JP2006226465A - Nut assembly, its manufacturing method and its forming die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nut assembly easy to manufacture, comprising a nut and a body having a non-screwed hole in which the nut is buried and which communicates with a nut hole of the nut, the non-screwed hole having an inner diameter smaller than the valley diameter of the screw hole. <P>SOLUTION: The nut assembly comprises the metal nut 2, an annular elastic member 4, and the body 5 into which the metal nut 2 and part of the elastic member 4 are buried and fixed. The elastic member 4 includes an exposed portion 31 protruded from the inner periphery of the non-screwed hole 20 and a contact portion 32 for encircling the peripheral edge of an opening 11 in a first end face 3 of the metal nut 2. A core pin for forming the non-screwed hole is inserted through the exposed portion 31 of the elastic member 4 to bring the outer periphery of the core pin in close contact with the inner periphery of the exposed portion 31. Thus, the elastic member 4 and the core pin are cooperated with each other to seal the opening 11 in the first end face 3 of the metal nut 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a nut assembly, a method of manufacturing a nut assembly, and a mold for molding the nut assembly.

A locking nut in which a metal nut is inserted into a resin member is known (for example, see Patent Document 1). The resin member is formed with a screwless hole having a smaller diameter than the screw hole of the metal nut. When the locking nut and the bolt are joined together, the bolt is screwed into the screw hole of the metal nut and inserted through the screwless hole of the resin member. Thus, the bolt is elastically tightened to the resin member so as not to loosen from the locking nut.
JP-A-6-308432

  Conventionally, it is required that such a nut can be easily manufactured. Accordingly, an object of the present invention is to provide a nut assembly, a method of manufacturing the nut assembly, and a mold for forming the nut assembly, in which labor required for manufacturing is reduced.

Usually, when a resin member having a screwless hole that embeds a nut and communicates with a screw hole of the nut is molded, a screwless hole forming pin is provided in a mold for molding the resin member. Then, a part of the pin is inserted into the nut and the nut is held by the pin, and the resin member is molded in this state.
Here, the inner diameter of the screwless hole is smaller than the inner diameter of the screw hole of the nut. That is, the outer diameter of the screwless hole forming pin is smaller than the inner diameter of the screw hole. Therefore, even when the pin is inserted into the screw hole to close the screw hole when the resin member is molded, the resin flows into the gap between the pin and the screw hole and adheres to the inner peripheral surface of the screw hole. For this reason, after molding the resin member, it is necessary to remove the resin adhering to the inner peripheral surface of the screw hole, which is troublesome.

  Accordingly, the invention described in claim 1 made by the present inventor includes a screw hole for screwing onto a screw shaft, a nut having first and second end faces through which the screw hole opens, and a first end face of the nut. An annular elastic member disposed adjacent to the main body, and a main body formed by embedding and fixing a part of the nut and the elastic member. A peripheral side portion surrounding the nut, a portion covering the first end surface of the nut, and a screwless hole formed in a portion covering the first end surface of the nut and continuing to the screw hole of the nut, and an inner diameter of the screwless hole Is smaller than the root diameter of the screw hole of the nut, and the elastic member includes an annular embedded part embedded in the main body along the inner periphery of the screwless hole, and a nut protruding from the inner periphery of the screwless hole. A concentric ring-shaped exposed part and a nut A nut assembly, characterized in that the comprise an annular contact portion which surrounds the periphery of the resilient contact states at the nut of the screw holes on the end face.

  According to the present invention, for example, by inserting a core pin for forming a screwless hole of the main body portion into the exposed portion of the elastic member, the outer periphery of the core pin and the inner periphery of the exposed portion are brought into close contact with each other. Can cooperate to seal the opening of the screw hole. Thereby, when a nut is inserted and a main-body part (unthreaded hole) is shape | molded, it can prevent that the material inject | poured in the metal mold | die for main-body-part shaping | molding penetrate | invades into the screw hole of a nut. As a result, it is possible to prevent the material for molding the main body from adhering to the inner peripheral surface of the screw hole, eliminating the need to remove the material adhering to the inner peripheral surface of the screw hole, which greatly reduces the labor involved in manufacturing. Can be reduced.

  According to a second aspect of the present invention, in the first aspect, the main body portion covers at least a part of the second end surface of the nut and receives a fastening target, and a screw hole of the nut formed in the seat portion. A large-diameter hole that is continuous with the inner diameter of the large-diameter hole is larger than the outer diameter of the screw shaft, and the nut is embedded in the seat portion of the main body portion and suppresses the expansion of the seat portion. The nut assembly further includes a protrusion.

  According to the present invention, for example, when a screw and a nut embedded body are coupled and a fastening object such as a plate material is fastened, the nut is moved to the fastening object side by screwing with the screw shaft of the screw and the seat portion is moved. By compressing and expanding the seat part (large diameter hole), it becomes easy to detach from the main body part. However, the expansion of the seat part can be suppressed by the expansion suppression protrusion, so the nut is detached from the main body part. This can be reliably suppressed.

  According to a third aspect of the present invention, there is provided a method of manufacturing the nut assembly according to the first or second aspect, wherein the nut and the elastic member are set in the cavity for molding the main body of the mold, A forming step of forming the main body, and in the preparation step, the contact portion of the elastic member is placed on the first end surface of the nut in a state where the elastic member is fitted to a part of the core pin for forming the screwless hole. A method of manufacturing a nut assembly characterized by being in contact.

  According to the present invention, the opening of the screw hole of the nut is sealed by a simple preparatory work of fitting the core pin for forming the screwless hole and the elastic member and bringing the elastic member into contact with the first end surface of the nut. Can be stopped. Thereby, it can prevent that the material for main-body part shaping | molding penetrate | invades in the screw hole of a nut in a formation process. As a result, it is not necessary to provide a process for removing the material adhering to the inner periphery of the screw hole after the molding process, and the number of manufacturing processes can be reduced, and the manufacturing labor can be significantly reduced.

Invention of Claim 4 is a metal mold | die for shape | molding the nut assembly of Claim 1 or 2, Comprising: The cavity for a main-body part shaping | molding, and the core pin which penetrates a cavity, A core pin is the following. A mold for molding a nut assembly including a shaft portion that fits into a screw hole of a nut and a screwless hole forming portion.
According to the present invention, by holding the nut on the core pin, the relative position between the screw hole and the screwless hole can be accurately positioned, and a nut embedded body with high dimensional accuracy can be formed.

Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 is a schematic partial cross-sectional side view of a nut assembly according to an embodiment of the present invention. 2 and 3 are partial cross-sectional side views each showing a state in which the fastening object is fastened using the nut assembly, and FIG. 2 shows a state in the middle of fastening the fastening object. 3 has shown the state which fastened the fastening object.

Referring to FIG. 1, a nut assembly 1 is for coupling with a screw or the like to fasten a fastening object such as a plate material, and includes a metal nut 2 as a nut and a first end face 3 of the metal nut 2. An annular elastic member 4 disposed adjacent to the main body 5 and a main body 5 for embedding and fixing a part of the metal nut 2 and the elastic member 4 are provided.
Referring to FIG. 2, the metal nut 2 is for screwing with the screw shaft 7 of the screw 6 and receiving an axial force, and is made of, for example, a square nut. The screw hole 8 of the metal nut 2 extends concentrically and parallel to the outer peripheral surface 9 of the metal nut 2 and penetrates the meat of the metal nut 2. The screw hole 8 is opened to the outside by openings 11 and 12 formed in the first end surface 3 and the second end surface 10 of the metal nut 2, respectively. The first and second end surfaces 3 and 10 are formed as flat surfaces and extend in parallel to each other.

The main body 5 is coupled to the screw shaft 7 to prevent the screw shaft 7 from loosening, protects the metal nut 2 from deterioration such as corrosion and electrolytic corrosion, and is in close contact with the fastening objects 70 and 71 made of a plate material or the like. Thus, foreign matter is prevented from entering the screw insertion holes 72 and 73 of the fastening objects 70 and 71.
The main body 5 is formed using a material containing a thermoplastic elastomer. Examples of the thermoplastic elastomer include styrene elastomers, olefin elastomers, vinyl chloride elastomers, polyamide elastomers, and polyurethane elastomers. Examples of polyurethane elastomers include polyether elastomers and polyester elastomers. Furthermore, it is preferable that the thermoplastic elastomer has a D hardness of 45 to 65 in terms of heat resistance and durability.

The main body portion 5 includes a cover portion 16 as a portion covering the first end surface 3 of the metal nut 2, and a peripheral side portion 17 connected to the lower end portion of the cover portion 16 and surrounding the metal nut 2 (outer peripheral surface 9). , And a seat portion 18 connected to the lower end portion of the peripheral side portion 17. The cover portion 16, the peripheral side portion 17, and the seat portion 18 are integrally formed of a single member.
The cover part 16 is formed in a truncated cone shape, for example, and is disposed above the metal nut 2. A screwless hole 20 is formed in the cover portion 16 concentrically with the screw hole 8 of the metal nut 2, and penetrates the cover portion 16.

  One end of the screwless hole 20 is open to the upper end surface of the cover portion 16, and the other end communicates with the screw hole 8 via the elastic member 4. The screwless hole 20 has a surface that does not include a screw hole, and the inner diameter A is set to a smaller diameter (A <B) than the valley diameter B (which may be an effective diameter) of the screw hole 8 of the metal nut 2. ing. Furthermore, the inner diameter A of the screwless hole 20 is preferably larger than the crest diameter of the screw hole 8 of the metal nut 2.

For example, the peripheral side portion 17 is formed in a truncated cone shape like the cover portion 16, and is disposed on the outer side in the radial direction of the metal nut 2 to cover the outer peripheral surface 9 of the metal nut 2. The outer peripheral surface 21 of the peripheral side portion 17 is smoothly connected to the outer peripheral surface 19 of the cover portion 16.
An annular receiving surface 22 is formed inside the peripheral side portion 17, and the first end surface 3 of the metal nut 2 is in contact with the receiving surface 22. As a result, the metal nut 2 is prevented from being detached (removed) upward from the main body 5. Further, the inner peripheral surface 23 of the peripheral side portion 17 is in contact with the outer peripheral surface 9 of the metal nut 2.

The seat 18 is for receiving the fastening object 70 and covers at least a part of the second end face 10 of the metal nut 2. The seat portion 18 is formed in a disk shape having a larger diameter than the lower end portion of the peripheral side portion 17 and has a predetermined thickness in the vertical direction.
A large-diameter hole 24 is formed in the seat portion 18 concentrically with the screw hole 8. The inner diameter E of the large diameter hole 24 is larger (E> C) than the outer diameter C (crest diameter) of the screw shaft 7, and the screw shaft 7 is introduced into the screw hole 8. The large-diameter hole 24 passes through the seat portion 18 in the axial direction, is continuous with the screw hole 8 of the metal nut 2, and opens to the seat surface 25. Of the second end face 10 of the metal nut 2, the peripheral edge of the opening 12 is exposed to the seating face 25 side. Further, a part of the radially outer portion of the large-diameter hole 24 in the seat portion 18 receives a part of the second end face 10 of the metal nut 2.

  A mortar-shaped recess 27 for increasing the frictional engagement force with the surface 74 of the fastening object 70 is formed on substantially the entire seat surface 25 (lower end surface) of the seat portion 18. The depth of the recess 27 (the distance from the surface 74 of the fastening object 70) increases as it goes from the outer periphery to the inner periphery of the seat surface 25. The recess 27 may be formed on the entire surface of the seating surface 25 or may be formed only on a part around the large diameter hole 24.

A knob portion 28 is extended on the outer peripheral surfaces 16 and 21 of the cover portion 16 and the peripheral side portion 17. A plurality (two in this embodiment) of knobs 28 are arranged at equal intervals along the circumferential direction of the nut assembly 1. Each knob | pick part 28 is formed in plate shape, and these nuts 28 can be picked by hand, for example, and the nut built-in body 1 can be rotated.
When the nut assembly 1 fastens the fastening objects 70 and 71, the metal nut 2 prevents the seat portion 18 from expanding and prevents the metal nut 2 from being detached from the main body portion 5. Referring to FIG. 2 and FIG. 4 which is a perspective view of the metal nut 2, specifically, the metal nut 2 has a protrusion 29 as a diameter expansion suppressing protrusion. For example, a plurality of protrusions 29 are provided on the outer peripheral edge of the second end surface 10 of the metal nut 2 by welding (four in the present embodiment) at equal intervals in the circumferential direction, and each of the second end surfaces 10. Projecting downward. Each protrusion 29 is disposed radially outward of the large-diameter hole 24 and embedded in the seat portion 18, and restricts relative rotation between the main body portion 5 and the metal nut 2.

  With reference to FIG. 1, the elastic member 4 is for preventing the material for molding the main body portion from entering the screw hole 8 of the metal nut 2 when the main body portion 5 is molded. The elastic member 4 is formed, for example, in an O-ring shape using a material having a melting point higher than that of the main body 5. Examples of the material used for the elastic member 4 include NBR (Nitrile Butadiene Rubber) and urethane. The elastic member 4 may be formed of the same material as that of the main body 5. Furthermore, it is preferable that the D material has a D hardness of 40 to 45 as the material described above in terms of sufficiently securing the elasticity of the elastic member 4 and obtaining a good sealing effect.

  The elastic member 4 has an annular embedded portion 30 embedded in the main body portion 5 along the inner periphery of the screwless hole 20 and an exposure that protrudes from the inner periphery of the screwless hole 20 and forms a substantially concentric ring with the metal nut 2. An annular contact that surrounds the periphery of the opening 11 (screw hole 8) of the first end surface 3 of the metal nut 2 from the outside in the radial direction in a state of elastically contacting the portion 31 and the first end surface 3 of the metal nut 2. Part 32.

In the initial state (the state where the screw shaft 7 has not been inserted), the inner diameter D of the exposed portion 31 is smaller than the inner diameter A of the screwless hole 20 (D <A).
The above is the schematic configuration of the nut assembly 1. Next, the case where the fastening object is fastened using the nut assembly 1 will be described.
Referring to FIG. 2, when the screw 6 and the nut assembly 1 are coupled to fasten the fastening objects 70 and 71, first, the screw shaft 7 of the screw 6 is inserted into the screw insertion hole of the fastening objects 70 and 71. 72 and 73 and the large-diameter hole 24 of the nut assembly 1 are inserted. Next, the knob portion 28 of the nut assembly 1 is picked by hand, for example, and the nut assembly 1 is rotated with respect to the screw shaft 7.

As a result, the screw shaft 7 is screwed into the metal nut 2 and engaged with the unthreaded hole 20 of the main body 5, and the inner peripheral surface of the unthreaded hole 20 is elastically deformed to be screwed onto the thread of the screw shaft 7. A mating screw hole 33 is formed. As a result, the screw shaft 7 is coupled to the nut assembly 1 and the space between the screwless hole 20 and the screw shaft 7 is sealed.
Further, as the nut assembly 1 is rotated with respect to the screw shaft 7, the metal nut 2 is moved to the fastening member 70 side (downward) by screwing with the screw shaft 7, as shown in FIG. The meat of the seat 18 is pressed downward. Accordingly, the seat portion 18 is pressed between the metal nut 2 and the fastening member 70, and the seat surface 25 is pressed against the peripheral edge (surface 74) of the screw insertion hole 72 of the fastening member 70. As a result, the recess 27 of the seating surface 25 is deformed flat and comes into close contact with the surface 74.

  When the metal nut 2 moves toward the fastening object 70 and the tips of the protrusions 29 are received by the surface 74 of the fastening member 70, the downward movement of the metal nut 2 is restricted. As a result, the second end face 10 of the metal nut 2 is prevented from reaching the seat surface 25, and the diameter of the seat portion 18 is prevented from being increased by the protrusions 29. As a result, the metal nut 2 Is prevented from detaching from the main body 5.

FIG. 5 is a schematic partial cross-sectional side view of a mold 40 for molding the nut assembly 1. Referring to FIGS. 1 and 5, the mold 40 includes a cavity 41 for forming a main body part and a core pin 42 through which the cavity 41 is inserted.
The cavity 41 is partitioned by a cavity portion 43. The cavity portion 43 includes a first portion 44 for forming outer surface shapes such as the cover portion 16, the peripheral side portion 17, and the knob portion 28, and a first portion 44 for forming the outer surface shapes such as the seat portion 18. 2 portion 45.

The first and second portions 44 and 45 are in contact with each other at their respective parting surfaces 46 and 47, and the cavity 43 can be divided by these parting surfaces 46 and 47. The bottom surface of the second portion 45 is formed in a shape corresponding to the shape of the seat surface 25 of the seat portion 18, and the core pin 42 is erected at the center portion of the bottom surface.
The core pin 42 is formed integrally with the second portion 45 of the cavity portion 43 by a single member, and has a large diameter portion 48 for forming the large diameter hole 24 of the seat portion 18, and the large diameter portion 48. A shaft portion 58 that is disposed above and is fitted into the screw hole 8 of the metal nut 2 and a screwless hole forming portion 49 disposed above the shaft portion 58 are provided. The upper end of the large diameter portion 48 is an annular step portion 50. The annular step portion 50 extends in the horizontal direction (the left-right direction in FIG. 5) and can receive the second end surface 10 of the metal nut 2.

  The unthreaded hole forming portion 49 is for forming the unthreaded hole 20 and is formed in a cylindrical shape having an outer diameter equal to the inner diameter of the unthreaded hole 20. The screwless hole forming portion 49 and the shaft portion 58 are formed in the same shape and are smoothly connected. In a state where the metal nut 2 is inserted through the shaft portion 58, the screwless hole forming portion 49 protrudes from the first end surface 3 of the metal nut 2.

An engagement convex portion 51 is formed at the upper end of the screwless hole forming portion 49 and is fitted to the engagement concave portion 52 formed in the first portion 44. Thereby, the core pin 42 can be accurately positioned with respect to the first portion 44.
The above is the schematic configuration of the mold 40. Next, a method for manufacturing the nut assembly 1 will be described. The method for manufacturing the nut assembly 1 includes a preparation process for setting the metal nut 2 and the elastic member 4 in the cavity 41 of the mold 40, and a molding process for molding the main body 5 in the cavity 41.

  Specifically, first, in the preparation step, the first and second portions 44 and 45 of the cavity portion 43 are separated from each other (see FIG. 6), and in this state, the screw hole of the metal nut 2 is formed in the core pin 42. 8 and the exposed portion 31 of the elastic member 4 are inserted (fitted). At this time, the second end face 10 of the metal nut 2 is brought into contact with the annular step 50 of the core pin 42, and the opening 12 of the second end face 10 is sealed with the annular step 50. Further, the inner periphery of the exposed portion 31 of the elastic member 4 and the outer periphery of the screwless hole forming portion 49 are brought into close contact with each other, and the contact portion 32 of the elastic member 4 and the first end surface 3 of the metal nut 2 are brought into contact with each other. The opening 11 is sealed. Next, as shown in FIG. 7, the cavity 41 is defined by aligning the parting surfaces 46 and 47 of the first and second portions 44 and 45 of the cavity portion 43 with each other.

Then, as shown in FIG. 8, in the molding process, a main body forming material is injected into the cavity 41 from a gate (not shown) to mold the main body 5.
As described above, according to the present embodiment, the core pin 42 of the mold 40 is inserted into the exposed portion 31 of the elastic member 4 so that the outer periphery of the core pin 42 and the inner periphery of the exposed portion 31 are in close contact with each other. The opening 11 of the first end surface 3 of the metal nut 2 can be sealed by the cooperation of the elastic member 4 and the core pin 42. Moreover, the opening 12 of the second end surface 10 of the metal nut 2 can be sealed by bringing the annular step portion 50 of the core pin 42 into contact with the second end surface 10 of the metal nut 2.

This prevents the material injected into the cavity 41 of the mold 40 from entering the screw hole 8 of the metal nut 2 when the metal nut 2 is inserted to form the main body 5 (unthreaded hole 20). it can.
As a result, it is possible to prevent the material for molding the main body from adhering to the inner peripheral surface of the screw hole 8, so that the work of removing the material adhering to the inner peripheral surface of the screw hole 8 becomes unnecessary, and labor for manufacturing is eliminated. It can be remarkably reduced.

  When the screw 6 and the nut assembly 1 are coupled and the fastening objects 70 and 71 are fastened, the metal nut 2 is moved to the fastening object 70 side by screwing with the screw shaft 7 of the screw 6 and is seated. By compressing the portion 18 and increasing the diameter of the seat portion 18 (large diameter hole 24), it becomes easy to detach from the main body portion 5. However, since the protrusion 29 can suppress the diameter of the seat portion 18 from being increased, The nut 2 can be reliably prevented from being detached from the main body 5.

  Further, when the nut assembly 1 is molded, the unthreaded hole forming portion 49 of the core pin 42 and the exposed portion 31 of the elastic member 4 are fitted together, and the contact portion 32 of the elastic member 4 is connected to the first nut of the metal nut 2. The opening 11 of the first and second end surfaces 3, 10 of the metal nut 2 is a simple preparatory work for contacting the end surface 3 and bringing the second end surface 10 into contact with the annular step portion 50 of the core pin 42. , 12 can be sealed.

Thereby, as above-mentioned, it can prevent that the material for main-body part shaping | molding penetrate | invades into the screw hole 8 of the metal nut 2 in a shaping | molding process. As a result, there is no need to provide a process for removing the material for molding the main body adhering to the inner periphery of the screw hole 8 after the molding process, and the number of manufacturing processes can be reduced to significantly reduce the manufacturing effort. can do.
In addition, by holding the metal nut 2 on the core pin 42, the relative position between the screw hole 8 and the screwless hole 20 can be accurately determined, and the nut assembly 1 with high dimensional accuracy is formed. Can do.

FIG. 9 is a partial cross-sectional side view of a mold 40A according to another embodiment of the present invention. In the following, differences from the embodiment shown in FIG. 5 will be mainly described, and the same components are denoted by the same reference numerals and description thereof will be omitted.
In the present embodiment, a core pin 42A is used instead of the core pin 42 as shown in FIG. The core pin 42A is formed separately from the first and second portions 44A and 45A of the cavity portion 43A, and is a shaft for screwing (fitting) into the screw hole 8 (see FIG. 1) of the metal nut 2. A screw portion 53 as a portion, a screwless hole forming portion 49 disposed above the screw portion 53, and a screwless hole forming portion 49 disposed above the screwless hole forming portion 49 and fitted in the fitting hole 54 of the first portion 44A. The fitting part 55 to be provided is provided.

  The screw portion 53 is opposed to the large diameter portion 48A provided on the bottom surface of the second portion 45A in the vertical direction. The fitting portion 55 is formed in a shape (for example, a columnar shape) corresponding to the shape of the fitting hole 54 of the first portion 44 </ b> A and is fitted in the fitting hole 54. Thereby, the core pin 42A is positioned while being held by the first portion 44A. An annular flange 56 is provided at the lower end of the fitting portion 55 to prevent the material for molding the main body injected into the cavity 41 from entering the fitting hole 54.

As shown in FIG. 10, when the metal nut 2 and the elastic member 4 are set on the core pin 42A and the core pin 42A is inserted into the cavity 41 (preparation step), the upper end surface 57 of the large diameter portion 48A and the metal nut 2 The opening 12 of the second end surface 10 is sealed by the contact with the second end surface 10.
According to the present embodiment, by holding the metal nut 2 on the core pin 42A, the relative position between the screw hole 8 and the screwless hole 20 can be accurately determined, and a nut incorporated with high dimensional accuracy. The body 1 can be molded. Further, since the core pin 42A is formed separately from the cavity portion 43A, the core pin 42A can be attached to another cavity portion, and the core pin 42A can have versatility.

  The present invention is not limited to the above embodiments. For example, in the embodiment shown in FIG. 5, the core pin 42 may be formed separately from the second portion 45 of the cavity portion 43, or the screw portion 53 may be provided on the core pin 42. In the embodiment shown in FIG. 9, the core pin 42A may be formed integrally with the first portion 44A of the cavity portion 43A by a single member, or the shaft portion 58 may be provided on the core pin 42A. .

Further, in each of the above embodiments, an elastic member adjacent to the second end surface 10 of the metal nut 2 is further provided, and this elastic member is brought into contact with the second end surface 10 in the same manner as the elastic member 4. May be. In this case, the opening 12 of the second end face 10 can be sealed, and unthreaded holes can be provided both above and below the metal nut 2.
The metal nut 2 may be a triangular nut or a polygonal nut having five or more corners. Further, a resin nut may be used instead of the metal nut 2. Examples of the material used for the resin nut include materials having a melting point higher than that of the main body 5 such as PA (PolyAmide, nylon), PC (PolyCarbonate), and POM (PolyOxyMethylene, Duracon).

  Further, the number of the protrusions 29 may be any one of 1 to 3, and may be 5 or more. Further, the protrusion 29 may be eliminated. Moreover, you may shape | mold the elastic member 4 and the main-body part 5 by 2 color molding. Furthermore, when using a resin nut, in addition to the elastic member 4 and the main body portion 5, the resin nut may be formed by two-color molding (multicolor molding).

It is a typical partial cross section side view of the nut assembly concerning one embodiment of the present invention. It is a partial cross section side view which shows a mode that the fastening object is fastened using a nut assembly, and has shown the state in the middle of fastening the fastening object. It is a partial cross section side view which shows a mode that the fastening object is fastened using a nut assembly, and has shown the state which fastened the fastening object. It is a perspective view of a metal nut. It is a typical partial cross section side view of the metal mold | die for shape | molding a nut embedding body. It is a figure for demonstrating a preparatory process, and has shown the state from which the 1st and 2nd part of the cavity part was mutually isolate | separated. It is a figure for demonstrating a preparatory process, and has shown the state by which the 1st and 2nd part of the cavity part was mutually engaged. It is a figure for demonstrating a formation process. It is a partial cross section side view of the metal mold | die concerning other embodiment of this invention. It is a figure for demonstrating a preparatory process.

Explanation of symbols

1 Nut assembly 2 Metal nut (nut)
DESCRIPTION OF SYMBOLS 3 1st end surface 4 Elastic member 5 Main-body part 7 Screw shaft 8 Screw hole 10 2nd end surface 16 Covering part (part which covers 1st end surface)
17 Peripheral side portion 18 Seat portion 20 Screwless hole 24 Large diameter hole 29 Protrusion (expansion suppression protrusion)
30 Buried part 31 Exposed part 32 Contact part 40, 40A Mold 41 Cavity 42, 42A Core pin 49 Unthreaded hole forming part 53 Screw part (shaft part)
58 Shaft 70, 71 Fastening object A (Inner diameter of screwless hole) B (Threaded hole) Valley diameter C (Screw shaft) Outer diameter E (Large diameter hole) Inner diameter

Claims (4)

A screw hole for screwing onto the screw shaft, and a nut having first and second end faces in which the screw hole opens;
An annular elastic member disposed adjacent to the first end face of the nut;
Formed using a material containing a thermoplastic elastomer, comprising a nut and a body portion for embedding and fixing a part of the elastic member,
The main body includes a peripheral side portion surrounding the periphery of the nut, a portion covering the first end surface of the nut, and a screwless hole formed in a portion covering the first end surface of the nut and continuing to the screw hole of the nut. Including, the inner diameter of the screwless hole is smaller than the valley diameter of the screw hole of the nut,
The elastic member includes an annular embedded portion embedded in the main body along the inner periphery of the screwless hole, an exposed portion that protrudes from the inner periphery of the screwless hole and forms a concentric ring with the nut, and a first nut And an annular contact portion surrounding the periphery of the screw hole of the nut in a state of elastically contacting the end face of the nut assembly. The main body according to claim 1, further comprising a seat for covering at least a part of the second end surface of the nut and receiving an object to be fastened, and a large-diameter hole formed in the seat and connected to the screw hole of the nut. Including
The inner diameter of the large hole is larger than the outer diameter of the screw shaft,
The nut assembly further includes a diameter expansion suppression protrusion embedded in the seat portion of the main body portion and suppressing the diameter expansion of the seat portion. A method of manufacturing a nut assembly according to claim 1 or 2,
A preparation step of setting a nut and an elastic member in a cavity for molding a main body of a mold;
A molding step of molding the main body in the cavity,
In the preparation step, the nut assembly is characterized in that the elastic member is in contact with the first end surface of the nut in a state where the elastic member is fitted to a part of the core pin for forming the screwless hole. A method of manufacturing a solid. A mold for molding the nut assembly according to claim 1 or 2,
A cavity for molding the main body,
A core pin inserted through the cavity,
The core pin includes a shaft portion that fits into a screw hole of the nut, and a screwless hole forming portion, and is a mold for forming a nut assembly.

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