JPH0125775Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The invention consists of a leg and a head with threads formed thereon, and a washer assembly in which a washer is installed between the threads and the head bearing surface. This relates to tuft pin screws.

[Conventional technology]

Generally, the tatsu pin screw with a built-in washer that has been used conventionally is as shown in FIGS. A washer 100 is placed between the seat surface of the head 30 and the thread of the leg 20, and the washer 100 is locked with the thread, or an annular locking part 60 is provided to prevent the washer from coming off. It is designed so that it can be locked.

[Problems to be solved by the present invention] However, as shown in Fig. 5, when the washer is prevented from coming off with a screw thread, if the workpiece to which the parts are fixed is a relatively thin plate, it may be incomplete. The threaded part is screwed into this and the fully threaded part almost comes out of the workpiece, so a gap is created between the female threaded part formed by the fully threaded part of this Tatsu pin screw and the incompletely threaded part, resulting in looseness and Looseness has occurred. In addition, when a tatsu pin screw with a built-in washer shown in Fig. 6 is used to fix a relatively thin plate-like part to a workpiece, the thickness t between this part and the washer is equal to that of the tatsu pin screw's seating surface and the thread thread. If it is thinner than the distance T between the start point and the starting point, there is a problem that the part will not be fixed to the workpiece even if the tuft pin screw is tightened to the workpiece. All of this occurs because the distance T between the seat surface of the head and the starting point of the thread is wide.

Furthermore, a rounded part is usually formed on the neck to prevent it from being cut between the head and legs during tightening work, that is, to prevent so-called "neck jumping" from occurring. If the gap between the outer diameter of the leg and the outer diameter of the leg is small, there will also be a gap between the head seat and the washer. The washer becomes easy to turn together with the screw, and parts are easily damaged. On the other hand, if the inner diameter of the washer is increased in order to solve this problem, there are also problems such as the washer not being retained by the retaining portion and easily falling off.

[Means for solving problems]

The present invention was devised for the purpose of solving the above problem, and consists of a leg part 2 and a head part 3, each having a screw thread formed thereon.
In the washer-integrated tatsupin screw in which the washer 10 is installed between the seat surface of the head 3 and the seat surface of the head 3, a slope 4a is recessed inward from the seat surface and has an inverted dish shape from the outer periphery to the inner periphery. An annular groove 4 having a diameter is formed, and the inner peripheral edge of the washer 10 is loosely fitted into the groove 4.

[Effect]

A thin plate-shaped part 21 is placed on a workpiece 20, and a washer-integrated tatsu pin screw is screwed into this part 21. A washer 10 is attached to the bearing surface of this Tatsupin screw 1.
Since the inner circumferential edge of the screw 1 is loosely fitted into the annular groove 4 and covered with a washer 10 having a predetermined thickness, the incompletely threaded portion is covered with the washer 10. 21 is securely screwed in until it is in close contact.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Reference numeral 1 denotes a tatsupin screw consisting of a leg portion 2 with a thread formed thereon and a head portion 3 formed integrally with the leg portion 2, and an annular groove 4 facing inward is formed on the seat surface of the head portion 3. ing. This annular groove 4 is formed with a slope 4a that slopes from the outer periphery to the inner periphery so as to form an inverted dish shape, and the neck portion 5 of the tuft pin screw 1 is formed inside this groove 4. There is. That is, the neck 5 of this tuft pin screw 1 is connected to the head 3.
It is located inward from the seat surface. Also, this neck 5
Immediately below the leg 2, an incompletely threaded portion and a fully threaded portion are formed in succession. The distance T has almost disappeared. Therefore, this incompletely threaded portion is covered with the washer 10.

Further, the outer diameter of the annular groove 4 is larger than the outer diameter of the thread of the fully threaded portion, and the inner peripheral edge of the washer 10 is loosely fitted into the groove 4a from between this thread and the thread. . This loose fitting of the inner circumferential edge into the groove 4 is achieved by compressing the inner circumference of the washer 10 to reduce its inner diameter.

Therefore, as shown in FIG. 2, when this washer-incorporated tut pin screw is screwed in to fix the component 21 placed on the work 20 in advance, this tut pin screw 1 is screwed into the work 20 and the washer 10 is screwed in. The lower surface is in close contact with the component 21 and this component 21
to be fixed. At this time, since the incompletely threaded portion of the thread is located inward from the lower surface of the washer 10, a gap is created between the seating surface of the head 3, the washer 10, the component 21, and the workpiece 20. Never.

Next, FIGS. 3 and 4 show other embodiments of the present invention, in which an annular locking part 6 is formed in the cylindrical part directly below the seat surface, and this locking part 6 is connected to the seat surface by threading. It is provided within a distance T from the starting point of the mountain, and this distance T is
The position is set so that the thickness is within 0. The outer diameter of the annular groove 4 is larger than the outer diameter of the annular locking portion 6, and the inner circumferential edge of the washer 10 is compressed into the locking portion 6, so that the inner diameter is reduced and engaged. It will be stopped.

In this embodiment, the locking part 6 is formed into an annular shape, but this locking part 6 is for preventing the washer 10 from falling off the tatu pin screw 1, and is designed to have a continuous annular shape in this way. For example, several protrusions may be formed at intervals.

[Effect of idea]

As is clear from the above embodiments, the present invention consists of a leg 2 and a head 3 with threads formed thereon, and a washer 10 is assembled between the thread of the leg 2 and the seat surface of the head 3. In the tatsu pin screw with a built-in washer, an annular groove 4 is formed inside the seat surface of the head 3, and has a slope 4a that is recessed inward from the seat surface and has an inverted dish shape from the outer circumference to the inner circumference, This groove 4
The inner circumferential edge of the washer 10 is loosely fitted to the inner circumferential edge of the washer 10.

In this way, a groove is formed on the seat surface of the head,
Since the inner circumferential edge of the washer is pushed into this, the inner circumferential edge is securely inserted into this, and the washer does not fall out. In addition, since this groove has a slope that forms a dish shape, the flow of material during compression processing is improved, so that less pressurizing force is required. Furthermore, since the distance T between the head bearing surface of the tatsu pin screw and the thread is narrower, the incompletely threaded portion falls within the thickness of the washer, making the tatsu pin screw with a built-in washer relatively easy to use. Even when used to fix a thin plate-shaped part to a workpiece, this tuft pin screw can securely fix the part to the workpiece. Furthermore, even if the workpiece is thin, the incompletely threaded portion is not screwed into the workpiece, so there is no wobbling or loosening, and firm fixation is possible. Furthermore, since the rounded portion under the neck eliminates the formation of a gap between the head seat and the washer, extremely remarkable effects such as the screw being prevented from floating can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a partially sectional front view showing the main parts of one embodiment of the present invention, Fig. 2 is a sectional view showing the usage state of this embodiment, and Fig. 3 is a partial sectional view showing another embodiment of the present invention. FIG. 4 is a sectional view showing the usage state of this embodiment, and FIGS. 5 and 6 are sectional views showing a conventional example. 1 is a tuft pin screw, 2 is a leg, 3 is a head, 4 is a groove, 4a is a slope, 5 is a neck, 6 is a locking part, 10
is a washer, 20 is a workpiece, and 21 is a part.

Claims (1)

[Claims for Utility Model Registration] 1. A washer assembly consisting of a leg portion 2 and a head portion 3 with threads formed thereon, and a washer 10 incorporated between the threads of the leg portion 2 and the seat surface of the head portion 3. In the tatsupin screw, an annular groove 4 is formed inside the bearing surface of the head 3 and is recessed inward from the bearing surface, and the washer 1 is inserted into this groove 4.
A tatsupin screw with a built-in washer characterized by loosely fitting the inner peripheral edge of the 0. 2. The washer-integrated tatsupin screw according to claim 1, wherein the groove has a slope 4a that slopes in an inverted dish shape from the outer circumference toward the inner circumference.