JPH0128630Y2 - - Google Patents

Description

[Detailed description of the invention] Figure 1 shows an electric guitar that converts mechanical vibrations applied to the strings into electrical vibrations using a piezoelectric transducer using a piezoelectric cable to operate an amplifier and speaker system. As shown, the flat bottom surface is seated in the concave groove B' of the bridge base B fixed on the top deck (not shown) of the guitar body, and the chevron-shaped top surface is in contact with the strings (not shown). A piezoelectric transducer R that is lightly pressed by a string bridge F having a surface F′
The piezoelectric cable P, which forms the core of the device and extends forward, is normally connected to the amplifier/speaker system by passing through a small hole (not shown) provided in the top deck, but it has flexibility as a piezoelectric element. Piezoelectric cables that use a polymer composite piezoelectric material made by dispersing fine powder of piezoelectric ceramics in rubber or plastic have a large capacitance and associated electrical loss, so they can be shortened to reduce capacitance. It was necessary to connect to a small lead wire L.

Therefore, it is necessary to shorten the piezoelectric cable as much as possible and connect it to the lead wire below the top deck of the guitar body or in the immediate vicinity of the guitar. It was desired that the connection be as strong as possible, since it is exposed to severe vibrations and there is a risk of wire breakage.

The present invention was devised to meet such demands, and the embodiments shown in the drawings will be described below.

In Fig. 2, P denotes a piezoelectric cable, which is made of a large number of twisted metal wires and is made of a high-quality material made of flexible rubber or plastic with fine piezoelectric ceramic powder dispersed around the outer periphery of the core wire 1, which also serves as a center electrode. A piezoelectric cable P is formed by sequentially covering a piezoelectric layer 2 made of a molecular composite piezoelectric material and a metal braid 3 that also serves as an outer electrode.
An outer shell H made of a flexible material such as rubber or plastic is applied to one side of the piezoelectric transducer R to be housed in the groove B' of the bridge base B in FIG. It can be formed by molding or the like on the end face of the piezoelectric cable P, or by molding it integrally with the piezoelectric cable P and then peeling it off, leaving the part accommodated in the groove B' of the bridge base.

L indicates a lead wire connected to an amplifier (not shown), and around a core wire 11 made of a large number of twisted metal wires, there is an insulating inner layer 12 made of flexible rubber or plastic, etc., a metal braid 13, and the above-mentioned wire. It consists of an insulating inner layer 12 and an insulating outer layer 14 of the same quality that are sequentially coated.

Next, C indicates the connecting portion between the piezoelectric cable P and the lead wire L, and in this case, the core wire of the piezoelectric cable and the lead wire protrudes inward from the opposing end surfaces of the two and is connected by soldering S or the like. 1 and 11
is covered and insulated by a heat-shrinkable tube 21, and further surrounds the insulated core wires 1 and 11 from the outside, and one end is fitted and fixed to the end 3a of the metal braid 3 (outer electrode) of the piezoelectric cable P. The piezoelectric cable P and the lead wire L are connected to each other by a metal tube 22 whose other end is fitted and fixed to the end 13a of the metal braid 13 which is exposed by peeling off the insulating outer layer 14 of the lead wire L and folded back to the outer peripheral surface of the insulating outer layer. mechanically connecting the two ends 22a, 22a of the metal tube and the piezoelectric cable P,
The fitting portions of the lead wires L with the respective metal braids 3 and 13 are hermetically covered with a heat-shrinkable tube 23.

In addition, when covering the heat-shrinkable tube 21, the piezoelectric cable has a larger inner diameter than the insulating outer layer 14 of the lead wire covered with the metal braid 3 of the piezoelectric cable or the folded metal braid layer 13. Insulating outer layer 14 of metal braid 3 or lead wire
After connecting the piezoelectric cable and the core wires 1 and 11 of the lead wire with the piezoelectric cable inserted through either of the above, the both ends 21a, 21a of the heat shrink tube 21 are connected to the inner end 2a of the piezoelectric layer 2 of the piezoelectric cable and the insulation of the lead wire. inner layer 1
2 and heated by sliding it so that it is located on the inner end 12a of
The metal tube 22 is shrunk to form an insulating coating layer 21.
Electrical continuity and mechanical connection are achieved by surrounding the outer periphery of the insulating layer 21 with a metal tube 22 that has previously been inserted through either the metal braid 3 of the piezoelectric cable or the insulating outer layer 14 of the lead wire, similar to the heat-shrinkable tube 21. The inner end 3a of the metal braid 3 of the piezoelectric cable and the folded part 13a of the metal braid layer 13 of the lead wire are coated with adhesives 24, 24 such as epoxy resin as necessary. 22a
Press and fix by rolling etc. Also,
The same method is used when covering the fitting portion between the metal tube 22, the piezoelectric cable, and the lead wire with the heat shrink tube 23.

As described above, the piezoelectric cable is made up of a piezoelectric transducer that converts string vibration into an electrical signal with an insulating outer shell on one side, and the electrical signal induced by the piezoelectric transducer is transmitted to the amplifier/speaker system. When connecting lead wires to be transported, this method involves insulating the core wires of the piezoelectric cable and the lead wire, which are connected by protruding from their opposing ends, with a heat-shrinkable tube, and then surrounding this insulated core wire. The piezoelectric cable and the lead wire are connected at both ends by a metal tube fitted into the end of the metal braid of each of the piezoelectric cable and the lead wire, and the fitting portion between both ends of the metal tube and the metal braid is connected with a heat-shrinkable tube. Because it is airtightly protected by a metal pipe, it firmly maintains the connection between the piezoelectric cable and the lead wire even in the face of severe vibrations, preventing failures such as loosening of the connection and disconnection. At the fitting parts of piezoelectric cables and lead wires with each metal braid, the minute gaps formed by the unevenness of the braid surface are hermetically covered with a heat shrink tube, so there is no possibility of insulation deterioration due to moisture intrusion. In addition to significantly improving durability by preventing the occurrence of rust, heat-shrinkable tubes with good workability can be used to cover the core wires of piezoelectric cables and lead wires, and to cover the fitting parts of metal tubes. Since it is used, it brings excellent profits in terms of mass production.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway perspective view illustrating the piezoelectric cable of an electric guitar's piezoelectric transducer through the connection part to the lead wire, and Figure 2 is an enlarged longitudinal section showing the main parts of the present invention. It is a front view. R...Piezoelectric transducer, P...Piezoelectric cable, 1...
...Core wire, 2...Piezoelectric layer, 3...Metal braid, L...
Lead wire, 11... Core wire, 12... Insulating inner layer, 1
3...Metal braid, 14...Insulating outer layer, C...Connection portion, 21, 23...Heat-shrinkable tube, 22...
metal tube.

Claims (1)

[Scope of utility model registration request] The outer periphery of the core wire, which also serves as the center electrode, is sequentially covered with a piezoelectric layer made of a polymer composite piezoelectric material, and a metal braid, which also serves as the outer electrode.An insulating outer shell is provided on one side of the core wire, which converts guitar string vibrations into electrical signals. A piezoelectric cable constitutes a piezoelectric transducer that converts into a piezoelectric transducer, and a core wire is coated with an insulating inner layer, a metal braid, and an insulating outer layer in order, and the electrical signal induced by the piezoelectric transducer is conveyed to an amplifier/speaker system. When connecting the piezoelectric cable and the lead wire, the core wires of the piezoelectric cable and the lead wire, which are connected by protruding from their opposing ends, are insulated with a heat-shrinkable tube, and the insulated core wire is further surrounded and connected at both ends. The piezoelectric cable and the lead wire are connected by a metal tube fitted to the end of the metal braid of each of the piezoelectric cable and lead wire, and the fitting portion between both ends of the metal tube and the metal braid is airtight with a heat-shrinkable tube. The connection part between the electric guitar's piezoelectric cable and the lead wire is protected by a protective covering.