JPH0532906Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a push button having a structure in which a push button switch is provided on the surface of an instrument that gives instructions and displays (hereinafter referred to as a "display instrument") except for the display position. This relates to instruments with switches.

[Prior Art] Conventionally, as this type of meter with a push button switch, there is known one shown in the schematic sectional views of a conventional meter with a button switch in FIGS. 3 and 4.

In the structure shown in FIG. 3, a surface glass 2 is provided at the display position portion of the front surface of the case 1, and a display surface 3 consisting of a display range A is provided at a lower position of the surface glass 2. A push-button switch (mechanical movable switch) consisting of an integrated switch 4 for operation is embedded in the corner of the surface (surface portion) of the case 1 excluding the display area where the surface glass 2 is installed. .

In the structure shown in FIG. 4, a switch panel 5 having a panel assembly switch 5a is attached to the front surface of a case 10.

[Problems to be solved by the invention] This conventional meter with a push button switch had the following problems.

:The structure shown in Figure 3 is because the integrated switch 4 has a long depth. For this reason, for example, even if it is desired to use a liquid crystal display as a display element, it cannot be used because it would interfere with the lead-out portion of the electrode. That is, there is no degree of freedom in design.

:Also, for items that are subject to environmental changes such as humidity and altitude, such as aviation instruments,
In order to avoid such environmental influences, many devices generally have a sealed structure, but if a mechanical movable switch is buried as shown in the figure, it is difficult to completely seal the entire display instrument. Even if it were possible, it would increase the size and cost of the instrument, which would be disadvantageous in terms of commercialization.

On the other hand, in the structure shown in Fig. 4, since the case 10 and the switch panel 5 are separated, it is possible to create a sealed structure. When viewing, the end portion of the display surface 3 is not visible as indicated by the broken line α.

The present invention was devised in view of the above-mentioned problems of the conventional technology, and its purpose is to provide a switch section with a simple structure on the display instrument surface, while still providing a sealed instrument structure. It is possible to realize this, and also to secure an effective display surface.
An object of the present invention is to provide an instrument with a push button switch that improves the visibility of the display end.

[Means for solving the problem] In order to achieve such an object, the present invention provides:
This device comprises an indirect sensor having a detection coil wound around one end of a coil support part and a temperature compensation coil wound around the other end; a hole provided in a sealed housing of a display instrument and into which the indirect sensor is inserted; an adhesive material that fills the space between the housing and the indirect sensor inserted into the hole with the detection coil on top, thereby keeping the housing airtight; and a target provided in the housing that approaches the detection coil against the elasticity of a spring when pressed, thereby changing the inductance of the detection coil, and is characterized in that pressing this target controls on/off an electric circuit provided in the housing.

[Example] Examples will be described with reference to the drawings.

In the following drawings, parts that overlap with those in FIGS. 3 and 4 are given the same numbers, and their explanations will be omitted.

Fig. 1 is a partial sectional view of a meter with a push button switch showing a specific embodiment of the present invention, and Fig.
It is a figure provided for explanation of a figure.

In FIGS. 1 and 2, a switch portion 6 having a function as a push button switch is embedded in the front surface of the case 100 except for the display position portion into which the surface glass 2 is fitted. This switch part 6 has a predetermined hole provided in the surface excluding the display position part (in this case, the corner part of the surface), and an indirect sensor 6a having an air core coil structure is embedded in this hole. It has a proximity switch configuration in which a dome-shaped target 6b made of an electrically conductive spring material is disposed on the upper part. In the indirect sensor 6a having an air-core coil structure, a detection coil _6a2 is wound around a coil support part _6a1 made of a non-magnetic material such as ceramics on the side facing the target 6b, and then A temperature compensation coil _6a3 is wound around the temperature compensation coil 6a3. A filler 7 such as an adhesive is used around the indirect sensor 6a to securely fix it. Further, the detection coil 6a ₂ and the temperature compensation coil 6a ₃ are connected to the substrate 8. The signal from this board 8 is transmitted via a signal cable 9 to a rectifier circuit 10a, a bridge circuit 10b, an oscillation circuit 10c, an amplifier 10, etc. inside the instrument.
d, and is led to a signal processing circuit 10 comprising a comparator 10e and the like.

In such a structure, the operation is as follows.

Now, consider a case where the switch is pressed while the detection coil 6a ₂ and the temperature compensation coil 6a ₃ are excited at a certain frequency based on the oscillation circuit 10c, that is, the case where the target 6b is pressed as indicated by the arrow α.

When the detection coil 6a ₂ and the target 6b come close to each other, an eddy current is generated in the target 6b, and the inductance of the detection coil 6a ₂ changes. This change in inductance generates a potential difference in the bridge circuit 10b. This potential difference is rectified by a rectifier circuit 10a and then amplified by an amplifier 10d. This amplified output is compared with a reference value in a comparator 10e, and when it exceeds the reference value (that is, when the target 6b is pushed beyond a predetermined position), a contact output is output from the comparator 10e. When the switch operation is completed, that is, when the force of the arrow α is released, the indirect sensor 6a and the target 6b are separated by the spring reaction force (pushing back force) of the target 6b, so that the input to the comparator 10e suddenly changes to the reference value. As a result, the initial state is returned and the contact output is turned off.

By the way, the present invention is not limited to the configuration shown in FIG. For example, the shape of the target may be molded flat and the surface of the indirect sensor may be set slightly lower than the surface of the case, and these modifications can be easily made from a design standpoint. Moreover, it goes without saying that such a structure is not necessarily applied only to instruments with a sealed structure as described above, but can be widely used in general.

[Effects of the invention] Since the present invention is configured as described above, it produces the following effects.

Since the structure of the switch part is only a target and a coil, it is compact and can be installed in a small space, and a sealed structure can be easily realized by sealing the coil part.

Furthermore, since there is no mechanical contact, reliability can be improved.

Furthermore, the movable parts can be easily replaced because they are not connected to the inside of the meter.

Furthermore, it is possible to easily ensure an effective display surface, and it is possible to improve the visibility of the display edges.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view of a meter with a push button switch showing a specific embodiment of the present invention, and Fig.
FIGS. 3 and 4, which are used to explain the drawings, are schematic sectional views of a conventional meter with a push button switch. DESCRIPTION OF SYMBOLS 1...Case, 2...Front glass, 3...Display surface, 4...Integrated switch, 5...Switch panel, 6...Switch part, 6a...Indirect sensor, 6
b... Spring material (target), 10... Signal processing circuit.

Claims (1)

[Scope of Claim for Utility Model Registration] An indirect sensor in which a detection coil is wound around one end of a coil support part and a temperature compensation coil wound around the other end, and the above-mentioned indirect sensor is provided in a housing of a display instrument having a sealed structure. a hole into which an indirect sensor is inserted; an adhesive member filled between the indirect sensor inserted into the hole with the detection coil facing upward and the casing to keep the casing airtight; and the casing. a target that approaches the detection coil against the spring elasticity when pressed and changes the inductance of the detection coil; An instrument with a push-button switch that controls on/off electrical circuits.