WO2014136878A1

WO2014136878A1 - Fastening structure and fastening method

Info

Publication number: WO2014136878A1
Application number: PCT/JP2014/055784
Authority: WO
Inventors: 俊充荒木; 克彦岩佐; 典拓田島; 光輝三村; 千紘伊藤
Original assignee: 日本発條株式会社
Priority date: 2013-03-08
Filing date: 2014-03-06
Publication date: 2014-09-12
Also published as: JPWO2014136878A1

Abstract

Provided are a fastening structure and a fastening method that are able to suppress the occurrence of defects arising when using a conventional disc spring or ring in the case of attaching a member in a device at a predetermined load. In the fastening structure (100), a nut (103) presses a disc (102) against the support section (101B) of a hub (101) with a disc spring (110) therebetween by means of the fastening thereof, for example. The disc spring (110) imparts a predetermined load to the disc (102). A flat surface (113B) that is inclined with respect to an inclined surface (113A) is formed at the outer peripheral portion of a concavity (113) of the main body (111) of the disc spring (110). The flat surface (113B) can contact the surface of the disc (102) when an impact arises. The amount of deflection of the disc spring (110) is, as indicated in fig. 2(B), set in a manner so that when the fastening of the nut (103) is complete, the support point (P) of the concavity (113) of the disc spring (110) is positioned at the inner peripheral portion (113C) of the flat surface (113B) or at the inner peripheral side thereof.

Description

Tightening structure and tightening method

The present invention relates to a tightening structure and a tightening method for assembling a member in an apparatus with a predetermined load using a clamp member, and more particularly to an improvement of a tightening technique using a disc spring as a clamp member.

In various devices, a clamp member is used to assemble a member with a predetermined load in the device. As the clamp member, for example, a disc spring or a ring (resin ring or metal ring) is used. For example, in a hard disk drive (HDD), when a disk is assembled in the apparatus, a clamp member is used to press and hold the disk against a hub with a constant load (for example, Patent Document 1).

JP 2006-65959 A

In a hard disk drive (HDD), it is desirable to set a large contact area between the disk and the hub in order to suppress disk deformation when an impact occurs. Further, in order to press and hold the disk with a constant load, it is desirable that the clamp member has an area where the load change with respect to the deflection amount is small in the load characteristics. However, it has been difficult for conventional disk springs and rings to satisfy both of the required characteristics.

For example, when the disc spring 11 is used as a clamp member as shown in FIG. 8A, the disc spring 11 has a region (for example, a substantially flat region) where the load change with respect to the deflection amount is small as shown in FIG. 8B, for example. Since the non-linear load characteristic is shown, the disk 2 can be held with respect to the hub 1 in a region where the load change with respect to the deflection amount is small. This facilitates holding of the disk 2 with a constant load. Moreover, compared with the case where another elastic member is used, it can satisfy | fill the load requested | required by space saving. However, since the contact between the lower end of the outer periphery of the disc spring 11 and the disk 2 is a line contact, the contact area becomes small. Reference numeral 3 denotes a fixing member. Reference numeral O denotes a rotation center axis (a chain line).

For example, as shown in FIG. 9A, when the ring 12 is used as the clamp member, the contact between the ring 12 and the disk 2 is a surface contact, so that the contact area becomes large. However, the load characteristic of the ring 12 exhibits linearity, for example, as shown in FIG. 9B, and its spring constant increases. When the spring constant is high, the load fluctuation becomes large with respect to the small fluctuation of the deflection amount as shown in FIG. Also, when the spring constant is high, after assembling, for example, when the fixing condition by the fixing member 3 is weakened with time, the distance between the disk 2 and the fixing member 3 is increased, and the amount of deflection is reduced. As shown in FIG. 9 (B), the load fluctuation increases with a small decrease in the deflection amount. When such a ring 12 has a high spring constant, it is difficult to hold the disk 2 with a constant load.

Therefore, an object of the present invention is to provide a technique capable of suppressing the occurrence of the above-described problems that occur when a conventional disc spring or ring is used in a structure in which members are assembled with a predetermined load in the apparatus.

The inventor interposes a clamping member for pressing the pressed member between the tightening member and the pressed member (for example, a disk in the case of a hard disk device), and presses the clamped member by tightening the clamping member. We have intensively studied the fastening technology (fastening method and fastening structure) for pressing and holding the member against the support member. Specifically, in such a tightening technique, the above-described conventional disc spring is described with respect to a configuration using a disc spring that can press and hold a pressed member (for example, a disk) with a constant load as a clamp member. We intensively studied how to suppress the occurrence of defects. As a result, not only the shape of the outer peripheral side end of the concave surface of the disc spring is improved, but also the state of the disc spring at the time of completion of assembly is devised to suppress the occurrence of the above problems of the conventional disc spring. As a result, the present invention has been completed.

In the tightening structure of the present invention, a clamp member for pressing the pressed member is interposed between the tightening member and the pressed member, and the pressed member is clamped to the support member by tightening the tightening member. A clamping structure for pressing and holding, wherein a disc spring is used as a clamp member, and the disc spring is formed on the outer peripheral end side of the concave surface and is inclined with respect to one surface on the inner peripheral side of the concave surface The disc spring is arranged such that the concave surface faces the pressed member and the convex surface faces the clamping member. The deflection amount of the disc spring is such that the support point of the concave surface is flat. It is set so that it may be located in an inner peripheral side edge part or the inner peripheral side rather than it.

In the tightening structure of the present invention, the disc spring as the clamp member is disposed such that the concave surface faces the pressed member and the convex surface faces the tightening member. In this case, the flat surface inclined with respect to one surface on the inner peripheral side of the concave surface is provided on the outer peripheral end portion side of the concave surface of the disc spring facing the pressed member side, on which deformation at the time of occurrence of impact is preferably suppressed. Is formed. Since such a flat surface can come into surface contact with the pressed member when an impact occurs, the contact area between the disc spring and the pressed member is increased. As a result, it is possible to suppress the deformation of the pressed member when an impact occurs.

Here, in the present invention, the surface contact between the flat surface of the disc spring and the pressed member may or may not be realized when the tightening of the tightening member is completed, and it is important that it can be realized when an impact occurs. It is. In the load characteristics (load / deflection amount characteristic curve) of the disc spring, the area where the above-mentioned surface contact can be realized when an impact occurs is within a predetermined range of the deflection amount. Strict control over quantity is not required.

In addition, since a disc spring showing a non-linear load characteristic having a small load change area with respect to the deflection amount in the load characteristic is used as the clamp member, the pressed member is supported in the load characteristic with a small load change area with respect to the deflection amount. Against and can be held. This facilitates holding the pressed member with a constant load. In the load characteristics, it is most desirable to use a substantially flat region in which the load change with respect to the deflection amount is 0 or substantially 0. However, it is not always necessary to use the substantially flat region. A sufficient effect can be obtained as compared with the case of the ring.

Here, in the present invention, there is a tendency that the tightening by the tightening member tends to be weakened with time when the apparatus is used after the tightening of the tightening member is completed. Since it is set so as to be located on the inner peripheral side end portion of the surface or on the inner peripheral side thereof, it is stronger than the case where the surface contact is completely realized to the extent that the pressed member is not defective. Can be tightened. Thereby, even if the tightening condition becomes weak as described above, the pressed member can be held with a constant load.

In addition, if the amount of deflection is set when the tightening of the tightening member is completed, the set amount of deflection is within the increase range of the amount of fluctuation in the load. By using the load fluctuation amount as an index in controlling the tightening amount with a torque wrench, the tightening amount can be easily controlled.

The fastening structure of the present invention can use various configurations. For example, the flat surface of a disc spring can use the aspect formed by plate | board thickness reducing as it goes to an outer peripheral side from an inner peripheral side. Moreover, the flat surface of a disc spring can also be made into the aspect formed by bending the boundary part of an inner peripheral side edge part and the site | part which adjoins it. In this aspect, the flat surface of the disc spring can be obtained by bending, and the cost can be reduced as compared with the case where polishing or the like is used. Therefore, the cost of the tightening structure can be reduced.

For example, the disc spring can use a mode having a recess for accommodating the top of the fastening member. In this aspect, further space saving of the tightening structure can be achieved as compared with the normal disc spring shape. For example, the disc spring can use a multistage shape in the axial cross section. In this aspect, for example, when the support member is opposed to the concave surface of the disc spring, the shape of the disc spring can be easily matched to the shape of the support member, so that space saving of the tightening structure can be achieved.

The fastening method of the present invention is one form of a method for obtaining the tightening structure of the present invention. That is, according to the tightening method of the present invention, a clamp member for pressing the pressed member is interposed between the tightening member and the pressed member, and the pressed member is attached to the support member by tightening the tightening member. A clamping method for pressing and holding a disc spring having a flat surface as a clamp member that is formed on the outer peripheral end portion side of the concave surface and is inclined with respect to one surface on the inner peripheral side of the concave surface When the tightening of the tightening member is started, the outer peripheral end of the flat surface of the concave surface of the disc spring is brought into contact with the pressed member, and the inner peripheral side end of the convex surface of the disc spring is brought into contact with the tightening member When the tightening of the tightening member is completed, the deflection amount of the disc spring is set so that the support point of the concave surface of the disc spring is located on the inner peripheral side end of the flat surface or on the inner peripheral side thereof. Features.

The fastening method of the present invention can use various configurations. For example, a disc spring having a positioning hole is used as a disc spring, a support member having a positioning concave portion is used as a support member, and the positioning member is used for positioning the disc spring before tightening. It is possible to use a mode in which the positioning member is engaged with the positioning recess of the support member through the hole and the positioning member is detached from the positioning recess and the positioning hole after the tightening of the tightening member is completed. In this aspect, when the tightening member is tightened, it is possible to suppress the disc spring from moving relative to the pressed member in conjunction with a movement such as rotation of the tightening member. Thereby, the generation | occurrence | production of the damage, contamination, etc. of the to-be-pressed member surface can be suppressed.

According to the tightening structure or the tightening method of the present invention, it is possible to suppress the deformation of the pressed member when an impact occurs, and the pressed member is supported in a region where the load change with respect to the deflection amount is small in the load characteristics. The effect that it can press and hold | maintain with respect to a member can be acquired.

It is an axial direction sectional view showing the right half of the schematic structure of the fastening structure concerning a 1st embodiment of the present invention. 1 shows a partial configuration of a tightening structure according to a first embodiment of the present invention, in which (A) is an enlarged sectional view in an axial direction at the start of tightening of a tightening member, and (B) is when tightening of the tightening member is completed. FIG. 3C is an enlarged sectional view in the axial direction when an impact is generated when the apparatus is used. It is a figure showing an example of the load characteristic of the disc spring of the clamping structure shown in FIG. It is an axial direction sectional view showing the right half of the schematic structure of the fastening structure concerning a 2nd embodiment of the present invention. FIG. 2A shows a partial configuration of a tightening structure according to a second embodiment of the present invention, in which FIG. 3A is an enlarged cross-sectional view in the axial direction at the start of tightening of the tightening member, and FIG. FIG. 3C is an enlarged sectional view in the axial direction when an impact is generated when the apparatus is used. FIG. 5 is an enlarged cross-sectional view in the axial direction at the start of tightening of the tightening member, showing a partial configuration of a modification of the tightening structure according to the first embodiment of the present invention. FIG. 6 is a partial enlarged cross-sectional view illustrating a partial configuration of a modification example of the tightening structure according to the second embodiment of the present invention at the start of tightening of the tightening member. It is an axial direction sectional view showing the right half of a schematic configuration of a conventional hard disk device using a disc spring as a clamp member. It is an axial direction sectional view showing the right half of a schematic configuration of a conventional hard disk device using a ring as a clamp member.

DESCRIPTION OF SYMBOLS 100,200 ... Clamping structure 101,201B ... Hub (support member), 201A ... Spacer (support member), 101B ... Support part, 102,202A ... Disc (pressed member), 103 ... Nut (clamp member) 110, 110A, 210, 210A ... disc spring, 111, 211 ... main body, 111A, 211A ... hole, 112, 112P, 212, 212P ... convex surface, 113, 213, 213P ... concave surface, 113A, 213A ... inclined surface ( 113B, 213B ... flat surface, 113C, 213C ... inner peripheral side end, 113D, 213D ... outer peripheral side end, 201C ... positioning recess, 201D ... inner peripheral side recess, 203 ... bolt ( Tightening member), 211B ... positioning hole, 211C ... bolt recess (tightening member recess), 213E ... curved surface, 213F ... horizontal surface, ... concave surface of the support points.

(1) First embodiment
(1A) Tightening structure Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an axial sectional view showing the right half of the schematic configuration of the fastening structure according to the first embodiment of the present invention. 2A and 2B show a partial configuration of the tightening structure according to the first embodiment of the present invention, in which FIG. 2A is an enlarged sectional view in the axial direction at the start of tightening of the tightening member, and FIG. FIG. 4C is an enlarged sectional view in the axial direction at the time of completion of tightening, and FIG. FIG. 1 shows a state in which the disc spring is in surface contact with a disk which is a pressed member in the tightening structure. Reference symbol O denotes a rotation center axis (a one-dot chain line). Regarding the description of the direction, a direction parallel to the rotation center axis O is expressed as an axis direction, and a direction perpendicular to the direction of the rotation center axis O is expressed as a horizontal direction.

In the first embodiment, for example, the tightening structure 100 is applied to a hard disk device. The tightening structure 100 includes, for example, a hub 101 (support member). The upper portion of the hub 101 has, for example, a male screw portion 101A on the outer peripheral portion, and a support portion 101B protruding in the horizontal direction is formed at the lower end portion of the male screw portion 101A, for example.

For example, a disk 102 (member to be pressed) is supported on the upper surface of the support portion 101B of the hub 101. For example, a nut 103 (tightening member) is fastened to the male screw portion 101A of the hub 101. The inner peripheral surface of the nut 103 has a female screw portion 103 A that engages with the male screw portion 101 A of the hub 101, for example. For example, a disc spring 110 is disposed between the upper surface of the disk 102 and the lower surface of the nut 103. The nut 103 presses the disc 102 against the support portion 101 B of the hub 101 through the disc spring 110 by tightening, for example.

(1B) The disc spring disc spring 110 applies a predetermined load to the disc 102 by, for example, pressing the disc 102. The disc spring 110 includes a main body 111 having, for example, a disc shape (substantially conical shape). A hole 111A having a circular cross section, for example, is formed in the central portion of the main body 111, and the main body 111 has a ring shape when viewed from the upper surface of the main body 111, for example. The male screw portion 101A of the hub 101 is inserted into the hole portion 111A. The main body 111 has, for example, a convex surface 112 (upper surface, front surface) and a concave surface 113 (lower surface, rear surface).

Specifically, the convex surface 112 of the main body 111 is, for example, a linear surface that is inclined with respect to the horizontal direction in the axial cross section. The concave surface 113 of the main body 111 has, for example, an inclined surface 113A parallel to the convex surface 112 on the inner peripheral end portion side in the axial cross section. On the outer peripheral end side of the concave surface 113 of the main body 111, a flat surface 113B that is inclined at a predetermined angle with respect to the inclined surface 113A on the inner peripheral side is formed. The corner formed by the inclined surface 113A and the flat surface 113B is, for example, an obtuse angle.

The flat surface 113B extends linearly in, for example, the axial cross section. An inner peripheral end 113C of the flat surface 113B is connected to an outer peripheral end of the inclined surface 113A, and an outer peripheral end 113D of the flat surface 113B constitutes an outer peripheral end of the concave surface 113. The flat surface 113B is a flat surface capable of surface contact with the disk 102 as shown in FIGS. The flat surface 113B is formed, for example, by reducing the plate thickness from the inner peripheral end 113C toward the outer peripheral end 113D. In this case, the flat surface 113B may be formed by performing polishing, cutting, pressing, or the like on a plate-shaped material before performing dish molding, or polishing to a dish-shaped material after performing dish molding. Alternatively, it may be formed by performing cutting, pressing, or the like.

The elastic deformation and load characteristics (load / deflection characteristic curve) of the disc spring 110 will be described with reference to FIG. 3, for example. The amount of deflection is the difference between the height in the initial state (free state) where the disc spring 110 is not pressed and the height in the state where the disc spring 110 is pressed. The height of the disc spring 110 is the height from the lowest point of the concave surface 113 to the highest point of the convex surface 112 in the axial direction. In FIG. 3, a region where the entire flat surface 113B can be in surface contact with the mating member when an impact is generated in the use state of the apparatus is referred to as a surface contactable region, and the other region is referred to as a line contact region.

For example, the inner peripheral end of the convex surface 112 of the disc spring 110 is brought into contact with the upper member (in the example of FIG. 1, the nut 103), and the outer peripheral end 113D of the flat surface 113B of the concave 113 is set to the lower member (example of FIG. 1). Then, in the state of contact with the disk 102), the outer peripheral side end 113D of the flat surface 113B is in line contact with the lower member. In this case, the support point P of the concave surface 113 of the disc spring 110 is the outer peripheral side end 113D of the flat surface 113B.

When the upper member is moved toward the lower member, the disc spring 110 is pressed in the axial direction, and the main body 111 of the disc spring 110 is elastically deformed and bent. 3 is a deflection amount when the support point P of the concave surface 113 of the disc spring 110 shifts from the outer peripheral end 113D to the inner peripheral end 113C. An arrow N in FIG. 3 indicates a region where the support point P of the concave surface 113 of the disc spring 110 is located on the inner peripheral side end 113C or on the inner peripheral side (inclined surface 113A side).

While the support point P of the concave surface 113 of the disc spring 110 moves from the outer peripheral end 113D to the inner peripheral end 113C, the flat surface 113B of the concave 113 comes into surface contact with the lower member. The surface contact in this case includes not only surface contact of the entire flat surface 113B of the concave surface 113 but also surface contact of at least a part of the concave surface 113.

When the upper member is continuously moved toward the lower member, the main body 111 of the disc spring 110 is elastically deformed and further bent, and the support point P of the concave surface 113 of the disc spring 110 is a flat surface 113B of the concave surface 113. It moves to the inner peripheral side end 113C or the inclined surface 113A side.

The load characteristic of the disc spring 110 that performs such elastic deformation shows a substantially step-like nonlinearity. Specifically, the amount of deflection is large in the load characteristics until the support point P of the concave surface 113 of the disc spring 110 shifts from the outer peripheral side end 113D to the inner peripheral side end 113C of the flat surface 113B of the concave 113. As it becomes, the load change becomes smaller and becomes flat. When the support point P of the concave surface 113 of the disc spring 110 shifts to the inner peripheral side end 113C of the flat surface 113B or to the inner peripheral side (inclined surface 113A side) than that, the load change with respect to the deflection amount increases. As described above, the load characteristic of the disc spring 110 exhibits a substantially step-like nonlinearity.

(1C) Tightening Method The assembly procedure of the tightening structure 100 will be described mainly with reference to FIGS. 2 (A) to 2 (C). First, the disc spring 110 is disposed on the upper surface of the disk 102 provided on the support portion 101 B of the hub 101. In this case, the male screw portion 101A of the hub 101 is inserted into the hole portion 111A of the disc spring 110. The concave surface 113 of the disc spring 110 is opposed to the upper surface of the disk 102, and the outer peripheral side end 113D of the flat surface 113B of the concave surface 113 is in contact with the upper surface of the disk 102 and is in line contact with the upper surface of the disk 102. The disc spring 110 is not applied with a load, and is in an initial state in which the amount of deflection is zero in the load characteristics shown in FIG.

Next, for example, as shown in FIG. 2A, the female screw portion 103A of the nut 103 is screwed onto the upper end portion of the male screw portion 101A of the hub 101, and tightening of the nut 103 is started. In this case, the convex surface 112 of the disc spring 110 is opposed to the lower surface of the nut 103, the inner peripheral end portion of the convex surface 112 is in contact with the lower surface of the nut 103, and the outer peripheral side end portion 113D of the flat surface 113B of the concave surface 113 is In line contact with the upper surface of the disk 102. The support point P of the concave surface 113 of the disc spring 110 is the outer peripheral side end 113D of the flat surface 113B.

Subsequently, the nut 103 is continuously tightened, and the disc 102 is pressed against the support portion 101B of the hub 101 via the disc spring 110. In this case, in the load characteristics, for example, as shown in FIG. 3, the load change decreases as the deflection amount increases. When the support point P of the concave surface 113 of the disc spring 110 shifts to the inner peripheral side end 113C of the flat surface 113B or to the inner peripheral side (inclined surface 113A side) than that, the load change with respect to the deflection amount increases.

Here, in the first embodiment, as shown in FIG. 2B, for example, the deflection amount of the disc spring 110 is such that the support point P of the concave surface 113 of the disc spring 110 is within the flat surface 113B when the tightening of the nut 103 is completed. It is set so as to be located on the circumferential end 113C or on the inner circumferential side (inclined surface 113A side). In this case, in the load characteristics shown in FIG. 3, the deflection amount is set in a region (a region indicated by an arrow N) that is greater than or equal to the deflection amount S. As a result, the fastening structure 100 in which the disc 102 is held by the disc spring 110 with a predetermined load is obtained. After completing the tightening of the nut 103, a cover (not shown) may be appropriately attached to the upper surface of the tightening structure 100.

For example, as shown in FIG. 2B, when the support point P of the concave surface 113 of the disc spring 110 is located on the inner peripheral side end 113C of the flat surface 113B or on the inner peripheral side thereof, the flat surface 113B. Is slightly lifted from the upper surface of the disk 102. In the load characteristics, when using a region where the load change with respect to the deflection amount is small (for example, a region around a substantially flat region where the load change with respect to the deflection amount is zero or substantially zero), compared to the conventional ring. Since a sufficient effect can be obtained, there is no problem when using a region where the load change with respect to the deflection amount is small.

When such a tightening structure 100 is used, the disk 102 may be deformed when an impact is applied to the hard disk device including the tightening structure 100. However, since the flat surface 113B is formed on the outer peripheral end side of the concave surface 113 of the disc spring 110 adjacent to the upper surface of the disk 102, when the disk 102 is deformed, for example, as shown in FIG. The upper surface can come into surface contact with the flat surface 113B of the disc spring 110, and as a result, the deformation amount of the disk 102 can be suppressed.

As described above, in the first embodiment, the flat surface 113B of the disc spring 110 can come into surface contact with the disc 102 when an impact occurs, so the contact area between the disc spring 110 and the disc 102 is widened. As a result, it is possible to suppress the deformation of the disk 102 when an impact occurs.

Here, in the first embodiment, the surface contact between the flat surface 113B of the disc spring 110 and the disk 102 may or may not be realized when the tightening of the nut 103 is completed, and can be realized when an impact occurs. is important. In the load characteristic of the disc spring 110, since the region where the surface contact can be realized when an impact occurs is within a predetermined range of the deflection amount, it is not necessary to strictly control the deflection amount when the nut 103 is completely tightened. .

In addition, since the disc spring 110 showing a non-linear load characteristic having a small load change region with respect to the deflection amount in the load characteristic is used as the clamp member, the disc 102 is placed in the hub 101 in the load characteristic small change region with respect to the deflection amount. It is possible to press and hold the support portion 101B. This facilitates holding of the disk 102 with a constant load.

Here, in the first embodiment, the deflection amount of the disc spring 110 is set so that the support point P of the concave surface 113 is positioned on the inner peripheral side end portion 113C of the flat surface 113B or on the inner peripheral side thereof. The disc 102 can be tightened to such an extent that no trouble occurs. Thereby, for example, even when the tightening condition by the nut 103 becomes weak due to a change with time when the apparatus is used after the nut 103 is completely tightened, the disk 102 can be held with a constant load.

In addition, when the amount of deflection is set when the tightening of the nut 103 is completed, the set amount of deflection is within an increase region of the amount of fluctuation of the load. Therefore, when the nut 103 is tightened with a torque wrench, a torque wrench is used. By using the load fluctuation amount as an index in the tightening amount control, the tightening amount can be easily controlled.

(2) Second embodiment
(2A) Fastening structure FIG. 4 is an axial sectional view showing the right half of the schematic configuration of the fastening structure according to the second embodiment of the present invention. 5A and 5B show a partial configuration of a tightening structure according to the second embodiment of the present invention, in which FIG. 5A is an enlarged sectional view in the axial direction at the start of tightening of the tightening member, and FIG. FIG. 4C is an enlarged sectional view in the axial direction at the time of completion of tightening, and FIG. FIG. 4 shows a state in which the disc spring is in surface contact with a disk as a pressed member in the tightening structure.

In the second embodiment of the present invention, for example, the tightening structure 200 is applied to a hard disk device. In the second embodiment, since the aspect of the hard disk device is different from that of the first embodiment, in the tightening structure 200, the disc spring 210 is correspondingly different from the disc spring 110 of the first embodiment.

The tightening structure 200 includes, for example, a spacer 201A and a hub 201B (support member). A disk 202A (member to be pressed) is supported on the upper surface of the spacer 201A. A hub 201B is provided on the inner peripheral side surface of the spacer 201A. A positioning recess 201C is formed on the upper surface of the hub 201B. An inner peripheral recess 201D corresponding to the shape of the recess 211C of the disc spring 210 is formed in a portion where the inner peripheral end of the disc spring 210 is disposed on the upper surface of the hub 201B. At the lower end of the hub 201B, for example, a support portion 201E protruding in the horizontal direction is formed. The disc 202B is sandwiched between the lower surface of the spacer 201A and the upper surface of the support portion 201E of the hub 201B.

The inner peripheral portion of the hub 201B has a female screw portion (not shown). For example, a bolt 203 (tightening member) is fastened to the female screw portion of the hub 201B. The small diameter portion of the bolt 203 has a male screw portion (not shown) that is screwed into the female screw portion of the hub 201B. A disc spring 210 is disposed on the upper surfaces of the spacer 201A and the hub 201B. The large diameter portion (top portion) of the bolt 203 presses the disc 202A against the spacer 201A via the disc spring 210 by tightening, for example.

(2B) The disc spring disc spring 210 applies a predetermined load to the disc 202A by pressing the disc 202A, for example. For example, as shown in FIG. 4, the disc spring 210 has a main body 211 having a shape corresponding to the shape of the upper surface of the bolt 203 as a fastening member, the spacer 201 A as a support member, and the hub 201 B. A hole 211A having a circular cross section, for example, is formed in the central portion of the main body 211, and the main body 211 has a substantially ring shape when viewed from the upper surface of the main body 211, for example. A small diameter portion of the bolt 203 is inserted into the hole 211 A of the disc spring 210.

The inner peripheral side end of the main body 211 is formed with a bolt recess 211C (a tightening member recess) in which the large diameter portion of the bolt 203 is accommodated when the tightening is completed. In the main body 211, for example, a positioning hole 211B is formed at a location corresponding to the positioning recess 201C of the hub 201B. It is sufficient that at least one positioning hole 211B and positioning recess 201C are formed.

The main body 211 has, for example, a convex surface 212 (upper surface, front surface) and a concave surface 213 (lower surface, rear surface). Specifically, the concave surface 213 of the main body 211 has an inclined surface 213A that is inclined with respect to the horizontal direction in the axial cross section. The inclined surface 213A is curved, for example, in the axial cross section, and may include a linear portion. A flat surface 213B that is inclined at a predetermined angle with respect to the inclined surface 213A is formed on the outer peripheral end side of the concave surface 213 of the main body 211. The flat surface 213B extends linearly, for example, in the axial cross section. The inner peripheral side end 213C of the flat surface 213B is connected to the outer peripheral side end of the inclined surface 213A. The flat surface 213B is a flat surface capable of surface contact with the disk 202A as shown in FIGS. 4 and 5C, for example.

A curved surface 213E is formed on the outer peripheral side end 213D of the flat surface 213B. The curved surface 213E is curved, for example, in the axial cross section, and may include a linear portion. The curved surface 213E is set so as to move away from the disk 202A toward the outer peripheral side and to increase the distance from the disk 202A. A horizontal surface 213F extending to the inner peripheral side in the horizontal direction is formed at the inner peripheral end of the inclined surface 213A.

The inclined surface 213A, flat surface 213B, inner peripheral end 213C, and outer peripheral end 213D of the concave surface 213 are the inclined surface 113A, flat surface 113B, inner peripheral end 113C, and outer periphery of the first embodiment. It corresponds to the side end 113D and has the same function as the corresponding part. As a result, the disc spring 210 has a non-linearity in the load characteristics, and has a region that exhibits substantially the same load characteristics as the disc spring 110.

(2C) Tightening method The assembly procedure of the tightening structure 200 will be described with reference mainly to FIGS. 5 (A) to 5 (C). 5 (A) to 5 (C) correspond to FIGS. 2 (A) to 2 (C) used in the description of the assembly procedure of the first embodiment, and the inclined surface 213A of the concave surface 213 is flat. The surface 213B, the inner peripheral end 213C, and the outer peripheral end 213D are the inclined surface 113A, the flat surface 113B, the inner peripheral end 113C, and the outer peripheral end 113D of the first embodiment as described above. And has the same functions as those corresponding parts, and therefore the description regarding the load characteristics is omitted.

First, the disk 202B is sandwiched between the lower surface of the spacer 201A and the upper surface of the support portion 201E of the hub 201B, the disk 202A is disposed on the upper surface of the spacer 201A, and then the disc spring 210 is disposed on the upper surfaces of the disk 202A and the hub 201B. . In this case, a portion of the hub 201B where the bolt 203 is disposed is located in the hole 211A of the disc spring 210. The inner peripheral side end (the inclined surface 213A, the flat surface 213B, the inner peripheral side end 213C, the outer peripheral side end 213D, and the curved surface 213E) of the disc spring 210 is disposed on the upper surface of the disk 202A. The other inner peripheral side portion of the disc spring 210 is disposed on the upper surface of the hub 201B. In this case, in the disc spring 210, the outer peripheral end 213D of the flat surface 213B of the concave surface 213 is in contact with the upper surface of the disk 202A and is in line contact with the upper surface of the disk 202A.

Next, for example, as shown in FIG. 5 (A), the male screw portion of the bolt 203 is screwed onto the upper end portion of the female screw portion of the hub 201B, and tightening of the bolt 203 is started. In this case, the inner peripheral end portion of the convex surface 212 of the disc spring 210 is in contact with the lower surface of the bolt 203, and the outer peripheral end portion 213D of the flat surface 213B of the concave surface 213 is in line contact with the upper surface of the disk 202A. The support point P of the concave surface 213 of the disc spring 210 is the outer peripheral side end 213D of the flat surface 213B. Before starting the tightening of the bolt 203, it is preferable to insert a positioning member (not shown) into the positioning hole 211B of the disc spring 210 and engage with the positioning recess 201C of the hub 201B.

Subsequently, the bolt 203 is continuously tightened, and the disc 202A is pressed against the spacer 201A via the disc spring 210.

In this case, as shown in FIG. 5B, for example, the deflection amount of the disc spring 210 is such that the support point P of the concave surface 213 of the disc spring 210 is the inner end 213C of the flat surface 213B. Or it is set so that it may be located in the inner peripheral side (inclined surface 213A side) rather than it. When the tightening of the bolt 203 is completed, the large diameter portion of the bolt 203 is accommodated in the bolt recess 211 C of the disc spring 210. Thus, the tightening structure 200 in which the disc 202A is held by the disc spring 210 with a predetermined load is obtained. After completion of tightening the bolt 203, the positioning member may be removed from the positioning recess 201C and the positioning hole 211B, and a cover (not shown) may be appropriately attached to the upper surface of the tightening structure 200.

In the second embodiment, the following effects can be obtained in addition to the same effects as the first embodiment.

Before the tightening of the bolt 203, the positioning member is inserted into the positioning hole 211B of the disc spring 210 and engaged with the positioning recess 201C of the hub 201B. It is possible to suppress the disc spring 210 from moving relative to the disc 202A in conjunction with a movement such as rotation. Thereby, scratches on the surface of the disk 202A, occurrence of contamination, and the like can be suppressed.

Moreover, when the bolt 203 is completely tightened, the large diameter portion of the bolt 203 is accommodated in the bolt recess 211C of the disc spring 210, so that the space for the tightening structure 200 can be saved. Since the disc spring 210 has a main body 211 having a shape corresponding to the shape of the bolt 203, the spacer 201A, and the hub 201B, further space saving of the tightening structure 200 can be achieved.

(3) Modification Although the present invention has been described using the above embodiment, the present invention is not limited to the above embodiment, and the above embodiment is within the scope of the present invention with respect to the configuration and shape of each member. Various modifications are possible.

For example, in the first embodiment, the flat surface 113B is formed by decreasing the plate thickness from the inner peripheral end 113C toward the outer peripheral end 113D. Is not limited to this embodiment. For example, in the disc spring 110A shown in FIG. 6, the flat surface 113B can be formed by bending the boundary portion between the inner peripheral side end portion 113C and the inclined surface 113A. In this case, the convex surface 112P is parallel to the concave surface 113, for example, in the axial cross section. In this aspect, for example, the flat surface 113B can be obtained by bending, and the cost can be reduced as compared with the case where polishing or the like is used. Therefore, the cost of the fastening structure 100 can be reduced.

Further, for example, in the second embodiment, the disc spring 210 having the main body 211 having a shape corresponding to the shape of the bolt 203, the spacer 201A, and the hub 201B is used. As long as the flat surface 213B of 213 can be brought into surface contact with the mating member when an impact occurs, the disc spring can have various shapes that can correspond to the shape of the mating member on which the disc spring is disposed. For example, the disc spring 210A shown in FIG. 7 has a convex surface 212P and a concave surface 213P that are multi-staged in the cross section in the axial direction. In this aspect, the space for the tightening structure 200 can be further reduced.

In addition, it goes without saying that the first and second embodiments and their modifications may be combined as appropriate.

Claims

A clamping member for pressing the pressed member is interposed between the clamping member and the pressed member, and the clamped member presses and holds the pressed member against the support member by clamping the clamping member. In the attached structure,
A disc spring is used as the clamp member,
The disc spring is formed on the outer peripheral end side of the concave surface, and has a flat surface that is inclined with respect to one surface on the inner peripheral side of the concave surface,
The disc spring is disposed such that a concave surface faces the pressed member and a convex surface faces the fastening member,
The tightening structure, wherein the deflection amount of the disc spring is set so that the support point of the concave surface is located on the inner peripheral side end portion of the flat surface or on the inner peripheral side thereof.
2. The tightening structure according to claim 1, wherein the flat surface of the disc spring is formed by decreasing the plate thickness from the inner peripheral side toward the outer peripheral side.
2. The tightening structure according to claim 1, wherein the flat surface of the disc spring is formed by bending a boundary portion between the inner peripheral side end portion and a portion adjacent thereto.
The tightening structure according to any one of claims 1 to 3, wherein the disc spring has a recess for accommodating a top portion of the tightening member.
The tightening structure according to any one of claims 1 to 4, wherein the disc spring has a multi-stage shape in an axial cross section.
A clamping member for pressing the pressed member is interposed between the clamping member and the pressed member, and the clamped member presses and holds the pressed member against the support member by clamping the clamping member. In the attached method,
As the clamp member, a disc spring having a flat surface that is formed on the outer peripheral end side of the concave surface and is inclined with respect to one surface on the inner peripheral side of the concave surface,
At the start of tightening of the tightening member, the outer peripheral end of the flat surface of the concave surface of the disc spring is brought into contact with the pressed member, and the inner peripheral end of the convex surface of the disc spring is tightened. Abut against the member,
When the tightening of the tightening member is completed, the amount of deflection of the disc spring is set so that the support point of the concave surface of the disc spring is located on the inner peripheral end of the flat surface or on the inner peripheral side thereof. A tightening method characterized by:
As the disc spring, a disc spring having a positioning hole is used,
As the support member, a support member in which a positioning recess is formed,
Prior to tightening of the tightening member, a positioning member is engaged with the positioning recess of the support member through the positioning hole of the disc spring,
The fastening method according to claim 6, wherein after the fastening of the fastening member is completed, the positioning member is removed from the positioning recess and the positioning hole.