JPH0558267U - Insert metal fittings - Google Patents

Abstract

(57) [Summary] [Purpose] Provision of insert fittings. A cylindrical insert metal fitting 1 is embedded in a mounting member such as a synthetic resin or putty, and is screwed with a bolt member 10 to connect another member 14.
A female screw portion 2 for screwing in is formed, and the bolt member 1
At least the tip portion in the screwing direction of 0 is divided into a plurality of divided pieces 5, and the inner surface of the portion where the divided pieces 5 are formed forms a tapered surface 6 whose diameter gradually decreases toward the end portion. [Effect] Since each divided piece of the insert fitting bites into the local portion of the mounting member and is firmly fixed, the bolt member can be tightened with a required torque without cracking the mounting member.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to an insert fitting used for synthetic resin (FRP), putty and the like.

[0002]

[Prior Art]

 As a conventional insert metal fitting of this type, one shown in FIG. 5 is known. That is, it has a cylindrical shape with a bottom, an internal thread portion 101 for screwing a bolt member (not shown) is formed on the inner surface, an annular groove 102 is formed on the outer surface, and a knurl 103 is cut on the entire surface except the annular groove 102. is there. In such an insert fitting 100, a synthetic resin is applied to the outer surface including the annular groove 102, and is press-fitted and fixed in a hole 104a of a mounting member 104 made of synthetic resin (for example, FRP) or putty. Then, a bolt member is fastened to the female screw portion 101 to join another member.

[0003]

[Problems to be solved by the device]

 However, in such a conventional insert fitting 100, since the connection with the attachment member 104 is ensured by the adhesive force of the synthetic resin and the frictional force of the knurl 103, the bolt member is screwed in. At this time, if it is strongly tightened, the insert fitting 100 and the bolt member will rotate together, and thereafter, there is a technical problem that the connecting force with the mounting member 104 cannot be obtained at all. From the viewpoint of preventing this co-rotation, if the hole 104a of the mounting member 104 is formed to be small and the insert metal fitting 100 is pushed in strongly, a crack is generated at the peripheral edge of the hole 104a, and the mounting is similarly performed. It is not possible to secure the required bonding force with the member 104. For this reason, in the conventional insert fitting 100, it is often impossible to apply the torque necessary for firmly fixing the other member to the bolt member.

[0004]

Means for Solving the Problems The present invention has been made in view of the above-mentioned conventional technical problems, and the structure thereof is embedded in a mounting member such as a synthetic resin or putty and screwed with a bolt member. A cylindrical insert fitting for connecting other members by forming an internal thread portion for screwing the bolt member on the inner surface, and at least the tip end portion of the bolt member in the screwing direction extends in the center axis direction. The insert fitting is characterized in that it is divided into a plurality of divided pieces by a portion, and the inner surface of the place where the divided pieces are formed forms a tapered surface whose diameter gradually decreases toward the end. Then, an annular recess can be formed on the outer surface of the base of each divided piece.

[0005]

[Action]

 Insert fittings coated with synthetic resin into the holes of the mounting member made of synthetic resin (FRP), putty, etc. so that at least a part of each divided piece is located inside the mounting member. Since the outer surface of the insert fitting has the same outer shape when the bolt member is not screwed, it is relatively easily press-fitted into the mounting member.

Next, the bolt member is tightened into the female screw portion of the press-fitted insert fitting to join the other member. When the bolt member is screwed, the tip of the bolt member enters the taper surface of which the diameter is gradually reduced, and the plurality of divided pieces divided by the cutout portion are pushed outward in the radial direction. Each of the divided spread pieces bites into the mounting member locally, and the insert fitting of the insert metal fitting to the mounting member becomes stronger. By forming an annular recess on the outer surface of the base of each divided piece, each divided piece can be easily spread. Therefore, it is possible to connect the other member to the mounting member by applying a required torque to the bolt member.

At the base end of the bolt member of the insert fitting in the screwing direction, a split piece divided into a plurality of pieces by a cutout extending in the central axis direction and a tapered surface gradually decreasing in diameter toward the end are provided. If formed, the divided pieces that have been pushed and spread at both ends in the screwing direction of the bolt member locally bite into the mounting member, so that the insert fitting is more firmly press-fitted and fixed to the mounting member. However, in that case, it is preferable to thread a female screw also on the tapered surface of the base end portion so that a bolt member having a slightly reduced diameter at the tip can be easily screwed into the insert fitting.

[0008]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 3 show an insert fitting according to an embodiment of the present invention. In the figure, reference numeral 1 indicates an insert metal fitting, which has a cylindrical shape as a whole. An inner surface of the insert fitting 1 on the base end side forms a cylindrical surface having the same diameter, and an internal thread portion 2 into which the bolt member 10 is screwed is formed on the cylindrical surface. Further, a plurality of slit-shaped incisions 4 extending in the central axis direction (eight in this embodiment) are formed at the tip of the bolt member 10 in the screwing direction, and the same number of divided pieces are formed. In addition to being divided into five, the outer surface of the end portion where the divided piece 5 is formed has the same outer shape as the outer surface of the base end side in the non-threaded state of the bolt member 10.

On the other hand, the inner surface of the portion where the divided piece 5 is formed forms a tapered surface 6 whose diameter gradually decreases toward the end. Further, an annular recess 8 is formed on the outer surface of the divided piece 5 at the base end portion thereof. Such insert metal fitting 1 is embedded in the hole 12a of the mounting member 12 made of synthetic resin, putty or the like, and is used for screwing the bolt member 10 to join the other member 14.

Next, the operation of the above embodiment will be described. The mounting member 12 is made of FRP, for example, and has a through hole 12a which is smaller than the outer shape of the insert fitting 1 and is formed in advance. The insert metal fitting 1 whose outer surface including the annular recess 8 is coated with synthetic resin is press-fitted into the hole 12a, and the tip end of each divided piece 5 is projected to the back surface side of the mounting member 12. The outer surface of the insert fitting 1 excluding the annular recess 8 has substantially the same outer shape when the bolt member 10 is in a non-threaded state, so that it can be relatively easily press-fitted into the mounting member 12.

Next, the bolt member 10 is tightened into the press-fitted insert fitting 1 to join the other member 14. That is, the bolt member 10 passed through the through hole 14a of the other member 14 is inserted into the insert fitting 1 and screwed into the female screw portion 2. When the bolt member 10 is screwed, the tip of the bolt member 10 enters the tapered surface 6 whose diameter is gradually reduced. Since a plurality of incisions 4 extending in the central axis direction are formed in the circumferential direction at the location where the taper surface 6 is formed, that is, at the tip end, each divided piece 5 is attached as the bolt member 10 is screwed. It can be pushed outward in the radial direction.

Since the annular recess 8 is formed on the outer surface of the base of each of the divided pieces 5 to form a thin wall, the divided pieces 5 are easily pushed apart and bite into the vicinity of the back surface of the mounting member 12 to insert the insert. The metal fitting 1 is more firmly press-fitted and fixed to the mounting member 12. Since each of the divided pieces 5 is pushed and spread with the tip end thereof slightly protruding from the mounting member 12 and is locked to the back surface of the mounting member 12, the insert fitting 1 is removed by screwing the bolt member 10 or the like. Removal is also prevented satisfactorily.

Therefore, the insert fitting 1 is fixed by the frictional force by press fitting into the hole 12a of the mounting member 12, the adhesive force by the synthetic resin applied to the outer surface, and the biting of each divided piece 5. .. Therefore, the other member 14 can be coupled to the mounting member 12 by applying a required torque to the bolt member 10 without causing the bolt member 10 and the insert fitting 1 to rotate together. The FRP mounting member 12 is a member that easily cracks, but compared to the conventional structure in which the insert metal fitting 1 is press-fitted and bonded to the mounting member 12, the press-fitted state is relaxed to prevent cracking and is firm. You can get a fixed state.

FIG. 4 shows another mounting example of the insert fitting 1, in which the mounting member 12 has the honeycomb structure 22 as a main constituent element. That is, the attachment member 12 has a through hole 22a formed in a part of a honeycomb structure 22 made of aluminum or the like filled with a filling material 22b made of synthetic resin, putty, or the like, and both sides of the skin 2 made of an aluminum plate or the like. 2c respectively.

Then, one skin 22c and a part of the filler 22b are perforated to form a bottomed hole 22d, and the insert fitting 1 is press-fitted into this hole 22d. According to this structural example, when the bolt member 10 is screwed into the female screw portion 2 of the insert fitting 1 and the tip of the bolt member 10 is pushed into the tapered surface 6, each divided piece 5 is expanded and the mounting member 12 is attached. It cuts into the middle portion of the filler 22b. As a result, the insert fitting 1 is firmly press-fitted and fixed to the mounting member 12. Since the filling material 22b of the mounting member 12 is made of synthetic resin, a material such as putty that is unlikely to cause cracks, the tip of each divided piece 5 is largely digged into the middle portion of the filling material 22b to fix the insert fitting 1 by press fitting. It can be obtained more strongly.

[0016]

[Effect of the device]

 As can be understood from the above description, according to the present invention, the fixing state of the insert metal fitting to the mounting member can be firmly obtained by each divided piece biting into the local portion of the mounting member. It is possible to firmly fix other members by tightening the bolt member with the required torque without causing damage such as cracks on the bolt.

[Brief description of drawings]

FIG. 1 is a front view showing an insert fitting according to an embodiment of the present invention.

FIG. 2 is a front view showing the insert fitting by partially cutting it.

FIG. 3 is a bottom view of the insert fitting.

FIG. 4 is a front view showing another mounting example of the insert fitting.

FIG. 5 is a front view showing a conventional example with a partial incision.

[Explanation of symbols]

1: Insert metal fitting, 2: Female thread part, 4: Incision part, 5:
Divided pieces, 6: tapered surface, 8: annular recess, 10: bolt member, 12: mounting member, 12a: hole, 14: other member,
22: Honeycomb structure, 22a: through hole, 22b: filler, 22c: skin, 22d: hole.

Claims (2)

[Scope of utility model registration request] 1. A cylindrical insert fitting embedded in a mounting member such as a synthetic resin or putty and screwing a bolt member to join other members, wherein an internal thread portion for screwing the bolt member into an inner surface is provided. At least the tip of the bolt member in the screwing direction is divided into a plurality of divided pieces by a cutout extending in the central axis direction, and the inner surface of the portion where the divided piece is formed faces the end. Insert metal fittings characterized by forming a tapered surface that gradually decreases in diameter. 2. The insert fitting according to claim 1, wherein an annular recess is formed on the outer surface of the base of each divided piece.