JPH1055171A - Key driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make possible effectively using magnetic force. SOLUTION: Plural keys 14 are provided turnably on an upper surface side of a key board chassis 12. A key rear end member 31 is provided on the upper surface rear end part of the key 14, and a permanent magnet 32 is provided on the rear end surface of the key rear end member 31. An electromagnet 33 is provided backward the permanent magnet 32 so as to oppose to it. Then, when a current is supplied to the electromagnet 33, the electromagnet 33 gives one magnetic pole of the permanent magnet 32 repulsion for turning the key 14 in the key depressive direction, and gives other magnetic poles attracting force for similarly turning the key 14 in the key depressive direction. Thus, the magnetic force is used effectively compared with the case when the key 14 is turned in the key depressive direction only by the repulsion or the attracting force between the electromagnet 33 and the permanent magnet 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a key driving device for automatically playing a keyboard instrument.

[0002]

2. Description of the Related Art Some keyboard musical instruments such as electronic pianos and acoustic pianos have a key drive for automatic performance. FIG. 11 shows an example of such a key driving device. In this key driving device, a plurality of keys 4 are attached to a shaft 3 provided at a lower end portion of a key support member 2 vertically suspended at a predetermined position in a musical instrument main body case 1 so as to be rotatable in a vertical direction. . A coil 5 wound so as to generate magnetic lines of force in the vertical direction is attached to the lower surface of the rear end of each key 4. Below the coil 5, a belt-shaped permanent magnet 6 is disposed so as to face the coil 5 at a predetermined interval.
When a current is supplied to the coil 5, the coil 5 repels the permanent magnet 6 and pushes the rear end of the key 4 upward. Thus, the key 4 is turned around the shaft 3 and pressed.

[0003]

However, in such a conventional key driving device, the key 4 is turned in the key pressing direction by a repulsive force between one magnetic pole of the coil 5 and one magnetic pole of the permanent magnet 6. Therefore, both the coil 5 and the permanent magnet 6 use only one magnetic pole, and the magnetic force of the other magnetic pole is wasted, and the magnetic force is not effectively used. An object of the present invention is to make it possible to effectively use magnetic force.

[0004]

According to the first aspect of the present invention,
A key that is rotatably provided and has a key rear end portion behind a rotation fulcrum; a constant magnetic field generating means that is provided at the key rear end portion and always generates a magnetic field; The magnetic field is generated only when a current is supplied, and a repulsive force for rotating the key in a key pressing direction is applied to one magnetic pole of the constant magnetic field generating means, and to another magnetic pole. On the other hand, a temporary magnetic field generating means for applying an attraction force for rotating the key in the key pressing direction is provided. According to a second aspect of the present invention, a key is provided rotatably and has a key rear end behind a rotation fulcrum, and a key is provided at the key rear end and generates a magnetic field only when an electric current is supplied. A temporary magnetic field generating means, provided near the temporary magnetic field generating means, always generating a magnetic field, and when a current is supplied to the temporary magnetic field generating means, the key is applied to one magnetic pole of the temporary magnetic field generating means. And a constant magnetic field generating means for applying a repulsive force for rotating the key in the key pressing direction and applying an attractive force for rotating the key in the same key pressing direction to other magnetic poles. It is.

According to the first aspect of the present invention, the temporary magnetic field generating means constantly applies a repulsive force to the one magnetic pole of the magnetic field generating means for rotating the key in the key pressing direction, and the other magnetic pole. To the key in the key-pressing direction, so that the key is rotated in the key-pressing direction by the repulsive force between the temporary magnetic field generating means and the permanent magnetic field generating means, as in the past. The magnetic force can be used more effectively as compared with the case where it is performed. According to the invention described in claim 2, the constant magnetic field generating means applies a repulsive force for rotating the key in the key pressing direction to one magnetic pole of the temporary magnetic field generating means, and applies the repulsive force to the other magnetic pole. Since a suction force for turning the key in the key-pressing direction is also given, the key is turned in the key-pressing direction by the repulsive force between the temporary magnetic field generating means and the constant magnetic field generating means as in the related art. By comparison, the magnetic force can be used effectively.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A keyboard instrument to which a first embodiment of the present invention is applied will be described below with reference to FIGS. FIG. 1 is a sectional view showing the keyboard instrument, FIG. 2 is a plan view of the keyboard instrument, FIG. 3 (A) is a partially enlarged view of FIG. 1, and FIG. 3 (B) is FIG. FIG. 4 is a cross-sectional view taken along line BB of FIG. 4A, FIG. 4 is a cross-sectional view showing a depressed state of the keyboard instrument, and FIG. 5 is a partially enlarged view of FIG. In this keyboard instrument, as shown in FIG. 1, a sheet metal keyboard chassis 1 is placed on a synthetic resin or metal instrument body case 11.
2 is attached via a support member 13 made of sheet metal. On the upper surface side of the keyboard chassis 12, a plurality of keys 14 made of synthetic resin (white keys and black keys, but only the white keys will be described) are arranged in parallel. A substantially U-shaped engaging portion 15 is provided at a vertical portion of the rear end of the key 14, and a spring pressing projection 16 is provided at a predetermined location at the rear end of the lower surface.
Then, the key 14 is inserted into a locking hole 17 formed in the vertical portion of the rear end of the keyboard chassis 12 with the locking portion 15, and the spring pressing projection 16 is disposed on the keyboard chassis 12 below the locking portion 17. By abutting on the spring 18, the return spring 18 can be turned up and down around the locking portion 15 by elastic deformation.

At the center of the lower surface of the key 14, first and second switch pressing projections 19 and 20 having a cross-shaped cross section are integrally provided. Push button type first and second rubber switches 21 and 22 are arranged below the first and second switch pressing projections 19 and 20, respectively. These rubber switches 21 and 22 are provided on a circuit board 23 attached to the lower surface of the keyboard chassis 12, and are disposed in a not-shown fool hole formed in the keyboard chassis 12.

The key 14 is urged upward by the spring force of the return spring 18 and the elastic force of the rubber switches 21 and 22. Usually, the key 14 is generally suspended from the lower end of the front end of the both side plates 14a of the key 14. The L-shaped stopper piece 24 is used for the keyboard chassis 12.
Is positioned at a predetermined initial position (upper limit position) by contacting a belt-shaped upper limit stopper 26 made of felt or the like provided on the lower surface of the keyboard chassis 12 through a stupid hole 25 formed in the keyboard chassis 12. At a predetermined position at the front end of the keyboard chassis 12, a substantially L-shaped key guide 27 is provided for preventing the key 14 from laterally swaying and for guiding the key 14 up and down. A belt-shaped lower limit stopper 28 made of felt or the like for restricting the lower limit position of the key 14 is provided at another predetermined position of the front end of the keyboard chassis 12 by abutting the lower end of the stopper piece 24. .

At the rear end of the upper surface of each key 14, a key rear end member 31 is provided.
Is screwed. On the rear end face of the key rear end member 31, a permanent magnet (always magnetic field generating means) 32 is provided. In this case, as shown in FIG. 3A, the permanent magnet 32 is magnetized such that the upper portion 32a has an S pole and the lower portion 32b has an N pole. The outer peripheral surface of the permanent magnet 32 is formed in a curved shape having a curvature corresponding to the rotation of the key 14. Musical instrument body case 11
At a position facing the upper permanent magnet 32, an electromagnet (temporary magnetic field generating means) 33 is attached via a support member 34 made of sheet metal. The electromagnet 33 is shown in FIGS.
As shown in FIG. 5, a coil 36 is wound around a central end 35b of an E-shaped iron core 35 having three ends 35a to 35c. In this case, each end 35a of the iron core 35
35c are formed along the outer peripheral surface of the permanent magnet 32 so that the distance between the permanent magnet 32 and each of the ends 35a to 35c does not change when the key 14 rotates.

Next, the operation of the keyboard instrument configured as described above will be described. As shown in FIG. 5, when a current is supplied to the coil 36 of the electromagnet 33, the upper end 35 of the iron core 35 is supplied.
An N pole is generated at a, an S pole is generated at the center end 35b, and an N pole is generated at the lower end 35c. In this case, the upper end 35 of the iron core 35
a and the upper part 32a of the permanent magnet 32, and the iron core 35
Attraction force acts between the central end 35b of the permanent magnet 32 and the lower part 32b of the permanent magnet 32 to push the permanent magnet 32 upward, and the lower end 53c of the iron core 35 and the lower part 3
A repulsive force acts on the permanent magnet 32 upwardly. Thereby, as shown in FIG. 4, the corresponding key 14 is driven by the spring force of the return spring 18 and the rubber switch 2.
The key is depressed against the elastic force of 1, 22. Then, the first and second switch pressing projections 19 and 20 press the first and second rubber switches 21 and 22, respectively, whereby the first and second rubber switches 21 and 22 are sequentially switched on with a time lag. Becomes When the second rubber switch 22 is turned on, key-on data for instructing the tone generator (not shown) to start generating a musical tone is obtained. Is obtained as initial touch data for initial control of. Next, when the supply of current to the coil 36 of the electromagnet 33 is stopped, the magnetic field of the electromagnet 33 disappears, whereby the key 14
8 and the elastic force of the rubber switches 21 and 22 return to the original initial position.

In such a keyboard instrument, the electromagnet 33 applies a repulsive force to one magnetic pole of the permanent magnet 32 to rotate the key 14 in the key-pressing direction, and applies the key 14 to the other magnetic pole. Is also given an attractive force for rotating the key 4 in the key-pressing direction, so that the key 4 is rotated in the key-pressing direction only by the repulsive force between the coil 5 and the permanent magnet 6 as shown in FIG. Compared to the case, the magnetic force can be used effectively. In addition, since the distance between the permanent magnet 32 and the electromagnet 33 can be reduced, the larger the distance between the two, the smaller the leakage flux that increases, and the lower the power consumption.

In the first embodiment, the key rear end member 31 is provided separately from the key 14. However, the present invention is not limited to this.
May be provided integrally.

Next, a keyboard instrument to which the second embodiment of the present invention is applied will be described with reference to FIGS. FIG. 6 is a sectional view showing the keyboard instrument, FIG. 7A is a partially enlarged view of FIG. 6, and FIG.
FIG. 8 is a cross-sectional view taken along the line B, FIG. 8 is a cross-sectional view showing a depressed state of the keyboard instrument, and FIG. 9 is a partially enlarged view of FIG. As shown in FIG. 6, the keyboard instrument has a musical instrument main body case 41 made of synthetic resin or metal. An opening 42 is formed on the front side (left side) of the musical instrument main body case 41, and the rear side (right side) rises with a steep inclination and is formed one step higher. A key support member 43 is vertically provided at a predetermined position in a portion of the musical instrument body case 41 which is formed one step higher. A shaft 44 is provided at the lower end of the key support member 43.
Is provided. A plurality of keys made of synthetic resin (white keys and black keys, but only white keys will be described) on the shaft 44.
45 is attached so that rotation is possible in the up-down direction. At the rear end of each key 45, a coil (temporary magnetic field generating means) 46 wound so as to generate magnetic lines of force in the left-right direction is attached. The key 45 has a band-shaped buffer member 47 made of felt or the like provided on the lower surface of the front part of the musical instrument main body case 41, usually with an L-shaped stopper part 45 a formed at the front end thereof.
Is positioned at a predetermined initial position (upper limit position). The front end of the key 45 projects outside through the opening 42.

A circuit board 48 is provided above the key 45 in the instrument main body case 41. This circuit board 48 is connected to the coil 46 via a lead wire 49. Behind the coil 46, a permanent magnet 50 is provided.
A substantially L-shaped upper yoke 51 is provided above the permanent magnet 50 and above the permanent magnet 50, and substantially L-shaped below the coil 46 and below the permanent magnet 50 so as to face the upper yoke 51. The lower yoke 52 is provided. In this case, the permanent magnet 50 and the yokes 51 and 52 are arranged in a substantially U-shape as a whole, and are arranged at a ratio of one to a plurality of keys 45 (see FIG. 7B). FIG.
As shown in (A), the upper part 50a of the permanent magnet 50 has S
The upper yoke 51 has an N pole at the base end 51 a and a tip 51
b is an S pole, and the lower yoke 52 is a base end 52a.
Is an S pole and the tip 52b is an N pole. Incidentally, the permanent magnetic field generating means has a permanent magnet 50 and both yokes 51 and 52 arranged in a U-shape.

Next, the operation of the keyboard instrument configured as described above will be described. As shown in FIG. 9, when a current is supplied to the coil 46, an N pole is generated at the right end of the coil 46 and an S pole is generated at the left end. In this case, the upper yoke 51
Attraction force acts between the tip end 51b of the lower yoke 52 and the right end of the coil 46 to push the coil 46 upward, and a repulsive force acts between the tip end 52b of the lower yoke 52 and the right end of the coil 46. Then, the coil 46 is pushed upward. As a result, as shown in FIG. 8, the key 45 is rotated about the shaft 44 and pressed, and an automatic performance is performed. Next, when the supply of current to the coil 46 is stopped, the magnetic field of the coil 46 disappears, whereby the key 45 is returned to the initial position.

In such a keyboard instrument, the permanent magnet 50 applies a repulsive force for rotating the key 45 in the key pressing direction to one magnetic pole of the coil 46 via the two yokes 51 and 52, and Since an attractive force for rotating the key 45 in the key pressing direction is applied to the other magnetic poles as well, the key 4 is only generated by the repulsive force between the coil 5 and the permanent magnet 6 as shown in FIG. The magnetic force can be effectively used as compared with the case where is rotated in the key pressing direction.

In the second embodiment, a coil 46 wound so as to generate magnetic lines of force in the left-right direction is provided at the rear end of the key 45, and an S pole is provided on an upper portion 50a behind the coil 46.
A permanent magnet 50 having an N-pole magnetized is provided at a lower portion 50b, an upper yoke 51 is provided at an upper portion of the permanent magnet 50, and a permanent magnet 5 is provided.
0, the lower yoke 52 is provided, but the invention is not limited thereto.
For example, it may be configured as shown in FIG. In a modification of the keyboard instrument of the second embodiment shown in FIG. 10, a coil 61 wound so as to generate magnetic lines of force in the vertical direction is provided at the rear end of the key 45, and an N pole is provided on the left behind the coil 61. S on the right
A permanent magnet 62 with magnetized poles is provided, an upper yoke 63 is provided on the upper left side of the permanent magnet 62, and a lower yoke 64 is provided on the lower left side of the permanent magnet. In the second embodiment, the permanent magnet 50 and the yokes 51 and 52 are arranged in a U-shape as the constant magnetic field generating means. However, the present invention is not limited to this. It may be formed.

[0018]

As described above, according to the first aspect of the present invention, the repulsive force for the temporary magnetic field generating means to constantly rotate the key with respect to one magnetic pole of the magnetic field generating means in the key pressing direction. And attraction to the other magnetic poles to rotate the key in the same key-pressing direction, so that the repulsive force between the temporary magnetic field generating means and the permanent magnetic field generating means as in the related art. Compared to the case where the key is rotated in the key pressing direction, the magnetic force can be used more effectively. According to the invention described in claim 2, the constant magnetic field generating means applies a repulsive force for rotating the key in the key pressing direction to one magnetic pole of the temporary magnetic field generating means, and applies the repulsive force to the other magnetic pole. Since a suction force for turning the key in the key-pressing direction is also given, the key is turned in the key-pressing direction by the repulsive force between the temporary magnetic field generating means and the constant magnetic field generating means as in the related art. By comparison, the magnetic force can be used effectively.

[Brief description of the drawings]

FIG. 1 is a sectional view of a keyboard instrument to which a first embodiment of the present invention is applied.

FIG. 2 is a plan view of the keyboard instrument.

3A is a partially enlarged view of FIG. 1, and FIG.
Sectional drawing which follows the B line.

FIG. 4 is a cross-sectional view showing a depressed state of the keyboard instrument.

FIG. 5 is a partially enlarged view of FIG. 4;

FIG. 6 is a sectional view of a keyboard instrument to which a second embodiment of the present invention is applied.

7A is a partially enlarged view of FIG. 6, and FIG.
Sectional drawing which follows the B line.

FIG. 8 is a cross-sectional view showing a depressed state of the keyboard instrument.

FIG. 9 is a partially enlarged view of FIG. 8;

FIG. 10 is an enlarged view showing a modification of the keyboard instrument of the second embodiment.

FIG. 11 is a sectional view showing a conventional key driving device.

[Explanation of symbols]

 12 keyboard chassis 14 key 31 key rear end member 32 permanent magnet 33 electromagnet

Claims (2)

[Claims] 1. A key rotatably provided and having a key rear end behind a rotation fulcrum, a constant magnetic field generating means provided at the key rear end and always generating a magnetic field, It is provided near the magnetic field generating means, generates a magnetic field only when a current is supplied, and applies a repulsive force for rotating the key in a key pressing direction to one magnetic pole of the magnetic field generating means. And a temporary magnetic field generating means for applying an attractive force to the other magnetic pole to rotate the key in the same key pressing direction. 2. A key that is rotatably provided and has a key rear end behind a rotation fulcrum; and a temporary magnetic field generation that is provided at the key rear end and generates a magnetic field only when an electric current is supplied. Means, which is provided near the temporary magnetic field generating means, always generates a magnetic field, and presses the key against one magnetic pole of the temporary magnetic field generating means when current is supplied to the temporary magnetic field generating means. And a constant magnetic field generating means for applying a repulsive force for rotating the key in the direction and also applying an attractive force for rotating the key in the same key-pressing direction to other magnetic poles. Key drive device.