JPH0664453B2 - 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.

2. Description of the Related Art In recent years, electronic keyboard musical instruments have been improved so that they can reproduce musical performances similar to those of acoustic pianos. In terms of sounds, many of them are touch-sensitive methods that control the generated sound according to the strength of keystrokes, and can produce that strength It has become to. Along with this, the touch feeling of the key transmitted to the player's finger is emphasized, and it has been strongly desired to realize a keyboard device for an electronic musical instrument that can provide a touch close to that of a piano.

As a conventional technique for realizing such a keyboard for an electronic musical instrument, as shown in, for example, Japanese Utility Model Publication No. 50-10752, a calculus or an electromagnet is attached to the lower surface of the keyboard, and an electromagnet is mounted on a frame facing the keystone. Alternatively, there is a keyboard device for an electronic musical instrument in which a slab is provided and the touch of the keyboard is controlled by the magnetic force between the slab and the electromagnet.

Hereinafter, the conventional keyboard device for an electronic musical instrument as described above will be described with reference to the drawings.

FIG. 4 shows the structure of a conventional keyboard device for an electronic musical instrument. In FIG. 4, reference numeral 1 denotes a keyboard, one end of which is rotatably supported by a support plate 3 provided at the end of the frame 2, and between the end of the keyboard 1 and the lower part of the support plate 3, A coil spring 4 is provided. Reference numeral 5 denotes a permanent magnet fixed to the lower surface of the central portion of the keyboard 1, and an electromagnet including a pole piece 6 and an exciting coil 7 is attached to the frame 2 so as to face the permanent magnet 5. Both ends 8 of the exciting coil 7,
A DC power supply 11 is connected to 9 via a magnetic switching switch 10.

Regarding the keyboard device for electronic musical instruments configured as described above,
The operation will be described below.

When the performer strikes the keyboard 1, the keyboard 1 is rotatably supported by the support plate 3, so that it resists the tension of the coil spring 4 provided between the end of the keyboard 1 and the lower portion of the support plate 3. , The keyboard 1 descends. A permanent magnet 5 is fixed to the lower surface of the central portion of the keyboard 1, and an electromagnet composed of a magnetic pole piece 6 and an exciting coil 7 is attached to the frame 2 so as to face the permanent magnet 5. The distance between the magnet 5, the pole piece 6 and the electromagnet including the exciting coil 7 becomes narrower. Since the DC power source 11 is connected to both ends 8 and 9 of the exciting coil 7 via the polarity switching switch 10, the touch of the key can be controlled by operating the polarity switching switch 10. That is, when the polarity switching switch 10 is off, no current flows through the exciting coil 7, the magnetic pole piece 6 does not operate as an electromagnet, and the permanent magnet 5 provided on the lower surface of the central portion of the keyboard 1 does not have the magnetic pole piece 6. Because it is attracted to, the touch of the key is a little light. On the other hand, when the polarity switching switch 10 is turned on, a current flows through the exciting coil 7 to generate an electromagnetic force, and the pole piece 6 operates as an electromagnet. Pole piece 6
The polarity of the electromagnet generated at 1 can be selected according to the direction of the current flowing through the exciting coil 7. That is, the polarity can be determined by operating the polarity switching switch 10. Keyboard 1
When the polarities generated in the magnetic pole pieces 6 are different from the polarities of the permanent magnet 5 provided on the lower surface of the magnets, they attract each other.
The keyboard 1 is strongly pulled to the lower side,
It can be quite light. In addition, by operating the polarity switching switch 10,
When the polarities generated in the pole pieces 6 are the same, they repel each other and the touch of the key becomes heavy.

As described above, the permanent magnet 5 provided on the lower surface of the keyboard 1 and the pole piece 6 and the exciting coil 7 are attached to the frame facing the permanent magnet 5, and the polarity changing switch 10 is provided between the coil ends 8 and 9 of the exciting coil 7. The keyboard device for an electromagnetic musical instrument has a configuration in which a direct current power source is connected to the touch panel and various touch feelings can be obtained by operating the polarity switching switch 10.

Problems to be Solved by the Invention FIG. 3 shows the reaction force received from the keyboard, that is, the touch feeling, which the finger receives from the keyboard in the key-pressing process from the touch of the finger to the descent of the keyboard to the stop until it stops. It is measured on a grand piano, and the horizontal axis represents the movement stroke of the keyboard and the vertical axis represents the reaction force. Looking at the above characteristics, the reaction force that the finger receives from the keyboard is the reaction force that occurs when the finger touches the keyboard (hereinafter referred to as the attack reaction force), and the reaction force that occurs when the hammer moves (hereinafter referred to as the hammer movement reaction force). Call)
It can be roughly divided into three types, the reaction force generated when stopped by a stopper (hereinafter referred to as the stop reaction force). If this is expressed by the touch feeling on the finger, the attack reaction force is felt as an impact force, and the speed of the player's finger, that is, the playing style, is also greatly affected, and the stronger the pitch, the greater the impact. Next, the hammer movement reaction force is generally expressed as heavy or light, and is a characteristic peculiar to an acoustic piano that produces a sound by striking the hammer string. It is also the main factor that causes the difference. The stop reaction force is perceived as an impact force like the attack reaction force, and its magnitude depends on the keystroke speed.

As is clear from the above characteristics, it is necessary to control the movement of the keyboard in a complicated manner in order to give the touch feeling of the piano.
Therefore, it has been difficult to obtain the touch feeling of the acoustic piano with the above-mentioned conventional configuration in which the movement of the keyboard is simply controlled by the polarity changeover switch.

Further, in the above-mentioned conventional example, since the movement of the keyboard is controlled by the magnetic force between the permanent magnet and the electromagnet, when the gap between the permanent magnet and the electromagnet is large, that is, the keyboard in which mutual magnetic force is difficult To control the movement of the keyboard near the fully-up position, use a permanent magnet with a large shape and large magnetomotive force, and take measures such as passing a large current through the exciting coil as an electromagnet to reduce the magnetic force. It had to be large enough for control. However, enlarging a permanent magnet
Since the dimensions between the keyboards are fixed, it is difficult in terms of space, and if a magnet material with a large magnetomotive force is used, it becomes very expensive, resulting in a significant cost increase. On the other hand, in order to strengthen the magnetic force of the electromagnet, passing a large current through the exciting coil requires a large power output as a power source and causes damage to the exciting coil due to heat generation, which is not practical. It was

In view of the above problems, the present invention provides a keyboard device for an electronic musical instrument, which is very close to the touch feeling of an acoustic piano and is low in cost.

Means for Solving the Problems In order to achieve this object, a keyboard device for an electronic musical instrument of the present invention has a connecting plate connected to the lower surface of a keyboard that is rotatably held around a fulcrum, and one end of the connecting plate is connected to the connecting plate. A piston made of polyester elastomer and having a connecting rod with two constricted parts integrated was fixed and inserted into the dash pot, and a fine hole was provided at the end of the dash pot, and a fine hole outlet was provided at the fine hole outlet. An air valve composed of a piezoelectric, electromagnetic or electrokinetic actuator is arranged, and the air valve is provided with a control circuit for electrically controlling its movement.

Operation With this configuration, the keyboard is connected via a connecting plate to a piston that is made of polyester elastomer and has a connecting rod with two constrictions. , The connecting part of the connecting plate and the connecting rod of the piston makes a rotational movement about the fulcrum of the keyboard, but the two constricted parts of the connecting rod absorb this movement and the movement of the piston is moved to the dashpot wall surface. It is parallel to and reduces mechanical friction to obtain smooth movement. Further, since a fine hole is provided at the end of the dashpot and an air valve whose movement can be electrically controlled by a control circuit is provided at the fine hole outlet, for example, an air valve is used to When the player presses the keyboard, the air in the chamber consisting of the dashpot and the piston expands, and the keyboard is braked against the movement of the finger, resulting in a touch feeling. Will be very heavy. On the other hand, by controlling the air valve to open the dashpot pores that were closed until then, air can easily flow in and the air in the vacant chamber hardly expands, and a very light touch feeling can be realized. . In this way, the electric pressure in the dashpot is changed by the electrical control of the pores provided at the end of the dashpot and the air valve provided at the exit of the pore, so that any key touch feeling can be realized.

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

FIG. 1 is a cross-sectional view of essential parts showing the configuration of a keyboard device for an electronic musical instrument according to an embodiment of the present invention. FIG. 2 shows an enlarged cross section of the main part. In FIG. 1, reference numeral 12 is a keyboard, 13 is a supporting base for rotatably supporting the keyboard 12, 14 is a substrate for fixing the supporting base 13, 15 is a coil spring provided between the keyboard 12 and the substrate 14, 16 Is a connecting plate connected to the underside of the keyboard 12, 17
Is an opening for passing the connecting plate 16 provided on the substrate 14, and 18 is made of polyester elastomer, and has two constricted portions 19,2.
The connecting rod 21 having 0 is an integral piston, and the connecting rod 21 and the connecting plate 16 are fixedly connected. 22 is a piston
One end 23 of the dashpot into which 18 is inserted is fixed to the substrate 14. 24 is a fine hole provided at the end of the dash pot 22, 25 is an air valve of a piezoelectric actuator provided at the outlet of the fine hole 24 with one end fixed to the dash pot, and 26 and 27 are electric input terminals of the air valve 25. , 28 are control circuits connected to the electric input terminals 26, 27.

The operation of the keyboard device configured as described above will be described below. First, when the performer strikes a key on the keyboard 12, one end of the keyboard 12 is rotatably supported by the support base 13, so that the keyboard 12 is lowered against the spring force of the coil spring 15 provided between the keyboard 12 and the substrate 14. To do. A connecting rod 21 having two constricted portions 19 and 20 on the lower surface of the keyboard 12 via a connecting plate 16.
A piston 18 integrally formed with the piston 18 is coupled and inserted into the dashpot 22. The movement of the connecting rod 21 formed integrally with the piston 18 and the two constricted portions 19 and 20 thereof is very important. That is, the connecting rod 21 of the connecting plate 16 and the piston 18
The connecting part with and produces a rotational movement about the fulcrum of the support base 13 of the keyboard 12, but two constricted parts 19, 20 of the connecting rod 21.
Acts as a fulcrum that bends easily, absorbs rotational movement,
The movement of the piston 18 is converted into a direction parallel to the wall surface of the dashpot 22 to reduce mechanical friction and enable smooth movement. Further, since the polyester elastomer used as the material of the connecting rod 21 itself has an appropriate internal loss, it is possible to absorb unnecessary vibration.

Furthermore, a pore 24 is provided at the end of the dashpot 22,
Since the air valve 25 of the piezoelectric actuator whose movement can be electrically controlled by the control circuit 28 is provided at the outlet of 24, the air valve 25 causes the control circuit 28 to close the outlet of the pore 24. When an electric input is applied by, the air in the empty chamber formed by the dashpot 22 and the piston 18 expands, the movement of the piston 18 is damped, and transmitted to the keyboard 12 connected by the connecting plate 16 to move the finger. However, the touch feeling is extremely heavy.

On the other hand, in the present embodiment, since the air valve 25 is an actuator constituted by a bimorph type piezoelectric element, the electric input from the control circuit 28 applied to its electric input terminals 26, 27 causes the air valve 25 to move as shown in FIG. The outlet of the pore 24 of the dashpot 22 that has been closed until then can be bent and deformed in the opening direction. In this state, when the keyboard 12 is tapped, the air easily flows in through the pores 24, and the air in the chamber consisting of the dashpot 22 and the piston 18 hardly expands.
The 12 movements are unbraked and have a very light touch. In the above two examples, the case where the extreme control is performed has been described, but the movement of the air valve 25 is further finely controlled by the control circuit 28 to adjust the air flow rate flowing from the pores 24 of the dashpot 22. Then dash pot
By changing the air pressure of the vacant chamber constituted by 22 and the piston 18, the movement of the keyboard 12, that is, the touch feeling transmitted to the finger can be made arbitrary.

In this embodiment, the piezoelectric actuator is used as the air valve, but the air valve may be constituted by an electromagnetic or electrodynamic actuator.

EFFECTS OF THE INVENTION According to the present invention, a piston having a connecting rod having two constricted portions inserted into a dashpot is integrated with a lower surface of a keyboard rotatably held around a fulcrum via a connecting plate. The two constricted portions absorb the rotational movement of the connecting portion between the connecting plate and the piston connecting rod to smooth the movement of the piston, and a fine hole is provided at the end of the dashpot to make it fine. An air valve is placed at the hole outlet and its movement is controlled by electrical input from the control circuit to adjust the air flow rate from the dashpot pores and change the air pressure in the chamber formed by the dashpot and piston. It is possible to obtain an arbitrary touch feeling, and it is possible to easily obtain a complicated characteristic such as a hammer movement reaction force, and a keyboard device for an electronic musical instrument that is very close to the touch feeling of an acoustic piano. Can be realized. Further, as in the conventional example, in order to control the movement of the keyboard, the means utilizing the magnetic force between the permanent magnet and the electromagnet can obtain an effective force in order to obtain an effective force. However, in the present invention, a slight movement of the air valve causes air to flow into the pores provided at the end of the dashpot. Only by changing the flow rate, sufficient force for braking the keyboard can be obtained, and there are few components that cause cost increase, so it is possible to make a keyboard for a practical and low-cost electronic musical instrument. .

[Brief description of drawings]

FIG. 1 is a sectional view of a main part showing a configuration of a keyboard device for an electronic musical instrument according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the same part.
FIG. 3 is a keystroke characteristic diagram of a grand piano, and FIG. 4 is a sectional view of essential parts showing a configuration of a conventional keyboard device for an electronic musical instrument. 12 ... keyboard, 16 ... connecting plate, 18 ... piston, 19,20 ...
… Constricted part, 21 …… Connecting rod, 22 …… Dashpot, 24
...... Pore, 25 ...... Air valve, 28 ...... Control circuit.

Claims (2)

[Claims] 1. A keyboard rotatably held around a fulcrum, a connecting plate connected to the lower surface of the keyboard, and a connecting rod made of polyester elastomer at one end of the connecting plate and having constricted portions at two places are integrated. And a dashpot for moving up and down the piston having a pore at the end, an air valve provided so that the outlet of the dashpot pore can be opened and closed, and movement of the air valve A keyboard device for an electronic musical instrument, comprising: 2. The keyboard device for an electronic musical instrument according to claim 1, wherein the air valve is a piezoelectric, electromagnetic or electrodynamic actuator.