JPS6236137Y2 - - Google Patents

Description

[Detailed description of the invention] Technical field of the invention The invention is applicable to, for example, a tester stick of an electric circuit tester that measures electrical resistance, voltage, current, etc., or a pattern part of a printed circuit board (PC board). The present invention relates to an improvement in a conductive contact needle device used for purposes such as conductive contact pins for electrical measurement adjustment or operation testing.

The technical background of the invention and its problems.

This type of conductive contact needle device that has already been proposed has a stylus (probe) b ₁ in a lower opening a ₁ of a conductive holding cylinder a, as shown in an enlarged view in FIG. The stylus main body b is slidably fitted in a locking portion c formed on a part of the holding cylinder a to prevent it from falling off, and the upper part of the stylus main body b is
A sphere (ball) e is placed on the slope d formed on b ₂ ,
They are pressed together by the elasticity of a coil spring f interposed within the holding cylinder a.

Therefore, when the above-mentioned conductive contact needle device is used as an electric circuit tester, for example, by bringing the stylus b ₁ of the stylus body b into contact with the solder part of a printed circuit board, electrical We are conducting measurements, adjustments, and operation tests. In this case, the stylus body b
The upper part _b2 pushes the inclined surface d sideways by the pressing force of the sphere e biased by the elasticity of the coil spring f, and thereby the inner wall of the conductive holding cylinder a It is designed to be electrically connected by being pressed against it.

However, in the conductive contact needle device described above, when the stylus b ₁ is brought into contact with the solder part, the holding cylinder a
Since there is a slight gap between the inner peripheral wall of the stylus body b and the peripheral wall of the upper part _b2 of the stylus body b, the upper part _b2 peripheral wall of the stylus body b is pressed against the holding cylinder a by the pressing force of the sphere e. Although the solder part is biased and pressed against the inner wall for electrical conduction, if the solder part is curved or has a complicated shape, the stylus _B1 will be affected by the shape of the solder part,
There is also a risk that the upper part _b2 of the stylus body b may become separated from the inner wall of the holding cylinder a, making it impossible to obtain effective conduction.
This makes accurate electrical measurements difficult.

In particular, if the stylus b ₁ of the stylus main body b is formed into a sharp, needle-like shape, there is a risk that the stylus may escape from the curved solder surface or be bent when the stylus is used. If such a stylus b ₁ is used as is, the stylus main body b slides inside the holding cylinder a in a biased state, and the close contact due to pressure contact gradually wears out and is damaged, resulting in electrical conductivity. This method has drawbacks such as not only the performance deteriorates, but also the instantaneous electrical resistance changes greatly, which becomes a major cause of measurement error.

Purpose of the invention The present invention has been developed in view of the above-mentioned circumstances, and is designed to prevent measurement even when the stylus of the stylus body comes into contact with a complex-shaped solder part as the part to be tested. An object of the present invention is to provide a conductive stylus device which aims to enable highly accurate and stable measurement.

Summary of the invention Particularly, the present invention is such that the stylus body is slidably fitted into the opening of the conductive holding cylinder without falling out, and the stylus body has an axial sliding portion at the top. (slit), the upper top surface of the stylus main body is formed with an inclined surface toward the axial direction in which the sliding portion is located, and a sphere is pressed against the inclined surface by the elasticity of a spring, The stylus main body is configured to evenly contact the inner circumferential surface of the holding cylinder so that uneven contact does not occur.

Embodiment of the invention Hereinafter, the present invention will be described with reference to an illustrated embodiment.

In FIG. 2, reference numeral 1 denotes a conductive holding cylinder, the upper part 1a of this holding cylinder 1 is narrowed, and the lower part of this holding cylinder 1 has an opening 1.
It forms b. Further, a stylus main body 2 having a sharpened stylus (probe) 2a is slidably fitted into the opening 1b of the holding cylinder 1.
The upper part 2b and lower part 2c of this stylus main body 2 form a large diameter part.

Furthermore, a locking portion 3 formed by an inner circumferential ring is formed in a part of the holding cylinder 1 where the upper large diameter portion 2b of the stylus main body 2 is located, and this locking portion 3 is provided with a locking portion 3 formed by an inner circumferential ring. It holds the needle main body 2 so that it does not fall off.

On the other hand, an axial sliding part 4 is provided on the upper part 2b of the stylus main body 2, and this sliding part 4 allows the upper part 2b to be opened to both sides.
Further, an inclined surface 5 is formed on the upper top surface of the stylus main body 2 toward the axial direction where the sliding portion 4 is located, and this inclined surface 5 forms a conical recess. There is. Furthermore, a sphere (ball) is placed on this inclined surface 5.
6 is placed thereon, and this sphere 6 is pressed against the upper part 2b of the stylus main body 2 by the elasticity of the coil spring 7 provided in the holding cylinder 1. The legs are elastically spread to both sides so as to evenly contact the inner circumferential surface of the holding cylinder 1,
Thereby, the conductive holding cylinder 1 and the stylus main body 2 are always in contact with each other in a conductive state.

Therefore, when the present invention is used as an electric circuit tester, for example, even if the stylus 2a is brought into contact with the solder portion _W1 of the printed circuit board W, the stylus 2a will not work as described above. In addition, since the upper part 2b of the stylus main body 2 is spread elastically to both sides and is in even contact with the inner circumferential surface of the holding cylinder 1, not only is there constant conduction, but also the solder portion W ₁ Even if the probe has a complicated shape, there is no risk of loss of conduction during the stylus, and stable measurements and motion measurements can be made.

Next, the embodiment shown in FIGS. 3 and 4 is as follows.
This is another embodiment of the present invention, in which the holding cylinder 1 according to the present invention is inserted into a socket 9 of an inspection device 8 using a testing machine, and a notch 10a is formed in an upper opening 9a of the socket 9. The core wire 11a of the lead wire 11 is inserted into the terminal 10, and this is soldered to the cutout portion 10a.
It is designed to perform a unit check on the printed circuit board W, and has the same structure as the embodiment described above.

Effects of the Invention As described above, according to the present invention, the stylus main body 2 is slidably fitted into the opening 1b of the conductive holding cylinder 1 without falling out, and An axial sliding part 4 is provided on the upper part 2b of 2,
The top surface of the upper part 2b of this stylus main body 2 is connected to the sliding portion 4.
forming an inclined surface 5 toward the axial direction where is located;
Since the sphere 6 is pressed against the inclined surface 5 by the elasticity of the spring 7, the upper part 2b of the stylus main body 2 is evenly contacted with the inner circumferential surface of the holding cylinder 1 without being biased. Since it is possible to do this, it has excellent effects such as not only being able to improve measurement accuracy but also being able to perform stable measurements.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conductive stylus device that has already been proposed, FIG. 2 is a sectional view of a conductive stylus device according to the present invention, and FIGS. 3 and 4 are views showing other embodiments of the present invention. It is. DESCRIPTION OF SYMBOLS 1... Holding cylinder body, 2... Contact body, 3... Locking part, 4... Sliding part, 5... Inclined surface, 6... Sphere, 7... Coil spring.

Claims (1)

[Utility Model Claims] 1. The stylus body is slidably fitted into the opening of a conductive holding cylinder so that it does not fall out.
A conductive contact needle device characterized in that a slit is provided in the upper part of the probe body in the axial direction, the top surface of the upper part of the probe body is formed as an inclined surface toward the axial center direction where the slit is located, and a sphere is pressed against the inclined surface by the elastic force of a spring. 2. A conductive contact needle device according to claim 1 of the utility model registration characterized in that a locking portion formed on a part of the holding cylinder is made into an inner peripheral wall, and this inner peripheral wall prevents the probe body from falling off.