JP2004288865A - Electromagnetic induction unit having improved earth structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic induction unit in which cost reduction can be realized by omitting a work for bonding an earth wire to a bobbin. <P>SOLUTION: In the electromagnetic induction unit where windings 11, 12 and 13 and a T-type core 7 are fixed to a bobbin 1, an earth wire 20 is touching the core 7 and the forward end part of the earth wire 20 is forming a pin terminal part 20a being inserted into a wiring board K, the earth wire 20 has a bent level difference part 20h between the end of a part touching the core 7 and a pin terminal part 20p. An engaging ratchet 35 for blocking movement in the lateral direction and the direction perpendicular to the outer surface of the flange 3 of the bobbin 1 by engaging with the pin terminal part 20p, and a stop wall 37 for blocking retreat of the pin terminal part 20p in the direction of the core 7 by touching the level difference part 20h are formed on the outer surface of the flange 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electromagnetic inductor such as a transformer.
[0002]
[Prior art]
2. Description of the Related Art A bobbin in which a primary winding, a secondary winding, and a heater winding are wound apart from each other in an axial direction as an electromagnetic inductor for generating a high voltage of a conventional inverter-type high-frequency heating device (microwave oven). In some cases, a magnetic leg of a T-shaped core piece is inserted into the cylindrical portion of, and the arm portion of the T-shaped core piece is sandwiched and fixed from both sides in the axial direction. The core piece is grounded by a non-magnetic and conductive ground wire, and the tip of the ground wire is fitted and held in a ground wire holding portion formed on the upper surface of the bobbin. When this electromagnetic inductor is mounted on a wiring board, a ground wire is inserted into an insertion hole formed in the board and soldered together with the terminals of each winding. (For example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Application No. 2001-344798
[Problems to be solved by the invention]
However, when the electromagnetic induction device receives a pressing force generated by friction or the like when the pin terminal portion of the ground wire is inserted into the ground hole of the board, the electromagnetic wire has an effect of preventing the ground wire from retreating to the ground wire holding portion. As a result, the work of inserting the ground wire is hindered. In order to solve this problem, a part of the pin terminal portion of the ground wire has been bonded to the outer surface of the flange of the bobbin with an adhesive. For this reason, the man-hours for assembling the electromagnetic inductor have increased, and the cost has increased accordingly.
[0005]
The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide an electromagnetic inductor that can omit the above-mentioned bonding work and can realize a reduction in cost.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, in an electromagnetic inductor according to the present invention, a winding and a core are mounted on a bobbin, an earth wire is in contact with the core, and a tip of the earth wire is inserted into a wiring board. An electromagnetic inductor forming a pin terminal portion, wherein the ground wire has a bent step portion between an end of a contact portion with the core and a pin terminal portion; An engaging claw that engages with the pin terminal portion to prevent movement in a lateral direction and a direction orthogonal to the outer surface of the collar; and a core direction of the pin terminal portion that contacts the step portion on an outer surface of the collar. And a receiving wall for preventing retraction of the vehicle. According to the above configuration, since the step portion of the ground wire abuts on the receiving wall formed on the outer surface of the flange of the bobbin, it does not recede due to the pressing force when the pin terminal portion of the ground wire is inserted into the ground hole of the board. . Therefore, it is not necessary to adhere to the brim with an adhesive as in the related art, and the number of assembling steps is reduced, and the cost can be reduced.
[0007]
Preferably, a lateral run-out restricting wall is further formed to restrict lateral movement of the step. According to the above configuration, when the pin terminal portion of the ground wire is inserted into the ground hole of the substrate, the step portion tries to move in the horizontal direction when it receives a pressing force, but the movement is limited by contacting the lateral vibration regulating wall. Therefore, the lateral position of the pin terminal portion of the ground wire is restricted.
[0008]
Further, between the engaging claw and the receiving wall on the outer surface of the collar, a plurality of position regulating protrusions that contact the left and right side portions of the pin terminal portion to prevent the pin terminal portion from moving in the lateral direction. Is formed. According to the above configuration, since the lateral movement of the ground wire is regulated by the plurality of position regulating projections in addition to the engagement claws, the lateral movement of the tip end portion of the pin terminal portion is prevented.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of an electromagnetic inductor according to the present invention will be described with reference to the drawings.
1 is a front view of the electromagnetic inductor 100, FIG. 2 is a bottom view thereof, FIG. 3 is a side view thereof, FIG. 4 is a perspective view of the ground wire in FIG. FIG. 6A is a side view of the T-shaped core CR, and FIG. 6B is a plan view thereof. As shown in FIG. 5, the resin bobbin 1 has a cylindrical tube portion 2 and four flanges 3, 4, 5, and 6 formed integrally on the outer peripheral surface of the tube portion 2 in parallel with each other. . Further, the outer walls of the upper and lower ends of the flanges 3 and 6 respectively accommodate the arm portions 7a of the T-shaped core piece 7 shown in FIG. Core storage portions 3a and 6a surrounded by 26 are formed, and the leg portion 7b of the T-shaped core piece 7 is inserted into the cylindrical portion 2. A spacer 2s sandwiched between the legs 7b and 7b and a guide rib 2g that contacts the outer peripheral surface of the leg 7b are formed on the inner surface of the cylindrical portion 2. As shown in FIG. 1, four spacers 2s and four guide ribs 2g are provided at equal intervals in the circumferential direction.
[0010]
A primary winding 11 is wound cylindrically around a primary winding frame 8 formed between the collars 3 and 4, and a secondary winding 9 is wound around the secondary winding frame 9 formed between the collars 4 and 5. The winding 12 is wound in an aligned winding, and a one-turn heater winding 13 is wound around the heater winding frame 10 formed between the collars 5 and 6. As shown in FIG. 1, a lead wire 11 a at the beginning of winding of the primary winding 11 is drawn out from a draw-out portion 31 formed of a radially extending notch groove formed in the collar 3, and an outer surface of the collar 3 is formed. Is locked by a locking portion 32 integrally formed with the base member. The lead wire 11b at the end of the winding is also drawn out from the lead portion 33 and is locked by a locking portion 34 integrally formed on the outer surface of the collar 3. Preliminary solder is applied to the tips protruding from the locking portions 32, 34, and formed on the primary winding terminals 11at, 11bt.
[0011]
As shown in FIG. 2, the lead wire 12a at the start of winding of the secondary winding 12 and the lead wire 12b at the end of winding are formed by a lead portion 61 formed of a notch groove formed in the collar 6 and extending in the radial direction. The lead wire 12a is wound around the pin terminal 62a and soldered, and the lead wire 12b is wound around the pin terminal 62b and soldered. Further, the leading wire 13a at the beginning of winding of the heater winding 13 and the leading wire 13b at the end of winding are bent at an acute angle in a notched portion 51 formed in the collar 5 under tension so that the winding position is fixed. Are wound around and soldered to the pin terminals 63a and 63b, respectively. The pin terminals 62a, 62b, 63a, 63b are fixed to the bobbin 1 by insert molding.
[0012]
The ground wire 20 is, for example, a phosphor bronze wire, and as shown in FIG. 4, a V-shaped first core contact portion 20b is formed at the tip of the first holding portion 20a. A bent portion C1 at the base end of the first holding portion 20a is bent at an angle slightly smaller than 90 degrees to form an insertion portion 20c inserted into the cylindrical portion 2 of the bobbin 1, and a bent portion at the distal end of the insertion portion 20c. At C2, a second pressing portion 20d which is bent at an angle slightly smaller than 90 degrees and extends in the same direction as the first pressing portion 20a is formed, and V is located at a position of the second pressing portion 20d facing the first core contact portion 20b. A second core contact portion 20e in the shape of a letter is formed. A bent portion C3 at the tip of the second holding portion 20d forms a first lead-out portion 20f that is bent 90 degrees and extends in the horizontal direction along the arm portion 7a of the core 7, and further forms a core 7 of the first lead-out portion 20f. A bent portion C4 near the end of the arm portion 7a forms a second lead-out portion 20g that is bent 90 degrees and extends in the horizontal direction, and a bent portion C5 at the tip of the second lead-out portion 20g is turned downward by 90 degrees. A third lead-out portion 20h that is bent at a slightly smaller angle and extends in the axial direction of the bobbin 1 is formed. The bent portion C6 at the tip of the third lead-out portion 20h bends at the same angle as the bent portion C5 and the second holding portion 20d. A fourth lead-out portion 20i extending in the same direction is formed. The tip portion of the fourth lead-out portion 20i forms a pin terminal portion 20p inserted into a ground hole of the wiring board K (FIG. 3). By bending each of the bent portions C1 and C2 to an angle slightly smaller than 90 degrees, the contact pressure when the core CR is sandwiched between the first and second core contact portions 20b and 20e is increased, and the ground wire 20 is formed. This ensures the grounding effect of the core pieces 7 and 7.
[0013]
First, as shown in FIG. 1, the core pieces 7, 7 are attached to the bobbin 1 by inserting the insertion portion 20c of the ground wire 20 into the cylindrical portion 2 of the bobbin 1 and fitting into the guide rib groove 2g of FIG. Then, the T-shaped core piece 7 is rotated to a position where it does not hinder the insertion of the T-shaped core piece 7, and the core pieces 7, 7 are inserted into the cylindrical portion 2 of the bobbin 1, as shown in FIG. Next, the ground wire 20 of FIG. 1 is rotated to fit the first and second core contact portions 20b and 20e into the grooves 7c formed in the core pieces 7 and 7, and to position them. 20i is press-fitted into an engaging claw 35 formed at the upper end of the collar 3 and the base end of the fourth lead-out portion 20i is formed into a bar-shaped position regulating projection 36a, 36b formed on the upper surface of the collar 3. Insert between In this operation, the ground wire 20 is attached to the bobbin 1. As shown in FIG. 7, the engaging claw 35 has a fitting groove 2k having a C-shaped cross section opened upward, and the fourth lead-out portion 20i is fitted into the fitting groove 2k from above. The fourth lead portion 20i is prevented from moving upward in a lateral direction and perpendicular to the outer surface of the collar 3. The core pieces 7, 7 in which the leg portions 7b are inserted into the cylindrical portion 2, a method of bonding the tip surfaces of the leg portions 7b, 7b, if necessary, a core band is applied from outside the arm portions 7a, 7a. It is fixed to the bobbin 1 by a method or the like.
[0014]
As described above, the ground wire 20 attached to the bobbin 1 has the third lead-out portion 20h (step portion) on the upper surface of the collar 3 because the bent portion C5 is bent at an angle slightly smaller than 90 degrees. It comes into contact with the formed receiving wall 37. Therefore, even if a pressing force is applied when inserting the pin terminal portion 20p into the substrate K, the pin terminal portion 20p does not retreat. Further, since the lateral vibration restricting wall 38 is formed on the side of the receiving wall 37, the movement is restricted by the lateral vibration restricting wall 38 even if the pressing force becomes large and the stepped portion 20h attempts to escape in the horizontal direction. Is done. Therefore, insertion of the pin terminal portion 20p into the substrate K becomes easy.
[0015]
The electromagnetic inductor 100 configured as described above includes the terminals 11c and 11c of the primary winding 11, the pin terminals 62a and 62b of the secondary winding 12, the pin terminals 63a and 63b of the heater winding 13, and the pin terminal portion 20p. Are attached to the wiring board K in a state where they are inserted into the insertion holes of the wiring board K and are electrically connected, and the core pieces 7, 7 are grounded to the circuit via the ground wire 20.
[0016]
【The invention's effect】
According to the present invention, the portion constituting the pin terminal portion of the ground wire is engaged with the engagement claw formed at the end of the upper surface of the collar of the bobbin, so that the movement in the direction perpendicular to the outer surface of the collar is prevented. In addition to blocking, the stepped portion continuous to the portion constituting the pin terminal is made to abut against the receiving wall, so that when the pin terminal portion is inserted into the connection hole of the substrate, the pin terminal is not pressed even if a pressing force is applied. Since the part does not recede, fixing with an adhesive is not required, and the bonding step is omitted, thereby reducing the number of assembling steps and realizing cost reduction.
[Brief description of the drawings]
FIG. 1 is a front view of an electromagnetic inductor according to an embodiment of the present invention.
FIG. 2 is a bottom view of the embodiment.
FIG. 3 is a left side view of the embodiment.
FIG. 4 is a perspective view of the ground wire in FIG.
FIG. 5 is a sectional view taken along line VV of FIG. 1;
FIG. 6A is a side view of a T-shaped core CR, and FIG. 6B is a plan view thereof.
FIG. 7 is a perspective view showing a pin terminal portion of the ground wire and a holding mechanism in the vicinity thereof.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Bobbin, 2 ... cylinder part, 2g ... Guide rib, 2i ... Inner surface of a cylinder part, 2k ... Fitting groove, 2s ... Spacer, 3-6 ... Collar, 3a, 6a ... Core storage part, 7 ... T-shaped core piece , 7a: arm portion, 7b: leg portion, 7c: groove, 8: primary winding frame, 9: secondary winding frame, 10: heater winding frame, 11: primary winding, 11a, 11b, 12a, 12b, 13a, 13b: Lead wire, 11at, 11bt: Primary winding terminal, 12: Secondary winding, 13: Heater winding, 20: Ground wire, 20a: First holding part, 20b: First core contact part, 20c insertion part, 20d second holding part, 20e second core contact part, 20f first derivation part, 20g second derivation part, 20h third derivation part, 20i fourth derivation part, 20p ... Pin terminal part, 31, 33 ... Pull-out part, 32, 34 ... Locking part, 35 ... Engagement claw, 36a, 36b ... Position restricting projections, 37: receiving wall, 38: sideways restricting wall, 51: notch, 61: pull-out part, 62a, 62b: pin terminal, 63a, 63b: pin terminal, C1, C2, C3, C4, C5, C6 ... bent part.

Claims (3)

A winding and a core are mounted on a bobbin, the core is in contact with an earth wire, and an end of the earth wire forms a pin terminal portion to be inserted into a wiring board. The bent ground wire has a step portion between an end of a contact portion with the core and a pin terminal portion,
An engaging claw that engages with the pin terminal portion to prevent movement in a lateral direction and a direction orthogonal to the outer surface of the brim, on the outer surface of the bobbin collar, An electromagnetic inductor having a receiving wall for preventing retreat in a core direction. 2. The electromagnetic induction device according to claim 1, further comprising a lateral deflection restricting wall that restricts a lateral movement of the stepped portion. 3. The lateral movement of the pin terminal portion according to claim 1 or 2, further comprising contacting left and right side portions of the pin terminal portion between the engaging claw and a receiving wall on the outer surface of the collar. An electromagnetic inductor in which a plurality of position restricting protrusions for blocking are formed.

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