JP3782277B2 - Suspension for disk drive - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention, for example, relate to Suspension for a disk drive incorporated in the information processing apparatus such as a personal computer.
[0002]
[Prior art]
2. Description of the Related Art A hard disk drive (HDD) for recording and reproducing information on a rotating magnetic disk or magneto-optical disk has a carriage that can pivot about an axis. The carriage is driven to rotate around the axis by a positioning motor.
[0003]
For example, as described in US Pat. No. 4,167,765, a carriage includes an arm, a suspension provided at the tip of the arm, a head portion including a slider attached to the suspension, and the like. ing. When the disk rotates at a high speed, the slider slightly floats from the disk, and an air bearing is formed between the disk and the slider.
[0004]
The suspension includes a load beam made of a precise thin plate spring, a flexure made of a very thin plate spring fixed to the tip of the load beam by laser welding or the like, and a laser weld to the base of the load beam. It consists of a base plate fixed by etc. The base plate is fixed to the suspension mounting surface of the arm.
[0005]
In such a disk drive, there is a tendency that information to be recorded has a higher density and a higher rotation speed of the disk. Therefore, disk drive suspensions are required to have excellent vibration characteristics that can be accurately positioned with respect to the recording surface of the disk, and to be less susceptible to wind turbulence caused by higher disk rotation. The Moreover, this type of suspension also tends to be subjected to more complicated processing in order to cope with various newly required functions.
[0006]
[Problems to be solved by the invention]
The suspension is required to have higher rigidity and a lower spring constant as the disk density increases. However, conventionally, since the rigid body portion 2a having the length L1 and the spring portion 2b having the length L2 are integrated as the load beam 2 of the suspension 1 shown in FIG. 11, the rigid body portion 2a is required. It is difficult to simultaneously satisfy the performance (high rigidity) and the performance (low spring constant) required for the spring portion 2b.
[0007]
In particular, since the material portion and the plate thickness of the rigid body portion 2a are restricted by the spring portion 2b, the bending edge 3 is formed by bending both side edges of the rigid body portion 2a in order to increase the rigidity of the rigid body portion 2a. Or the ribs 4 have to be formed by embossing. For this reason, the load beam 2 needs to be processed with high accuracy, which requires a large number of processing steps and high costs.
[0008]
In addition, the bent edges 3 and ribs 4 formed on the load beam 2 cause the flow of the wind to be hindered, so that the disk is easily affected by wind turbulence when the disk rotates at a high speed, and the load beam 2 flutters. . A base plate 5 is fixed to the base of the load beam 2. A flexure 6 is fixed to the tip of the load beam 2. A slider 8 constituting the head unit 7 is attached to the flexure 6.
[0009]
In order to reduce the spring constant of the load beam, it has also been proposed to partially reduce the plate thickness of the spring portion by partial etching, for example, as in the load beam described in JP-A-9-191004. However, there is a limit to accurately controlling the plate thickness of the spring portion by partial etching, and there is a problem that the plate thickness of the spring portion becomes unstable and the spring constant tends to vary.
[0010]
Further, like the suspension described in Japanese Patent Laid-Open No. 9-128919, a plurality of narrow leaf spring-like portions are formed by etching or pressing around the slider mounting portion of the load beam, and these leaf spring shapes are formed. There has also been proposed one obtained by deforming this part in the thickness direction. However, in this conventional example, it is necessary to form the leaf spring portion in a narrow region at the tip of the load beam. For this reason, extremely delicate processing is required, and the shape of the beam and the spring constant are likely to vary, and the quality is not stable. There is a problem.
[0011]
Accordingly, an object of the present invention is to provide a Suspension for high performance disk drives that can be meet the required performance.
[0012]
[Means for Solving the Problems]
To achieve the above object, a suspension according to the present invention includes a base plate, a load beam attached to the base plate, and a flexure mounted on the side of the load beam opposite to the disk and provided with a head portion. In the above suspension, the load beam is made of stainless steel or light metal and is separated and independent from the base plate, and the rigid body portion to which the flexure is fixed is configured separately from the rigid body portion and the flexure. wherein is a spring member made of stainless steel that connects the base plate is arranged on the side facing the same Ku disk and the flexure relative to the base plate and the rigid part secured to overlap the end portion of the rigid part and the bundled members And the spring portion An opening which opens between the formed and an end portion of the base plate and the end portion of the rigid portion, the spring portion the spring constant is lower than formed on both sides of the opening the rigid portion, the edge of the base plate Bending portions formed on the respective spring portions by bending the lengthwise intermediate portion of the spring member into a shape in which the opposite side to the disk is convex between the end portion and the end portion of the rigid body portion have.
[0013]
In the suspension according to the present invention, the rigid body portion and the spring portion constituting the load beam are separate parts. Therefore, in order to satisfy the performance required for the suspension, the material or plate thickness of the rigid body portion and the spring portion are individually set. Selected. For example, a plate having a large plate thickness is employed for the rigid portion of the load beam, and a spring member having a high accuracy and a low spring constant made of a rolled steel material having a small plate thickness is employed for the spring portion.
[0014]
Stainless steel may be used for the rigid part of the load beam, but it is made of light metal (metal lighter than Fe) such as Al, Ti, or synthetic resin, making it lighter and more rigid. It is also possible to achieve both. Alternatively, the load beam or the like is composed of a composite material (cladding material) made of two or more materials obtained by laminating a light metal such as aluminum or titanium or an alloy mainly composed thereof and other metal (for example, stainless steel). May be. The flexure and the spring portion may be configured by a single plate that is integrally connected to each other, so that parts can be shared.
[0015]
In the process of manufacturing the suspension according to the present invention, a semi-finished suspension having a base plate, a rigid portion of the load beam, and a connecting portion for connecting them together can be adopted. The connecting portion projects on both sides of the spring member in a state where the spring member is overlapped with the base plate and the rigid body portion. After fixing the spring member separately from the suspension semi-finished product to the base plate and the rigid body portion of the suspension semi-finished product, the connecting portion is separated from the base plate and the rigid body portion.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described below with reference to FIGS. A hard disk drive (HDD) 10 shown in FIG. 3 has a carriage 12 that can pivot about a shaft 11. The carriage 12 is driven to turn about the shaft 11 by a positioning motor 13 such as a voice coil motor.
[0017]
The carriage 12 includes a plurality of arms (actuator arms) 16, a suspension 17 attached to the distal end portion of each arm 16, a head portion 18 provided at the distal end portion of each suspension 17, and the like. When the carriage 12 is driven by the motor 13, the head unit 18 moves to a desired track on the disk 19.
[0018]
The head unit 18 includes a slider 20 provided at a position facing the track of the disk 19, a transducer (not shown) held by the slider 20, and the like. When the disk 19 rotates at a high speed, the air that enters between the disk 19 and the slider 20 slightly floats from the disk 19, and an air bearing is formed between the disk 19 and the slider 20.
[0019]
As shown in FIG. 1, the suspension 17 includes a base plate 30 and a load beam 31 attached to the base plate 30. As shown in FIG. 3, the base plate 30 is fixed to the arm 16. The base plate 30 is formed with a circular hole 33 into which a boss portion (not shown) of the arm 16 is inserted.
[0020]
As shown in FIG. 2, the load beam 31 includes a rigid body portion 40 that is separated and independent from the base plate 30, and a spring portion 42 including a spring member 41 that is fixed to the rigid body portion 40. The rigid body portion 40 is thicker than the plate thickness of the spring member 41. In FIG. 1, the length L is a region that functions as the spring portion 42. The spring portion 42 has a smaller spring constant than the rigid portion 40 and is easily bent. In the illustrated example, the rigid body portion 40 is made of a light alloy such as an aluminum alloy and has an opening 45 penetrating in the thickness direction in order to achieve both weight reduction and high rigidity. The rigid body portion 40 may be a composite material formed by laminating a light alloy plate such as aluminum and a stainless steel plate.
[0021]
Instead of the opening 45, a recess whose thickness is reduced by etching or the like may be formed. As the material of the load beam 31, a light metal such as Ti or Al alloy (a metal having a specific gravity smaller than Fe), a composite material of an Al alloy and stainless steel, or a synthetic resin may be used. By doing so, the weight can be reduced and the frequency characteristics and vibration characteristics are improved. The load beam 31 may be bent as necessary.
[0022]
The plate-like spring member 41 constituting the spring portion 42 is made of, for example, a thin stainless steel rolled plate having spring properties, and one end portion 41a thereof is fixed by laser welding or the like in a state of being overlapped with the end portion 40a of the rigid portion 40. Has been. The other end 41b of the spring member 41 is overlaid on the base plate 30 and fixed by laser welding or the like.
[0023]
As a means for fixing the spring member 41 to the rigid body portion 40 of the load beam 31, an adhesive may be used instead of welding. When the rigid body portion 40 is made of a synthetic resin, the resin material is poured into the mold and cured with the spring member 41 set in a mold for molding the rigid body portion 40, and the spring member 41 is fixed to the rigid body portion by so-called in-mold molding. 40 may be fixed.
[0024]
A flexure 50 made of an extremely thin leaf spring is attached to the rigid portion 40. The flexure 50 is made of, for example, a stainless steel rolled material, and is fixed to the load beam 31 by laser welding or the like. As shown in FIG. 2, a convex portion 51 is provided at the end 40 b of the rigid portion 40. The convex portion 51 is in contact with the tongue portion 52 of the flexure 50. The convex portion 51 protrudes toward the tongue portion 52. The slider 20 constituting the head unit 18 is attached to the flexure 50.
[0025]
The suspension 17 configured as described above is required for the rigid body portion 40 because the rigid body portion 40 and the spring portion 42 constituting the load beam 31 are configured as separate parts, and materials and plate thicknesses suitable for each can be selected. Performance (for example, high rigidity) and performance required for the spring portion 42 (for example, low spring constant) can be easily achieved. Moreover, the spring part 42 with the stable low spring constant is obtained by using a highly accurate rolling material for the spring member 41. FIG.
[0026]
Since the load beam 31 of this embodiment can use a plate having a large plate thickness, the load beam 31 has a shape that does not obstruct the air flow as compared with the case of providing bent edges and ribs as in the conventional example shown in FIG. Even if the disk rotates at high speed, the influence of wind turbulence is reduced.
[0027]
FIG. 4 shows a suspension 17A according to a second embodiment of the present invention. The spring portion 42 of the suspension 17 </ b> A has a bent portion 60 formed by bending the lengthwise intermediate portion of the spring member 41. Since the other configuration is the same as that of the suspension 17 of the first embodiment, the same reference numerals are given to the same portions as those of the first embodiment, and the description thereof is omitted.
[0028]
FIG. 5 shows a suspension 17B according to a third embodiment of the present invention. In the suspension 17B, an opening 61 is formed at the center of the spring member 41, and both sides of the opening 61 function as spring portions 42 having a low spring constant. Further, the bent portion 60 is formed by bending a part of the spring member 41. Since the other configuration is the same as that of the first embodiment, the same reference numerals are given to the same portions as those of the first embodiment, and description thereof will be omitted.
[0029]
FIG. 6 shows a suspension 17C according to a fourth embodiment of the present invention. The suspension 17C includes a so-called arm-type long base plate 30C having an arm portion and a flexure 50C with wiring. In the flexure 50C with wiring, a conductive path 66 is formed on the surface of a metal substrate 65 such as a thin stainless steel rolled plate having spring properties through an electric insulating layer. One end of the conductive path 66 is electrically connected to the terminal 67 of the head portion 18, and the other end of the conductive path 66 is electrically connected to the terminal 68 provided on the base plate 30C. A bent portion 60 and an opening 61 are formed in a part of the spring member 41. Since the other configuration is the same as that of the first embodiment, the same reference numerals are given to the same portions as those of the first embodiment, and description thereof will be omitted. The arm portion of the arm-type base plate 30C is also made of a light metal such as Ti or Al alloy (a metal having a specific gravity smaller than Fe), a composite material made of Al and stainless steel, or a synthetic resin. By using it, the weight can be reduced and the frequency characteristics and vibration characteristics can be improved.
[0030]
FIG. 7 shows a suspension 17D according to a fifth embodiment of the present invention. The suspension 17D is manufactured using a suspension semi-finished product 70 as shown in FIG. The suspension semi-finished product 70 includes a base plate 30, a rigid body portion 40 of the load beam 31, and a pair of left and right connecting portions 71 that connect the base plate 30 and the rigid body portion 40. As shown in FIG. 7, the connecting portion 71 projects to both sides of the spring member 41 when the spring member 41 is overlapped with the base plate 30 and the rigid body portion 40.
[0031]
The spring member 41 is overlapped over both the rigid body portion 40 and the base plate 30 of the suspension semi-finished product 70, and the spring member 41 is fixed to the base plate 30 and the rigid body portion 40 by, for example, laser welding. After that, the connecting portion 71 is separated from the rigid body portion 40 and the base plate 30 by a press or the like.
[0032]
According to this embodiment, before the spring member 41 is fixed to the suspension semi-finished product 70, since the base plate 30 and the rigid body portion 40 are one component connected by the connecting portion 71, the handling is easy. In addition, the relative position between the rigid body portion 40 and the base plate 30 can be more accurately regulated.
[0033]
FIG. 9 shows a suspension 17E according to a sixth embodiment of the present invention. In the suspension 17E, a spring portion 42 and a flexure 50 are formed by a single plate-like spring member 41E. In this case, the spring part 42 and the flexure 50 are integrated, so that parts can be shared. Similarly to the suspension semi-finished product 70 of the sixth embodiment, the rigid body portion 40 and the base plate 30 are connected by the connecting portion 71, and after the spring member 41E is fixed to the suspension semi-finished product 70, the connecting portion 71 is cut off. I have to.
[0034]
FIG. 10 shows a suspension 17F according to a seventh embodiment of the present invention. In the suspension 17F, a spring portion 42 and a portion 80 laminated on the base plate 30 are integrally formed on a single plate-like spring member 41F constituting the flexure 50F with wiring. The flexure 50F with wiring is obtained by forming a conductive path 66 on the surface of a metal substrate 65 such as a thin stainless steel rolled plate having a spring property through an electrical insulating layer, and one end of the conductive path 66 is a terminal of the head portion. The other end of the conductive path 66 is connected to a terminal 68 provided in the portion 80 laminated on the base plate 30. The rigid body portion 40 and the base plate 30 of this embodiment are connected by a connecting portion 71 as in the suspension semi-finished product 70 of the sixth embodiment, and after fixing the spring member 41F to the suspension semi-finished product 70, the connecting portion 71 is I try to remove it.
[0035]
In implementing the present invention, it goes without saying that suspension components such as the base plate and the load beam, the flexure, the rigid body portion, and the spring member can be variously modified without departing from the gist of the present invention. .
[0036]
【The invention's effect】
According to the first aspect of the present invention, the material and plate thickness of the rigid portion constituting the load beam are not restricted by the spring portion, and it is possible to select an appropriate material and plate thickness according to each requirement. The performance required for the suspension can be satisfied. For example, if a plate having a large plate thickness is employed for the rigid portion of the load beam, the rigidity can be further increased and the air resistance of the rigid portion can be reduced without bending bending edges and ribs. For this reason, the influence of wind turbulence at the time of high disk rotation is reduced, and the occurrence of suspension flutter (suspension flapping of the wind) can be suppressed.
[0037]
The suspension according to the present invention can provide a stable spring portion having a low spring constant, and a suspension having both the accuracy of the spring portion and a low spring constant can be obtained. Since the rigid portion and the spring portion of the load beam are separate, a material softer than the spring portion can be used for the rigid portion, and the degree of freedom of processing such as pressing when forming the rigid portion is increased.
[0038]
According to the invention described in claim 2, by adopting a low specific gravity material such as Al alloy, Ti alloy or synthetic resin as the material of the load beam, the load beam can be reduced in weight, and the frequency characteristics are improved. Vibration characteristics are also improved.
[0039]
According to the invention described in claim 3 and claim 4, the specific gravity of the load beam or arm type long base plate is made of a composite material of two or more kinds of materials including Al alloy, Ti alloy, or these light alloys. By adopting the material, it is possible to reduce the weight of the load beam, improve the frequency characteristics, and improve the vibration characteristics. Further, by using the low specific gravity material for both the load beam and the base plate, the suspension as a whole can be further reduced in weight and the speed of the disk drive can be increased.
[0040]
According to the invention described in claim 5, by using a single plate in which the flexure and the spring portion are integrally connected, the number of parts is reduced and the positioning accuracy of the flexure and the spring portion is improved. .
[Brief description of the drawings]
FIG. 1 is a perspective view of a suspension for a disk drive showing a first embodiment of the present invention.
FIG. 2 is an exploded perspective view of the suspension shown in FIG.
3 is a cross-sectional view of a part of a hard disk drive including the suspension shown in FIG.
FIG. 4 is a perspective view of a disk drive suspension showing a second embodiment of the present invention.
FIG. 5 is a perspective view of a disc drive suspension showing a third embodiment of the present invention.
FIG. 6 is a perspective view of a suspension for a disk drive showing a fourth embodiment of the present invention.
FIG. 7 is a perspective view of a suspension for a disk drive showing a fifth embodiment of the present invention.
8 is a perspective view of a semi-finished suspension product and a spring member used in the suspension shown in FIG.
FIG. 9 is a perspective view of a disc drive suspension showing a sixth embodiment of the present invention.
FIG. 10 is an exploded perspective view of a suspension for a disk drive showing a seventh embodiment of the present invention.
FIG. 11 is a perspective view of a conventional disk drive suspension.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Disk drive 17, 17A-17F ... Suspension 18 ... Head part 30, 30C ... Base plate 31 ... Load beam 40 ... Rigid body part 41, 41E, 41F ... Spring member 42 ... Spring part 50, 50C, 50F ... Flexure 70 ... Suspension Semi-finished product 71 ... Connection part

Claims (3)

A base plate;
A load beam attached to the base plate;
A flexure mounted on the side of the load beam facing the disk and provided with a head portion;
In a suspension for a disk drive having
The load beam is
A rigid body portion made of stainless steel or light metal and separated and independent from the base plate to which the flexure is fixed;
A stainless steel spring member configured separately from the rigid body portion and the flexure to connect the rigid body portion and the base plate, and facing the disc in the same manner as the flexure with respect to the base plate and the rigid body portion And a spring member that is disposed and fixed to the end of the rigid body portion, and
An opening formed between the end of the base plate and the end of the rigid body formed in the spring member;
A spring part formed on both sides of the opening and having a lower spring constant than the rigid part;
Between the end portion of the base plate and the end portion of the rigid body portion, the intermediate portion in the longitudinal direction of the spring member is formed in each spring portion by bending it into a shape in which the opposite side to the disk is convex. A suspension for a disk drive, comprising a bent portion.   2. The disk drive suspension according to claim 1, wherein the rigid portion of the load beam is made of a light metal.   2. The suspension for a disk drive according to claim 1, wherein the load beam is made of a composite material of two or more kinds of materials including light metal.

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