JPH087435Y2 - Electronic keyboard instrument switch mounting structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial field of application: The present invention relates to a switch mounting structure for an electronic keyboard instrument in which a switch composed of a switch substrate having fixed contacts and a flexible member having movable contacts is mounted on a keyboard chassis. Is.

2. Description of the Related Art The conventional circuit board structure of an electronic keyboard musical instrument has a circuit board as shown in FIG. 5, a hard board 51 provided with contacts, and a screw or nylon rivet on a keyboard chassis 52 as shown in FIG. It is fixed by using a fastening member 53 such as. A circuit network including a carbon contact portion 55 and an electronic component 57 is provided on the hard substrate 51 that is fixed in advance, and a connector 56 that connects this to the external wiring is attached. Then, holes 58 are formed at positions corresponding to the contact rubber 54 and the straight legs 59, respectively.

A contact rubber is attached to the hard substrate 51 fixed to the keyboard chassis 52.
54 is installed. The contact rubber 54 has a plurality of straight legs 59 as shown in FIG. 6, and these straight legs 59 are usually fitted and fixed in the through holes 58 of the hard substrate 51.

Problems to be Solved by the Invention: In the board structure of an electronic keyboard instrument based on such a conventional technique, a step of fixing a hard board to a keyboard chassis first by using a fastening member such as a screw or a nylon rivet is required. Subsequently, a step of sequentially attaching contact rubber to the main part of the hard substrate is required. Therefore, the number of parts that need to be tightened for fixing or attaching each part is increased, and the number of assembling steps is increased, resulting in a high cost.

Further, the hard substrate has a maximum manufacturable length limited to about 500 mm due to the manufacturing process, and a plurality of hard substrates must be used when applied to a keyboard chassis having an overall length of 1200 mm or more. Therefore, it is necessary to use connecting parts such as connectors and wirings, and the number of required parts is increased together with the fastening members, increasing the total number of assembling steps and increasing the cost.

The present invention has been made to solve the above problems, and it is an object of the present invention to reduce the number of parts when mounting a switch on a keyboard chassis of an electronic keyboard instrument and to facilitate assembly.

Means for Solving the Problems: A switch mounting structure for an electronic keyboard instrument according to the present invention includes a switch substrate having fixed contacts, a bulge portion and a base portion around the bulge portion. A switch mounting structure for an electronic keyboard musical instrument, wherein a switch made of a flexible member having a movable contact for conducting the fixed contacts inside is mounted on a keyboard chassis, and a plurality of locking bosses are provided on a lower surface of the base portion. The switch board and the keyboard chassis are provided with a plurality of fitting holes into which the locking bosses are fitted, and the plurality of locking bosses are fitted into the plurality of fitting holes, respectively. The switch substrate is fixed to the keyboard chassis by a flexible member.

The switch substrate is preferably a flexible printed substrate.

The operation and effect of the invention The switch board is fixed to the keyboard chassis in a stable state by tightening the main part with a flexible member having a sufficient locking function with respect to the keyboard chassis. Therefore, a fastening member such as a screw or a nylon rivet is not required, the number of parts is reduced, the man-hour is reduced, and the assembling is easy.

Also, if the switch board is a flexible printed board, unlike the rigid board, this flexible printed board can be manufactured to have any length without any problems in manufacturing. Therefore, a length that matches the entire length of the keyboard chassis can be manufactured. The substrate can be easily obtained, and the surface of the flat keyboard chassis is well followed and contacted, and is securely fixed to the keyboard chassis.

Embodiment: Hereinafter, a specific embodiment of the present invention will be described with reference to the drawings.

A flexible printed circuit board 1 as a switch substrate applied to the present invention is shown in FIGS. 1 and 2. FIG. 1 is a top view of a flexible printed board 1, a contact portion 3 as a fixed contact corresponding to a circuit pattern, a resist layer, and a plurality of keys (not shown), and a chip fixed by a sealant 9. An electronic component 8 such as a diode, a connecting terminal 11 concentrated locally, and a fixing hole 10 for fixing to a keyboard chassis 20 (see FIG. 4) are provided.

FIG. 2 is an enlarged cross-sectional view schematically showing the structure of the flexible printed board 1. The circuit / contact portion A having a circuit and the contact portion 3 on the upper surface of the base film 1'and the chip diode, etc. The chip mounting portion B provided with the electronic component 8 is formed. In the flexible printed board 1, the circuit / contact portion A and the chip mounting portion B are provided on the upper surface of the base film 1 '. The base film 1'has a thickness of 75 to 500, for example.
A polyester resin of about μm can be used.

First, in the circuit / contact portion A, a silver circuit 2 is printed on the upper surface of the base film 1'using silver ink to form a conductor. A contact part 3 is formed on the upper part of the silver circuit 2, and a carbon pattern is printed to prevent the migration (so-called migration) of silver to become the contact part 3.
The resist layer 4 is printed except for the contact portion 3. Further, a conductive layer of silver and a resist layer 6 are printed as a jumper circuit 5 on the resist layer 4.

Further, in the chip mounting portion B, the silver circuit 2 is printed on the upper portion of the base film 1'as a conductive connecting path.

A resist layer 6 is printed thereon to prevent silver migration, except for areas for soldering parts. A chip-shaped electronic component 8 is soldered on it by a conductive cream solder 7, and a sealing agent made of an olefin-based or epoxy-based synthetic resin in order to prevent migration and protect the component from external force and vibration. 9 is used to seal the electronic component 8.

Next, FIG. 3 shows a cross section of a contact rubber as a flexible member applied to the present invention. A material such as silicon rubber which is elastically deformable and has a high durability is used to form a bulge portion 13 by bulging a part of the base portion 14 into a dome shape on the upper portion.
Inside the bulging portion 13, a downward movable contact 12 is provided. The upper surface of the bulging portion 13 serves as a pressing portion 16, and when the pressing portion 16 is pressed by an actuator of a playing key (not shown), the bulging portion 13 is deformed and the contact end surface of the movable contact 12 faces downward. To reach the lower surface level of the base portion 14. In this embodiment, two movable contacts 12 in the bulging portion 13 are arranged side by side, and the heights of the end faces of the contacts are different. Such a mode of contact is advantageous in that there is a time lag in opening and closing each circuit when the movable contact is operated by the force applied to the pressing portion 16. Also,
On the lower surface of the base portion 14, a locking boss 15 having a conical retaining means is projected at the lower end.

The retaining means is not limited to a conical shape as long as it can be smoothly inserted in the forward direction when inserted and cannot be removed in a normal state. The effective length of the shaft leg portion between the lower surface of the base portion 14 and the retaining means is equal to or slightly shorter than the sum of the thickness of the flexible printed board 1 and the thickness of the keyboard chassis 20. .

In this way, the state in which the flexible printed board 1 and the contact rubber 17 respectively formed on the keyboard chassis 20 are formed in the fourth state
As shown in the figure. That is, on the base sheet 1'which is flexible and has a length adapted to the length of the keyboard chassis 20,
The flexible printed circuit board 1 provided with the switch circuit composed of the circuit / contact part A and the chip mounting part B is formed by aligning the points 21 and the points holes 22 such as a plurality of half piercings provided on the upper surface of the keyboard chassis 20. Position and place. In this state, the fixing hole 10 for fixing the flexible printed circuit board 1 and the keyboard chassis 20
And the locking holes 18 formed in the contact rubber 17 and the arrangement of the locking boss 15 under the contact rubber 17. Then, when the locking boss 15 of the contact rubber 17 is inserted into the fixing hole 10 and the locking hole 18, the locking boss 15 is locked on the back surface of the keyboard chassis 20, and the flexible printed circuit board 1 is mounted on the keyboard chassis 20. The above-mentioned action, which is pressed against the upper surface and fixed following the flat upper surface,
Manifest the effect.

The flexible printed circuit board according to the present invention is obtained by the manufacturing steps illustrated in FIG. That is, a silver circuit is formed by screen printing on the annealed base film, and a contact portion is formed by carbon printing. Among the resins having a high electric resistance value such as methacrylic resin and polyurethane resin, the material of the resist layer is preferably one having good adhesion to the polyester resin. The jumper circuit is printed by conductive circuit printing with silver ink, and the encapsulant has excellent adhesion to the base film, is highly water resistant, and is highly stable olefin-based or epoxy-based synthetic that does not adversely affect metals. Resin is used.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a flexible printed circuit board applied to the present invention, FIG. 2 is an enlarged sectional view of an essential part thereof, and FIG. 3 is an example of a contact rubber applied to the present invention. Explanatory drawing of a partial cross section
FIG. 4 is an embodiment of the board structure of the present invention, FIG. 5 is a plan view of a conventional hard board, FIG. 6 is a contact rubber, and FIG. 7 is a view showing a state in which these are fixed to a keyboard chassis. . FIG. 8 is a flow chart illustrating a manufacturing process of a flexible printed circuit board applied to the present invention. DESCRIPTION OF SYMBOLS 1 ... Flexible printed circuit board 1 '... Base film 2 ... Silver circuit, 3 ... Contact part 4,6 ... Resist layer, 5 ... Jumper circuit 7 ... Cream solder, 8 ... Electronic component 9 ... Sealant, 10 ... Fixing hole 11 ... Connection terminal part, 12 ... Movable contact 13 ... Bulging part, 14 ... Base part 15 ... Locking boss, 16 ... Pressing part 17 ... Contact rubber, 18 ... Locking hole 20 ... Keyboard chassis, 21 … Point 22… Point hole 51… Hard board, 52… Keyboard chassis 53… Clamping member, 54… Contact rubber 55… Carbon contact point 56… Connector, 57… Electronic parts 58… Drilling hole, 59… Straight leg A… Circuit・ Contact part, B ... Chip mounting part

Claims (2)

[Scope of utility model registration request] 1. A flexible substrate having a switch substrate having a fixed contact, a bulging portion and a base portion around the bulging portion, and having a movable contact inside the bulging portion for electrically connecting the fixed contacts. A switch mounting structure of an electronic keyboard musical instrument for mounting a switch composed of a flexible member on a keyboard chassis, wherein a plurality of locking bosses are provided on a lower surface of the base portion, and the locking bosses are respectively provided on the switch board and the keyboard chassis. Is provided with a plurality of fitting holes, and the plurality of locking bosses are fitted into the plurality of fitting holes to fix the switch board to the keyboard chassis by the flexible member. A switch mounting structure for the characteristic electronic keyboard instruments. 2. The switch mounting structure for an electronic keyboard instrument according to claim 1, wherein the switch substrate is a flexible printed substrate.