JPS5937594A - Key driver for automatic performance piano - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a key drive device for a player piano, which controls the position of an electromagnetic plunger during driving to effectively reproduce soft-tone performances.

In general, player pianos are equipped with a key drive device that automatically drives the keys using electrical signals obtained by reproducing all pre-recorded electrical signals1.This key drive device generally includes an excitation coil and an electric signal. A well-known electromagnetic plunger is used, which is composed of a movable iron core that is slidably disposed in the center of the excitation coil with a small gap, and a yoke that accommodates the excitation coil and forms a complete magnetic path. It is configured to transmit the movement of the movable iron core to the key.

However, since conventional key drive devices of this kind are always fixed to a fixed part of the device such as a shelf board, it is difficult to perform faithful playback. In other words, a key sensor normally detects and records the keystroke speed during recorded performance, and this recorded signal is reproduced during playback performance and used as an electric signal to drive the electromagnetic plunger. If the driving force is extremely small, the hammer may not hit the strings. Therefore, it is conceivable to amplify the electric signal and increase the plunger driving force, but in that case, there is a problem that all the sounds will not be faithfully reproduced. In addition, especially in special playing techniques such as staccato and fast but weak consecutive hits,
Since the movement of the key and the movement of the hammer are different, simply detecting the keystroke information and driving the electromagnetic plunger quickly and intermittently will not be able to faithfully reproduce the strength and timing of the strings struck by the hammer. No.

This invention was made in view of the points mentioned above.
To provide a key drive device for a player piano, which changes the distance between a string and a hammer by moving an electromagnetic plunger toward and away from a key during playback, thereby reproducing weak notes more faithfully and accurately.

Hereinafter, this invention will be explained in detail based on embodiments shown in the drawings.

FIG. 1 is a side sectional view of an action mechanism section showing an embodiment of a grand automatic performance piano equipped with a key drive device according to the present invention. In the same figure, is there a keyboard on shelf 1 of the piano? &2 is placed, and on top of that are a plurality of (for example, 88) keys 4 corresponding to each pitch of the string 3.
are arranged parallel to each other so as to be able to freely swing in the vertical direction centering on their respective intermediate portions.

The keyboards I & 2 are board-mae 5. Yokochu 6. 7. The key Im is formed in a lattice shape by the keys 8, etc., and a unique number of oval key pins 9 and balance key pins 10 are planted on the -L side of the board front 5 and the key 6, respectively, corresponding to each key 4. It's awned. The upper end of the oval key pin 9 always resides in the four parts provided on the lower surface of the front end of the key 4, thereby regulating the rotation of the key 4 in the left and right direction.
The key 4 is supported so as to be able to freely swing downward by a hole 4 that can pass through a long hole 11 provided in the middle of the key 4.

Then, due to the load of the action mechanism 13 (to be described later), the front end 4a normally lifts up from the front plate 5, and the rear end 4b
is placed on the upper surface of the board cutout 7 via the felt 12, and maintains the initial position.A plurality of key sensors 20 are arranged on the upper surface of the front end of the keyboard reed 2, corresponding to the six keys 4. It is set up.

These keysenners 20 detect the name of the pressed key when recording a performance, detect the sound stop timing, convert it into a digital signal, and send this signal to the data recorder (
(not shown), and is usually a fixed contact 21
and the movable contact plate 22 constitute a break contact, which is broken when the key 4 is pressed. Then, when the key press operation reserve 4 returns to the upward position, the movable contact plate 22 contacts the fixed contact 21 again and makes contact, and each time the time from the break point to the make point (sound stop timing) is detected, , the key press time of the key 4 can be detected.

A guide plate 25 is arranged on the I end face of the shelf board 1 and extends westward to all the keys 4, and on the surface of this guide plate 25, a plurality of nb+ electromagnetic plungers 26 are arranged for each of the six keys 4. They are arranged so that they can move up and down, respectively. Each electromagnetic plunger 26 includes a solenoid coil 28 wound around the outer periphery of a bobbin 27, a yoke 29 that houses the solenoid coil 28, a movable iron core 30 loosely inserted into an inner hole of the bobbin 27, and a movable iron core 30 that is loosely inserted into an inner hole of the bobbin 27. It is constituted by a spring 32 etc. that elastically supports the iron core 30 and brings the push-up button 31 into light contact with the lower surface of the rear end of the key 4.
A flat sliding plate 33 and a metal fitting 34 bent into an abbreviated shape are fixed at symmetrical positions on the circumferential surface. The sliding plate 3
J shown in FIG.
, a pair of left and right sliding protrusions 35A, 35B are protruded from each other, and these protrusions 35A, 35B are formed in the guide plate 25, forming a vertically long sliding groove 36A;
368K each is fitted in such a way that it can slide freely. On the other hand, a cam 38 as a height control mechanism that moves the electromagnetic plunger 26 up and down to change the height position during driving is disposed on the metal fitting 34, and a part of the circumferential surface of this cam 38 is It is constantly in contact with the horizontal piece 34A of the metal fitting 34 from below. The cam 38 is constituted by an eccentric cam fixed to a rotating shaft 39, and rotates integrally with the rotating shaft 39 by a motor (not shown), thereby causing the metal fitting 34, in other words, the electromagnetic plunger 2
6 is moved up and down.

The action mechanism 13 is disposed on the rear end 4b of the six keys 4, and includes a support 41 that is rotated upwardly by the key 4. One end of this support 41 is rotatably supported on a support rail 42 via a support flange 43, and a support heel 4ta provided on the lower surface of the free end side is attached to a carrier implanted on the upper surface of the rear end of the key 4. The capstan screw 44 is always mounted on the capstan screw 44, and is configured such that the upper row can be rotated counterclockwise by raising the capstan screw 44 as the key 4 is driven.
),, on the upper surface of the middle part of this support 41 (-1
A leveling lever 46 that holds a hammer 45 (described later) at an initial position is swingably disposed via a repetition lever 7 range 41.1. This repetition lever 46 is always given a counterclockwise rotational habit by a spring 48, and a repetition button 49 is provided at one end of the repetition lever 46 to abut against the upper surface of the support 41 to restrict rotation of the lever 460. It is attached.

The hammer 45 has a hammer shank 52, one end of which is rotatably supported on a shank rail 51 via a 7-way kink 50, and a hammer wand 53 attached to the other end of the hammer/kink 52. A hammer felt 54 is fixed thereto, and a hammer roller 55 as a buffer member 7 is attached to the lower surface of the rotation fulcrum side of the yank 52, and is normally placed on the upper surface of the other end of the lever 46. I'm ha. .

A jack 61 formed in an abbreviated shape is provided at the free end of the front C scissor boat 410, with its bent portion rotatably supported, and the upper end of this jack 61 is connected to the repetition lever. 46 is always engaged in a long hole 62 provided at the other end thereof while being allowed to rotate by a small angle, and its top end surface is normally in contact with the lower surface of the hammer roller 55 3. Therefore, When the support 41 rotates upward in conjunction with the drive of the key 4, the jack 61 rises together with it and pushes up the hammer row 255, which causes the hammer shank 52 to rotate upward and the hammer felt 54 to move the corresponding string. It is configured to strike three times. Note that the jack 61 has a small jack 6 on its way up.
1A is shank rail 51 and regulating rail 65
When it comes into contact with the regulating button 66 attached through the hammer roller 55 and is prevented from upward movement, it is rotated clockwise and temporarily escaped from the lower part of the hammer roller 55. The jack 61 is connected to the support 41 after the string-striking operation.
It is configured such that when it is released from the regulating button 66 as it descends to zero rotation and returns to rotation due to the force of the spring 48, its upper end enters the lower part of the nozzle roller 55 again.

On the other hand, the hammer 45 remains at 1'1 even after the escape of the jack 61.
After hitting the string 3, it is rotated and lowered by the repulsive force of the string 3 and the hammer, and the roller 55 is held at the initial position 1tt by contacting the repetition lever 46Kfi. , this place.

In this case, the string striking timing and string striking strength of the hammer 45 are naturally determined by the string striking speed of the hammer 451, in other words, the thrusting blade of the jack 61 and the quality of the hammer 45.・ In addition, 70 in FIG. 1 is a bracket to which the support rail 42 and the shank rail 51 are fixed to the keyboard 2 via the action stand γ1, γ3, 7.
A jack button and jack stop for setting the initial position of the four-key jack 61; 75; and 76, a damper lever and a damper constituting a well-known damper mechanism; 77.
78 is the frame and bottle plate on which the string 3 is stretched; 79
is a bank check.

In such a configuration, when an electric signal is supplied to the solenoid coil 28 of the electromagnetic plunger 26 to energize it during automatic performance, the movable iron core 30 is attracted and raised by the action of magnetic flux, so that the lower surface of the rear end of the key 4 is not touched. The up button 31 pushes up. As a result, the key 4 is actuated as if it were pressed by hand, and in conjunction with this, the action mechanism 13 is actuated to strike the string 3 with the hammer 45.

By the way, since the height of the electromagnetic plunger 26 is controlled by the rotation of the cam 38, it is possible to freely change the distance between the string 3 and the hammer felt 54, that is, the flying distance of the hammer 45. So, if L is shortened, it becomes possible to play weak sounds. That is, the electromagnetic plunger 2
When the volume data for driving 6 is below the level,
Because the force of pushing up key 4 is weak, No. 45 is on string 3.
If the striking force is extremely weak even after reaching or reaching the target, it becomes difficult to faithfully reproduce weak sounds. Therefore, if the volume data is below the level where the volume data is, if the cam 39 is rotated by a predetermined angle in accordance with the volume data and the electromagnetic plunger 29 is pushed up, @4 will rise and the flight distance of the hammer 45 will be increased.
, is set to a small value 17, and in this state, when the electromagnetic plunger 26 is driven and the key 4 is pushed up, the hammer 45 reaches the string 3 position in 11 steps and hits the string 3 (7, weak tone a(, Produces a good Pj with a series of weak sounds.

In this case, the -F upward movement amount and timing of the electromagnetic plunger 26 are such that the key sensor 20 activates the -F movement during recording performance.
It can be detected by climbing up. As shown in FIG. 3, this detection signal is once recorded in the memory 90 as keystroke information, and when it is reproduced by the reproduction circuit 91 during playback performance, it is supplied to the electromagnetic plunger 26, No. 16 is the rotating shaft 3 of the -II cam 38.
It is supplied to a servo motor 92 that rotates the motor 9.

In addition, in special playing techniques such as staccato, '11℃
When the magnetic plunger 26 is set lower than the normal high position, the push-up button 31 separates from the key 4, and the driving energy of the tV W+ plunger 26 against the key 4 decreases, so that the movement of the key 4 is controlled by the player's finger. approximates the behavior of , allowing for more faithful staccato.

In the above embodiment, the electromagnetic plungers corresponding to each key are arranged so as to be movable downward, and the electromagnetic plungers are individually controlled. However, the present invention is not limited to this. The configuration 17 may be such that the control is performed in common or for each range.2Also, although the above embodiment has been described with reference to the case where it is applied to a grand type action mechanism, the present invention is not limited to this, and is applicable to an amplifier light type action mechanism. Of course, the present invention can also be applied to an action mechanism.

As explained above, the key drive device for a player piano according to the present invention is configured to move the electromagnetic plunger up and down in accordance with keystroke information and change the distance between the hammer and the string, so that it can be used for soft notes and rapid staccato hits. It is possible to faithfully reproduce special playing techniques such as In addition, the structure is simple and can be easily installed on existing pianos, which has great effects.

[Brief explanation of drawings]

Fig. 1 is a side sectional view showing an embodiment of the action mechanism of a grand automatic performance piano equipped with a key drive device according to the present invention; Fig. 2 is a plan view showing the structure of the electromagnetic plunger installation; Figure 3 is a block diagram showing the control circuit for the electromagnetic plunger.1゜4...Key, 13...
・Action mechanism, 26. . . . 141 magnetic plunger, 38. . . cam. Patent applicant: Nippon Musical Instruments Manufacturing Co., Ltd. Agent: Masaki Yamakawa (and one other person)

Claims (1)

[Claims] An electromagnetic plunger for driving a key is disposed so as to be movable in a direction toward and away from the key, and the movement of the T4f magnetic plunger is controlled in accordance with an electric signal applied to the plunger during playback. A key drive device for a self-playing piano that is characterized by the following: