JPS6032326B2 - release type magnetic circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic circuit of a polarized release type relay used in a shutter magnet type earth leakage breaker of a camera, etc.

In the polar release type ljray, a fixed piece of magnetic material and a movable iron piece are attracted by the magnetic flux of a permanent magnet, and when an operating current flows through the sheet-reading coil wound on this fixed piece, the magnetic flux generated from the coil is generated. The magnetic flux generated by the permanent magnet acts in the direction of weakening the magnetic flux generated by the permanent magnet, thereby weakening the attraction force between the fixed piece and the movable iron piece.

The movable piece of iron is moved by the action of a spring connected to it.
It separates from the fixed piece, and at this time the shutter of the camera is activated. The movable iron piece is separated from the fixed piece until it returns to its original position.
A release type magnetic circuit is usually constructed by arranging a pair of fixed pieces facing each other. The current sensitivity can also be affected by factors such as temperature, and miniaturization is required especially when used in camera shutters, etc., so recently a system in which the magnetic pole of the fixed piece is made of one piece has been realized. .

However, in this type of release type magnetic circuit currently in use, the volume of the permanent magnet is changed (that is, the permanent magnets being held are replaced) in order to adjust the attraction force of the movable iron piece by the permanent magnet. The disadvantage is that the adjustment is done in stages, so it is not always possible to set it to the optimal condition, and it is used when troubles occur such as foreign matter adhering to the suction surface, friction, or aging. There are drawbacks that make it impossible.

SUMMARY OF THE INVENTION An object of the present invention is to improve the above-mentioned drawbacks and provide a polarized open-circuit magnetic circuit with a constant sensitivity current and high reliability.

In order to achieve the above object, the present invention is characterized in that a defective portion is provided in a part of the magnetic circuit so as to achieve magnetic saturation, and a movable magnetic flux adjustment piece is provided in the defective portion to bypass the magnetic flux.

FIG. 1 is a diagram illustrating the principle structure of the present invention, FIG. 2 is a back view of the center of the fixed piece missing portion, and FIG. 3 is a cross-sectional view taken along the line AA in FIG. 2. In the figure, 1' is a fixed piece having a missing portion 2, and 3 is a yoke. A permanent magnet 4 is held between the fixed piece 1 and the yoke 3, and of the magnetic flux from the permanent magnet 4, the magnetic flux passing through as shown by broken lines 5 and 5' is magnetically saturated due to the presence of the defective portion 2. Therefore, most of the magnetic flux from the permanent magnet 4 flows as shown by the broken line 6, causing the movable piece 8 to be attracted to the magnetic pole surfaces 7, 7'. In this state, the coil 9 is energized,
By generating a magnetic field in the opposite direction to the magnetic flux 6 to cancel the magnetic flux 6, the movable piece 8 is separated from the magnetic pole faces 7, 7' by the force of a spring or the like (not shown). By the way, in the above configuration, due to variations in the finish of the contact surfaces between the magnetic pole surfaces 7, 7' and the movable piece 8, variations in the tensile force of the spring etc. that separates the movable piece 8, variations in the characteristics of the permanent magnets, etc. Since the adsorption force of the movable piece fluctuates, this must be prevented. Therefore, in the present invention, a magnetic flux adjusting piece 10 made of a magnetic material that is slightly larger than the defective part 2 is provided in the vicinity of the defective part, and by moving the adjusting piece 10 in and out in the direction of the arrow 11, the broken line 5, If the amount of magnetic flux passing through is adjusted as shown by 5' and the required amount of characteristics is obtained on the magnetic pole surfaces 7 and 7', the magnetic flux adjustment piece 10 is a magnetic material, so the magnetic flux is adjusted as shown by broken lines 5 and 5'. Since the fixing piece 1 is attracted by the circuit, it is sufficient to simply hold the magnetic flux adjusting piece 10 lightly by the side surface or the back surface. Further, in the present invention, the defective portion is not limited to a hole, but may have any shape as long as the defective portion is configured to be magnetically saturated. The present invention will be explained in detail below with reference to Examples.

On the middle 2.5 sides of both legs, on the middle 5 ribs of the central part, there is a U-shaped permalloy with a thickness of 1 side.
．． The hole on the 5th side) was raised to create a fixing piece.

The yoke is an L-shaped permalloy with arms on the middle 2.5 side and middle 5 ribs, and the arms on the middle 2.5 ribs and one leg of the fixed piece (2.5 A permanent magnet with a size of 3.3 fences x 3.3 ribs x 0.4 sides is held between the arms of the 5 skins in the yoke and the center part of the fixed piece (in the 5 skins). did. This permanent magnet has a residual magnetic flux density of 8.
Rare earth cobalt permanent magnets with a gunwale G, a coercive force of 7,500 yen, and a magnetic energy handling ratio of G/ratio were used. When a permalloy material with 4 sides, 5 legs in length, and 1 skin in thickness was used as the magnetic flux adjustment piece, and the above hole was completely bypassed, the adsorption force of the movable piece was 10.
09, which can reduce the adsorption force by 400 when the adjustment piece is fully opened, and by further adjusting the setting position of the magnetic flux adjustment piece in the direction of the arrow, it becomes 10.
It was found that the adsorption force can be easily set to any value between 0 and 400 hours. Moreover, even if this adsorption force was changed, there was almost no effect on the release current. As described in detail above, the present invention makes it possible to easily adjust the suction force without impairing the features of the integral fixing piece, making it possible to realize a highly accurate and highly reliable release type relay. It is extremely useful for magnetic circuits that exchange electrical energy into mechanical energy, such as for machine shutters and magnetic earth leakage breakers.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the principle structure of the present invention, FIG. 2 is a back view of the center of the fixed piece missing portion, and FIG. 3 is a sectional view taken along line AA in FIG. 2. 1: Fixed piece, 2: Missing part, 3: Yoke, 4: Permanent magnet,
8: Movable piece, 9: Coil, 10: Magnetic flux adjustment piece. Tsutomu drawing 2nd sardine drawing 3rd

Claims (1)

[Claims] 1. A movable piece, a fixed piece that has a surface that attracts the movable piece and has a defective part so that a portion of the movable piece is magnetically saturated, a yoke that brings the fixed piece and the part into close contact, and In a magnetic circuit in which a permanent magnet is disposed so as to be on the other side of the defective portion, and the permanent magnet is held between the fixed piece and the yoke, a magnetic flux for adjusting the amount of leakage magnetic flux in the defective portion is provided. A release type magnetic circuit characterized in that an adjustment piece is provided near the defective portion.