JPH0254468A - Magnetic head supporting device - Google Patents

Abstract

PURPOSE:To hold a stable contact state even when the contact pressure of a magnetic head with a magnetic medium is weak by providing the rocking fulcrum of the magnetic head at a side more approaching the advancing side of the magnetic medium. CONSTITUTION:An upper magnetic head 1 and a lower magnetic head 2 are mounted on an upper carrier 7 and a lower carrier 8 via gimbal springs 3 and 4, respectively, and through grooves are provided at the springs 3 and 4, and two degrees of freedom around an X-axis and a Y-axis are supplied, and pivots 5 and 6 protruded over the carriers 7 and 8, respectively, form the rocking fulcrums by abutting at the intersection of the X-axis and the Y-axis. The rocking fulcrum G is provided at the advancing side of the magnetic medium more approaching than a central point G' on the back plane of the head 1. Therefore, the operating point Q of the contact force N of the head 1 to the magnetic medium 9 is set at a point in the neighborhood of the center of the head 1 assuming a head load W remains unchanged. As a result, it is possible to obtain the stable contact state without generating head floating even when a weak head load is applied.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a magnetic head support device for a flexible disk drive device, and particularly for high-speed flexible disks in which the relative speed between the magnetic head and the magnetic medium is high. - A magnetic head support device suitable for a drive device is provided.

BACKGROUND OF THE INVENTION In recent years, there has been a significant demand for higher speeds and higher densities for flexible disk drive devices. A flexible disk drive apparatus performs recording and reproduction by bringing a magnetic head into contact with a magnetic medium, and the quality of the contact has a significant effect on recording and reproduction characteristics. Therefore, in a magnetic head support device, the most important function is to bring the magnetic head into stable contact with the magnetic medium.

A conventional magnetic head support device will be described below with reference to the drawings. FIG. 5 is a sectional view showing the structure of a conventional double-sided magnetic head support device.

Fig. 6 is a view taken in the direction of arrow A in Fig. 5, and Fig. 7 is a view taken from B- in Fig. 5.
It is a sectional view of B. In FIG. 5, 1 is an upper magnetic head, 2 is a lower magnetic head, and gimbal springs 3 and 4 are used, respectively.
It is attached to the upper carrier 7 and the lower carrier 8 via. The gimbal spring 3.4 is provided with a groove as shown in FIG. 6, giving it two degrees of freedom around the X-X axis and the Y-Y axis. Also, behind it, as shown in FIGS. 6 and 7, are the upper carrier 7 and the lower carrier 8.
The respective projecting pivots 5.6 abut at the intersections of the X-X and Y-Y axes. Furthermore, the upper magnetic head 1 and the lower magnetic head 2 are mounted so that the center of their back surfaces coincides with the intersection of the X-X axis and the Y-Y axis. Therefore, the upper magnetic head 1 and the lower magnetic head 2 are swingable about the center of their back surfaces as a fulcrum. Furthermore, the seventh
Arrow E in the figure represents the traveling direction of the magnetic medium. Further, in FIG. 5, reference numeral 10 denotes a pressure spring for bringing the upper magnetic head 1 and lower magnetic head 2 into contact with the magnetic medium 9 with appropriate pressure.

The magnetic head support device configured in this manner allows the upper magnetic head 1 and the lower magnetic head 2 to freely swing around the center of the back surface as a fulcrum, thereby preventing deflection of the magnetic medium.
It can follow the waves.

Problems to be Solved by the Invention However, in the above configuration, when the relative speed between the magnetic head and the magnetic medium is large, so-called head floating occurs due to the dynamic pressure effect, and a problem occurs between the magnetic head and the magnetic medium. There has been a problem in that the output loss caused by the voids has an adverse effect on the recording and reproducing characteristics. Furthermore, if the load applied to the head is increased to suppress head floating, the contact force with the magnetic medium becomes excessive, resulting in a problem in that the durability of the magnetic medium deteriorates.

The factors that cause head floating will be explained below with reference to the drawings. FIG. 8 is a diagram schematically showing the configuration of a conventional magnetic head support device. In FIG. 8, reference numeral 1 denotes a magnetic head which is swingable at point G. Further, a head load W is acting on point G. In this state, when the magnetic medium 9 is run in the direction of arrow E, dynamic pressure is generated between the magnetic head 1 and the magnetic medium 9. Dynamic pressure is magnetic medium 9
It is generated by the air drawn in by the air, and as shown in FIG. 8, it occurs mostly on the air inflow side. The floating blade F that replaces this dynamic pressure with a single force
Let the point of action be point P. That is, the size of the floating blade F is equal to the sum of the above-mentioned dynamic pressures, and the point of action P coincides with the pressure center of the dynamic pressures. Let the length of the perpendicular line drawn from point G to floating blade F be a.

Next, consider the contact pressure between the magnetic head and the magnetic medium.

Although the contact pressure actually has a certain distribution as shown in FIG. 8, it is considered by replacing it with a single force N, as in the case of the dynamic pressure discussed above. Also, let the point of action be the Q point. In Figure 8, the balance of forces in the vertical direction and G
From the balance of moments around a point, the magnitude of contact force N is N=W-F... (1)
, and the length of the perpendicular drawn from point G to N, b is b=
aF/ (W-F)-μh -... (2) It is given by: Here, h is the height of the magnetic head, and μ is the coefficient of dynamic friction between the magnetic head and the magnetic medium. In addition, the force caused by the gimbal spring, the viscous resistance of the air, etc. are sufficiently small to save effort here.

FIG. 9 is a diagram showing the relationship between the force applied to the magnetic head and the head floating in a conventional magnetic head support device. The meanings of the symbols in FIG. 9 are the same as those in FIG. 8 described above. Considering the case where the relative speed between the magnetic head and the magnetic medium is relatively small, the floating blade F is small and the point of application of the contact force N is near the center of the magnetic head, as shown in FIG. 9(a). .

If the relative speed between the magnetic head and the magnetic medium is increased in this state, the number of flying edges F increases, and as is clear from equation (2), the value of b increases accordingly. In other words, the point of application of the contact force N moves to the outflow side (thereby, the balance of the moment is maintained. However, the length 2L of the sliding surface of the magnetic head is finite. Therefore, the equation (2 ) may exceed L. In other words, under the condition that the size of the floating blade is FEW (1-a/(a+L+μh)), b>L. This situation is shown in Figure 9 (b).In other words, even if b>L and the moment is balanced only when the contact force N' acts on point Q', in reality the contact force N is Therefore, the moment balance is not satisfied and a rotational force M is generated in the magnetic head.As a result, a gap is generated on the entrance side of the magnetic medium.Furthermore, as the gap increases, the levitation The blade F decreases, and at a certain point, the moments are balanced and an equilibrium state is reached.This is the so-called head floating state.

A conventional method to avoid this head floating is to increase the head load W. The situation is shown in FIG. 9(c). That is, as the head load W is increased, the value of the contact force N increases as can be seen from equation (1), and the value of b obtained from (2) can be made smaller than L.

In other words, the head load is W>F' (1+a/(L+μh
)), b<l. Therefore, the moment balance is satisfied and head floating does not occur. However, in this case, it is inevitable that the durability of the magnetic medium will deteriorate as the contact force N increases.

In conventional magnetic head support devices such as those described above, when the relative speed between the magnetic head and the magnetic medium is large, so-called head floating occurs due to the dynamic pressure effect, and the air gap created between the magnetic head and the magnetic medium. The problem has been that the output loss caused by this has an adverse effect on the recording and reproducing characteristics. Furthermore, if the load applied to the head is increased in order to suppress head floating, the contact force with the magnetic medium becomes excessive, resulting in a problem in that the durability of the magnetic medium deteriorates.

Means for Solving the Problems In order to solve the above problems, the magnetic head support device according to the present invention is capable of swinging a magnetic head having a sliding surface with a magnetic medium in the radial direction and circumferential direction of the magnetic medium. This magnetic head support device is provided with a mechanism for supporting the magnetic medium in the circumferential direction of the magnetic medium, and has a structure in which a swinging fulcrum with respect to the circumferential direction of the magnetic medium is provided closer to the magnetic medium entrance side than the center of the sliding surface.

Effect of the Invention With the above-described configuration, the present invention shortens the distance between the floating blade and the swing fulcrum that occurs as the magnetic medium rotates, thereby reducing the moment exerted by the floating blade on the magnetic head, thereby preventing head floating. Become. Therefore, even if the contact pressure between the magnetic head and the magnetic medium is slight, a stable contact state can be maintained.

Embodiment Hereinafter, a magnetic head support device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing the structure of a double-sided magnetic head support device in an embodiment of the present invention. 2 is a view taken in the direction of arrow A in FIG. 1, and FIG. 3 is a sectional view taken along line BB in FIG. 1. In FIG. 1, an upper magnetic head 1 and a lower magnetic head 2 are attached to an upper carrier 7 and a lower carrier 8 via gimbal springs 3 and 4, respectively. It is similar to In addition, in FIGS. 2 and 3, the gimbal spring 3.4 is provided with a groove, giving two degrees of freedom around the X-X axis and the Y-Y axis;
Further, behind the pivots 5 and 6 projecting from the upper carrier 7 and the lower carrier 8, respectively, contact at the intersection of the X-X axis and the Y-Y axis to serve as a swinging fulcrum, as described above. This is similar to the magnetic head support device in the example. However, the magnetic head support device of this embodiment differs from the conventional magnetic head support device in the following points. That is, as described above, in the conventional magnetic head support device, the upper magnetic head l and the lower magnetic head 2 are attached so that the center of their back surface serves as the swinging fulcrum, whereas the present embodiment In the magnetic head support device in this example, as shown in FIGS. 2 and 3, the swing fulcrum of the magnetic head is provided closer to the magnetic medium entry side. Arrow E in FIG. 3 represents the traveling direction of the magnetic medium.

The magnetic head support device in this embodiment configured as above will be explained below with reference to FIGS. 4 and 8. FIG. 4 is a diagram schematically showing the configuration of the magnetic head support device in this embodiment. In FIG. 4, 1 is a magnetic head and 9 is a magnetic medium. Point G is a swing fulcrum, and is provided on the magnetic medium entry side of point G' at the center of the back surface of the magnetic head 1. The distance from point G° to point G is C
shall be. If other conditions are the same as in the conventional example shown in Fig. 8, the magnitude and distribution of the generated dynamic pressure will also be the same.
Therefore, the size of the floating blade F and its point of action P are also the same. Considering the moment around point G generated by the floating blade F in this state, it is F-a in the conventional example, but it is small as F·(a-c) in this embodiment. Therefore, if the head load W is the same, the magnetic head 1
As shown in FIG. 4, the point Q, which is the point of action of the contact force N between the magnetic medium 9 and the magnetic medium 9, is closer to the center of the magnetic head 1 than in FIG. Conversely, in order to set the point of application Q to the same point as in FIG. 8, a smaller contact force is required, that is, a smaller head load is required. In the conventional example, if the minimum head load that does not cause head floating is W m i n ', and the contact force at that time is Nm1n', then Wm1n' = (1+a
/ (i, +μh) l ... (3) Nmin'
=a F/(L+/J h)...(4
), and in this example, the minimum head load that does not cause head floating is Wm1n, and the contact force at that time is Nm.
1n, Wm1n = (1+ (a-c) / (C+L+μ
h) l F... (5) Nmin = (a-c)F/ (c+L+, czh)
・ ・ (6) It is. Since Coo, Wm1n <Wm1n',
Nm1n <Nm1n', and the magnetic head support device of this embodiment can provide a stable contact state without causing any heel/throat lifting even under a smaller head load compared to the conventional magnetic head support device. That is, since the contact force with the magnetic medium is small, the load on the magnetic medium is lightened. In particular, the above-mentioned swing center G point is the point of action P of the floating blade F.
If set on the point, Nm1 in equation (6) from a#C
n#0, indicating that even with a very slight contact force, a stable contact state can be obtained without causing any lifting or throat lifting. Also, c= (a+μh)F/W #h...
' If the above-mentioned swing center point G is set so as to satisfy (7), the point of application of the contact force N, point Q, will be directly below the head center point G. Therefore, the contact pressure will be at the center of the sliding surface of the head. The pressure distribution is such that the pressure center is at .Generally, the gap portion of a magnetic head is often provided at the center of the sliding surface, and in such a configuration, an ideal contact state is achieved.

As described above, the magnetic gutter support device of this embodiment can obtain any desired contact state by appropriately setting the position of the swing fulcrum point G of the magnetic head and the head load W. That is, if the above conditions are set to suit the durability of the magnetic medium or the position of the helad gap, an ideal contact state can always be achieved.

Effects of the Invention As described above, the magnetic head support device according to the present invention includes a mechanism for supporting a magnetic head having a sliding surface with a magnetic medium so as to be swingable in the radial direction and circumferential direction of the magnetic medium. The magnetic head support device has a structure in which a swing fulcrum with respect to the circumferential direction of the magnetic medium is provided closer to the magnetic medium entry side than the center of the sliding surface, which has advantages over conventional magnetic head support devices. Even with smaller head and throat loads, stable contact can be achieved without head floating. That is, since the contact force with the magnetic medium is small, wear and damage are reduced, and the life of the magnetic medium is increased.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of a double-sided magnetic head support device in an embodiment of the present invention, FIG. 2 is a view taken in the direction of the arrow in FIG. 1, and FIG. 3 is a sectional view taken along line B-B in FIG. 1. , FIG. 4 is an explanatory diagram schematically showing the configuration of the magnetic head support device in this embodiment, FIG. 5 is a sectional view showing the configuration of a conventional double-sided magnetic head support device, and FIG. FIG. 7 is a sectional view taken along line B-B in FIG. 5, FIG. 8 is an explanatory diagram schematically showing the configuration of a conventional magnetic head support device, and FIG. FIG. 3 is an explanatory diagram showing the relationship between the force applied to the magnetic head and the head floating in the head support device. 1... Above magnetic head, 2... Lower magnetic head, 3.4... Gimbal spring, 5.6.
·····pivot. Name of agent Patent attorney Shigetaka Awano 1 person I - Upper H & air head 2 - Lower air head 3.4 - Gimbal head 5.6 - Pivot 7 - hm carrier 8, lower IIP ! Body 9 - Temperature medium 10 - Sword blade 1 - Upper side, la! 'J'L head 2-Downward a air position 3.4--Gimbal TF height 5.6--Bipoint 7-upper m% 8-Lower W4 Camphor 9-A air medium 10-m pressure spring

Claims (1)

[Claims] A magnetic head support device includes a mechanism for supporting a magnetic head having a sliding surface with a magnetic medium so as to be swingable in the radial direction and circumferential direction of the magnetic medium, A magnetic head support device characterized in that a dynamic fulcrum is provided closer to the magnetic medium entrance side than the center of the sliding surface.