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DESCRIPTION OF THE PREFERRED EMBODIMENT Cartridge 1, an armature coupled to a
vibrator, a coil, a magnetic circuit and a magnetic circuit, the armature is disposed in the air gap
of the magnetic circuit, and an output corresponding to the vibration of the vibrator is obtained.
A cartridge characterized in that at least one portion of the magnetic circuit is made of a nonmagnetostrictive amorphous magnetic metal body so as to be taken out from the coil. 2. The
cartridge according to claim 1, wherein the magnetic circuit comprises a pole piece portion
having the air gap and a short core portion connected to the pole piece portion through the leg
portion. 3. The cartridge according to claim 2, wherein the short core portion is formed of a nonmagnetostrictive amorphous magnetic metal. 4. The cartridge according to the items 2 and 3,
wherein the short core portion is formed by laminating a plurality of thin plates. 5. The cartridge
according to claim 2, wherein the pole piece portion is formed of a non-magnetostrictive
amorphous magnetic metal. 6. The cartridge according to any one of items 2 and 5, wherein the
pole piece portion is formed by laminating a plurality of thin plates.
DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cartridge for use
in a record player, and in particular, to improve its magnetic characteristics. As is well known, the
pickup coil is disposed in a magnetic circuit in which a magnetic flux magnetized by a magnet
flows, as known, and a signal is reproduced from the coil by a change in magnetic flux passing
through the magnetic circuit based on the vibration of the armature. It is supposed to be In this
case, as the magnetic material constituting the magnetic circuit, it is desirable that the saturation
magnetization Bs and the magnetic permeability μ be respectively large, and the squareness
ratio B7B and the coercivity Hc be each a ratio. Br is residual magnetization. As a result, it is said
that the dynamic range and the reproduction output become as large as EndPage: 1 and the
linearity is improved, and the phase difference of the output is small because Hc is reduced. It is
also known that the higher the resistivity of the magnetic material, the smaller the eddy current
loss, and the better the frequency characteristics. Permalloy has been used as a magnetic
material that constitutes a magnetic circuit used in a conventional cartridge, from this point of
view. Here, an example of a stereo cartridge will be described with reference to FIGS. 1 and 2 for
a movable magnet type so-called MM type. (1) is a cartridge housing, (2) is a vibrating body, ie, a
cantilever, (3) Is a stylus attached to its tip, (4) is an armature or magnet attached to the
cantilever (2), and (5) is a damper. The magnetic circuit (6) for the magnet (4) is configured as
follows. That is, as shown in FIG. 2, four pole piece portions (7) ((7L) C7-13) (7R) (7r)) extending
in the direction of extension of the cantilever (2), viewed from the front J: D Located on each side
of the square, and arranged so that the paired sides are parallel to each other, the legs above the
respective pole piece portions (7L) C7, e) (71%) (7r) (8) ((8L) (8A) (8R) (8r)) is extended, and the
upper end of each of the leg portions (8) is magnetically coupled by the short core portion (9). In
addition, on each leg (8 L) C 813) (8 R) (8 r): l17-yl (10) ((IOL) Doz) (1 oa) (10 r) is wound, and
the coils (10 L) and (10 L) , A) ,! In this case, for example, the left signal is reproduced, and the
coils (IOR) and (10r) are connected in series so that the right signal is reproduced. In practice, as
shown in FIG. 3, the short core portion (9) and the sub-leg portion (El ((12L) (1u) (12R)) which is
bent downward from the end portion as shown in FIG. x2 r)), and after the carp h (IOL) (1 o, a)
(IOR) (1 or) is attached to each leg (8 L) (u) (8 R) (8 r), this short core ( 9) each sub-leg (12L) (12g) (12B) (12r) is further inserted into = (I (IOL) (10, 6) (IOR) (10r) and leg (8L) (U) (8R) (8r)
magnetically coupled.
In general, each part constituting such a magnetic circuit (6) has a pole piece (a force and a leg
(8) are continuously and integrally formed, and the short core (9) is a top plate as described
above. The part Uυ and the sub-leg (121 are integrally formed, and further, these are made of
permalloy. This is noted because permalloy has a large Bs and μ as described above. However,
looking at the characteristics of the MM cartridge using this permalloy in practice, satisfactory
characteristics can not always be obtained. That is, as shown by c and d of the μ-frequency
characteristic curve in FIG. 4, there is a disadvantage that the μ is greatly reduced at high
frequencies, and it is difficult to further stack and bond permalloy. That is, in order to improve
the μ-frequency characteristics, a thin permalloy plate may be made and then laminated, but in
this case bending, processing, lamination, bonding and then annealing must be performed, and
the high temperature (at this time) This laminated permalloy is practically impossible because
there is no adhesive that withstands 1100 ° C. to 1200 ° C.). Therefore, improvement of the
μ-frequency characteristic by lamination can not be expected. FIG. 5 shows the frequency
characteristics of a cartridge using permalloy. This figure is based on the assumption that the
level at the time of reproduction of the 1 kHz signal is O dB, and as is apparent from this, the
frequency characteristics in the high region are degraded. It is believed that permalloy is
generally good for use in magnetic circuits with large Bs and μ, but it is believed that these
constants will be small during the manufacturing process. That is, in order to construct the
above-mentioned magnetic circuit with permalloy, permalloy material is punched into a
predetermined mold, and the necessary part is bent and this is annealed as is apparent from
FIGS. 2 and 3. Although not shown, the pole piece portion (7) is molded with a molding material
such as resin, and the coil (11 is attached to the leg portion (8) respectively, and then the upper
portion of the short core portion (9) The magnetic circuit is configured by inserting one (one).
Therefore, at the time of manufacture Nopole piece, forming a short core Sul-Harmalloy bending,
impact or vibration or pole piece part (Shrink strain of resin at molding by resin of force, coil of
short core part 9 (10) (actually coil bobbin 2.) EndPage: 2 due to stress and the like to the short
core portion at the time of press-fitting into the inside, which is considered to deteriorate the
chassis characteristics. Table 1 below shows the changes in Bs, He, B7Bs and .mu. Before and
after impact of Permalloy with respect to the frequencies of Bs except IKHz, 3 KHz, 10 KHz and
30 KHz.
However, measurement of μ after impact was omitted because it is well known that this
extremely degrades. As is clear from this table, permalloy becomes smaller in Bs and B2S3 after
impact and Hc becomes a dog. Therefore, as shown in FIGS. 2 and 3, it is considered that the
characteristics are degraded by bending the permalloy or applying an impact to the permalloy at
the time of the bending. In the present invention, at least one part of the magnetic circuit (6) of
the cartridge described above is constituted of an amorphous soft magnetic metal ribbon, that is,
a non-magnetostrictive amorphous soft magnetic metal body. . Therefore, in the magnetic circuit
(6) shown in FIG. 2 and FIG. 3, the pole piece portion (7) and the leg portion (8) continuous
thereto are formed of amorphous metal or the short core portion (9) Is formed of an amorphous
metal, or all of the metals constituting the magnetic circuit (6) are formed of an amorphous
metal. Since this amorphous metal is well known in the prior art, its detailed description will be
omitted, but as shown by curve a in FIG. 4, the .mu.-frequency characteristics are extremely good
6D and the resistivity is about 140 to 200 .mu..OMEGA. The eddy current loss is also reduced by
a factor of several. r Next, when this amorphous metal Bs, Hc and / Bs are compared with
permalloy (after annealing), they are as shown in Table 2 below. Table 2 Such an amorphous
metal has a thickness of about 50 μm or less because of its manufacturing condition, and it is
difficult at present to make one having a thicker thickness than this. Therefore, in order to obtain
the necessary cross sectional area of the magnetic path, lamination is performed. In addition,
there is a risk of crystallization when the pole piece portion (the force is absorbed by the resin).
That is, since the resin mold takes a few seconds at about 200 ° C., the amorphous metal may
be crystallized at this time. In such a case, the short core portion (9) of the magnetic circuit (6)
Only the amorphous metal mentioned above may be formed. As shown in FIG. 6A or 6B, when
the sub-legs (12L), (12A), (12B) and (12r) are bent in this stacked state when the short core
portions (9) are stacked and configured. The laminated part peels off. Therefore, in this case, the
respective amorphous metal thin ribbons constituting the short core portion (9) are individually
bent in advance into a predetermined shape, and are post-laminated. FIGS. 7 and 8 show an
example of a jig for forming the short core portion (9). That is, as shown in FIG. 9B, the thin strip
(2) made of amorphous metal punched into the shape as shown in FIG. 9A has its projections
(14a) and (14b) in advance with respect to the main plate portion α. Are folded at right angles to
form a plurality of short core blanks ae, which are alternately polymerized and bonded together
as shown in FIG. 9C to form an inner short core portion (17).
In this case, the jig (181 shown in FIG. 7 is used). This jig (to) is formed of an outer frame α0
and a pair of inner frames (20a, 20b) whose cross sections are formed in a square shape, and on
the inner surface of the outer frame cl 3 EndPage: 3 respectively Concave grooves (21a) and
(21b) are formed in pairs, and in the inner frames (20a) and (20b), convex streaks (22a and 21b)
are respectively opposed to the concave grooves (21a) and (21b). (22b) is formed. The distance
between the bottom surfaces of the opposing grooves (21a) and (21b) is selected as DI.
Therefore, with respect to the jig (] 8) shown in FIG. 7, the short core material plate (10 with its
projections (14a) and (14b) shown in FIG. 9B is inserted into the grooves (21a) and (21b). The
plurality of projections (14a) and (14b) are moved by moving the inner frames (20a) and (20b)
so that they are separated from each other when the required number of sheets are stacked. It is
possible to bond between the outer frame (L'11 and the inner frames (20a, 20b). In this state, a
plurality of material plates (1e) are adhered to each other not only at the main plate portion (15)
but also at the protrusions (14a) and (14b). Thus, the inner short core portion αη shown in FIG.
9C is formed. At this time, the distance between the outer surfaces of the projections (14a) and
(14b) is selected to be the above-mentioned distance D1. FIG. 9C shows the case where four
material plates (16) are laminated, but the invention is not limited thereto. This inner short core
portion (17) is shown as one layer in FIG. In the present embodiment (d, the outer short core
portion (c) is further laminated on the outer side of the inner short core portion α 形成 to form
the intended short core portion (9), as shown in FIG. As is apparent, the leg portion (8) of the
pole piece portion (7) is bonded between the inner and outer short core portions (11) and the
t23 + projections (14a) and (14b), thereby The magnetic connection is ensured. The outer short
core portion (c) can also be formed by laminating in the same manner as the inner short core
portion α, that is, as shown in FIG. 9C. However, the distance between the inner surfaces of the
protrusions (14a) and (14b) is selected to be D2 in this case. Accordingly, (D2−D1) / 2 becomes
the thickness of the core of the pole piece portion (the leg portion (8) of force). FIG. 8 shows a jig
for forming the outer short core portion (231, and is formed of an inner frame (2.fwdarw. And a
pair of outer frames (25a) and (25b)).
A pair of concave grooves (26a) and (26b) are formed on the left and right walls of the inner
frame C24), and a pair is formed on the inner surfaces of the outer frames (25a) and (25b) facing
them. The ridges (27a) and (27b) are formed, and the distance between the bottoms of the
recessed grooves (26a) and (26b) is selected as D2 described above. Therefore, as in the case of
forming the inner short core portion (I7), the projections (14a) and (14b) are alternately
provided with the plurality of core materials (t6) shown in FIG. The core materials laminated
together are adhered in a state where the outer frames (25a) and (25b) are tightened toward the
inside of the outer frame in a state where the predetermined number of sheets are stacked. As a
result, it is possible to obtain an outer short core portion (c) in which the distance between the
inner surfaces of the protrusion portions (14a) and (14b) is D2. In this way, it is possible to form
the intended short core portion (9), and the projections (14a) and (14b) stacked on one another
are respectively the auxiliary legs (12L), 12A, 12R, and 12r. Form the Although the above
describes the case where the short core portion (9) is formed, the pole piece portion (force and
leg portion (8) are combined in a series, ie, integrated to form a plurality of amorphous soft
magnetic metal ribbons as described above) Can be formed by stacking (131A). Next, the results
of measurement of Bs, Hc, BT / B5 and μ before impact and after impact on amorphous metal
are shown in Table 3. Table 3 EndPage: 4 As apparent from this table, as for the amorphous
metal, no significant change is seen as in the case of the permalloy metal shown in Table 1 before
and after the impact, and hence There is almost no problem in bending the metal strip. FIG. 11
shows the μ-frequency characteristics of permalloy and amorphous metal before and after
molding, in which curve P shows permalloy, A shows amorphous, suffix a shows before molding,
b shows the mold Indicates the later. As apparent from this curve, it can be seen that the
properties of amorphous metal are superior to that of permalloy even after molding. As the
ashurus metal, it is possible to use an alloy composed of Fe, Co, 8i and B at a weight percent of
4.7.7 o, 3.15 and 10, respectively. As described above, according to the present invention, since it
is used as a magnetic circuit of an amorphous soft magnetic metal ribbon cartridge having a
small magnetostriction constant mainly composed of Fe and Co, it has the following features.
That is, the cartridge inherently picks up the mechanical vibration and converts it into an
electrical signal, so that the magnetic circuit is always exposed to the vibration during its use.
However, as described above, according to the present invention, since the change in the
magnetic characteristics due to shock and vibration is extremely small, the level change due to
the vibration of the turntable and the arm is also extremely small, and thus the cartridge having a
very good feeling of sound. It has features that can be manufactured. In addition, since the
squareness ratio and the coercivity are small, the saturation magnetization and the magnetic
permeability are large, a cartridge having a large dynamic range and good linearity can be
obtained. When the short core portion (9) is manufactured as shown in FIG. 9C, the core material
OQ shown in FIG. 9B regardless of the inner short core portion (17) and the outer short core
portion (iii). By preparing a plurality of sheets in advance, it is possible to easily manufacture the
outer short core portions (two additional and inner short core portions a 異 な る having
different sizes). Although the MM type cartridge is described above, it will be apparent that the
magnetic circuit of the moving coil type or MC type cartridge can be made of amorphous metal
as well.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an example of a
conventional cartridge, FIG. 2 is a perspective view of a part thereof, FIG. 3 is a perspective view
of a short core, and FIG. Fig. 5 is an output-frequency characteristic curve diagram, Figs. 6A and
6B are side views showing the state of the laminated core, and Figs. 7 and 8 are perspective
views showing a jig, respectively. B and C are perspective views showing the manufacturing
process of the short core, FIG. 10 is a side line portion showing its assembled state, (8) is a leg
portion, and (9) is a short core portion. EndPage: 5 JP 55-68799 (6) EndPage: 6X [【【5 I /)】 ゝ
End EndPage: 7