JPH0643805U - Magnetic head - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a high-performance magnetic head which is simple in process, jig and tool, and capable of cost reduction by improving a holding member for holding a core and the like. [Structure] A front core 1 slidingly contacting a magnetic recording medium and a back core 2 at a rear part thereof are separately configured, and a magnetic core formed by joining the front core 1 and the back core 2 together with the magnetic core is held. The holding member 5 is made possible and a case 6 for housing the magnetic core and the holding member is provided, and the holding member 5 is configured such that one end of the holding member 5 projects from the case 6.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a magnetic head for slidingly contacting a magnetic core with a magnetic recording medium such as a magnetic card or a magnetic tape to magnetically record and reproduce information, and more particularly to the structure thereof.

[0002]

[Prior art]

 As an example of a conventional magnetic head, in a magnetic core, a front part that is in sliding contact with a magnetic recording medium and a rear part on the opposite side are formed as a separate body of a front core and a back core, and are joined together to form a crevite type. Some have adopted a so-called structure. According to this structure, it is possible to manufacture the front core and the back core with suitable magnetic materials. Normally, the front core uses sendust alloy or ferrite in consideration of wear resistance, and the back core In many cases, a permalloy laminated structure is used in consideration of cost and magnetic characteristics. A holding member is used to hold these cores in the case.

[0003]

[Problems that the device is trying to solve]

 However, in the structure of the magnetic head adopting the crevite-type magnetic core as described above, when manufacturing the back core, the laminated structure is adopted, and therefore it is often necessary to obtain the necessary thickness (track width). It is necessary to stack the individual cores. Therefore, an adhesive is applied between the single core and the single core, and positioning is performed so that the single core and the single core do not shift, and the high temperature and high pressure state required to cure the adhesive are obtained. Jigs and tools for this are required.

Further, in order to obtain magnetic characteristics, the joining portion with the front core portion has to be smoothly finished, and thus has a clevite structure aimed at low cost. However, the process, jigs and equipment required for stacking will inevitably cost much, and further cost reduction is difficult.

Further, in many cases, conventional holding members merely hold the core and the like in the case.

In view of the above problems, the present invention provides a high-performance magnetic head which has an improved holding member for holding a core and the like, which has simple steps, jigs and tools, and which enables cost reduction. The purpose is to

[0007]

[Means for Solving the Problems]

 In order to solve the conventional problems and achieve the above-mentioned object, the magnetic head according to the present invention comprises a front core that is in sliding contact with a magnetic recording medium and a back core at the rear of the magnetic head separately. A magnetic core formed by joining a magnetic core and a back core; a holding member capable of holding the magnetic core; and a case for housing the magnetic core and the holding member. It is configured to project from the case.

In addition, a front core that is in sliding contact with the magnetic recording medium and a back core at the rear part are separately configured, and the magnetic core is formed by joining the front core and the back core, and the magnetic core can be held. And a holding member, the holding member having a supporting portion capable of supporting the back core.

Further, a front core that is in sliding contact with the magnetic recording medium, a back core that is arranged at a rear portion of the front core, a bobbin around which a coil wire is wound and the back core is inserted, and at least the bobbin are provided. A holding member capable of holding the bobbin is provided, and the holding member is configured to have a positioning portion that positions the bobbin.

[0010]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing a first embodiment of the present invention. In FIG. 1, 1 is a front core and 2 is a back core. The back core 2 is formed into a U shape by bending a plate-shaped magnetic material. The rounded portion 2a formed by this bending process is formed in a substantially semicircular shape. The tip 2b of the back core 2 is located inward of the head 10 with respect to the tip 1a of the front core 1. Therefore, when the front core 1 is processed, the back core 2 is not processed, and the joint area between the front core 1 and the back core 2 is kept constant. A coil wire 3 is wound around the bobbin 7. Reference numeral 4 denotes a terminal, which is fixed to the bobbin 7 and connected to the coil wire 3. A core support 5 supports and fixes the back core 2 combined with the bobbin 7. Reference numeral 6 is a shield case, and 8 is a screw. By applying a pressing force, the front core 1 and the back core 2 are joined together, and the shield case 6 is grounded.

In this embodiment, the front core 1 is made of sendust alloy, and its characteristics are as follows. Maximum saturation magnetic flux density: 8650 [G], initial permeability: 40,000, coercive force: 0.032 [O _e ], volume resistivity: 105 [μΩ · cm], linear expansion coefficient: 1.3 × 10 ^{− 5} [/ ° C]. The back core 2 and the shield case 6 are made of permalloy, and their characteristics are as follows. Maximum saturation magnetic flux density: 7500 [G] or more, initial magnetic permeability: 30,000 or more, coercive force: 0.017 [O _e ] or less, volume resistivity: 55 to 65 [μΩ · cm], linear expansion coefficient: 1.2 × 10 ^-5 [/ ° C]. On the other hand, the core support 5 is made of PPS (polyphenylene sulfide) resin, and its characteristics are as follows: thermal deformation temperature: 260 [° C] or higher, linear expansion coefficient: 2.2 x 10 ^-5 [/ ° C], volume Specific resistance: 10 ¹⁶ [Ω · cm].

Next, a method of manufacturing the magnetic head 10 will be described with reference to FIG. In addition, in order to make it easier to understand the correlation of the components in each process, the illustration of each process is shown along with the predetermined direction, but in reality it is in the proper direction considering accuracy and workability. It is directed and work is being done.

<Step 1> As shown in FIG. 2A, the plate-shaped back core 2 is formed into a U-shape by bending.

<Step 2> Next, as shown in FIG. 2B, the back core 2 is passed through the opening 7 a of the bobbin 7 around which the coil wire 3 is wound so that the back core 2 and the bobbin 7 are wound together. Combine with 7.

<Step 3> As shown in FIG. 2 (c), the first contact portion 5 a of the core support 5 is brought into contact with the contact portion 7 b of the bobbin 7 for positioning, and the back core 2 is incorporated. The bobbin 7 that has been removed is temporarily fixed to the core support 5.

<Step 4> As shown in FIG. 2D, the core support 5 to which the back core 2 and the bobbin 7 are temporarily fixed is housed in the shield case 6 and fixed in the shield case 6 with the screw 8. This fixing is performed by bringing the end portion 6a of the shield case 6 into contact with the second contact portion 5b of the core support 5 and pressing the back core 2 with the screw 8 screwed into the shield case 6. .

<Step 5> As shown in FIG. 3 (e), the front core 1 to which the two cores are joined is brought into contact with the core support 5 for positioning, and the screw 8 is moved from the state of step 4. By further screwing in, the front core 1 and the back core 1 are joined. In this state, a resin is embedded in the shield case 6 and the resin is further cured to fix the member housed in the shield case 6. In this embodiment, a thermosetting epoxy resin is used for this resin.

<Step 6> As shown in FIG. 3F, the portion of the screw 8 protruding from the shield case 6 is removed.

<Step 7> As shown in FIG. 3G, the tip of the front core 1 is ground or polished so that a predetermined gap depth can be obtained.

Through the above steps, the magnetic head according to the present invention can be obtained.

Next, the core support will be described with reference to FIGS. 4 to 13.

FIG. 4 is a perspective view showing an embodiment of the core support. As described above, the first contact portion 5a and the second contact portion 5b of the core support 5 are positioned so that the contact portion 7b of the bobbin 7 and the end portion 6a of the shield case 6 are in contact with each other. A third contact portion 5c supports the end portion of the back core 2 and contacts the front core 1 to position the track. Reference numeral 5d denotes a fourth contact portion, which is in contact with the bottom portion of the front core 1 to accurately set the gap depth. A guide portion 5e serves as a positioning guide for the back core 2. 5f is a fifth contact portion, and one end of the bobbin 7 is in contact therewith. 5g is an insertion port into which one end of the back core 2 is inserted. Then, both ends of the back core 2 are supported so as to sandwich the support portion 5h. In this core support 5, the first contact portion 5a, the second contact portion 5b, and the fourth contact portion 5d are set on the basis of the reference surface 5A, so that they are brought into contact with the respective contact portions. The members are kept in a highly precise positional relationship with each other. Moreover, since the front core 2 abutted against the fourth abutting portion 5d is processed with the reference surface 5A as a reference, the processed gap depth can be obtained with high accuracy.

Next, another embodiment of the core support will be described with reference to the drawings. 5 to 8 show an embodiment in which a convex portion is provided at a predetermined position of the core support to apply a pressing force to the back core 2 or the front core 1 so that the core can be held by the core support. . In the core support 21 of the embodiment shown in FIG. 5, two convex portions 21b are formed in the lower portion in the drawing of the back core insertion opening 21a, so that the back core 2 can be held. Although the convex portion 21b is formed in the lower portion of the insertion opening 21a in this embodiment, it may be formed in the upper portion of the insertion opening 21a. The core support 22 of the embodiment shown in FIG. 6 is provided with a projecting support portion 22a on the core support 5 shown in FIG. 4, and two projecting portions 22b are formed on the side surfaces of the projecting support portion 22a. Also in this embodiment, the back core 2 can be held. The core support 23 of the embodiment shown in FIG. 7 is provided with a projecting support portion 23a so as to project from the contact surface of the front core 1, and two projecting portions 22b are formed on the inner side surface of the projecting support portion 23a. Therefore, the front core 1 can be held. In this embodiment, since the front core 1 is pressed against the positioning portion 23c, the front core 1 can be positioned with high precision (track positioning). In the core support 24 of the embodiment shown in FIG. 8A, a projecting support portion 24a is provided on the upper portion of the core support 24 in the figure, and projecting portions 24b and 24c are formed on both upper and lower sides of the projecting support portion 24a. There is. Further, in this embodiment, two back core insertion openings 24d and 24e are formed. Then, as shown in FIG. 8B, when the core support 24 incorporating the back core 2 is inserted into the shield case 6, the case 6 presses the convex portion 24b and the convex portion 24c. The pressure is transmitted to the back core 2, the back core 2 is held, and the front core 1 and the back core 2 can be reliably joined. Therefore, the screw 8 in the embodiment shown in FIG. 1 can be omitted. In this embodiment, the convex portion 24b is formed in a semi-cylindrical shape, but it may be formed in a semi-spherical shape and provided at the tip of the protruding support portion 24a.

The core support shown in FIGS. 9 to 12 has more positioning portions than the core support shown in FIG. The core support 25 shown in FIG. 9 is provided with positioning portions 25a and 25b so as to sandwich the front core 1. With this configuration, the front core 1 is positioned. In the core support 26 shown in FIG. 10, the shape of the insertion opening 26a of the back core 2 is trapezoidal. With such a shape, the hypotenuse portion of the insertion opening 26a engages with the back core 2, so that the back core 2 is held and fixed to the core support 26. The core supports 27 and 28 shown in FIGS. 11 and 12 both have a positioning portion that positions and holds the bobbin 7. The core support 27 shown in FIG. 11 positions and holds the bobbin 7 such that the positioning portions 27a and 27b sandwich one end of the bobbin 7. The core support 28 shown in FIG. 12 has positioning portions 28a and 28b formed of grooves, and one side of both ends of the bobbin 7 is fitted into the positioning portions 28a and 28b to maintain the positioning.

In the core support 28 shown in FIG. 13, one side surface of the insertion port 29 a of the back core 2 is opened. Therefore, the back core 2 can be inserted in the direction of the arrow A, which facilitates the assembly. Further, since the back core 2 is inserted from the direction of arrow A, the guide protrusion 29b is provided only on one side. The guide protrusion 29b serves as an abutting portion in the side surface direction of the back core 2.

FIG. 14 is a sectional view showing a second embodiment of the magnetic head according to the present invention. In this embodiment, the screw 8 used in the first embodiment is replaced by an elastic member 9 made of a conductive leaf spring. The elastic member 9 presses the back core 2 with its own elastic force, thereby joining with the front core 1. Further, the back core 2 and the shield case 6 are grounded.

The front core 1, the back core 2, and the shield case 6 may be made of other magnetic metal, such as ferrite, as long as the functions described above are fulfilled. Further, the core support 5 may also be another member such as an aluminum die cast member or a brass press member as long as it is a non-magnetic material and can hold the core. By using a conductive member for the core support 5, a member for grounding (for example, the screw 8) becomes unnecessary. In this case, the back core 2 may be fixed to the core support 5 with a conductive adhesive in order to positively connect the core support 5 and the back core 2 to each other.

[0029]

[Effect of device]

 As is apparent from the above description, in the magnetic head according to the present invention, the holding member capable of holding the magnetic core formed by joining the front core and the back core has an end portion that houses the magnetic core and the holding member. Since it is configured to project from the case, it is possible to machine the end of the front core with the projecting end as a reference, and it is possible to obtain an accurate gap depth.

Further, since the holding member has the supporting portion capable of supporting the back core, positioning of the back core is facilitated and assembly is facilitated.

Further, since the holding member that can hold the bobbin bobbin into which the back core is inserted has the positioning portion that positions the bobbin, the positioning of the back core can be facilitated with the same configuration as described above. It also facilitates assembly.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a process drawing of the magnetic head shown in FIG. 1, showing steps (a) to (d) of the whole steps shown in FIG.

FIG. 3 is a process drawing of the magnetic head shown in FIG. 1, showing steps (e) to (g) of the overall steps shown together with FIG.

FIG. 4 is a perspective view showing an embodiment of a core support.

FIG. 5 is a perspective view showing another embodiment of the core support.

FIG. 6 is a perspective view showing another embodiment of the core support.

FIG. 7 is a perspective view showing still another embodiment of the core support.

FIG. 8 is a perspective view showing still another embodiment of the core support.

FIG. 9 is a perspective view showing still another embodiment of the core support.

FIG. 10 is a perspective view showing still another embodiment of the core support.

FIG. 11 is a perspective view showing still another embodiment of the core support.

FIG. 12 is a perspective view showing still another embodiment of the core support.

FIG. 13 is a perspective view showing still another embodiment of the core support.

FIG. 14 is a cross-sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 1 front core 2 back core 3 coil wire 5 core support 6 shield case 7 bobbin 8 screw 9 elastic member 10 magnetic head

Claims (8)

[Scope of utility model registration request] 1. A magnetic core formed by separately forming a front core slidingly contacting a magnetic recording medium and a back core at a rear portion thereof, and joining the front core and the back core, and holding the magnetic core. And a case for accommodating the magnetic core and the holding member, wherein one end of the holding member projects from the case. 2. The magnetic head according to claim 1, wherein the holding member has a support portion that supports the back core at the other end portion. 3. The magnetic head according to claim 2, wherein the support portion can further support a front core. 4. The magnetic head according to claim 2, wherein the support portion further has a track positioning portion. 5. A magnetic core comprising a front core slidingly contacting a magnetic recording medium and a back core behind the magnetic core, the magnetic core comprising the front core and the back core joined together, and the magnetic core can be held. And a holding member for holding the back core, the holding member having a supporting portion capable of supporting the back core. 6. The magnetic head according to claim 5, wherein the supporting portion is provided with a convex portion capable of pressing and holding the back core. 7. A magnetic head according to claim 5, wherein the holding member is formed of a conductive member. 8. A front core slidably contacting a magnetic recording medium, a back core arranged at a rear portion of the front core, a bobbin around which a coil wire is wound and into which the back core is inserted, and at least the bobbin. And a holding member capable of holding the holding member, wherein the holding member has a positioning portion that positions the bobbin.