JPH0445205Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a semi-fixed variable resistor, and particularly to an adjustment knob for adjusting the resistance value from the back side.

[Prior Art] Many semi-fixed variable resistors have been known in the past, in which a slider piece rotates and slides on a resistance layer formed on the surface of an insulating base to change the contact position to obtain a desired resistance value. It is being This type of semi-fixed variable resistor is attached to a printed wiring board,
After it is connected to the electric circuit, the resistance value is finely adjusted from the outside using an adjustment jig such as a screwdriver, so a groove for engaging the jig is formed at one end of the adjustment knob fixed to the slider piece. has been done.

FIG. 5 shows an example of a conventional semi-fixed variable resistor, in which a resistance board 2 whose surface is coated with a ring of electrical resistance material is housed in the bottom of an insulating case 1. One end 3a of a slider piece 3 made of a conductive spring material is in elastic contact with. This slider piece 3 is fixed to a first adjustment knob 4 that is rotatably attached to the insulating case 1, and when the adjustment knob 4 is rotated, one end 3a is attached to the resistor board 2.
slide on top. In addition, a second adjustment knob 5 is rotatably attached to the opposite side of the insulating case 1 from the side where the first adjustment knob 4 is attached. In this case, the slider piece 3 is fixed. Therefore, the second adjustment knob 5
When rotated by a jig, the slider piece 5 slides on the resistor board 2 in the same manner as described above.

The first and second adjustment knobs 4 and 5 have grooves 4a and 4a, respectively, which can be engaged with a jig such as a screwdriver.
5b is formed, and when the variable resistor is attached to the printed wiring board 6 at the position indicated by the two-dot chain line in the figure, the groove 4a is formed whether from the front or back side of the printed wiring board 6. , 5b, the resistance value can be adjusted. Further, 7 and 8 in the figure are terminals connected to both terminals of the resistance board 2.

[Problem that the invention attempts to solve]

By the way, in the case of the above-mentioned semi-fixed variable resistor, the second adjustment knob 5 is formed by so-called header processing, in which material is put into a mold and tapped to form a desired shape. However, continuous machining was not possible and machining efficiency was low.

Therefore, for the purpose of improving machining efficiency, the present applicant developed a flange-like plate material having a shaft portion 5a and a groove 5b.
We previously filed an application for an adjustment knob for a semi-fixed variable resistor that was made by folding and integrating a flange-like plate material with According to this earlier application, since the second adjustment knob can be formed by press working using a metal plate, automation is realized and it is an extremely effective means for improving the production industry, but it is not without problems. do not have. That is, since the wall thickness of the flange-shaped plate material having the groove 5b is thin, when a jig such as a driver is engaged with the groove 5b and the second adjustment knob 5 is rotated, the connecting portion ( There is a problem that the folded part) is easily deformed. especially,
As semi-fixed variable resistors become smaller, the width and thickness of the connecting portions also become smaller, and this tendency becomes more pronounced.

Therefore, an object of the present invention is to provide a semi-fixed variable resistor that can continuously form an adjustment knob for adjusting the back side by press working, and is equipped with an adjustment knob that has sufficient strength during adjustment. .

[Means for solving problems]

In order to achieve the above object, the present invention includes a substrate on which a resistance layer is formed, a first adjustment knob provided with a slider piece that can slide on the resistance layer, and a first adjustment knob provided on the substrate. The slider piece includes a shaft portion inserted through the shaft portion and a second adjustment knob having a flange extending from the shaft portion, and the slider piece rotates and slides on the resistance layer to change the contact position. In the semi-fixed variable resistor that can obtain a resistance value, the second adjustment knob has a first flange portion extending from one end of the shaft portion and having a locking claw bent and formed on the periphery; A second flange is folded onto the first flange portion via a connecting portion, has a notch portion on its periphery that engages with the locking pawl, and has a slit in the center that can engage the adjustment jig. and a stopper portion for regulating the rotation angle of the second adjustment knob is formed on the periphery of at least one of the first and second flange portions. .

[Effect]

That is, according to the above means, the first flange portion having the shaft portion and the second flange portion having the adjustment slit are connected not only to the folded portions of both but also to the locking pawls and notches provided on the respective peripheries. Therefore, when the adjustment jig is engaged with the slit and the second adjustment knob is rotated, further rotational force is applied especially after the rotation is restricted by the stopper part. When applied, the strength in the rotational direction is significantly improved.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 4.

First, the configuration of a semi-fixed variable resistor according to an embodiment of the present invention will be explained using FIGS. 3 and 4. In these figures, reference numeral 9 indicates a second adjustment knob for adjusting the back surface, and the second adjustment knob 9
is made of a single metal plate, and includes a hollow shaft portion 9a whose one end is caulked and fixed to the slider piece 3, a first flange portion 9b provided at the other end of the shaft portion 9a, and a first flange portion 9b provided at the other end of the shaft portion 9a. The second plate folded and stacked on the flange portion 9b of
flange portion 9c. The first flange portion 9b has locking claws 9d bent toward the second flange portion 9c at three locations on its circumference, and the second flange portion 9c has locking claws at three locations on its circumference. It has a notch 9e that engages with the notch 9d, a rectangular slit 9f at its center, and flange-like stoppers 9g at two locations around its periphery. On the other hand, one cut-and-raised piece 7a is provided near the bent portion of the terminal 7, and this cut-and-raised piece 7a is located within the rotation locus of the stopper portion 9g. Therefore, the slit 9f of the second adjustment knob 9
When a jig such as a driver is engaged and rotated, the rotational force is applied to the first and second flange portions 9.
Folding portion 9h between b and 9c and three locking claws 9d
is transmitted to the first flange portion 9b via the first flange portion 9b, and further to the slider piece 3 fixed to the tip of the shaft portion 9a via the shaft portion 9a integrally formed with the first flange portion 9b. As a result, the slider piece 3 slides on the resistor board 2. Also, at this time, the second adjustment knob 9
The rotation angle is regulated by one of the stopper portions 9g colliding with the cut-and-raised piece 7a of the terminal 7. Note that the other configurations are the same as those of the conventional example shown in FIG. 5, so detailed explanations will be omitted by giving the same reference numerals.

Next, a method of manufacturing the second adjustment knob 9 will be explained with reference to FIGS. 1 and 2.

First, a hoop-shaped metal plate having a predetermined thickness is press-formed to form a drawn hollow shaft portion 9a as shown in FIG. 1, and a flat plate portion extending perpendicularly to the shaft portion 9a. This flat plate part and the peripheral edge 3
The first flange portion 9b has locking claws 9d at several locations.
and a second flange part 9c which has three notches 9e and two stopper parts 9g on the periphery and a rectangular slit 9f in the center, and the width between these two flange parts 9b and 9c is connected by a narrow part.

Next, the flat plate part is folded in the direction of the arrow along the line A--A in FIG. 1, and the second flange part 9c is superimposed on the first flange part 9d. Thereafter, as shown in FIG. 2, each of the locking claws 9d is bent toward the second flange portion 9c, and these locking claws 9d are engaged with each of the notches 9e. As a result, the second adjustment knob 9 is formed, which includes a flange having a thickness twice that of the metal plate and a shaft portion 9a extending perpendicularly from the flange.

The second adjustment knob 9 formed in this way
As mentioned above, the flange part 9 has two flanges.
The flange portions 9b and 9c have a thick wall structure by folding the flange portions 9b and 9c, and the flange portions 9b and 9c are overlapped with the respective locking claws 9d and notches 9e, so that they can be easily used with tools such as screwdrivers. Slit the ingredients 9F
It is sufficiently strong against the rotational force when the second adjustment knob 9 is rotated by inserting it into the body, and there is no problem that the folding portion 9h is deformed during the rotation operation. In particular, each locking pawl 9d and notch 9e are formed on the periphery of the first and second flange parts 9b, 9c, and are located sufficiently away from the slit 9f formed in the center of the second flange part 9c. Therefore, even if the jig is further rotated after the rotation of the second adjustment knob 9 is regulated by the collision between the stopper portion 9g and the cut-and-raised piece 7a, the rotational force will cause each locking Deformation of the claw 9d can be suppressed as much as possible, and from this point of view as well, the folded portion 9h is difficult to deform. Further, a locking pawl 9 is provided on the first flange portion 9b side having the shaft portion 9a.
d is a second flange portion 9 having a slit 9f.
Since the cutout portion 9e is formed on the c side, even if the tip of the bent locking claw 9d protrudes from the surface of the second flange portion 9c, rotational operation will not be hindered, and therefore, the locking claw 9d The engagement between the notch portion 9e and the notch portion 9e can be ensured. Further, since each notch 9e is formed at the periphery of the second flange 9c and has an open outward shape, the second flange 9c
After folding against the first flange portion 9b, each locking pawl 9d can be bent from the open end side of the corresponding notch 9e to engage the two, which also increases productivity. be able to.

In addition, in the above embodiment, a case was explained in which three locking claws 9d formed at approximately 90-degree intervals and three notches 9e formed at approximately 90-degree intervals, but these locking claws The number and formation positions of the cutout portions 9d and 9e can be changed as necessary.

[Effect of idea]

As explained above, according to the present invention, the shaft part, flange, slit for rotation operation, etc. necessary for the adjustment knob for adjusting the back side can be continuously machined from a single metal plate by press forming. In addition, the strength of the flange in the rotational direction can be increased by engaging the locking claws formed on the periphery of each of the two flange-like plates with the notch,
Therefore, it is possible to provide a semi-fixed variable resistor that is excellent in mass production and allows for reliable adjustment work.

[Brief explanation of the drawing]

1 to 4 relate to an embodiment of the present invention, in which FIG. 1 is a perspective view showing the second adjustment knob in an expanded state, FIG. 2 is a perspective view of the second adjustment knob, FIG. 3 is a sectional view of a semi-fixed variable resistor, FIG. 4 is a bottom view of the semi-fixed variable resistor, and FIG. 5 is a sectional view of a conventional semi-fixed variable resistor. 2... Resistance board, 3... Slider piece, 4... First
Adjustment knob, 7, 8...terminal, 9...second adjustment knob, 9a...shaft, 9b...first flange, 9c...second flange, 9d...locking claw , 9e...notch, 9f...slit, 9g...
...Stopper part, 9h...Folding part.

Claims (1)

[Scope of utility model registration request] A substrate having a resistance layer formed on its surface, a first adjustment knob provided with a slider piece that can slide on the resistance layer, a shaft inserted through the substrate, and a shaft extending from the shaft. and a second adjustment knob having a flange, the slider piece rotates and slides on the resistance layer to change the contact position, thereby obtaining a desired resistance value. , the second adjustment knob extends from one end of the shaft,
and a first flange portion having a locking pawl bent and formed on the peripheral edge, and a notch portion that is folded on the first flange portion via a connecting portion and engages with the locking pawl on the peripheral edge. a second flange portion having a slit in the center that can be engaged with an adjustment jig; and a second adjustment knob on the periphery of at least one of the first and second flange portions. A semi-fixed variable resistor characterized by forming a stopper portion for regulating the rotation angle of the variable resistor.