JPH0383212A - Magnetic head - Google Patents

Abstract

PURPOSE:To produce a magnetic head for a floppy disk drive at low cost by constituting a head core of metal magnetic material which has mass productivity and can be processed by punching and etching, and constituting the housing which presents a sliding surface to a recording material and holds the core by using a resin mold which can be precisely molded. CONSTITUTION:The first head core 1 for recording and reproducing consists of five-layered 25-mum thick high hardness permalloy, while the second head core 2 for recording and reproducing consists of a seven-layered body of the same material. Since the width for recording/reproducing is determined by the width of the core 1, the core 2 is made larger to negrect an assembling error for core layers and to omit a process for fine adjustment. A core 3 for erasing produced by punching and bending a 50mum thick high hardness permalloy is disposed on both sides of the core 1 with nonmagnetic metal thin plates 4 interposed to form a gap A for erasing and to determine the width for erasing. Cores 1, 2 are mounted on the first and second housing 5, 6, respectively, which consists of thermoplastic resin containing carbon fiber by 30wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic head for a floppy disk drive (hereinafter referred to as FDD) used as a storage device for personal computers, word processors, and the like.

Conventional technology FDDs have traditionally been used for recording and reproducing large amounts of information in technical fields where reliability is important, such as office computers, personal computers (hereinafter referred to as personal computers), and word processors (hereinafter referred to as word processors). However, in recent years, it has also begun to be used in portable word processors, video game machines, hobby computers, etc. In general, this type of equipment is required to be low-priced, and the FDDs used must also be low-priced.Therefore, it is desirable to provide magnetic heads, which account for a high price weight among FDDs, at a low price. has been done.

Figures 3 and 4 show a conventional magnetic head used in an FDD, with Figure 3 being an external perspective view and Figure 4 being a schematic plan view showing the vicinity of the core gap of the magnetic head. . In FIGS. 3 and 4, reference numeral 21 denotes a magnetic helad core, which is composed of a recording/reproducing core 23 having a recording/reproducing gap 22 and an erasing core 25 having an erasing gap 24. In FIG.

In addition, each core 23.25 has ferrite (the shaded area in Figure 4) and barium titanate (the area other than the ferrite).
It is composed of. Note that 26 is a traveling guide made of a ceramic material such as barium titanate, which is disposed on both sides of the magnetic helad core 21, and 27 and 28 are recording/reproducing and erasing coils provided in the magnetic helad core 21.

When recording is performed using the magnetic head configured in this manner, at the same time as the recording is performed by the recording/reproducing core 23, both sides of the recording width are erased by the pair of erasing gaps 24, creating a no-signal area, which prevents malfunctions due to misalignment of the head position. be done. On the other hand, although not shown, in general, magnetic heads for audio use, for example, metal-based magnetic materials such as permalloy are used as the head core material, and the magnetic heads are formed by processing methods that are suitable for mass production, such as punching or etching. There is. In addition, recently, there have been developed products that use a resin member on the sliding surface with the recording medium (Japanese Patent Application Laid-Open No. 61-15
No. 0114) or one using permalloy as the material for the head core (Japanese Patent Application Laid-open No. 153810/1983) has been proposed.

Problems to be Solved by the Invention In the conventional magnetic head for FDD, the magnetic head member is made of ceramic materials such as ferrite and barium titanate as mentioned above, and therefore requires several precision machining processes such as cutting, grinding, and polishing. Ten steps are required and the price is inevitably high.
It has been difficult to provide a low-cost FDD magnetic head that meets the above requirements.

In addition, regarding the other two sides, the former has a herad core member made of conventional ferrite, and the cost effect is small.
In the latter case, the housing material is made of low-temperature firing ceramic, so there are some drawbacks in terms of dimensional accuracy, and the dimensional W! There were problems such as the need for 1m clearance.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a magnetic head that can solve the above-mentioned problems regarding cost reduction of magnetic heads for PDD.

Means for Solving the Problems In order to solve the above problems, the magnetic head of the present invention includes erasing cores made of a metal magnetic material arranged on both sides of a first recording/reproducing core made of a metal magnetic material. , inserting this first recording/reproducing core into a first housing made of a resin molded product, inserting a second recording/reproducing core made of a gold magnetic material into a second housing made of a resin molded product, These two housings are fixed to each other such that one ends of the recording/reproducing core are connected to each other by inserting the recording/reproducing coil.

In addition, in the above configuration, the resin molded product that is the housing is heated! It has a coefficient of 1 or more that is smaller than that of the metal magnetic material constituting the recording/reproducing and erasing cores, and contains an inorganic material.

Further, in the above configuration, the width of the second recording/reproducing core is made wider than the width of the first recording/reproducing core.

Furthermore, in the above structure, a nonmagnetic metal thin plate is inserted between the first recording/reproducing core and the erasing core to form an erasing gap.

Effects According to the above structure, the head core, which is the main magnetic head member, is made of a metal magnetic material that can be punched and etched for mass production, and also serves as a sliding surface for contacting the recording medium and holds the head core. Since the housing is made of a resin molded product that can be precisely molded, the price can be reduced.

In addition, by using a material with a coefficient of thermal expansion smaller than that of metal magnetic materials as the material for the resin molded product, it is possible to prevent the helad core from popping out at low temperatures, which can cause damage to the recording medium, and from sliding contact with the recording medium at high temperatures. Deterioration of characteristics due to deformation of the surface and depression of the head core can be prevented.

Further, by incorporating an inorganic material into the resin constituting the housing, it is possible to prevent wear of the sliding surfaces and to improve the workability of the resin itself, that is, to prevent the occurrence of flakes.

Furthermore, by configuring the width of the second recording/reproducing core to be wider than the width of the first recording/reproducing core, it is possible to absorb mutual misalignment that occurs during assembly, thus ensuring dimensional accuracy due to resin molding. Coupled with this, the fine adjustment process can be eliminated from the assembly process.

Furthermore, a non-magnetic metal thin plate was inserted between the first recording/reproducing core and the erasing core to form an erasing gap.
By changing the thickness of this thin metal plate, the width of the erasing gear can be easily set.

EXAMPLE An example of the present invention will be described below with reference to FIGS. 1 and 2.

In FIGS. 1 and 2, reference numeral 1 denotes a first recording/reproducing head core (hereinafter referred to as the first head core), which is formed by laminating five 25 μm high hardness permalloy (metallic magnetic material). Reference numeral 2 denotes a second recording/reproducing herad core (hereinafter referred to as a second herad core), which is similarly formed by laminating seven sheets. The recording/reproduction width is determined by the width of the first head core 1. Therefore, by making the second head core 2 larger (by the size of two cores), it is possible to absorb the assembly error of one core. becomes unnecessary. On both sides of the first head core 1, erasing cores 3 formed by punching and bending 50μ high hardness permalloy through a non-magnetic metal thin plate 4 are arranged, and an erasing gap A is formed and the erasing width is Settings are made.

First and second herad cores 1 configured as above
. Both the housings 5 and 6 are joined and fixed to each other with a pair of pressing springs 9 and 10 so that they are inserted through each other, and then the erasing back core 11 forming the erasing coil is inserted, and then a layer of epoxy, etc. A magnetic head is formed by injecting molding resin.

The material of each housing 5.6 used here has a coefficient of thermal expansion smaller than that of metal magnetic materials, and carbon fiber (
Inorganic equipment 1! l) is a thermoplastic resin containing 30% by weight.Although thermoplastic resin was selected from the viewpoint of price, thermosetting resin may be used as long as it satisfies the condition of thermal expansion coefficient. If it is made larger than the material, the core may protrude at low temperatures, damaging the recording medium or causing characteristic deterioration at high temperatures.It is also necessary to make the coefficient of thermal expansion of the molding resin close to that of the metal magnetic material. However, it is necessary to add a large amount of filler such as carbon fiber carbonate whiskers, which impairs the workability of the injection process.

Therefore, at least the coefficient of thermal expansion of the housing material needs to be smaller than that of the metal magnetic material.

Further, in order to improve the wear resistance of the magnetic head, it is necessary to include carbon fiber. However, in order to improve wear resistance and workability (occurrence of cracks on the 111 plane), it is better to fill the carbon fiber with a larger amount, but the limit is about 50%.

If it is less than 30%, the occurrence of cracks due to processing is noticeable and post-processing is required. However, resin filled with 30% carbon fiber had good moldability and almost no wear was observed even after 30 million passes. . In addition, almost no damage to the media was observed.

Effects of the Invention As described above, according to the structure of the present invention, a magnetic head conventionally made by precision machining of ceramic materials can be
As the head core material, we use a metal magnetic material that can be punched and etched for mass production, and as the housing material that holds the head core and serves as the Wii contact surface with the recording medium, we use a resin molded product that can be precisely molded. Therefore, manufacturing costs can be reduced.

In addition, as a resin material, the thermal B tensile coefficient is smaller than that of metal magnetic materials! ! ! By using a material containing mechanical materials, characteristics under various environments can be ensured, excellent wear resistance can be obtained, and a sufficient head life can therefore be ensured. Moreover, by making the width of the second recording and reproducing core wider than the width of the first recording and reproducing core among the first recording and reproducing core and the second recording and reproducing core that constitute the head core, It is possible to absorb misalignment when the image recording/reproducing core is joined, and therefore, the step of @adjustment can be made unnecessary, so that manufacturing costs can be reduced. Furthermore, since an erase gap is formed by inserting a non-magnetic thin metal plate between the first recording/reproducing core and the erase core, the width of the erase gap can be easily set by changing the thickness of this thin metal plate. can do.

[Brief explanation of drawings]

1 and 2 show an embodiment of the present invention,
Fig. 1 is an exploded perspective view of the magnetic head, Fig. 2 is an enlarged plan view of the core gap portion, Figs. 3 and 4 show conventional examples, and Fig. 3 is a general Q perspective view of the magnetic head. FIG. 4 is an enlarged plan view of the core gap portion. DESCRIPTION OF SYMBOLS 1... First recording/reproducing head core, 2... Second recording/reproducing head core, 3... Erasing core, 5...
First housing, 6... second housing.

Claims (1)

[Claims] 1. An erasing core made of a metal magnetic material is arranged on both sides of a first recording/reproducing core made of a metal magnetic material, and this first recording/reproducing core is made of a resin molded product. A second recording/reproducing core made of a metal magnetic material is inserted into a second housing made of a resin molded product, and both housings are connected so that one end of the recording/reproducing core is mutually connected. Magnetic heads that are fixed to each other so that recording and reproducing coils are inserted and joined together. 2. The resin molded product as the housing has a coefficient of thermal expansion smaller than that of the metal magnetic material constituting the recording/reproducing and erasing cores, and contains an inorganic material. magnetic head. 3. The magnetic head according to claim 1 or 2, wherein the width of the second recording/reproducing core is wider than the width of the first recording/reproducing core. 4. The magnetic head according to claim 1, wherein a non-magnetic metal thin plate is inserted between the first recording/reproducing core and the erasing core to form an erasing gap.