JPH0131199B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a key structure in an electronic musical instrument.

[Prior art and its problems] Electronic musical instruments generally have a structure as shown in FIG. 5, in which when a key is pressed, a predetermined switch is turned on to produce sound. That is, a locking window 1a is formed in the vertical part of the keyboard chassis 1, a through hole 1b and a stopper hole 1c are formed in the flat part, and a movable window 1a is formed in the back side of the keyboard chassis 1 corresponding to the through hole 1b. An elastic body 4 having a bulging portion 3 in which the contact 2 portion is bulged upward, a printed circuit board 6 on which a pair of fixed contacts 5 are formed corresponding to the movable contact 2, and predetermined wiring is provided. are stacked, and the bulging portion 3 protrudes from the through hole 1b.

Reference numeral 7 denotes a key, and a locking portion 8 formed at one end in the longitudinal direction is locked by the locking window 1a, and a locking portion 8 is located at a position facing the stopper hole 1c. An L-shaped stopper 9 is provided facing in the opposite direction, and this stopper 9 is locked by the stopper hole 1c and is normally held upwardly by a return spring 10. There is.

A pressing portion 11 is formed on the key 7 at a position facing the bulging portion 3 protruding from the through hole 1b, and the pressing portion 11 presses the bulging portion 3 when the key is pressed.
is pressed, the pair of fixed contacts 5 are brought into conduction by the movable contact 2, and a predetermined sound is produced.

In addition, at the position where the key 7 and the keyboard chassis 1 come into contact with each other when a key is pressed, there are sound-deadening members 12a, 12 such as felt.
b is attached.

However, in the case where the bulging part 3 is pressed by the pressing part 11 formed on the key 7 as described above, the upper surface of the bulging part 3 must be pressed uniformly in order to ensure reliable input. First, the bottom surface of the pressing portion requires a relatively wide flat surface.

Therefore, as shown in FIG. 6, the entire pressing portion 11a of the key 7 may be formed into a rectangular parallelepiped projecting shape having a wide flat surface, but if the key 7 is made of synthetic resin. In the case of molding, as shown in FIG.
Due to the resin molding process, a concave distortion called a "sink mark" may occur on the surface of the key 7 facing the key 7, which may impair its appearance. Therefore, in order to prevent this distortion, as shown in FIG. 8, when the pressing part 11b is provided in an L-shape projecting from one side of the main body of the key 7, the pressing part of the key 7 is There is a problem in that force is applied only to one side of the main body where 11b is formed, and the key is likely to be twisted, making it difficult to operate the key reliably.

In addition, in order to be able to further press the key 7 from the position where the movable contact 2 conducts the fixed contact 5 by pressing the key 7 during performance, a cylindrical elastic body is integrated on the upper surface of the bulge 3. It is conceivable to form the bulge into a molded shape. However, in this case, since the bottom surfaces of the pressing portions 11a and 11b are flat, when the key 7 is pushed in, the cylindrical portion is attracted to the bottom surface of the pressing portions 11a and 11b at the bulging portion and separated. There are problems such as the key returning slowly, which hinders accurate performance.

In general, the movable contact 2 is pressed by pressing the key 7.
After contacting the fixed contact 5, the key 7 is
However, with conventional key structures, even if you try to perform such a pressing operation, the elastic compression of the thick part of the bulge 3 that fixes the contact point 2 However, there was a problem in that only the pressure amount of the pressing operation could be elastically absorbed, and a sufficient pressing operation could not be performed.

[Object of the Invention] This invention has been made in view of the above-mentioned conventional problems, and it is possible to perform a sufficient pressing operation on the key body when the key body is pressed, and also to be able to perform a sufficient pressing operation on the key body when the key body is released. An object of the present invention is to obtain a key structure for an electronic musical instrument that can reliably prevent the occurrence of an adhesion state between a bulging part and a pressing part.

[Example] Hereinafter, an example according to the present invention will be described in detail based on FIGS. 1 to 4. In the drawings, the same parts and the same names as those shown in the conventional example are given the same reference numerals, and the explanation thereof will be omitted.

FIG. 1 is a longitudinal sectional view showing an embodiment of a key structure according to the present invention, and FIG. 2 is a perspective view showing a key used in the present invention.

The key 13 according to this embodiment is also provided with a locking portion 8 and a stopper 9, as in the case of the key 13 shown in the conventional example described above. Further, this key 13 is made of synthetic resin such as plastic. Further, at a lower position of this key 13, a pressing part 1 for pressing the upper part of a cylindrical elastic cylindrical part 3b formed to protrude from the upper part of the bulging part 3a, which will be described later.
4 are integrally molded. As shown in FIGS. 2 and 3, the pressing portion 14 includes a central protruding portion 14a that protrudes downward from a lower position of the key body 13a constituting the main body of the key 13, and It is integrally formed from a plurality of strips 14b extending radially from the portion 14a toward the periphery. In this embodiment, four strips 14b are integrally molded in a cross shape.

On the other hand, the bulging part 3a pressed by the above-mentioned pressing part 14 is formed to bulge upward from the elastic body 4 disposed on the printed circuit board 6, and the bulging part 3a is formed to bulge upward from the elastic body 4 disposed on the printed circuit board 6. The movable contact 2 is integrally provided. When the bulge 3a is pressed downward, the movable contact 2 comes into contact with the fixed contact 5 fixed on the printed circuit board 6 and at a position within the hollow of the bulge 3a. It's becoming like that. Further, on the upper surface of the bulge portion 3a,
A cylindrical elastic cylindrical portion 3b is integrally molded. The upper part of this elastic cylindrical part 3b is connected to the above-mentioned pressing part 14.
The bottom surfaces of the plurality of strips 14b constituting the holder are pressed at the same time. The elastic cylindrical portion 3b is pressed in its entirety by the pressing portion 14, and therefore, after the movable contact 2 contacts the fixed contact 5, the key 13 is further pressed down. In this case, the elastic cylindrical portion 3b itself is provided to enable further depressing of the key 13 by elastically compressing itself in the axial direction. When this push-down operation is performed, the gas inside the elastic cylindrical portion 3b is transferred to each of the strips 14b...
...The key 1 is ejected to the outside through the space between
When the key 3 is released, the upper part of the bulging part 3a and the bottom surface of the pressing part 14 are attracted to each other, and the bulging part 3a is moved up integrally with the upward movement of the key 13. can be prevented, and therefore,
The key 13 can be released quickly and smoothly.

When attaching the key 13 formed as described above to the keyboard chassis 1, as in the conventional case, the key 13 is attached to the keyboard chassis 1.
Insert the L-shaped stopper 9 into the stopper hole 1c formed in the keyboard chassis 1 while pushing against the return spring 10 so that the locking part 8 of 3 engages with the locking window 1a of the keyboard chassis 1. (See Figure 3).

In this way, in the key 13, the central protrusion 14
Since the pressing part 14 is formed by integrally protruding the cross-shaped strips 14a and a plurality of strips 14b made of synthetic resin, "sink marks" occur on the surface of the key 13 at the positions where the pressing part 14 is protruded. No distortion occurs and the appearance can be improved.

Furthermore, when the key 13 is pressed, the upper part of the elastic cylindrical part 3b can be pressed simultaneously with the bottom surfaces of the plurality of strips 14b constituting the pressing part 14, so that the entire upper part of the bulging part 3a can be pressed. Not only can the movable contact 2 be pushed downward in a well-balanced manner, but also when the movable contact 2 comes into contact with the stationary contact 5, not only the bottom surface of each of the strips 14b but also the bottom surface of the central protrusion 14a can be pressed down. Each strip 14b
The movable contact 2 can be brought into reliable contact with the fixed contact 5 because the entire upper part of the bulging portion 3a is pressed in a uniform manner in cooperation with the above. Furthermore, while the bulging portion 3a is being pressed by the pressing portion 14, the gas within the elastic cylindrical portion 3b is transferred to each of the strips 14b...
Since the gas is discharged to the outside through the gap between Therefore, the key 13 can be released smoothly and quickly.

Further, when pressing the key body 13a after the movable contact 2 contacts the fixed contact 5 when pressing the key body 13a, if the key body 13a is further pressed, the thick part of the bulge 3 that fixes the movable contact 2 In addition to elastic compression, elastic compression in the axial direction of the elastic cylindrical portion 3b is taken into consideration, so that the amount of pressure corresponding to the pressing operation can be sufficiently elastically absorbed. It can be carried out.

[Modification] Note that the shape of the pressing portion 14 of the key 13 is such that a plurality of strips 14b are connected to the central protruding portion 1 as in the above embodiment.
It is formed in a cross shape, extending in all directions from 4a toward the periphery, but in addition to this shape, for example, as shown in FIG.
4b may have a shape extending from the central protrusion 14a toward the periphery in six directions.

Furthermore, the mounting structure of the key 13 and the shape of the stopper 9 in the above embodiment are not limited to these, and can be modified in various ways without departing from the gist of this embodiment.

[Effects of the Invention] As detailed above, according to the present invention, when the key body is pressed, the upper part of the elastic cylindrical part is simultaneously pressed by the bottom surfaces of the plurality of strips constituting the pressing part. Therefore, not only can the entire upper part of the bulge be pushed downward in a well-balanced manner, but also the bottom surface of each of the strips can be pushed down at the stage where the movable contact contacts the fixed contact. Since the bottom surface of the central protrusion also cooperates with each of the strips to uniformly press the entire upper part of the bulge, the movable contact can be brought into reliable contact with the fixed contact. In addition, while the bulging part is pressed by the pressing part, the gas in the elastic cylindrical part is discharged to the outside through the gaps between the strips, so when the key body is released, , it is possible to prevent the upper part of the bulging part and the bottom face of the pressing part from moving upward in a state where they stick to each other,
Therefore, the key body can be released smoothly and quickly.

Furthermore, when pressing the key body after the movable contact contacts the fixed contact when the key body is pressed, in addition to the elastic compression of the thick part of the bulge that fixes the movable contact, Since elastic compression in the axial direction of the elastic cylindrical portion is taken into account, it is possible to sufficiently elastically absorb the amount of pressure corresponding to the pressing operation, and therefore, a sufficient pressing operation can be performed.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view showing an embodiment of the key structure according to the present invention, Fig. 2 is a perspective view showing the entire key used in this embodiment, and Fig. 3 is a state in which the key of the embodiment is installed. FIG. 4 is a plan view of the main part of a key showing another embodiment of the present invention, and FIGS. 5 to 8 are
The drawings are diagrams for explaining a conventional example, in which Fig. 5 is a longitudinal cross-sectional view showing a state in which a key is attached to a keyboard chassis, and Figs. 6 to 8 are perspective views showing the external appearance of the key. DESCRIPTION OF SYMBOLS 1...Keyboard chassis, 2...Movable contact, 3a...Bulging part, 3b...Elastic cylindrical part, 5...Fixed contact, 13a...
Key body, 14... Pressing part, 14a... Central protruding part, 1
4b...Multiple strips.

Claims (1)

[Scope of Claims] 1. A pressing part protruding downward is integrally molded at a lower position of the key body, and a pressing part is molded to bulge upward at a position facing the pressing part,
A bulge in which a movable contact is integrally arranged is provided at approximately the center of the lower surface, and when the key body is pressed, the upper part of the bulge is pressed, and the pressure causes the movable contact to move. In the key structure for an electronic musical instrument, the key is brought into contact with a fixed contact that is fixed at a predetermined distance from the contact, wherein a cylindrical elastic cylindrical part that protrudes upward is integrally formed on the upper surface of the bulged part. On the other hand, the pressing part includes a central protruding part that protrudes downward from the key body, and a central protruding part that extends radially toward the periphery from at least the bottom side of the central protruding part, flush with the bottom surface of the central protruding part. When the key body is pressed, the bottom surface of each of the strips simultaneously presses the top of the elastic cylindrical portion and the bottom surface of the central protrusion. A key structure for an electronic musical instrument, characterized in that the key is pressed within the elastic cylindrical portion and at a position on the upper surface of the bulging portion.