JPH0442877Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a keyboard device for an electronic musical instrument such as an electronic piano.

(Prior Art) For example, it is desirable for an electronic piano to have a touch similar to that of an acoustic piano.
Piano touch is characterized by a momentary release of force as the fingers continue to press the keys, giving the player the sensation of inertia, which is difficult to mechanically reproduce. Jitsukō 47-
Various efforts have been made in the past, including the one shown in No. 1561, but since all of them rely only on springs, there is still no known one with a sufficient piano touch.

(Technical Issues) The present inventor has conducted extensive research to solve the above-mentioned problems, and has already filed an application for some of the results. Unlike the conventional method of creating key press characteristics using springs, this method applies a predetermined load in the form of inertia, and since the spring is only used as an auxiliary device, there is no change in the characteristics. , an almost satisfactory touch feeling was obtained. However, as a result of adding mechanisms to create a more distinct piano touch, or systematically studying the shape and materials of the action, springs, etc., it was discovered that the touch could be brought even closer to that of an acoustic piano.

The goal of this invention is to not only provide a feel that is sufficiently similar to that of a piano touch, but also to ensure extremely smooth operation and to not lose the desired performance and characteristics even after repeated use over a long period of time. The purpose is to do so.

(Technical means) In order to solve the above problems, the present invention provides chassis 1
It has a swingable keyboard 3 supported by a keyboard fulcrum 2 at the rear end, a support part 4 on the upper part that supports the keyboard 3 in the middle part, and an arm part 5 for applying a load on the lower part. A swingable action member 7 is attached to the chassis 1 by a fulcrum 6 between the support part 4 and the arm part 5, one end is engaged above the fulcrum 6 of the action member 7, and the other end is engaged with the key fulcrum. The curved spring 8 engaged near 2 and the keyboard 3 are held at the key fulcrum 2.
A plurality of protrusions 10 ₁ , 10 _{2 .} . . are provided at the contact portion between the support portion 4 and the keyboard 3, and the contact position changes before and after the key is pressed.
This method takes the form of forming it in the front-rear direction.

The curved spring 8 is not used for the purpose of pushing up the keyboard 3 or maintaining the position of the keyboard 3.
The position of the keyboard 3 is determined by the action member 7.
The system will be maintained in the same way as for existing applications.
In order to more effectively bring out the characteristics of the action member 7, the keyboard 3 and the support section 4 are arranged to be in point-wise or linear contact with each other through a plurality of protrusions 10 ₁ , 10 ₂ .

(Example) A detailed explanation will be given below using illustrated embodiments.

Each keyboard 3 is supported by the chassis 1 at a fulcrum 2 at its rear end so that keys can be depressed, and is also supported by an action member 7 at an intermediate portion thereof. The keyboard fulcrum 2 consists of a substantially U-shaped concave groove 11 formed laterally at the rear end of the keyboard, and a support shaft 12 projecting in an inverted L shape from the rear end of the chassis, and supports the fulcrum 6 of the action member 7.
consists of a recess 13 formed on the front side thereof and an edge 14 of a hole 15 formed in the chassis 1 for attaching the member. The support part 4 of the action member 7 that supports the keyboard 3 protrudes above the fulcrum 6, and an arm part 5 that applies a load to the action member 7 is provided at the lower part, and a weight 16 is provided at the part extending forward. . Note that the push-up load may be obtained by selecting the material of the action member 7 without using the weight 16. Further, the load can be adjusted by selecting the weight 16 and by changing the length of the arm portion 5.

The curved spring 8 of the embodiment is a leaf spring, and both ends engage with receiving portions 17 and 18 formed near the fulcrum of the keyboard 3 and above the fulcrum 6 of the action member 7, respectively.
The receiving portion 18 is mounted in an upwardly curved state, and the receiving portion 18 has an oblique side 18a on the upper side. 19 indicates a spring holder. The support part 4 that supports the keyboard 3 is located between both fulcrums 2 and 6, and the one in the embodiment has two protrusions 10 ₁ and 1.
0 ₂ , and only one protrusion 10 ₁ is in contact with the slope 21 of the pedestal 20 provided on the underside of the keyboard when the key is not pressed. The other protrusion ₁₀₂ changes after the key is pressed,
The space between them serves as a grease reservoir 22. The structure of this support part 4 may be such that some or all of the protrusions 10 ₁ and 10 ₂ are provided on the side of the pedestal 20, as shown in FIGS. 2a, b, and c, and the effect is the same. . Also, the number is 2
Not limited to individuals.

In the figure, 23 is a damper that gives a feeling of pressing a key, 24 is a stop that provides a cushioning effect when the action member 7 returns, 25 is a guide piece at the front end of the keyboard, and 26 is a stop that engages with it and positions each keyboard 3. shows.

The action member 7 has an actuation piece 2 protruding from the rear end.
The input section is connected to an electrical input section at 7, and the input section has a contact piece 29 whose base end is fixed to the base 28, whose tip end is brought into elastic contact with the actuating piece 27, and contacts 30, 3.
Bus bars 32 and 33 are provided as electrodes of the contacts 30 and 31 in the movement range of 1, and changes such as pianissimo→fortissimo are taken out. Note that 34 is keyboard 3
The cushioning material 35 between the chassis 1 and the chassis 1 is a black key, which is also attached by the device constructed as described above. In order to stabilize the keyboard 3 at the fulcrum 2, the pressing spring 9 is connected to a locking portion 36 at the lower part of the rear end of the keyboard and to the chassis 1.
The line of force is indicated by g. G indicates the rear end of the curved spring 8 (receiving portion 1
7) and the fulcrum 6 of the action member 7, and what is indicated by G' is the repulsive force line of the curved spring 8 that connects the rear end (receiving portion 17) and the receiving portion 18. The line indicated by G does not move, but it is the repulsive force line of the curved spring 8.
G' and the line of force g move up and down depending on the key press.

(Function of the device) In the above configuration, when the keyboard 3 is at the top dead center and stationary, the protrusion 10 ₁ protruding from the support portion 4 of the action member 7 as shown in FIG. It is in contact with the slope 21 of the stand 20 at point X. The mechanical state in this case is shown in FIG. 6, and the force for pushing up the keyboard 3, _W1, is expressed by the following equation.

W ₁ =W ₀・AD ₁ /BE... When the keyboard 3 is pressed down, the action member 7 is pressed down at the point As shown in _{FIG .}
But at that moment, a slight shock occurred,
At the next moment, point X is separated and the keyboard 3 comes into contact with the action member 7 only at point Y (FIGS. 5 and 8). At this time, the force _W3 that pushes up the keyboard 3 at the key pressing point is expressed by the following equation.

W ₃ = W ₀・AD ₃ /CE...The distance B from the fulcrum 6 to the first protrusion ₁₀₁ is the second
Since the distance D ₁ from the keyboard fulcrum 2 to the first protrusion 10 ₁ is set to be larger than the distance C to the protrusion 10 ₂ and smaller than the distance D ₃ to the second protrusion 10 ₂ , the formula Therefore, W ₃ > W ₁ … is obtained. The change characteristic curve of the key pressing force W ₁ to _{W 3} is as shown in Fig. 12, and the intermediate pressing force W ₂
This shows that the change is from W ₁ to W ₃ in a short period of time. This characteristic corresponds to the load on the action member.
W ₀ can be arbitrarily set by changing the dimensions around the fulcrums 2 and 6.

Next, the action of the curved spring 8 will be explained. In the above configuration, when the keyboard 3 is at the top dead center and stationary, a repulsive force _F1 is generated along the repulsive force line G' of the spring 8 as shown in FIG. The rotational force M ₁ in the direction of arrow A acting on the spring receiver 18 at a distance r from the fulcrum 6 is generated by the distance r from the fulcrum 6 and the component force f ₁ , and pushes the keyboard 3 via the action member 7 . Acts as a rotating force in the upward direction.

When the keyboard 3 is pressed down, the action member 7 connected by the support portion 4 also rotates counterclockwise in FIG. 10 against the elasticity of the spring 8. At this time,
At the fulcrum 6 of the action member 7, a force _F2 is generated along the repulsive force line G' of the spring 8, but since it passes through the fulcrum 6, it is treated as an internal stress within a distance r from the fulcrum 6, and no external force is generated. .

When the keyboard 1 is further pressed down, the spring receiver 18
As soon as the point of action on the spring 8 moves downward from the line G passing through the base end receiving part 17 and the fulcrum 6, the direction of action of the spring 8 is reversed (Fig. 11), so the pressing force on the keyboard 3 suddenly decreases. . This is because the repulsive force line G' whose base end is the base end receiving part 17 along which the force F ₃ is generated along the repulsive force line G' of the spring 8 passes below the fulcrum 6,
A line G through which the tip receiving portion 18 passes through the proximal receiving portion 17 and the fulcrum 6
This is because by moving further downward, a rotational force M ₃ in the direction of arrow B is generated due to r and f ₃ . This rotational force
M ₃ changes depending on the rotation angle θ of the distance r to the receiving portion 18. Changes in the force applied to the weight of keys pressed on keyboard 3,
The characteristic curve is shown in FIG. Said twelfth
The support part 4, the receiving parts 17 and 18 at both ends of the spring, the fulcrum 6 and the receiving part 18 are arranged so that the change in the key pressing force shown in the figure, that is, the change in the weight of the pressed key, and the change given in FIG. 13 are synchronized. By appropriately setting the distance r between them, etc., the change characteristics shown in FIG. 14 can be dynamically synthesized. The characteristic curve shown in FIG. 14 closely approximates that of an acoustic piano.

Regarding the electrical connection, when the actuating piece 27 pushes down the contact piece 29 by the action member 7, the bus bar 3
The length of time for the contacts 30 and 31 to pass between 2 and 33 appears as a change in volume.

(Effect of the invention) Therefore, according to the invention, a pushing force is applied to the keyboard 3 by the weight of the action member 7, and the operating feel when operating the keys is corrected by the curved spring 8, so that the feel is very similar to that of a piano touch. The mechanism for this purpose is very simple as it only has a single spring 8, and the keyboard 3 and the action member 7 that applies a load to it are in contact with each other through a plurality of protrusions 10 ₁ and 10 ₂ . As a result, the frictional resistance is extremely small, and the changes in key press force are mechanically rational, so it is directly felt by the performer, and the effect is that it maintains the desired performance even after repeated use over a long period of time. There is.

[Brief explanation of the drawing]

The drawings show a keyboard device for an electronic musical instrument according to the present invention, and FIG. 1 is a longitudinal cross-sectional view of one embodiment, and FIG. 2 shows a plurality of protrusions. 3, 4, and 5 are side views of point modifications; FIGS.
Figures 7 and 8 are mechanical state diagrams that explain the mechanical relationships of each part with a focus on the action of the support part, Figures 9 and 1.
0 and 11 are explanatory diagrams of the action of the curved spring 8, and the first
Figure 2 is a characteristic curve diagram showing changes in key pressing force, the first
FIG. 3 is a characteristic curve diagram showing changes in force applied to key depression weight, and FIG. 14 is a characteristic curve diagram combining FIGS. 12 and 13. DESCRIPTION OF SYMBOLS 1... Chassis, 2... Keyboard fulcrum, 3... Keyboard, 4... Support part, 5... Arm part, 6... Fulcrum, 7... Action member, 8... Curved spring, 9
...Press spring, 10 ₁ , 10 ₂ ...Protrusion.

Claims (1)

[Scope of utility model registration request] The chassis 1 has a swingable keyboard 3 supported by a keyboard fulcrum 2 at the rear end, a support part 4 at the upper part that supports the keyboard 3 at an intermediate part, and an arm part 5 that loads the load at the lower part. The device itself has a swingable action member 7 attached to the chassis 1 by a fulcrum 6 between the support part 4 and the arm part 5, one end of which engages above the fulcrum 6 of the action member 7, and the other end It is equipped with a curved spring 8 that engages near the key fulcrum 2 and a pressing spring 9 that presses the keyboard 3 against the key fulcrum 2, and a contact point is provided at the contact portion between the support portion 4 and the keyboard 3 before and after the key is pressed. A plurality of switching protrusions 10 ₁ , 1
0 ₂ ... is formed in the front-rear direction of the keyboard 3. A keyboard device for an electronic musical instrument.