Driving device with double-coil electromagnet and piano automatic performance apparatus

Abstract

The utility model relates to piano playing device technical field, concretely relates to a driving device and piano automatic performance equipment with double coil electromagnet. The driving device includes interval arrangement's drive component and auxiliary assembly, and drive component includes first core and first coil module, and first coil module includes first support piece, first coil group to and the first sleeve of setting on both of them, and auxiliary assembly includes second core and second coil module, and second coil module includes second support piece, second coil group to and the second sleeve of setting on both of them, and first core is connected with second core through the connecting portion, and the length L1 of first core is greater than the length L2 of second core, and the length L3 of first coil group is greater than the length L4 of second coil group. The scheme can make the emission of piano in the performance process more fluent and improve the performance quality through the effective control of different stages of piano playing, especially the control of the sound stopping process of sound stopping cotton.

Description

Technical Field

[0001] This utility model relates to the field of piano playing device technology, specifically to a driving device with a double-coil electromagnet and an automatic piano playing device. Background Technology

[0002] The piano is a keyboard instrument in Western classical music, divided into grand pianos and upright pianos. It consists of 88 keys (52 white keys and 36 black keys) and a metal string soundboard. Pianos are widely used for solo, ensemble, and accompaniment performances, and are very convenient for composing and rehearsing music. The player presses the keys on the keyboard, which activates small felt-covered hammers inside the piano, striking the steel strings to produce sound. Pianos require regular maintenance to ensure their tone remains consistent.

[0003] Traditionally, the automatic playing mechanism of a piano typically uses an electromagnet. An electromagnet is a device that generates electromagnetic fields when an electric current is passed through it. A conductive winding, matching the power of the coil, is wound around the outside of an iron core. This current-carrying coil has magnetic properties, similar to a magnet, and can drive the movable iron core to move.

[0004] For example, utility model patent CN 215643915 U, entitled "An Electromagnet for an Automatic Piano Playing System," discloses an electromagnet for an automatic piano playing system. It includes a plastic nut with a foam rubber ring and a threaded tube mounted on it. A round iron tube is mounted on the threaded tube, and a movable iron core is located inside the round iron tube. A copper tube is located outside the movable iron core, and a round iron plate is located at the top of the round iron tube. An aluminum strip is located on the movable iron core, with its top end penetrating the round iron plate. A spool is located outside the copper tube, and enameled wire is located outside the spool. A conductor assembly is located on the spool. A rubber pad is located at the top of the aluminum strip, and a felt pad is located at the top of the rubber pad. However, this electromagnet drive device results in low quality automatic piano playing.

[0005] Therefore, it is necessary to improve upon existing technology and develop a new automatic piano playing drive to enhance the quality of automatic piano playing. Utility Model Content

[0006] The purpose of this invention is to provide a dual-coil electromagnet and an automatic piano playing device, which partially solves or alleviates the above-mentioned deficiencies in the prior art.

[0007] To solve the aforementioned technical problems, the present invention specifically adopts the following technical solution:

[0008] The first aspect of this utility model is to provide a driving device with a dual-coil electromagnet, the driving device comprising: a driving component and an auxiliary component spaced apart; the driving component comprising a first iron core and a first coil module disposed outside the first iron core; the first coil module comprising a first support member, a first coil group disposed around the first support member, and a first sleeve sleeved on the first coil group and the first support member; the auxiliary component comprising a second iron core and a second coil module disposed outside the second iron core; the second coil module comprising a second support member, a second coil group disposed around the second support member, and a second sleeve sleeved on the second coil group and the second support member; the first iron core is connected to the second iron core via a connecting portion, and the length L1 of the first iron core is greater than the length L2 of the second iron core, and the length L3 of the first coil group is greater than the length L4 of the second coil group; the driving device further comprises a buffer module, the buffer module comprising a first buffer member and a second buffer member, the first buffer member being connected to the first iron core via a push rod, and the second buffer member being connected to the first buffer member.

[0009] In some embodiments, an isolation portion is provided between the first sleeve and the second sleeve, the first surface of the isolation portion is connected to the first sleeve, the second surface of the isolation portion is connected to the second sleeve, and the interior of the isolation portion is provided with a space for the first iron core and the second iron core to reciprocate.

[0010] In some embodiments, the material of the isolation portion is a non-ferromagnetic material.

[0011] In some embodiments, the first coil group and the second coil group are respectively connected to a power supply for supplying power to them. When the first coil group is energized, the magnetic field generated by the first coil group can drive the first iron core to move within a first thread; when the second coil group is energized, the magnetic field generated by the second coil group can drive the second iron core to move within a second thread, wherein the first thread is larger than the second thread.

[0012] Furthermore, in some embodiments, the second thread is X2, and X2 ≤ 2 mm.

[0013] In some embodiments, the length L4 of the second coil group is 4-20 mm.

[0014] Preferably, in some embodiments, L4 is 6.4 mm.

[0015] In some embodiments, the number of turns N2 of the second coil group is 100≤N2≤2000.

[0016] In some embodiments, the distance between the first sleeve and the second sleeve is L5, the length of the connecting part is L6, the maximum distance of the first thread is X1, and the length of the first iron core extending beyond the first sleeve is H1. The L5, L6, X1 and H1 satisfy the following setting relationship: L5 = L6 + X1 + H1.

[0017] In some embodiments, L5 is 9 mm, L6 is 3 mm, X1 is 4 mm, and H1 is 2 mm.

[0018] In some embodiments, the connecting portion is made of a non-ferromagnetic material.

[0019] In some embodiments, both the first and second buffers are made of flexible materials.

[0020] In some embodiments, a housing is fitted onto the first iron core and the second iron core.

[0021] In some embodiments, the first sleeve and the second sleeve are made of iron.

[0022] Another aspect of this utility model is to provide an automatic piano playing device, the device including the aforementioned driving device, the piano including piano keys, and the driving device being connected to the end of the piano keys via the second buffer member.

[0023] In other embodiments, the drive device is connected to the hand-pressed end of the piano key via the second buffer.

[0024] Beneficial technical effects:

[0025] Existing electromagnet drive solutions based on iron cores cannot effectively control the damping process of the piano's damping cotton during automatic piano playing applications. This results in a monotonous and discontinuous sound production, preventing the playing of music with rich tones and leading to low quality of automatic playing and low fidelity in repetition.

[0026] This invention provides a separate master-slave drive scheme based on two-way control, and designs a drive device with a dual-coil electromagnet and an automatic piano playing device based on this scheme. By using a separate master-slave drive design for the drive component and auxiliary component, precise control of the movement distance of the first and second threads of the iron core is achieved (i.e., two-way control), thus effectively coordinating the control of the piano's sound production. Specifically, for the piano's sound production process, a long-short co-driving dual-thread control mode is set up. The first coil group in the drive component primarily drives the first iron core to control the rising distance (i.e., control of the first thread), and the second coil group in the auxiliary component assists in driving the second iron core to control the falling distance (i.e., control of the second thread). In other words, this scheme precisely controls the first and second threads through a separate co-driving dual coil group and a co-driving iron core. The first thread (long thread) controls the key pressing process, and the second thread (short thread) controls the muting process. The combination of long and short threads allows the piano to produce a smoother sound. This invention uses a simple structural design to control the sound production and muting during the automatic playing process of a piano, thereby making the music played more fluent and harmonious. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. The elements or parts in the drawings are not necessarily drawn to scale. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0028] Figure 1 This is a first structural schematic diagram of a driving device according to one embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the second structure of the driving device according to one embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the structure of an auxiliary component according to one embodiment of the present invention;

[0031] Figure 4a This is a schematic diagram showing the iron core rising to the first position according to one embodiment of the present invention;

[0032] Figure 4b This is a schematic diagram showing the iron core rising to the second position according to one embodiment of the present invention;

[0033] Figure 4c This is a schematic diagram showing the iron core rising to the third position according to one embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the third structure of the driving device according to one embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the structure of a drive component according to one embodiment of the present invention;

[0036] Figure 7 This is a simulated magnetic field line distribution diagram during the core rising process of one embodiment of the present invention;

[0037] Figure 8 This is a simulated magnetic field line distribution diagram of the iron core during its fall, hovering, and slow descent process, according to one embodiment of this utility model.

[0038] Summary of reference numerals in the attached drawings: First iron core 1, connecting part 10, first coil group 11, first support member 12, first sleeve 13, first upper top plate 130, first lower bottom plate 131, first side plate 132, top rod 14, isolation part 15, second iron core 2, second coil group 21, second support member 22, second sleeve 23, second upper top plate 230, second lower bottom plate 231, second side plate 232, first buffer member 3, second buffer member 4. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0040] In this document, suffixes such as "module," "part," or "unit" used to denote elements are used only for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, "module," "part," or "unit" can be used interchangeably.

[0041] In this document, the terms "upper," "lower," "inner," "outer," "front," "rear," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0042] In this document, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," and "connected," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0043] In this document, "and / or" includes any and all combinations of one or more of the listed related items.

[0044] In this article, "multiple" means two or more, that is, it includes two, three, four, five, etc.

[0045] As used in this specification, the term "about" typically means + / -5% of the value, more typically + / -4% of the value, more typically + / -3% of the value, more typically + / -2% of the value, even more typically + / -1% of the value, and even more typically + / -0.5% of the value.

[0046] In this specification, some embodiments may be disclosed in a range-bound format. It should be understood that this "range-bound" description is merely for convenience and brevity and should not be construed as a rigid limitation on the disclosed range. Therefore, the description of a range should be considered as having specifically disclosed all possible subranges and the individual numerical values ​​within that range. For example, a description of the range 1-6 should be considered as having specifically disclosed subranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and the individual numbers within that range, such as 1, 2, 3, 4, 5, and 6. This rule applies regardless of the breadth of the range.

[0047] Length: Unless otherwise stated, “length” as used herein means length along the axial direction of the first core or the second core.

[0048] See Figures 1-8This utility model provides a driving device with a double-coil electromagnet and an automatic piano playing device.

[0049] Example 1

[0050] This utility model provides a driving device with a dual-coil electromagnet, see [link to relevant documentation]. Figure 1 As shown, the driving device includes: a driving assembly and an auxiliary assembly spaced apart. The driving assembly includes a first iron core 1 and a first coil module disposed outside the first iron core 1. The first coil module includes a first support member 12, a first coil group 11 disposed around the first support member 12, and a first sleeve 13 sleeved on the first coil group and the first support member. The auxiliary assembly includes a second iron core 2 and a second coil module disposed outside the second iron core 2. The second coil module includes a second support member 22, a second coil group 21 disposed around the second support member 22, and a second sleeve 23 sleeved on the second coil group and the second support member. The first iron core 1 is connected to the second iron core 2 through a connecting part 10, and the length L1 of the first iron core is greater than the length L2 of the second iron core, and the length L3 of the first coil group is greater than the length L4 of the second coil group. The driving device also includes a buffer module, which includes a first buffer member 3 and a second buffer member 4. The first buffer member 3 is connected to the first iron core 1 through a top rod 14, and the second buffer member 4 is connected to the first buffer member 3.

[0051] In some embodiments, the first coil group or the second coil group is formed by winding wires on the first support or the second support.

[0052] In this article, the length L3 of the first coil group or the length L4 of the second coil group refers to the length of the winding area of ​​the coil group in the axial direction of the first or second iron core, rather than the length of the conductor itself.

[0053] In some embodiments, the first coil group 11 and the second coil group 21 are respectively connected to a power supply for supplying them. When the first coil group is energized, the magnetic field generated by the first coil group can drive the first iron core 1 to move in the first thread (i.e., the long thread); when the second coil group is energized, the magnetic field generated by the second coil group can drive the second iron core 2 to move in the second thread (i.e., the short thread), and the first thread is longer than the second thread.

[0054] In other words, this solution uses the first iron core and the second iron core to drive the first thread and the second thread (i.e., dual threads) to rise and fall respectively. With the combined effect of long and short threads, it achieves the effect of effectively controlling the piano's sound production.

[0055] Furthermore, in some embodiments, the second thread is X2 (e.g., Figure 4c (as shown), and X2≤2 mm.

[0056] Furthermore, in some embodiments, the distance between the first threads is no more than 4 mm.

[0057] In some embodiments, an isolation portion 15 is provided between the first sleeve 13 and the second sleeve 23. The first surface of the isolation portion is connected to the first sleeve, the second surface of the isolation portion is connected to the second sleeve, and the interior of the isolation portion is provided with a space for the first iron core 1 and the second iron core 2 to reciprocate.

[0058] In some embodiments, the material of the isolation portion is a non-ferromagnetic material.

[0059] In some embodiments, the push rod 14 is made of a material of sufficient strength, such as metal.

[0060] In some embodiments, the first support member 12 and the second support member 22 are made of plastic.

[0061] In some embodiments, the length L4 of the second coil group 21 is 4-20 mm.

[0062] Preferably, in some embodiments, L4 is 6.4 mm.

[0063] In some embodiments, the number of turns N2 of the second coil group 21 is 100≤N2≤2000.

[0064] In some embodiments, the length of the second iron core 2 is 13 mm.

[0065] In some embodiments, the length of the second support member 22 is 0.8 mm.

[0066] In some embodiments, the length of the second sleeve 23 is 12 mm.

[0067] In some embodiments, the distance between the first sleeve 13 and the second sleeve 23 is L5 (e.g., Figure 2 As shown), the length of the connecting part 10 is L6 (as shown). Figure 2 As shown), the maximum distance of the first thread is X1 (as shown). Figure 5 As shown), the first iron core 1 extends beyond the first sleeve 13 by a length of H1 (as shown). Figure 6 As shown), that is, the difference H1 between the lengths of the first iron core and the first sleeve, L5, L6, X1 and H1 satisfy the following setting relationship: L5 = L6 + X1 + H1.

[0068] In other embodiments, L5 is 9 mm, L6 is 3 mm, X1 is 4 mm, and H1 is 2 mm. Specifically, the length relationship between L6 and L5 can be adjusted according to the actual situation.

[0069] In some embodiments, the connecting portion 10 is made of a non-ferromagnetic material.

[0070] In some embodiments, both the first and second buffers are made of flexible materials.

[0071] Furthermore, in some embodiments, the first buffer is a pad, and its material can be a soft material such as wool felt, foam, or silicone.

[0072] In other embodiments, the second buffer is a pad cap, which may also be made of soft materials such as silicone, rubber, or foam.

[0073] In some embodiments, the first iron core 1 and the second iron core 2 are fitted with a shell.

[0074] Furthermore, in some embodiments, the outer shell is made of a non-ferromagnetic material, such as copper, titanium alloy, or stainless steel, which have low magnetic permeability, to increase the strength of the first and second iron cores.

[0075] In some embodiments, the first sleeve 13 and the second sleeve 23 are made of iron.

[0076] In some embodiments, the first sleeve 13 includes a first upper top plate 130, a first lower bottom plate 131, and a first side plate 132, wherein the length of the first upper top plate and the length of the first lower bottom plate are the same.

[0077] In some embodiments, the second sleeve 23 includes a second upper top plate 230, a second lower bottom plate 231, and a second side plate 232, the length of which is 2 mm.

[0078] The working principle of the drive device of this utility model is as follows:

[0079] Ascending process: When the first coil group is energized and the second coil group is de-energized, the first coil group will generate an attractive force on the first iron core. The electromagnetic field generated by this force causes the first iron core to experience a first upward force, driving the first iron core to gradually lift the second iron core, so that the first and second iron cores rise from a first position (e.g., Figure 4a As shown) it gradually rises to the second position (as shown) Figure 4b As shown), it eventually stops at the third position (as shown). Figure 4c (as shown)

[0080] Falling process: When the first coil group is de-energized and the second coil group is energized, the second coil group will generate an attractive force on the second iron core. The electromagnetic field generated by the second coil group causes the second iron core to be subjected to a second upward force. The second upward force is in the same direction as the first upward force and is less than the first upward force, so as to control the second iron core to drive the first iron core to gradually fall. This causes the first and second iron cores to slowly fall from the third position. Finally, the second iron core is attracted by the second coil group and suspended, while the first and second iron cores stop at the second position.

[0081] The driving device of this invention reduces the current applied to the second coil group within the second thread of the second iron core, causing the positions of the first and second iron cores to change accordingly and hover.

[0082] This utility model is based on a two-way control split master-slave drive design, which means that the drive component controls the rising process of the iron core (referring to the first iron core and the second iron core). This is mainly achieved by energizing the first coil group to drive the first iron core to rise and thus drive the second iron core to rise. The auxiliary component mainly assists in driving the falling process of the iron core. This is mainly achieved by energizing the second coil group to drive the second iron core to fall and thus drive the first iron core to fall. This allows for effective control of the movement process of the iron core under the specific working mode of this solution.

[0083] In particular, the design of the damping process of the damping cotton on the piano is specifically designed to enable the drive device to produce smoother piano sounds and improve the performance quality during automatic piano playing. This solution features the design of auxiliary components, especially the precise control of the second thread of the second coil group. This allows for more flexible control of the damping process of the piano's damping cotton, thereby effectively controlling the damping process and making the piano sound smoother. It can produce reverberation or sounds with special timbre, enriching the techniques of automatic piano playing.

[0084] The implementation of the specific driving mode of master-slave drive in this scheme is also related to the spacing between the driving component and the auxiliary component, as well as the specific length or distance settings of the first coil group, the second coil group, the first iron core, and the second iron core. This allows the first iron core to drive the second iron core to rise together when the first coil group is energized, and the interaction between the iron cores has almost no impact on the rising process. Similarly, when the second coil group is energized, the second iron core drives the first iron core to fall back together, and the interaction between the iron cores has almost no impact on the falling process.

[0085] This utility model also provides an automatic piano playing device, the device including the above-mentioned driving device, the piano including piano keys, and the driving device being connected to the end of the piano keys through the second buffer 4.

[0086] In other embodiments, the drive device is connected to the hand-press end of the piano key via the second buffer 4.

[0087] In some embodiments, when using the automatic piano playing device:

[0088] The process of pressing the piano keys: When the first coil group is energized and the second coil group is de-energized, the first coil group will generate an attractive force on the first iron core. The electromagnetic field generated by it causes the first iron core to be subjected to a first thrust, which drives the first iron core to drive the second iron core and the push rod to gradually rise, and finally stop at the first playing position where the push rod can press the piano key. At this time, the strings can be struck to produce sound.

[0089] Mute process: When the first coil group is de-energized and the second coil group is energized, the second coil group will generate an attractive force on the second iron core. The electromagnetic field generated by the second coil group causes the second iron core to be subjected to a second thrust. The first thrust and the second thrust are in the same direction, and the second thrust is less than the first thrust. This controls the second iron core to drive the first iron core and the push rod to gradually fall, so that the first iron core and the second iron core slowly fall from the first playing position. Finally, the second iron core is attracted by the second coil group and suspended, so that the first iron core and the second iron core stop at the first falling position. At this time, the piano's damping cotton applies a certain pressure to the strings, so that the strings do not completely stop vibrating and can still produce sound.

[0090] In other words, in this embodiment, the directions of the first thrust and the second thrust are both opposite to the direction of gravity of the iron core (first iron core and second iron core), which can overcome the gravity of the iron core and better control the movement process of the iron core. The magnitude of the second thrust is less than one-tenth of the first thrust. The second thrust can make the iron core fall back slowly, thereby effectively controlling the time and force of the silence.

[0091] In other words, this solution enables simple and precise control over the damping process of the damping cotton, greatly improving the quality of the player piano's performance and the fidelity of its repetitions.

[0092] Furthermore, within the second thread of the second iron core described in this device, that is, during the process of the second iron core driving the first iron core and the push rod to gradually fall by about 2 mm, the damping cotton can change from a state of being detached from the strings to a state of being in contact, and the pressure can gradually increase. Finally, the strings are completely pressed down by the damping cotton, and the vibration stops. At this time, the piano stops making a sound.

[0093] Meanwhile, the area within the second thread of the second iron core is also a key area for the piano keys to fall back.

[0094] In some embodiments, when the first coil group is energized, the simulation diagram of the magnetic field lines of the first and second iron cores during the rising process is as follows: Figure 7 As shown, when the first iron core and the first upper plate approach to form a closed loop, the magnetic field lines are denser, and the attraction is stronger. Furthermore, the greater the vertical component of the magnetic field lines, the stronger the attraction. As the first iron core rises from its position near the first upper plate to above it, the vertical component of the magnetic field lines decreases, and the force also decreases.

[0095] In other embodiments, see Figure 8 The diagram shows a simulation of the magnetic field lines of the first and second iron cores during their descent, hovering, and slow descent when the second coil group is energized.

[0096] See Figures 7-8 This verifies the importance of the positional relationship between the separate master-slave drive (drive component and auxiliary component) designed in this scheme. It satisfies L5 = L6 + X1 + H1, which can effectively control different stages of piano playing (keying process and muting process) in the actual use process under the cooperation of drive component and auxiliary component. This makes the piano sound more continuous and smooth during the performance, and improves the musical quality of automatic piano playing.

[0097] In summary, this invention provides a separate master-slave drive scheme based on two-way control, and designs a drive device with a dual-coil electromagnet and an automatic piano playing device based on this scheme. By using a separate master-slave drive design for the drive component and auxiliary component, precise control of the movement distance of the first and second threads of the iron core is achieved (i.e., two-way control), thereby effectively coordinating the control of the piano's sound production. Specifically, for the piano's sound production process, a long-short co-driving dual-thread control mode is set up. The first coil group in the drive component primarily drives the first iron core to control the rising distance (i.e., control of the first thread), and the second coil group in the auxiliary component assists in driving the second iron core to control the falling distance (i.e., control of the second thread). In other words, this scheme precisely controls the first and second threads through a separate co-driving dual coil group and a co-driving iron core. The first thread (long thread) controls the key pressing process, and the second thread (short thread) controls the muting process. The combination of long and short threads allows the piano to produce a smoother sound. This invention uses a simple structural design to control the sound production and muting during the automatic playing process of a piano, thereby making the music played more fluent and harmonious.

[0098] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0099] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A driving device with a dual-coil electromagnet, characterized in that, The driving device includes: a driving assembly and an auxiliary assembly spaced apart. The driving assembly includes a first iron core (1) and a first coil module disposed outside the first iron core (1). The first coil module includes a first support member (12), a first coil group (11) disposed around the first support member (12), and a first sleeve (13) sleeved on the first coil group and the first support member. The auxiliary assembly includes a second iron core (2) and a second coil module disposed outside the second iron core (2). The second coil module includes a second support member (22), a second coil group (21) disposed around the second support member (22), and a second sleeve (23) sleeved on the second coil group and the second support member. The first iron core (1) is connected to the second iron core (2) through a connecting part (10), and The length L1 of the first iron core is greater than the length L2 of the second iron core, and the length L3 of the first coil group is greater than the length L4 of the second coil group; the driving device also includes a buffer module, which includes a first buffer (3) and a second buffer (4). The first buffer (3) is connected to the first iron core (1) through a top rod (14), and the second buffer (4) is connected to the first buffer (3); the first coil group (11) and the second coil group (21) are respectively connected to a power supply for supplying them. When the first coil group is energized, the magnetic field generated by the first coil group can drive the first iron core (1) to move in the first thread; when the second coil group is energized, the magnetic field generated by the second coil group can drive the second iron core (2) to move in the second thread, and the first thread is greater than the second thread.

2. The driving device according to claim 1, characterized in that, An isolation section (15) is provided between the first sleeve (13) and the second sleeve (23). The first surface of the isolation section is connected to the first sleeve, and the second surface of the isolation section is connected to the second sleeve. The interior of the isolation section is provided with a space for the first iron core (1) and the second iron core (2) to reciprocate.

3. The driving device according to claim 1, characterized in that, The second thread is X2, and X2 ≤ 2 mm.

4. The driving device according to claim 1, characterized in that, The length L4 of the second coil group (21) is 4-20 mm; and / or the number of turns N2 of the second coil group (21) is 100≤N2≤2000.

5. The driving device according to claim 1, characterized in that, The distance between the first sleeve (13) and the second sleeve (23) is L5, the length of the connecting part (10) is L6, the maximum distance of the first thread is X1, and the length of the first iron core (1) extending beyond the first sleeve (13) is H1. L5, L6, X1 and H1 satisfy the following setting relationship: L5=L6+X1+H1.

6. The driving device according to claim 1, characterized in that, The connecting part (10) is made of non-ferromagnetic material.

7. The driving device according to claim 1, characterized in that, Both the first and second buffer components are made of flexible materials.

8. The driving device according to claim 1, characterized in that, The first iron core (1) and the second iron core (2) are fitted with outer shells.

9. An automatic piano playing device, characterized in that, The device includes the drive device according to any one of claims 1-8, the piano includes piano keys, and the drive device is connected to the end of the piano keys via the second buffer (4); or, the drive device is connected to the hand-press end of the piano keys via the second buffer (4).

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