KR100271720B1 - Electrode tip - Google Patents

Abstract

PURPOSE: An electrode tip for use in a spark plug and method for contacting the electrode tip to an electrode of the spark plug is provided to improve the performance of an engine, the durability of an igniter, the welding of the electrode tip about the electrode, and the durability of the electrode by easily igniting of a mixer and preventing damage of an electric device system due to high voltage. CONSTITUTION: A welding unit(31) is formed around the upper half of a main frame. A spot welding projection(33) is formed on the center of the upper face of the main frame. An antiphlogistic preventing groove(35) is formed on the lower face of the main frame in the form selected from a group including a cross-shape having a section of V-letter and a lattice-shape having a circle and a section of V-letter.

Description

Spark tip electrode tip and the method for bonding the electrode tip to the spark plug electrode

The present invention relates to an electrode tip for a spark plug to be bonded to the center electrode and the ground electrode of the spark plug and a method for bonding the electrode tip to the electrode of the spark plug, in particular generated by a discharge generated between the center electrode and the ground electrode. The spark is turned off to deteriorate the ignition of the mixer, that is, to reduce the so-called anti-inflammatory action, and the electrode tip for the spark plug and the electrode tip having excellent adhesion to the center electrode and the ground electrode and the electrode tip to the electrode of the spark plug It relates to a method of bonding.

The ignition device is a high-voltage current generated from the ignition coil is applied to the center electrode of the spark plug to generate an electric spark by the discharge in the gap between the center electrode and the ground electrode to ignite the mixer supplied into the combustion chamber through the intake valve, Usually, it consists of a battery, an ignition coil, an ignition switch, a distributor, a high voltage cable, a spark plug, and the like.

The spark plug includes a central electrode, a central axis for introducing a high voltage current generated from the ignition coil to the center electrode, an insulator insulated from and surrounding the central axis, and a cylinder head surrounding the insulator and the electrode to protect the insulator and the electrode. It includes a housing having a male screw portion to be screwed, and a ground electrode which is bent to the lower side of the male screw portion of the housing in contact with the engine and disposed to face the center electrode at a predetermined interval. Although the electrodes are usually made of nickel alloy having excellent melting resistance, high temperature corrosion resistance, and spark consumption in a high temperature combustion atmosphere, the core electrode is difficult to obtain a stable electric flame in the long term due to insufficient high temperature strength and ends its service life in a relatively short time. The electrode tips made of a noble metal such as platinum or a platinum-based alloy are usually bonded to surfaces corresponding to each other of the ground electrodes to improve durability.

Therefore, when the high-voltage current induced from the ignition coil is applied to the center electrode through the central axis, an electric flame is generated by the discharge between the electrode tips, so that the mixer of the combustion chamber is ignited and the explosion stroke is performed by flame propagation.

However, in the conventional spark plug, the precious metal electrode tips joined to the center electrode and the ground electrode are simply formed in the shape of a cylinder or a cuboid, as disclosed in Korean Patent Application Laid-Open Publication No. 98-6677, and the opposite sides of the electrode tips Due to the plane relationship, so-called anti-inflammatory action occurs. That is, a phenomenon occurs in which the electric flame generated by the discharge generated between the electrode tips is turned off to deteriorate the ignition of the mixer.

In addition, the electrode tips are bonded to improve the durability of the electrodes, but the conventional electrode tips are simply bonded to the center electrode and the ground electrode by spot welding, so that the bonding strength is weak and the electrode tips are peeled from the electrodes.

The present invention has been made to solve the conventional problems as described above, it is an object of the present invention to improve the ignition of the mixer by reducing the anti-inflammatory action and to provide an electrode tip for a spark plug excellent bonding.

Another object of the present invention is to provide a method of bonding the electrode tip to the electrode of the spark plug, which can improve the durability of the center electrode and the ground electrode by firmly bonding the electrode tip to the center electrode and the ground electrode.

1 is a cross-sectional view showing an electrode tip according to a first embodiment of the present invention.

FIG. 2 is a bottom view of FIG. 1.

3 is a cross-sectional view showing an electrode tip according to Embodiment 2 of the present invention.

4 is a bottom view of FIG. 3.

5 is a cross-sectional view showing an electrode tip according to a third embodiment of the present invention.

6 is a bottom view of FIG. 5.

7 is a partial cross-sectional view showing a state in which the electrode tip is bonded to the center electrode of the spark plug according to the first embodiment of the present invention.

8 is a partial cross-sectional view showing a state in which the electrode tip is bonded to the center electrode of the spark plug according to the second embodiment of the present invention.

9 is a partial cross-sectional view showing a state in which the electrode tip is bonded to the center electrode of the spark plug according to the third embodiment of the present invention.

10 is a partial cross-sectional view showing a state in which the electrode tip is bonded to the ground electrode of the spark plug according to the first embodiment of the present invention.

11 is a partial cross-sectional view showing a state in which the electrode tip is bonded to the ground electrode of the spark plug according to the second embodiment of the present invention.

12 is a partial cross-sectional view showing a state in which the electrode tip is bonded to the ground electrode of the spark plug according to the third embodiment of the present invention.

13A to 13D are views illustrating a process of welding an electrode tip to a center electrode according to Embodiment 1 of the present invention.

14A to 14C are views illustrating a process of welding an electrode tip to a center electrode according to Embodiment 3 of the present invention.

15 is a schematic partial front view of the spark plug welded to the center electrode and the ground electrode, respectively, according to the first embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

1: spark plug, 3: electrode tip,

4: center electrode, 5: ground electrode

7: spot welding machine, 9: laser welding machine,

31: welding rod, 33: spot welding protrusion,

35: anti-inflammatory groove, 71: spot welding electrode,

75, 95: pressure spring, 91: electrode fixing jig

In order to achieve the above object, the present invention is an electrode tip for a spark plug to be bonded to the center electrode or the ground electrode of the spark plug, the main body; A weld rod formed around the upper half of the main body; A spot welding protrusion formed at the center of the upper surface of the main body; It characterized in that it comprises an anti-inflammatory groove formed on the bottom surface of the main body in any one form selected from the group comprising a cross-shaped, circular and V-shaped cross section having a V-shaped cross section.

When the anti-corrosion groove is made of a cross-shaped cross-section having a V-shaped cross section or a lattice shape having a V-shaped cross section, the anti-glare groove is preferably formed entirely on the bottom of the main body. In addition, when the anti-corrosion groove is formed in a circular shape, the anti-corrosion groove is preferably formed in the center of the bottom surface of the body.

When the two electrode tips configured as described above are joined to the center electrode and the ground electrode so that the bottom faces each other, the flame flows when an electric flame occurs due to discharge between the two electrode tips bonded to the center electrode and the ground electrode. The flame nucleus, i.e., the size of the electric flame, is enlarged so that the mixer is easily ignited.

The present invention also relates to a main body, a weld strip formed around the upper half of the main body, a spot welding protrusion formed at the center of the upper surface of the main body, and a grating having a cross-shaped, circular and V-shaped cross section having a V-shaped cross section. A method of joining an electrode tip comprising an anti-inflammatory groove formed on the bottom surface of the main body to an electrode of a spark plug in any one form selected from the group including a die, the spot welding protrusion on an upper surface of the spot welding electrode of a spot welder. The first spot welding step of joining the spot welding protrusion and the bottom surface of the electrode by first placing the electrode tip of the spark plug so that the bottom face is in contact with the spot welding protrusion and spot welding the electrode tip. ; The center welding part, which is the junction between the electrode and the electrode tip, is formed by detaching an electrode having the electrode tip bonded by the primary spot welding from the spot welder and placing the electrode in a laser welding machine to radiate a laser beam to the welding electrode of the electrode tip to melt the welding electrode. and a laser beam welding step of increasing a nugget and a corona pond.

According to the present invention, it is preferable that a pressing spring is installed under the spot welding electrode of the spot welding machine which fixes the electrode tip to receive the force toward the electrode during the first spot welding.

Then, the laser beam is radiated to one side or both sides of the weldment, and it is preferable to rotate the laser beam radiating portion around the weldment or to rotate the electrode fixing jig fixing the electrode during the laser beam irradiation.

In addition, the pressure spring is preferably installed under the electrode fixing jig of the laser welding machine so that the electrode tip receives the force toward the center electrode in order to improve weldability and shorten the welding time.

According to the method of joining the electrode tip of the present invention configured as described above to the electrode of the spark plug, the double welding through the first spot welding and laser welding, the growth state of the center welding portion and the rim of the electrode tip and the junction is good Since it is induced, the bonding state of the electrode tip is excellent. In the case of primary spot welding, as well as during laser welding, pressing and welding the electrode and the electrode tip by the spring increases the pressing force, which promotes the melting of the joint and further promotes the growth of the central weld and the rim. To be excellent.

Other features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings.

Various embodiments of the electrode tip according to the present invention will be described with reference to FIGS. 1 to 12.

<Example 1>

An electrode tip according to Embodiment 1 of the present invention will be described with reference to FIGS. 1, 2, 7 and 10.

Reference numeral 3 is an electrode tip and is made of a noble metal such as platinum or a platinum-based alloy such as Pt-Ni, Pt-Ir or Pt-Pd.

As shown in Figs. 1 and 2, reference numeral 30 denotes the main body 30 of the electrode tip 3 according to the present invention. The weld seam 31 is formed around the upper end of the main body 30 so that the lower end of the main body 30 is a stepped portion having a smaller diameter than the weld seam 31. As will be described later, the welding teeth 31 are for a laser welding process, which is a process of attaching the electrode tip 3 to the center electrode 4 or the ground electrode 5 as shown in FIGS. 7 and 10. Is provided.

According to the first embodiment, the spot welding protrusions 33 are formed on the upper surface of the main body 30 so that the spot welding protrusions 33 protrude above the upper surface of the weld bar 31. The upper surface of the spot welding protrusion 33 is preferably made of a curved surface or the shape of the center protruding upward. As described above, if the upper surface of the spot welding protrusion 33 is formed as a curved surface, the electrode tip 3 may be bonded to the center electrode 4 of the spark plug 1 (see FIG. 15), as shown in FIG. 7. As shown in FIG. 10, in the spot welding for joining the ground electrode 5 of the spark plug 1, the contact cross section between the spot welding protrusion 33 and the electrode 4 or 5 becomes small, and thus, when energized. Since the heat of resistance increases, the junction between the spot welding protrusion 33 and the electrode 4 or 5 can be easily welded, which is advantageous for spot welding.

According to the first embodiment, as shown in FIGS. 1 and 2, a cross-shaped anti-corrosion preventing groove 35 having a V-shaped cross section is formed at the bottom of the main body 30. This anti-corrosion groove 35 is preferably formed over the entire bottom surface of the body (30).

The high-voltage current induced through the ignition coil to the center electrode 4 of the spark plug 1 formed by joining the electrode tip 3 having the cross-type anti-corrosion preventing groove 35 to the center electrode 4 and the ground electrode 5. When is applied through the central axis of the spark plug (1) generates an electric flame by the discharge. Since the electric flame is introduced into the anti-flame prevention groove 35, the flame nucleus, that is, the size of the electric flame is expanded and propagated radially through the anti-flame prevention groove 35, so that the anti-flaming action of the electric flame is turned off, so that the ignition of the mixer occurs easily. .

<Example 2>

An electrode tip according to Embodiment 2 of the present invention will be described with reference to FIGS. 3, 4, 8, and 11.

Except for the electrode tip 3 according to the second embodiment is a circular anti-inflammatory groove 35 is formed in the center of the bottom surface of the main body 30 as shown in Figs. Since it is the same as that of Example 1, the same code | symbol is attached | subjected about the same part as Example 1, and the detailed description here is abbreviate | omitted.

8 shows a state in which the electrode tip 3 according to the second embodiment is bonded to the center electrode 4, and FIG. 10 shows a state in which the electrode tip 3 according to the second embodiment is bonded to the ground electrode 5. Indicates.

<Example 3>

An electrode tip according to Embodiment 3 of the present invention will be described with reference to FIGS. 5, 6, 9, and 12.

Except that the electrode tip 3 according to the third embodiment is a circular anti-inflammatory groove 35 is formed in the center of the bottom surface of the main body 30 as shown in Figs. Since all are the same as one embodiment, the same parts as the above-described embodiment are denoted by the same reference numerals and detailed description thereof will be omitted.

9 shows a state in which the electrode tip 3 according to the third embodiment is bonded to the center electrode 4, and FIG. 12 shows a state in which the electrode tip 3 according to the third embodiment is bonded to the ground electrode 5. Indicates.

In Examples 1 to 3 described above, for the sake of convenience, the electrode tip 3 having the main body 30 having an outer circumferential surface having a substantially cylindrical surface is illustrated and described as an example. The shape of the welding teeth 31, the spot welding protrusion 33 and the anti-corrosion groove 35 can be applied as it is to the electrode tip having the main body as described above, all of these electrode tips are also within the scope of the present invention. Should be included.

Next, a method of joining the electrode tips 3 that are variously configured as described above with reference to FIGS. 13A to 13D to the center electrode 4 and the ground electrode 5 of the spark plug 1 will be described. Since the method of bonding the electrode tip 3 to the center electrode 4 and the method of bonding the electrode tip 3 to the ground electrode 5 are the same, for the sake of convenience, the electrode tip 3 is bonded to the center electrode 4. Only the method will be described.

First, in order to perform the first spot welding, the electrode tip 3 is placed on the spot welding electrode 71 upper surface of the spot welder 7 as shown in FIG. 13A. An insertion groove 73 is formed at the center of the upper surface of the spot welding electrode 71 so that the stepped portion around the bottom surface of the main body 30, on which the anti-corrosion preventing groove 35 of the electrode tip 3 is formed, can be inserted and fixed. It is preferably formed. As such, when the electrode tip 3 is disposed on the spot welding electrode 71, the spot welding protrusion 33 faces upward. As described above, the center electrode 4 is disposed on the upper portion of the electrode tip 3 disposed on the spot welding electrode 71 so that the bottom surface is in contact with the spot welding container of the electrode tip 3. And the center electrode 4 are energized to soften and melt the contact portion between the bottom surface of the center electrode 4 and the welding protrusion of the electrode tip 3 by the heat of resistance. Due to the nature of spot welding, if the cross-sectional area where the spot welding protrusion 33 and the center electrode 4 contact each other is small, the resistance at the time of energization increases and the amount of heat generated increases, so that the junction between the spot welding protrusion 33 and the center electrode 4 is easily formed. Since it can be welded, it is advantageous for spot welding. When the contact portion is melted, the energization area is enlarged to decrease the current density. Accordingly, the calorific value decreases, and a cooling action occurs naturally to solidify the welded portion. As a result, the bottom face of the spot welding protrusion 33 and the center electrode 4 is illustrated. As indicated by dots in 13b, they are formed by a nugget and a corona pond and joined together.

In order to increase the pressing force between the center electrode 4 and the electrode tip 3 during the primary welding as described above, the electrode tip 3 is fixed so that the electrode tip 3 receives a force toward the center electrode 4. A pressure spring 75 is preferably installed below the spot welding electrode 71 as shown in FIG. 14A.

Next, in order to perform laser welding, the center electrode 4 to which the electrode tip 3 is bonded is detached from the spot welder 7 as shown in FIG. 13B so that the laser beam LB (see FIG. 13C) becomes the electrode tip. It is arrange | positioned at the electrode fixing jig 91 of the laser welding machine 9 so that it may radiate to one side of the welding bar 31 of (3). In order to improve the weldability and shorten the welding time, it is preferable that the laser beam LB is radiated to both sides of the weld 31 as shown in FIG. 13C. When the center electrode 4 is disposed and the laser beam LB is radiated to the weld 31, the weld 31 is melted and the center electrode 4 and the electrode tip 3 are shown in FIG. 13D. Since the center welding portion and the edge portion, which are the joint portions of, are diffused and enlarged, the bonding strength is strengthened than in the first spot welding.

In this laser welding, the weld beam 31 is rotated around the weld 31 as shown in FIG. 13C so that the circumference of the weld 31 is evenly melted and rapidly melted so that welding can be performed well. ) Or the center electrode 4 is rotated by rotating the electrode fixing jig 91 as shown in FIG. 14B.

In addition, the pressing spring 95 is installed in the lower portion of the electrode fixing jig 91 which fixes the electrode tip 3 so that the electrode tip 3 receives a force toward the center electrode 4 when the laser beam LB is radiated. It is preferable.

As described above, not only the welding is performed quickly by the pressing portion of the electrode tip 3 and the center electrode 4 but also the weldability is excellent. That is, as shown by dots in FIGS. 13D and 13C, the central welding portion and the edge portion, which are the junction portions of the center electrode 4 and the electrode tip 3, are further diffused and enlarged, and thus the center electrode 4 and the electrode tip 3 are increased. ), So that the electrode tip 3 does not peel off from the center electrode 4.

The method of bonding the electrode tip 3 to the ground electrode 5 is also the same as described above, and the center electrode 4 and the ground electrode 5 to which the electrode tip 3 is bonded are assembled. The spark plug 1 as shown in 15 is completed.

Reference numeral 2 denotes a housing of the spark plug 1.

According to the electrode tip according to the present invention configured as described above, the anti-flame preventing groove 35 of various structures that can reduce the anti-inflammatory action when the electric flame occurs on the bottom surface of the main body 30 of the electrode tip 3 is formed When the electrode tip 3 ignites the spark plug 1 formed by joining the electrodes 4 and 5 of the spark plug 1, an electric flame is generated by the discharge between the electrode tips 3 and 3, respectively. Flame is introduced into the anti-flame prevention grooves 35 and 35 of both electrode tips 3 and 3, so that the size of the flame nucleus, that is, the electric flame, is easily ignited to improve the engine performance.

In addition, as the mixer is easily ignited, the voltage supplied to the ignition coil may be low. Therefore, the durability of the ignition device can be prevented by damaging the electrical system such as the ignition coil, distributor, or ignition cable that constitutes the ignition device by high voltage. Can improve.

Then, the welding tip 31 is formed around the electrode tip 3, and the spot welding protrusion 33 protrudes from the joining surface of the electrode tip 3, thereby providing the electrode tip 3 with respect to the electrode 4 or 5. Weldability is improved.

In addition, in the present invention, when the electrode tip 3 is bonded to the electrode 4 or 5, spot welding is performed first to form a center welding portion and an edge portion at the junction of the electrode tip 3 and the electrode 4 or 5. Next, a method of joining the electrode tip 3 to the electrodes 4 or 5 of the spark plug 1 by melting and distributing the welding teeth 31 by secondary laser welding to diffuse and increase the center welding portion and the edge portion. By adopting this, the electrode tip 3 is firmly bonded to the electrode 4 or 5 and is not peeled off, thus improving the durability of the electrode 4 or 5.

In addition, if the laser welding is performed after the first spot welding, the welding can be performed quickly and quickly, and the welding quality is also improved.

Claims (5)

An electrode tip for a spark plug bonded to the center electrode or the ground electrode of the spark plug, A main body; A weld rod formed around the upper half of the main body; A spot welding protrusion formed at the center of the upper surface of the main body; And, Anti-corrosion groove formed on the bottom of the main body in any one form selected from the group comprising a cross-shaped, circular and V-shaped cross section having a V-shaped cross section Spark tip electrode tip characterized in that it comprises a. In the group comprising a main body, a weld formed around the upper half of the main body, a spot welding protrusion formed at the center of the upper surface of the main body, and a lattice having a cross-shaped, circular and V-shaped cross section having a V-shaped cross section. As a method for bonding the electrode tip comprising an anti-inflammatory groove formed on the bottom surface of the main body in any one selected form to the electrode of the spark plug, The spot welding electrode is fixed on the upper surface of the spot welding electrode so that the spot welding protrusion faces upward, and the electrode is placed so that the bottom contacted with the spot welding protrusion. A first spot welding step of joining each other; The electrode having the electrode tip bonded by the primary spot welding is separated from the spot welding machine, placed in a laser welding machine, and a laser beam is radiated onto the welding rod of the electrode tip to melt the welding rod, thereby forming a center of the junction between the electrode and the electrode tip. A method of joining an electrode tip to an electrode of a spark plug, the method comprising a laser beam welding step of increasing a nugget and a corona pond. The method of claim 2, wherein, during the first spot welding, the electrode tip is pressed toward the electrode by a pressure spring installed under the spot welding electrode. The electrode fixing jig according to claim 2 or 3, wherein, during the laser welding, the laser beam is radiated to one side or both sides of the welding bar, and the laser beam radiating part rotates around the welding bar or fixes the electrode during the laser beam irradiation. How to bond the electrode tip to the electrode of the spark plug, characterized in that the rotation. The method of claim 4, wherein, during the laser welding, the electrode tip is pressed toward the center electrode by a pressing spring installed under the electrode fixing jig of the laser welder.