JPH04369292A - Part fixing structure of electronic measuring instrument - Google Patents

Abstract

PURPOSE:To fix a circuit part without using adhesives by a method wherein a part of the circuit part is held by circuit part holding parts having flexibility of a sealed housing. CONSTITUTION:In a circuit part 4 on a circuit board 3, a terminal part is inserted into a fitting hole of the circuit board 3 and performed soldering 6 onto land patterns. Further, in places corresponding to locations of the circuit part 4 of an upper sealed housing 2a, there is a pair of a circuit part holding part 2d which is an arm having flexibility. Here, the interval is so set as to be narrower than a thickness of the circuit part 4 and the height corresponds to the circuit part 4. Thus, after the circuit part is soldered on the circuit board, when the upper sealed housing is set and fixed onto the circuit board together with a lower sealed housing, the circuit part holding part of the upper sealed housing is engaged with the circuit part.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component fixing structure for electronic measuring instruments.

0002

2. Description of the Related Art Conventional parts fixing structures for electronic measuring instruments have generally had a structure as shown in FIG.

[0003] Here, 1 is a housing, 2a is an upper shield housing, 2b is a lower shield housing, 2c is a shield housing fixing screw, 3 is a circuit board, 4 is a circuit component, and 5 is a silicone adhesive.

[0004] The terminal portion of the circuit component 4 is inserted into the mounting hole of the circuit board 3, and is fixed onto the land pattern by soldering. Then, the main body portion is adhesively fixed onto the circuit board 3 using a silicone adhesive 5 so that it does not move even when subjected to vibrations or shocks.

[0005]

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, since it is fixed using silicone adhesive, there are many management items during work, such as controlling the amount of application, managing the application position, and storage conditions. Furthermore, due to these variations, the fixing strength fluctuates, and the strength is likely to be insufficient, resulting in a lack of reliability.

Furthermore, in terms of workability, adhesion is a troublesome work and requires a large number of man-hours, and is not preferred by process workers.

SUMMARY OF THE INVENTION The present invention aims to solve these problems, and its purpose is to provide a simple structure for fixing circuit components without using adhesives.

[0008]

[Means for Solving the Problems] The component fixing structure of an electronic measuring instrument of the present invention comprises a housing, an electronic measuring circuit comprising a circuit board and circuit components, and a shield housing for shielding the electronic measuring circuit. The device is characterized in that a part of the circuit component is held between a flexible circuit component holding portion of the shield housing.

[0009]

According to the above structure of the present invention, the circuit components on the circuit board are held and fixed by the flexible circuit component holding portion of the shield housing.

0010

[Embodiment] Fig. 1 is a sectional view of main parts in an embodiment of the present invention, in which 1 is a housing, 1a is a housing fixing screw, 2a is an upper shield housing, 2b is a lower shield housing, 2c
2d is a flexible circuit component holding portion on the upper shield housing, 3 is a circuit board, 3a is a circuit board fixing screw, and 4 is a circuit component.

The electronic measurement circuit consisting of the circuit board 3, circuit components 4, and other circuit components such as an AD converter, CPU IC, various sensors, memory IC, etc. (not shown) is susceptible to external noise, static electricity, or self-generated electrical noise. Upper shield housing 2 for shielding etc.
The main parts are covered by the lower shield housing 2b and the lower shield housing 2b. The upper shield housing 2a and the lower shield housing 2b are made of conductive synthetic resin mixed with metal filler in order to obtain a shielding effect, and are fixed to the top and bottom of the circuit board 3 by shield housing fixing screws 2c.

The insert pins 2e and 2f of the upper shield housing 2a and the lower shield housing 2b are made of metal and are pressed into contact with the ground pattern of the circuit board 3, thereby determining the potentials of the upper shield housing 2a and the lower shield housing 2b.

The circuit board 3 of the electronic measurement circuit attached to the upper shield housing 2a and the lower shield housing 2b is fixed to the housing 1 by circuit board fixing screws 3a.

The housing 1 is divided into upper and lower parts, which are integrated into one body after the electronic measuring circuit is installed using a housing fixing screw 1a.

Here, the terminal portion of the circuit component 4 on the circuit board 3 is inserted into the mounting hole of the circuit board 3, and is soldered 6 to the land pattern. Furthermore, a pair of circuit component holding parts 2d, which are flexible arms, are provided at locations corresponding to the positions of the circuit components 4 on the upper shield housing 2a, and the distance between them is determined by the thickness of the circuit components 4. It is set narrowly. Further, its height is also a height corresponding to the circuit component 4.

As a result, after soldering the circuit components 4 onto the circuit board 3, the upper shield housing 2a is attached to the circuit board 3.
By setting the upper shield housing 2b on the circuit board 3 together with the lower shield housing 2b,
The circuit component holding portion 2d of a is engaged with the circuit component 4.

When the circuit component holding portion 2d engages with the circuit component 4, the interval therebetween is narrower than the thickness of the circuit component 4, so the circuit component holding portion 2d bends outward, and the circuit component 4 is held and fixed by the reaction force. becomes possible.

Further, as shown in the figure, the circuit component holding portion 2d is provided with a slope at the tip thereof, and consideration is given to prevent the circuit component holding portion 2d from riding on the circuit component 4 when engaged with the circuit component 4.

[0019]

As described above, according to the present invention, by providing a flexible circuit component holding portion on a shield housing, circuit components can be mounted on a circuit board without using an adhesive. This has the effect that it can be easily fixed simply by setting the shield housing.

[Brief explanation of drawings]

FIG. 1 is a main sectional view showing an embodiment of a component fixing structure for an electronic measuring instrument according to the present invention.

FIG. 2 is a main cross-sectional view showing a component fixing structure of a conventional electronic measuring instrument.

[Explanation of symbols]

1 Housing 2a Upper shield housing 2b Lower shield housing 2d Circuit component holding part 3 Circuit board 4 Circuit parts

Claims (1)

[Claims] 1. An electronic measuring instrument comprising a casing, an electronic measuring circuit comprising a circuit board/circuit components, and a shield housing for shielding the electronic measuring circuit, wherein a part of the circuit components is a part of the shield housing. A component fixing structure for an electronic measuring instrument characterized by being held between flexible circuit component holding parts.