阅读说明：本技术 一种减少火花塞接线端子接触电阻的方法及火花塞 (Method for reducing contact resistance of spark plug wiring terminal and spark plug ) 是由 陈小双 李耀 于 2020-04-20 设计创作，主要内容包括：一种减少火花塞接线端子接触电阻的方法及火花塞,包括：绝缘体、中心电极、电阻和接线端子,接线端子分成接线端子主体和接线端子帽两部分,分别加工成型。接线端子主体通过高温装配工序先装配在绝缘体中,然后在常温状态下通过焊接或铆接,将接线端子帽安装在接线端子主体后端,使接线端子帽得以避开高温装配工序,避免在接线端子帽表面形成氧化层,以减少接线端子帽与点火线圈接线端子之间的接触电阻。保证发动机怠速工况下能够可靠点火,避免了发动机怠速抖动。本发明的接线端子帽采用旋转体形状,既便于加工,又能够减轻接线端子帽重量。(A method of reducing contact resistance of a terminal of a spark plug and a spark plug comprising: insulator, center electrode, resistance and binding post, binding post divide into binding post main part and binding post cap two parts, machine-shaping respectively. The binding post main part assembles earlier in the insulator through high temperature assembly process, then through welding or riveting under normal atmospheric temperature state, installs the binding post cap at binding post main part rear end, makes the binding post cap can avoid high temperature assembly process, avoids forming the oxide layer on binding post cap surface to reduce the contact resistance between binding post cap and the ignition coil binding post. The ignition device can reliably ignite under the idle working condition of the engine, and the idle shaking of the engine is avoided. The wiring terminal cap adopts a rotating body shape, so that the processing is convenient, and the weight of the wiring terminal cap can be reduced.)

1. A method of reducing contact resistance of a terminal of a spark plug, comprising: separating the connecting terminal (3) into: the wiring terminal main body (31) and the wiring terminal cap (32) are respectively machined and molded, the wiring terminal main body (31) is assembled in the insulator (1) at a high temperature, and the wiring terminal cap (32) is installed at the rear end of the wiring terminal main body (31) at a normal temperature so as to avoid an oxide layer (33) from being formed on the surface of the wiring terminal cap (32).

2. The method of claim 1, wherein: the terminal cap (32) is connected with the terminal body (31) in a welding or riveting mode.

3. The method of claim 2, wherein: the wiring terminal cap (32) is formed by adopting metal blocks to be subjected to cold heading to form a cold heading terminal cap (5).

4. The method of claim 2, wherein: the wiring terminal cap (32) is formed by punching a metal sheet to form a punching terminal cap (6).

5. A spark plug comprising an insulator (1) and a terminal block (3), characterized in that: the wiring terminal (3) comprises a wiring terminal main body (31) and a wiring terminal cap (32) which are formed by separate processing, the wiring terminal main body (31) is arranged in the insulator (1) in a high-temperature state, and the wiring terminal cap (32) is arranged at the rear end of the wiring terminal main body (31) in a normal-temperature state.

6. The spark plug of claim 5, wherein: the terminal cap (32) is in the shape of a rotator.

7. The spark plug of claim 6, wherein: the rotating body is columnar, cylindrical, cup-shaped or cap-shaped.

8. The spark plug of claim 6, wherein: the weight of the wiring terminal cap (32) is less than or equal to 0.8 g.

9. The spark plug of claim 8, wherein: the outer diameter (D) of the terminal cap (32) is less than or equal to 8 mm, and the height (H) of the terminal cap is less than or equal to 6 mm.

Technical Field

The invention relates to a spark plug, in particular to a method for reducing contact resistance of a wiring terminal of the spark plug and the spark plug.

Background

As shown in fig. 1 and 2: the center hole 11 of the insulator 1 of the Spark Plug (SP) of the automobile is generally provided with a resistor 2 to suppress electromagnetic disturbance generated to the outside when the Spark Plug (SP) operates. The resistance of this resistor 2 is typically 3k omega to 12k omega. However, since the assembling process of the Spark Plug (SP) has a high temperature heating process, the surface of the terminal cap 32 of the terminal 3 inevitably generates an oxide layer 33 having a non-uniform thickness, as shown in fig. 3. The oxide layer 33 is an insulator whose resistance hinders conduction between the terminal cap 32 and the ignition coil terminal 4, and the thicker the thickness of the oxide layer 33, the larger the resistance. The resistor is connected in series in an ignition loop of an engine ignition coil, so that the line loss is increased, and particularly, when the engine is in an idle working condition, the output voltage of the ignition coil is low, so that the ignition energy of a Spark Plug (SP) is insufficient, the engine cannot be reliably ignited, and the problem of idle speed jitter of the engine is caused.

Through patent retrieval, the following patents mainly exist, which have a certain relationship with the invention:

1. the invention patent of China, having the application number of 'CN 201080040132.7', the application date of '2010.08.20', the publication number of 'CN 102484006A', the publication date of '2012.05.30', the name of 'spark plug' and the application name of 'Japanese Special ceramics corporation', comprises an insulator (2) having a shaft hole (4) extending in the direction of an axis (CL1) and a terminal electrode (6) inserted in the shaft hole (4). The terminal electrode (6) has a rod-shaped foot (6A) inserted through the rear end side of the shaft hole (4) and a head (6B) exposed from the rear end of the insulator (2). The tip of the leg (6A) of the terminal electrode (6) is fixed to the insulator (2), and the length of the leg (6A) along the axis (CL1) is 35mm or more. The center of gravity of the terminal electrode (6) is located inside the insulator (2). Thus, in the spark plug (1) having the terminal electrode (6) with the relatively long leg (6A), the terminal electrode (6) can be more reliably prevented from being broken.

2. Chinese patent application No. CN201410191258.4, application date "2014.05.07", publication No. CN104143766A ", publication date" 2014.11.12 ", entitled" spark plug ", and applicant" special ceramics corporation "provide a spark plug having a recess at the rear end of a terminal electrode and a nickel layer formed at the rear end of the terminal electrode, in which the corrosion resistance of the terminal electrode is sufficiently improved and the peeling of the nickel layer is more reliably suppressed. A spark plug (1) comprises: an insulator (2) having a shaft hole (4) that penetrates in the direction of the axis (CL 1); and a terminal electrode (6) having its rear end portion insulated from the insulator (2)The rear end of the shaft is inserted into the shaft hole (4) in an exposed state. A recessed part (6B) having the direction of the axis CL1 as the depth direction is provided at the rear end part of the terminal electrode (6). A nickel layer (35) is provided on the outer surface of the rear end portion of the terminal electrode (6). The nickel layer (35) has a thickness of 3 to 25 [ mu ] m, and the average cross-sectional area of crystal grains constituting the nickel layer (35) is 50 [ mu ] m in a cross section perpendicular to the outer surface of the nickel layer (35)²～500μm²。

3. The utility model provides a cup-base type spark plug, an ignition system and an automobile, which is a utility model patent with the application number of 'CN 201621292199.0', the application date of '2016.11.29', the publication number of 'CN 206195155U', the publication date of '2017.05.24', the name of 'cup-base type spark plug and ignition system and automobile', and the applicant of 'general automobile for gasoline limited company', the utility model provides a cup-base type spark plug and ignition system and automobile, the cup-base type spark plug comprises a screw rod, a ceramic body, a shell, a central electrode and a side electrode; the central electrode is connected with the connecting end of the screw rod; the ceramic body is sleeved on the central electrode and the screw rod; the shell is sleeved on the ceramic body and is positioned at the connecting end of the screw rod and the connecting position of the central electrode; the first end of the side electrode is fixed on the shell, the second end and the central electrode form a spark plug gap, the free end of the screw rod is provided with an end head used for being in contact with an ignition coil, and the end head protrudes out of the ceramic body; the end head is provided with a groove for embedding a spiral spring in the ignition coil.

4. The utility model discloses a utility model patent of "CN 201620688305.0", application date is "2016.07.04", publication number is "CN 205863640U", publication date is "2017.01.04", the name is "a spark plug with cup-shaped binding post", the applicant is "taki xiang torch spark plug finial responsibility company", this utility model includes binding post and ceramic pole, binding post inlays in the ceramic pole, the ceramic pole is stretched out to binding post's end top, its characterized in that, the ceramic pole is the polished rod of extension type, binding post is T font binding post; the end rod of the T-shaped wiring terminal is inserted into the ceramic rod, the head of the T-shaped wiring terminal is an end top, an inward concave wiring terminal groove is formed in the center of the end top, and the wiring terminal groove is a regular frustum blind hole. The utility model discloses an increase the length of ceramic rod, make creepage distance and creepage voltage on the spark plug all increase to the flashover phenomenon of effectual reduction spark plug prolongs ignition system's life.

None of the above patents relate to the oxide layer of the spark plug terminal and to the contact resistance between the spark plug terminal and the ignition coil terminal.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: aiming at the defects that a connecting terminal in the prior art has a thick oxide layer and causes large contact resistance between the connecting terminal of the spark plug and the connecting terminal of the ignition coil, a method for reducing the contact resistance of the connecting terminal of the spark plug and the spark plug are provided.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a method of reducing contact resistance of a terminal of a spark plug: separating the terminal into: the wiring terminal main body and the wiring terminal cap are respectively machined and formed, the wiring terminal main body is assembled in the insulator at a high temperature, and the wiring terminal cap is installed at the rear end of the wiring terminal main body at a normal temperature so as to avoid an oxide layer from being formed on the surface of the wiring terminal cap and reduce the contact resistance between the spark plug wiring terminal and the ignition coil wiring terminal.

Further, the terminal cap is connected with the terminal body in a welding or riveting mode so as to reduce the connection resistance between the terminal cap and the terminal.

Furthermore, the terminal cap is formed by adopting metal blocks to be subjected to cold heading to form the cold heading terminal cap, and the processing mode is high in efficiency and low in cost.

Furthermore, the wiring terminal cap is formed by punching a metal sheet to form a punched terminal cap, and the processing mode saves materials and reduces the weight.

The invention also relates to a spark plug which comprises an insulator and a wiring terminal, wherein the wiring terminal comprises a wiring terminal main body and a wiring terminal cap which are formed by processing separately, the wiring terminal main body is arranged in the insulator in a high-temperature state, and the wiring terminal cap is arranged at the rear end of the wiring terminal main body in a normal-temperature state. Because the wiring terminal adopts a split structure, the wiring terminal cap can avoid a high-temperature assembly process, and an oxide layer is prevented from being formed on the surface of the wiring terminal cap, so that the contact resistance between the wiring terminal cap and the wiring terminal of the ignition coil is reduced.

Furthermore, the wiring terminal cap is in a shape of a rotator, so that the processing is convenient, and the weight of the wiring terminal cap can be reduced.

Further, the rotating body is columnar, cylindrical, cup-shaped or cap-shaped.

Furthermore, the weight of the wiring terminal cap is less than or equal to 0.8 g, so that the anti-seismic performance is improved.

Furthermore, the outer diameter of the wiring terminal cap is less than or equal to 8 mm, and the height of the wiring terminal cap is less than or equal to 6 mm.

The invention has the beneficial effects that: the binding post of spark plug has adopted split type structure, separately does with binding post: the wiring terminal main part and the wiring terminal cap are respectively machined and formed, the wiring terminal main part is assembled in the insulator in a high-temperature state, then the wiring terminal cap is installed at the rear end of the wiring terminal main part through welding or riveting in a normal-temperature state, so that the wiring terminal cap can avoid a high-temperature assembly process, an oxide layer is prevented from being formed on the surface of the wiring terminal cap, and the contact resistance between the wiring terminal cap and the ignition coil wiring terminal is reduced. The terminal block cap adopts a rotator shape, which is convenient for processing and can reduce the weight of the terminal block cap.

Drawings

FIG. 1 is a schematic view of a spark plug construction;

FIG. 2 is a schematic cross-sectional view of a spark plug;

fig. 3 is a schematic partial cross-sectional view of the terminal;

FIG. 4 is a partial cross-sectional view schematically showing embodiment 1;

FIG. 5 is a partial cross-sectional view schematically showing embodiment 2;

FIG. 6 is a partial cross-sectional view of embodiment 3;

FIG. 7 is a schematic sectional view of a part of embodiment 4;

in the figure: SP-spark plug, 1-insulator, 11-center hole, 2-resistor, 3-connecting terminal, 31-connecting terminal body, 32-connecting terminal cap, 33-oxide layer, 34-welding melt, 35-rivet joint, 4-ignition coil terminal, 5-cold heading terminal cap, 6-stamping terminal cap.

Detailed Description

The invention is further described by the following specific embodiments in conjunction with the attached drawings:

as shown in fig. 3: an insulator 1 of the spark plug SP is provided with a center hole 11, a center electrode, a resistor 2 and a wiring terminal 3 are arranged in the center hole 11, the front end of the wiring terminal 3 is a wiring terminal main body 31 which is arranged in the center hole 11 and is electrically connected with the resistor 2, and the rear end of the wiring terminal 3 protrudes out of the center hole 11 to form a wiring terminal cap 32 which is electrically connected with a wiring terminal 4 of an ignition coil. The terminal body 31 and the terminal cap 32 are generally integrally formed. Since the spark plug SP is assembled by a high-temperature assembling process at a temperature of 850 ℃, the surface of the terminal cap 32 is inevitably provided with the oxide layer 33 having a non-uniform thickness. The oxide layer 33 is an insulator, and the resistance of the oxide layer hinders conduction between the terminal 3 and the ignition coil terminal 4, and the resistance increases as the thickness of the oxide layer 3 increases.

The invention discloses a method for reducing contact resistance of a connecting terminal of a spark plug, which comprises the following steps: the wiring terminal body 31 of the wiring terminal 3 and the wiring terminal cap 32 of the wiring terminal 3 are separately processed and formed, and the wiring terminal cap 32 is formed by adopting metal block cold heading or metal sheet punch forming.

The center electrode, the resistor 2 and the terminal body 31 are first fitted in this order in the center hole 11 of the insulator 1. The front end of the resistor 2 is contacted with the rear end of the central electrode to realize electric connection; the front end of the wiring terminal main body 31 is contacted with the rear end of the resistor 2 to realize electric connection; the rear end of the terminal body 31 protrudes through the center hole 11 to expose the rear end of the insulator 1. The center electrode, the resistor 2, and the terminal main body 31 are cured and sealed in the center hole 11 at a high temperature (temperature 850 ℃).

Then, the terminal cap 32 is fixedly connected to the rear end of the terminal body 31 in a welding or riveting manner at a normal temperature, so that the terminal cap 32 can avoid a high-temperature assembly process, the formation of a surface oxide layer 33 on the terminal cap 32 in the high-temperature assembly process is avoided, and finally, the contact resistance between the terminal cap 32 and the ignition coil terminal 4 is reduced.

The following table shows measured contact resistance data for several different terminal caps 32, from which it can be seen that: the contact resistance of the soldered or riveted terminal cap 32 is much lower than that of the conventional integrally molded terminal cap 32. The ignition device ensures reliable ignition under the idle working condition of the engine and avoids idle shaking of the engine.

The terminal cap 32 of the present invention is in the shape of a cylindrical, tubular, cup-shaped or cap-shaped rotor, which facilitates processing and reduces the weight of the terminal cap 32. The weight of the terminal cap 32 is less than or equal to 0.8 g, the outer diameter D is less than or equal to 8 mm, and the height H is less than or equal to 6 mm. So as to reduce the inertia force of the terminal cap 32 when the spark plug vibrates, and avoid the insulator 1 from cracking and damaging due to too large inertia force, thereby improving the anti-seismic performance of the spark plug.

The terminal cap 32 can be made into a cold heading terminal cap 5 by adopting a metal block cold heading forming mode; or the terminal cap 6 is made by punching and molding a metal sheet. So as to improve the processing efficiency and reduce the processing cost.