaft is installed in a fixed coil, an unmagnetized magnetic material is placed inside the fixed coil in advance, and when the pointer is attached or after the pointer is attached, A method for manufacturing a movable magnet type instrument, characterized by magnetizing a magnetic body at a predetermined angle with a pointer.