JPH0549240B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a key device for electronic musical instruments, particularly electronic pianos.

(Prior Art) Conventionally, as shown in Fig. 10, keys for electronic pianos have been equipped with a suitable weight on the top surface or inside of the end.
A ₁ , a ₂ , and a ₃ are provided to obtain the static characteristics of the load with respect to the key stroke as shown in Figure 11, that is, the characteristics that approximate the static characteristics of a piano as shown in Figure 9. It has been known.

(Problems to be Solved by the Invention) The keys of the conventional electronic piano described above provide a feel that is relatively similar to the touch of a piano key, but the reaction of the action may still vary depending on the strength of the key strike on a piano. The dynamic characteristics are still unsatisfactory, such as the fingers not being able to feel changes in force. That is, in terms of dynamic characteristics, the keys of a conventional electronic piano have characteristics as shown in FIG. 11, which are significantly different from the dynamic characteristics of a piano as shown in FIG.

SUMMARY OF THE INVENTION An object of the present invention is to provide a key device for an electronic musical instrument that provides a feel more similar to the touch of a piano key than conventional devices.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention fixes a weight to the free end of a leaf spring, one end of which is fixed to the rear part across the fulcrum of the key. A cushion material is placed on the key to suppress the movement of the weight between the rear part of the key and the fulcrum of the key, and between the weight and the main body of the instrument such as a shelf, the weight comes into contact with the main body of the instrument such as a shelf when the key is pressed. A cushion material is provided to suppress the movement of the weight, and a U-shaped leaf spring is placed on one side of the top or bottom surface of the key and the main body of the instrument such as a shelf, and a rectangular parallelepiped member made of a friction material is placed on the other side. are fixed so that the sliding surfaces of the keys are perpendicular to the longitudinal direction of the key, and both ends of the U-shaped leaf spring come into pressure contact with the surfaces of the rectangular parallelepiped member and slide when the key is pressed and returned. It is characterized by what it did.

(Function) In the piano, the action mechanism interposed between the key A and the hammer B includes a cushion material such as felt and a spring, so as shown in Figure 4, a spring K with a spring constant k ₂ It can be approximated as ₂ . Also, finger c is a spring with spring constant k ₁ .
Since it can be approximated as K ₁ , when key A is pressed down with finger c, it can be considered that force acts on key A via spring K ₁ .

Therefore, the hammer B is a weight M ₂ of mass m ₂ ,
If key A is represented as a weight M ₁ with mass m ₁ , finger c
The striking mechanism of the piano keys when key A is pressed down can be shown as shown in FIG.

Now, when key A is pressed down with finger c at speed v ₀ , the equation of motion is: However, x ₁ and x ₂ are the movements of weights M ₁ and M ₂ , respectively.

Solving equation (1) and finding the force F(t) applied to finger c, we get F(t)=k ₁ x ₁ =A ₁ k ₁ cos(ω ₁ t+3/2π)+B ₁
k ₁ cos(ω ₂ t+3/2π)……(2) Here, A ₁ =(ε ₂ −1)/(ε ₂ −ε ₁ )ω ₁・V ₀ B ₁ =(ε ₁ −1)/ (ε ₁ −ε ₂ )ω ₂・V ₀ ε ₁ = k ₂ /k ₂ −m ₂ ω ₁ ² ε ₂ = k ₂ /k ₂ −m ₂ ω ₂ ² To illustrate equation (2), the magnitude of the speed V ₀ is 1.0 to 2.0.
m/sec (Fuorte f), 0.5 to 1.0 m/sec (Mezzo Fuorte mf), 0.3 to 0.5 m/sec (Mezzo Piano MP), 0.05
When each key is pressed at ~0.3 m/sec (piano p), the key pressing force with respect to the key stroke is as shown in the sixth figure.

This characteristic is similar to the measured dynamic characteristic of the piano shown in FIG. 7, and it can be seen that the above-mentioned approximation is valid.

Therefore, if the keys of an electronic piano can be approximated as shown in Figure 5, it will be possible to obtain a tactile sensation similar to that of a piano when pressing the keys.

In the present invention, the leaf spring having one end fixed to the key and a weight fixed to the other end is spring K ₂ in FIG.
, and the weight is equivalent to weight M ₂ , so
By pressing the keys configured in this way with your fingers, you can obtain a key touch similar to that of a piano.

The cushion material interposed between the weight and the key suppresses the movement of the weight and prevents the unstable position of the weight from adversely affecting the key touch. The cushion interposed between the weight and the key can suppress the movement of the weight whether or not there is a gap between the weight and the key. Further, this cushion may have a multilayer structure as required. In addition, the cushion material that comes into contact with the key when the key is pressed and suppresses the movement of the weight prevents the weight from jumping up and making its position extremely unstable, which would adversely affect the touch of the key. It acts to prevent damage, and when the key is pressed, the weight is sandwiched between the cushion material interposed between the weight and the key, stopping the vibration of the weight and preventing any negative impact on the key touch. do. In addition, a U-shaped plate spring is fixed to the top or bottom of the key, for example, to one side of the shelf board, and a rectangular parallelepiped member made of friction material is fixed to the other side. Since both ends of the leaf spring slide in pressure contact with the surfaces of the rectangular parallelepiped member, when the key is returned, a key stroke load characteristic, that is, a key touch, which is closer to that of a piano than to a conventional electronic musical instrument is obtained.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the invention.

In FIG. 1, 1 is a key, and one end of a leaf spring 3 is fixed to the upper surface of the rear part (on the right side of the figure) sandwiching the fulcrum of the key through a seat piece 2, and the other end of the leaf spring 3. A weight 4 is fixed to the upper surface of the. Further, a cushion material 5 is bonded to the upper surface of the key 1 corresponding to the weight 4, and the cushion material 5 is substantially bonded to the leaf spring 3 when the key 1 is at rest. 6 is fixed to a key stopper 8 fixed to the shelf board 7, and the key 1
This is the cushion material that the weight 4 comes into contact with when pressed.

In FIG. 1, reference numeral 9 denotes a U-shaped leaf spring fixed to the lower surface of the key 1, and a rectangular parallelepiped member 10, at least a part of which is made of a friction material, has both ends fixed to the shelf board 7. It is in pressure contact with a surface and slides on the surface when the key 1 is pressed and when the key 1 is returned to generate a frictional force that does not change depending on the position of the key 1, the pressing speed of the key 1, and the weight of the leaf spring 9, The touch feeling when returning the key 1 is made to be more similar to that of a piano than the conventional one. Reference numeral 11 indicates a switch that closes when key 1 is pressed to activate a circuit for producing sound (not shown), and 12 indicates a keyboard pillow made of cushion material.

As shown in the third figure, one end of the leaf spring 3 may be directly fixed to the lower surface of the rear part (on the right side of the figure) that holds the fulcrum of the key 1. In this case, the other end of the leaf spring 3 A weight 4 fixed to the upper surface is formed in an L shape so as to face from the end surface to the upper surface of the key 1, and a cushion material 5 is bonded to the upper surface of the key 1 facing the weight 4. In FIG. 3, the rectangular parallelepiped member 1
0 is attached to a support member 13 fixed to the key stopper 8. The embodiment shown in the third figure works similarly to the one shown in the first figure, but since the tip of the leaf spring 3 protrudes from the front end of the key 1, it can be made shorter than the key 1 shown in the first figure. Furthermore, since the U-shaped leaf spring 9 can be fixed to the top surface of the key 1, the leaf spring 9 has the advantage that it is not deformed when the key 1 is mounted on the shelf board 7, compared to the one shown in the first figure. There is.

To give a specific example in which good characteristics were obtained in the embodiment shown in the first diagram, the leaf spring 4 has a length of 50 to 150 mm.
mm, thickness 0.5 to 2 mm, and weight 4 was 20 to 100 g.

(Effects of the Invention) As explained above, according to the present invention, the dynamic characteristics of the load with respect to the key stroke are similar to those of a piano with a simple structure, and the static characteristics of the load with respect to the key stroke when returning the key are similar to those of a piano. An approximation can be easily obtained irrespective of key position, leaf spring weight, and key depression speed, resulting in a key touch that more closely resembles a piano key touch than a conventional electronic musical instrument. In addition, when attaching a U-shaped leaf spring to the instrument body, the spring can be connected to multiple keys, and when attaching a sliding contact member to the instrument body, the sliding member can be connected to multiple keys, etc. It has the effect of

[Brief explanation of drawings]

Fig. 1 is a side view of one embodiment of the present invention, Fig. 2 is a perspective view of its main parts, Fig. 3 is a side view of another embodiment of the invention, and Figs. 4 and 5 are pianos. An explanatory diagram for analyzing the key touch of Figure 9 is a side view of a conventional electronic piano key device, Figure 10 is a static characteristic diagram of key stroke vs. load, and Figure 11 is a static characteristic diagram of key stroke vs. load of a piano. It is a dynamic characteristic diagram. 1...key, 3...leaf spring, 4...weight, 5,
6...Cushion material, 9...U-shaped leaf spring, 1
0... Rectangular parallelepiped member.

Claims (1)

[Claims] 1 A weight is fixed to the free end of a leaf spring with one end fixed to the rear part across the fulcrum of the key, and a cushion material that suppresses the movement of the weight is placed between the weight and the rear part across the fulcrum of the key. Between the weight and the main body of the instrument such as a shelf board, a cushion material is provided that contacts the weight when the key is pressed and suppresses the movement of the weight, so that the upper or lower surface of the key and the shelf board etc. A U-shaped leaf spring is fixed to one side of the musical instrument body, and a rectangular parallelepiped member made of friction material is fixed to the other side so that the sliding surface of the leaf spring is perpendicular to the longitudinal direction of the key. A key device for an electronic musical instrument, characterized in that both ends of a U-shaped leaf spring slide in pressure contact with the surface of a rectangular parallelepiped member when the key is pressed and returned.