JPS62190628A - Proximity switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Industrial Application Field The present invention is a high-frequency oscillation type proximity switch in which a detection coil is formed by a plurality of coil patterns that can be folded into a bellows shape. The present invention relates to a proximity switch that can adjust the number of windings to suit the size and shape of a detection object.

(B) Prior Art Generally, a high frequency oscillation type proximity switch is equipped with a detection coil for changing the conductance of the oscillation circuit in response to the arrival of an object. This type of proximity switch is traditionally
The detection coil used is one in which a wire is wound around a pincushion-shaped coil bobbin, or one in which a coil pattern is printed and wired on a printed circuit board.

(c) Problems to be solved by the invention In the above-mentioned method in which the wire-wound coil is wound around a bobbin, there is a limit to the number of turns of the coil, the switch itself becomes large, and its uses are limited. There was a disadvantage. Also,
In the case of forming a coil pattern on a printed circuit board, although thinning and miniaturization can be achieved, there is a limit to how narrow or thin the distance between spiral patterns can be made due to the manufacturing technology of pattern formation, and it is necessary to increase the number of turns. There were disadvantages such as poor detection efficiency as a proximity switch.

On the other hand, in recent years, it has become common to provide bending lines on printed circuit boards.
A method has been considered in which the coil patterns provided through the bending lines are stacked in an overlapping manner to increase the total number of turns of the coil.

However, in this method, the total number of turns of the flexible substrate is fixed. Therefore, in order to accommodate detection objects of various lengths and sizes, it is necessary to prepare many types of flexible substrates with different coil shapes, which has the disadvantage of lack of versatility in terms of use.

This invention solves the above-mentioned problems of conventional devices, is small and thin, has high coil detection efficiency,
Another object of the present invention is to provide a proximity switch that can easily change the overall number of turns of a flexible substrate depending on the object to be detected.

(d) Means and operation for solving the problem The proximity switch of the present invention includes an insulating thin plate substrate (21) that is divided into a plurality of equal area sections by a cutting and folding line (22);
A circuit element (44) including an oscillation circuit mounted on one section of the insulating thin board, a shield pattern section (5) formed on one of the other sections of the insulating thin board, and the insulating thin board A spiral coil pattern portion (3) formed on one side of each of the plurality of sections other than the above-mentioned sections of the substrate, and which overlaps each other when the insulating thin plate substrates are folded and laminated in a bellows shape along the fold line; Wiring pattern portions (24, 25) formed on the other side to connect the coil patterns in series and forming a pair of terminals (23) when cut along the fold line; and a core (1) for accommodating a detection coil formed by laminating the coil pattern section and the wiring pattern section, and the circuit element, the shield pattern section, the detection coil and the core are It is stored integrally.

In a proximity switch having such a configuration, a large number of t-coil patterns are continuously formed through a folding line that also serves as a cutting line. Therefore, by bending the fold line into a bellows shape and overlapping each joint surface, a thin oscillation coil with a large number of turns can be formed, and a small oscillation circuit can be easily formed.

Moreover, a pair of short-circuit patterns (a pair of terminals) are provided on the fold line of each coil pattern, and the pair of short-circuit terminals are not initially connected. Therefore, when the coil pattern is cut along an arbitrary crease line depending on the object to be detected, a pair of short-circuit terminals emerges from the cut end surface of the coil pattern in an open state.

A flexible circuit board having an arbitrary number of turns can be formed by simply soldering the short-circuit pattern on the cut end surface, and a highly sensitive proximity switch corresponding to the object to be detected can be easily obtained.

(e) Embodiment FIG. 1 is a perspective view showing a specific embodiment of a proximity switch according to the present invention.

The proximity switch consists of a core 1 and a flexible substrate 2 arranged inside the core 1 and stacked and folded into a bellows shape. The proximity switch is shown mounted in a case 7.

FIG. 2 shows the cross-sectional state of FIG. 1.

The core 1 is, for example, a ferrite core with an E-shaped cross section, and an internal hollow chamber 11 has a magnetic core (bar shaft) 12 protruding from the center thereof, and the flexible substrate 2 is attached to this hollow chamber 11 as will be described later. A portion of the coil pattern 3 is fitted, and a circuit portion 4 and a shield pattern 5 located at one end of the flexible substrate 2 protrude outward from the core 1.

FIG. 3 is a plan view showing the flexible substrate 2 in an expanded state.

The flexible board 2 includes a strip-shaped thin insulating mounting board 2.
A coil pattern 3, a circuit portion 4, and a shield pattern 5 are formed on the surface of the device 1.

The thin insulating substrate 21 is formed with folding lines 22 which are also used for cutting at regular intervals within the plane, and the substrate 21 is divided into a plurality of sections by the folding lines 22 and is configured to be folded into a bellows shape. ing.

At one end of this thin insulating substrate 21, a circuit portion 4 is formed at an offset position, that is, on the back surface side, through the fold line 22,
A shield pattern 5 is provided on the front side. This shield pattern 5 is located closer to the metal mounting plate (not shown) than the circuit section 4 in the overlapping state, and is provided so that the circuit section 4 is not affected by external electrical influences.

The circuit section 4 includes an electronic circuit element (IC) 44 having a built-in oscillation circuit, etc. mounted on a circuit pattern 43 having two power terminals 41, 41, one output terminal 42, etc. Further, the shield pattern 5 has an inward notch 51 formed at the end on the circuit section 4 side, and a capacitor 6 is provided at a position corresponding to the notch 1 51 on the back side of the substrate of the shield pattern 5. and is connected in parallel to the detection coil formed by the coil pattern 3.

Further, on the thin insulating substrate 21, a plurality of spiral coil patterns 31a, 31b,
31c, 31d, and 31e are continuous via the fold line 22.

These coil patterns 31a, 31b, 31C131
d and 31e are formed on the same surface as the shield pattern 5 surface. A pair of coil patterns adjacent to each other across the fold line 22, for example, 31a and 31b (31
C and 31d) are set so that the coil patterns 3 generate magnetic flux in the same direction when the thin insulating substrate 21 is folded into a bellows shape at the fold line 22 and overlapped by forming spirals in opposite directions. ing.

In addition, each coil pattern (31a, 31b, 31C13
1d, 31e) has a positioning hole 26 opened in the center that penetrates the substrate 21, and this hole 26 is inserted into the core 1.
It is designed to be inserted into the magnetic core 12 of.

Furthermore, each coil pattern 31a, 31b, 31C131
A short-circuit pattern (a pair of short-circuit terminals 23a and 23b) 23 is provided on each fold line 22 that partitions d and 31e. The pair of shorting terminals 23a and 23b are both through-hole terminals, but are not connected to each other. Each terminal 23 on one side of this short circuit pattern 23
a and C. The circuit portion 4 and the shield pattern 5 are connected via pin terminals 52 by wiring patterns 24 arranged on the back side (the side where the circuit portion 4 is located) of the thin insulating substrate 21, respectively. The other terminals 23b of this short circuit pattern 23 are connected to each coil pattern 3 (for example, 3
It also serves as the tip (spiral outer peripheral end) terminal of l b).
This terminal 23b is connected to the spiral base end terminal 32 of the adjacent coil pattern 3 (for example, 31a) via a wiring pattern 25 arranged on the back side of the thin insulating substrate 21.

The coil pattern located at the final end of the coil pattern 3, 31e in the embodiment, has a pair of shorting terminals 23a and 23b exposed in an open state from its end face. Both terminals 23a and 23b are short-circuited by a solder bridge 27. In other words, coil pattern 3 is similar to wiring pattern 2.
4.25 and a solder bridge 27 to form a detection coil, which is connected in parallel to the capacitor 6.

The electronic circuit element 44 of the circuit section 4 is equipped with a sensitivity adjustment volume 45, so that when the flexible substrate 2, that is, the coil pattern 3 is cut at an appropriate number position (for example, the 31C position), the coil This allows the sensitivity to be adjusted according to the number of turns.

Further, both sides of the flexible substrate 2 are covered with flexible insulating films (not shown) so that the coil patterns 3 that come into contact with each other in the folded and superposed state are not short-circuited.

In the embodiment, an example was shown in which the flexible substrate 2 had five consecutive coil patterns 3, but in this example, for example, five coil patterns 3 of a long flexible substrate 2, such as 10 consecutive coil patterns 3, were used. Set the eye position (31e),
An example of cutting on the fold line 22 is shown.

In the proximity switch having such a configuration, a large number of coil patterns 3 are continuously formed via the cutting and folding lines 22. Therefore, a thin oscillation coil with a large number of turns can be formed by simply bending the crease line 22 into a bellows shape and loading the bonded surfaces into the hollow chamber 11 of the core 1 in a state where they overlap. A circuit can be easily formed. Further, when loading the flexible substrate 2 onto the core 1, the through holes 26 of the coil pattern 3 exert a positioning effect to allow the magnetic core 12 to be inserted therethrough, so that the flexible substrate 2 can be easily loaded.

Moreover, each coil pattern 3 has a pair of short circuit patterns (
A pair of terminals) 23 are provided. Therefore, the coil pattern 3 can be cut at any fold line 22 depending on the object to be detected.
By cutting at this arbitrary position, a pair of shorting terminals 23a and 23b emerge from the cut end surface of the coil pattern 3.

By simply bridging the short-circuit pattern 23 on the cut end surface with solder, coil patterns 3 having an arbitrary number of turns can be connected in series, and a desired flexible substrate 2 can be obtained. Thus, long and short,
A detection coil that exhibits the highest detection sensitivity can be easily obtained with a number of turns that corresponds to detection objects of various sizes.

In addition, in the above embodiment, the shield pattern 5 is connected to the substrate 2.
A shield pattern may be formed on the back side of the coil pattern 31a, or a shield pattern may be provided on the back side of the coil pattern 31a.

(f) Effects of the Invention In this invention, as described above, a plurality of coil patterns are arranged through the cutting and folding line of the board, a pair of short circuit patterns are provided on each folding line, and a pair of short circuit patterns are provided at the final end. We decided to solder bridge the shorting terminal of the coil pattern.

According to this invention, the circuit section and a large number of continuous coil patterns are provided on the same substrate with the fold line interposed therebetween.

Therefore, there is no need to solder the circuit section and the coil section, and the coil pattern can be cut along any desired fold line, making it easy to obtain a coil pattern with the number of turns corresponding to the detection object.

Furthermore, since a short circuit pattern is provided on the fold line, multiple coil patterns can be connected in series by simply soldering a pair of short circuit terminals exposed at the cut end surface of the cut coil pattern at any position. Can be connected on top.

Therefore, the present invention not only provides a small and thin proximity switch, but also enables the easy formation of a coil pattern with a number of turns that exhibits the highest detection sensitivity depending on the various detection objects, and also allows for easy formation of a coil pattern within the core. This invention has excellent effects such as being able to provide a proximity switch that can be loaded into the device.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a proximity switch according to the present invention;
FIG. 2 is a sectional view, and FIG. 3 is a plan view showing the flexible substrate in an expanded state. 1: Core, 2: Flexible board, 3:
Coil pattern, 4: Circuit section, 5: Shield pattern, 21: Insulating thin board, 22: Cutting and fold line, 2
3a and 23b: short-circuit terminals, 24 and 25: wiring pattern, 44: electronic circuit element. Patent applicant Tateishi Electric Co., Ltd. Agent
Patent Attorney Shigeru Nakamura Figure 2

Claims (1)

[Claims] (1) An insulating thin board that is divided into a plurality of sections of equal area by cutting and folding lines, a circuit element including an oscillation circuit that is mounted on one of the sections of the insulating thin board, and the other of the insulating thin board a shield pattern portion formed on one of the sections; and a shield pattern section formed on one side of each of the plurality of sections other than the section of the insulating thin plate substrate, which overlap each other when the insulating thin plate substrates are folded in a bellows shape along the fold line and stacked. a spiral coil pattern portion; and a wiring pattern portion formed on the other side of each of the plurality of sections to connect the coil patterns in series, and forming a pair of terminals when cut along the fold line. a means for short-circuiting the pair of terminals, and a core that accommodates a detection coil formed by laminating the coil pattern section and the wiring pattern section, the circuit element, the shield pattern section, the detection coil, and the core. A proximity switch characterized by integrally housing.