JPH0728725Y2 - Retaining structure of impedance adjusting screw in high frequency coaxial line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a holding structure for an impedance adjusting screw provided on a high-frequency coaxial line.

[Conventional technology]

In a high frequency device including a coaxial line into which a high frequency is input, an impedance adjusting screw for correcting the characteristic impedance of the coaxial line may be provided. For example, a high-frequency bridge, which is a sensor for measuring the characteristics of high-frequency equipment, is used to measure the high-frequency reflection coefficient of an adapter, etc., but the high-frequency coaxial line of this high-frequency bridge is provided with an impedance adjusting screw. There is.

FIG. 3 is a sectional view of a high-frequency coaxial line provided with this impedance adjusting screw. As shown in the figure, a central conductor 4 is arranged inside the outer conductor 2 of the high-frequency coaxial line 1 with a spacer 3 interposed therebetween. The outer conductor 2 has a plurality of impedance adjusting screws 5 (hereinafter, the adjusting screw 5 at a predetermined pitch).
Also called. ) Is screwed in, and the impedance of the high frequency coaxial line 1 can be changed by adjusting the distance between the adjusting screw 5 and the center conductor 4. Therefore, in the high-frequency bridge or the like as described above, the impedance can be changed by the adjusting screw 5 according to the frequency of the input high-frequency wave, and the reference resistance value of the bridge serving as the measurement reference can be adjusted to be constant.

Then, the adjusted adjusting screws 5 are respectively held by the nuts 6, so that backlash and runout of the screws are prevented. Alternatively, as shown in FIG. 4, a spring 8 is provided between each pin 7 provided on the upper end of each adjusting screw 5 and the outer conductor 2, and each adjusting screw 5 is pressed to prevent backlash and shake. Was doing.

[Problems to be solved by the device]

According to the conventional holding structure of the impedance adjusting screw, there is a problem that the nut 6 and the spring 8 cannot be arranged when the distance between the adjusting screws 5 and 5 becomes narrow. That is, in the high frequency coaxial line, the input frequency is
As the distance increases, the distance between the adjusting screws must be narrowed. However, the conventional holding structure has a problem that it cannot cope with the increase in frequency because the distance cannot be narrowed.

Further, in the case of the holding structure using the spring 8 described above, there is a problem that the adjusting screw 5 can be adjusted only within the range in which the spring 8 can bend.

Further, in the case of the holding structure with the nut 6, it is necessary to loosen the nut 6 once when adjusting the adjusting screw 5 and set the nut 6 again after the adjustment, which causes a problem that the work is troublesome.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, according to the holding structure of the impedance adjusting screw of the present invention, the rotating peripheral surface of the plurality of impedance adjusting screws provided on the high frequency coaxial line,
The feature is that each bent spring material is locked.

[Action]

When the bent spring material is locked to the thread on the rotating peripheral surface of the impedance adjusting screw, a load due to the reaction force of the spring material is applied to the peripheral surface, and backlash and runout of the impedance adjusting screw are prevented.

〔Example〕

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a sectional view thereof. It should be noted that the same components as those of the related art are denoted by the same reference numerals as those in FIG. 3, and the description thereof will be omitted.

The outer conductor 12 of the high-frequency coaxial line 11 is provided with a plurality of impedance adjusting screws 13 at narrow intervals so that the nut 6 and the spring 8 as the holding means described above cannot be provided.
Then, in the screw portion 14 formed on the peripheral surface of the impedance adjusting screw 13, two spring members 15 and 15 are bent in a wavy manner so as to sew each adjusting screw 13. It is installed. With such a structure, the two bent spring members 15 and 15 apply a reaction force in opposite directions to each adjusting screw 13, so that each adjusting screw 13 is surely fixed by the two spring members 15 and 15. It is pinched. Therefore, each adjustment screw 13 has no backlash and no runout. Further, since each adjusting screw 13 is held by being pressed by the reaction force of the bent spring member 15, the adjusting screw 13 can be adjusted in this state, and the spring member 15 is attached or detached. It doesn't take much time.

In this embodiment, two spring members 15 and 15 are used, but the same effect can be obtained even if only one spring member is used. Particularly when a large number of adjusting screws 13 are arranged in a row, one spring material can exert a sufficient holding effect. Also, three or more spring members may be used depending on the required holding force. Adjustment screw
When the number of springs 13 is one or two, by locking the end of the spring material 15 with some fixing member other than the adjusting screw 13,
It is preferable that the bent spring material 15 is locked to the adjusting screw 13 at a portion other than the end portion.

Further, in the present embodiment, the spring member 15 is configured to be locked to the screw portion 14 formed on the peripheral surface of the adjusting screw 13, and the thickness of the spring member 15 is set to the dimension (pitch) of the ridges and valleys of the screw portion 14. If they match,
Since the spring material 15 once locked does not shift or come off, it can be held more reliably.

[Effect of device]

According to the present invention, the adjusting screw is held by locking the bent spring member on the peripheral surface of the adjusting screw. Therefore, according to the present invention, it is possible to securely hold the adjusting screws with a narrow gap, which cannot be applied to the conventional holding structure such as the nut or the spring, by semi-fixing so as to prevent backlash and runout. Further, the adjusting screw held semi-fixedly can be easily rotated in the state as it is, and the impedance can be adjusted.

[Brief description of drawings]

1 is a plan view showing an embodiment of the present invention, FIG. 2 is a sectional view of the same, FIG. 3 is a sectional view showing a conventional structure for holding an impedance adjusting screw, and FIG. 4 is another conventional holding structure. FIG. 11 ... High-frequency coaxial line, 13 ... Impedance adjusting screw (adjusting screw), 14 ... Screw portion as peripheral surface, 15 ... Spring material.

Claims (1)

[Scope of utility model registration request] 1. A holding structure for an impedance adjusting screw in a high-frequency coaxial line, characterized in that flexed spring members are respectively locked to the rotating peripheral surfaces of a plurality of impedance adjusting screws provided in the high-frequency coaxial line.