JPS6143288Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a frequency adjustment mechanism used in a cavity resonator of a high frequency circuit.

A conventional frequency adjustment mechanism of this type is constructed as shown in FIG. In Fig. 1, 1 is the main body of a semi-coaxial cavity resonator, 2 is a threaded rod for frequency adjustment, and a screw hole (not shown) is provided on one side wall of the main body 1.
One end surface of the threaded rod 2 protruding into the main body 1 faces one side surface of a protrusion 3 protruding from the other side wall of the main body 1, and a frequency adjustment is performed between them. A gap a is provided for this purpose. A nut 4 is screwed onto the other end of the threaded rod 2 protruding outside the main body 1, and a spring washer 5 is inserted between the nut 4 and the main body 1. To adjust the predetermined frequency of this cavity resonator, loosen the nut 4 and turn the threaded rod 2 to vary the gap a. After adjusting the gap a of a predetermined frequency, the nut 4 is tightened again to fix the threaded rod 2. However, at this time, the ground point (contact point) changes due to the movement of the screw rod 2 due to the pressing play of the spring washer 5 and the play in the screw hole of the main body 1 into which the screw rod 2 is screwed, and the predetermined frequency changes. Because of this, it was necessary to carry out fixing and adjustment work many times.

In view of the above-mentioned drawbacks of the conventional devices, the present invention has been developed to eliminate the change in the ground point during gap adjustment and to minimize the change in the ground point when fixing the frequency adjustment threaded rod. This is intended to provide a frequency adjustment mechanism for a cavity resonator, and its gist is that one end of a screw rod is screwed into the body of the cavity resonator to form a frequency adjustment gap, and the other end of the rod is screwed into the body of the cavity resonator. The frequency adjustment mechanism for a cavity resonator is characterized in that a knob nut is screwed together, and a spring is inserted between the main body and the knob nut.

The present invention will be described in detail with reference to the drawings below.

FIG. 2 shows an embodiment of the present invention, in which the same components as those of the conventional example are denoted by the same reference numerals. That is, 1 is the main body of a semi-coaxial cavity resonator, 2 is a threaded rod for frequency adjustment, which is screwed into a screw hole (not shown) provided in one side wall of the main body 1 so that it can move forward and backward. One end surface of the threaded rod 2 protruding inward faces one side surface of a protrusion 3 protruding from the other side wall of the main body 1, and a frequency adjustment gap a is provided between them. The above points are similar to the conventional example, but the features of the present invention are as follows. That is, a knob nut 6 is screwed onto the other end of the threaded rod 2 that protrudes outside the main body 1.
A plurality of flat springs 7 are interposed between the main body 1 and the main body 1 and are stacked one on top of the other so that a threaded rod 2 is inserted through the center of each spring.

To adjust the predetermined frequency of this cavity resonator,
First, turn the threaded rod 2 to move it forward and backward, and set the gear a.
approximately in place. Next, move the knob nut 6 toward the main body 1 side and tighten the spring 7, so that the threaded rod 2 is in a semi-fixed state (in other words, the ground point does not change). This refers to the state in which the threaded rod 2 does not move unless it is turned using a screwdriver, etc.). Next, apply a flat head screwdriver or the like to the groove 2a at the tip of the screw rod 2, turn the screw rod 2 using the flat head screwdriver or the like to move it forward or backward, set the predetermined frequency while slightly changing the gap a, and finally set the screw rod 2 to a predetermined frequency. The threaded rod 2 is completely fixed by turning the knob nut 6 and further tightening the spring 7 while preventing the rotation of the threaded rod 2 using a flathead screwdriver or the like applied to the tip groove 2a of the screwdriver.

In this way, since there is no difference in the ground point and gap between the semi-fixed state and the fixed state, a predetermined frequency can be easily determined and fixed in that state.

FIG. 3 shows a modification of the embodiment described above, in which a large-diameter rotation knob 8 is provided at the tip of the threaded rod 2, and the other configurations are the same as those of the embodiment described above. According to this modification, the frequency can be set by turning the threaded rod 2 through the knob 8 by hand without using the above-mentioned driver. Other functions and effects are the same as in the previous embodiment.

As explained above, according to the frequency adjustment mechanism for a cavity resonator according to the present invention, one end of the threaded rod is screwed into the body of the cavity resonator to form a frequency adjustment gap, and a thumb nut is attached to the other end of the threaded rod. Since they are screwed together and a counter spring is inserted between the main body and the knob nut, there is no rattling of the threaded rod unlike in conventional ones, and the ground point can be set smoothly.
It is suitable for setting a high-frequency ground point where changes in the ground point are extremely difficult. In addition, since commercially available springs can be used, this type of mechanism can be provided at low cost.
It also has the advantage that the fixing force of the threaded rod can be easily varied by changing the number of counter springs.

[Brief explanation of the drawing]

The drawings are for explaining the present invention. Fig. 1 is a schematic diagram of a conventional cavity resonator frequency adjustment mechanism, and Fig. 2 is a cavity resonator frequency adjustment mechanism showing an embodiment of the present invention. FIG. 3 is a diagram similar to FIG. 2 showing a modification of the present invention. 1... Main body of the cavity resonator, 2... Threaded rod for frequency adjustment, a... Gap for frequency adjustment, 6... Knob nut, 7... Flat spring.

Claims (1)

[Scope of utility model registration request] One end of the threaded rod is screwed into the body of the cavity resonator to form a frequency adjustment gap, and a knob nut is screwed onto the other end of the threaded rod, and a spring is inserted between the body and the knob nut. A cavity resonator frequency adjustment mechanism characterized by: