JPS5826038B2 - electronic musical instrument cabinet - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cabinet for an electronic musical instrument, and by providing an exterior cabinet with the function of a keyboard chassis and integrally forming it with resin, a high-precision keyboard device can be produced at a low cost. It is designed to be configurable.

FIG. 1 shows the keyboard portion of a conventional electronic musical instrument.

In Fig. 1, a white key 1 and a black key 2 (hereinafter referred to as the single key) are pivoted on the rear end of a chassis 3 so as to be able to move up and down, and are always supported by a spring 4 attached to the top surface of the chassis 3. is lifted upwards.

Further, a key guide 6 is attached to the chassis 3 with screws 5, and a guide book T attached to the tip of the key guide 6 prevents the keys 1 and 2 from swinging laterally.

An L-shaped stopper piece 8 is provided at the lower end of each key 1, 2, and the key moves upward when this stopper piece 8 comes into contact with an upper limit stopper felt 9 affixed to the lower surface of the chassis 3. The upper limit positions of the keys 1 and 2 are regulated, and when the lower ends of the keys 1 and 2 come into contact with the lower limit stopper felt 10 attached to the upper surface of the chassis 3, the lower limit positions of the keys 1 and 2 that move downward are regulated. Regulated.

Further, another protrusion 11 is provided on the lower surface of the keys 1 and 2, which transmits the vertical movement of the keys 1 and 2 to an actuator 12 that constitutes a key switch, and a movable contact piece 13 fixed to this actuator 12. It is moved up and down to contact either the normally closed fixed contact 14 or the normally open fixed contact 15 to open or close the key switch.

Then, the entire keyboard section, which has been assembled integrally around the chassis 3 as described above, is mounted on the shelf board 16a and the front crosspiece 16.
Electronic musical instrument cabinet 16f screw 171 with b
I was rubbing it to make it more abrasive.

However, with this configuration, there are problems in that the number of parts in the keyboard portion increases significantly, which causes an increase in cost and increases the number of assembly steps.

There is also the problem that it is difficult to manage the dimensional relationships of individual parts, and as a result, the dimensional accuracy of the keyboard section and the keyboard section and the cabinet after assembly deteriorates.

The present invention solves the above-mentioned conventional problems at once by providing the exterior cabinet itself with the function of a keyboard chassis, and by integrally molding the cabinet with resin.

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 2, reference numeral 18 denotes a cabinet formed integrally with resin, and this cabinet 18 includes a board for attaching a printed circuit board 28 and a keyboard 22, which will be described later, and a key mounting portion 18a, as well as a key switch, which will be described later. Switch mounting part 18b to which the rear end of the movable contact piece 31 is attached
, a lower limit stopper portion 18C to which the lower limit stopper felt 19 is attached, an upper limit stopper portion 18d to which the upper limit stopper felt 20 is attached, a through hole 18e, and a key 23.24.
A key guide portion 18f for preventing lateral vibration is formed integrally with the key guide portion 18f.

A guide bushing 21 is fitted into the key guide portion 18f.

22 is a keyboard, which in this embodiment has a white key 23 and a black key 24.
, a thin hinge part 25 provided at the rear end of the duplicate keys 23 and 24, and a plurality of keys 2 via this thin hinge part 25.
3. Common mounting part 26 that integrally connects 24 and duplicate key 2
A stopper piece 27 protruding from the lower surface of 3.24 is integrally formed of resin.

On the other hand, 28 is a printed circuit board, on the surface of which there is a copper foil 29 that becomes a normally closed fixed contact and a copper foil 30 that becomes a normally open fixed contact.
is formed.

31 is a movable contact piece made of a conductive metal plate formed into a chevron shape, 32 is a fixed piece, and 33 is a screw.

In the above configuration, the rear end portion of the movable contact piece 31 is connected to the fixed piece 32.
, switch mounting part 1 of cabinet 18 with screw 33
8b, and with the tip of the stopper piece 27 loosely fitted into the through hole 18e of the cabinet 18, connect the common mounting part 26 of the keyboard 22 to the base plate of the cabinet 18 and the key mounting part 18a using screws (not shown) or the like. and attach the printed circuit board 28 to the mounting part 18 using screws (not shown) or the like.
Attach this.

In this way, the lower end of the key 23, 24 can be attached to the movable contact piece 31.
Since the keys 23 and 24 are in contact with the approximate center of the movable contact piece 3
1, and the stopper piece 27 and the front edge 23a of the white key 23 are kept in contact with the upper limit stopper felt 20, respectively.

At this time, since the movable contact piece 31 is always pressed downward by the weight 1 of N23, 24, the tip of the movable contact piece 31 is always pressed against the copper foil 29 as a normally closed fixed contact.

This state (the state shown in FIG. 2) becomes a key-not-pressed state.

From this state, when keys 23.24 are pressed, keys 23.2
4 rotates counterclockwise in FIG. 2 using the thin hinge portion 25 as a fulcrum.

At this time, the guide bushing 21 comes into contact with the side surface of the key 23.24, thereby preventing the key 23.24 from swinging laterally.

The movable contact piece 31 deforms in response to the downward movement of the keys 23 and 24, slides to the right in FIG.
come into contact with.

After the key switch is closed in this way, when the key 23.24 is further pressed downward, the lower end surface of the key 23.24 will eventually come into contact with the lower limit stopper felt 19, and the key 23.24 will no longer be pressed.
prevent it from moving downward.

In this way, by giving the exterior cabinet 18 itself the function of a keyboard chassis, and by molding it integrally with resin, it is possible to significantly reduce the number of parts and assembly man-hours, and the dimensions of the cabinet 18 itself. Since the accuracy can also be increased, the overall dimensional accuracy can be significantly increased.

In addition, in the embodiment, the upper limit stopper part 1 is provided in the cabinet 1B.
8d is also formed integrally, but in general, in order to mold such a shape, it is necessary to use a method such as using a side core, so there are cases where it is difficult to integrally mold it with other shapes. There is also.

In such a case, only the upper limit stopper portion 18d may be molded separately, and when assembled together with the other portions, it may substantially constitute one cabinet.

As described above, the present invention provides an exterior cabinet for an electronic musical instrument with the functions of a conventional keyboard chassis, and the mechanical and electrical components constituting the keyboard section are directly attached to this cabinet. It is possible to achieve simplification, a reduction in the number of parts, and a reduction in assembly man-hours, as well as excellent effects such as higher dimensional accuracy because the individual mounting parts provided on the cabinet are formed by one molding.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a keyboard section of a conventional electronic musical instrument, and FIG. 2 is a side sectional view showing an embodiment of the present invention. 18...Cabinet, 18a...Key mounting part, 18b...Switch mounting part, 18c.
...Lower limit stopper part, 18d...Upper limit stopper part, 18f...Key guide part, 23.
...White key, 24...Black key, 25...
...Thin wall part for hinge, 26...Common mounting part, 2
7...stopper piece, 28...printed circuit board, 29°3θ...copper foil, 31...
Movable contact piece.

Claims (1)

[Claims] 1. At least a stopper part that defines the lower limit position of the key that moves up and down around the vicinity of the rear end, a key guide part that prevents the key from swinging laterally, and a switch that opens and closes when the key moves up and down. Q) An electronic musical instrument cabinet, characterized in that a switch mounting part to which the movable contact piece is attached and a key mounting part to which the rear end of the key is attached are integrally formed of resin.