Key driving device for realizing automatic playing of piano

Abstract

The invention relates to the technical field of music instruments and specifically relates to a piano key automatic playing device, in particular to a device for driving piano keys to play automatically through electromagnets, which is characterized in that the vertical frame electromagnets with serrated distribution and arrangement are connected on the front surface and the back surface of a vertical mounting plate respectively, an ejector rod of each frame electromagnet penetrates an independent ejector rod hole of a piano middle plate, a buffer cap is inserted in the part at the top end ofthe upper surface of the middle plate, a row of intermittent kidney-shaped slot penetrating screws are arranged at the upper part of the mounting plate for connecting a plurality of adapter angles onthe front surface and the back surface of the mounting plate respectively, a plurality of rows of equidistant intermittent kidney-shaped slots are arranged between the upper part and the lower part of the mounting plate, and the penetrating screws connect the frame electromagnets on the front surface and the back surface of the mounting plate respectively. Compared with the prior art, the device has the advantages of novel design, firm structure, reliable use, convenient manufacture, small affects on the piano structure, no damage to the piano middle plate, low cost, simple production and mounting, strong versatility, large power margin of the electromagnets and easy heat dissipation.

Description

technical field [0001] The invention relates to the technical field of musical instruments, in particular to a device for automatically playing piano keys, in particular to a device for automatically playing piano keys driven by electromagnets. Background technique [0002] The piano is an expensive and precise acoustic instrument with high requirements for stability and constant temperature and humidity. The keyboard is generally composed of 88 keys. There is a positioning fulcrum in the middle of a single key. When the front end of the key is played by a human hand, the end of the key is warped rise. When the control circuit composed of a single-chip microcomputer drives the electromagnet iron core to move upward, the end of the key is lifted up, and the front end of the key moves downward, so that the key simulates the action of the finger when playing. A piano with this function is usually called an automatic player. piano. Due to the dense arrangement of the keys of t...

AI Technical Summary

Problems solved by technology

The single-row arrangement structure is simple, but the width of the electromagnet must not be greater than the width (gap) of the end of the key, the volume is limited, the iron core is too small, in order to enhance the power, the cost of making it with a special strong magnetic material is high, and it is arranged in a row. The hole density of the ejector rod in the middle plate of the piano is high, which may cause the hidden danger of deformation or even fracture of the middle plate

The vertical double-column type installs the electromagnets into upper and lower rows, which increases the volume of the electromagnets and increases the power. The disadvantage is that the lengths of the ejector pins of the upper and lower electromagnets are different, and the interchangeability is poor; the density of the ejector pins of the middle plate arranged in a row is high. , there is also a hidden danger of deformation or even breakage of the middle plate; and after the upper and lower electromagnets are integrated, the vertical dimension is long, which affects the vision. Some saw the middle plate to form a strip groove, and the electromagnet can be inserted into the middle plate. , although the vision has been improved, the strip grooves across the middle plate are more destructive to the piano structure, and are more likely to cause the middle plate to deform or even break

Japan's Yamaha company has a key drive device with planar double row electromagnets. If it is too high, the middle board must be excavated or the key part shall be sawn thin to make up for the lack of space, which is too destructive to the piano; the magnetic flux of this scheme is too small, so the voltage must be increased to increase the power; another deficiency is the gap between the keyboard and the middle board. The interlayer space is narrow, the air is not easy to convect, and the heat dissipation is poor. Thermal expansion can easily cause deformation and cracking of wooden parts, which will affect the stability of the piano. High temperature will also easily aging or even damage the circuit components.

Some units in China use cylindrical electromagnets and planar double-row sawtooth-arranged key drive devices. Due to structural limitations, it is also necessary to saw a strip-shaped groove that traverses the left and right sides of the piano with a thickness of about 4 cm. Greater impact on stability and integrity

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