JP3272103B2 - Slider structure of composite magnetic head and mold structure for molding this slider structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite magnetic head, and more particularly to a slider structure of a magnetic head in which recording / reproducing and erasing heads used in a floppy disk drive and the like are combined, and a mold structure for molding the slider structure. It is.

[0002]

2. Description of the Related Art In order to perform recording and reproduction on a magnetic recording medium, for example, a floppy disk, a composite magnetic head in which a recording head and an erasing head are combined is used. Magnetic heads are also required to have a small and precise structure.

A magnetic head generally known as a bulk type head includes a ceramic slider which is in sliding contact with a recording surface of a magnetic recording medium and a gimbal spring which supports the slider on a carriage arm. A magnetic core for forming a gap, a read / write coil assembly and an erase coil assembly attached to the magnetic core, and a back core for magnetically closing an open end of the magnetic core are incorporated.

As shown in FIG. 9, such a slider structure has an escape reference surface 41 on the sliding contact side of the blank 40.
A more protruding main sliding contact surface portion 42 and an auxiliary sliding contact surface portion 43 are formed. Both of the sliding contact surface portions 42 and 43 have an elongated half-moon shape whose outer side is curved. Main slide contact surface 42
A core slit 44 formed in the blank 40 is opened in the center of the blank.

The magnetic core, that is, the core chip 4
5 (see FIG. 12) was fixed to the core slit 44 by dropping a bar-shaped sealing glass 46 into the core slit 44 and heating and melting it as is well known. However, when the sealing glass 46 is melted, the sealing glass 46 shrinks toward the center, so that the glass is insufficiently filled near the end of the core slit 44.

In order to solve this shortage of glass filling,
It was necessary to make the length of the sealing glass 46 longer than the length of the core slit 44. However, if it was made longer, the position at the time of mounting the sealing glass became unstable, so as shown in FIG. Protruding glass guide portions 47 and 48 are provided on both sides of the glass 44 to stabilize the position when the sealing glass is placed.

In addition, the blank 4 having the above-mentioned slider structure is provided.
In the mold structure for injection molding 0, since it is desired to reduce the diameter of the sealing glass 46 and to make the interval between the glass guides 47 and 48 the same as the width of the core slit 44, As shown in FIG. 11, the mold abutting surface between the fixed mold 49 and the movable mold 50 is impossible because the mold abutting surface cannot be set at the portion c between the glass guide molding portions 53 and 54. Are located in the middle of a blank forming section 51 for forming the blank 40, and in the core slit forming section 52, the die contact surface is located at the lower end of the core slit forming section 52, Is a nose forming portion 52b.

If the mold abutment surface is forcibly set at the portion c between the glass guide portions 47 and 48, when the difference is produced, the core chip 45 cannot be inserted from above, and the core slit 44 and the nose If there is a shift of 55, there is a problem that the core chip 45 cannot be inserted.

The mold structure has a so-called side gate structure in which the gate 57 is located at the center of the side wall forming portion of the blank forming portion 51.

[0010]

In the above-mentioned conventional slider structure, when the blank 40 is fired, the shrinkage rate is 10%.
%, It is easy to deform, and as shown in FIG.
In the normal posture with the auxiliary sliding contact surfaces 42 and 43 facing upward, as shown in FIG. 13B, the contraction is limited by the frictional resistance of the portion in contact with the firing jig 58, and the trapezoid is formed. FIG.
As shown in FIG. 14 (2), when placed horizontally as in (1),
The end wall 59 is depressed inward. In addition, as shown in FIG. 15, the inverted posture in which the main and auxiliary sliding contact surface portions 42 and 43 are turned down has the least deformation. However, in this posture, the sitting position is poor due to the presence of the glass guide portions 47 and 48. Was inevitable. The blank 40 shown in FIGS. 13 (2) and 14 (2) is drawn to be extremely deformed for understanding.

Regardless of the posture, the outer reference planes 60 and 61 are deformed and undulated as shown in FIG. a and azimuth and the recording / reproducing track center b were difficult to position accurately.

In the above-described mold structure, since the mold contact surface is located at the lower end of the core slit forming portion 52,
As shown in FIG. 12, a burr 62 is formed at the lower end portion of the core slit 44, and the burr 62 supports the core chip 45. Therefore, there is a problem that a step difference between the core chip and the slider occurs, and the gap depth accuracy is deteriorated.

Further, in the mold structure, since the gate 57 is located at the center of the side wall forming portion of the blank forming portion 51, when the gate 57 is cut off after forming the blank 40, the gate remaining portion is not formed. (Protrusions) hinder assembly, and if there are no remaining gates, there is a problem in that the slider is dented and the appearance is poor.

The present invention has been made in view of the above problems, and a first object of the present invention is to stabilize the posture during firing of a blank and to minimize deformation of the blank. To provide a slider structure of a composite magnetic head.

It is a second object of the present invention to provide a composite magnetic head slider structure that can be assembled accurately with reference to an assembly reference plane.

A third object of the present invention is to form a horizontal burr on the upper end surface of the core slit forming portion, thereby making it easier to remove the burr, and to reduce the step on the lower surface of the core chip slider. An object of the present invention is to provide a molding die structure for a slider structure of a composite magnetic head which cannot be enlarged.

It is a fourth object of the present invention to provide a molding die structure for a slider structure of a composite magnetic head which improves the appearance quality of the slider regardless of the gate.

[0018]

In order to achieve the first object, a slider structure of a composite magnetic head according to the present invention comprises a main sliding contact surface portion and an auxiliary sliding contact surface portion on a sliding contact surface side of a blank. In the slider structure of the composite magnetic head having a pair of side walls and a pair of end walls on the outer periphery of the blank,
The present invention is characterized in that at least three projections having the same height are provided without being biased in either the main sliding contact surface portion or the auxiliary sliding contact surface portion of the blank.

In order to achieve the second object, the slider structure of the composite type magnetic head according to the present invention has a main sliding contact surface portion and an auxiliary sliding contact surface portion on the sliding contact surface side of the blank.
In a slider structure of a composite magnetic head having a pair of side wall portions and a pair of end wall portions on the outer periphery of a blank, the height of the blank is at least three places without being biased to either the main sliding contact surface portion or the auxiliary sliding contact surface portion of the blank. At least one assembling reference surface is provided on at least one side wall, and at least one assembling reference surface is provided on at least one end wall, or at least one end wall is provided .
At least two assembly reference planes spaced apart from each other.
At least one assembly reference plane on each side wall
It is characterized by having been provided .

In order to achieve the third object, the molding die structure of the slider structure of the composite magnetic head according to the present invention includes a die abutting surface of a die for molding a blank. It is characterized in that it is located at the upper end on the sliding contact surface side of the core slit forming portion of the mold.

According to a fourth aspect of the present invention, there is provided a molding die structure for a slider structure of a composite magnetic head according to the present invention, wherein a pin point gate is formed on an auxiliary sliding contact surface molding portion of the die. The height position of the tip of the pinpoint gate is located between the height of the auxiliary sliding contact surface when the slider is completed and the highest protrusion formed on the auxiliary sliding contact surface.

[0022]

In the slider structure of the composite type magnetic head of the present invention, at least three projections having the same height are used as the receiving surfaces when the blank is fired, so that the posture is stabilized during the firing, and Since the surface spacing is narrow, deformation is minimized.

Further, in the slider structure of the composite magnetic head of the present invention, at the time of firing the blank, three projections having the same height can be used as receiving surfaces, and the attitude can be stabilized during firing, and Since the deformation at the time of firing can be minimized, the assembly reference surface formed on the end wall portion of the blank and the assembly reference surface formed on the side wall portion do not undulate. By using the surface as a reference, the position of the recording / reproducing gap, the azimuth, and the position of the recording / reproducing track center can be accurately determined on the basis of the outer periphery when assembling the core chip.

Further, in the molding die structure of the slider structure of the composite magnetic head according to the present invention, at the time of injection molding, horizontal burrs can be formed at the upper end of the core slit molding portion on the sliding contact surface side. . By making the height of the burrs equal to or slightly higher than the height of the core chip, it becomes easier to remove the burrs, and even if a small amount of burrs remain, the burrs pass through the burrs after insertion, so that the burrs do not catch on the core chip. Therefore, the core chip slider step does not become large.

In addition, according to the molding die structure of the slider structure of the composite magnetic head of the present invention, even if the pinpoint gate cut off remains convex, it does not reach the height of the projection, Even if it is recessed, it does not hang on the finished sliding contact surface. The appearance quality is good because it does not appear on the completed sliding contact surface without sticking out when disposing and firing.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a blank having a slider structure of a composite magnetic head according to the present invention, and FIG. 2 is a plan view of the blank.

The slider structure of the composite magnetic head according to the present invention includes a substantially box-shaped blank 1 for accommodating a core chip and a coil assembly. 2, a main sliding contact surface 3 and an auxiliary sliding contact surface 4 are formed. Both of the sliding contact surface portions 3 and 4 have an elongated half-moon shape whose outer side is curved. A core slit 5 formed in the slider 1 is opened at the center of the main sliding contact surface 3, and glass guides 6 and 7 are formed on both sides of the core slit 5. The outer glass guide portion 6 is composed of protrusions 8 and 9 located at both ends thereof and a protrusion 10 located at an intermediate portion, and the end faces of these protrusions 8, 9 and 10 are flattened. The heights of the projections 8 and 9 are equal, and the height of the projection 10 in the middle portion is lower than the heights of the projections 8 and 9. Further, the inner glass guide portion 7 includes protrusions 11 and 12 located at both ends thereof and a protrusion 13 located at an intermediate portion, and end faces of these protrusions 11, 12, and 13 are flattened, The heights of the projections 11, 12, 13 are equal and are lower than the projections 8, 9 located at both ends of the outer glass guide 6.

Projections 14, 15 and 16 are formed at both ends and an intermediate portion of the auxiliary sliding contact surface 4, and the end faces of these projections 14, 15 and 16 are flat.
The heights of the projections 14 and 15 are equal at both ends, and the height of the projection 16 in the middle is lower than the projections 14 and 15.
Moreover, the height of the projections 14 and 15 at both ends is equal to the height of the projections 8 and 9 at both ends of the glass guide 6 outside the main sliding contact surface 3.

Further, a pair of short end walls 17 and a pair of long side walls 19 are formed on the outer peripheral portion of the blank 1. There Ru formed Thea. In the side wall portion 19, assembly reference surfaces 20, 20 are formed separately from each other. Furthermore, on the end wall 17
An assembly reference surface 18 is formed at two places apart from each other,
Although one assembly reference plane 20 may be formed in
The effect and effect are similar to those of the
Description is omitted.

The protrusions 8 and 9 at both ends of the main sliding contact surface 3 of the blank 1 and the protrusions 14 and 15 at both ends of the auxiliary sliding contact surface 4 have the same height and are on the same plane. In addition, as shown in FIG.
By using the receiving surfaces 4 and 15 as the receiving surfaces, the posture of the blank 1 during firing is stabilized, and in the normal position, the blank 1 is limited in contraction by the frictional resistance of the portion in contact with the firing jig 58 and becomes trapezoidal. And deformation is suppressed to a minimum because the spacing between the receiving surfaces is narrow.

As described above, since the deformation of the blank 1 during firing can be suppressed to a minimum, the shape of the blank 1 is stabilized, and the assembly reference surface 1 formed on the short-side end wall portion 17 is formed.
8 and an assembly reference plane 2 formed on the longitudinal side wall 19
Even if there are undulations at 0 and 20 due to partial non-uniform shrinkage, the time required to search for the most convex portion during measurement is shortened because the area of each of the assembly reference surfaces 18 and 20 is small. By using these assembling reference surfaces 18 and 20 as a reference, the position of the recording / reproducing gap a and the position of the azimuth and the position of the recording / reproducing track center b can be accurately determined on the basis of the outer periphery when assembling the core chip.

In order to stabilize the posture of the blank 1 during firing, the projections 8 and 9 at both ends of the main sliding contact surface 3 are required.
And the projections 14 and 15 at both ends of the auxiliary sliding contact surface portion 4 are positioned at the same height and located in the same plane. In order to stabilize the posture of the blank 1 during firing, The projections having the same height may be provided in at least three places without being biased in either the main sliding contact surface portion 3 or the auxiliary sliding contact surface portion 4 of the blank 1. Therefore, (1) of FIG.
As shown in (2) and (3), one projection 39 is formed on the auxiliary sliding contact surface 4, and this projection 39 is made the same height as the projections 8 and 9 at both ends of the main sliding contact surface 3. May be positioned in the same plane.

FIG. 5 shows a mold 21 having a mold structure for molding the blank 1 described above. The mold 21 includes a fixed mold 22 and a movable mold 23, and a mold portion 24 of the fixed mold 22 includes
A protrusion forming portion 25 for forming the protrusions 8, 9 and 10 of the main sliding contact surface portion 3, and a surface forming portion 26 for forming a portion between the outer glass guide portions 6 and 7 in the main sliding contact surface portion 3; And an auxiliary sliding contact surface forming portion 27 for forming the auxiliary sliding contact surface portion 4 and a clearance reference surface forming portion 28 for forming the clearance reference surface 2.
A pinpoint gate 35 is formed at a protrusion forming portion 27a at an intermediate portion of the auxiliary sliding contact surface forming portion 27. As shown in FIG. 8, the height H of the tip of the pinpoint gate 35 is near the middle between the height H1 of the sliding contact surface when the blank 1 is completed and the height H2 of the highest protrusion of the blank 1. is there.

The mold portion 29 of the movable mold 23 is formed by forming an outer shape forming portion 30 for forming a box-shaped outer shape of the blank 1 and a portion of the main sliding contact surface portion 3 excluding the projections 8, 9, and 10. Forming portion 31 and projections 14 and 15 of auxiliary sliding contact surface 4
It has a forming part 32 for forming the part excluding the part 16 and a core slit forming part 33 for forming the core slit 5. The forming surface of the end wall part 17 on the short side of the outer shape forming part 30 has A molding portion (not shown) of the assembly reference surface 18 is formed, and a molding portion 34 of the assembly reference surface 20 is formed on the molding surface of the side wall portion 19 on the longitudinal side of the external shape molding portion 30.

The mold abutting surface of the mold 21 is formed by the mating portion 36 of the fixed mold 22 and the movable mold 23 and the surface portion forming portion 26 of the fixed mold 22 and the core slit forming portion 33 of the movable mold 23. It is butted at a joint 37 with the tip surface 33a. The width dimension L1 of the surface forming section 26 of the fixed mold 22 is larger than the width dimension L2 of the core slit forming section 33, and L1−L2 = 0.02 to about 0.1 mm. The lower limit of this value, 0.02 mm, is equal to or larger than the size of the displacement between the fixed mold 22 and the movable mold 23.

In the above-described embodiment of the mold structure, since the mold abutting surface of the mold 21 is located on the upper end surface 33a of the core slit forming portion 33 of the mold 21, the injection is performed. In the blank 1 after molding, FIGS. 6, 7 (1),
As shown in (2), a burr 7 is provided beside the end of the core slit 5.
0 comes out. The height H3 of the burr 70 is made equal to or slightly higher than the height of the core chip 45, so that the burr can be easily removed.
After insertion, the burr 70 passes through the burr 70 and the burr 70 does not catch on the core chip 45, so that the step difference between the core chip and the slider does not increase. Further, as shown in FIG. 7 (2), since the burr 70 is well visible at the upper portion, deburring can be performed with a barrel or the like, and it is not necessary to remove the burr by hand one by one. Further, as shown in FIG. 7 (3), the glass guides 6, 7 are divided into six parts by the projections 8, 9, 10, 11, 12, 13, so that the burr 70 can be seen well and the barrel 70 can be seen. Deburring can be performed by such means.

Further, since the die contact surface is located on the upper end surface 33a of the core slit forming portion 33,
End wall portion 1 of outer shape forming portion 30 of mold portion 29 of movable mold 23
Since the height H4 of the molding surface of the side wall portion 7 and the side wall portion 19 can be made large and the pinpoint gate 35 is provided in the auxiliary sliding contact surface molding portion 27, the molding surface of the end wall portion 17 and the side wall portion 19 is formed. The formed portion 34 of the reference surface 20 to be formed can be widened, and a wide assembly reference surface can be formed.

Further, since the die contact surface is located on the upper end surface 33a of the core slit forming portion 33,
Processing of the fixed mold 22 and the movable mold 23 becomes easy. Also,
A pin point gate 35 is formed in the auxiliary sliding contact surface forming portion 27 of the mold body 21, and the height position H of the tip of the pin point gate 35 is defined as the auxiliary sliding contact surface height H 1 when the slider is completed and the auxiliary sliding surface. Protrusions 14, 15 formed on contact surface 4
Of the pinpoint gate 35 even when the pinpoint gate 35 is separated from the projection H1.
It does not reach the height of 4, 15 and does not cover the finished sliding contact surface even if it is recessed, and it does not protrude and hinder it when it is laid down and fired, so it does not appear on the finished sliding contact surface, so the appearance quality is good .

[0039]

As described above, the slider structure of the composite magnetic head according to the present invention has a main sliding contact surface portion and an auxiliary sliding contact surface portion on the sliding contact surface side of the blank, and a pair of side walls on the outer periphery of the blank. In the slider structure of the composite type magnetic head having a portion and a pair of end wall portions, at least three protrusions having the same height are provided without being biased by any of the main sliding contact surface portion and the auxiliary sliding contact surface portion of the blank. Therefore, when the blank is fired, the protrusions having three equal heights are used as receiving surfaces, whereby the posture is stabilized during firing, and the spacing between the receiving surfaces is narrow, so that deformation can be minimized.

The slider structure of the composite magnetic head according to the present invention has a main sliding contact surface portion and an auxiliary sliding contact surface portion on the sliding contact surface side of the blank, and a pair of side wall portions and a pair of end wall portions on the outer periphery of the blank. In the slider structure of the composite magnetic head having a portion, at least three projections having the same height are provided at least at three places without being biased to any of the main sliding contact surface portion and the auxiliary sliding contact surface portion of the blank. Since two assembly reference planes that are separated from each other and at least one assembly reference plane are provided on at least one end wall, three projections having the same height are formed on the receiving surface when the blank is fired. As a result, the posture during firing is stabilized, and the deformation during firing of the blank can be minimized, so that the assembly reference surface formed on the end wall portion of the blank and the assembly reference surface formed on the side wall portion are reduced. Even if it hits, there is little influence due to the limited area of the assembly reference plane. By assembling the core reference chip, the recording / reproducing gap and azimuth based on the outer circumference and the recording / reproducing track can be set based on these assembly reference planes. The center can be accurately positioned, and the assembly can be performed accurately by using the assembly reference plane as a reference.

Further, in the molding die structure of the slider structure of the composite magnetic head according to the present invention, the die abutting surface of the die for forming the blank is moved to the sliding contact surface side of the core slit forming portion of the die. Because it is located at the upper end, during injection molding,
Lateral burrs can be formed on the end surface of the core slit forming portion. By making the burr height equal to or slightly higher than the chip height, it becomes easier to remove the burr, and even if a little burr remains, the chip passes through the burr section after inserting the chip, so it does not catch on the chip, so the core chip・
The slider step does not increase.

Further, in the molding die structure of the slider structure of the composite magnetic head according to the present invention, a pin point gate is formed on the auxiliary sliding contact surface forming portion of the die, and the height position of the tip of the pin point gate is determined. Since the slider is located between the height of the auxiliary sliding contact surface at the time of completion of the slider and the highest of the protrusions formed on the auxiliary sliding contact surface, even if the mark that separates the gate remains in a convex shape, It does not reach the height and does not hang on the finished sliding contact surface even if it is recessed. The appearance quality is good because it does not appear on the completed sliding contact surface without sticking out when disposing and firing.

[Brief description of the drawings]

FIG. 1 is a perspective view of a blank of a slider structure of a composite magnetic head according to the present invention.

FIG. 2 is a plan view of the blank.

FIG. 3 is an explanatory diagram of an inverted posture during firing of the blank.

FIG. 4A is a plan view illustrating a modified example of a protrusion on the main and auxiliary sliding contact surfaces of the blank. (2) is explanatory drawing in planar view of another modification of the protrusion part in the main and auxiliary sliding contact surface parts of the same blank. (3) It is explanatory drawing in planar view of another modification of the projection part in the main and auxiliary sliding contact surface parts of the same blank.

FIG. 5 is a cross-sectional view of a molding die structure of a slider structure of the composite magnetic head according to the present invention.

FIG. 6 is an explanatory diagram of burr height in a blank injection-molded with the same mold structure.

FIG. 7 (1) is an explanatory diagram of a side view of a burr in the blank. (2) is an explanatory view of a burr of the blank in a plan view. (3) is an explanatory view of a burr in a plan view of the entire main sliding contact surface portion of the blank.

FIG. 8 is an explanatory view of the pinpoint gate in the blank as viewed from the side.

FIG. 9 is a perspective view of a blank having a slider structure of a conventional composite magnetic head.

FIG. 10 is a perspective view of a blank having a slider structure of a conventional composite magnetic head.

FIG. 11 is a sectional view of a molding die structure of a slider structure of a conventional composite magnetic head.

FIG. 12 is an explanatory diagram of burr height in a blank injection-molded with the same mold structure.

FIG. 13 (1) is an explanatory view of a normal posture when the blank is fired. (2) is explanatory drawing of the deformation | transformation after baking of the same blank.

FIG. 14 (1) is an explanatory view of a horizontal posture during firing of the blank. (2) is explanatory drawing of the deformation | transformation after baking of the same blank.

FIG. 15 is an explanatory diagram of an inverted posture during firing of the blank.

FIG. 16 is a plan view of a deformation of the blank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Blank 3 Main sliding contact surface part 4 Auxiliary sliding contact surface part 8, 9, 14, 15 Projection part 17 End wall part 19 Side wall part

Claims (4)

(57) [Claims] 1. A slider structure of a composite magnetic head having a main sliding contact surface portion and an auxiliary sliding contact surface portion on a sliding contact surface side of a blank, and a pair of side walls and a pair of end walls on an outer periphery of the blank. A slider structure for a composite magnetic head, wherein at least three protrusions having the same height are provided without being biased in either the main sliding contact surface portion or the auxiliary sliding contact surface portion of the blank. 2. A slider structure of a composite magnetic head having a main sliding contact surface portion and an auxiliary sliding contact surface portion on a sliding contact surface side of a blank, and a pair of side walls and a pair of end walls on the outer periphery of the blank. Protrusions having the same height are provided in at least three places without being biased in either the main sliding contact surface portion or the auxiliary sliding contact surface portion of the blank, and are separated from each other on at least one side wall portion.
At least one assembly reference surface is provided on at least one end wall , or at least one assembly reference surface is provided .
Two assembly reference planes separated from each other on one end wall
And at least one assembly on at least one side wall
A slider structure of a composite magnetic head, wherein each slider has a reference surface . 3. A slider structure of a composite type magnetic head, wherein a die abutting surface of a die for forming a blank is located at an upper end of a slide slit surface of a core slit forming portion of the die. Mold structure for molding. 4. A pin point gate is formed in an auxiliary sliding contact surface forming portion of a mold, and the height position of the tip of the pin point gate is formed on the auxiliary sliding contact surface height when the slider is completed and the auxiliary sliding contact surface portion. A molding structure for a slider structure of a composite magnetic head, wherein the molding structure is located between the highest one of the protrusions.