CN106128727B - A kind of automobile ignition coil static iron core - Google Patents

Abstract

The invention discloses a static iron core for an automobile ignition coil. The shape of the soft magnetic core is a cylinder; the composition and content of the soft magnetic core include Ni 4-6%, Mo 2-3%, Co 0.2-0.5%, Cd 0.2-0.4%, Mn 0.1-0.2%, Ba 0.1-0.3%, phenolic resin 1-2%, and the balance is iron. The soft magnetic core is prepared according to the following process. The preparation process includes steps such as vacuum smelting, primary crushing, pickling, secondary crushing, fine crushing, dehydration, drying, screening, annealing treatment, insulation coating, compression molding, and heat treatment. After adopting the above components and preparation process, the soft magnetic core is vertically molded and pressed in one piece, with low molding pressure, higher molding density, resistivity, initial magnetic permeability, saturation magnetic induction and spectral characteristics, and low high-frequency loss .

Description

Static iron core for automobile ignition coil

technical field

The invention relates to an ignition system of an automobile engine, in particular to a static iron core for an automobile ignition coil.

Background technique

In the ignition system of an automobile engine, the ignition coil is an executive component that provides ignition energy for igniting the air and fuel mixture in the engine cylinder. It is based on the principle of electromagnetic induction, by turning off and on the primary circuit of the ignition coil, the current in the primary circuit increases and then suddenly decreases, so that the high voltage required for ignition is induced in the secondary. The ignition coil can be thought of as a special pulse transformer that converts a low voltage of 10-12V into a voltage of 25000V or higher. At present, the more typical one is the open magnetic circuit pen type ignition coil, which includes an open iron core forming the magnetic circuit of the ignition coil, a secondary copper wire winding wound on the iron core, and a primary coil winding wound outside the secondary winding. Mainly the current through the primary coil winding is stored as a magnetic field. When the current of the primary coil winding is cut off suddenly (disconnecting the ground terminal of the circuit through the power transistor), the magnetic field decays, causing the secondary coil winding to generate an induced electromotive force, and the voltage of the induced electromotive force is sufficient to discharge the pencil coil, which we call inductive discharge type ignition. There is also a capacitive discharge ignition system, commonly referred to as CDI ignition.

The iron core in the ignition coil is the core component, and the inductance of the iron core directly affects the ignition energy of the coil.

The Chinese invention patent application with the application number 201310273684.8 published on January 1, 2014, the name of its invention is "A core set for automobile spark plug igniter", in which the first core is made of multi-layer electrical steel strips. The segmented iron core stacked and connected together is folded into a closed-shaped annular iron core; each layer of punched sheet material is composed of 4 segments and connecting areas, the first segment and the second segment, the second segment The first segment and the third segment, and the third segment and the fourth segment are connected by a connecting area, and the opposite positions on the outside of the first segment and the fourth segment are respectively designed as bosses and grooves for hinged lock Tight; the grain direction of the electrical steel strip is consistent with the length direction of the four segments; the second iron core is installed in the above-mentioned first iron core connected into a ring, and it is also made of multi-layer electrical steel strips It is laminated, and its length direction is consistent with the grain direction of electrical steel. Therefore, it has the advantages of material saving and cost reduction.

The Chinese invention patent application with the application number "201210485879.4" published on February 27, 2013 is titled "A Method for Automated Stamping and Counting Lamination Riveting Forming of Auto Ignition Coil Core Progressive Die", which It is mainly composed of a punch press riveting machine, a single-chip computer and an electric control cabinet, a fixed tape unwinding device, and a rewinding device for the remaining material tape. There is a single-chip computer in the electric control cabinet, and a proximity sensor switch and a solenoid valve are installed on the progressive die. Use the proximity sensor switch for memory counting, set the required value, set the output signal by the value of the single-chip microcomputer, control the solenoid valve, the output of the solenoid valve controls the cylinder to realize the lamination counting, and set an error-proof correction sensor in the progressive die, that is, error-proofing Correct the button, control the punch press and progressive die to stop working, and restart the continuous punching work after the equipment is adjusted correctly. The invention improves the production efficiency by 10 times, only needs one person to operate, and the qualified rate of the product is increased from 85%-90% to 99.7%, which reduces the production cost.

In the above two patent applications, the iron cores of the automobile ignition coils are all prepared by stacking silicon steel sheets and then riveting and forming. When the silicon steel sheets are laminated and riveted, the laminations are easily dislocated, and there are riveting gaps and riveting damage between the sheets, which leads to low resistivity, initial magnetic permeability and low magnetic induction of the automobile ignition coil core. , high loss, poor high-frequency response, and small inductance of the iron core, resulting in low ignition energy of the coil.

In addition, at present, the manufacturing process of the static iron core adopts the horizontal fixed pressing method. The specific process is: the die is fixed on the formwork, iron powder is installed in the die, and the upper punch and the lower punch are used to press together. The punch is half-cylindrical and fixed, the die is also fixed, and the upper punch is also half-cylindrical, and the pressing process is completed by moving the upper punch up and down. Because the whole iron core is composed of two semi-cylindrical shapes, there is always a certain interface between the two semi-circles, which cannot form a complete circle, so that the inductance of the iron core is small, resulting in a small ignition energy of the coil. At the same time, the cross section of the iron core is similar to an ellipse, and there is a wide seam in the middle, and the surface finish is poor. The iron core is made of pure iron powder, which has low resistivity, low saturation magnetic induction, large loss, and poor high-frequency response.

Contents of the invention

The technical problem to be solved by the present invention is to provide a static iron core for an automobile ignition coil, which is integrally formed and pressed vertically, with low molding pressure and higher Excellent molding density, resistivity, initial permeability, saturation magnetic induction and spectral characteristics, and low high-frequency loss. In addition, the surface finish of the static iron core is good, and the cross section is a perfect circle, so that the iron core of a certain size has greater inductance and provides higher ignition energy for the coil.

In order to solve the problems of the technologies described above, the technical solution adopted in the present invention is:

A static iron core for an automobile ignition coil, the shape of the static iron core is a cylinder; the composition and content of the static iron core, by weight percentage, include Ni 4-6%, Mo 2-3%, Co 0.2-0.5 %, Cd 0.2-0.4%, Mn 0.1-0.2%, Ba 0.1-0.3%, phenolic resin 1-2%, and the balance is mainly iron. The static iron core is prepared according to the following process.

The first step is vacuum smelting: the iron block, nickel block and molybdenum block are put into the vacuum induction furnace according to the ratio for smelting and casting.

The second step, primary crushing: the alloy that has been smelted and casted in the first step is initially crushed using a pulverizer.

The third step, pickling: the alloy pulverized in the second step is pickled with a metal surface pickling solution.

The fourth step, medium crushing: under the nitrogen protection atmosphere, first put the alloy that was crushed in the second step into the winnowing sand mill, and then add Co, Cd, Mn and Ba in sequence according to the proportion, and start the winnowing sand Mill, crushing in progress.

The fifth step, fine crushing: under the protective atmosphere of alcohol, the crushed alloy is finely crushed again with a winnowing sand mill.

The sixth step, deliquoring and drying: use a centrifuge to deliquify the finely pulverized alloy powder; then use an oven to dry the deliquored alloy powder.

The seventh step, sieving: use a vibrating sieve to sieve the alloy powder that has been deliquored and dried.

The eighth step, annealing treatment: under the mixed atmosphere of hydrogen and nitrogen, the sieved alloy powder is annealed in a push boat furnace.

The ninth step, insulation coating: add the annealed alloy powder into the insulation coating mixing tank, then add phenolic resin, mica powder and lubricant according to the ratio, heat, stir and coat the insulation coating mixing tank.

The tenth step, pressing and forming: using a forming press, adopting a vertical and vertical pressing method, so that the cylindrical static iron core is integrally formed and pressed.

The eleventh step, heat treatment: the static iron core pressed and formed in the tenth step is subjected to heat treatment.

In the eighth step, the temperature of the annealing treatment is 800-1200° C., and the temperature is kept for 2-4 hours.

In the eleventh step, the heat treatment temperature is 120-200° C., and the temperature is kept for 4-6 hours.

The heating temperature of the insulating and coating mixing barrel is 55-65°C. The insulating and covering mixing barrel includes an inner barrel, an outer barrel and a heating device wrapped around the outer barrel.

When the cylindrical static iron core is integrally molded and pressed, the molding pressure is 6-12T/cm ² , and the molding temperature is 60-200°C.

After the above components and preparation process are adopted in the present invention, the static iron core is integrally formed and pressed vertically, with low forming pressure, higher forming density, resistivity, initial magnetic permeability, saturation magnetic induction and spectral characteristics, and low loss . In addition, the surface finish of the static iron core is good, and the cross section is a perfect circle, so that the iron core of a certain size has greater inductance and provides higher ignition energy for the coil.

detailed description

The present invention will be further described in detail with respect to specific preferred embodiments.

Example 1

A static iron core for an automobile ignition coil, the shape of the static iron core is a cylinder; the composition and content of the static iron core, by weight percentage, include Ni 4%, Mo 2%, Co 0.2%, Cd 0.2%, 0.1% of Mn, 0.1% of Ba, 1% of phenolic resin, and the balance are mainly iron. The static iron core is prepared according to the following process.

The first step is vacuum smelting: the iron block, nickel block and molybdenum block are put into the vacuum induction furnace according to the ratio for smelting and casting.

The second step, primary crushing: the alloy that has been smelted and casted in the first step is initially crushed using a pulverizer.

The third step, pickling: the alloy pulverized in the second step is pickled with a metal surface pickling solution.

The fourth step, medium crushing: under the nitrogen protection atmosphere, first put the alloy that was crushed in the second step into the winnowing sand mill, and then add Co, Cd, Mn and Ba in sequence according to the proportion, and start the winnowing sand Mill, crushing in progress.

The fifth step, fine crushing: under the protective atmosphere of alcohol, the crushed alloy is finely crushed again with a winnowing sand mill.

The sixth step, deliquoring and drying: use a centrifuge to deliquify the finely pulverized alloy powder; then use an oven to dry the deliquored alloy powder.

The seventh step, sieving: use a vibrating sieve to sieve the alloy powder that has been deliquored and dried.

The eighth step, annealing treatment: in a hydrogen-nitrogen mixed atmosphere, anneal the sieved alloy powder in a boat furnace. The temperature of the annealing treatment is 800-1200° C., and the temperature is kept for 2-4 hours.

The ninth step, insulation coating: add the annealed alloy powder into the insulation coating mixing tank, then add phenolic resin, mica powder and lubricant according to the ratio, heat, stir and coat the insulation coating mixing tank. The heating temperature of the insulation-coated mixing barrel is 55-65°C. The insulation-coated mixing barrel includes an inner barrel, an outer barrel and a heating device wrapped around the outer barrel. The inner barrel can not only rotate by itself, but also revolve with the outer barrel.

The tenth step, pressing and forming: using a forming press, adopting a vertical and vertical pressing method, so that the cylindrical static iron core is integrally formed and pressed. When the cylindrical static iron core is integrally molded and pressed, the molding pressure is 6-12T/cm ² , and the molding temperature is 60-200°.

The eleventh step, heat treatment: the static iron core pressed and formed in the tenth step is subjected to heat treatment. The temperature of the heat treatment is 120-200° C., and the temperature is kept for 4-6 hours.

Example 2

A static iron core for an automobile ignition coil, the shape of the static iron core is a cylinder; the composition and content of the static iron core, by weight percentage, include Ni 4-6%, Mo 2.5%, Co 0.3%, Cd 0.3 %, Mn 0.15%, Ba 0.2%, phenolic resin 1.5%, and the balance is mainly iron. The static iron core is prepared according to the following process.

The first step is vacuum smelting: the iron block, nickel block and molybdenum block are put into the vacuum induction furnace according to the ratio for smelting and casting.

The second step, primary crushing: the alloy that has been smelted and casted in the first step is initially crushed using a pulverizer.

The third step, pickling: the alloy pulverized in the second step is pickled with a metal surface pickling solution.

The fourth step, medium crushing: under the nitrogen protection atmosphere, first put the alloy that was crushed in the second step into the winnowing sand mill, and then add Co, Cd, Mn and Ba in sequence according to the proportion, and start the winnowing sand Mill, crushing in progress.

The fifth step, fine crushing: under the protective atmosphere of alcohol, the crushed alloy is finely crushed again with a winnowing sand mill.

The sixth step, deliquoring and drying: use a centrifuge to deliquify the finely pulverized alloy powder; then use an oven to dry the deliquored alloy powder.

The seventh step, sieving: use a vibrating sieve to sieve the alloy powder that has been deliquored and dried.

The eighth step, annealing treatment: in a hydrogen-nitrogen mixed atmosphere, anneal the sieved alloy powder in a boat furnace. The temperature of the annealing treatment is 800-1200° C., and the temperature is kept for 2-4 hours.

The ninth step, insulation coating: add the annealed alloy powder into the insulation coating mixing tank, then add phenolic resin, mica powder and lubricant according to the ratio, heat, stir and coat the insulation coating mixing tank. The heating temperature of the insulation-coated mixing barrel is 55-65°C. The insulation-coated mixing barrel includes an inner barrel, an outer barrel and a heating device wrapped around the outer barrel. The inner barrel can not only rotate by itself, but also revolve with the outer barrel.

The tenth step, pressing and forming: using a forming press, adopting a vertical and vertical pressing method, so that the cylindrical static iron core is integrally formed and pressed. When the cylindrical static iron core is integrally molded and pressed, the molding pressure is 6-12T/cm ² , and the molding temperature is 60-200°C.

The eleventh step, heat treatment: the static iron core pressed and formed in the tenth step is subjected to heat treatment. The temperature of the heat treatment is 120-200° C., and the temperature is kept for 4-6 hours.

Example 3

A static iron core for an automobile ignition coil, the shape of the static iron core is a cylinder; the composition and content of the static iron core, by weight percentage, include Ni 6%, Mo 3%, Co 0.5%, Cd 0.4%, 0.2% of Mn, 0.3% of Ba, 2% of phenolic resin and the balance are mainly iron. The static iron core is prepared according to the following process.

The first step is vacuum smelting: the iron block, nickel block and molybdenum block are put into the vacuum induction furnace according to the ratio for smelting and casting.

The second step, primary crushing: the alloy that has been smelted and casted in the first step is initially crushed using a pulverizer.

The third step, pickling: the alloy pulverized in the second step is pickled with a metal surface pickling solution.

The fourth step, medium crushing: under the nitrogen protection atmosphere, first put the alloy that was crushed in the second step into the winnowing sand mill, and then add Co, Cd, Mn and Ba in sequence according to the proportion, and start the winnowing sand Mill, crushing in progress.

The fifth step, fine crushing: under the protective atmosphere of alcohol, the crushed alloy is finely crushed again with a winnowing sand mill.

The sixth step, deliquoring and drying: use a centrifuge to deliquify the finely pulverized alloy powder; then use an oven to dry the deliquored alloy powder.

The seventh step, sieving: use a vibrating sieve to sieve the alloy powder that has been deliquored and dried.

The eighth step, annealing treatment: in a hydrogen-nitrogen mixed atmosphere, the sieved alloy powder is annealed in a boat furnace at a temperature of 800-1200° C. and kept for 2-4 hours.

The ninth step, insulation coating: add the annealed alloy powder into the insulation coating mixing tank, then add phenolic resin, mica powder and lubricant according to the ratio, heat, stir and coat the insulation coating mixing tank. The heating temperature of the insulation-coated mixing barrel is 55-65°C. The insulation-coated mixing barrel includes an inner barrel, an outer barrel and a heating device wrapped around the outer barrel. The inner barrel can not only rotate by itself, but also revolve with the outer barrel.

The tenth step, pressing and forming: using a forming press, adopting a vertical and vertical pressing method, so that the cylindrical static iron core is integrally formed and pressed. When the cylindrical static iron core is integrally molded and pressed, the molding pressure is 6-12T/cm ² , and the molding temperature is 60-200°C.

The eleventh step, heat treatment: the static iron core pressed and formed in the tenth step is subjected to heat treatment. The temperature of the heat treatment is 120-200° C., and the temperature is kept for 4-6 hours.

Test verification

Take the static iron core for the automobile ignition coil of this application, taking µe60 as an example, use the same LCR digital inductance meter, density tester and power consumption meter to test the initial magnetic permeability, molding density and magnetic induction.

At the same time, the existing technology, such as the silicon steel sheet in the background technology, is used as a comparative example.

The test results are as follows:

initial permeability Molding density g/cm ³ 400KHz specific total power consumption Ps (W/kg) Example 1 7500 7.6 30.5 Example 2 7800 7.8 28.2 Example 3 6700 7.3 31 Comparative example 5600 —— 38

Through the above tests, it can be seen that the present invention has obvious advantages and is convenient for wide popularization and application.

The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be carried out to the technical solutions of the present invention. These equivalent transformations All belong to the protection scope of the present invention.

Claims (5)

1. a kind of automobile ignition coil static iron core, static iron core are shaped as cylinder；It is characterized in that：The component of static iron core and Content, by weight percentage, including：

Ni 4-6%；

Mo 2-3%；

Co 0.2-0.5%；

Cd 0.2-0.4%；

Mn 0.1-0.2%；

Ba 0.1-0.3%；

Phenolic resin 1-2%；

Surplus is mainly iron；

Static iron core is prepared according to following technique：

The first step, vacuum melting：By iron block, nickel block and molybdenum block according to proportioning, put into and melting casting is carried out in vaccum sensitive stove；

Second step, just crush：The alloy that first step melting casting is completed, preliminary crushing is carried out using pulverizer；

3rd step, pickling：The alloy crushed at the beginning of second step is subjected to pickling using metal surface pickle；

4th step, middle crushing：In the case where nitrogen protective atmosphere encloses, first the alloy crushed at the beginning of second step is put into selection by winnowing sand mill, then According to proportioning, Co, Cd, Mn and Ba are sequentially added, selection by winnowing sand mill is opened, is crushed in progress；

5th step, it is finely divided：Under protected alcohol atmosphere, the alloy of crushing is carried out using selection by winnowing sand mill again finely divided；

6th step, take off liquid, drying：Using centrifuge to finely divided alloyed powder, de- liquid is carried out；Baking oven is recycled by after de- liquid Alloyed powder is dried；

7th step, screening：The alloyed powder completed to taking off liquid drying is sieved using vibratory sieve；

8th step, annealing：Under hydrogen nitrogen mixed gas atmosphere, the alloyed powder use for sieving completion is pushed away into boat stove and carried out at annealing Reason；

9th step, insulating wrapped：It will make annealing treatment in the alloyed powder addition insulating wrapped agitator completed, added according still further to proportioning Phenolic resin, mica powder and lubricant, insulating wrapped agitator carry out heating stirring and cladding；

Tenth step, it is compressing：Using moulding press, by the way of vertically vertically suppressing, make the static iron core one of cylinder Shaping compacting；

11st step, heat treatment：The compressing static iron core of tenth step is heat-treated.

2. automobile ignition coil static iron core according to claim 1, it is characterised in that：In 8th step, at annealing The temperature of reason is 800-1200 DEG C, is incubated 2-4 hours.

3. automobile ignition coil static iron core according to claim 1, it is characterised in that：In 11st step, at heat The temperature of reason is 120-200 DEG C, is incubated 4-6 hours.

4. automobile ignition coil static iron core according to claim 1, it is characterised in that：The insulating wrapped agitator Heating-up temperature is 55-65 DEG C, and insulating wrapped agitator includes interior bucket, outer barrel and the heater for being coated on outer barrel surrounding, interior bucket Can rotation, and can revolved round the sun with outer barrel.

5. automobile ignition coil static iron core according to claim 1, it is characterised in that：Cylinder static iron core one into Briquetting pressure when type is suppressed is 6-12T/cm², forming temperature is 60-200 DEG C.