JPH0141213Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to an antenna device installed in a portable radio device (portable radio telephone, etc.) The present invention relates to an improvement in a mounting means that can be mounted selectively in any direction.

[Conventional technology]

Conventional antenna devices of this type include those shown in FIGS. 6 and 7, for example. 6th
In the figures and FIG. 7, 1 is a portable radio telephone, and the antenna mounting surface 2 of this radio telephone 1 is
An antenna attachment mechanism 3 is installed in the antenna mounting mechanism 3. This antenna mounting mechanism 3 holds the antenna 4 perpendicularly to the antenna mounting surface 2 as shown by the solid line in FIG. Hold it face down parallel to the mounting surface 2, and when using the radio telephone 1 in an upright position, hold it in a tilted position 90 degrees different from the position 4a as shown by the broken line 4b in the figure. It has become something to be gained.
In FIG. 6, 5 is a handset in the radio telephone 1, and 6 is a portable radio telephone housing case having an opening/closing lid 6a and a handle 6b. A power supply device including a converter and a transmitting/receiving circuit (both not shown) are built-in.

As shown in exploded view in FIG. 7, the antenna mounting mechanism 3 includes a first mounting block 11 fixed to the base end of the antenna 4, and a second mounting block 12 fixed to the antenna mounting surface. It is made up of. The first mounting block 11 has a cubic shape, and a coaxial power supply cable 13 is led out from the bottom surface thereof. The terminal portion of this coaxial power supply cable 13 is connected to a second mounting block 1 which will be described later.
It is connected to an antenna connection terminal (not shown) in the transmitting/receiving circuit of the radio telephone 1 through the insertion hole in 2. On the other hand, the second mounting block 12 also has a cubic shape, and an insertion hole 12a for inserting the first mounting block 11 is provided at the center of its upper end surface. Engagement grooves 12b and 12c for engaging the base end of the antenna are provided on the upper end surface of the mounting block 12 at an angle of 90 degrees with respect to each other so that one end thereof communicates with the insertion hole 12a. In addition, the insertion hole 12a
Guide grooves 12d and 12e for guiding the coaxial power cable are formed on two adjacent inner wall surfaces of the engaging groove 12.
b and 12c, respectively.

In the conventional antenna device having the above configuration, the first mounting block 11 is connected to the second mounting block 12 depending on the three states: non-use state, normal use state, and use state with the radio telephone 1 upright. By inserting it into the insertion hole 12a by changing the insertion direction by 90 degrees, it is possible to hold it in each of the states 4a, 4, and 4b in FIG. In addition, the above 4a,
4b, the base end portion 14 of the antenna 4 engages with the engagement grooves 12b and 12c, respectively, and at that time, the coaxial feed cable 13 engages with the guide groove 12.
d and 12e respectively and are guided to the wireless telephone 1.
It will be introduced into the inside of.

[Problem that the invention attempts to solve]

However, the above antenna device had the following problems. That is, when changing the antenna 4 between three states, each time the first mounting block 11 is pulled out from the insertion hole 12a of the second mounting block 12, the direction is changed, and then the first mounting block 11 is pulled out again. need to be inserted. Therefore, the operation is cumbersome, the antenna cannot be raised or lowered quickly, and it is difficult to pull out the first mounting block 11 from the second mounting block 12 and reinsert the first mounting block 11 into the second mounting block 12. When the coaxial power supply cable 13 is attached, excessive force is applied to the coaxial power supply cable 13, which may damage the coaxial power supply cable 13 or deteriorate the antenna characteristics.

Therefore, the purpose of this invention is to quickly and accurately raise and lower the antenna in at least three states (non-use state, normal use state, and use state with the radio set up), and stably over a long period of time. Provided is an antenna device for a portable radio device that can avoid applying excessive force to a coaxial feed cable when raising and lowering the antenna, and is free from the risk of damage to the coaxial feed cable or deterioration of antenna characteristics. It's about doing.

[Means for solving problems]

The present invention is characterized by taking the following measures in order to solve the above problems and achieve the objectives.

That is, the mounting base is fixed to the mounting hole provided on the antenna mounting surface of the portable radio device, with the expanding curved surface, which is expanded in a tupular shape centered on the center hole, exposed on the mounting surface. A coil spring is provided such that its proximal end is connected to the center hole of the mounting base and its distal end portion is bendable along the expansion curved surface. The base end is connected to the tip of the coil spring, and the upper end portion elastically supports the cylindrical base body so as to be able to rise and fall freely with respect to the mounting surface. A locking mechanism is provided to lock the cylindrical base body in a collapsed state on the mounting surface. A dipole antenna element is housed inside the cylindrical base. One end is connected to the feeding point of this dipole antenna element,
A coaxial power supply cable is provided such that the other end portion led out from the base end opening of the cylindrical base body is guided into the interior of the radio device through the hollow portion of the coil spring and the center hole of the mounting base.

The coil spring has a spring force strong enough to allow the cylindrical base housing the antenna element including the dipole antenna element and a part of the coaxial feed cable to stand on its own. Further, the expanded curved surface has a radius of curvature within a range that does not exceed the elastic limit of the coil spring.

[Effect]

By taking the above measures, the following effects occur.

The base end of the antenna is supported by a coil spring with sufficient spring force to allow it to stand on its own, so if the locking mechanism is released during normal use, the antenna stands on its own and is ready for use. state. When not in use or when using the radio in an upright position, the antenna is lowered in a desired direction relative to the antenna mounting surface and then locked by the locking mechanism. By doing so, it becomes possible to use the wireless device even when it is not in use or when it is upright.

The coil spring is curved along a truss-like expanding curved surface having a radius of curvature within a range that does not exceed the elastic limit of the coil spring. Therefore, there is no risk of permanent deformation of the coil spring.

Since the degree of curvature of the coil spring is restricted by the flared expansion curved surface, the coaxial power supply cable inserted through the coil spring is prevented from becoming extremely bent. As a result, it is possible to avoid applying excessive force such as extreme compressive force or tensile force to the coaxial feed cable when the antenna is raised or lowered.

〔Example〕

1 to 5 are diagrams showing an embodiment of the present invention. Note that the same parts as in FIG. 6 are denoted by the same reference numerals, and detailed explanations will be omitted. FIG. 1 is a perspective view showing a schematic configuration. In FIG. 1, an antenna device 2 is mounted on an antenna mounting surface 2 of a wireless telephone 1.
0 is set. The antenna device 20 is composed of an antenna 30 and an antenna holding mechanism 40, and the antenna 30 is held by the antenna holding mechanism 40 at an angle of 90 degrees in the directions of arrows X and Y in FIG. It is held so that it can be rotated arbitrarily in the Z direction, for example, within a range of about 90 degrees + 45 degrees, if necessary. In other words, the antenna 30
is, for example, 90°+ by the antenna holding mechanism 40.
It is maintained so that it can rise and fall freely within a range of about 45 degrees. A locking piece 21 as a locking mechanism is installed on the antenna mounting surface 2, and can lock the antenna 30 which has been operated to lie down on the mounting surface 2 in that state when not in use. In addition, 22 in FIG. 1 is a handset accommodating recess for accommodating the handset 5 (not shown).

FIG. 2 is a perspective view showing how the portable radio telephone 1 is used in an upright position. In this case, the antenna 30 is lowered in the direction of the arrow Y in FIG. The state is locked. The above-mentioned locked state is achieved by simply closing the lid 6a, and the antenna 30 is pushed down by the notch 23 on the lid 6a side, and the antenna 30 shifts to the locked state. do.

3a and 3b are diagrams showing the specific structure of the antenna device 20 together with the locking piece 21, and FIGS. 4 and 5 are diagrams showing the main attachment parts of the antenna device in an exploded manner. As shown in FIGS. 3a and 3b, 4 and 5, a locking piece 21 as a locking mechanism
is molded from a material such as synthetic resin into a substantially C-shape, and the antenna 30 can be engaged and detached from the inside of the C-shaped bent end 21a as shown by the arrow. Note that the base end 21b of the locking piece 21 is screwed onto the mounting wall 24 with a screw 25.

The antenna 30 houses a dipole antenna element 32 near the tip inside a cylindrical base 31 made of an FRP pipe, etc., and an antenna connection part 33 including an impedance matching element to this antenna element 32.
It is connected to the One end of the coaxial feed cable 13 is connected to the antenna connection portion 33 . The other end of this coaxial power supply cable 13 is led out from the base end opening of the cylindrical base 31 to the outside of the cylindrical base. A proximal columnar part 34b of a joint 34 is fitted and fixed to the distal end of the cylindrical base 31. The tip side columnar part 34 of this joint 34
A buffer cap body 35 made of a flexible member is attached to a. The buffer cap body 35 is formed by arranging a plurality of discs having different external shapes at predetermined intervals so that the overall shape is spherical. A fitting portion 36a of a joint 36 is fitted and fixed to the base end of the cylindrical base body 31. A helical groove 36b for engaging a coil spring is formed on the outer periphery of the proximal cylindrical portion of the joint 36, and the tip of a coil spring 43, which will be described later, is coupled to the helical groove 36b.

The antenna holding mechanism 40 is attached to the antenna mounting wall 24
As shown in FIG. 5, a mounting base 41 molded from synthetic resin or the like is attached to the mounting hole provided in the mounting hole, and as shown in FIG. Mounting nut with 4
2, it is fixed. The mounting base 41 has a curved surface 41a that expands in a tapered shape around the center hole, and is mounted with this expanding curved surface 41a exposed on the outer surface of the antenna mounting wall 24. As shown in the figure, a spiral groove 41b is provided on the inner peripheral surface of the center hole of the mounting base 41,
The proximal end of the coil spring 43 is screwed into this spiral groove 41b, and is coupled and fixed by inserting a bush 44 made of synthetic resin or the like. Note that the bush 44 is attached to the insertion end 4.
3a is slightly tapered, and the tail end 43b has a widened shape. coil spring 4
3 has its proximal end attached to the base 41 as described above.
is connected to the spiral groove 41b of the central hole of
It is provided so as to be bendable along a. The tip of the coil spring 43 is screwed into the helical groove 36b of the joint 36 and fixed thereto as described above.

The coil spring 43 is connected to a cylindrical base 31 that houses an antenna element including at least the dipole antenna element 32 and the coaxial feed cable 13.
However, it has a spring force that allows it to stand on its own. Further, the expanding curved surface 41a of the mounting base 41 has a radius of curvature within a range that does not exceed at least the elastic limit of the coil spring 43.

In order to obtain an expanded curved surface having such a radius of curvature, the present inventors conducted the following prototype experiment.

When a load P is applied to the center of a straight beam with a uniform cross section that is freely supported at both ends, the deflection δ is expressed by the following formula.

δ=(4PL ³ )/(3πd ⁴ E) E: Elastic modulus (Kg/mm ² ) P: Load (Kg) L: Span length (mm) d: Wire diameter (mm) δ: Deflection (mm) Also, load The maximum allowable amount P' of P is expressed by the following equation.

P′ = (πd ³ τ) / (8DK) d: Wire diameter (mm) τ: Maximum stress (Kg/mm ² ) D: Coil center diameter (mm) K: Stress modification coefficient Therefore, the following real values are Calculations were performed regarding P' and δ for the coil spring 43 having .

d=1.6 (mm), D=10.4 (mm), E=21000 (Kg/
mm ² ), K=1.2, τ=100 (Kg/mm ² ) As a result, P′≒12.88 (Kg) and δ≒1.38 (mm). Based on this, I calculated the radius of curvature of the coil spring 43 using trigonometric functions, and found that
It became 12.26 (mm). Therefore, it has been found that by providing a radius of curvature of approximately 13 (mm) or more, permanent deformation of the coil spring can be avoided.

It should be noted that the present invention is not limited to the embodiments described above, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[Effect of idea]

According to the present invention, the following effects are achieved.

The base end of the antenna is supported by a coil spring with sufficient spring force to allow it to stand on its own, so if the locking mechanism is released during normal use, the antenna stands on its own and is ready for use. state. When not in use or when using the radio in an upright position, the antenna is lowered in a desired direction relative to the antenna mounting surface and then locked by the locking mechanism. By doing so, it becomes possible to use the wireless device even when it is not in use or when it is upright. In other words, the antenna can be quickly and accurately raised and lowered into at least three states (normal use state, non-use state, and use state with the radio upright).

The coil spring is curved along a truss-like expansion curved surface having a radius of curvature within a range that does not exceed the elastic limit of the coil spring. Therefore, there is no risk of permanent deformation of the coil spring, and stable up-and-down operations can be performed over a long period of time.

Since the degree of curvature of the coil spring is restricted by the flared curved surface, the coaxial power supply cable inserted through the coil spring is prevented from becoming extremely bent. As a result, when raising and lowering the antenna, it is possible to avoid applying excessive force such as extreme compressive force or tensile force to the coaxial feed cable, minimizing damage to the coaxial feed cable and deterioration of antenna characteristics. can.

[Brief explanation of the drawing]

1 to 5 are views showing one embodiment of the present invention, in which FIG. 1 is a perspective view showing a schematic configuration, and FIG. 2 is a perspective view showing a case where the wireless telephone is used in an upright position.
3a and 3b are diagrams showing the specific structure of the antenna position together with a locking piece, and FIGS. 4 and 5 are diagrams showing the main parts of the antenna device in an exploded manner. 6 and 7 are views showing a conventional example, with FIG. 6 being a perspective view of the external appearance, and FIG. 7 being a perspective view of the antenna attachment mechanism. DESCRIPTION OF SYMBOLS 1...Portable wireless telephone, 2...Antenna mounting surface, 3...Antenna mounting mechanism, 4...Antenna, 5...Handset, 6...Accommodation case, 11...
...First mounting block, 12... Second mounting block, 20... Antenna device, 21... Locking piece, 23... Notch, 40... Antenna holding mechanism, 41... Mounting base, 42 ...Mounting nut, 43...Coil spring.

Claims (1)

[Scope of Claim for Utility Model Registration] A portable radio device is fixed to a mounting hole provided on the antenna mounting surface of a portable radio device with an expanding curved surface that expands in a shape of a flap around the center hole being exposed on the mounting surface. a mounting base, a coil spring whose proximal end is connected to the center hole of the mounting base and whose distal end portion is bendable along the expansion curved surface; and an upper end whose proximal end is coupled to the distal end of the coil spring. a cylindrical base body whose portion is resiliently supported on the mounting surface such that it can freely rise and fall; a locking mechanism that locks the cylindrical base body in a state where it lies down on the mounting surface;
A dipole antenna element housed inside the cylindrical base, one end connected to the feed point of the dipole antenna element, and the other end portion led out from the proximal opening of the cylindrical base formed in the hollow part of the coil spring. and a coaxial feed cable provided to be guided into the interior of the radio through a center hole of the mounting base, the coil spring being an antenna element including the dipole antenna element and a part of the coaxial feed cable. The cylindrical base has a spring force that allows it to stand on its own when the cylindrical base is housed, and the expanded curved surface is
An antenna device for a portable radio, characterized in that the antenna device has a radius of curvature within a range that does not exceed the elastic limit of a coil spring.