JPH077267B2 - Keyboard device for electronic musical instruments - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a keyboard device for electronic musical instruments, and particularly to a keyboard device having a touch close to that of a piano.

2. Description of the Related Art In recent years, efforts have been made to provide a keyboard with a simple structure with a touch close to that of a piano for electronic musical instrument keyboards. It had drawbacks such as large variations in the progress point.

The structure of the above-described conventional keyboard device will be described below with reference to the drawings. In each figure, the same members are given the same numbers.

Fig. 4 shows an example of using a U-shaped leaf spring (Jitsuko Sho 47).
−1561 publication). In FIG. 4, white key or black key 1
One end of a U-shaped leaf spring 2 is fixedly attached to the rear end of the keyboard chassis (hereinafter simply referred to as the key 1), and the other end is attached to the keyboard chassis 3
Was fixed to. When the tip of the key 1 is pushed down here, the U-shaped leaf spring 2 is deformed along with the stroke and the pushing force of the key 1 becomes heavy, but the U-shaped leaf spring 2 bends at a certain stroke. , It was constructed with the characteristic that the pressing force of the key becomes lighter in the subsequent strokes.

Next, FIG. 5 shows an example in which a metal thin leaf spring and a magnet are used (Japanese Utility Model Publication No. 54-41708). In FIG. 5, a metal leaf spring 4 is fixed to the rear end of the key 1 so that one end is free. On the other hand, a lever 7 rotatably supported about a shaft 6 and having a magnet 5 embedded in a position corresponding to the thin leaf spring 4 and a lever stopper 8 for restricting the movement of the lever when it is rotated by a predetermined amount are provided. Was. When the tip of the key 1 is pushed down, one end of the thin leaf spring 4 fixed to the rear end of the key 1 is attracted to the magnet 5 embedded in the lever 7 and the lever 7 is moved upward with the shaft 6 as a fulcrum. The lever 7 is rotated, and when it is rotated by a predetermined amount, the lever 7 is prevented from rotating by the stopper 8, and the pressing force of the key 1 at the key tip is increased. When the tip of the key 1 is further pushed down, the attraction state of the thin leaf spring 4 and the magnet 5 is broken, the lever 7 falls, and the key 1
It was configured to reduce the pushing force of the.

Next, FIG. 6 shows an example of a combination of thin plates (Jitsuko Sho 57-3718).
No. 2 bulletin). In FIG. 6, a supporting member 11 at one end of a thin plate 10 is fixed to the lower portion of the key 1, while a thin plate is attached to the chassis 12.
A thin leaf spring 9 supporting the other end of 10 is fixed. When the tip of the key 1 is pushed down, the thin plate 10 moves down while deforming the thin plate spring 9 forward. The pressing force of the key was increased until the thin plate 10 became substantially horizontal, and thereafter, the pressing force of the key was decreased.

Problems to be Solved by the Invention FIG. 3 is a pressing-down force-keystroke curve of a piano.
Although there is a change point of the pushing force for pushing up the damper lever from the point O to the point A, the curve is relatively constant regardless of the key stroke. The pressing force sharply increases from point A to point B, and when point B is exceeded, it sharply decreases to point C, and on the contrary, it rises from point C to point D and the key does not go down any further. When the key is raised from the depressed state, the curve returns to point O while maintaining a predetermined amount of hysteresis HA. This A
The characteristic of the piano pressing force-key stroke curve is that the pressing force changes abruptly from point B to point C.

A conventional example will be described in comparison with the piano curve. In the example of FIG. 4, the temporary spring 2 starts to bend immediately after the key 1 is pressed down, and the pressing force increases with the stroke, and becomes maximum immediately before the leaf spring 2 bends. After that, the pressing force was temporarily reduced due to the bending, and when the key 1 was further pressed, the pressing force increased again. As described above, in this embodiment, although the characteristic from the point A to the point C via the point B can be approximated, the flat characteristic from the point O to the point A is not obtained and the bending of the leaf spring 2 is not performed. The points and the pressing stroke of the key 1 are not constant and variations easily occur, and the leaf spring 2
Since it bends, it breaks easily, and it was not satisfactory in terms of durability required by a piano.

Next, an example shown in FIG. 5 was devised. In this example, the lever 7 is moved to the key 1 by the attraction force of the thin leaf spring 4 fixed to the key 1 when the key 1 is pushed down and the magnet 5 embedded in the lever 7. The part that comes into contact with the stopper 8 and the pressing force of the key 1 becomes heavy from the point A to the point B until it comes into contact with the stopper 8 from the point O to the point A of the curve. The curve of the pressing force when pressing the key 1-the key stroke is shown in FIG. 3 such that the part where the pressing force of the key 1 is weakened and the pressing force of the key 1 is weakened corresponds to points B to C. The change was close to the curve of the piano shown in. However, due to the variation in the magnetic force of the magnet, the pressing force at point B tends to vary, making it difficult to play. Alternatively, when the thin leaf spring 4 and the magnet 5 are attracted to each other, a metallic sound is generated, and if a cushioning material for a noise target is inserted, the attracting force becomes weak, which is satisfactory. It wasn't a thing.

Then, the example shown in FIG. 6 was devised next, but this example also has a change characteristic such that the flat characteristic from the O point to the A point does not appear like the example of FIG. 4, and it is not satisfactory. It was

The present invention provides a structure in which the relationship between the pressing force of a key and the key stroke is matched with the characteristics of a piano and the drawbacks of the conventional example are eliminated.

Means for Solving the Problems In order to solve the above problems, the present invention combines a lever device and a key configured so that the operating force decreases with each increase in stroke, and when the key is depressed for a certain stroke. It is configured to come into contact with the lever device.

Action The present invention realizes a characteristic that the pressing force is almost constant up to a certain stroke of the key and a rapid change in the pressing force after hitting the lever, and a characteristic close to a curve of a piano. There is.

Embodiments Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention. In FIG. 1, a weight 18 is embedded in the rear portion of the key 1 whose fulcrum is supported at the center portion, and a resistance corresponding to the pressing force from point O to point A of the curve of the piano in FIG. 3 is provided. ing. Further, a cushioning material 17 made of wool felt or the like is fixed to the rear end of the key 1, and is urged downward by a spring 15 at a certain distance from the key 1 so as to be rotatable about a fulcrum 14. , Lever whose downward rotation is restricted by stopper 16
13 are installed. Looking at the lever device here,
The lever 13 in the non-operating state shown by the solid line receives a downward force by the spring 15 in the solid line position, but considering the downward torque T _A at this position, the force of the spring 15 and the fulcrum 14
Expressed as the product of the distance A from. Next, considering the case where the front end of the key 1 is pushed down to lift the rear end and the lever 14 is set to the position of the dotted line, the torque T _{B in} this case is
It is the product of the force of the spring 15 and the distance B from the fulcrum. If the spring 15 is designed to have a constant force, the torque will be 14
Is proportional to the distance from, and as shown in FIG. 1, by rotating the lever 13 from the solid line to the dotted line, the distance from the fulcrum is set so that A> B. As for the relationship between the torque) and the stroke of the lever, it is possible to make a lever device in which the lever operating force decreases as the lever 13 rotates as shown in FIG.

In FIG. 1, when the front end of the key 1 is pushed down, the pushing force of the key 1 becomes constant until the rear end of the key 1 comes into contact with the lever 13, and from the O point of the curve of the piano shown in FIG. The characteristic between points A is obtained. Then, after the rear end of the key 1 and the lever 13 come into contact with each other, the pressing force of the key 1 rapidly increases to a value corresponding to the lever operating force T _A in FIG. This is the characteristic from point A to point B in FIG. When the key 1 is further pushed down, the pushing force of the key 1 falls to a value corresponding to the lever operating force T _B in FIG. This is the characteristic from point B to point C in FIG. As described above, the curve of the piano shown in FIG. 3 can be faithfully realized. Moreover, since the position of the point A is the position where the key 1 and the lever 13 come into contact with each other, it is easy to manage, and there is little variation.
Since it can be determined by the product of the distance A from 14, the dimensional accuracy of the lever 13 can be improved by using a molded product, and the spring force of the spring 15 can be set to a constant value so that the variation does not easily occur. Therefore, it is relatively easy to make the characteristics uniform, the collision noise is not generated, and there is no excessive use such as bending of the U-shaped spring, so that the life can be extended.

In the embodiment shown in FIG. 1, the key 1 has a fulcrum at the substantially central portion thereof, and the lever device is configured to be driven at the rear end thereof. But of course it is good.

EFFECTS OF THE INVENTION According to the present invention as described above, an excellent keyboard device for an electronic musical instrument is provided which is capable of obtaining the same pressing force-keystroke characteristics as a piano while solving the drawbacks of the conventional example. It can be done.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a keyboard device for an electronic musical instrument according to an embodiment of the present invention, FIG. 2 is a characteristic view of a lever device used in the present invention, and FIG. 3 is a diagram showing the pressing force and key stroke of a piano. FIG. 4, FIG. 5, FIG. 6, and FIG. 6 are characteristic cross-sectional views showing the relationship, which are partial sectional views showing a conventional example. 1 ... Key, 13 ... Lever, 15 ... Spring.

Claims (1)

[Claims] 1. A plurality of keys arranged in parallel for each tone pitch,
A plurality of levers corresponding to the key are provided with a lever device that is actuated from the middle of the pressing stroke of the key, and the operating force characteristic of the lever device is such that the operating force decreases as the stroke of the lever increases. A keyboard device for an electronic musical instrument, which is configured as described above.