JPH0310550Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to actuators for player pianos, and is particularly easy to install, eliminates the difference in driving force between the actuators arranged in two rows, and improves playback performance. This is how it was done.

[Conventional technology]

In general, a well-known electromagnetic plunger is used as an actuator to drive the keys of a player piano, which consists of an excitation coil, a movable iron core loosely inserted through the center hole of a bobbin, and a yoke that houses the excitation coil and forms a magnetic path. By driving this with an electric signal obtained by reproducing an electric signal previously recorded on a recording medium such as a tape, the key is operated as if it were pressed by hand. FIG. 3 shows a conventional example of this type of actuator, in which a mounting plate 3 extending long in the direction of arrangement of keys 2 (direction of arrow A) is arranged almost vertically at a predetermined location on the lower surface of a shelf board 1. has been done. A plurality of electromagnetic plungers 5 are arranged on the mounting plate 3 in two stages, upper and lower, corresponding to each key 2, and are movable and adjustable in the direction in which the keys 2 are arranged. On the back of the is a T-shaped long 4 in the left and right direction.
Two sliding grooves 4 are formed parallel to each other at predetermined intervals in the vertical direction. On the other hand, each electromagnetic plunger 5 includes a yoke 6 formed in a substantially square shape from a metal plate such as soft iron, and this yoke 6 is connected to a set screw 7.
It is positioned and fixed by a square nut 8 and a square nut 8. An excitation coil 10 and a movable iron core 11 are arranged in the inner space of the yoke 6. The movable iron core 11 protrudes above and below the yoke 6, and its upper protruding end further passes through the elongated hole 12 of the shelf board 1, and has a protruding button 13 at its top that closely opposes or lightly contacts the lower surface of the rear end of the key 2. are integrally provided. In addition,
The upper electromagnetic plunger group and the lower electromagnetic plunger group are arranged in a staggered manner so as not to interfere with each other, so that they are shifted in the left-right direction by the distance between the keys 2.

[Problem that the invention attempts to solve]

However, in such a conventional actuator, the attachment of the electromagnetic plunger 5 to the attachment plate 3 is extremely troublesome and time consuming, resulting in poor assembly workability. In particular, when adjusting the mounting position of the electromagnetic plunger 5, the square nut 8 inserted into the sliding groove 4 has poor slippage, and the corner may not stick to the groove 4, making fine adjustment difficult and time-consuming. If you try to move the square nut 8 with excessive force, it will move more than necessary and the movable core 11 will come into contact with another electromagnetic plunger located diagonally below or above, causing the inconvenience of bending the movable core 11. It was hot. Furthermore, since the electromagnetic plungers 5 are arranged in two stages, upper and lower, the height of the mounting plate 3 is increased and hangs below the shelf board 1, which significantly deteriorates the external appearance of the piano.

Therefore, as a means to solve this problem, various actuators for player pianos have been proposed in which a plurality of electromagnetic plungers are arranged in one yoke structure to form a unit, thereby improving assembly workability. (Example: Utility Model Application Publication No. 59-20296). However, in such an actuator, adjacent electromagnetic plungers are arranged in a staggered manner in a plan view so that they do not interfere with each other, and are alternately shifted in the front and rear directions, so that the driving of the front and rear electromagnetic plunger groups is difficult. There was a problem in that there was a difference in power, and the performance could not be faithfully reproduced.

That is, when the electromagnetic plungers 5 are installed in two rows, front and back, the distance between the push-up button of the electromagnetic plunger group in the front row and the bottom surface of the key is equal to that of the push-up button of the electromagnetic plunger group in the back row, depending on the inclination angle of the key 2 in the initial position state. Since the distance between the key and the lower surface of the key is larger (approximately 1.2 mm), a time lag occurs in driving the key 2, and the driving force of the electromagnetic plunger in the rear row becomes larger than that of the electromagnetic plunger in the front row.

[Means for Solving the Problems] The actuator for the player piano according to this invention was made to solve the above-mentioned problems, and includes a support member extending in the direction in which the keys of the player piano are arranged, and the keys. and a plurality of electromagnetic plungers arranged in a staggered manner, the electromagnetic plungers being fixed to the support member facing each other and adjacent to each other being displaced in the longitudinal direction of the key, and arranged at the upper end of the movable member of the electromagnetic plungers. In an actuator for a player piano, which applies a driving force to each key by abutting a push-up button provided on the lower surface of the rear end of each key, the side electromagnetic member arranged on the side near the rotation center of the key; The upward stroke of the push-up button of the plunger is set to be smaller than the upward stroke of the push-up button of the rear electromagnetic plunger arranged far from the rotation center of the key, and the upward stroke of the push-up button of the front electromagnetic plunger is The initial position is set higher than the initial position of the push-up button of the rear electromagnetic plunger by approximately the same distance as the difference in the upward stroke.

[Effect]

In this invention, the initial position height of the push-up button of the electromagnetic plunger on the front row side and the back row side is changed to equalize the distance from the bottom surface of the key, and the upward stroke of the push-up button of the electromagnetic plunger on the front row side is compared with that on the back row side. Since this is set small, the driving forces of the electromagnetic plungers in the front row and the rear row can be made almost equal. Furthermore, since the unit is made up of a pair of front and rear mounting plates, a connecting plate, and a plurality of electromagnetic plungers, the structure is simple, the number of parts is small, and assembly and disassembly operations are easy.

〔Example〕

This invention will be described in detail below based on embodiments shown in the drawings.

FIG. 1 is a side view of a keyboard section incorporating an actuator according to this invention, and FIG. 2 is a plan view of a main part of the actuator. In addition, the same components as in FIG. 3 are indicated by the same reference numerals.
The explanation will be omitted. In these figures, a long hole 20 that is long in the left-right direction is formed in the rear end of the shelf 1 in correspondence with the rear end 2a of the key 2, and a key drive unit 21 is disposed in this long hole 20. has been done.

The key drive unit 21 includes a pair of front and rear mounting plates 23, 24 that are long in the longitudinal direction of the elongated hole 20, and a connecting plate 25 formed in a substantially U-shape that connects the lower ends of the pair of mounting plates 23, 24. Each mounting plate 23,
The electromagnetic plunger 5 includes a plurality of electromagnetic plungers 5 each disposed on the inner surface of the electromagnetic plunger 24, that is, on the opposing surface, with a substantially U-shaped yoke 6 interposed therebetween. When assembling the key drive unit 21, each mounting plate 23,
The electromagnetic plungers 5 are arranged in advance on each of the mounting plates 24, and then both the mounting plates 23 and 24 are integrally connected by a connecting plate 25. As shown in FIG. 2, the electromagnetic plungers 5 are arranged in a staggered manner so that they are alternately shifted back and forth in a plan view, so that, for example, odd-numbered electromagnetic plungers 5A are arranged on the inner surface of the mounting plate 23 on the front side. Even-numbered electromagnetic plungers 5B are arranged on the inner surface of the mounting plate 24 on the rear side in correspondence with the even-numbered keys 2B.

In this case, the electromagnetic plungers 5 on the front row side and the rear row side
Although the installation heights of A and 5B are almost the same, in the initial state all the push-up buttons 1 of the plungers 5
The height of the push-up button 13A of the electromagnetic plunger 5A on the front row side is set higher than that of the push-up button 13B of the electromagnetic plunger 5B on the back row side so that the distance between the button 3 and the lower surface of the key is equal. Further, the upward stroke L ₁ of the push-up button 13A of the electromagnetic plunger 5A on the front row side is the upward stroke L ₂ of the push-up button 13B of the electromagnetic plunger 5B on the rear row side.
As a result, the uppermost positions of the front and rear push-up buttons 13 are aligned as shown by the dashed line in FIG. It is set. The difference in height between the front row of push-up buttons 13A and the rear row of push-up buttons 13B is equal to the difference in the upward strokes L ₂ -L ₁ .

In the figure, 30 is the middle of the reed, 31 is the back of the reed, 32 is felt, 33 is a balance key pin, and 34 is a capstan. Further, when the key 2 is pressed, it is rotated to a substantially horizontal state.

According to the actuator having such a structure, the structure of the key drive unit 21 is extremely simple, the number of parts is small, and assembly and disassembly operations are easy. Furthermore, since the key drive unit 21 is disposed within the elongated hole 20 of the shelf board 1,
There is almost no protrusion below the shelf board, and the appearance is good.

Furthermore, since the distance between the front row push-up button 13A and the rear row push-up button 13B from the key bottom surface is set equal, the driving forces of the front row electromagnetic plunger 5A and the rear row electromagnetic plunger 5B can be set approximately equal. Can be done. Therefore, the performance can be reproduced faithfully, and even weak keying force (driving force) can be obtained in the front and rear rows, especially when playing soft sounds, so that the soft sound reproduction range is expanded to the soft sound side, resulting in good playback performance. It will be done. Also, by changing the upward stroke L ₁ and L ₂ ,
Since the heights of the push-up buttons 13A and 13B in the front and rear rows are made the same when they are raised to the maximum, the amount of struggle of all the keys 2 can be made equal.

[Effect of idea]

As described above, according to the actuator for the player piano according to this invention, the initial position heights of the push-up buttons of the electromagnetic plungers in the front row and the back row are different, and the distance from the bottom surface of the key is set to be equal. The driving forces of the electromagnetic plungers in the front row and the rear row can be set to be approximately equal, and the rise characteristics of the keys and the reproducibility of the performance can be improved. Furthermore, the structure of the key drive unit is simple, the number of parts is small, and assembly work, assembly work to the piano, and disassembly work are easy.

[Brief explanation of drawings]

FIG. 1 is a side cross-sectional view of a keyboard section incorporating an actuator according to this invention, FIG. 2 is a plan view of essential parts of the actuator, and FIG. 3 is a perspective view showing a conventional example of the actuator. 1... Shelf board, 2... Key, 5, 5A, 5B... Electromagnetic plunger, 6... Yoke, 10... Excitation coil, 11... Moving iron core, 13, 13A, 13B...
...Push-up button, 20...Long hole, 21...Key drive unit, 23, 24...Mounting plate, 25...
...Connection plate.

Claims (1)

[Claims for Utility Model Registration] A support member extending in the direction in which the keys of a player piano are arranged; and a support member fixed to the support member facing the keys,
It is equipped with a plurality of electromagnetic plungers arranged in a staggered manner such that adjacent ones thereof are displaced in the longitudinal direction of the key, and a push-up button disposed at the upper end of the movable member of the electromagnetic plunger is used to move the push-up button of each of the keys. In the actuator of the player piano that comes into contact with the lower surface of the rear end and applies a driving force to each of the keys, the upward stroke of the push-up button of the electromagnetic plunger on the front row side arranged near the rotation center of the key is defined as above. The upward stroke of the push-up button of the rear electromagnetic plunger arranged far from the rotation center of the key is set to be smaller than the initial position of the push-up button of the front electromagnetic plunger. An actuator for a player piano, characterized in that the actuator is set higher than the initial position of the up button by approximately the same distance as the difference in the up stroke.