JPS6342574Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a nut for fixing a rod-shaped telescoping antenna to, for example, the fender of an automobile, and more particularly to a waterproof nut in which a waterproof cap is attached to the top of the nut body.

Antennas installed in automobiles, etc. generally have a rod-shaped antenna element that can be inserted and removed freely into a storage tube installed inside the vehicle body. The problem is that rainwater and the like can enter through the gaps, causing various problems. One solution to this problem is to install a waterproof cap on the top of the antenna fixing nut to prevent rainwater from penetrating into the housing cylinder through the outer circumferential surface of the antenna element. It is being However, conventional waterproof nuts have a structure in which the flange provided on the outer periphery of the base end of the waterproof cap is locked by caulking at the top of the nut body.
In addition to problems such as the plating peeling off or cracking, there were also problems such as large variations in the dimensions of the finished product, which hindered the insertion and removal of the antenna element.

This idea was devised in consideration of these circumstances, and its purpose was to allow the cap to be easily and securely attached by simply pushing the waterproof cap into the top of the nut body. There is no need for plating peeling or cracking, there is almost no variation in the dimensions of the finished product, there is no risk of interfering with the operation of inserting and removing the antenna element, and it is highly waterproof, and the cap is not exposed. To provide a waterproof nut for fixing a rod-shaped telescoping antenna, which has an extremely small portion, is pleasing in appearance, and has excellent mechanical strength.

An embodiment of this invention will be described below with reference to the drawings. Fig. 1 is a diagram showing the external appearance of an embodiment in which the nut of the present invention is applied to an automobile antenna. 1 is a rod-shaped telescopic antenna in which a plurality of conductive tubes 1a, 1b, and 1c of different diameters are slidably connected to each other. The device is designed to be removably inserted into a storage cylinder 2 installed inside the vehicle body. Reference numeral 3 designates a lower mounting element mounted near the top of the storage tube 2, which comes into contact with the back surface of the vehicle body wall 4 to form a grounding circuit. Reference numeral 5 designates an upper mounting element, which is fitted into a part of the storage tube 2 protruding outward from the vehicle body through a mounting hole in the vehicle body wall 4, and one end thereof is brought into contact with the surface of the vehicle body wall 4.
6 is a fixing nut, which is attached to the upper mounting element 5
The antenna is screwed into a part of the housing tube 2 (usually a conductive tube that is inserted into the housing tube to establish electrical continuity with the antenna element 1) that protrudes outward through the fitting hole, and the entire antenna is used as a mounting base. It is fixed to the vehicle body wall 4.

FIG. 2 is a side view showing half of the fixing waterproof nut 6 cut away. In FIG. 2, 10 is the nut body, and 20 is a waterproof cap.
The nut body 10 is made of metal such as brass, and has a surface plated with Cr plating or the like. A tightening flange portion 11 is formed at the center of the outer periphery of the nut body 10, and a threaded portion 12 is screwed from the open end on the bottom side of the inner circumferential surface to approximately the center portion. As clearly shown in FIG. 3, a funnel-shaped guide portion 13 is provided at the open end of the nut body 10 on the top side. An annular locking recess 14 is formed in the circumferential direction of the inner circumferential surface at a position slightly shifted toward the back from the guide portion 13 . The waterproof cap 20 is made of a highly waterproof flexible material such as soft synthetic resin and is formed into a substantially cylindrical shape. As clearly shown in FIG. 3, an annular locking protrusion 21 is provided on the outer periphery of one end of the cap 20 with a reduced wall thickness, and is recessed into the locking recess 14 of the nut body 10. engaged. A tongue portion 22 is provided on the inner circumferential edge of the other end of the waterproof cap 20 so as to protrude so that the wall thickness gradually decreases in the axial direction. This tongue portion 22 is adapted to slide in liquid-tight contact with the outer peripheral surface of the maximum diameter tube 1c of the antenna element 1. In addition, the inner diameter of the waterproof cap 20 is gradually increased toward one end where the locking projection 21 is provided on the inner circumferential surface of the waterproof cap 20 so that only the tongue portion 22 comes into sliding contact with the outer circumferential surface of the element. Tapered surface 23
has been established.

Next, the operation of the nut constructed as described above will be explained. First, in order to attach the waterproof cap 20 to the nut body 10, the cap 20 is pushed into the top of the nut body 10 as shown by the arrow in FIG. Then, the locking protrusion 21 of the cap 20
The opening on the side where the nut body 10 is provided is gradually compressed and narrowed by the funnel-shaped guide portion 13 of the nut body 10, and then slides into the nut body 10. Finally, the locking protrusion 21 fits into the locking recess 14. At this time, since the waterproof cap 20 is made of a flexible material and the thickness of the peripheral wall at one end where the protrusion 21 is provided is small,
The above-mentioned engaged state is achieved relatively easily. In this engaged state, the bulging outer circumferential surface near the other thick end of the cap 20 is just accommodated within the funnel-shaped guide portion 13 of the nut body 10.
Only a small portion including the tongue portion 22 is exposed to the outside of the nut body 10.

Thus, when the antenna is fixed using the waterproof nut, the tongue portion 22 of the cap 20 comes into liquid-tight sliding contact with the circumferential surface of the rod-shaped antenna element 1. At this time, the axis of the waterproof cap 20 is precisely aligned with the nut body 10, and there is no inclination at all, and the thickness of the tongue portion 22 is small, making it extremely flexible. Rich. Therefore, it comes into uniform sliding contact with the outer peripheral surface of the antenna element. Therefore, it is possible to smoothly insert and remove the antenna element 1, and
Rainwater or the like that attempts to enter the housing tube 2 through the outer peripheral surface of the antenna element is reliably blocked by the tongue portion 22 of the waterproof cap 20. Note that the upper end of the cap that is exposed outward from the top of the nut body 10 is very small, which is preferable in terms of appearance. Moreover, in terms of mechanical strength, most of the nut body 10
It is not easily damaged because it is in a protected form.

Note that this invention is not limited to the embodiments described above. For example, the locking projections 21 of the waterproof cap 20 do not necessarily have to be annular, but may be scattered around the outer circumference of the cap. Alternatively, a slit parallel to the axis may be provided at one end of the waterproof cap 20 with a reduced wall thickness so that the one end is easily compressed when press-fitting into the nut body 10. Of course, various other modifications can be made without changing the gist of the invention.

As explained above, the present invention provides the following effects.

The nut body is provided with a funnel-shaped guide,
Since the locking projection of the waterproof cap is formed on the outer periphery of the lower end portion with a reduced thickness, the nut body and the waterproof cap can be easily integrated by simply pushing the waterproof cap into the nut body from the upper end opening of the nut body.
Therefore, the assembly is easy and the nut body does not peel off or crack due to the conventional crimping process of the nut body.

The engagement between the locking recess provided on the inner peripheral surface of the nut body and the locking protrusion provided on the outer periphery of the lower end of the waterproof cap, and the engagement between the funnel-shaped guide portion of the nut body and the bulged outer peripheral surface of the waterproof cap. Due to the close contact between the nut body and the waterproof cap, the nut body and the waterproof cap are stably integrated without wobbling. Therefore, there is almost no variation in the dimensions of the finished product, and there is no risk of interfering with the operation of inserting and removing the antenna element.

The tongue portion of the waterproof cap has a wall that gradually becomes thicker in the axial direction at the junction between the upper end of the inner peripheral surface, which gradually becomes smaller in diameter from the lower end opening to the upper end opening, and the upper end of the outer peripheral surface. Since the tongue piece protrudes to be small in size, the tongue piece slides into liquid-tight contact with the outer circumferential surface of the antenna element with extremely high precision. Therefore, an excellent waterproof effect can be exhibited.

The waterproof cap and the nut body are integrated in such a way that almost the entire waterproof cap is buried within the nut body, leaving a part of the upper end of the waterproof cap, so the exposed part of the waterproof cap is minimized and the appearance is improved. In addition to being preferable, it also has excellent mechanical strength.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of this invention.
FIG. 2 is a side view showing the nut of the same embodiment, cut in half, and FIG. 3 is a sectional view of the essential parts of the nut of the same embodiment, separated into a nut body and a waterproof cap. DESCRIPTION OF SYMBOLS 1... Rod-shaped telescopic antenna element, 2... Storage tube, 6... Waterproof nut for fixing, 10... Nut body, 11... Flange part for tightening, 12... Threaded part, 13... Funnel-shaped guide 14...Latching recess, 20...Waterproof cap, 21...Locking protrusion, 22...Language portion, 23...Tapered surface.

Claims (1)

[Scope of Claim for Utility Model Registration] A nut body that is screwed into the element insertion/removal opening of a storage tube for removably storing a rod-shaped antenna element and fixing the entire antenna to the mounting base, and a nut body that is installed inside the nut body. and a cylindrical waterproof cap made of a waterproof flexible member, the nut body having a funnel-shaped guide portion formed at the upper end opening portion, and an inner circumferential surface of a portion below the funnel-shaped guide portion. The waterproof cap is provided with a ring-shaped locking recess formed along the circumferential direction, and the waterproof cap is formed on the outer periphery of the lower end portion with a reduced wall thickness and is guided to the funnel-shaped guide portion of the nut body. and a locking protrusion that is inserted into the locking recess and engaged with the locking recess, and when the locking protrusion is recessed and engaged with the locking recess, a portion of the locking projection is engaged with the funnel-shaped guide part. The outer circumferential surface bulges out so that it fits tightly,
An inner peripheral surface whose diameter gradually decreases from the lower end opening to the upper end opening, and a wall thickness that gradually decreases in the axial direction at the connection point between the upper end of this inner peripheral surface and the upper end of the outer peripheral surface. a tongue protruding from the top of the nut body and slidingly contacting the outer circumferential surface of the antenna element in a liquid-tight manner; A waterproof nut for fixing a rod-shaped telescopic antenna, characterized by an integrated cap and nut body.