JPH0136760B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electromagnetic pickup cartridge, and an object thereof is to provide an electromagnetic pickup cartridge that is easy to assemble and causes less mechanical distortion.

Among the electromagnetic pick-up cartridges, the most popular type today is the moving magnet type, due to its stable performance and ease of needle replacement. (below
A typical example is the MM type cartridge. In addition, moving iron type (hereinafter referred to as
Cartridges (referred to as MI type) are also popular. In order to improve the performance of these electromagnetic pick-up cartridges, such as the MM type and MI type cartridges, in order to more faithfully transmit the vibrations of the stylus tip received from the record, the stylus tip cantilever, armature air,
It is important to improve the vibrating parts such as dampers. In recent years, the characteristics of these vibrating parts have been considerably improved through the development of new materials. but,
We must not only improve the vibrating part, but also improve the performance of the power generation part that converts the mechanical vibration generated by this vibrating part into electrical signals.
It is impossible to improve the performance of the cartridge.

One channel of the conventional stereo type electromagnetic pickup cartridge shown in FIG. 1 is shown. In FIG. 1, a needle tip 1, a cantilever 2,
The magnet 3 and damper 4 constitute a vibrating part, and this vibrating part is movably held in a sleeve 5 made of a non-magnetic material via the damper 4. The sleeve 5 is removably inserted between two corks 8 and 9 made of overlapping thin plates made of magnetic material, and the coil 6 is wound around a coil bobbin 7 attached to one yoke 9. There is.

In the above configuration, the mechanical vibration caused by the sound groove of the record is transmitted to the vibrating part via the stylus tip 1, and is transmitted to the magnetic circuit (power generation part) consisting of the yokes 8, 9 and the coil 6 by the vibration of the magnet 4. , are taken out as electrical signals from both ends of the coil 6. This operation is performed in the same way for the left channel and the right channel in a stereo type pickup cartridge.

By the way, the coil bobbin 7 on which the coil 6 is wound
The yokes 8 and 9 are generally formed from separate parts, and when assembling the coil bobbin 7, on which the coil 6 has been wound in advance, is inserted into the yoke 9, and then the yoke 8 is inserted into the yoke 9 again. Due to the sharp edges, assembly is extremely difficult.
Further, as the gap between the yokes 8, 9 and the coil bobbin 7 widens, it becomes difficult to determine the positions of the coil bobbin 7 and the yokes 8, 9, which adversely affects the characteristics.

In order to solve these problems, winding the coil directly around the yoke has also been practiced. However, direct winding in this way often has a negative effect on performance, such as shorting between the yoke and the coil, or the coil shape is not fixed, and it also becomes difficult to work, leading to increased costs. .

The present invention provides an electromagnetic pickup cartridge that overcomes these conventional drawbacks. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to drawings of one embodiment.

FIGS. 2 and 3 show an embodiment of the power generation portion used in the electromagnetic pickup cartridge of the present invention. The difference from the one in Figure 1 is that resin is molded directly onto a part of the yoke 12, which is formed into a U-shape by stacking thin plates made of magnetic material, and the stacked plates are fixed so that they do not fall apart. ,
A coil bobbin 10 consisting of a coil winding trunk 10a having a substantially circular cross section and a flange 10b regulating the position of the coil winding is simultaneously formed on a part of the yoke 12 having a substantially rectangular cross section by integrally molding the resin. The coil winding body 10 of this coil bobbin 10
At point (a), the coil 11 is wound so as to pass through the front opening of the yoke 12 each time.

In this way, since the coil bobbin 10 is integrally molded on the multilayer yoke 12, there is no need to insert two things, the coil bobbin 7 and the yoke 8, into the yoke 9, as in the conventional example shown in FIG. Moreover, a coil-wound trunk portion 10a and a flange portion 10b having a substantially circular cross section are formed on a part of the yoke 12 having a substantially rectangular cross section.
, the coil 11 is easy to wind.
Furthermore, since a continuous yoke without any joints can be used as the yoke, assembly work can be significantly facilitated. Furthermore, resonance due to dislocation of the multilayer yoke can be suppressed to a minimum, and the cap between the yoke and the coil bobbin can also be suppressed to a minimum, thereby improving performance. Furthermore, since the positions of the yoke 12 and the coil bobbin 10 are maintained with high precision, assembly by automatic machines is also possible.
Cost reduction can also be expected.

As described above, in the electromagnetic pick-up cartridge of the present invention, a coil bobbin is formed by integral molding of resin on a part of the surface of the yoke, and a coil is wound around the coil-wound body of the coil bobbin, so that assembly work is simplified. can be improved and performance can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional example, and FIGS. 2 and 3 are a perspective view and a side view of essential parts of an embodiment of the present invention. 1... Needle tip, 2... Cantilever, 3...
...Magnet, 4...Damper, 5...Sleeve, 10...Coil bobbin, 11...Coil, 1
2...Yoke, 10a...Coil-wound body, 10
b...Tsubabe.

Claims (1)

[Claims] 1 Molding resin on a part of the surface of a substantially U-shaped yoke made by overlapping thin plate materials made of magnetic material to integrate the yoke and the resin, and molding a cross section on a part of the yoke having a substantially rectangular cross section. A coil bobbin having a substantially circular coil winding body and a flange for regulating the position of the coil winding is simultaneously formed by molding the resin, and a coil is wound around the coil winding body of this coil bobbin. Features an electromagnetic pick-up cartridge.