JPH0662315U - Automatic vertical magnetic braking system - Google Patents

Abstract

(57) [Abstract] [Purpose] Improving the braking performance by making the braking force for braking the swing of the pendulum always constant regardless of the position of the brake plate at the lower end of the pendulum [Configuration] Pendulum The braking plate 13 at the lower end of 3 is curved in an arc shape with a radius R1 centered on the swing fulcrum of the pendulum, and the braking magnets 14 and 15 have a radius R2 larger than the radius R1 centered on the swing fulcrum. Place on the arc line of.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a magnetic braking device for braking swing of a pendulum by magnetic force in an automatic vertical device that projects a light beam such as a laser beam from a pendulum.

[0002]

[Prior art]

 The automatic vertical device is equipped with an automatic correction mechanism that keeps the pendulum in the vertical state in order to automatically correct the projected light beam such as laser beam to make one optical vertical line. . Further, in order to effectively perform the correction, the swing of the pendulum is controlled by a braking device.

1 and 2 show a conventional automatic vertical device of this type. In this automatic vertical device, a cylindrical pendulum 3 is suspended by a gimbal mechanism 4 on an upper plate 2 of a pedestal 1 so as to be swingable. A light projecting system 5 for projecting a laser beam is provided in the pendulum 3. The gimbal mechanism 4 supports the ring 7 on the pair of bearings 6 on the upper plate 2 so as to be swingable in the X direction by the first shaft 8, and the upper end portion of the pendulum 3 is attached to the ring 7 at the first position. The shaft 8 is rotatably supported in the Y direction by a shaft 9 whose axis is perpendicular to the shaft 8. Even if the pedestal 1 vibrates, the pendulum 3 is always kept vertically by gravity.

A braking plate 10 made of metal such as copper or silver is fixed to the lower end of the pendulum 3, and two sets of braking magnets 12 in the X direction and two sets in the Y direction are mounted on the base 11 of the pedestal 1. And the braking magnet 13 of FIG. The braking plate 10 is a simple flat disc whose upper and lower surfaces are parallel to each other, and the braking magnets 12 and 13 are located on the same horizontal plane.

When the braking plate 10 moves, the lines of magnetic force of the braking magnets 12 and 13 are cut, so that an eddy current is locally generated in the braking plate 10, and the braking force in the direction opposite to the movement direction of the braking plate 10 is generated. Works. This braking force F is generally represented by F = K (dφ) / R (dt). Here, K is a proportional constant, R is an electric resistance, and the braking force F is proportional to the rate of change (dφ) of the magnetic flux per unit time (dt).

[0006]

[Problems to be solved by the device]

 However, this is a condition when the braking plate 10 moves in parallel with the magnets 12 and 13, and in the above-described conventional structure, as shown in FIG. Since not only parallel motion but also vertical motion is applied, the distance between the magnets in the same direction and the braking plate 10 is different, and a difference (unbalance) in braking force occurs at points a and b. However, there was a problem that the braking performance was not good.

An object of the present invention is to improve the braking performance by keeping the braking force between the braking plate and the magnet constant at any position of the braking plate.

[0008]

[Means for Solving the Problems]

 In the magnetic braking device according to the present invention, the braking plate at the lower end of the pendulum is curved in an arc shape having a radius R1 with the swing fulcrum of the pendulum as the center, and the braking magnet has a radius with the swing fulcrum as the center. It is arranged on an arc line having a radius R2 larger than R1.

[0009]

[Action]

 Therefore, no matter where the braking plate swings, the distance between it and the magnet is always constant, and the braking force does not become unbalanced.

[0010]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 4 shows an automatic vertical device to which the present invention is applied. In this automatic vertical device, a cylindrical pendulum 3 is suspended by a gimbal mechanism 4 on an upper plate 2 of a pedestal 1 in the same manner as that shown in FIG. The magnetic braking device including the braking plate 13 and the braking magnets 14 and 15 in the X and Y directions arranged on the base 11 of the gantry 1 has the following configuration.

The braking plate 13 has a spherical shape (a bowl shape) with a radius R1 around the swing fulcrum O of the pendulum 3, and the braking magnets 14 and 15 both have a radius around the swing fulcrum O. They are arranged on the arc line of R2 (R1> R2), and their magnetized surfaces are fixed on the base 11 so as to be perpendicular to the swing fulcrum O.

Therefore, in both swinging of the pendulum 3 in the X and Y directions, the distance between the lower surface of the brake plate 13 and the brake magnets 14 and 15 is always constant, and the swing position of the brake plate 13 is constant. Regardless of, the braking force is always constant.

It should be noted that the braking plate 13 is not limited to the spherical shape, but two such members as shown in FIG. 7, that is, two lengths in the X direction and the Y direction which are curved along an arc centered on the swing fulcrum O are provided. It may be constituted by the plates 13a and 13b, or may be constituted by one long plate 13a which is curved only in one direction as shown in FIG.

[0014]

[Effect of device]

 As described above, according to the magnetic braking device of the present invention, the braking plate at the lower end of the pendulum is curved in an arc shape with a radius R1 centered on the swing fulcrum of the pendulum, and the braking magnet is larger than the radius R1. Since it is placed on the arc line of radius R2, no matter which position the braking plate swings, the distance between it and the magnet is always constant, and the braking force does not become an imbalance due to the swinging of the braking plate. Can be improved over the conventional one.

[Brief description of drawings]

FIG. 1 is a perspective view of a conventional automatic vertical device.

FIG. 2 is a sectional view of the same.

FIG. 3 is an operation explanatory view showing that the braking force is unbalanced in the magnetic braking device of the automatic vertical device.

FIG. 4 is a perspective view of an automatic vertical device including a magnetic braking device according to the present invention.

FIG. 5 is an operation explanatory view of the magnetic braking device.

FIG. 6 is a perspective view of a braking plate in the magnetic braking device.

FIG. 7 is a perspective view of another example of the braking plate.

FIG. 8 is a perspective view of still another example of the braking plate.

[Explanation of symbols]

 1 mount 3 pendulum 4 gimbal mechanism 13 braking plate 14 ・ 15 magnet

Claims (1)

[Scope of utility model registration request] 1. A pendulum having a built-in light projecting system for projecting a light beam such as a laser beam is suspended by a gimbal mechanism so as to be swingable, and a metal braking plate is provided at the lower end of the pendulum. In a magnetic braking device for an automatic vertical device in which a braking magnet is arranged on a base, the braking plate is curved in an arc shape having a radius R1 around a swing fulcrum of the pendulum, and the braking magnet is the same. A magnetic braking device for an automatic vertical device, wherein the magnetic braking device is arranged on an arc line having a radius R2 larger than a radius R1 centered on a swing fulcrum.