JPS5850479Y2 - Ionization smoke detector radiation source fixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radiation source fixing device for an ionization smoke detector, and an object thereof is to provide a radiation source fixing device that can securely attach the radiation source and the electrode.

Conventionally, in an ionization type smoke detector, the radiation source was fixed to the electrode plate using cut-and-raised pieces 1a, 1 for stopping at both ends, as shown in Fig. 1.
a and a cut and raised piece 1b for fixing the intermediate part.

1b... is formed on the electrode 2, the radiation source 3 is installed between the pieces 1a and Ia with both ends cut and raised, and the middle part is cut and raised between the pieces 1b and 1b.
It was held in place by pressing it down.

Such a fixing device has the disadvantage that it cannot securely fix the radiation source if it has long or short lengths.

In other words, if the radiation source is too long, cut and raise the pieces la on both ends,
1a, and if it is too short, the intermediate cut and raised pieces 1b, 1b will not be sufficient to fix it, and it will move in the axial direction, causing the radiation source position to shift.

The present invention was developed in view of these reasons.

The embodiment of the radiation source fixing device of the present invention will be described below with reference to FIGS. 2 to 4, in which the same parts as those in the conventional example are given the same reference numerals. 4, and a radiation source 30 is placed on the bottom side of the electrode in the through hole 4.
A recess 5 into which both ends fit is formed.

6 is a fixing plate having a protrusion 7 formed in its center.

This protrusion 7 is sized to fit into the through hole 4.

When the radiation source 3 is in a fixed state, the fixing plate 6 is fixed to the bottom side of the electrode, and the radiation source 3 is deformed by pressing the intermediate part into a substantially U-shape along the upper surface of the protrusion 1. The intermediate portion is press-fitted into the through hole 4, and the radiation source 3 is held between the protrusion I and the edge 4a of the through hole 4.

Such fixing is accomplished by the following operations.

That is, the radiation source 3 is fitted into the recess 5 on the bottom side of the electrode 2.

In this case, the size of the recess 5 is set so that it can be sufficiently fitted even when the radiation source 3 is too long, and the through hole 4 has an inner diameter smaller than the length even when the radiation source 3 is too short.

Therefore, after the above-mentioned fitting, a fixing plate 6 having a protrusion T formed on the bottom side of the electrode 2 is fixed by welding, caulking, or the like.

During this fixing, the protrusion T comes into pressure contact with the radiation source 3 and deforms it, and at the same time press-fits the middle part of the radiation source 3 into the through hole 4 and places the radiation source between the protrusion 7 and the mouth edge 4a of the through hole 40. 3 and is fixed without moving from side to side.

In this case, after fixing the flat fixing plate 6 to the fixed surface of the electrode 2, the center of the fixing plate 6 is pressed and deformed in the direction of the through hole 4 by inserting a punch, and the middle part of the radiation source 3 is inserted into the through hole 4. It may be press-fitted.

As described above, according to the present invention, a recess 5 into which both ends of the radiation source 30 are fitted is formed on the bottom side of the electrode of the through hole 4 formed in the radiation source mounting portion of the electrode 2, and a protrusion is provided in the center. 7
The fixing plate 6 formed by the above structure is fixed to the bottom side of the electrode, and the intermediate part of the radiation source 3 is pressed and deformed along the upper surface of the protrusion 7, and the intermediate part is press-fitted into the through hole 4 to form the protrusion 7. By using a radiation source fixing device for an ionization type smoke detector in which the radiation source 3 is sandwiched between the mouth edge 4a of the through hole 40, the radiation source 3 can be fixed.
The intermediate portion of the holder is fixed to the through hole 4, so that the holder can be attached even if the overall length is shortened.

Moreover, even if the radiation source 3 protrudes slightly from the recess 5, the overall length is shortened by the portion where the radiation source 3 is squeezed into the through hole 4 at the middle portion, so that it is fitted into the recess 5 and fixed.

Furthermore, since the radiation source 3 is press-contacted and deformed to the protrusion 7 of the fixing plate 6 and press-fitted into the through hole 4, the left and right movement is securely fixed regardless of the overall length, and the ionization type has stable detection characteristics. Get a smoke detector.

[Brief explanation of drawings]

FIG. 1 is a bottom perspective view of an electrode showing a conventional radiation source fixing device. 2 to 4 show an embodiment of the radiation source fixing device for the ionization type smoke detector of the present invention, FIG. 1 is a cross-sectional front view before fixing, FIG. 3 is a cross-sectional front view after fixing, and FIG. The figure is a top perspective view of the electrode. 2...electrode, 3...radiation source, 4...
・・・Through hole, 5...(indentation, 6...
・Fixing plate, 7...protrusion.

Claims (1)

[Scope of utility model registration request] Forming recesses into which both ends of the radiation source are fitted on the bottom side of the electrode of the through hole drilled in the radiation source mounting portion of the electrode,
A fixing plate having a protrusion formed in the center is fixed to the bottom side of the electrode, and the intermediate part of the radiation source is pressed and deformed along the upper surface of the protrusion, and the intermediate part is press-fitted into the through hole to form the protrusion. A radiation source fixing device for an ionization smoke detector, which holds a radiation source between the edges of a through hole.