JPH0596531U - Lock nut - Google Patents

Abstract

(57) [Summary] [Structure] A metal plate is provided in the resin tightening body 1 having a female screw hole. The locking plate portion 4 is projected from the inner circumference of the metal plate toward the center of the female screw hole, and the locking plate portion is inclined with respect to the center. When the tightening body is tightened, the resin portion inside the metal plate is pressed by the locking plate portion of the metal plate and elastically deformed, the contact pressure between the resin portion and the male screw 13a increases, and the frictional resistance also increases. Therefore, this frictional force is added in addition to the original function of preventing the locking plate portion from acting on the male screw. When the resin portion inside the metal plate is pressed in the radial direction, a compressive stress is generated in the circumferential direction, and the tensile stress in the circumferential direction generated by tightening the tightening body 1 and this compressive stress cancel each other out. The stress in the tightened body is relieved. The corner portions of the hexagonal portion 7 of the tightening body are reinforced by the plate portions 4 and 5 of the metal plate. [Effect] The strength of the tightening body 1 is increased. The locking plate portion 4 enhances the anti-loosening effect and suppresses the destruction due to the occurrence of solvent cracks and the like.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to a nut provided with a metal plate for locking in a resin tightening body.

[0002]

[Problems to be solved by conventional techniques and devices]

 Conventionally, there are nuts made of resin for the purpose of weight reduction and the like. However, since the strength of such a resin nut is lower than that of a metal nut, the height of the nut must be considerably increased. Further, when the resin nut is screwed into the male screw and a force is exerted to spread it in the radial direction, a tensile stress is generated in the circumferential direction by the force. Therefore, when the resin nut comes into contact with a highly permeable liquid, this tensile stress easily causes solvent cracks, which may cause destruction.

Therefore, the present invention is to solve the above problems by providing a metal plate for preventing loosening in the resin nut and improving the shape of the metal plate.

[0004]

[Means for Solving the Problems]

 As shown in the drawings of each embodiment described later, in the locking nut N according to the present invention, a metal plate 2 is provided in the outer periphery of the female screw hole 9 in the resin tightening body 1 having the female screw hole 9. The male screw 13a is screwed into the female screw 9a of the female screw hole 9. A pressure contact portion 4a engaged with the male screw 13a is provided on the inner periphery of the metal plate 2 so as to be exposed in the female screw hole 9.

A locking plate portion 4 is provided so as to project from the inner periphery of the metal plate 2 toward the center C of the female screw hole 9, and the locking plate portion 4 is inclined with respect to the center C. The tightening body 1 has a hexagonal portion 7, and plate portions 4 and 5 located at the corner portions 7a are provided on the metal plate 2.

[0006]

[Action]

 The metal plate 2 in the resin tightening body 1 enhances the strength of the tightening body 1. When the tightening body 1 is screwed into the male screw 13a and tightened, the locking plate portion 4 of the metal plate 2 presses the resin portion inside and elastically deforms, and the contact between this resin portion and the male screw 13a. The pressure increases and the frictional resistance also increases. In other words, there is a synergistic effect that the frictional force increases with tightening. Therefore, this frictional force is added in addition to the original function of preventing the pressure contact portion 4a of the locking plate portion 4 from acting on the male screw 13a.

Further, as described above, when the resin portion inside the metal plate 2 is pressed in the radial direction, a compressive stress is generated in the circumferential direction, and the tensile force in the circumferential direction is generated by tightening the tightening body 1. The stress and this compressive stress cancel each other out to relax the stress in the tightening body 1.

Further, the corner portion 7 a of the hexagonal portion 7 of the tightening body 1 is reinforced by the plate portions 4 and 5 of the metal plate 2.

[0009]

First Embodiment First, a locking nut according to a first embodiment of the present invention will be described with reference to FIGS.

As shown in FIGS. 1 and 2, the loosening prevention nut N includes a resin tightening body 1 and a metal plate 2. In the metal plate 2, three locking plate portions 4 and three reinforcing plate portions 5 are alternately projected toward the center C at six equally divided positions on the inner circumference of the annular portion 3. Each locking plate portion 4 is extended on one side of the annular portion 3 in a direction inclined with respect to the center C, and a pressing portion 4a is formed at the tip thereof. In each reinforcing plate portion 5, a base plate portion 5a extends from the annular portion 3 in a direction orthogonal to the center C, and a rising portion 5b extends from the tip end of the base plate portion 5a to each locking plate portion. Adjacent to No. 4 and extending in the direction along the center C. An insertion hole 6 is formed on the center C of the metal plate 2, and the insertion hole 6 is continuous with the space between the plate portions 4 and 5.

The resin tightening body 1 has a hexagonal portion 7 and a flange portion 8, and a female screw hole 9 is formed on the center C of the hexagonal portion 7. On the outer periphery of the female screw hole 9, a fitting hole 10 into which the locking plate portions 4 are fitted and a fitting hole 11 into which the reinforcing plate portions 5 are fitted into the tightening body 1 are continuous with each other. The fitting holes 10 and 11 are formed and are open to the flange portion 8 side. Three notches 12 are formed in the inner circumference of the female screw hole 9 on the hexagonal portion 7 opposite to the flange portion 8, and each notch 12 is continuous with the one fitting hole 10 1.

As shown in FIGS. 3 and 4, the metal plate 2 is fitted into the tightening body 1 from the flange portion 8 side, and the metal plate 2 is fitted into the fitting holes 10 and 11 of the tightening body 1. The locking plate portions 4 and the reinforcing plate portions 5 are aligned with each other, and the annular portion 3 of the metal plate 2 is aligned with the inside of the flange portion 8 of the tightening body 1 and is exposed to the outside. Each locking plate portion 4 and each reinforcing plate portion 5 are located inside each corner portion 7a of the hexagonal portion 7. The pressure contact portion 4 a of each locking plate portion 4 is exposed at each notch 12 of the female screw hole 9.

In the locking nut thus constructed, the bolt 13 is screwed into the female screw hole 9 of the tightening body 1, and the female screw 9a and the male screw 13a are meshed with each other. In this screwed state, the pressure contact portion 4a of the metal plate 2 is engaged with the valley portion of the male screw portion 13a.

In such a locking nut N, the strength increases because the metal plate 2 is inside the resin tightening body 1. Moreover, since the metal plate 2 covers the fastening body 1, the fastening body 1 suppresses the local deformation of the metal plate 2 and the strength is further increased. Therefore, the height of the nut N can be reduced.

When the locking nut N is tightened to the bolt 13, the resin portion of the tightening body 1 inside the metal plate 2 is pressed and elastically deformed, and the contact pressure between the resin portion and the male screw 13a rises. And the frictional resistance also increases. In other words, the synergistic effect that the frictional force increases with tightening is generated. Therefore, this frictional force is added in addition to the original function of preventing loosening that acts between the pressure contact portion 4a of each locking plate portion 4 and the male screw 13a, and the loosening prevention effect is reliably exhibited.

As described above, since the resin portion inside the metal plate 2 is pressed in the radial direction and a compressive stress is generated in the circumferential direction, as described in the prior art, the screwing of the male screw 13a causes the peripheral portion to be wound. The tensile stress generated in the direction and the compressive stress cancel each other out, and it is possible to suppress the fracture due to the occurrence of solvent cracks. Further, since the metal plate 2 is locked to the male screw 13a, it plays a role of preventing the fastening state from immediately breaking even if it is broken, which is more safe.

Further, since each locking plate portion 4 and each reinforcing plate portion 5 of the metal plate 2 are located at the corner portion 7a of the hexagonal portion 7 of the tightening body 1, the strength of the corner portion 7a is improved. The corner portion 7a is less likely to be crushed during the fastening work.

[0018]

Second Embodiment In the second embodiment shown in FIGS. 5 to 8, as compared with the first embodiment, each reinforcing plate portion 5 is omitted and only three locking plate portions 4 are provided. It is formed on the metal plate 2. Only the fitting hole 10 is formed in the tightening body 1 so as to match each locking plate portion 4. Also in this second embodiment, each locking plate portion 4 performs the same function as in the first embodiment, but each locking plate portion 4 is located only in a part of each corner portion 7a of the hexagonal portion 7. Therefore, the strength of the corner portion 7a is inferior to that of the first embodiment.

[0019]

Third Embodiment In the third embodiment shown in FIGS. 9 to 12, the shape of the metal plate 2 is the same as that in the first embodiment, but this metal plate 2 forms the tightening body 1. Sometimes they are inserted and they are integrated. Therefore, the fitting holes 10 and 11 and the notch 12 in the first embodiment are omitted, the press contact portion 4a of each locking plate portion 4 is exposed to the female screw 9a of the female screw hole 9, and the ring of the metal plate 2 is The portion 3 is exposed from the flange portion 8 of the tightening body 1.

[0020]

[Other Examples]

 In the fourth embodiment shown in FIGS. 13 to 16, the fifth embodiment shown in FIGS. 17 to 20 and the sixth embodiment shown in FIGS. 21 to 24, the metal plate 2 is inside the tightening body 1. It is similar to the third embodiment in that it is insert-molded. However, the shapes of the metal plates 2 are different from each other, and the reinforcing plate portions 5 in the third embodiment are omitted and the six locking plate portions 4 are formed. In addition, in the fourth to sixth embodiments, the annular portion 3 of the metal plate 2 is not exposed from the flange portion 8 of the tightening body 1. Each locking plate portion 4 is located at each corner portion 7a of the hexagonal portion 7, and this corner portion 7a is strengthened as in the case of the third embodiment. Moreover, since there are six locking plate portions 4, the loosening prevention effect is higher than in the case of the third embodiment.

[0021]

[Effect of the device]

 According to the locking nut N of the present invention, the strength of the metal plate 2 in the resin tightening body 1 is increased and the height of the nut N can be reduced. Further, the locking plate portion 4 having a predetermined shape formed on the metal plate 2 enhances the loosening prevention effect and suppresses the destruction due to the occurrence of solvent cracks and the like.

[Brief description of drawings]

FIG. 1 is a plan view showing a metal plate of a locking nut according to a first embodiment.

FIG. 2 is a front view or a front cross-sectional view showing the metal plate and the tightening body of the locking nut separately from each other.

FIG. 3 (a) is a plan view of a locking nut showing a state where the metal plate is assembled to a tightening body, and FIG. 3 (b) is a bottom view of the same.

FIG. 4 is a front cross-sectional view showing a state in which the locking nut is screwed into a bolt.

FIG. 5 is a plan view showing a metal plate of a locking nut according to a second embodiment.

FIG. 6 is a front view or a front cross-sectional view showing the metal plate and the tightening body separated from each other in the locking nut.

FIG. 7 (a) is a plan view of a locking nut showing a state where the metal plate is assembled to a tightening body, and FIG. 7 (b) is a bottom view of the same.

FIG. 8 is a front cross-sectional view showing a state where the locking nut is screwed into a bolt.

FIG. 9 is a plan view showing a metal plate of the locking nut according to the third embodiment.

FIG. 10 is a front view of the same.

FIG. 11 is a front cross-sectional view showing a state in which a metal plate is insert-molded into a tightening body in the lock nut, and the nut is screwed into a bolt.

FIG. 12 (a) is a plan view showing this locking nut, and FIG. 12 (b) is a bottom view of the same.

FIG. 13 is a plan view showing a metal plate of the locking nut according to the fourth embodiment.

FIG. 14 is a front view of the same.

FIG. 15 is a front sectional view showing a state in which a metal plate is insert-molded into a tightening body in the locking nut, and the nut is screwed into a bolt.

FIG. 16A is a plan view showing the locking nut, and FIG. 16B is a bottom view of the same.

FIG. 17 is a plan view showing a metal plate of the locking nut according to the fifth embodiment.

FIG. 18 is a front view of the same.

FIG. 19 is a front sectional view showing a state in which a metal plate is insert-molded into a tightening body in the locking nut, and the nut is screwed into a bolt.

20A is a plan view showing the locking nut, and FIG. 20B is a bottom view of the same.

FIG. 21 is a plan view showing a metal plate of the locking nut according to the sixth embodiment.

FIG. 22 is a front view of the same.

FIG. 23 is a front cross-sectional view showing a state in which a metal plate is insert-molded into a tightening body in the lock nut, and the nut is screwed into a bolt.

FIG. 24 (a) is a plan view showing the locking nut, and FIG. 24 (b) is a bottom view of the same.

[Explanation of symbols]

1 tightening body, 2 metal plate, 3 annular part, 4 locking plate part,
4a Pressure contact part, 5 Reinforcement plate part, 6 Insertion hole, 7 Hexagonal part, 7a Corner part, 8 Flange part, 9 Female screw hole, 9a
Female screw, 10 fitting hole, 11 fitting hole, 12 notch, 13 bolt, 13a male screw, C center.

Claims (2)

[Scope of utility model registration request] 1. A metal plate (2) is provided on the outer periphery of the female screw hole (9) in a resin tightening body (1) having the female screw hole (9), and the metal plate (2) is provided on the inner periphery of the metal plate (2). Is provided so as to expose the pressure contact portion (4a) locked to the male screw (13a) screwed to the female screw (9a) of the female screw hole (9) in the female screw hole (9). The locking plate (4) is projected from the inner periphery of the female screw hole (9) toward the center (C) of the female screw hole (9), and the tip of the locking plate (4) is projected. A lock nut, characterized in that the pressure contact portion (4a) is provided on the portion. 2. The plate portion (4, 5) of the metal plate (2) according to claim 1, wherein the plate portion (4, 5) is located in the corner portion (7a) of the hexagonal portion (7) provided in the tightening body (1). Locking nut that is characterized by.