JPH0927408A - High voltage variable resistor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high voltage variable resistor which makes it possible to connect a lead wire in the final stage of assembling and to retain the core wire of the lead wire filmly by a lead wire pinching means. SOLUTION: A lead wire pinching means 4, which is electrically connected to the resistor circuit pattern on a circuit board, is arranged between an insulating case 1 and a circuit board 5. The lead wire pinching means 4 has a plurality of clamp pieces which clamp the end part of the core wire of the lead wire, inserted from the lead wire inserting hole provided on the insulating case 1. The lead wire insulating hole is composed of a large diameter part 3a, which permits the insertion of the insulating-coated part of the lead wire with one end opened toward outside, a tapered part 3b which is extending continuously with the other end of the large diameter part 3a with the diameter becoming smaller in the direction of insertion of the lead wire, and a small diameter part 3c which opens into the insulating case 1 in continuity with the tapered part 3b and extends toward the lead wire pinching means 4.

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.

[0002]

2. Description of the Related Art A high-voltage variable resistor combined with a flyback transformer of a television is provided with a resistor circuit pattern including a focusing resistor and a screen resistor on the surface thereof, and a circuit board of an insulating case having an opening at one end. It has a structure in which it is housed inside, the opening of the insulating case is filled with an insulating resin, and an insulating resin layer is formed on the back surface side of the circuit board.

A lead wire is generally used for extracting the focus output and screen output from the high-voltage variable resistor.

[0004]

However, in the conventional high voltage variable resistor, after connecting the lead wire to the circuit board in advance, the opening of the insulating case is filled with the insulating resin and hardened. Therefore, the lead wire also hinders the filling of the resin and the insertion of the assembly into a constant temperature bath for curing the filled resin, which has been an obstacle to mass production. In addition, even when combined with a flyback transformer, the lead wire becomes an obstacle, and when the mold resin of the flyback transformer is cured in the thermostat, the presence of the lead wire causes a problem that the space in the thermostat cannot be used effectively. In addition, since the lead wires are connected in advance by soldering, it is necessary to individually create high-voltage variable resistors with different lead wire lengths depending on the model type, which is a problem with poor versatility. there were.

An object of the present invention is to provide a high voltage variable resistor which can connect lead wires at the end of assembly and can securely hold the core wire of the lead wire in the lead wire holding means.

[0006]

In the high-voltage variable resistor of the present invention, as shown in the embodiments shown in FIGS. 1 to 7, a circuit board 5 having a resistor circuit pattern is provided inside an insulating case 1. A lead wire insertion hole (3a to 3d) in which a slider is housed, a slider is housed between the insulating case 1 and the surface of the circuit board 5, and a lead wire whose core is insulated and coated is inserted into the insulating case 1.
3c) is formed, the lead wire holding means 4 electrically connected to the resistor circuit pattern on the circuit board is disposed between the insulating case 1 and the circuit board 5, and is inserted from the lead wire insertion hole. In addition, the core wire of the lead wire is a variable resistor for high voltage in which the lead wire holding means 4 holds the core wire.

In the present invention, the large-diameter portion 3a which allows the insertion of the insulating coating portion of the lead wire and has one end opening to the outside.
And a tapered portion 3b that extends continuously from the other end of the large diameter portion 3a and has a diameter that decreases in the lead wire insertion direction, and inside the insulating case 1 that is continuous with the tapered portion 3b. A lead wire insertion hole is formed by the small diameter portion 3c which is open to the bottom and extends toward the lead wire holding means 4.

In the large diameter portion 3a, the lead wire is shaped, and the core wire at the end of the lead wire is roughly shaped to extend in the insertion direction of the lead wire. Then, in the tapered portion 3b, the core wire of the lead wire is guided to the center position of the hole. Finally, as the core wire passes through the small diameter portion 3c, the core wire accurately extends toward the lead wire holding means 4. Therefore, according to the present invention, before the lead wire is inserted into the lead wire insertion hole, the lead wire core wire can be securely held by the lead wire holding means 4 without the work of shaping the lead wire core wire. You can

When the small diameter portion 3c is not provided at the tip of the taper portion 3b, the thickness of the wall portion around the tip of the taper portion 3b becomes very thin and becomes thin at the tip of the core wire of the lead wire. The wall portion may be broken, and the core wire of the lead wire cannot be accurately extended toward the lead wire holding means 4, which increases the possibility of connection failure.

[0010]

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

FIG. 1 is a partial 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, reference numeral 1 denotes an insulating case having an open end formed of an insulating resin material.
Tubular projections 1b1 and 1b2, through which operation shafts 2a and 2b for operating sliders of two variable resistors penetrate, respectively, are protruded from a front wall 1a of the insulating case 1. Since the configuration itself of the variable resistor according to the present embodiment is well known, illustration and description are omitted. A lead wire holding cylinder 3 for holding a lead wire integrally with the insulating case 1 is protruded from one of the side walls 1c in the longitudinal direction of the insulating case 1. Note that a lead wire for drawing a 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, the side wall portion 1i of the case 1 is provided with a second lead wire holding tube 3 ', which is similar to the lead wire holding tube 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 is an insulating circuit board having a resistor circuit pattern including a resistor for focus and a resistor for screen 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 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 connection terminal portion 7 has a notch portion 7a extending in the axial direction, a cylindrical portion 7b having a C-shaped cross section, and a terminal insertion portion 7c formed of a cylindrical conductive rubber fitted into the cylindrical portion 7b. It is composed of The connection terminal 8 protruding from the back surface 5a side of the substrate 5 is inserted into the terminal insertion portion 7c. This connection terminal 7
When connecting a connection wire such as a lead wire extending from the flyback transformer side to the terminal, the end of the core wire of the lead wire is connected to the terminal insertion portion 7c from the axial end surface side or the notch portion 7a side of the cylindrical portion 7b. Just put it in. Connection terminal portion 7 having such a configuration
By using, the lead wire 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.

The 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. 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 structure of the lead wire holding means housed in the holding piece housing chamber 1h is as shown in FIGS. 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 is 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
Are a first part 4c1 located on the front side of the substrate 5 and the first part 4c1.
And a second portion 4c2 comprising a pair of rectangular plate members rising 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 cooperates 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, a fixing means for fixing the second holding 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 pulling force is applied to the lead wire for some reason, a spring force for returning to the first clamping piece 41 acts. 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 angle of inclination of the first holding piece 41 is such that when a lead wire is inserted, the end 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 periphery of the portion 12.

In the above embodiment, since the lead wire holding means 4 does not contact the case 1 at all,
Even when a high voltage is output, it is possible to prevent such a disadvantage that a current leaks through the case 1. In addition, since the holding means 4 is integrally formed of a conductive metal plate, there is an advantage that mounting is easy and mechanical strength is strong. 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 the circuit configuration, the connecting 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.
Thus, in the present embodiment, the lead wire holding cylinder 3 ′ is connected to the insulating case 1.
The insulating distance between the screen output electrode and the connection terminal 9 is increased by providing the side wall portion 1i.

[Modification of Embodiment] In the above embodiment, the pair of sandwiching pieces are integrally formed, but the first sandwiching piece 41 is formed separately from the second sandwiching piece 42, and each of them is individually formed. It may be fixed. When the first sandwiching piece 41 is formed separately, it goes without saying that the first sandwiching 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.

Further, 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
1 may of course be arranged so as to oppose 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 triangle, 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. Further, 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 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. In this way, even if a strong pull-out force acts on the lead wire,
The holding means can be brought into contact with the inner wall surface of the case 1,
The holding means can be prevented from tilting.

[Other Embodiments] In the above embodiment, only one of the sandwiching pieces is configured to be tiltable, and the inclined sandwiching piece is provided with the edge portion. However, as shown in FIG. Both the first and second holding pieces 41 and 42 may be configured to be pushed and tilted by the end 12 of the lead wire to be inserted, and an edge portion may be provided at the tip of each holding 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 holding pieces are used, but the number of holding pieces is not limited to two, and as shown in FIG. 10, three or more holding pieces 41 ',
Of course, 42 'and 43' may be arranged at equal intervals around the core of the lead wire so as to sandwich the end of the core wire 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.

[0042]

According to the present invention, in the tapered portion of the lead wire insertion hole, the core wire of the lead wire is guided to the center position of the hole, and finally the core wire passes through the small diameter portion, so that the core wire is directed toward the lead wire holding means. The lead wire holding means can securely hold the lead wire's core wire without inserting the lead wire into the lead wire insertion hole before the lead wire is shaped. There is an advantage that can be.

[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. 1;

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 (2)

[Claims] 1. A circuit board having a resistor circuit pattern is housed inside an insulating case, a slider is housed between the insulating case and a surface of the circuit board, and a core wire is housed in the insulating case. A lead wire insertion hole into which a lead wire covered with insulation is inserted is formed, and a lead wire electrically connected to the resistor circuit pattern on the circuit board is provided between the insulating case and the circuit board. A high-voltage variable resistor in which clamping means is arranged, and the core wire of the lead wire inserted from the lead wire insertion hole is clamped by the lead wire clamping means, wherein the lead wire insertion hole is the lead wire. A large-diameter part that allows the insertion of the insulating coating part of and one end opens to the outside,
A tapered portion extending continuously with the other end of the large-diameter portion and having a diameter decreasing in the lead wire insertion direction; and an opening in the insulating case continuous with the tapered portion and A variable resistor for high voltage, comprising a small diameter portion extending toward the lead wire holding means. 2. The lead wire holding means has a plurality of holding pieces for holding an end portion of a core wire of the lead wire inserted from the lead wire insertion hole, and at least one of the plurality of holding pieces is provided. The high-voltage variable resistor according to claim 1, wherein each of the two holding pieces has an edge portion that bites into the core wire when a pulling force is applied to the core wire.