JPH0311906Y2 - - Google Patents

Description

[Detailed description of the invention] <<Industrial application>> This invention relates to electrical meters, and is particularly aimed at dispersing the tensile and compressive loads applied to printed wiring boards when connectors are inserted and removed from terminal fittings. Regarding structure.

<<Prior Art>> Among electric meters such as electric tachometers, some have conventionally had an assembly structure as shown in FIG. 5, for example, in order to obtain ease of connection to an external circuit.

The meter in the figure is a nearly disk-shaped printed wiring board that is placed on the rear mounting plate 1 of the device that constitutes the main body with a predetermined gap provided through a plurality of spacers 2, and is connected to the mounting plate 1 with bolts B. 3
, the rear mounting plate 1 and the printed wiring board 3
A cylindrical outer case 4 with a bottom that covers the outer periphery and rear part of the
and three terminal fittings 5 positioned and fixed to the rear surface of the wiring board 3 via rivets R. This terminal fitting 5 includes a mounting base 5a fixed to the wiring board 3 by the rivet R, and an elongated flat connector 5b bent from the mounting base 5a into an L shape and extending to the rear. It is made up of

After positioning and fitting the rear mounting plate 1 and the wiring board 3 into the exterior case 4, the connector 5
b protrudes to the rear of the exterior case 4 through three slits 4a formed in the bottom or rear surface of the exterior case 4, completing the assembly of the meter.

Therefore, by simply inserting the 3-pole connector 6 for connection to an external circuit into the rear protruding end of the connector 5b, the meter is connected to the external circuit, and the wiring board 3
The device is driven through an internal circuit made up of various elements (not shown) mounted on the device.

<<Problems to be solved by the invention>> However, according to the above configuration, in order to obtain connection with the three-pole connector 6, the terminal fitting 5 is
are densely arranged on the wiring board 3, and the spacers 2 and bolts B cannot be placed in these locations, so that the compressive or tensile load applied to the terminal fittings 5 when the connector 6 is inserted or removed is structurally difficult. It was designed to be attached to the terminal fitting mounting portion of the wiring board 3 through the terminal fitting.

Therefore, if excessive compressive stress or tensile stress is generated in this part during insertion/extraction, buckling will occur from the part indicated by the broken line in the figure, causing an accident that will cause cracking and the resulting disconnection of the internal circuit. I was afraid.

The first possible measure to prevent this type of accident is to change the material thickness or material of the wiring board 3.

However, this type of change is expensive, and essentially the stress due to the load is concentrated in some parts of the wiring board 3 as in the past, and if a load higher than expected is applied, the same will occur. Cracks may occur, or in extreme cases, the rivet may come off when pulled out, and the terminal fitting itself may fall off.

This invention is intended to solve the above problems, and its purpose is to eliminate the concentration of stress on the wiring board without changing the material thickness, material quality, or major modification of the mechanism, thereby preventing the aforementioned problems when inserting and removing connectors. An object of the present invention is to provide an electric meter that can prevent such problems from occurring.

<Means for Solving the Problems> In order to achieve the above-mentioned object, this invention includes a printed wiring board placed via a spacer at the rear of a device constituting the main body of the meter, and a printed wiring board arranged between the device and the wiring board. an exterior case that covers the outer periphery and the rear part; and a plurality of terminal fittings that are protruded from the rear surface of the wiring board and protrude to the rear through slits that are opened at the rear surface of the exterior case, and the rear protruding end of the terminal fittings is provided with a In an electric meter in which a connector is inserted to connect the device and an external circuit, the terminal fitting has a mounting base fixed to the wiring board and an L from the mounting base.
The connector includes a shoulder portion for regulating the protruding position on both ends near the mounting base, and a shoulder portion extending in the insertion direction at the center of the rear side of the shoulder portion. and a protrusion-preventing pawl portion formed to protrude at an incline, and by inserting the connector into the slit of the exterior case, the rear portion of the exterior case can be secured between the shoulder portion and the pawl portion. The present invention is characterized in that the connector is configured to be supported on the rear wall surface of the exterior case while sandwiching the inside and outside of the wall surface.

<<Operation>> According to the above configuration, part of the tensile and compressive loads applied to the terminal fitting when the connector is inserted and removed is transmitted to the board side, but most of it is transferred to the shoulders and claws formed on the terminal fitting. The rear wall of the exterior case receives the stress through the stress and shares the stress.

<<Example>> Hereinafter, an example of this invention will be described in detail using the drawings.

1 to 4 show an electric tachometer, which is an example of an electric meter according to this invention.

It should be noted that the configurations other than the main parts of this invention are the same as or equivalent to the conventional ones, so the reference numerals are the same, and only the main parts will be explained with different reference numerals.

The meter in the figure is a nearly circular disk connected to the mounting plate 1 by bolts B, which is arranged at a predetermined gap via a plurality of spacers 2 on the rear mounting plate 1 of the device that constitutes the main body, as in the conventional case. A shaped printed wiring board 3, a bottomed cylindrical exterior case 4 that covers the outer periphery and rear part of the equipment and the wiring board 3, and three terminals according to this invention positioned and fixed to the rear surface of the wiring board 3 via rivets R. A metal fitting 10 is provided.

As shown in detail in FIG. 2, this terminal fitting 10 includes a mounting base 12 fixed to the wiring board 3 by rivets R, and an elongated plate shaped like an L-shape bent from the mounting base 12. It consists of a connector 14.

On both sides of the connector 14 close to the mounting base 12, there are shoulder portions 16 for regulating the protruding position of the connector 14, and a shoulder portion 16 cut and raised at the center of the rear side of the shoulder portion 16 for preventing removal. A claw portion 18 is provided, and the claw portion 18 is configured to project from the end face of the connector 14 in an inclined state toward the insertion direction thereof.

Connector 14 of terminal fitting 10 configured as above
are positioned and inserted through three slits 4a formed in the rear wall of the exterior case 4, and protrude from the rear of the exterior case 4.

In the inserted state, the claw portion 18 is inserted into the slit 4.
It is inserted while being in sliding contact with the inside of a and being elastically distorted,
When the insertion is completed, it protrudes to the rear surface of the outer case 4 and elastically returns to its original position, and comes into contact with the rear outer wall surface of the periphery of the slit 4a, thereby preventing it from coming out.

At the same time, the shoulder portion 16 abuts against the rear inner wall surface of the outer case 4 to restrict further protrusion of the connector 14.

In other words, the connector 14 is inserted into the rear wall of the exterior case 4 when the insertion is completed. Outside the claw part 18 and shoulder part 1
It will be supported by the rear wall while being sandwiched between the two.

Therefore, when the 3-pole connector 6 is inserted into the connector 14 after the meter is completed, the connector 14 will be pushed and some of its compressive load will be directly applied to the wiring board 3, but a large portion of the compressive load will be applied directly to the wiring board 3. The portion is transmitted to the rear wall surface of the exterior case 4 through the claw portion 18.

Further, when the connector 6 is pulled out, the tensile load is transmitted to the rear wall surface of the exterior case 4 via the shoulder portion 16, and this portion receives the load.

As described above, in either case of insertion or removal, most of the load is transmitted to the outer case 4 side, and this portion mainly receives the load and shares the stress.

Of course, the distance between the shoulder part 16 and the claw part 18 has some looseness in relation to the thickness of the rear wall surface, and this looseness causes a load to be applied to the wiring board 3, but according to experiments, In order to cause the wiring board 3 to buckle, it is necessary to apply a load four times as much as that of a board equipped with a conventional terminal board 5.
Wiring board 3 due to insertion and removal of connector 6 in normal state
It has been confirmed that the cracking phenomenon can be completely eliminated.

<<Effects>> As explained in detail using the embodiments above, in the electric meter of this invention, part of the tensile and compressive loads applied to the terminal fittings when inserting and removing the connector are transmitted to the printed wiring board side. However, in most cases, the rear wall of the outer case is received through the shoulders and claws formed on the terminal fitting.
Since the stress is shared, cracking of the printed wiring board can be prevented.

Further, according to this invention, it can be implemented at low cost because only the shape of the terminal fitting is changed, and the main part of the mechanism is not changed significantly, and the thickness and material of the wiring board are not changed.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of an electric meter according to this invention, Fig. 2 is a perspective view showing the terminal fitting alone,
Figure 3 is an enlarged cross-sectional view of the main parts showing the completed assembled state of the meter, Figure 4 is a cross-sectional view taken along the - line in Figure 3, and Figure 5 is a cross-sectional view taken along the - line in Figure 3.
The figure is an exploded perspective view of a conventional electric meter. 1...Mounting plate (equipment), 2...Spacer, 3...
...Printed wiring board, 4...Exterior case, 4a...
...Slit, 6...3-pole connector, 10...Terminal fitting, 12...Mounting base, 14...Connector, 16...Shoulder part, 18...Claw part.

Claims (1)

[Scope of utility model registration request] a printed wiring board disposed via a spacer at the rear of a device constituting the main body of the meter; an exterior case that covers the outer periphery and rear portion of the device and the wiring board; and an exterior case protruding from the rear surface of the wiring board An electric meter comprising a plurality of terminal fittings protruding rearward through slits opened at the rear surface of the case, and a connector is inserted into the rear protruding end of the terminal fittings to connect the device and an external circuit, wherein the terminal The metal fittings are
It consists of a mounting base fixed to the wiring board and a connector extending integrally from the mounting base in an L-shape, and the connector has shoulders for projecting position regulation on both ends near the mounting base. and a retaining pawl portion cut and raised at the center of the rear side of the shoulder portion so as to project obliquely toward the insertion direction, and the connector is inserted into the slit of the outer case. The electric type is characterized in that the connector is configured to be able to be supported on the rear wall surface of the exterior case with the inside and outside of the rear wall surface of the exterior case sandwiched between the shoulder portion and the claw portion. Instrument.