JP3027335B2 - High-voltage variable resistor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-voltage variable resistor. 2. Description of the Related Art A high-voltage variable resistor combined with a flyback transformer of a television has on its surface a resistor circuit pattern including a focus resistor and a screen resistor, and a circuit board having an open end at one end. It has a structure in which the insulating resin is housed inside the insulating case, the opening of the insulating case is filled with the insulating resin, and the insulating resin layer is formed on the back surface side of the circuit board. A lead wire is generally used for taking out a focus output and a screen output from a high-voltage variable resistor. [0004] However, in the conventional high-voltage variable resistor, after the lead wire is connected to the circuit board in advance, the opening of the insulating case is filled with an insulating resin and cured. Was. 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. Further, 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 constant temperature bath, the presence of the lead wire causes a problem that the space in the constant temperature bath cannot be effectively used. 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. It is an object of the present invention to provide a high-voltage variable resistor that can connect a lead wire at the end of assembly and that can securely hold a core wire of the lead wire by lead wire holding means. [0006] Means for Solving the Problems] high-voltage variable resistor of the present invention, the outer peripheral portion of the circuit board 5 is provided with a resistor circuit pattern as seen in the embodiment shown in FIGS. 1 to 7 One side open
Adhered to step 1j provided inside mouth-shaped insulating case 1
The slider is housed between the insulating case 1 and the front surface of the circuit board 5, and an insulating resin is attached to the back surface of the circuit board 5.
A resin layer 6 is formed, and a lead wire insertion hole (3a-3) into which a lead wire whose core wire is insulated and coated is inserted into the insulating case 1.
c) is formed, and between the insulating case 1 and the circuit board 5, the lead wire holding means 4 electrically connected to the resistor circuit pattern on the circuit board is arranged and inserted through the lead wire insertion hole. The core wire of the lead wire is a high-voltage variable resistor that is held by the lead wire holding means 4. In the high voltage variable resistor according to the present invention, the lead wire
The holding means 4 is a lead wire inserted from a lead wire insertion hole.
Having a plurality of holding pieces 41 and 42 for holding the end of the core wire of
And at least one holding piece 41 of the plurality of holding pieces is
When the pulling force is applied to the sandwiched core,
And the lead wire holding means 4 is an insulating case.
Arranged so as not to contact the inner wall surface adjacent to the step 1j
Have been. According to the present invention, the circuit board is formed on the back surface of the circuit board.
After forming an insulating resin layer,
After the combination, the lead wires can be connected.
In particular, in the present invention, the lead wire holding means 4 is
It is arranged so as not to contact the inner wall surface adjacent to the step 1j.
The circuit board is joined to the step 1j of the insulating case 1.
Adhesive is applied along the inner wall of the insulation case.
The adhesive that has flowed into the inside of the
Touch the holding pieces 41, 42 of the step 4 to fix the holding pieces 41, 42.
There is no risk of being in a fixed state. If the adhesive is the lead
When touching the holding pieces 41 and 42 of the wire holding means 4 and hardening,
The holding pieces 41 and 42 are fixed, and the holding pieces 41 and 42 are fixed.
Is weaker in pinching the core of the lead wire,
Although there is a problem that it does not bite, according to the present invention,
Such a defect does not occur. 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 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 1e is provided around the opening 1d of the insulating case 1. The interior of the insulating case 1 includes a component storage chamber 1g in which a slider (not shown) is stored by a partition wall 1f and a holding piece storage chamber 1 in which a lead wire holding means 4 described later is stored.
h. The partition wall 1f is provided to prevent outside air entering the holding piece storage chamber 1h from entering the component storage chamber 1g and to enhance insulation. As shown in FIG. 2, a second lead wire holding tube 3 'similar to the lead wire holding tube 3 is provided on the side wall portion 1i of the case 1, and this second lead wire holding tube 3' is provided. A lead wire for drawing a screen output to the outside is inserted into the tube 3 ', and a holding piece storage chamber 1h is also provided in the case 1 corresponding to the lead wire holding tube 3'. Although not shown, the lead wire holding means 4 is also housed in the holding piece storage chamber 1h provided corresponding to the lead wire holding cylinder 3 '. The lead wire holding cylinder 3 is provided to enhance insulation when a high voltage is output to the outside as in this embodiment, and is provided especially when the output voltage is low. No need. A lead wire insertion hole formed of a through hole is formed in the inside of the lead wire holding cylinder 3 and the side wall portion of the insulating case 1, and the lead wire insertion hole is used to insert an insulation coating portion of a coating cord constituting a lead wire to be inserted. Large diameter portion 3a having a diameter substantially equal to the outer diameter of the covering cord and having one end opened to the end face side of the lead wire holding cylinder 3
And a tapered portion 3b extending continuously to the other end of the large-diameter portion 3a and having a taper whose diameter gradually decreases in the lead wire insertion direction (the direction of the arrow shown in the drawing). An extended end is constituted by a small-diameter portion 3c opening to the holding piece storage chamber 1h in the case 1. The diameter of the small diameter portion 3c is set to be slightly larger than the outer diameter of the end of the core wire of the lead wire (not shown) to be inserted. When the large-diameter portion 3a having a certain length is provided, the lead wire becomes substantially straight while the lead wire is inserted, so that the end of the core wire of the lead wire has a shape extending in the lead wire insertion direction. Be shaped. Further, the tapered portion 3b constituting a part of the lead wire insertion hole effectively acts to guide the end of the core wire of the lead wire to the center position. Even when the lead wire holding cylinder 3 is not provided, if the tapered portion 3b is provided,
The end of the core of the lead wire can be smoothly inserted into the case. Reference numeral 5 denotes an insulating circuit board provided with a resistor circuit pattern including a focus resistor and a screen resistor on a surface (not shown). The circuit board 5 is the insulating case 1
Are arranged so as to abut on a stepped portion 1j provided on the inner peripheral wall and one end face 1f1 of the partition wall 1f. Circuit board 5
Is generally fixed using a thermosetting adhesive. Particularly, the use of an adhesive for mounting the circuit board 5 is a reason why the electronic component handling a high voltage as in the present embodiment is used for the electronic component handling room 1g.
This is for the purpose of improving the insulation of the device and preventing moisture from entering the interior of the component storage chamber 1g. As shown in FIG.
In addition, the lead wire holding means 4 is provided between the wall surface of the holding piece storage chamber 1h and the place.
They are arranged at a fixed distance. That is,
The holding means 4 does not contact the wall surface of the holding piece storage chamber 1h.
Are located. As a result, the contact flowing from the step portion 1j
The adhesive touches the holding pieces 41 and 42 of the lead wire holding means 4 and
There is no risk of solidification. 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
Is provided mainly for enhancing insulation. A member indicated by reference numeral 7 protruding from the opening side of the case 1 is a connection 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 of the lead wire, it is preferable to sharpen the tip of the core of the lead wire. A rod-shaped member projecting toward the other end face 1k in the longitudinal direction of the case 1 is a ground connection terminal 9 made of a conductive metal material. 10 is a lead wire holding cylinder 3
Lead wire holding pieces provided on the outer peripheral portion of the case 1 near the side wall portion 1c. The lead wire holding piece 10 holds a lead wire led out from the lead wire holding tube 3 'in order to draw 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 stored in the holding piece storage chamber 1h is as shown in FIGS. The pair of holding pieces used in this embodiment are formed integrally by punching and pressing a conductive metal plate mainly made of a rigid material, for example, phosphor bronze. FIG. 3 is a front view of the lead wire holding means 4 having a pair of integrally formed holding pieces, FIG. 4 is a sectional view taken along the 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 that is 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 provided in the substrate 5.
The bent portion 4a2 is bent toward the back surface 5a of the circuit board 5 in the state of being inserted into the circuit board 5 to prevent the lead wire holding means 4 from being removed (see FIG. 1). The portion indicated by reference numeral 4b in FIG.
1, a flat portion having a surface 4b1 extending continuously with the surface of the substrate 5 and having 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 as shown in FIG. Is formed between them. The flat portion 4b is provided with an upright portion 4c extending substantially perpendicular to the surface of the circuit board 5 continuously. 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. At the center of the first portion 4c1 of the upright portion 4c, one end of a first holding piece 41 formed by cutting and raising a metal plate is fixed. Also, the second portion 4 of the upright portion 4c
At the end opposite to the first portion 4c1 of c2, as shown in FIG.
d is provided so as to extend in a direction substantially perpendicular to the upright portion 4c. The first holding piece 41 and the second holding piece 42 hold the end of the core wire of the lead wire and hold the lead wire. As shown in FIG. 4, the first holding piece 41 is
It is configured to be pushed by the end 12 of the core of the lead wire indicated by the dashed line and to be inclined in the insertion direction (the direction of the arrow in FIG. 4). FIG. 4 shows the end 12 of the core of the lead wire.
Is a cross-sectional view of a state where the lead wire is inserted to the back, and a state of the first holding piece 41 before the lead wire is inserted to the back is as shown by a two-dot chain line in FIG. The first holding piece 41 includes the upright portion 4
c, a flat plate portion 41a having one end fixed to the first portion 4c1
And a contact portion 41b which is bent from the other end of the flat plate portion 41a in the insertion direction of the lead wire and extends. Also the first
When the lead wire is inserted in the insertion direction, the other end of the holding piece 41, that is, the tip end of the contact portion 41b, makes contact with a part of the outer periphery of the end 12 of the core wire of the lead wire, and the lead wire An edge portion 41c that cuts into a part of the outer periphery of the lead wire when pulled in the opposite direction is provided. 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 is inserted in a To form two inclined surfaces 41c1 extending outward to form an edge portion 41c. The second holding piece 42 has a substantially semi-cylindrical shape, and has a tapered end on the side where the lead wire is inserted for smoothly receiving the end 12 of the core wire of the lead wire. A portion 42a is formed. The second holding piece 42 is
The end 12 of the core wire of the lead wire cooperates with the first holding piece 41.
And the electrical connection with the end 12 of the core of the lead wire can be made well. In particular, in the present embodiment, the contact area is increased by forming the second holding piece 42 into a substantially semi-cylindrical shape so that the inner peripheral surface 42b contacts the outer peripheral surface of the core wire of the lead wire as much as possible. Good electrical contact can be obtained. In order to smoothly insert the end 12 of the core of the lead wire, the inner peripheral surface 42b of the second holding piece 42 is inserted into the lead wire insertion hole provided in the wall of the case 1. It is preferable to position the portion on the extension of the inner peripheral surface of the small diameter portion 3c (FIG. 1) constituting a part thereof, or to arrange the portion so as to be located above the extension. This is the second holding piece 42
When the second sandwiching piece 42 is arranged so that the inner peripheral surface 42b of the lead wire is positioned considerably below the extension of the inner peripheral surface of the small diameter portion 3c of the lead wire insertion hole, the end 12 of the core wire of the lead wire is This is because the edge 12a comes into contact with the end surface above the tapered portion 42a of the second holding piece 42, so that the lead wire may not be inserted smoothly. The length L of the second holding piece 42 in the direction in which the lead wire is inserted may be any size as long as the lead wire can be held between the second holding piece 42 and the first holding piece 41. In order to securely hold the end 12 of the core wire of the lead wire, the first holding piece 41 is required.
The second holding piece 4 is moved to a position before the tip of the first holding piece 41 at a position where the first holding piece 41 is inclined at the maximum (the position in FIG. 4).
Preferably, dimension L is determined such that 2 is present. In this embodiment, a fixing means for fixing the second holding piece to the substrate 5 from the insertion portion 4a, the flat portion 4b, the upright portion 4c and the like is constituted. The mounting of the lead wire will be described below with reference to FIGS. First, in the initial stage of insertion of the end 12 of the core of the lead wire, first, the edge 12a of the end 12 of the core is inserted.
Contacts the two inclined surfaces 41c1. While the edge 12a of the end 12 of the core wire is in contact with the inclined surface 41c1, the first
The holding piece 41 is pushed by the end 12 of the core wire of the lead wire, and tilts with its tilt angle increasing in the insertion direction about the fixed end. When the end 12 of the core of the lead wire is further inserted in the insertion direction, as shown in FIG.
A part of the outer periphery 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 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 the first holding piece 41 returning to the original direction. After the insertion of the lead wire is stopped, if a force in the direction opposite to the insertion direction, that is, a pulling force is applied to the lead wire for some reason, a spring force for returning to the first holding piece 41 acts. In addition, since the first holding piece 41 has such strength that the first holding piece 41 does not deform unless a predetermined force (for example, about 5 kg) or more is applied, the edge provided at the distal end of the first holding piece 41 The edge 41c2 of the portion 41c cuts into a part of the outer periphery of the end 12 of the core wire of the lead wire to prevent the lead wire from being pulled out. In the above embodiment, the end 1 of the core wire of the lead wire is used.
Before the insertion of the second holding piece 41, the inclination angle of the first holding piece 41 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, the configuration is adopted in which 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 a high voltage is output. Since the screen output electrode and the ground electrode are arranged close to each other in the circuit configuration, the connection terminal 9 passes over the lead wire insertion hole for inserting the lead wire for screen output or the lead wire holding cylinder 3 '. It can be provided on the side wall portion 1k of the insulating case 1 extending, but in this case, the lead wire holding tube 3 'must be considerably long.
Therefore, in this embodiment, the lead wire holding cylinder 3 'is connected to the insulating case
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 holding pieces are integrally formed. However, the first holding piece 41 is formed separately from the second holding piece 42, and each piece is individually formed. It may be fixed. When the first holding piece 41 is formed separately, the first holding piece 4
Of course, 1 may be formed of an insulating material. First
In the case where the holding pieces 41 are separately formed and fixed,
When the output voltage is low, the fixed end of the holding piece may be fixed to the inner surface of the case 1 as a matter of course. In the above embodiment, the lead wire holding means 4 is configured so 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-described 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 triangle, and the contact surface 41c1 has a shape having two surfaces. However, the shape of the edge portion 41c provided at the distal end portion (the 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 smoothly contacts and the lead wire is drawn in the direction opposite to the insertion direction. Any shape may be used as long as it penetrates the outer periphery 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 polyhedral 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 of a V-shape or a multi-faced shape. 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. 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 holding pieces is configured to be able to be inclined, and the edge portion is provided on the inclined holding piece. However, as shown in FIG. 1st and 2nd holding pieces 41 and 4
2 may be configured to be inclined by being pushed by the end 12 of the lead wire to be inserted, and an edge portion may be provided at the tip end of each holding piece. If all the holding pieces can be inclined in this way and the edge portion is provided at the tip of each holding piece, the lead wire can be more securely 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 three or more holding pieces 41 ', as shown in FIG.
Needless to say, 42 'and 43' may be arranged at equal intervals around the core wire of the lead wire so as to sandwich the end of the core wire of the lead wire. It is to be noted that which of the plurality of holding pieces is electrically connected to the electrode of the circuit board 5 is optional. Also, according to the magnitude of the voltage or current output from the lead wire, all or a part of the holding piece may be fixed to the case. According to the present invention, on the back surface of the circuit board,
After forming an insulating resin layer
After combining with the lead wire can be connected
You. In particular, in the present invention, the means for holding the lead wire
It is arranged so that it does not contact the inner wall surface adjacent to the step
The adhesive that joins the circuit board to the step of the insulating case
Flow into the insulation case along the inner wall of the insulation case.
The adhesive that has flowed in and has flowed into the holding piece of the lead wire holding means
There is no possibility that the holding piece will be fixed by touching the holding piece.

BRIEF DESCRIPTION OF THE 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 in FIG. 1; 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; FIG. 5 is a plan view of the lead wire holding means of FIG. 3; FIG. 6 is a plan view of a first holding piece. FIG. 7 is an explanatory diagram showing a relationship between an end of a core wire of a lead wire and an edge of a first holding piece. FIG. 8 is a sectional view showing a modification of the second holding piece. FIG. 9 is a 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. [Description of Signs] 1 Insulating cases 3, 3 'Lead wire holding cylinder 3a Large diameter portion 3b Tapered portion 3c Small diameter portion 4 Lead wire holding means 5 Circuit board 12 Lead wire core end 41 First holding piece 41c Edge Part 42 second holding piece

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Sho 59-125808 (JP, U) Japanese Utility Model Sho 55-146679 (JP, U) Japanese Utility Model Sho 60-59471 (JP, U) Japanese Utility Model Sho 57- 157075 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01C 1/14, 13/00

Claims (1)

(57) [Claims] The outer peripheral part of the circuit board provided with the resistor circuit pattern
Adhesive is applied to the step provided inside the open case
A slider was housed between the insulating case and the surface of the circuit board, an insulating resin layer was formed on the back surface of the circuit board, and a core wire was insulated and coated on the insulating case. A lead wire insertion hole into which a lead wire is inserted is formed, and a lead wire holding means electrically connected to the resistor circuit pattern on the circuit board is arranged between the insulating case and the circuit board. A high-voltage variable resistor in which 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 clamping means is inserted from the lead wire insertion hole.
A plurality of pinches for pinching the ends of the core wires of the lead wires
And at least one of the plurality of clamping pieces
When the pulling force is applied to the held core wire, the holding piece is
An edge portion that cuts into the core wire, and the lead wire holding means is provided on the step portion of the insulating case.
A high-voltage variable resistor, which is arranged so as not to contact an adjacent inner wall surface .