JPS5911850B2 - Pendulum for vibration detection - Google Patents

Description

[Detailed description of the invention] The present invention relates to a pendulum for vibration detection.

An example of a conventional vibration detection pendulum will be explained with reference to FIG. 1. Reference numerals 1a and 1b are leaf springs, and both leaf springs la and 1b have an annular inner circumferential portion 2 and an annular outer circumferential portion 3 as shown in FIG. It consists of an arcuate spring part 4 provided in the middle, and these parts are integrally formed from the same plate material.

5 is a bobbin, 6 is a coil wound around the bobbin 5, 7 to 9
10 is a leaf spring holding plate, 10 is a connecting rod, 11a and 11b are lids, 12 is a yoke, 13 is a permanent magnet, 14 is a pole piece, 15 is a shaft screw, 16a and 16b are coil lead wires,
17a and 17b are terminals.

The inner circumferential portion 2 of the leaf spring 1a includes a bobbin 5 and a leaf spring holding plate 7.
The inner periphery of another leaf spring 1b is sandwiched between leaf spring retaining plates 8 and 9 and fixed by connecting rods 10, respectively.

The outer periphery 3 of the plate springs 1a, lb is the lid body 11a, 11.
b and the yoke 12, and the shaft screws 15 passed through the inside of the connecting rod 10 connect the two differential bodies 11a.

It is fixed by connecting the yoke 11b and the yoke 12.

Here, a bobbin 5 supported by leaf springs la and lb,
The coil 6, the leaf spring press plates 7 to 9, and the connecting rod 10 constitute a pendulum mass.

The permanent magnet 13 and the pole piece 14 are adhesively fixed on the same axis of the cylinder of the yoke 12.

When the leaf springs Ia and 1b are assembled as described above,
The gravity applied by the pendulum mass and the restoring force of the spring are balanced, and the inner circumferential portion 2, outer circumferential portion 3, and arcuate spring portion 4 become substantially flat, so that the pendulum mass does not hit the lids 11a and 11b. ing.

That is, before assembly, the leaf springs Ia and 1b are formed in advance in a crown shape so that the inner peripheral part 2 is higher than the outer peripheral part 3, and when supporting the pendulum mass, they are flat and parallel to each other. It is assembled so that.

To explain the operation here, when vibration is applied, the pendulum mass moves relative to other parts, and the coil 6, which is a part of the pendulum mass, moves between the yoke 12 and the pole piece 1.
4, cut the magnetic flux in the gap between the coil lead wire 16a
, 16b to the terminals 17a, 17b.

The position of the pendulum mass in the vibration detection pendulum explained above depends exclusively on the size of the pendulum mass and the crown-shaped plate spring Ia.
Although it depends on the initial height of , lb, the position of the pendulum mass is conventionally determined by finely adjusting the pendulum mass by cutting, etc., or by selecting one with suitable characteristics from among carefully manufactured leaf springs. Because of this adjustment, a large number of man-hours are required for assembly adjustment, inspection and selection of the leaf springs, and the yield of the leaf springs is also low.

The present invention is characterized in that the position of the pendulum mass can be easily adjusted by arranging both leaf springs nonparallelly so that they exert forces on each other.The purpose of this invention is to easily adjust the position of the pendulum mass. An object of the present invention is to obtain a vibration detection pendulum that can significantly reduce the number of man-hours and improve the yield of leaf springs.

An embodiment of the present invention will be described with reference to FIGS. 3 and 4.

Figures 3a, b, and c show the relative positions of the leaf springs 1a and 1b before supporting the pendulum mass in the present invention, and the arcuate spring portions 4 of both leaf springs 1a and 1b are parallel to each other. be.

Figure 4 atbyc is a leaf spring 1 supporting a pendulum mass.
The relative positions of a and 1b are shown, and both leaf springs 1a and 1
The arcuate spring portions 4 of b are arranged non-parallel to each other.

In order to install and arrange the leaf springs 1a and 1b in this manner, the dimensions of one or both of the connecting rod 10 and the yoke 12 shown in FIG. 1 may be set in advance so that they are non-parallel.

In Figures 3 and 4, (a) shows when the pendulum mass is located at the top, (b) shows when the pendulum mass is located at the neutral point, and (
c) shows the case where it is located at the bottom.

If the arcuate spring portions 4 of the leaf springs 1a and 1b are parallel to each other as shown in FIG. 3, the leaf springs Ia and lb only have the function of supporting the pendulum mass and guiding the pendulum mass in the direction of the operating axis. No other forces act on it, and the position of the pendulum mass remains almost constant no matter how it is assembled.

However, when the arcuate spring portions 4 are installed so as not to be parallel to each other as shown in FIG. The power of will arise.

This force is related to the position of the pendulum mass and both leaf springs 1a, 1b
The relative position of the pendulum changes slightly depending on whether the relative position is set to one of the states a, b, or c in Figure 4 and the shaft screw 15 is tightened, which is the final step during assembly.Use this to adjust the pendulum mass. The position can be adjusted.

In this embodiment, when the shaft screw 15 is tightened in the state shown in FIG. will be located in

In the case of a vibration detection pendulum that has a magnetic circuit and a coil as shown in Fig. 1, the position of the pendulum mass when tightening the shaft screw 15 can be adjusted by using the electromagnetic force generated when direct current is passed through the coil. You can also do it.

In this embodiment, a pendulum for detecting vibrations in the vertical component is illustrated and explained, but it can also be used as a pendulum for detecting vibrations in the horizontal component.

Further, the shapes of the leaf springs 1a and Ib are not limited to the shapes shown in the drawings, but may be other suitable shapes.

As explained above, in the present invention, since the two leaf springs supporting the pendulum mass are arranged non-parallel to each other,
It is now possible to adjust the position of the pendulum mass with a single shaft screw without having to adjust the pendulum mass or select a compatible leaf spring, greatly reducing the number of man-hours required for assembly adjustments and leaf spring characteristic inspections. This makes it possible to improve the yield of leaf springs.

゛ Also, since the position of the pendulum mass can be adjusted, if the spring characteristics of the leaf spring have non-linearity depending on the position within the allowable range for operational performance, the natural frequency of the pendulum can be changed by adjusting the position of the pendulum mass. It is possible to have the function of obtaining

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a conventional vibration detection pendulum, Fig. 2 is a plan view showing the shape of a leaf spring, and Fig. 3 shows the relative position of the leaf spring before supporting the pendulum mass in the present invention. 4 is a cross-sectional view showing the relative positions of the leaf springs while supporting the pendulum mass. 1a, 1b...Plate spring, 2...Inner peripheral part, 3...Outer peripheral part, 4...Circular spring part, 5...Bobbin, 6...
- Coil, 7 to 9... Leaf spring holding plate, 10... Connecting rod, 11a. 11b...Lid body, 12...-Yoke, 13...Permanent magnet, 14...Pole piece, 15...Shaft screw.

Claims (1)

[Claims] 1. An arcuate spring portion is formed between the inner circumferential portion and the outer circumferential portion.2
In a vibration detection pendulum in which two leaf springs are arranged to face each other on a motion axis and a pendulum mass is supported by both leaf springs, the relative distance on the motion axis between the fixed parts of the two leaf springs. A pendulum for vibration detection, characterized in that the relative position of the pendulum mass to the support side or the natural frequency of the pendulum can be adjusted by making the pendulum side and the support side different by a very small amount. 2. Claim 1, characterized in that the relative positions of both leaf springs are arranged non-parallelly so that when one leaf spring is in a flat state, the other leaf spring is in a bent state. The vibration detection pendulum described. 3. The vibration detection pendulum according to claim 1, wherein the relative positions of both leaf springs are non-parallel so that they are bent relative to each other.