JPH0950906A - High-voltage variable resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-voltage variable resistor in which soldering operations at the time of mounting a high-voltage variable resistor on a flyback transformer can be reduced and the dimension of the projection of the high- voltage variable resistor which projects from the flyback transformer can be reduced. SOLUTION: A circuit board 5 is housed in the opening of an insulating case with one end opened. A connection terminal 8 projects from the rear side of the circuit board 5. A cylinder 7b projects from the opening of the insulating case 1 beyond an insulating resin layer 6 surrounding the connection terminal 8 and provided in the rear of the circuit board. A connection terminal part 7 is formed by fitting into the cylinder 7b a terminal plug-in part 7c made of electrically conductive rubber into which the connection terminal 8 is inserted. The connection terminal part 7 is projected from the opening of the insulating case through the insulating resin layer 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high voltage variable resistor fixed to a flyback transformer via a molding resin.

[0002]

2. Description of the Related Art Conventionally, many high voltage variable resistors fixed to a flyback transformer via a molding resin have been proposed. The general structure of this high-voltage variable resistor is that the operating axis of the variable resistor projects from the front part of the insulating case, and the opening side that opens to the side opposite to the front part is fixed to the flyback transformer via the molding resin. Is to be done. The position of the output terminal is determined according to the circuit configuration and the mounting mode, but most of the high-voltage variable resistors have some terminal on the opening side.

[0003]

The terminals provided on the side of the opening covered with the mold resin are soldered to the ends of the lead wires and the connecting conductors connected to the flyback transformer. However, the soldering work is a troublesome work, and there is a demand to reduce the soldering work as much as possible. In addition, when the connection part is configured by soldering, excessive force is applied to this connection part when filling the mold resin when mounting the high-voltage variable resistor in the flyback transformer or when the mold resin cures. There is a problem of disconnection.

An object of the present invention is to attach a high-voltage variable resistor to a flyback transformer without requiring an unreasonable force such as a break in the connecting portion of the terminals because the terminals can be easily connected. A high-voltage variable resistor that can reduce the soldering work for the high-voltage variable resistor that does not need to be thickened in the insulating case and can reduce the protrusion size of the high-voltage variable resistor protruding from the flyback transformer. To provide.

[0005]

According to the present invention, an insulating case 1 in which a circuit board 5 having a resistor circuit pattern is open at one end is provided.
Is accommodated in the opening of the insulating case, the slider is accommodated between the insulating case and the surface of the circuit board, and the insulating resin is filled in the opening of the insulating case so as to cover the back surface of the circuit board.
Is formed, the connection terminal 8 is provided so as to project from the back surface side of the circuit board, and the connection terminal portion 7 for electrically connecting the connection member extending from the flyback transformer to the connection terminal 8 is provided on the back surface of the circuit board. The target is a high-voltage variable resistor fixed to the side. In the present invention, the cylindrical portion 7b is provided so as to surround the connection terminal 8 and extend beyond the insulating resin layer 6 so as to project from the opening of the insulating case 1, and the connection terminal 8 is inserted by being inserted into the cylindrical portion. The connection terminal portion 7 is composed of the terminal insertion portion 7c made of conductive rubber. Then, the connecting terminal portion 7 penetrates the insulating resin layer 6 and projects from the opening of the insulating case.

According to the present invention, the connection terminal 8 projecting from the rear surface side of the circuit board is inserted into the terminal insertion portion 7c made of conductive rubber of the connection terminal portion 7, and this terminal insertion portion 7c is also inserted.
A connecting member extending from the flyback transformer is also inserted into the. As a result, according to the present invention, the soldering work for mounting the connection terminal portion 7 on the back surface side of the circuit board is unnecessary, and the soldering work for mounting the high voltage variable resistor on the flyback transformer is unnecessary. Can be reduced. Further, the terminal insertion portion 7c made of conductive rubber has a cylindrical portion 7b.
Since it is housed in the cylindrical board 7b, even if the cylindrical portion 7b is firmly connected to the insulating resin layer formed on the back surface side of the circuit board, the terminal insertion portion made of conductive rubber inside the cylindrical portion 7b. The contraction force of the resin is not directly applied to 7c. Also, it receives force from the flow of mold resin that is filled when attaching the high-voltage variable resistor to the flyback transformer,
Even if the resin contracts when the molding resin is cured, the terminal insertion portion 7c made of conductive rubber does not move.
Moreover, since the terminal insertion portion 7c made of conductive rubber serves as a cushioning material, an unreasonable force is not applied to the connection portion. Therefore, according to the present invention, it is possible to prevent the occurrence of the disconnection state in the connection portion.

Further, in a state of being attached to the flyback transformer via a molding resin, each portion exposed in the opening of the high voltage variable resistor (the terminal insertion portion 7c made of conductive rubber is housed in the cylindrical portion 7b). An interface is formed between the surface of the connection terminal portion 7) and the layer of the cured molding resin. Since this interface has low insulation strength, if there is a crack in the insulation case or there is a slight gap in the fitting part between the insulation case of the high voltage variable resistor and the case of the flyback transformer, this interface may be There is a risk that discharge will occur. Therefore, the distance (creeping distance) of the interface formed between the conductive part of the terminal and the side wall of the insulating case
Is preferably as long as possible. As a configuration for extending this creepage distance, it is considered that the height of the side wall of the insulating case is increased (the depth of the opening is increased) and the length of the tubular portion 7b of the terminal is increased. However, if the side wall of the insulating case is made higher in height (the depth of the opening is deeper), the thickness of the insulating case becomes thicker, and as a result, the height dimension of the insulating case (the axial dimension of the operating shaft) Grows larger. As a result, the projecting dimension (dimension in the axial direction of the operating shaft) of the high voltage variable resistor projecting from the flyback transformer becomes large, and the outer shape of the flyback transformer to which the high voltage variable resistor is attached becomes large. The larger the protruding size of the high-voltage variable resistor, the more the weight balance of the flyback transformer is disturbed, and the flyback transformer is more likely to tilt. The larger outer shape of the flyback transformer not only violates the demand for downsizing, but also the weight balance of the flyback transformer is disturbed and the flyback transformer is easily tilted. It becomes exaggerated and causes the overall size of the flyback transformer to become larger. Therefore, when the terminal portion 7 is projected from the opening of the insulating case and a part of the terminal portion is inserted into the flyback transformer side as in the present invention, the thickness of the insulating case is increased (side wall of the insulating case). It is no longer necessary to increase the height dimension or the dimension of the operating axis in the axial direction), and the projecting dimension of the high voltage variable resistor projecting from the flyback transformer can be reduced. It is possible to reduce the outer shape of the attached flyback transformer and prevent the weight balance thereof from being greatly disturbed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a partial cross-sectional view showing an embodiment in which the present invention is applied to a high voltage variable resistor having a focus output and a screen output used in a part of a flyback transformer of a television. FIG. 2 also shows a side view of the resistor of FIG. In these figures, 1 is an insulating case formed of an insulating resin material and having an opening at one end,
The front wall portion 1a of the insulating case 1 is provided with tubular projections 1b1 and 1b2 projecting from the operation shafts 2a and 2b for operating the sliders of the two variable resistors, respectively. Since the structure of the variable resistor of this embodiment is well known, its illustration and description are omitted. A lead wire holding cylinder 3 that holds the lead wire integrally with the insulating case 1 is projectingly provided on one side wall portion 1c in the longitudinal direction of the insulating case 1. In addition, a lead wire for pulling out the focus output to the outside is inserted into the lead wire holding cylinder 3. A flange portion 1e is provided around the opening 1d of the insulating case 1.

Inside the insulating case 1, a partition wall 1f holds a component storage chamber 1g in which a slider (not shown) is stored, and a holding piece storage chamber 1 in which a lead wire holding means 4 described later is stored.
It is divided into h and. The partition wall 1f is provided to prevent outside air that enters the holding piece storage chamber 1h from entering the component storage chamber 1g and to enhance the insulating property.

As shown in FIG. 2, a side wall portion 1i of the case 1 is provided with a second lead wire holding cylinder 3 ', which is similar to the lead wire holding cylinder 3, and holds the second lead wire. A lead wire for drawing the screen output to the outside is inserted in the cylinder 3 ', and a holding piece storage chamber 1h is also provided in the case 1 corresponding to the lead wire holding cylinder 3'. Although not shown, the lead wire holding means 4 is also stored in the holding piece storage chamber 1h provided corresponding to the lead wire holding cylinder 3 '.

The lead wire holding cylinder 3 is provided in order to improve the insulation property especially when a high voltage is output to the outside as in this embodiment, and is especially provided when the output voltage is low. There is no need. A lead wire insertion hole consisting of a through hole is formed inside the lead wire holding cylinder 3 and on the side wall portion of the insulating case 1, and the lead wire insertion hole is inserted into the insulation coating portion of the coating cord that constitutes the lead wire to be inserted. So as to allow the large diameter portion 3a having a diameter substantially equal to the outer diameter of the coated cord and having one end open to the end face side of the lead wire holding cylinder 3.
A taper portion 3b having a taper extending continuously from the other end of the large diameter portion 3a and having a diameter that gradually decreases in the lead wire insertion direction (the direction of the arrow in the figure), and the taper portion 3b. The extended end is composed of a small diameter portion 3c that opens into the holding piece storage chamber 1h in the case 1. The diameter dimension of the small diameter portion 3c is set to be slightly larger than the outer diameter dimension of the end portion of the core wire of the lead wire (not shown) to be inserted.

If the large-diameter portion 3a that is long to some extent is provided in this way, the lead wire becomes substantially straight while the lead wire is inserted, so that the end portion of the core wire of the lead wire has a shape extending in the insertion direction of the lead wire. Be shaped. Further, the taper portion 3b forming a part of the lead wire insertion hole effectively acts to guide the end portion of the core wire of the lead wire to the center position. Even if the lead wire holding cylinder 3 is not provided, if the tapered portion 3b is provided,
The end of the core wire of the lead wire can be smoothly inserted into the case.

Reference numeral 5 denotes an insulating circuit board having a resistor circuit pattern including a focusing resistor and a screen resistor on a surface (not shown). Circuit board 5 is an insulating case 1
Is arranged so as to abut on the step portion 1j provided on the inner peripheral wall of the partition wall and one end face 1f1 of the partition wall 1f. Circuit board 5
The fixing is generally performed by using a thermosetting adhesive. In particular, the adhesive is used to attach the circuit board 5 to the electronic component handling a high voltage as in this embodiment in the component storage chamber 1g.
This is to improve the insulating property of and prevent moisture from entering the inside of the component storage chamber 1g.

A space formed by the back surface 5a of the circuit board 5 and the inner peripheral wall of the case 1 is filled with a thermosetting resin to form an insulating resin layer 6. Insulating resin layer 6
Are mainly provided for the purpose of strengthening the insulating property.

A member indicated by reference numeral 7 protruding from the opening side of the insulating case 1 is a connecting terminal portion connected to an electrode (not shown) provided on the back surface 5a side of the substrate 5. The connecting terminal portion 7 has a cylindrical portion 7b having a notch portion 7a extending in the axial direction and having a C-shaped cross section, and a terminal insertion portion 7c made of a cylindrical conductive rubber fitted in the cylindrical portion 7b. Composed of and. The connection terminal 8 protruding from the back surface 5a side of the substrate 5 is inserted into the terminal insertion portion 7c. When connecting a connecting wire (connecting means) such as a lead wire extending from the flyback transformer side to the connecting terminal portion 7, the core wire of the lead wire is connected from the axial end face side of the tubular portion 7b or the cutout portion 7a side. It suffices to insert the end portion into the terminal insertion portion 7c. By using the connection terminal portion 7 having such a configuration, lead wires can be easily connected. In order to facilitate the insertion of the core wire of the lead wire, it is preferable to make the tip of the core wire of the lead wire sharp.

A rod-shaped member protruding toward the other end face 1k in the longitudinal direction of the case 1 is a grounding connection terminal 9 made of a conductive metal material. Further, 10 is a lead wire holding cylinder 3
The lead wire holding piece is provided on the outer peripheral portion of the case 1 near the side wall portion 1c. The lead wire holding piece 10 holds the lead wire led out from the lead wire holding tube 3'for drawing the screen output to the outside. The lead wire holding piece 10 is provided with a fitting groove 10a into which the lead wire is fitted.

The specific construction of the lead wire sandwiching means housed in the sandwiching piece storage chamber 1h is as shown in FIGS. 3 to 6. The pair of sandwiching pieces used in this embodiment are integrally formed by punching and pressing a conductive metal plate having a rigid material such as phosphor bronze as a main material.

FIG. 3 shows a front view of the lead wire holding means 4 having a pair of holding pieces integrally formed, FIG. 4 is a sectional view taken along line IV-IV of FIG. 3, and FIG. 5 is a plan view. ing. The lead wire holding means 4 has an insertion portion 4a to be inserted into a mounting through hole 5b (FIG. 1) provided in the circuit board 5. As shown in FIG. 3, the insertion portion 4a has a convex shape, and the base portion 4a1 has a mounting through hole 5 formed in the substrate 5.
The bent portion 4a2 is bent to the back surface 5a side of the circuit board 5 in a state of being inserted in the b so as to prevent the lead wire holding means 4 from coming off (see FIG. 1).

The portion indicated by reference numeral 4b in FIG.
a is a flat portion having a surface 4b1 extending continuously with a and contacting the surface of the substrate 5, and as shown in FIG. 1, a non-contact surface 4b2 of the flat portion 4b and an electric circuit (not shown) provided on the surface of the circuit board 5. The soldering portion 11 is formed between the and. The flat portion 4b is continuously provided with an upright portion 4c extending in a direction substantially perpendicular to the surface of the circuit board 5. Standing part 4c
Is the first portion 4c1 located on the front surface side of the substrate 5 and the first portion 4c1.
And a second portion 4c2 composed of a pair of rectangular plate members standing up from both sides of the portion 4c1.

One end of a first holding piece 41 formed by cutting and raising a metal plate is fixed to the central portion of the first portion 4c1 of the standing portion 4c. In addition, the second portion 4 of the upright portion 4c
At the end portion of c2 opposite to the first portion 4c1, a support portion 4 for supporting a second holding piece 42 described later as shown in FIG.
d is provided so as to extend in a direction substantially perpendicular to the standing portion 4c. The first holding piece 41 and the second holding piece 42 hold the lead wire by holding the end portion of the core wire of the lead wire.

As shown in FIG. 4, the first holding piece 41 is
It is configured to be pushed by the end portion 12 of the core wire of the lead wire shown by the alternate long and short dash line and to be inclined in the insertion direction (the direction of the arrow in FIG. 4). Note that FIG. 4 shows the end portion 12 of the core wire of the lead wire.
Is a sectional view showing a state in which the lead wire is inserted all the way to the inside, and the state of the first holding piece 41 before the lead wire is inserted into the inside is as shown by a two-dot chain line in the figure. The first sandwiching piece 41 includes the upright portion 4
flat plate portion 41a having one end fixed to the first portion 4c1 of c
And a contact portion 41b extending from the other end of the flat plate portion 41a in a bending direction of the lead wire. Also the first
When the lead wire is inserted in the insertion direction, the other end of the sandwiching piece 41, that is, the tip portion of the contact portion 41b contacts a part of the outer periphery of the end 12 of the core wire of the lead wire, and the lead wire is inserted in the insertion direction. An edge portion 41c is provided which bites into a part of the outer circumference of the lead wire when pulled in the opposite direction. As shown in the plan view of the first holding piece 41 shown in FIG. 6 and the front view of FIG. 3, the contact portion 41b of the first holding piece 41 uses, for example, a jig having a corner portion in the insertion direction. The edge portion 41c is formed by pressing to form two inclined surfaces 41c1 extending outward.

The second holding piece 42 has a substantially semi-cylindrical shape, and the end portion on the side where the lead wire is inserted has a taper for smoothly receiving the end portion 12 of the core wire of the lead wire. The part 42a is formed. The second clamping piece 42 is
The end 12 of the core wire of the lead wire in cooperation with the first holding piece 41.
Is sandwiched between the lead wire and the end portion 12 of the core wire of the lead wire, and good electrical connection can be achieved. In particular, in this embodiment, since the second holding piece 42 is formed in a substantially semi-cylindrical shape, the inner peripheral surface 42b fits as much as possible with the outer peripheral surface of the core wire of the lead wire to increase the contact area. , Good electrical contact can be obtained.

In order to smoothly insert the end 12 of the core wire of the lead wire, the inner peripheral surface 42b of the second holding piece 42 is provided with a lead wire insertion hole provided in the wall portion of the case 1. It is preferable to position it on the extension line of the inner peripheral surface of the small-diameter portion 3c (FIG. 1) forming a part, or to arrange it so as to be positioned above the extension line. This is the second clamping piece 42
When the second holding piece 42 is arranged such that the inner peripheral surface 42b of the lead wire is positioned considerably below the extension line of the inner peripheral surface of the small diameter portion 3c of the lead wire insertion hole, the end 12 of the lead wire core wire 12 is This is because the end edge 12a comes into contact with the end surface of the second sandwiching piece 42 above the tapered portion 42a, so that the lead wire may not be inserted smoothly.

The length L in the insertion direction of the lead wire of the second holding piece 42 may be such that the lead wire can be held between it and the first holding piece 41. In order to securely clamp the end 12 of the core wire of the lead wire, the first clamping piece 41
At the maximum inclined position (the position shown in FIG. 4) up to the position beyond the tip of the first holding piece 41, the second holding piece 4
It is preferred to dimension L such that 2 is present.

In this embodiment, fixing means for fixing the second sandwiching piece to the substrate 5 is constituted by the insertion portion 4a, the flat portion 4b, the rising portion 4c and the like.

The mounting of the lead wire will be described below with reference to FIGS. 4 and 7. First, at the initial stage of inserting the end portion 12 of the core wire of the lead wire, first, the edge 12a of the end portion 12 of the core wire.
Contacts the two inclined surfaces 41c1. While the end edge 12a of the end portion 12 of the core wire is in contact with the inclined surface 41c1, the first
The holding piece 41 is pushed by the end portion 12 of the core wire of the lead wire, and is tilted in the insertion direction while increasing the tilt angle around the fixed one end. When the end 12 of the core wire of the lead wire is further inserted in the insertion direction, as shown in FIG.
A part of the outer circumference of 2 comes into contact with the edge 41c2 formed at the boundary between the inclined surface 41c1 and the end surface 41b1 of the contact portion 41b. In such a state, the increase of the inclination angle of the first holding piece 41 stops. In this state, the end portion 12 of the core wire is strongly pressed against the inner peripheral surface 42b of the second holding piece 42 by the spring force of returning to the original direction of the first holding piece 41.

After the insertion of the lead wire is stopped, if a force in the opposite direction to the lead wire, that is, a pull-out force is applied to the lead wire for some reason, a spring force is applied to the first holding piece 41 to return it to the original position. In addition, since the first holding piece 41 has a strength that does not deform unless a force of a predetermined force (for example, about 5 kg) or more is applied, the edge provided on the tip end portion of the first holding piece 41. The edge 41c2 of the portion 41c bites into a part of the outer circumference of the end portion 12 of the core wire of the lead wire to prevent the lead wire from coming off.

In the above embodiment, the end portion 1 of the core wire of the lead wire is
The inclination angle of the first holding piece 41 before inserting 2 is about 1
It is set to about 0 °. The inclination angle of the first holding piece 41 is such that, when the lead wire is inserted, the end portion of the core wire of the lead wire smoothly enters between the first holding piece 41 and the second holding piece 42 and the end of the core wire. Any angle may be used as long as it can be inclined in the insertion direction while being in contact with the outer circumference of the portion 12.

In the above embodiment, the lead wire holding means 4 does not come into contact with the case 1 at all.
Even when a high voltage is output, it is possible to prevent the inconvenience that the current leaks through the case 1. Further, since the holding means 4 is integrally formed of a conductive metal plate, there is an advantage that the holding means 4 is easy to attach and has a high mechanical strength. Further, since the lead wire holding cylinder 3 and the partition wall 1f are provided, sufficient insulation can be obtained even when outputting a high voltage.

Since the screen output electrode and the ground electrode are arranged close to each other in terms of the circuit structure, the connection terminal 9 crosses the lead wire insertion hole or the lead wire holding cylinder 3'for inserting the lead wire for screen output. It is also possible to provide it on the side wall portion 1k of the insulating case 1 which extends as a whole, but in this case, the lead wire holding cylinder 3'must be made considerably long.
Therefore, in this embodiment, the lead wire holding cylinder 3'is attached to the insulating case 1.
The insulating distance between the electrode for screen output and the connection terminal 9 is extended by providing it on the side wall portion 1i.

In the above embodiment, the pair of sandwiching pieces are integrally formed, but the first sandwiching piece 41 may be formed separately from the second sandwiching piece 42 and may be individually fixed. . When the first sandwiching piece 41 is formed separately, the first
Needless to say, the holding piece 41 may be formed of an insulating material. When the first holding piece 41 is separately formed and fixed, the fixed side end of the holding piece may be fixed to the inner surface of the case 1 when the output voltage is low.

In the above embodiment, the lead wire holding means 4 is constructed such that the second holding piece 42 is located on the case 1 side and the first holding piece 41 is located on the substrate 5 side. ,
The positional relationship between the second holding piece 42 and the first holding piece 41 may be reversed, and the second holding piece 42 and the first holding piece 4 may be reversed.
It goes without saying that 1 and 1 may be arranged so as to face each other in the lateral direction.

In the above embodiment, the shape of the first holding piece 41 is substantially rectangular, the shape of the edge 41c2 of the edge portion 41c is an isosceles isosceles triangular shape, and the contact surface 41c1 has two surfaces. However, the shape of the edge portion 41c provided at the tip end portion (other end) of the first holding piece 41 is such that the outer periphery of the end portion of the core wire of the lead wire is smoothly contacted and the lead wire is pulled in the direction opposite to the insertion direction. Any shape may be used as long as it bites into the outer circumference of the core wire of the lead wire.
For example, the shape of the edge 41c2 may be a substantially semicircular shape like the shape of the inner peripheral surface of the second holding piece 42, or may be a multi-sided shape.

The shape of the second holding piece 42 may be any shape as long as a sufficient contact area can be obtained. For example, it goes without saying that the cross-sectional shape may be V-shaped or more polyhedral. Furthermore, as shown in FIG. 8, if the rear end of the second holding piece 42 in the insertion direction is inclined toward the substrate 5, the end of the core wire of the lead wire can be held more strongly.

As shown in FIG. 1, since the above embodiment outputs a high voltage, the lead wire holding means 4 is fixed at a position away from the inner wall of the case, but a relatively low voltage is applied. When outputting, the lead wire holding means 4 can be arranged close to the inner wall of the case 1. By doing this, even if a strong pulling force acts on the lead wire,
The clamping means can be brought into contact with the inner wall surface of the case 1,
It is possible to prevent the holding means from tilting.

In the above embodiment, only one of the sandwiching pieces is configured to be tiltable, and the edge portion is provided on the tilting sandwiching piece. However, as shown in FIG. 9, the first and second sandwiching pieces are sandwiched. Both pieces 41 and 42 are inserted into the end 12 of the lead wire to be inserted.
It may be configured so as to be pushed and inclined by, and an edge portion may be provided at the tip end portion of each sandwiching piece. In this manner, if all the holding pieces can be tilted and the edge portion is provided at the tip of each holding piece, the lead wire can be more firmly prevented from coming off.

In the above embodiment, two sandwiching pieces are used, but the number of sandwiching pieces is not limited to two, and three or more sandwiching pieces 41 ', as shown in FIG.
Of course, 42 'and 43' may be arranged at equal intervals around the core of the lead wire so as to sandwich the ends of the core of the lead wire.

It should be noted that which of the plurality of holding pieces is to be electrically connected to the electrode of the circuit board 5 is arbitrary. Of course, all or part of the sandwiching piece may be fixed to the case according to the magnitude of the voltage or current output from the lead wire.

[0040]

According to the present invention, the connection terminal projecting from the back side of the circuit board is inserted into the terminal insertion portion made of conductive rubber of the connection terminal portion, and the flyback is also inserted into this terminal insertion portion. A connecting member extending from the transformer is also inserted. As a result, according to the present invention, the soldering work when attaching the connection terminal portion to the back surface side of the circuit board becomes unnecessary, and
It is possible to reduce the soldering work when mounting the high voltage variable resistor on the flyback transformer. Also, since the terminal insertion part made of conductive rubber is housed in the tubular part, even if the tubular part is firmly connected to the insulating resin layer formed on the back side of the circuit board, The contraction force of the resin is not directly applied to the terminal insertion portion made of conductive rubber inside. Also, even if the force is received from the flow of the mold resin that is filled when mounting the high-voltage variable resistor in the flyback transformer, or if the resin contracts when the mold resin cures, the terminal insertion part made of conductive rubber Will never move. Moreover, since the terminal insertion portion made of the conductive rubber serves as a cushioning material, an unreasonable force is not applied to the connection portion. Therefore, according to the present invention, it is possible to prevent the occurrence of the disconnection state in the connection portion.

Further, according to the present invention, when the connecting terminal portion is projected from the opening of the insulating case and a part of the terminal portion is inserted into the flyback transformer side, it is necessary to increase the thickness of the insulating case. It is possible to reduce the protrusion size of the high voltage variable resistor protruding from the flyback transformer. Further, the outer shape of the flyback transformer to which the high-voltage variable resistor is attached can be reduced, and the weight balance of the flyback transformer can be prevented from being greatly disturbed.

[Brief description of drawings]

FIG. 1 is a partial sectional view of an embodiment of a high-voltage variable resistor according to the present invention.

FIG. 2 is a side view of the variable resistor of FIG.

FIG. 3 is a front view of a lead wire holding means used in the embodiment of FIG.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

5 is a plan view of the lead wire holding means of FIG. 3. FIG.

FIG. 6 is a plan view of a first sandwiching piece.

FIG. 7 is an explanatory diagram showing a relationship between an end portion of a core wire of a lead wire and an edge portion of a first sandwiching piece.

FIG. 8 is a cross-sectional view showing a modified example of the second sandwiching piece.

FIG. 9 is a cross-sectional view showing another embodiment of the lead wire holding means used in the present invention.

FIG. 10 is an explanatory view showing still another embodiment of the lead wire holding means used in the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulation case 3,3 'Lead wire holding cylinder 3a Large diameter part 3b Tapered part 3c Small diameter part 4 Lead wire clamping means 5 Circuit board 12 Lead wire core end 41 First clamping piece 41c Edge 42 Second Clip

Claims (1)

[Claims] 1. A circuit board (5) having a resistor circuit pattern is housed in an opening of an insulating case (1) having an opening at one end, and a slider is provided between the insulating case and the surface of the circuit board. And an insulating resin layer (6) is formed by filling the opening of the insulating case with an insulating resin so as to cover the back surface of the circuit board, and the connection terminal (6) is formed so as to project from the back surface side of the circuit board. 8) is provided, and a connecting terminal portion for electrically connecting a connecting member extending from a flyback transformer to the connecting terminal (8) is fixed to the back surface side of the circuit board. The connecting terminal portion (7) surrounds the connecting terminal (8) and extends beyond the insulating resin layer (6) to form the insulating case (1).
(7b) provided so as to project from the opening of the
And a terminal insertion part (7c) made of a conductive rubber that is fitted into the tubular part and into which the connection terminal (8) is inserted, and the connection terminal part (7) includes the insulating resin layer (6). ), And protrudes from the opening of the insulating case.