JPH0644127U - Ignition coil for internal combustion engine - Google Patents

Abstract

(57) [Summary] [Purpose] The assembly work such as the winding process can be simplified and the wire is not broken. [Structure] A high-voltage diode 20 is arranged in a high-voltage tower 19 of a case 13 provided with a high-voltage output terminal, and a connection conductor 21
Has a connection part connected to the input side electrode 23 of the high voltage diode and an engagement part connected to the secondary coil 15 side, and the bobbin of the secondary coil has a terminal terminal 30a connected to the secondary coil.
When the bobbin is put in a predetermined position in the case, the terminal terminal engages with the engaging portion of the connecting conductor, and the connecting portion of the connecting conductor connects with the input side electrode of the high voltage diode. The positions of the terminals and the positions of the connecting portion and the input side electrode are set respectively, and the insulating material 33 is injected into the case with the terminal terminal engaging the engaging portion and the connecting portion connected to the input side electrode. Fixed

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an ignition coil of an internal combustion engine, in which a high-voltage diode that blocks a secondary voltage generated at the start of energization of a primary current is fixed to the case side.

[0002]

[Prior art]

 The ignition coil generates a back electromotive force in the primary coil according to the amount of change in the primary current and boosts it with a magnetically coupled secondary coil.At normal ignition timing, a high voltage is generated when the primary current is cut off. However, a voltage is generated even when the current changes when the primary current starts to flow. The direction of the current is opposite to the high voltage generated at the normal timing, so the polarity of the voltage is also opposite. That is, since the voltage generated in the normal ignition coil has a negative polarity, the voltage generated at the start of energization has a positive polarity. Therefore, in order to supply only the negative voltage to the plug side, it is necessary to insert a high voltage diode that blocks the positive voltage in series with the secondary winding. The high-voltage diode 1 inserted in series with the secondary winding has a structure in which it is held by holding portions 3 and 3 formed on the bobbin 2 of the secondary coil, as shown in FIG.

[0003]

[Problems to be solved by the device]

 However, if the structure in which the high voltage diode 1 is held by the bobbin 2 of the secondary coil is adopted, the electric wire of the secondary coil cannot be wound with the high voltage diode 1 held by the bobbin 2. The end of the wire is electrically connected to one lead wire 1a of the high voltage diode 1, and the other lead wire 1b of the high voltage diode 1 is connected to the high voltage connection lead wire 4 to be connected to the high voltage output terminal of the case. There must be. Therefore, the manufacturing process is troublesome and requires a lot of time and labor. Further, since the secondary wire is wound around and electrically connected to the lead wire 1a of the high-voltage diode 1, the secondary wire is broken and the defect rate is high. Therefore, an object of the present invention is to provide an ignition coil with a built-in high-voltage diode, which has good workability in the manufacturing process and is highly reliable.

[0004]

[Means for Solving the Problems]

 The present invention has been developed in view of the above, and blocks the voltage generated in the secondary coil except for the primary coil, the secondary coil, the iron core magnetically coupling the primary coil and the secondary coil, and the ignition timing. An ignition coil for an internal combustion engine that has a high-voltage diode inside the case and boosts the voltage supplied from the low-voltage terminal connected to the primary coil and takes it out from the high-voltage output terminal via the high-voltage diode connected to the secondary coil, The present invention is characterized in that a high voltage diode is arranged in a high voltage tower of a case where a high voltage output terminal is provided, and an input side of the high voltage diode is electrically connected to a secondary coil through a connecting conductor. In addition, the input side electrode is integrally formed at one end of the high voltage diode and the output side electrode is integrally formed at the other end, and the high voltage diode is inserted and connected in the high voltage tower with the input side electrode protruding inside the case. The conductor is provided with a connecting part for connecting to the input side electrode and an engaging part for connecting to the secondary coil side, and the bobbin of the secondary coil is provided with a terminal terminal electrically connected to the secondary coil. The position of the engaging portion and the terminal terminal is such that the terminal terminal engages with the engaging portion of the connecting conductor and the connecting portion of the connecting conductor connects with the input side electrode of the high voltage diode when the , And the position of the connection part and the input side electrode are set respectively, and the insulating material is injected and fixed in the case with the terminal terminal engaging the engaging part and the connection part connected to the input side electrode. Is.

[0005]

[Action]

 When the secondary coil is inserted into the case to the specified position, the high voltage terminal provided on the bobbin of the secondary coil engages with the engaging part of the connecting conductor and the connecting part connects to the input side electrode of the high voltage diode. The secondary coil and the high-voltage output terminal of the high-voltage tower are electrically connected via the connection conductor with the high-voltage diode directly inserted. When the insulating material is injected into the case in this state, the secondary coil, the connecting conductor, etc. are fixed. When a voltage is supplied to the primary coil, the magnetically coupled secondary coil boosts the counter electromotive force of the primary coil. Since the high voltage generated when the primary current is cut off at the normal ignition timing is a negative voltage, it is supplied to the plug side through the high voltage diode, but the voltage generated in response to the current change at the start of the primary current conduction is positive. Since this is a positive voltage, this voltage is not blocked by the high voltage diode and supplied to the plug side.

[0006]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the ignition coil 11 includes a primary coil 14, a secondary coil 15, and an iron core that magnetically couples the primary coil 14 and the secondary coil 15 inside a plastic case 13 having an opening 12. 16 is provided, and the lead wire 14 ′ of the primary coil 14 is connected to the low-voltage terminal 18 in the cylindrical low-voltage cord fitting portion 17 provided at one end of the case 13 on the side opposite to the low-voltage cord fitting portion 17. A high-voltage diode 20 is arranged in a cylindrical high-voltage tower 19 projecting from the above, and the input side of the high-voltage diode 20 is electrically connected to the secondary coil 15 via a connecting conductor 21. The iron core 16 is a closed magnetic circuit iron core, and FIG. 1 shows a part of the primary coil that penetrates the bobbin.

As shown in FIG. 2, the high voltage diode 20 is housed in a pipe 22, and one opening of the pipe 22 is closed by an input side electrode 23 connected to an input side lead wire 20 a. The other opening is closed by the output electrode 24 connected to the output lead wire 20b. Then, by forming the step portion 25 on the outer peripheral surface of the pipe 22 to make the outer diameter on the input side small and the outer diameter on the output side large, the polarity of the high-voltage diode 20 can be easily identified, and the high-voltage tower can be easily identified. The step portion 25 functions as a stopper when it is inserted into the inside of 19. Therefore, when the high-pressure diode 20 is press-fitted from the opening at the tip of the high-pressure tower 19, the step 25 of the pipe 22 engages with the step formed on the inner peripheral surface of the high-pressure tower 19, whereby the high-voltage diode 20 is pushed. Stops at a predetermined position, and the projection 23a of the input-side electrode 23 projects into the coil storage chamber 26 of the case 13.

The output electrode 24 of the high voltage diode 20 is located deeper than the tip opening of the high voltage tower 19 and functions as a high voltage output terminal. Therefore, when one end of a high-voltage connection fitting connected to the plug side, for example, a spring, is inserted from the front end opening of the high-voltage tower 19, the high-voltage connection fitting contacts the output side electrode 24 and is electrically connected.

As shown in FIG. 3, the secondary coil 15 includes a secondary bobbin 29 having a plurality of fins 28 ... The secondary wire is wound, and secondary coil terminal terminals 30a, 30b, 30c, 30d are provided on the outer surfaces of the fins 28, 28 located at the ends. The two terminals 30a and 30b are conductive at their base ends, the end of the secondary wire is soldered to one terminal 30b, and the other terminal 30a is connected to the high voltage diode 20 via the connecting conductor 21. It is electrically connected to the input side electrode 23 of.

The connection conductor 21 conducts the voltage of the secondary coil 15 to the input side electrode 23 of the high voltage diode 20, and in the embodiment shown in FIG. 4, a metal plate having elasticity is punched out into a substantially L shape. In the end of the long piece 21a, a chrysanthemum washer-shaped hole is formed as a connecting portion 31, and at one side edge of the short piece 21b, a substantially V-shaped notch opened in the longitudinal direction of the long piece 21a is formed. It is formed as the engaging portion 32. Then, when the bobbin 29 is put in a predetermined position in the case 13, the engaging portion 32 and the connecting portion 31 cause the terminal terminal 30a to engage with the engaging portion 32 of the connecting conductor 21 and the connecting portion 31 of the connecting conductor 21. Is connected to the input side electrode 23 of the high voltage diode 20.

When the secondary coil 15 and the connecting conductor 21 are set inside the case 13, the terminal terminal 30 a of the secondary coil 15 is previously sandwiched in the engaging portion 32 of the connecting conductor 21 to set the engaging portion 32. The high-voltage diode protruding into the coil storage chamber 26 is pushed forward from the opening 12 into the coil storage chamber 26 of the case 13 until it reaches the predetermined position where the tip of the secondary bobbin 29 contacts the inner wall. When the connecting portion 31 is located at the tip of the protrusion 23 a of the input-side electrode 23 of 20 and the long piece 21 a of the connecting conductor 21 is pressed toward the high-voltage diode 20 side, the protrusion 23 a of the input-side electrode 23 becomes inside the connecting portion 31. After fitting, the secondary coil 15 and the high voltage diode 20 are electrically connected via the connection conductor 21.

Before inserting the secondary coil 15, the connecting conductor 21 is put in the coil housing chamber 26 in advance and the connecting portion 31 is connected to the input-side electrode 23 of the high voltage diode 20. Alternatively, the terminal terminal 30a may be engaged with the engaging portion 32 by pushing in 15. In this case, a positioning portion for a connecting conductor formed of a protrusion or a ridge is formed on the inner surface of the coil housing chamber 26, and the engaging portion 32 guides the positioning portion while the connecting portion 31 is connected to the input side electrode 23. Thus, if the terminal terminal 30a is configured to smoothly engage with the engaging portion 32 when the secondary coil 15 is pushed in at a predetermined position, the assembling work becomes easier.

When the coils 14, 15 and the connecting conductor 21 are assembled in the case 13 as described above, the terminal terminal 30a is engaged with the engaging portion 32 and the connecting portion 31 is connected to the input side electrode. An insulating material 33 such as a synthetic resin is injected into the case 13 in a state of being connected to the case 13, and each component is fixed in a state where the above-mentioned parts are electrically connected by the solidification of the insulating material 33.

When a low voltage is supplied from the low voltage terminal 18 of the ignition coil 11 thus assembled to the primary coil 14, the counter electromotive force of the primary coil 14 is boosted by the magnetically coupled secondary coil 15. Since the high voltage generated when the primary current is cut off at the normal ignition timing is a negative voltage, the boosted electromotive force passes through the high voltage diode 20 and is supplied to the plug side from the high voltage cord connected to the high voltage tower 19. Ignite. However, since the voltage generated with respect to the change in current at the start of energization of the primary current is a positive polarity voltage, this voltage is not blocked by the high voltage diode 20 and is not supplied to the plug side.

[0015]

[Effect of device]

 As described above, according to the present invention, since it is not necessary to hold the high voltage diode on the bobbin in the secondary coil winding, the secondary wire can be wound around the bobbin while holding the terminal terminal. The coil winding process can be simplified, and the terminal treatment of the secondary wire can now be done at the terminal terminal. Compared with the conventional terminal treatment with high voltage diode lead wires, the semi-fixed diode lead wire is used. It is possible to eliminate the troubles such as disconnection related to. Therefore, the efficiency of the assembling work can be remarkably improved, the generation rate of defective products can be reduced, and an inexpensive and highly reliable ignition coil can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view of an ignition coil according to the present invention.

FIG. 2 is a front view of a high voltage diode whose right half is a cross section.

FIG. 3 is a perspective view of a secondary coil.

FIG. 4 is a perspective view of a connection conductor.

FIG. 5 is a perspective view of a conventional secondary coil in which a high voltage diode is held on a bobbin.

[Explanation of symbols]

 11 Ignition coil 13 Case 14 Primary coil 15 Secondary coil 16 Iron core 18 Low voltage terminal 19 High voltage tower 20 High voltage diode 21 Connection conductor 23 High voltage diode input side electrode 24 High voltage diode output side electrode 26 Coil storage chamber 29 Secondary coil Bobbin 30 Terminal terminal of secondary coil 33 Insulation material

Claims (2)

[Scope of utility model registration request] 1. A case is provided with a primary coil, a secondary coil, an iron core magnetically coupling the primary coil and the secondary coil, and a high voltage diode for blocking a voltage generated in the secondary coil except at an ignition timing, In an ignition coil for an internal combustion engine that boosts the voltage supplied from the low-voltage terminal connected to the primary coil and takes it out from the high-voltage output terminal via the high-voltage diode connected to the secondary coil, in the high-voltage tower of the case where the high-voltage output terminal is installed An ignition coil for an internal combustion engine, comprising a high-voltage diode, wherein an input side of the high-voltage diode is electrically connected to a secondary coil via a connecting conductor. 2. An input side electrode is provided at one end of the high voltage diode,
The output side electrode is integrally formed at the other end, the high voltage diode is loaded into the high voltage tower with the input side electrode protruding inside the case, and the connecting conductor and the connecting part for connecting to the input side electrode are connected. An engaging part that connects to the secondary coil side is formed, and a terminal terminal electrically connected to the secondary coil is provided on the bobbin of the secondary coil, and when this bobbin is put in a predetermined position in the case, the terminal terminal is connected conductor. The position of the engaging part and the terminal terminal, and the position of the connecting part and the input side electrode are respectively set so that the connecting part of the connecting conductor is connected to the input side electrode of the high voltage diode. The ignition coil for an internal combustion engine according to claim 1, wherein an insulating material is injected and fixed in the case in a state where the terminal terminal is engaged with the engaging portion and the connecting portion is connected to the input side electrode.