JPH07208423A - Plastic made blind rivet - Google Patents

Abstract

PURPOSE:To offer a blind rivet capable of removing itself simply and reusing itself after removal as maintaining the strong connecting force of the conventional blind rivet. CONSTITUTION:A blind rivet 15 has its pipe member 18 and a mandrel 19 formed of plastic and a cylindrical part 16 of the pipe member 18 is divided by a slit and its end part can be bent so as to enlarge the diameter. The mandrel 19, which incorporates a large diameter head part 21 enlarging the end of the cylindric part of the pipe member 18 and a shaft extending from the head part 21, is inserted into the pipe member 18 and the head part 21 enlarges the diameter of the end of the pipe member 18 by drawing out the mandrel shaft from the pipe member, while a shaft part 30 protruding from the flange 17 is formed so as to be reptured by drawing out the shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blind rivet suitable for connecting a decorative member or the like to an automobile body panel or the like, and more particularly to a hollow plastic tubular member consisting of a tubular portion and a flange at one end, A plastic blind rivet comprising a plastic mandrel which is inserted into the tubular member to expand the tubular member by pulling.

[0002]

2. Description of the Related Art Blind rivets used to attach one mounting member such as a body panel of an automobile to another mounting member such as a decorative member are well known. FIG. 1 shows how a well-known blind rivet 1 connects another mounting member 3 such as a decorative member to a mounting member 2 such as an automobile body panel. The blind rivet 1 includes a hollow tubular member 6 including a tubular portion 4 and a flange 5, and a mandrel 7 that is inserted into the tubular member 6 and expands the tubular member 6 by pulling it out. The mandrel 7 has a large diameter head 8.
And a shaft portion 9, and a small-diameter portion 10 for breaking is formed on the shaft portion 9. The blind rivet 1 is inserted into the mounting holes of the mounting members 2 and 3 as shown in FIG.
Is inserted and the shaft portion 9 of the mandrel 7 is gripped by the jaw 12 of the fastening tool 11. Next, as shown in FIG. 1 (B), the jaw 12 is pulled up to attach the mandrel 7 to the tubular member 6
The pulling operation is continued until the shaft portion 9 breaks at the small diameter portion 10. By this pulling out, the mandrel head portion 8 buckles so as to expand the tubular portion 4 of the tubular member, and the tubular member portion 13 and the flange 5 having the enlarged diameter connect the attachment members 2 and 3 to each other.

[0003]

The above-mentioned blind rivet is widely used because it has a strong force for connecting two or more mounting members to each other. However, in such a known blind rivet, when the mounting member is removed for repair or the like, the tubular member of the blind rivet must be broken. Therefore, the removal work is troublesome,
Moreover, since the tubular member is destroyed, the blind rivet cannot be reused after the removal.

Therefore, it is an object of the present invention to provide a plastic blind rivet which can be easily removed and can be reused after being removed while maintaining a strong connection force of the blind rivet.

[0005]

In order to achieve the above object, in the blind rivet of the present invention, the tubular member and the mandrel are made of plastic, and the tubular portion of the tubular member is divided by an axial slit. The end portion can be bent so as to expand its diameter, and the mandrel has a large-diameter head portion that expands the end portion of the tubular member tubular portion, and a shaft portion that extends from this head portion. , With its head adjacent to the end of the tubular member and with the shank extending through the flange of the tubular member, inserted into the tubular member and pulling the mandrel shank from the tubular member. It is characterized in that the portion is formed such that the diameter of the end portion of the tubular member is expanded and the shaft portion is pulled out so that the shaft portion portion protruding from the flange is broken.

[0006]

With the above features, the jaw of the fastening tool can pull the mandrel out of the tubular member with such a strong force that it breaks in the small diameter portion, and this strong force causes the end of the tubular portion of the tubular member to expand with the mandrel head. The diameter can be made larger, and thus a strong connecting force can be obtained. Further, in disconnecting the connection, the mandrel head portion and the tubular portion end portion of the tubular member can be disengaged by strongly pushing the broken end portion of the mandrel into the mandrel. Also,
In the reuse, the broken mandrel is once pulled out from the tubular member and separated, the tubular member is inserted into the mounting hole of the mounting member, the mandrel is strongly pushed from the flange side of the tubular member, and the mandrel head and the tubular portion of the tubular member are inserted. The end may be engaged.

According to the present invention, the end portion of the tubular portion of the tubular member is projected inward in the radial direction, and the small diameter portion for receiving the inwardly projecting portion of the end portion of the tubular portion between the head and the shaft portion of the mandrel. By forming the mandrel so that the small diameter portion does not expand the end portion of the tubular portion when the mandrel is inserted into the tubular member, the mandrel and the tubular member can be handled in an assembled state. Further, the mandrel shaft portion is formed by a large-diameter shaft portion portion that is received in the tubular portion of the tubular member and a small-diameter shaft portion portion that extends from the flange of the tubular member and is gripped by the fastening tool. It is possible to form a small-diameter fracture portion that is fractured by the pulling-out operation of the shaft portion between the portion portion and the small-diameter shaft portion portion to facilitate the fracture.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 2, the plastic blind rivet 15 according to the present invention includes a hollow plastic tubular member 18 composed of a tubular portion 16 and a flange 17, and a tubular member 18 inserted into the tubular member 18 and pulled out. It consists of a mandrel 19 made of plastic that expands the diameter of the end of the portion 16, and is assembled and handled in the inserted state as shown in the figure. The details of the mandrel 19 are shown in FIG.
And details of tubular member 18 are shown in FIG. 5 to 7 show a procedure for fastening the blind rivet 15, and FIGS. 8 and 9 show cancellation of the fastening of the blind rivet.

The mandrel 19 has a large-diameter head portion 21 for enlarging the end portion of the tubular member tubular portion 16 and a shaft portion 22 extending from the head portion 21. The head portion 21 forms a tapered distal end portion 23 for easy insertion into the tubular member 18 and a groove 24 for receiving and holding the end portion of the tubular portion 16 in an engaged state and expanding the end portion of the tubular portion 16. The central portion formed to have a large diameter and the tubular portion 16 in the pulling operation of the mandrel 19
The taper portion 25 is provided to facilitate the expansion of the end portion of the. A small diameter portion 27 is formed between the taper portion 25 and the shaft portion 22 of the head portion 21 to receive the inward protruding portion formed at the end portion of the tubular portion, and the mandrel 19 is inserted into the tubular member 18. In the state, the small diameter portion 27 receives the end portion of the tubular portion 16 so as not to expand the diameter. As a result, as shown in FIGS. 2 and 5, the blind rivet 15 is assembled with the mandrel 19 and the tubular member 18 in an assembled state in which the tubular member tubular portion is not expanded in diameter.
It is convenient for delivery, parts management and use.

The shaft 22 of the mandrel 19 has a small diameter portion 27.
Adjacent to the first tubular member having a diameter of 1
The shaft portion 28 and the shaft portion 28 are formed to have a diameter larger than that of the first shaft portion 28, so that the shaft portion 28 can be assembled and removed (see FIG. 8).
2) in which the mandrel 19 is prevented from falling off the tubular member 18 by pushing.
And a small-diameter third shaft portion 30 that comes out of the flange 17 of the tubular member 18 and is gripped by the fastening tool. Between the large-diameter second shaft portion 29 and the small-diameter third shaft portion 30, there is formed a small-diameter fracture portion 31 which is fractured by the mandrel drawing operation. Therefore, the mandrel shaft portion 22
By the pulling-out operation, the head portion 21 moves so as to expand the end portion of the tubular member 18, and the pulling-out operation of this shaft portion causes the third shaft portion 30 protruding from the flange to break the broken portion 31.
Torn from. The diameter of the broken portion 31 is smaller than that of the small diameter portion 2.
The breaking force of the mandrel can be adjusted by changing it within the range of less than 7.

Next, the details of the tubular member 18 will be described with reference to FIG.
Will be described with reference to. The tubular member 18 is composed of a tubular portion 16 and a flange 17, and is hollow so that the mandrel 19 can be inserted therein. The tubular portion 16 is divided by a slit 33 extending axially from a position close to the flange 17 toward the end portion, and is formed so that the tubular portion end portion can be bent so as to expand its diameter. It is preferable that a plurality of the slits 33 are formed so that the diameter of the slits 33 is uniform around the slits. A projecting portion 35 that projects inward in the radial direction is formed at the end portion 34 of the tubular portion. As a result, the diameter of the end 34 can be increased, and the projection 35 is received in the groove 24 of the mandrel head 21, so that the engagement between the end 34 and the head 21 can be reliably maintained. The inner diameter of the projecting portion 35 is set to a size that can be received by the small diameter portion 27 of the mandrel 19 in a state where the diameter of the end portion 34 is not expanded. The inner diameter of the cylindrical portion 16 is formed to have a size to receive the first shaft portion 28 of the mandrel shaft portion 22 from the middle to the tip thereof, and from the middle to the flange 17
Up to the second shank portion 2 of the mandrel shank 22
9 is formed to be large, and a step portion 36 is formed at an intermediate position thereof. This step portion 36 is a tubular member 1.
When the mandrel 19 and the mandrel 19 are assembled and removed, the mandrel 19 is prevented from falling off the tubular member 18 by being pushed, and abuts the second shaft portion 29 of the mandrel 19.

As shown in FIGS. 2 and 5, the tubular member 18 and the mandrel 19 having the above-described structure are used in the mandrel 1.
9 is inserted into the tubular member 18 and used as a blind rivet 15 assembled. In this assembled state, the projecting portion 35 at the end of the tubular portion 16 of the tubular member 18 is received by the small diameter portion 27 of the mandrel 19, and the mandrel head 21 projects out from the end of the tubular portion. Further, the cylindrical portion 16 receives the first shaft portion 28 and the second shaft portion 29 of the mandrel, and the third shaft portion 30 receives the tubular member flange 17.
Protruding from. Further, the second shaft portion 29 of the mandrel 19 abuts on the stepped portion 36 of the tubular member 18 to prevent the mandrel 19 from falling off the tubular member 18 due to pushing.

6 and 7 show a procedure for attaching another mounting member 39 such as a decorative member to one mounting member 38 such as a body panel using the plastic blind rivet 15.
Will be described with reference to. The plastic blind rivet 15 has a mandrel 19 inserted into a tubular member 18 as shown in FIGS. 2 and 5. With this blind rivet 15, the tubular portion 16 of the tubular member 18 is inserted into the attachment holes of one attachment member 38 and another attachment member 39, and the flange 1
7 is brought into contact with the mounting member 38. The third shaft portion 30 of the mandrel 19 extending upward from the flange 17 is held by the jaw 12 of the blind rivet fastening tool 11. When the blind rivet fastening tool is operated, the jaw 12 is pulled up, the third shaft portion 30 of the mandrel 19 is pulled up, and the mandrel 19 is pulled out. By this pulling-out operation, as shown in FIG. 7, the head portion 21 of the mandrel 19 enters the end portion of the tubular portion 16 of the tubular member 18, and the tubular portion 16 is expanded by the slit 33 (see FIG. 4), and the head portion is expanded. A projection 35 is received in the groove 24 of 21.
Further, if the pulling operation of the mandrel 19 is continued, the second
The shaft portion 29 is prevented from being further pulled out by the tip portion of the blind rivet fastening tool.
Only the third shaft portion 30 is pulled up by 2 and the mandrel 19 is broken at the breaking portion 31. This allows
The blind rivet 15 is in the state shown in FIG. 7, and connects the attachment members 38 and 39 to each other.

An operation for removing the blind rivet 15 will be described with reference to FIGS. 8 and 9. At the time of removal, the second shaft portion 29 of the mandrel 19 is moved to the arrow 40
The head portion 21 of the mandrel 19 causes the protruding portion 3 of the tubular portion 16 of the tubular member 18 to be pushed strongly in this direction.
When pushed down from 5, the tubular portion 16 returns from the expanded diameter state to the original state. This indentation is stopped by the second shaft portion 29 engaging the step 36 of the tubular member 18.
Since the diameter of the tubular member 18 is returned to the small diameter state by pushing the mandrel 19, the blind rivet 15 can be detached from the attaching members 38 and 39 in the assembled state in which the mandrel 19 is inserted into the tubular member 18. The attachment members can be disconnected.

Next, in the re-use, the blind rivet 15 in the assembled state in which the mandrel 19 of FIG. 8 is inserted into the tubular member 18 is disassembled to separate the mandrel 19 from the tubular member 18. Then, as shown in FIG.
Insert the tubular member 18 into the mounting holes of the mounting members 38, 39,
The mandrel 19 is pushed into the tubular member 18 as indicated by an arrow 41. This indentation is the head 21 of the mandrel 19.
Stops at a position where it engages with the protruding portion 35 of the tubular portion 16 of the tubular member 18. As a result, the connection position shown in FIG. 7 is obtained.
When removing it again from this connection position, as shown in Fig. 8,
It can be easily done by pushing in the mandrel 19.

[0016]

In the plastic blind rivet of the present invention, the tubular member and the mandrel are made of plastic, and the tubular member tubular portion can be bent so that the end portion is expanded, and the tubular member tubular portion A mandrel having a large-diameter head portion that expands the end portion and a shaft portion that extends from the head portion, in which the head portion is adjacent to the end portion of the tubular member and the shaft portion extends through the flange of the tubular member. Then, by inserting the mandrel into the tubular member and pulling out the shaft of the mandrel from the tubular member, the head expands the end of the tubular member, and by further pulling out the shaft, the shaft that comes out of the flange Since the part is formed so as to be broken, a blind rivet fastening tool can be used, and therefore, the mandrel head can be strongly pulled up into the end of the tubular member tubular part, and the connecting force, In particular, the mounting members should be pulled Even if the applied force is large, the strength of the connecting force does not change even if the thickness changes, it can respond to the change in thickness, and since the shaft part protruding from the flange is removed, the shaft part that is an obstacle Not only does it disappear, but the appearance of the mounting part also improves. Even when detaching, the mandrel shaft can be easily operated by pushing it in from the flange side.

[Brief description of drawings]

FIG. 1 shows a conventional blind rivet and its fastening operation, (A) showing a state before fastening and (B) showing a state after fastening.

FIG. 2 is a perspective view of a plastic blind rivet according to the present invention.

FIG. 3 is a front view of a blind rivet mandrel according to the present invention.

FIG. 4 is a front view, in half section, of a tubular member of a blind rivet according to the present invention.

FIG. 5 is a vertical cross-sectional view of a blind rivet according to the present invention.

FIG. 6 is a diagram showing a state before fastening of the blind rivet according to the present invention.

FIG. 7 is a diagram showing a state after fastening of the blind rivet according to the present invention.

FIG. 8 is a view showing a state where the blind rivet according to the present invention is removed.

FIG. 9 is a view showing a reuse state of the blind rivet according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conventional blind rivet 6 Tubular member 7 Mandrel 10 Small diameter part of shaft 12 Jaw of fastening tool 15 Plastic blind rivet of the present invention 16 Cylindrical part 17 Flange 18 Tubular member 19 Mandrel 21 Mandrel head 22 Mandrel shaft 23 Tip part 24 groove 25 taper part 27 small diameter part 28 first shaft part 29 second shaft part 30 third shaft part 31 breakage part 33 slit of tubular member tubular part 34 end of tubular part 35 protruding part of tubular part 38 1 Mounting member of 39 Another mounting member

Claims (3)

[Claims] 1. A hollow tubular member comprising a tubular portion and a flange, and a mandrel which is inserted into the tubular member and expands the tubular portion of the tubular member by pulling out from the tubular member. The tubular member is inserted into a mounting hole of a mounting member different from the mounting member in a state where the flange is in contact with the mounting member, and the tubular portion of the tubular member is expanded by pulling out the mandrel to expand the tubular member. In a blind rivet that interconnects the mounting members with a member portion and a flange, the tubular member and the mandrel are formed of plastic, and the tubular portion of the tubular member is divided by an axial slit. The mandrel can be bent so that the end portion expands in diameter, and the mandrel has a large-diameter head portion that expands the end portion of the tubular member tubular portion, and a shaft portion that extends from this head portion. The mandrel is inserted into the tubular member with its head adjacent the end of the tubular member and with the shank extending through the flange of the tubular member, and the shank of the mandrel is inserted into the tubular member. And a head portion that expands the diameter of the end portion of the tubular member by pulling out the shaft portion, and further that the shaft portion that comes out of the flange is broken by pulling out the shaft portion. Plastic blind rivet to be used. 2. The end of the tubular portion of the tubular member projects inward in the radial direction, and the inwardly projecting portion of the end of the tubular portion is received between the head portion and the shaft portion of the mandrel. The blind according to claim 1, wherein a small diameter portion is formed, and the small diameter portion receives the end portion of the tubular portion so as not to expand the diameter when the mandrel is inserted into the tubular member. rivet. 3. The mandrel shaft portion includes a large-diameter shaft portion that is received in the tubular portion of the tubular member, and a small-diameter shaft portion that extends from the flange of the tubular member and is gripped by a fastening tool. A blind rivet, characterized in that a small-diameter fractured portion is formed between the large-diameter shaft portion and the small-diameter shaft portion, the fractured portion being broken by the pulling-out operation of the shaft portion.