JPH0240990B2 - KADOJISHAKUGATAKEIKINOSEIZOHOHO - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is used in the manufacture of movable magnet type instruments installed in vehicles, ships, and other equipment, particularly in the manufacture of improved methods for attaching a pointer to a pointer shaft. It is about the method.

(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. When the current flows, 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 with mounting legs provided at the four corners, and a pointer shaft that protrudes outside the frame so that it can be rotated arbitrarily. A crossed coil is wound on the outer surface, 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 based on 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, it takes a long time from energization until the internal movable magnet stabilizes (for example, it takes at least 3 seconds to stabilize one point in about 150 seconds). (checking the stable position of a point) 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 increase in defective rate.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a method for manufacturing pointer instruments in which a movable magnet that rotates around a pointer shaft is provided in a fixed coil. A gauge is positioned between the needles, and the pointer is attached to the pointer shaft in a predetermined direction while the internal magnet is attracted and held in a predetermined direction.

Therefore, the pointer can be reliably mounted at a position offset by a predetermined angle Θ from the magnetization direction of the internal movable magnet without energizing the meter, and variations in the pointer mounting position will not occur.

(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 pointer attachment mechanism during magnetization, and FIG. 3 is a plan view thereof.

As shown in FIG. 1, a movable magnet type pointer instrument generally has upper and lower frames 2, 2' having mounting legs 1 at their four corners combined to form a bobbin 3.
A movable magnet 4 that can be freely rotated is installed inside the bobbin 3, and a crossed coil 5 is wound around the outer surface of the frame. The pointer 7 is mounted on the pointer shaft 6 so as to protrude.

The present invention relates to the pointer mounting process which is the final stage in the manufacture of the movable magnet type instrument, and when the instrument body without the pointer 7 is placed between the external magnets a, the internal movable magnet 4 is attached to the external magnet. It is attracted and held in its own magnetization direction by the magnetic force of a. In this state, the pointer 7 is attached to the pointer shaft 6 at a predetermined angle Θ.

Therefore, the stronger the magnetism from the external magnet, the faster the internal magnet stabilizes (for example, the time for the 150-second instrument mentioned above was reduced to about 6 seconds), and the more stable it becomes, even if the external magnet is sufficiently strong. By appropriately selecting the external magnet, the pointer shaft 7 can be mounted at a constant angle to the magnetization direction of the internal movable magnet 4 without impairing performance.

(Effects of the Invention) As described above, in manufacturing a movable magnet type instrument, when a pointer is attached to a pointer shaft, the instrument body is positioned between external magnets to stabilize the internal movable magnet in the magnetization direction. It was designed to be installed after
Compared to conventional energization methods, the internal movable magnet is stabilized in a predetermined position quickly, so manufacturing efficiency is improved, there is no variation in the pointer attachment angle, and the defective rate is drastically reduced.

[Brief explanation of drawings]

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 pointer gauges that have a movable magnet that rotates around a pointer shaft in a fixed coil, the gauge is positioned between the outer magnets and the inner magnet is attracted and held in a predetermined direction. A method for manufacturing a movable magnet type instrument, characterized in that a pointer is attached to a pointer shaft at a predetermined angle direction.