JP3946752B1 - Locking nut - Google Patents

Abstract

An object of the present invention is to provide a locking nut that makes it possible to select an optimal material for an elastic member by making a nut body and an elastic member separate, and to realize a stable behavior of the elastic member. To do.
A nut body 11 and an elastic member 21 are provided. The elastic member 21 includes a wire portion 22 formed from a wire that is elastically deformed, and a fixing portion 23 provided on the proximal end side of the wire portion 22. The fixing portion 23 is fixed to the axial end surface 15 of the nut main body 11, and the wire portion 22 is arranged along the substantially circumferential direction of the screw hole 13 of the nut main body 11. The wire portion 22 is deflected in the radially inward direction of the nut main body from the base end 24 toward the tip 25, and when the bolt 31 is screwed, the wire portion 22 comes into contact with the bolt shaft portion, and the wire portion 22 Is elastically deformed radially outward to prevent the bolt 31 from loosening.
[Selection] Figure 1

Description

  The present invention relates to a locking nut.

Conventionally, a nut body provided with a screw hole and an elastic portion provided on the end surface of the nut body, and the elastic portion urges a bolt that is screwed into the nut body, thereby preventing loosening. Various proposals have been made for nuts. These conventional locking nuts are provided with an elastic part integrally formed with the nut body (Patent Document 1) and with an elastic part formed separately from the nut body (Patent Document 2). It can be divided roughly.
In the former (patent document 1), since the elastic part and the nut body are integrated, the material of the elastic part is subjected to a large spring elasticity in order to be restricted by the material in satisfying the function of the nut. There is a problem that it cannot be used and it is difficult to process the elastic portion.

  In the latter (Patent Document 2), since the elastic part and the nut body are separate, the elastic part can be formed of a separate material from the nut body, and the optimal material for the elastic part is selected. In addition, there is a feature that the processing of the elastic portion is relatively easy. As represented by Patent Document 2, an example in which a leaf spring is used for the elastic portion is common. More specifically, by projecting the tip of the leaf spring into the screw hole of the nut body and engaging the leaf spring with the screw thread of the bolt, the bolt acts elastically in the axial direction to prevent loosening of the screw. It is what you make.

  However, when trying to loosen the nut by inspection or the like, the leaf spring may reverse and lock the thread completely. Specifically, the leaf spring protruding in the screw hole is deformed along the flank on the advancing side of the screw thread as the bolt is screwed into the nut body, but all surfaces in the circumferential direction of the leaf spring are advanced. It is not in close contact with the side flank, but is deformed with some bending, and in some cases, the tip of the leaf spring is stuck in the thread. In such a state, if the bolt is rotated in the loosening direction, the leaf spring is bent and reversed, and the screw thread is locked, making it difficult to loosen the bolt.

JP-A-11-247824 Registered Utility Model No. 3102501

  The present invention includes a nut main body having a screw hole and an elastic member provided on the end surface of the nut main body, and the elastic member biases a bolt that is screwed into the nut main body, thereby preventing slack. In the retaining nut, by making the nut body and the elastic member separate, it is possible to select the most suitable material for the elastic member, and reversing the leaf spring when a leaf spring is used for the elastic member, etc. An object of the present invention is to provide a locking nut that can prevent adverse effects caused by the unexpected behavior.

The invention according to claim 1 of the present application includes a nut main body having a screw hole and an elastic member provided on the end surface of the nut main body, and the elastic member biases a bolt screwed into the nut main body. , the locking nut that forms a locking, to adopt the ones that take the following configuration.
That is, the elastic member is a separate member from the nut body. The elastic member includes a wire portion that is elastically deformed by screwing the nut body and the bolt, and a fixing portion that is provided on the base end side of the wire portion. In the cross section along the direction perpendicular to the longitudinal direction of the wire portion, the ratio of thickness to width is in the range of 1 to 6 to 6 to 1. The wire portion is arranged along the substantially circumferential direction of the screw hole, with the other end of the wire portion as a free end with respect to the fixed portion on the base end side, with the circumferential direction of the screw hole of the nut body as the longitudinal direction, The inner diameter on the fixed part side is equal to or larger than the root diameter of the female thread of the nut body, and has a portion whose inner diameter is smaller than the root diameter of the female thread of the nut body on the tip side of the fixed part. By elastic deformation, the nut body is arranged so that it can be displaced in the axial direction of the nut and can be displaced in the radially outward direction. When the bolt is screwed, the wire portion abuts on the bolt shaft portion, and the bolt is prevented from loosening by elastic deformation in the axial direction and the radially outward direction. The wire portion includes an abutting portion on the inner peripheral surface, and this abutting portion abuts on the advance side flank of the bolt thread, and the wire portion does not contact the follower flank of the bolt.
In the invention according to claim 2 of the present application, the wire portion is arranged so that it can be displaced in the axial direction of the nut and in the radially outward direction with respect to the nut body by elastic deformation, and the bolt is screwed together. 2. The slack stop according to claim 1, wherein the wire portion abuts against the bolt shaft portion to prevent the bolt from loosening by the elastic deformation in the axial direction and the radially outward direction. Provide nuts.
The invention according to claim 3 of the present application is such that the fixed portion and the wire portion are formed of one wire, and the fixed portion extends in the circumferential direction outside the screw hole and is connected to the end surface of the nut body. The loosening prevention nut according to claim 1, which is fixed by spot welding.
In the invention according to claim 4 of the present application, the lead angle of the wire portion is equal to or smaller than the lead angle of the female screw of the screw hole. The described locking nut is provided.
In the invention concerning Claim 5 of this application, an elastic member is formed with spring steel , The loosening prevention nut in any one of Claim 1 thru | or 3 characterized by the above-mentioned is provided.
The invention according to claim 6 of the present application provides the loosening prevention nut according to any one of claims 1 to 3, wherein the inner peripheral surface of the wire portion is formed into a rough surface.

In the locking nut according to the first and second aspects of the present invention, the wire portion is arranged along the substantially circumferential direction of the screw hole of the nut body, and the inner diameter of the nut body is closer to the distal end than the fixed portion. The screw has a portion smaller than the root diameter of the female screw, and when the bolt is screwed, the wire portion comes into contact with the bolt shaft portion, and the wire portion elastically deforms radially outward, thereby preventing the bolt from loosening. Can be made. Moreover, since the elastically deforming portion is a wire portion, it does not reverse like a leaf spring, exhibits a stable behavior, and exhibits a stable loosening prevention effect. That is, the ratio of the thickness (axial length) and width (length in the direction orthogonal to the axial direction) is 1 to 6 to 6: 1 in the cross section along the direction orthogonal to the longitudinal direction of the wire portion. It is within the range, and there is no fear of inversion like a leaf spring, and it shows a stable behavior.
In particular, the wire portion has an abutting portion on the inner peripheral surface, and this abutting portion abuts only on the advancing flank of the thread of the bolt, so that the urging force of the elastic member acts as an axial force. Thus, it has been possible to provide a locking nut that provides a good locking.
In the invention according to claim 3 of the present application, since the fixed portion and the wire portion are formed of one wire, it can be manufactured at a low cost, and is fixed to the end surface of the nut body by spot welding. Therefore, it has been possible to provide a locking nut that can be easily manufactured at low cost. In particular, the elastic member composed of the fixing portion and the wire portion is a separate member from the nut body, and is fixed to the nut body by spot welding the separate member. A material different from that of the nut body can be adopted for the member.
For example, when a member composed of such a fixed portion and a wire portion is to be formed integrally with the nut body, both are composed of the same material. Since spring steel is not suitable as a material for the nut body, such spring steel cannot be employed, and a material suitable for causing the elastic member to function as an elastic member cannot be employed. In this regard, in the above-described invention of the present application, by making the elastic member separate from the nut main body, the nut main body is made of a material suitable for the nut as usual, and the elastic member is provided with elasticity such as spring steel. A material suitable as a member can be employed. In addition, when the elastic member is integrated with the nut body, the formation of the wire portion becomes extremely difficult. However, by forming the nut body and the wire portion (elastic member) separately and joining them by welding, Can be manufactured.
In the invention according to claim 4 of the present application, in particular, the lead angle of the wire portion is equal to the lead angle of the female screw of the screw hole or smaller than the lead angle of the female screw of the screw hole. Does not add elasticity.
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In the invention according to claim 6 of the present application, since the inner peripheral surface of the wire portion is formed to be a rough surface, it is possible to provide a locking nut that acts as a resistance well.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1A and 1B show a locking nut according to an embodiment of the present invention. FIG. 1A is a front view, FIG. 1B is a plan view, FIG. 1C is a sectional view of an elastic body of the nut, and FIG. It is a front view which shows the example of a change of the nut. FIG. 2 is an explanatory view showing a state in which the locking nut is screwed onto the bolt. FIG. 3 is an enlarged view of a main part of the nut.

  The nut 10 according to this embodiment includes a nut body 11 and an elastic member 21. The nut body 11 is substantially the same as a conventionally known metal nut, and includes a tool engaging portion 12 represented by a hexagonal shape on the outer peripheral surface, and a screw hole 13 is provided in the center. A female screw 14 is formed in the screw hole 13. As shown in FIG. 2, the female screw 14 is screwed with a male screw 32 of a bolt 31. One of the end surfaces in the axial direction of the nut body 11 is a seating surface 15 and the other is an open end surface 16 (FIG. 1). The elastic member 21 may be provided on the seat surface 15, but is usually provided on the open end surface 16 on the opposite side of the seat surface 15.

Next, as shown in FIGS. 1A to 1C, the elastic member 21 includes a wire portion 22 and a fixing portion 23. The wire portion 22 is a portion that is elastically deformed by screwing with the bolt 31, and the fixing portion 23 is provided on the proximal end side of the wire portion 22, and fixes the entire elastic member 21 to the open end surface 16 of the nut body 11. In this example, the elastic member 21 is entirely formed of a material having elasticity, such as spring steel. However, depending on the case, the wire member 22 and the fixed part may be used only for the wire member 22, for example. 23 can be formed of a different material.
As shown in FIG. 1A, in this embodiment, the entire elastic member 21 is constituted by a single wire. This wire has elasticity and is formed into a semicircular arc shape by bending. The wire is fixed to the nut main body 11 (open end surface) with a predetermined range to be described later from one end of the wire as a fixed portion 23, and the other end side of the wire is elastic as a free end. Due to the deformation, the nut body 11 is arranged so as to be movable with respect to the open end face 16, that is, the other end portion can be displaced relative to the open end face 16 of the nut body 11 in the axial direction (of the nut). Hereinafter, the configuration of each part of the elastic member 21 will be described in more detail.

  In this example, the fixing portion 23 has a semicircular shape formed substantially concentrically with the screw hole 13 and has an inner diameter equal to or larger than the valley diameter of the female screw 14. In other words, the fixing portion 23 may be provided at a size and a position that do not engage with the male screw 32 of the bolt 31. The fixing portion 23 is fixed to the open end surface 16 of the nut body 11 by welding, particularly preferably spot welding. In FIG. 1C, S indicates a spot welding position. This fixing is not limited to welding, but can be carried out by appropriately changing to a fixing method such as providing a claw or the like on the nut body 11 and fixing the fixing portion 23 by caulking, but on the nut 10 side. It is advantageous to employ welding, particularly spot welding, in that no special processing is required, and it can be easily used as a loosening prevention nut 10 by welding the elastic member 21 to a ready-made nut. This is extremely advantageous in that it can be performed. The cross-sectional shape of the fixing portion 23 can be changed as appropriate, such as a circle or a rectangle. However, in order to increase the contact area with the open end surface 16, the portion in contact with the open end surface 16 may be flat. This is desirable in terms of increasing the certainty of fixation.

  Further, in this example, the fixing portion 23 is implemented as a semicircular shape, but may be any length as long as it can be reliably fixed by welding, and can be appropriately changed to a circular arc shape such as a quarter arc. Alternatively, it may be an appropriate linear shape such as a linear shape or an indeterminate curved bent shape. Furthermore, although it may have a larger width than the wire portion 22 such as a rectangular shape or a circular shape in plan view, it is more advantageous in terms of processing and raw material costs to form the elastic member 21 with a series of wire portions. As for 23, a linear one is also advantageous. In addition, as shown in FIG. 5, it is also possible to form and fix the fixing | fixed part 23 so that the outer peripheral part along the external shape (in this case hexagon) of the nut 10 may be provided.

  Next, the wire portion 22 will be described. While the fixing portion 23 is fixed to the nut main body 11, the wire portion 22 is arranged to be movable with respect to the open end surface 16 of the nut main body 11. The wire portion 22 has a substantially arc shape in plan view, and is arranged along the substantially circumferential direction of the screw hole 13 of the nut body 11, but the radially inward direction of the nut body 11 from the proximal end side 24 toward the distal end side 25. It is deflected in the (radial center direction). More specifically, the inner diameter of the wire portion 22 on the proximal end side 24 is equal to or larger than the root diameter of the female screw 14 of the nut body 11, but the inner diameter gradually decreases, and the inner diameter on the distal end side 25 is the nut body. 11 is smaller than the root diameter of the female thread 14. Thereby, when the bolt 31 is screwed together, the wire portion 22 contacts the male screw 32, and the wire portion 22 is elastically deformed in the radially outward direction. As a result, a force in a substantially central axis direction (inward radial direction) is applied to the bolt 31, and the bolt 31 can be prevented from loosening. As shown in FIG. 1C, the minimum inner diameter of the wire portion 22 can be made smaller than the crest diameter of the female screw 14, and the minimum inner diameter is determined by the biasing force necessary for preventing loosening, the material of the wire portion 22, Various changes can be made in consideration of the thickness, length, and the like of the wire portion 22. In this example, the minimum inner diameter is the leading edge of the wire portion 22, but may be a position closer to the distal end than the proximal end side 24, and may be a shape in which the leading edge is curved in the radially outward direction.

  In this example, the wire portion 22 has a length in the circumferential direction that is about a half of the screw hole 13, but when the bolt 31 is screwed, the wire portion 22 is elastically deformed radially outward and the bolt 31 is loosened. For example, the periphery of the screw hole 13 may be made ¼ to ¾. The length of the wire portion 22 may be appropriately set by taking into account the urging force necessary for preventing loosening, the material of the wire portion 22, the thickness of the wire portion 22, and the like. Although it is desirable that the base end side 24 of the wire portion 22 is disposed on the extension of the female screw 14 in terms of facilitating the engagement of the male screw 32 of the bolt 31, the position thereof is the position of the male screw 32 of the bolt 31. It can be appropriately changed within a range where the engagement is possible.

  In this example, the wire portion 22 gradually moves away from the open end face 16 in the axial direction as it goes from the proximal end side 24 toward the distal end side 25 as shown in FIG. More specifically, in this example, the wire portion 22 has a lead angle equal to the lead angle of the female screw 14 of the screw hole 13. The lead angle may be 0 degrees as shown in FIG. 1D, but is preferably not larger than the lead angle of the female screw 14. This is because if the lead angle is larger than the lead angle of the female screw 14, the looseness direction elasticity is applied to the bolt 31 when the bolt 31 is screwed. On the contrary, by making it smaller than the lead angle of the female screw 14, axial elasticity is applied to the bolt 31, and it is possible to prevent looseness along with the radial elasticity.

As shown in FIG. 2, the wire portion 22 contacts the bolt 31 on the arc-shaped inner peripheral side. The shape of the inner peripheral surface of the wire portion 22 will be described. An abutting portion 26 is provided on the advancing side of the screw in the axial direction, and the abutting portion 26 forms a trough between screw threads of the bolt 31. Abut. The contact portion 26 may be in contact with the advancing flank 33 by a surface, may be in contact with a line, or may be in contact with a point .

Specifically, as shown in FIG. 3, the urging force is applied as an axial force to increase the fastening force of the screw, thereby preventing loosening. In this example, only one contact portion 26 is formed on the inner peripheral surface. Then, the abutting portion 26 abuts only on the advance side flank 33 of the bolt 31 (so as not to contact the follower side flank 34). As a result, the urging force in the direction orthogonal to the axial direction is distributed in the axial direction according to the flank angle of the advancing flank 33 and acts as an axial force that serves as a screw fastening force. Demonstrate. Also in this example, the abutting portion 26 and the advancing flank 33 may be in contact with a line, in addition to being in contact with a surface, or in contact with a point.

In each of the above examples, the ratio of the thickness (axial length) to the width (length in the direction perpendicular to the axial direction) is 1 to 6 in the cross section along the direction perpendicular to the longitudinal direction. It is in the range of ˜6: 1, and shows a stable behavior without the possibility of inversion like a leaf spring. The range of the ratio is more preferably 1 to 3 to 1. In addition, the member which can form a coil by a bending process is suitable for a wire.
Further, as described above, as a member of the nut body and another body, at the wire, the main portion or the wire portion 22 of the elastic member 21, by forming, during manufacture, with a larger wire portion 22 of the cross-sectional area It is possible to easily select the elastic member 21. Thus, by adopting a large cross-sectional area in the direction crossing the direction in which the wire extends, the wire portion 22 can be easily changed to one having strong elasticity (strong waist), as necessary. The effect of greater locking can be expected.
In each of the above embodiments, the bolt 31 has been described on the assumption that a general bolt shown in FIG. In addition, as shown to FIG. 4 (A)-(C), it can implement as what forms the engaging part 37 with respect to the formulation part 22 in the external thread 32 as the volt | bolt 31. FIG. 4A is an overall side view of the bolt 31, and FIG. 4B is a schematic sectional view showing a state where the nut shown in FIG. 1C and the bolt 31 are screwed together. (C) is an enlarged sectional view of the bolt 31. The engagement portion 37 is provided with three maximum diameter portions 35 and a minimum diameter portion 36 at intervals with respect to the male screw 32 in the circumferential direction, and gradually increases from one maximum diameter portion 35 to the base of the adjacent maximum diameter portion 35. The outer diameter is reduced, and the base portion of the adjacent maximum diameter portion 35 is the minimum diameter portion 36. By forming in this way, a step is generated between the maximum diameter portion 35 and the minimum guard portion provided on the base portion 36, and the step is used as the engagement portion 37 as shown in FIG. When the nut is screwed, it can be brought into contact with the tip surface of the wire portion 22 and hooked so that the nut cannot be returned, and the rotation stopper can be made more reliable. In this embodiment, three engaging portions 37 are shown. However, the number of engaging portions 37 may be less than three, such as one or two, or four or more.

1 shows a locking nut according to an embodiment of the present invention, in which (A) is a front view, (B) is a sectional view of an elastic body of the nut, (C) is a plan view, and (D) is a nut of the nut. It is a front view which shows the example of a change. It is explanatory drawing of the state which screwed the loosening prevention nut to the volt | bolt. It is a principal part enlarged view of the nut . (A) is a side view showing another form of a bolt suitable for use in the nut, (B) is a schematic cross-sectional view showing a state in which the bolt is screwed to the nut, (C) Is an enlarged cross-sectional view of the bolt. It is a top view which shows other embodiment of the elastic member of the said nut.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Nut 11 Nut main body 12 Tool engaging part 13 Screw hole 14 Female screw 15 Seat surface 16 Open end surface 21 Elastic member 22 Wire part 23 Fixing part 24 Base end side 25 Front end side 26 Contact part 31 Bolt 32 Male thread 33 Advance side flank 34 Tracking flank s Spot welding position

Claims (6)

A nut body having a threaded hole, and an elastic member provided on the nut body end face, by energizing the bolt the elastic member is screwed into the nut body, the locking nut forms a locking,
The elastic member is a separate member from the nut body,
The elastic member includes a wire portion that is elastically deformed by screwing the nut body and the bolt, and a fixing portion that is provided on the base end side of the wire portion,
In the cross section along the direction perpendicular to the longitudinal direction of the wire portion, the ratio of thickness to width is in the range of 1 to 6 to 6 to 1,
The wire portion is arranged along the substantially circumferential direction of the screw hole, with the other end of the wire portion as a free end with respect to the fixed portion on the base end side, with the circumferential direction of the screw hole of the nut body as the longitudinal direction, The inner diameter on the fixed part side is equal to or larger than the root diameter of the female thread of the nut body, and has a portion whose inner diameter is smaller than the root diameter of the female thread of the nut body on the tip side of the fixed part. Due to elastic deformation, the nut body is arranged so that it can be displaced in the radially outward direction of the nut,
When the bolt is screwed, the wire section, the bolt shaft portion abuts, by the elastic deformation of the above-mentioned radially outward direction, which forms a locking bolt,
The wire part comprises a contact portion on the inner peripheral surface, that the contact portion, the bolt thread of stabbing flank abuts, the wire section, and pursued flank of the bolt, but not in contact Anti-loosening nut characterized by The wire portion is arranged so that it can be displaced in the axial direction of the nut and can be displaced in the radially outward direction with respect to the nut body by elastic deformation,
The wire rod portion abuts on the bolt shaft portion when the bolt is screwed together, and the bolt is prevented from loosening by elastic deformation in the axial direction and the radially outward direction. The described locking nut. The fixed part and the wire part are formed by one wire,
The loosening prevention nut according to claim 1 or 2, wherein the fixing portion extends to the outside of the screw hole in the circumferential direction and is fixed to the end face of the nut body by spot welding. 4. The loosening prevention nut according to claim 1 , wherein the lead angle of the wire portion is equal to or smaller than the lead angle of the female screw of the screw hole . The loosening prevention nut according to any one of claims 1 to 4 , wherein the elastic member is formed of spring steel .   The loosening prevention nut according to any one of claims 1 to 4, wherein an inner peripheral surface of the wire portion is formed into a rough surface.

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