JPS5939759Y2 - Electromagnetic buzzer - Google Patents

Description

[Detailed explanation of the idea] (Technical field) The present invention relates to an electromagnetic buzzer.

(Prior art) As shown in Japanese Utility Model Application Publication No. 48-38776, a lower end flange of a coil bobbin is fixed on a circuit board, and a frame connected to a diaphragm placed above the coil bobbin is placed between the circuit boards. Since the end is bent upward through the cutout and inserted into the coil bobbin, the circuit board has a lot of dead space, which actually reduces the space available for circuit pattern design. It is necessary to design around the notch of the circuit board, and when it is attached to the case, the soldered part of the circuit board comes into contact with the case, so the structure takes into account the insulation structure, such as placing an insulating member between the two. Because of the need to make the structure smaller, it has the drawbacks of a complicated structure and poor assembly workability.

(Purpose) The present invention is designed so that the circuit board does not touch the magnetic board case and floats in the intermediate space, so that the soldered part of the circuit board is connected to the magnetic board.
The purpose is to reliably prevent short circuits due to contact with the case, improve assembly workability, minimize dead space on the circuit board, and make the entire circuit board compact and flat.

(Structure) In this invention, an iron core protruding from a magnetic board is fitted into a center hole of a coil bobbin around which a coil is wound, a part of the circuit board is fixed to the upper flange of the coil bobbin, and a space between the magnetic board and the diaphragm is Since the circuit board is made to protrude and float, the excitation circuit components are attached to the circuit board, and the magnetic board is fixed to the case, there is no chance that the soldered part of the circuit board will come into contact with the magnetic board or the case and cause a short circuit. It is characterized by being able to reliably prevent this, simplifying the structure, and improving assembly workability.

(Example) Next, an example of the present invention shown in the accompanying drawings will be described in detail.

Reference numeral 1 denotes a bowl-shaped case with a bottom made of synthetic resin, with a sound emitting hole 1a formed in the upper part, and a protrusion 1b protruding from the inner surface of the upper ball part, and using the protrusion 1b as a guide, a diaphragm 2, a spacer 3, The diaphragm 4 is sequentially superposed and the tip of the projection 1b is caulked.

5 is a bobbin wound with a coil 6, an upper collar 5A and a lower collar 5.
B is integrally formed, and further protrusions 5a and 5b are provided.

Reference numeral 7 denotes a circuit board on which electrical parts such as a transistor 8, a resistor 9, a diode 10, etc. that constitute an excitation circuit are connected and attached as shown in Fig. 6. The guide holes 7a and 7b formed at predetermined positions are respectively fitted into the protrusion 5C and the protrusion 5a of the upper collar 5A of the bobbin 5, and the upper end of the protrusion 5a is caulked, or the protrusion 5c and the protrusion 5a are After determining the fitting position, the bobbin and the circuit board abutting part are fixed with an adhesive or both means, and the coil lead wire is terminally processed to form an electromagnetic drive part.

Reference numeral 12 is a magnetic member having a protruding iron core 13 formed thereon, and a mounting hole 12a to the case at a corner and a guide hole 12b near the iron core 13.

Then, apply adhesive to the lower flange 5B of the bobbin 5 of the electromagnetic drive section, fit the center hole 5D into the iron core 13, and lower the protrusion 5.
b is fitted and fixed into the guide hole 12b.

Next, the attachment hole 12a of the magnetic member 12 is fitted into the lower protrusion 1c of the case 1, and the protrusion 1c that protrudes from the magnetic member 12 is welded and caulked.

(Effects) According to the present invention, the iron core protruding from the magnetic board is fitted into the center hole of a coil bobbin around which a coil is wound, and a part of the circuit board is fixed to the upper flange of the coil bobbin, and a part of the circuit board is fixed between the magnetic board and the diaphragm. Since the circuit board is projected and floated in the space, the excitation circuit components are attached to the circuit board, and the magnetic board is fixed to the case, there is no chance that the soldered part of the circuit board will come into contact with the magnetic board case and cause a short circuit. It can reliably prevent this, the structure is simplified, and assembly workability is good, and the dead space of the circuit board is extremely reduced and the entire circuit board can be used effectively, so it can be made small and flat.

[Brief explanation of the drawing]

Fig. 1 is a front cross-sectional view of an embodiment of the present invention, Fig. 2 is a perspective view of the electromagnetic drive unit turned over, Fig. 3 is a perspective view of the iron core protruding from the base plate, and Fig. 4 is a front view of the case. 5 is a bottom view of the case, and FIG. 6 is an electric circuit diagram of the electromagnetic drive unit. 1...Case, 4...Diaphragm, 5...
...Bobbin, 5A...Bobbin upper flange, 5B
...Bobbin lower flange, 5a...Protrusion, 5
b... Protrusion, 6... Coil, 7...
...Circuit board, 12...Magnetic member, 13...
... Iron core.

Claims (1)

[Scope of utility model registration request] A core protruding from the magnetic board is fitted into the center hole of a coil bobbin around which a coil is wound, a part of the circuit board is fixed to the upper flange of the coil bobbin, and the circuit board is projected and floated in the space between the magnetic board and the diaphragm. , an electromagnetic buzzer in which excitation circuit components are attached to the circuit board, and the magnetic board is fixed to a case.