JP5023536B2 - Key drive device and keyboard instrument - Google Patents

Description

  The present invention relates to a key drive device and a keyboard instrument.

Some keyboard instruments such as conventional electronic keyboards and acoustic pianos are provided with a key driving device that individually drives each key (see, for example, Patent Documents 1 and 2). In this kind of keyboard instrument, each key can be driven by a key driving device in accordance with performance information corresponding to a series of musical sounds constituting a musical composition.
In a conventional key drive device, a solenoid using a solenoid as in Patent Document 1 or a combination of a stepping motor and a gear mechanism as in Patent Document 2 is used as an actuator. Accordingly, each key is driven by supplying a drive voltage or a drive signal to a solenoid, a stepping motor or the like according to the performance information.
JP 59-37594 A JP 2004-294769 A

However, since the above-described conventional key driving device uses a combination of a solenoid, a stepping motor, and a gear mechanism as an actuator, there arises a problem that the key driving device itself is increased in size and weight. This defect has a problem that it cannot be applied to an electronic keyboard in which portability is particularly important.
In addition, since the above-described actuator is used in the conventional key driving device, there is a problem that a large amount of power is required to obtain a sufficient driving force at the initial stage of key driving when the key starts to be driven. This problem has a problem that it becomes difficult to apply to a battery-specific electronic keyboard.

  In view of the circumstances described above, an object of the present invention is to provide a key driving device that can be reduced in size and weight and can drive a key with power saving, and a keyboard instrument including the key driving device.

In order to solve the above problems, the present invention proposes the following means.
The present invention is a key drive device for driving a key supported so as to be swingable with respect to a frame, and biasing means for biasing the key in one of its swing directions, and for swinging the key. A magnetic body that swings in conjunction with the frame, an iron core formed in a substantially U shape, and a coil wound around the iron core, and the current is flowing through the coil. An electromagnet that attracts the magnetic body with a magnetic force so as to swing the key in the other swinging direction, and the magnetic body is swingable in accordance with the other swinging direction of the key. One end of the iron core is disposed at the end of the magnetic body located away from the fulcrum serving as the center of oscillation of the magnetic body and contacts the magnetic body, and the other end of the iron core is connected to the fulcrum and the fulcrum through the gap between the magnetic member in the middle portion of the magnetic body located between the end It proposes a key driving apparatus characterized by being directed disposed.

Further, the present invention is a key driving device for driving a key supported so as to be swingable with respect to a frame, comprising a biasing means for biasing the key in one of the swinging directions. The means is composed of a rod-shaped magnetic body that swings relative to the frame in conjunction with the swing of the key and biases the key in the one swinging direction by its own weight, and is formed in a substantially U-shape. The magnetic material is attracted by a magnetic force so that an electromagnet composed of an iron core and a coil wound around the iron core swings the key in the other swinging direction while a current flows through the coil. The one end of the iron core is located away from the fulcrum that is the center of swinging of the magnetic body, with the magnetic body swingable in accordance with the other swinging direction of the key. in contact with the magnetic body while being arranged at the end of the magnetic body, the other end of the iron core, the fulcrum It proposes a key driving apparatus characterized by being oppositely arranged with a gap between the magnetic member in the middle portion of the magnetic body located between the end portions.

According to the key driving device according to these inventions, the key is disposed at the initial position where the key is biased by the biasing means in a state where no current flows through the coil. When a current is passed through the coil from this state, the magnetic body is attracted to one end portion of the iron core by the magnetic force and swings, and the key moves against the biasing force of the biasing means by the swinging of the magnetic body. Oscillate in the oscillating direction.
Here, when a current is passed through the coil as described above, since the magnetic body is in contact with one end of the iron core, the magnetic body is magnetized by the electromagnet, and the magnetic body facing the other end of the iron core is The magnetic pole is opposite to the magnetic pole at the other end of the iron core. That is, in this state, the magnetic flux density between the other end portion of the iron core and the magnetic body is larger than that in the case where the iron core and the magnetic body are spaced apart. Therefore, even if the current flowing through the coil of the electromagnet is reduced, the magnetic force for attracting the magnetic body can be increased so that the key is swung in the other swinging direction, and the key is driven at the initial position of the key. A sufficient initial driving force can be obtained.

When the biasing means is made of a magnetic body, the key is biased in one swinging direction based on the swinging of the magnetic body due to gravity.

Further, according to the lock driving device according to these inventions, the other end of the iron core is disposed at a position closer to the fulcrum than the end of the magnetic body, so that the gap between the other end of the iron core and the magnetic body is reduced. Even in this case, the swing range of the magnetic body can be increased. Therefore, it is possible to expand the rocking range of the key interlocked with the rocking of the magnetic body.

The present invention also proposes a key driving device characterized in that, in the key driving device, the electromagnet can swing with respect to the frame with a middle part of the iron core as a fulcrum.
According to the key drive device of the present invention, when the magnetic body is attracted to the other end of the iron core by a magnetic force in a state where an electric current is passed through the coil, the electromagnet swings together with the magnetic body, thereby The magnetic body can be swung in a direction approaching the other end portion of the iron core while reliably holding the state in contact with the one end portion of the iron core.

Further, the present invention is the key drive device, wherein the electromagnet is fixed to the frame, and a contact surface that contacts the magnetic body is formed at one end of the iron core, and the contact surface is the other side of the key. The key driving device is characterized in that it extends in the swinging direction of the magnetic body interlocking with the swinging direction of the key.
According to the lock driving device according to the present invention, when the other end portion of the iron core and the magnetic body are attracted by a magnetic force in a state where an electric current is passed through the coil, the contact portion of the magnetic body that contacts the one end portion of the iron core. By moving on the contact surface, the magnetic body can be swung in a direction approaching the other end portion of the iron core while reliably holding the state where the magnetic body is in contact with one end portion of the iron core.

Further, the present invention provides a keyboard instrument that is arranged a plurality of keys which are swingably supported with respect to the frame, with the lock driving device, and the performance information generator for generating the music data for automatic performance, A keyboard instrument is provided, comprising: a key drive control device for passing a current through a coil of the electromagnet corresponding to the key selected based on the music data.

  According to the keyboard instrument of the present invention, each key of the keyboard instrument can be swung in association with the music data. Therefore, since the key to be pressed with the finger can be notified to the player of the keyboard instrument by the movement of each key, the movement of each key according to the music data can be directly felt by the finger.

Furthermore, the present invention proposes a keyboard instrument characterized by comprising sounding means for generating a musical tone so as to synchronize with the driving of the key based on the music data.

According to the present invention, even if the current flowing through the coil of the electromagnet is reduced, the magnetic force attracting the magnetic body to the other end of the iron core can be increased, so that sufficient initial driving force can be obtained even with power saving. it can.
In addition, since the key driving device is configured by only one electromagnet and a magnetic body, as compared with the case where the key driving device is configured with a combination of a solenoid, a stepping motor, and a gear mechanism as in the past, The lock drive device can be easily reduced in size and weight.

Furthermore, according to the present invention, by giving the magnetic body a role as an urging means, it is possible to reduce the number of component parts of the lock driving device and to reduce its manufacturing cost.

In addition, according to the present invention, the rocking range of the magnetic body can be increased, so that the rocking range of the key interlocked with the rocking of the magnetic body can be expanded.

Further, according to the present invention, when the magnetic body is swung in a direction approaching the other end of the iron core, the state in which the magnetic body is in contact with one end of the iron core can be securely held. The magnetic flux density between the other end of the iron core and the magnetic body can be reliably prevented from decreasing.

Further , according to the present invention, the movement of each key according to the music data can be directly felt by the finger that actually presses the key, so that it is possible to efficiently practice the keyboard instrument.

Furthermore, according to the present invention, it is possible to automatically play the keyboard instrument with power saving by generating the musical sound of the music data from the sound generation means in synchronization with the driving of the key based on the music data.

  Hereinafter, a keyboard instrument according to an embodiment of the present invention will be described with reference to FIGS. The keyboard musical instrument of the present embodiment is configured by arranging a plurality of keys supported so as to be swingable with respect to a frame constituting the casing, and individually drives the keys of the keyboard as shown in FIG. A key driving device 1 for performing the performance, a performance information generating device 3 for outputting music data for automatic performance, and a key driving control device 5 for controlling the key driving device 1 so as to drive a key selected based on the music data. I have. Note that the music data is information on music that can be played on a keyboard instrument, for example, in the MIDI format.

  The performance information generating device 3 reads out music data from a storage device (not shown) such as a RAM and a ROM built in the keyboard instrument and various storage media (not shown), and each musical sound of the music data is read by the key drive control device 5. Is output. The music data includes timing information for generating each tone according to the speed of the song (hereinafter referred to as tone generation timing information), note information for each tone of the song (hereinafter referred to as note information). And other information. Further, the timing at which each musical tone of the music data is output from the performance information generating device 3 to the key drive control device 5 is performed based on the sound generation timing information described above.

  As shown in FIG. 2, each key 7 of the keyboard instrument can swing with respect to a frame (not shown) with the rear end 7b side as a fulcrum. One key driving device 1 is provided corresponding to each key 7 of the keyboard musical instrument, and is configured to drive the key 7 by magnetic force. The key drive device 1 is disposed below the key 7 and is attached to a swing lever (magnetic body) 9 and a rear end (end portion) 9b of the swing lever 9 that are swingably attached to the frame. And an electromagnet 11 disposed on the surface.

The swing lever 9 is made of a magnetic material such as iron, and is arranged so that the longitudinal direction thereof is the front-rear direction of the key 7. The swing lever 9 is supported by the frame so that the middle portion thereof can swing as a fulcrum F1. Has been. Since the front end 9 a of the swing lever 9 is engaged with the front end 7 a of the key 7, the swing lever 9 swings around the fulcrum F 1 in conjunction with the swing of the key 7. Since the center of gravity of the swing lever 9 is shifted toward the rear end 9b from the fulcrum F1, the key 7 is biased in one of the swing directions (A direction) by the weight of the swing lever 9. Become. That is, the swing lever 9 constitutes a biasing means 13 that biases the key 7 in the A direction. Further, since the swing lever 9 plays a role as a weight, the key 7 can have a keystroke sensation similar to an acoustic piano.
At the rear end 9b of the swing lever 9, a restricting member 15 that is fixed to the frame and restricts swinging in the A direction is disposed. The swing lever 9 abuts on the restricting member 15 by its own weight. It will be. In this state, the key 7 is placed at the initial position where it is stationary.

The electromagnet 11 is composed of an iron core 17 formed in a substantially U shape and a coil 19 wound around the core 17, and the key 7 is reverse to the A direction in a state where a current flows through the coil 19. The swing lever 9 is arranged at a position for attracting it by a magnetic force so as to swing in the swing direction (direction B). That is, the electromagnet 11 is disposed at a position closer to the rear end 9b of the swing lever 9 than the fulcrum F1 and close to the electromagnet 11 when the swing lever 9 swings in the B direction.
The iron core 17 includes an iron core body 21 extending in the longitudinal direction of the rocking lever 9, and two projecting portions 23 and 25 projecting from both ends of the iron core body 21 toward the rocking lever 9.

The coil 19 described above is wound around the iron core body 21. Here, the coil 19 is electrically connected to a power source 27, and energization from the power source 27 to the coil 19 is switched by a switch 29.
The first projecting portion (one end portion) 23 constituting the iron core 17 is disposed to face the rear end 9b of the swing lever 9, and the second projecting portion (other end portion) 25 is a swing lever. 9 is arranged to face the middle part of the swing lever 9 located between the fulcrum F1 of the 9 and the rear end 9b. Further, the tip surfaces 23 a and 25 a of the projecting portions 23 and 25 facing the swing lever 9 are formed in parallel along the longitudinal direction of the swing lever 9.

The electromagnet 11 configured in this manner is supported so as to be able to swing with respect to the frame with the middle part of the iron core body 21 as a fulcrum F2. The swinging direction of the first protrusion 23 is the swing lever 9. The direction in which the second protrusion 25 moves away from the swing lever 9 (D direction) and the first protrusion 23 moves away from the swing lever 9 and the second protrusion 25 becomes the swing lever 9. The direction is approaching (C direction).
The fulcrum F2 of the electromagnet 11 coincides with the position of the center of gravity of the electromagnet 11, and when the swing lever 9 is in contact with the restricting member 15 and the electromagnet 11 is not subjected to external force, the swing lever 9 and the two positions A gap is formed between each of the front end surfaces 23a and 25a of the protrusions 23 and 25. Further, the gap between the swing lever 9 and the first protrusion 23 in this state is narrower than the gap between the swing lever 9 and the second protrusion 25.

The operation of the lock driving device 1 configured as described above will be described below.
As shown in FIG. 2, in a state where no current flows through the coil 19, the rear end 9 b of the swing lever 9 abuts against the regulating member 15 due to the weight of the swing lever 9, and the key 7 is arranged at the initial position. The From this state, as shown in FIG. 3, when the switch 29 is switched to pass a current through the coil 19, a magnetic flux is generated from the first protrusion 23 toward the rear end 9 b of the swing lever 9, and the electromagnet 11. The rear end 9b of the swing lever 9 is attracted to the first protrusion 23 by the magnetic force of. As a result, the key 7 and the swing lever 9 swing in the B direction against the biasing force of the biasing means 13 until the rear end 9b of the swing lever 9 contacts the first protrusion 23. Become.

  At this time, the magnitude of the current flowing through the coil 19 is such that the magnetic force is generated so that the rear end 9b of the swing lever 9 having a small gap with the first projection 23 can be attracted by the first projection 23. Thus, it is not sized to generate a magnetic force that attracts the middle portion of the swing lever 9 having a large gap with the second protrusion 25 by the second protrusion 25. That is, even when a current is passed through the coil 19 as described above, a magnetic flux is generated from the second protrusion 25 toward the middle portion of the swing lever 9, but the swing lever 9 swings in the B direction based on this magnetic flux. It doesn't move.

Specifically, for example, a coil 19 is formed by winding a copper wire having a diameter of 0.21 mm around a 5.0 mm square core body 21, and a gap of 7 mm is formed between the swing lever 9 and the first protrusion 23. When a voltage of 35 V is applied to the coil 19 and a current of 1.5 A is applied to the coil 19, the magnetic flux density reaching the swing lever 9 from the first protrusion 23 becomes about 1000 G, and the electromagnet 11 An attractive force of about 0.5 to 1.0 N is generated between the swing lever 9 and the first projecting portion 23 by the magnetic force. The magnitude of this attractive force is sufficient to cause the swing lever 9 spaced from the electromagnet 11 to swing.
In addition, since the clearance gap between the rocking lever 9 and the 2nd protrusion part 25 is larger than said 7 mm, the magnetic flux density which reaches | attains the rocking lever 9 from the 2nd protrusion part 25, and the rocking lever 9 and 2nd The suction force generated between the protrusion 25 and the protrusion 25 is smaller than the above-described value, and the swing lever 9 is not swung in the B direction by the second protrusion 25.

As described above, in the state where the rear end 9b of the swing lever 9 is in contact with the first protrusion 23, a gap remains between the swing lever 9 and the second protrusion 25. The size of the gap is larger than the gap between the swing lever 9 and the first protrusion 23 in a state where the key 7 is arranged at the initial position. Therefore, the swing lever 9 cannot be attracted to the second protrusion 25 only by the magnetic flux generated from the second protrusion 25.
However, in this state, the swing lever 9 is magnetized, and the middle portion of the swing lever 9 facing the second protrusion 25 has a magnetic pole opposite to the magnetic pole of the second protrusion 25. Become. In other words, in this state, the magnetic flux density between the second protrusion 25 and the swing lever 9 is such that the rear end 9b of the swing lever 9 is the first without changing the magnitude of the current flowing through the coil 19. It becomes larger compared to the state of being spaced apart from the one protrusion 23. Therefore, the key 7 and the swing lever 9 are further moved in the B direction against the biasing force of the biasing means 13 until the middle portion of the swing lever 9 comes into contact with the second protrusion 25 by the magnetic force of the electromagnet 11. Swing.

When the swing lever 9 swings in the B direction with the swing lever 9 in contact with the first protrusion 23, the electromagnet 11 swings in the C direction together with the swing lever 9, so that the swing While maintaining the state where the rear end 9b of the moving lever 9 is in contact with the first protruding portion 23, the swinging lever 9 is swung in the B direction so that the middle portion of the swinging lever 9 approaches the second protruding portion 25. Can be moved.
As described above, as shown in FIG. 4, the swing lever 9 comes into contact with the two protrusions 23 and 25 of the electromagnet 11. In this state, a magnetic path is formed in which the swing lever 9 is in contact with both of the two protrusions 23 and 25 so as to be closed. Can be set to about 1/3 of the magnitude of the current passed to swing the swing lever 9.
Further, when the supply of current to the coil 19 is stopped in a state where the swing lever 9 is in contact with the two protrusions 23 and 25 as described above, the key 7 or the swing is caused by the weight of the swing lever 9. The lever 9 is urged in the A direction and swings. As a result, as shown in FIG. 2, the key 7 returns to the initial position.

As shown in FIG. 1, the keyboard instrument including the key driving device 1 described above generates a musical sound corresponding to the music data output from the performance information generating device 3 in synchronization with the driving of the key 7 by the key driving device 1. Sounding means 33 is also provided. The sound generation means 33 includes a sound source 35 that stores actual waveform data having a pitch corresponding to each key 7 and various timbres, a sound generation device 37 that outputs waveform data, and a musical sound corresponding to music data from the sound source 35. And a sound generation control device 39 that controls the waveform data based on the sound generation timing information, note information, and other information of the music data, and outputs the waveform data from the sound generation device 37. Yes. Here, the sound generation device 37 corresponds to, for example, an amplifier or a speaker of an audio device.
Therefore, when each musical sound of the music data is output from the performance information generating device 3 to both the key drive control device 5 and the sound generation control device 39, the predetermined waveform data corresponding to each music sound is generated as the sound of the music data. Based on the timing information, note information, and other information, the sound generator 37 outputs the information.

The keyboard instrument also includes a key press detection device 31 that individually detects that each key 7 has swung in the B direction to a position where the swing lever 9 contacts the two protrusions 23 and 25 of the electromagnet 11. The detection result of the key depression detection device 31 is output to the sound generation control device 39. In this case, the sound generation control device 39 reads predetermined waveform data from the sound source 35 based on the detection result of the key press detection device 31 and causes the sound generation device 37 to output this waveform data. Therefore, when the predetermined key 7 is pressed with a finger and the swing lever 9 is swung to a position where it touches the two protrusions 23 and 25, the waveform data corresponding to the pressed key 7 is obtained from the sound generator 37. Will be output.
As described above, in this keyboard instrument, both automatic performance based on music data and manual performance by the performer are possible.

In the keyboard instrument configured as described above, an operation when performing an automatic performance will be described below.
As shown in FIG. 5, first, the performance information generating device 3 reads music data including pronunciation timing information and note information (step S1), and outputs each musical tone of the music data to the key drive control device 5 (step S1). S2). Specifically, each tone of the music data is output to the key drive control device 5 based on the sound generation timing information of the music data. Next, the key drive control device 5 controls the switch 29 of the key drive device 1 attached to the key 7 corresponding to the pitch of each musical tone based on the note information of the music data, so that the coil 19 of the electromagnet 11 is controlled. Current is passed (step S3). At this time, the swing lever 9 is attracted to the electromagnet 11 by the magnetic force and comes into contact with the two projecting portions 23 and 25 of the electromagnet 11. As a result, the key 7 corresponding to the musical sound swings in the B direction against the urging force of the urging means 13 from its initial position.
At this time, a current is continuously supplied to the coil 19 while the sound generation timing information is ON, that is, according to the musical sound length of the music data. That is, in accordance with the end of the musical tone of the music data, the key drive control device 5 controls the switch 29 to cut off the energization of the coil 19 by the power source 27. When the energization of the coil 19 is interrupted, the key 7 is swung in the A direction by the urging force of the urging means 13 and returned to the initial position.

Then, it is determined whether or not the musical sound of the music data to be output to the key drive control device 5 remains (step S4). If it is determined that the music data to be output remains, the process returns to step S2. The performance information generating device 3 outputs the next musical sound of the music data to the key drive control device 5. If it is determined in step S4 that no musical sound to be output remains in the music data, the driving of the key 7 based on the music data is terminated.
When each key 7 described above is driven, waveform data corresponding to the musical tone of the music data is output from the sound generator 37 to the sound generator 37 so as to synchronize with the driving of the key 7. That is, the sound generation control device 39 reads waveform data corresponding to the musical tone of the music data output from the performance information generating device 3 from the sound source 35, and this is read out from the sound generation timing information, note information and other information from the performance information generating device 3. Based on the information, the sound generator 37 outputs the controlled signal.

As described above, according to the key driving device 1 according to this embodiment, in the state where the current is passed through the coil 19 and the rear end 9b of the swing lever 9 is brought into contact with the first protrusion 23 of the electromagnet 11. The magnetic flux density between the second protrusion 25 and the swing lever 9 is larger than that in the state where the rear end 9b of the swing lever 9 is located away from the first protrusion 23. . For this reason, even if the current flowing through the coil 19 is reduced or the gap between the second projecting portion 25 and the swing lever 9 is large, the swing lever 9 is configured to swing the key 7 in the B direction. The magnetic force for attracting can be increased. Therefore, it is possible to obtain a sufficient initial driving force for driving the key 7 and to ensure a sufficient swing range of the key 7.
In this embodiment, the key 7 is arranged at the initial position with the rear end 9b of the swing lever 9 being separated from the first protrusion 23. By reducing the gap between the first protrusion 23 and the first protrusion 23, the rear end 9 b of the swing lever 9 is attracted to the first protrusion 23 by the magnetic force of the electromagnet 11 without increasing the current flowing through the coil 19. Enough power to do.
As described above, the initial driving force for driving the key 7 at the initial position of the key 7 can be sufficiently obtained even with power saving.

In addition, since the key driving device 1 is configured by only one electromagnet 11 and the swing lever 9, a case where the key driving device is configured by combining a solenoid, a stepping motor, and a gear mechanism as in the past. In comparison, the key drive device 1 and the keyboard instrument can be easily reduced in size and weight.
Further, since the swing lever 9 also has a role as a biasing means 13 that biases the key 7 in the A direction, the number of components of the key driving device 1 is reduced and the manufacturing cost is also reduced. be able to.

Further, by supporting the electromagnet 11 so as to be swingable with respect to the frame, the swing lever 9 is further swung in the B direction while the rear end 9b of the swing lever 9 is in contact with the first protrusion 23. In this case, since the state where the rear end 9b of the swing lever 9 is in contact with the first projecting portion 23 can be reliably held, when the rear end 9b of the swing lever 9 described above is swung, It is possible to reliably prevent the magnetic flux density between the second protrusion 25 and the swing lever 9 from decreasing.
Furthermore, since the second protrusion 25 is disposed at a position closer to the fulcrum F1 than the rear end 9b of the swing lever 9, even if the gap between the second protrusion 25 and the swing lever 9 is reduced. The swing range of the swing lever 9 and the key 7 engaged therewith can be increased.

Also, according to this keyboard instrument, the musical instrument 37 can generate musical sounds in synchronism with the driving of the key 7 based on the music data, so that the keyboard instrument can be automatically played with power saving.
Further, since each key 7 of the keyboard instrument can be swung in association with the music data, for example, the key 7 to be pressed by the finger by the movement of each key 7 can be notified to the player of the keyboard instrument. Therefore, the movement of each key 7 according to the music data can be directly felt with fingers as well as the eyes, and the music can be practiced efficiently.

In the keyboard instrument of the above embodiment, the waveform data is output from the sound generator 37 based on the music data and the detection result of the key press detection device 31. However, the present invention is not limited to this, and it is not output. It doesn't matter. In this case, for example, the music can be practiced without causing trouble to the surroundings.
Further, in the key driving device 1 of the above embodiment, the urging means 13 is configured by the swing lever 9, but is not limited thereto, and is configured to urge at least the key 7 in the A direction. It only has to be done. That is, the urging means may be constituted by an elastic member such as a coil spring or a leaf spring.

  Furthermore, although the electromagnet 11 is supported so as to be swingable with respect to the frame with the middle part of the iron core body 21 as a fulcrum F2, the present invention is not limited to this, and at least the rear end 9b of the swing lever 9 is the first. The swing lever 9 may be configured to be able to swing in the B direction while maintaining a state in contact with the protruding portion 23.

  Therefore, for example, as shown in FIGS. 6 to 8, a contact surface 57 a that contacts the rear end 9 b of the swing lever 9 is formed on the first projecting portion (one end portion) 57 of the iron core 55 constituting the electromagnet 53. The lock driving device 51 may be configured. Here, the contact surface 57 a is formed to extend in the swing direction of the swing lever 9. That is, the swing lever 9 swings from the position where the rear end 9 b of the swing lever 9 contacts the regulating member 15 to the position where the middle portion of the swing lever 9 contacts the second projecting portion (other end portion) 59 of the electromagnet 53. The rear end 9b of the lever 9 can be held in contact with the contact surface 57a. The electromagnet 53 is fixed to the frame. Similarly to the above embodiment, the second projecting portion 59 of the electromagnet 53 is opposed to the middle portion of the swing lever 9 through a gap when the swing lever 9 is in contact with the regulating member 15. Has been placed.

In the key drive device 51 having this configuration, when a current is passed through the coil 19 of the electromagnet 53 with the swing lever 9 in contact with the regulating member 15 as shown in FIG. The rear end 9b of the swing lever 9 is attracted to the contact surface 57a. Thereby, similarly to the above-described embodiment, the swing lever 9 is magnetized, and the middle portion of the swing lever 9 facing the second protrusion 59 is opposite to the magnetic pole of the second protrusion 59. Will have. That is, the magnetic flux density between the second protrusion 59 and the swing lever 9 is larger than that in the state where the rear end 9b of the swing lever 9 is located away from the first protrusion 57. Become.
As a result, as shown in FIG. 8, the key 7 and the swing lever 9 are resisted against the biasing force of the biasing means 13 until the middle portion of the swing lever 9 contacts the second protrusion 59. Will swing in the direction. Further, at the time of the swing, the rear end 9b of the swing lever 9 moves on the contact surface 57a.

Therefore, this lock driving device 51 also has the same effect as in the above embodiment. That is, even if the gap between the second protrusion 59 and the swing lever 9 is large, the swing lever 9 is attracted to the second protrusion 59 without increasing the current flowing through the coil 19 of the electromagnet 53. Can be sufficiently secured, and an initial driving force for driving the key 7 at the initial position of the key 7 can be sufficiently obtained.
Further, when the middle part of the swing lever 9 is attracted by the second protrusion 59 and the swing lever 9 moves in the B direction, the rear end 9b of the swing lever 9 is moved on the contact surface 57a. Therefore, the swing lever 9 can be swung in the B direction while reliably holding the contact between the rear end 9b of the swing lever 9 and the first protrusion 57. Therefore, it is possible to reliably prevent the magnetic flux density between the second protrusion 59 and the swing lever 9 from being reduced during the swing.

  In this key drive device 51, the rear end 9b of the swing lever 9 is directly brought into contact with the contact surface 57a of the first protrusion 57. However, the present invention is not limited to this. For example, as shown in FIG. Thus, a non-magnetic member having a small thickness (for example, about 1 mm in thickness) may be provided on the contact surface 57a. In this case, the rear end 9b of the swing lever 9 is disposed on the contact surface 57a via the non-magnetic member. Can be moved in the direction.

  Further, the first protrusion 57 is not limited to the formation of only one contact surface 57a. For example, as shown in FIG. 10, a parallel facing surface 57b is formed facing the contact surface 57a. It doesn't matter. Here, the gap between the contact surface 57a and the facing surface 57b is large enough to allow the rear end of the swing lever 9 to contact both the contact surface 57a and the facing surface 57b. In the case of this configuration, the movement of the swing lever 9 is restricted only in the A direction and the B direction by the contact surface 57a and the facing surface 57b, so that the swing lever 9 is separated from the first protrusion 57. Can be reliably prevented. Even in this configuration, the nonmagnetic member shown in FIG. 9 may be attached to both the contact surface 57a and the opposing surface 57b.

Although the electromagnets 11 and 53 are arranged to face the swing lever 9, the present invention is not limited to this. At least the biasing means for biasing the key 7 is used to attract B by the attraction force of the electromagnets 11 and 53. It only needs to be arranged at a position where it can swing in the direction. That is, the electromagnets 11 and 53 may be disposed to face the rear end 7b of the key 7, for example. In this case, for example, a substantially plate-like magnetic body such as a metal plate may be attached to the lower side of the rear end 7b of the key 7, and the electromagnets 11 and 53 may be disposed at positions facing the magnetic body. .
Even in the case of this configuration, the same effects as those of the above embodiment can be obtained. Further, since the urging means for urging the key 7 in the A direction is constituted by a coil spring or a leaf spring, a separate rocking lever 9 for rocking the key 7 becomes unnecessary, so that the key driving device By simplifying the configuration, it is possible to further reduce the size and weight of the keyboard instrument and reduce the manufacturing cost.

  Further, for example, a rod-shaped member as a magnetic body may be integrally formed in the longitudinal direction from the rear end 7b of the key 7, and the electromagnets 11 and 53 may be disposed at positions facing the rod-shaped member. In the case of this configuration, a fulcrum for swinging the key 7 and the rod-shaped member may be arranged at the boundary between the key 7 and the rod-shaped member. Further, by making the weight of the rod-shaped member heavier than the key 7, the rod-shaped member functions as a biasing means that biases the key 7 in the A direction. Therefore, even in the case of this configuration, the same effects as those of the above embodiment can be obtained.

  Furthermore, although the key drive device 1 of the above embodiment is mounted on a keyboard instrument including the sound generation means 33 that generates an electronic sound, the present invention is not limited to this, and a grand piano or an upright piano that strikes a string with a hammer. It does not matter if it is mounted on.

  As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.

It is a block diagram which shows the structure which drives a key and generate | occur | produces a musical tone based on music data in the keyboard musical instrument which concerns on one Embodiment of this invention. It is a schematic side view which shows the key drive device attached to the keyboard musical instrument which concerns on one Embodiment of this invention. FIG. 3 is a schematic side view showing a state in which a current is passed through a coil of an electromagnet in the key driving device of FIG. 2. In the keyboard musical instrument which concerns on one Embodiment of this invention, it is a schematic side view which shows the state which sent the electric current through the coil of an electromagnet. 5 is a flowchart for driving a key based on music data in a keyboard instrument according to an embodiment of the present invention. It is a schematic side view which shows the key drive device which concerns on other embodiment of this invention. FIG. 7 is a schematic front view showing a state in which the rear end of the swing lever is arranged on the contact surface of the electromagnet in the key drive device of FIG. FIG. 7 is a schematic side view showing a state in which a current is passed through a coil of an electromagnet in the key driving device of FIG. In the key drive device which concerns on other embodiment of this invention, it is a schematic front view which shows the state which has arrange | positioned the rear end of the rocking lever to the contact surface of an electromagnet. In the key drive device which concerns on other embodiment of this invention, it is a schematic front view which shows the state which has arrange | positioned the rear end of the rocking lever to the contact surface of an electromagnet.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,51 ... Key drive device, 3 ... Performance information generator, 5 ... Key drive control device, 7 ... Key, 9 ... Swing lever (magnetic body), 9b ... Rear end (end), 11, 53 ... electromagnet, 13 ... biasing means, 17, 55 ... iron core, 19 ... coil, 23, 57 ... first protrusion (one end) Part), 25, 59 ... second projecting part (other end part), 33 ... sound generating means, 57a ... contact surface, F1 ... fulcrum, F2 ... fulcrum

Claims (6)

A key driving device for driving a key supported to be swingable with respect to a frame,
Biasing means for biasing the key in one of its swing directions;
A magnetic body that swings relative to the frame in conjunction with the swing of the key;
The magnetic core is composed of a substantially U-shaped iron core and a coil wound around the iron core so that the key is swung in the other swinging direction while a current flows through the coil. An electromagnet that attracts the body with magnetic force,
An end portion of the magnetic body in which the one end portion of the iron core is located away from a fulcrum serving as a swing center of the magnetic body in a state where the magnetic body can swing in accordance with the other swinging direction of the key. And is in contact with the magnetic body,
A key driving device, wherein the other end portion of the iron core is disposed opposite to the magnetic body at a middle portion of the magnetic body located between the fulcrum and the end portion with a gap. . A key driving device for driving a key supported to be swingable with respect to a frame,
Urging means for urging the key in one of its swing directions;
The urging means is composed of a rod-shaped magnetic body that oscillates with respect to the frame in conjunction with the oscillating of the key, and urges the key in the one oscillating direction by its own weight,
An electromagnet composed of a substantially U-shaped iron core and a coil wound around the iron core is made to oscillate the key in the other oscillating direction while a current flows through the coil. Arranging the magnetic body at a position to be attracted by magnetic force,
An end portion of the magnetic body in which the one end portion of the iron core is located away from a fulcrum serving as a swing center of the magnetic body in a state where the magnetic body can swing in accordance with the other swinging direction of the key. And is in contact with the magnetic body,
A key driving device, wherein the other end portion of the iron core is disposed opposite to the magnetic body at a middle portion of the magnetic body located between the fulcrum and the end portion with a gap. . 3. The key driving device according to claim 1, wherein the electromagnet is swingable with respect to the frame with a middle portion of the iron core as a fulcrum. 4. The electromagnet is fixed to the frame;
A contact surface in contact with the magnetic body is formed at one end of the iron core,
3. The key driving device according to claim 1, wherein the contact surface extends in a rocking direction of the magnetic body interlocked with the other rocking direction of the key. A keyboard instrument in which a plurality of keys supported so as to be swingable with respect to the frame are arranged side by side,
The key driving device according to any one of claims 1 to 4 , which drives each key;
A performance information generator for generating music data for automatic performance;
A keyboard instrument comprising: a key drive control device for causing a current to flow through a coil of the electromagnet corresponding to the key selected based on the music data. 6. The keyboard instrument according to claim 5 , further comprising sound generation means for generating a musical sound so as to synchronize with the driving of the key based on the music data.

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