JP2546617Y2 - Ground structure of turntable for electromagnetic wave measurement - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION In this invention, an electronic device to be measured is mounted and rotated, and a metal turntable used for measuring an electromagnetic wave radiated from the electronic device to be measured is grounded to a ground plane. Related to the grounding structure.

[0002]

2. Description of the Related Art As shown in FIG. 3, a ground plane 11 made of a metal plate is used for measuring whether or not an obstacle radio wave radiated to the outside of an electronic device is within a standard or for measuring directivity of an antenna.
A turntable 12 made of metal is rotatably provided thereon, and an electronic device 13 to be measured is mounted on the turntable 12, while an antenna 14 is provided on the ground plane 11, and the electronic device to be measured is The electromagnetic wave radiated from 13 is received and its level is measured. By performing the above measurement while rotating the turntable 12, the electromagnetic waves radiated from each direction of the electronic device 13 to be measured can be measured.

In this case, unless each part of the turntable 12 is set to the same potential as the ground plane 11,
The electromagnetic wave radiated from 3 is re-radiated from the turntable 12 and correct measurement cannot be performed. Therefore, the turntable 12 is grounded to the ground plane 11 by the ground structure shown in FIG. The electronic device under test 13 mounted on the turntable 12 may be as heavy as several hundred kg. For this reason, the radially and circumferentially reinforcing ribs 16 are fixed to the bottom surface of the turntable 12, and the reinforcing ribs 16a near the outer edge of the turntable 12 are particularly thick. The load receiving bearing 17 is rolled and contacted with the fixed portion via the bearing 17. In order to prevent the entire turntable 12 and its rotating shaft from acting as an antenna, it is desirable to ground the outer periphery of the turntable 12 as much as possible. The rib 16
In order not to obstruct the load receiving bearing 17 and its holding mechanism, the bottom surface of the outer peripheral reinforcing rib 16a is electrically connected to the ground plane 11 through the ground mechanism 18 to ground the turntable 12. . Grounding mechanism 18
For example, one end of a contact piece 18a made of a metal spring material is brought into sliding contact with the bottom surface of the rib 16a, and the other end is made of a metal support 1
8b, and the metal support 18b is fixed to the ground plane 11.

[0004]

While the rotation of the turntable 12 is repeated, the load receiving bearing 17
And the ribs 16a are displaced from each other in a state where they come into contact with each other with a strong force, and the bottom surface of the ribs 16a is roughened, and the grounding mechanism 18 contacts the roughened surface. The electrical contact of the turntable 12 becomes worse, and the stable grounding of the turntable 12 cannot be expected.

If the grounding mechanism 18 is brought into contact with the outer peripheral surface of the rib 16a, there is no problem of the deterioration of the smoothness of the contact surface. The turntable 12 is detached for repair and inspection of the turntable drive mechanism, and the subsequent turntable mounting work becomes extremely difficult.

[0006]

According to the first aspect of the present invention, a ring-shaped metal fitting concentric with the turntable is mounted near the outer peripheral portion of the turntable and is electrically integrated with the turntable. The grounding mechanism is brought into contact with the bottom surface of the metal fitting and grounded on the grounding surface. According to the invention of claim 2, a ring-shaped grounding fitting concentric with the turntable is provided below the turntable near its outer periphery, and the grounding fitting is electrically connected to a ground plane. A grounding mechanism that is in contact with the upper surface of the grounding bracket is attached to the turntable and is electrically connected.

[0007]

FIG. 1 shows an embodiment of the present invention. Near the outer periphery of the turntable 12, a ring-shaped metal fitting 21 concentric with the turntable 12 is attached and is electrically connected to the turntable 12. For example, the outer peripheral reinforcing rib 1
A ring-shaped grounding metal fitting 21 is disposed concentrically with the inner peripheral surface of 6a, and the upper surface of the grounding metal fitting 21 and the inner peripheral surface of the outer peripheral reinforcing rib 16a are fixed to each other by L metal fittings 22. Is done. Although not shown in the figure, the grounding dedicated metal fitting 21 is not so much lower than the rib 16a as not to interfere with the load receiving bearing 17 and its holding portion. L bracket 2
For example, 2 is fixed to the metal fitting 21 only for grounding by welding, and is fixed to the rib 16a by screws. As the grounding metal fitting 21, stainless steel or the like is preferable from the viewpoint of rust prevention, and a plate ring-shaped body whose bottom surface is made as smooth as possible is preferable.

[0008] A grounding mechanism 23 is provided in contact with the bottom surface of the grounding metal fitting 21, and the grounding metal fitting 21 is grounded (electrically connected) to the ground plane 11 through the grounding mechanism 23.
In this example, the grounding mechanism 23 is fixed to the ground plane 11 and electrically connected thereto, and a support 23a is provided. The arm 23b is rotatably attached to the support 23a, and a ball bearing is provided at an end of the arm 23b. 23c is rotatably mounted, the outer peripheral surface of the outer ring of the ball bearing 23c is rolled into contact with the bottom surface of the grounding metal fitting 21, one end of the conductive spring piece 23d is fixed to the support 23a, and the other end is a ball. The ball bearing 23 c is pressed against the outer peripheral surface of the outer ring of the bearing 23 c and pressed against the metal fitting 21 for grounding.

The turntable 12 is electrically connected to the ground plane 11 through the ribs 16a, the L metal fitting 22, the grounding metal fitting 21, the ball bearing 23c, the spring piece 23d, and the support 23a to be grounded. Since the load receiving bearing is not in contact with the grounding metal fitting 21, the grounding metal fitting 2
The bottom surface of 1 is not strongly rubbed, a smooth state is maintained, and good electrical contact with the grounding mechanism 23 is maintained for a long time.

As the grounding mechanism 23, one similar to the conventional one shown in FIG. 4 or another one may be used. Further, the metal fitting 21 for grounding may be attached near the outer peripheral surface of the rib 16a. FIG. 2 shows an embodiment of the invention of claim 2, in which parts corresponding to those in FIGS. 1 and 4 are denoted by the same reference numerals. In this example, the rib 1 is located slightly outside the area immediately below the outer peripheral reinforcing rib 16a.
A ring-shaped grounding metal fitting 24 concentric with 6a is arranged. The grounding metal fitting 24 is, for example, a plate-like ring made of stainless steel, and is supported and electrically connected to the ground plane 11 by a metal support piece 25. The upper surface of the grounding metal fitting 24 is a smooth surface. A grounding mechanism 26 in contact with the upper surface of the grounding bracket 24 is attached to the turntable 12 and is electrically connected. In this example, the conductive spring piece 2 is used as the grounding mechanism 26.
6d is brought into pressure contact with the upper surface of the grounding bracket 24,
The L fitting 26b is attached to the outer peripheral surface of the rib 16a, and the other end of the conductive spring piece 26a is fixed to the L fitting 26b.

The turntable 12 is electrically connected to the ground plane 11 through the ribs 16a, the L fittings 26b, the conductive spring pieces 26a, the grounding fittings 24, and the support pieces 25, and is grounded. As the grounding mechanism 26, one similar to that shown in FIG. 1 or another one may be used. When holding the load receiving bearing 17 outside the turntable 12,
The grounding metal fitting 24 is set inside the rib 16a.

[0012]

As described above, according to the present invention, the grounding fittings 21 or 24 used only for grounding,
Since the turntable 12 is grounded by using the grounding mechanism 23 or 26, even when used for a long period of time, the contact surface between the grounding mechanism and the grounding bracket is not likely to be rough, and good electrical contact is obtained. , The turntable 12 is stably grounded. Since the grounding metal fittings 21 or 24 may be thin, even if an expensive stainless steel or the like that does not easily rust is used, the whole is not so expensive, and more stable grounding can be achieved. Also, this grounding structure does not hinder the mounting of the turntable.

[Brief description of the drawings]

FIG. 1 is a partially broken perspective view showing a part of an embodiment of the invention of claim 1;

FIG. 2 is a partially broken perspective view showing a part of the embodiment of the invention of claim 2;

FIG. 3 is a diagram showing a configuration of electromagnetic wave measurement of a device using a turntable.

FIG. 4 is a partially broken perspective view showing a part of a conventional turntable grounding structure.

Claims (2)

(57) [Scope of request for utility model registration] 1. A ring-shaped grounding-only bracket concentric with the turntable and electrically attached to the turntable near the outer periphery of the turntable and in electrical contact with the bottom surface of the grounding-only bracket. And a grounding mechanism for grounding the grounding surface on a grounding surface. 2. A ring-shaped grounding member provided on the lower side of the turntable near the outer peripheral portion thereof and electrically connected to a grounding surface and concentric with the turntable, and an upper surface of the grounding member. A grounding mechanism for an electromagnetic wave measuring turntable, comprising: a grounding mechanism that is in electrical contact with, electrically connected to, and attached to the turntable.