Ignition device having an electrode with a platinum firing tip and method of construction
Abstract
IGNITION DEVICE FOR AN INTERNAL COMBUSTION ENGINE, ELECTRODE ASSEMBLY FOR AN IGNITION DEVICE, AND METHOD FOR BUILDING AN IGNITION DEVICE. An igniter for an internal combustion engine and construction method, therefore, includes a housing with an insulator attached to it. A central electrode is mounted inside the insulator. A ground electrode extends from the housing with a portion of the ground electrode defining a spark gap through the central electrode. At least one of the center electrode or the selected ground electrode has a platinum or platinum based alloy tip. A resistance solder joint connects the trigger tip to the selected electrode and defines a bottom surface of the trigger tip that is embedded for a first distance below an external surface of the selected electrode. A continuous bead of overlapping laser weld pools is formed on an outer periphery of the firing tip. The overlapping weld pools extend a second distance below the outer surface of the selected electrode, with the second distance being greater than the first distance.

Term
1.3 yearsleft in the term
Expires 11 January 2028.
- Priority
- Filed
- Granted
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34 claims: 4 independent, 30 dependent
- 1REIVINDICAÇÕES 1. Dispositivo de ignição para um motor de combustão interna, caracterizado pelo fato de compreender:um alojamento tendo uma abertura;um isolante preso dentro do alojamento com uma extremidade do isolante exposta através da mencionada abertura no alojamento;um eletrodo central montado dentro do isolante e tendo uma extremidade livre se estendendo além do isolante;um eletrodo terra se estendendo a partir do alojamento com uma porção do eletrodo terra localizada oposta à extremidade livre do eletrodo central para definir um vão de centelha entre os mesmos;pelo menos um dentre o mencionado eletrodo central ou eletrodo terra selecionado tendo uma ponta de disparo baseada em platina;uma junta de solda por resistência ligando a mencionada ponta de disparo ao mencionado eletrodo selecionado, a mencionada junta de solda por resistência definindo uma superfície inferior da mencionada ponta de disparo embutida a uma primeira distância abaixo de uma superfície externa do mencionado eletrodo selecionado;e um cordão contínuo de poças de solda a laser sobrepostas formado sobre uma periferia externa da mencionada ponta de disparo ligando adicionalmente a mencionada ponta de disparo ao mencionado eletrodo selecionado, as mencionadas poças de solda sobrepostas se estendendo por uma segunda distância abaixo da mencionada superfície externa do mencionado eletrodo selecionado, onde a mencionada segunda distância é maior que a mencionada primeira distância.
- 2Dispositivo de ignição de acordo com a reivindicação 1, caracterizado pelo fato de que a mencionada ponta de disparo fica livre de rebaixos a partir das mencionadas poças de solda a laser.
- 3Dispositivo de ignição de acordo com a reivindicação 2, caracterizado pelo fato de que o mencionado eletrodo selecionado fica livre de rebaixos a partir das mencionadas poças de solda a laser.
- 4Dispositivo de ignição de acordo com a reivindicação 2, caracterizado pelo fato de que as mencionadas poças de solda a laser têm uma
- 55 parede lateral ligada à mencionada ponta de disparo, a mencionada ponta de disparo tendo um eixo central onde a mencionada parede lateral se estende radialmente extemamente a partir do mencionado eixo. 5. Dispositivo de ignição de acordo com a reivindicação 1, caracterizado pelo fato de que o mencionado eletrodo central tem uma 10 superfície lateral se estendendo ao longo de um eixo longitudinal e as mencionadas poças de solda a laser confinam com a mencionada superfície lateral.
- 6Dispositivo de ignição de acordo com a reivindicação 5, caracterizado pelo fato de que as mencionadas poças de solda a laser definem 15 uma superfície que é oblíqua à mencionada lateral.
- 7Dispositivo de ignição de acordo com a reivindicação 5, caracterizado pelo fato de que as mencionadas poças de solda a laser definem uma superfície geralmente cônica.
- 8Dispositivo de ignição de acordo com a reivindicação 1, 20 caracterizado pelo fato de que a mencionada superfície inferior da mencionada ponta de disparo é geralmente convexa.
- 9Dispositivo de ignição de acordo com a reivindicação 1, caracterizado pelo fato de que o mencionado eletrodo central tem uma parede lateral se estendendo ao longo de um eixo longitudinal e as mencionadas 25 poças de solda a laser são formadas radialmente intemamente a partir da mencionada parede lateral e fora de confinamento com a mencionada lateral.
- 10Dispositivo de ignição de acordo com a reivindicação 9, caracterizado pelo fato de que o mencionado eletrodo central tem uma superfície geralmente anular livre das mencionadas poças de solda a laser se estendendo a partir das mencionadas poças de solda a laser para a mencionada lateral.
- 11Dispositivo de ignição de acordo com a reivindicação 10, caracterizado pelo fato de que a mencionada superfície anular é formada em uma forma cônica.
- 12Conjunto de eletrodo para um dispositivo de ignição, caracterizado pelo fato de compreender:um corpo de eletrodo tendo uma superfície externa;uma ponta de disparo tendo uma superfície inferior e uma periferia externa;uma junta de solda por resistência ligando a mencionada superfície inferior de ponta de disparo ao mencionado corpo de eletrodo, a mencionada superfície inferior sendo embutida por uma primeira distância abaixo da mencionada superfície externa;e um cordão contínuo de poças de solda a laser sobrepostas formado sobre a mencionada periferia externa de ponta de disparo, as mencionadas poças de solda a laser se estendendo por uma segunda distância abaixo da mencionada superfície externa de corpo de eletrodo, a mencionada segunda distância sendo maior que a mencionada primeira distância.
- 13Conjunto de eletrodo de acordo com a reivindicação 12, caracterizado pelo fato de que o mencionado conjunto de eletrodo é um eletrodo central.
- 14Conjunto de eletrodo de acordo com a reivindicação 13, caracterizado pelo fato de que as mencionadas poças de solda a laser definem uma superfície cônica se estendendo radialmente extemamente a partir da mencionada ponta de disparo.
- 15Conjunto de eletrodo de acordo com a reivindicação 14, caracterizado pelo fato de que a mencionada superfície cônica se estende para uma parede lateral do mencionado corpo de eletrodo.
- 16Conjunto de eletrodo de acordo com a reivindicação 13, caracterizado pelo fato de que o mencionado corpo de eletrodo tem uma parede lateral e as mencionadas poças de solda a laser são espaçadas radialmente intemamente a partir da mencionada parede lateral.
- 17Conjunto de eletrodo de acordo com a reivindicação 16, caracterizado pelo fato de que uma superfície cônica se estende radialmente extemamente a partir das mencionadas poças de solda a laser adjacentes para a mencionada parede lateral.
- 18Conjunto de eletrodo de acordo com a reivindicação 12, caracterizado pelo fato de que a mencionada ponta de disparo fica livre de rebaixos a partir das mencionadas poças de solda a laser.
- 19Conjunto de eletrodo de acordo com a reivindicação 18, caracterizado pelo fato de que a mencionada ponta de disparo tem um eixo central e as mencionadas poças de solda a laser têm uma parede lateral anular ligada à mencionada ponta de disparo, a mencionada parede lateral se estendendo radialmente extemamente a partir do mencionado eixo central.
- 20Conjunto de eletrodo de acordo com a reivindicação 12, caracterizado pelo fato de que a mencionada ponta de disparo é baseada em platina.
- 21Método para construir um dispositivo de ignição, caracterizado pelo fato de compreender:prover um corpo de eletrodo tendo uma superfície externa;prover uma peça pré-formada de material de ponta de disparo de metal nobre;soldar por resistência o mencionado material de ponta de disparo ao mencionado corpo para, pelo menos parcialmente, formar uma ponta de disparo e definir uma superfície inferior da mencionada ponta de disparo a uma primeira distância abaixo da mencionada superfície externa;e soldar a laser um cordão contínuo de poças de solda a laser sobrepostas sobre uma periferia externa da mencionada ponta de disparo, de modo que as mencionadas poças de solda se estendam por uma segunda distância abaixo da mencionada superfície externa, onde a mencionada segunda distância é maior que a mencionada primeira distância. 5
- 22Método de acordo com a reivindicação 21, caracterizado pelo fato de incluir adicionalmente construir o mencionado dispositivo de ignição como um eletrodo central para uma vela de ignição.
- 23Método de acordo com a reivindicação 22, caracterizado pelo fato de incluir adicionalmente formar uma superfície cônica se 10 estendendo radialmente extemamente a partir da mencionada ponta de disparo via as mencionadas poças de solda a laser.
- 24Método de acordo com a reivindicação 23, caracterizado pelo fato de incluir adicionalmente formar a mencionada superfície cônica de modo que ela se estenda radialmente extemamente a partir da mencionada 15 ponta de disparo para uma parede lateral do mencionado corpo de eletrodo.
- 25Método de acordo com a reivindicação 22, caracterizado pelo fato de incluir adicionalmente formar as mencionadas poças de solda a laser de modo que elas fiquem espaçadas radialmente intemamente a partir de uma parede lateral do mencionado corpo de eletrodo por uma porção anular 20 não-soldada do mencionado corpo de eletrodo.
- 26Método de acordo com a reivindicação 25, caracterizado pelo fato de incluir adicionalmente formar uma superfície cônica sobre a mencionada porção anular não-soldada.
- 27Método de acordo com a reivindicação 21, caracterizado 25 pelo fato de incluir adicionalmente formar a mencionada ponta de disparo para ficar livre de rebaixos a partir das mencionadas poças de solda a laser.
- 28Método de acordo com a reivindicação 21, caracterizado pelo fato de incluir adicionalmente definir a mencionada superfície inferior tendo uma forma convexa.
- 29Método para construir um dispositivo de ignição para um motor de combustão interna, caracterizado pelo fato de compreender:prover um alojamento;prender um isolante dentro do alojamento com uma extremidade do isolante exposta através de uma abertura no alojamento;montar um corpo de eletrodo central tendo uma superfície externa dentro do isolante com uma região de ponta de disparo do corpo de eletrodo central se estendendo além do isolante;estender um corpo de eletrodo terra tendo uma superfície externa a partir do alojamento com uma região de ponta de disparo do corpo de eletrodo terra localizando-se oposta à região de ponta de disparo do corpo de eletrodo central para definir um vão de centelha entre os mesmos;prover pelo menos uma peça pré-formada do material de ponta de disparo formado a partir de metal nobre;soldar por resistência a mencionada pelo menos uma peça do material de ponta de disparo ao pelo menos um dentre o mencionado corpo de eletrodo central ou o mencionado corpo de eletrodo terra para, pelo menos parcialmente, formar uma ponta de disparo e definir uma superfície inferior da mencionada ponta de disparo a uma primeira distância abaixo da mencionada superfície externa;e soldar a laser um cordão contínuo de poças de solda a laser sobrepostas sobre uma periferia externa da mencionada ponta de disparo, de modo que as mencionadas poças de solda se estendam por uma segunda distância abaixo da mencionada superfície externa, onde a mencionada segunda distância é maior que a mencionada primeira distância.
- 30Método de acordo com a reivindicação 29, caracterizado pelo fato do mencionado material de ponta de disparo ser soldado ao mencionado corpo de eletrodo central e incluir adicionalmente formar uma superfície cônica se estendendo radialmente extemamente a partir da mencionada ponta de disparo via as mencionadas poças de solda a laser.
- 31Método de acordo com a reivindicação 30, caracterizado pelo fato de incluir adicionalmente formar a mencionada superfície cônica de modo que ela se estenda radialmente extemamente a partir da mencionada 5 ponta de disparo para uma parede lateral do mencionado corpo de eletrodo central.
- 32Método de acordo com a reivindicação 29, caracterizado pelo fato do mencionado material de ponta de disparo ser soldado ao mencionado corpo de eletrodo central e incluir adicionalmente formar as 10 mencionadas poças de solda a laser de modo que elas fiquem espaçadas radialmente intemamente a partir de uma parede lateral do mencionado corpo de eletrodo por uma porção anular não-soldada do mencionado corpo de eletrodo.
- 33Método de acordo com a reivindicação 32, caracterizado 15 pelo fato de incluir adicionalmente formar uma superfície cônica sobre a mencionada porção anular não-soldada.
- 34Método de acordo com a reivindicação 29, caracterizado pelo fato de incluir adicionalmente formar a mencionada ponta de disparo para ficar livre de rebaixos a partir das mencionadas poças de solda a laser. 20 35. Método de acordo com a reivindicação 29, caracterizado pelo fato de incluir adicionalmente definir a mencionada superfície inferior tendo uma forma convexa. 1/4 FIG - 2 FIG-3 2/4 FIG -7 3/4 FIG - 8 FIG - 9 FIG -10 FIG -11 4/4 FIG -14
Independent claims34
51 paragraphs in 8 sections, as filed
(54) Title: IGNITION DEVICE FOR AN INTERNAL COMBUSTION ENGINE, ELECTRODE ASSEMBLY FOR AN IGNITION DEVICE, AND METHOD FOR BUILDING AN IGNITION DEVICE (30) Unionist Priority: 18/01 / 2007US 11/624272 (73) Owner (s): Federal-Mogul Ignition Company (72) Inventor (s): Paul Tinweii (74) Attorney (s): Momsen, Leonardos & CIA.
(86) International Order: pct us2008050827 of 11/01/2008 (87) International Publication: wo 2008 / 089048of 24/07/2008 (57) Summary: igniter for an INTERNAL COMBUSTION engine, ELECTRODE ASSEMBLY FOR A DEVICE OF IGNITION, AND, METHOD FOR BUILDING AN IGNITION DEVICE. An igniter for an internal combustion engine and construction method, therefore, includes a housing with an insulator attached to it. A central electrode is mounted inside the insulator. A ground electrode extends from the housing with a portion of the ground electrode defining a spark gap through the central electrode. At least one of the center electrode or the selected ground electrode has a platinum or platinum based alloy tip. A resistance solder joint connects the trigger tip to the selected electrode and defines a bottom surface of the trigger tip that is embedded for a first distance below an external surface of the selected electrode. A continuous bead of overlapping laser weld pools is formed on an outer periphery of the firing tip. The overlapping weld pools extend a second distance below the outer surface of the selected electrode, with the second distance being greater than the first distance.
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“IGNITION DEVICE FOR A COMBUSTION ENGINE
INDOOR, ELECTRODE ASSEMBLY FOR A DEVICE OF
IGNITION, AND, METHOD FOR BUILDING A DEVICE OF
IGNITION"
BACKGROUND OF THE INVENTION
1. Technical field
This invention generally relates to spark plugs and other ignition devices and, more particularly, to electrodes having platinum trigger tips and a method of constructing them.
2. Correlated technique
Within the field of spark plugs, there is a continuing need to improve resistance to erosion and reduce the collapse voltage between the center of the spark plug and the ground electrodes. Several designs have been proposed using noble metal electrodes or, more commonly, noble metal firing tips applied to standard metal electrodes. Typically, the firing tip is formed as a pad or rivet which is then welded over the electrode end.
In the construction of noble metal firing tips, there is also a continuing need to improve the reliability of coupling the noble metal firing tip material to the electrode material, which is often constructed from a nickel alloy. For example, in US patent 6,132,277, awarded to the present assignee, a precious metal is placed on a planar surface of the electrode, welded by resistance, then welded by resistance thereto. In addition, the desired shape of the precious metal firing tip is preferably formed after resistance welding, and can then be resistance welded again to further secure the firing tip to the electrode that may have been loosened during the forming process or may not have been firmly coupled during initial resistance welding.
US patent 5,811,915 discloses another construction of a spark plug having a precious metal chip attached to an electrode. The '915 patent teaches how to attach a noble metal chip formed from iridium, or an alloy of it, first, by resistance welding the chip to the electrode.
During the resistance welding process, the noble metal chip remains non-molten and is pushed towards the electrode, so that it plunges into the molten electrode material, thereby forming protruding portions around an outer perimeter the chip. Subsequently, a laser beam is applied to a point location, shown as two points generally opposite each other, on the protruding portion of the electrode at an incident angle of 45 degrees to fuse the collided protruding portion of the electrode and a lateral surface of the chip of noble metal in the vicinity of the protruding portion. Consequently, a laser weld joint extends into a side surface of the precious metal chip above its lower surface, which was previously dipped into the molten electrode material. Then, another peripheral laser weld is carried out entirely along the outer periphery of the noble metal chip, by rotating the electrode around its axis.
In US patent 6,705,009, another construction of a spark plug having a precious metal attached to a central electrode is disclosed. The '009 patent teaches how to couple a flat end of a continuous precious metal wire to a flat end of a tapered ignition tip of the central electrode via a first resistance or friction weld. During the first weld, the end of the wire forms a flat top weld joint with the end of the central electrode. The wire is then cut, and a second weld is formed via a laser around the outer periphery of the first weld joint between the cut wire and the central electrode.
US patent 6,819,031 discloses another construction of a spark plug having a precious metal firing tip attached to an electrode. The '031 patent teaches how to couple a noble metal chip to a central electrode via a resistance weld or a temporary template and then form a laser weld around a complete circumference of the noble metal chip and electrode interface center to form a first weld layer. The laser is then moved along the longitudinal axis of the central electrode to form a second weld around the complete circumference of the interface, with additional weld layers being possible thereafter, as each additional weld layer is moved axially along the axis. longitudinal direction of the electrode.
In US patent 6,827,620, another construction of a spark plug having a precious metal attached to an electrode is disclosed. The '620 patent teaches how to couple a noble metal chip to a central electrode via a temporary resistance weld and, after that, form a final laser weld. The noble metal chip is a column-shaped element of iridium, or an iridium alloy material. During temporary resistance welding, the chip is pressed with sufficient force to insert a non-fused column-shaped portion into the electrode, preferably by no more than 0.1 mm.
Of all known electrode constructions having a precious metal firing tip, including those examined here, each comes with potential disadvantages. Some of the possible disadvantages include increased manufacturing costs, a limited number of types of tip materials available for use, or a combination thereof. Thus, the objective of the invention seeks to remedy these and other potential problems present in known constructions.
SUMMARY OF THE INVENTION
An igniter for an internal combustion engine constructed in accordance with the invention includes a housing having an opening and an insulator trapped within the housing. The insulator has an exposed end through the opening in the housing. A central electrode is mounted inside the insulator and has a free end extending beyond the insulator. A ground electrode extends from the housing with a portion of the ground electrode located opposite the free end of the central electrode to define a spark gap between them. At least one of the central electrode or the ground electrode has a platinum or platinum based alloy tip. A resistance solder joint connects the trigger tip to the selected electrode, where the resistance solder joint defines a bottom surface of the trigger tip that is embedded at a first distance below an external surface of the selected electrode. A continuous strand of overlapping laser weld pools is formed on an outer periphery of the trigger tip to further connect the trigger tip to the selected electrode. The overlapping weld pools extend a second distance below the outer surface of the selected electrode, so that the second distance is greater than the first distance.
Another aspect of the invention includes an electrode assembly for an igniter. The electrode assembly has an electrode body with an outer surface and a trigger tip with a bottom surface and an outer periphery. A resistance weld joint connects the bottom surface of the firing tip to the electrode body, so that the bottom surface is embedded at a first distance below the outer surface. A continuous bead of overlapping laser weld pools is formed on the outer periphery of the trigger tip, with the laser weld pools extending a second distance below the outer surface of the electrode body with the second distance being greater than the first distance.
Yet another aspect of the invention includes a method for building an igniter for an internal combustion engine. The method includes providing a housing and securing an insulator within the housing, so that one end of the insulator is exposed through an opening in the housing. Then, mount a central electrode body having an external surface inside the insulator with a trigger tip region of the central electrode body extending beyond the insulator. Then, extend an earth electrode body having an outer surface from the housing with a trigger tip region of the earth electrode body located opposite the trigger tip region of the central electrode body to define a spark gap between them . In addition, provide at least one pre-formed piece of the firing tip material made of noble metal. In addition, resistance welding of at least one piece of firing tip material to at least one of the central electrode body or the ground electrode body to form, at least partially, a firing tip, with the weld joint by resistance defining a lower surface of the firing tip that is at a first distance below the outer surface. Then, laser weld a continuous bead of laser weld pools superimposed on an outer periphery of the firing tip with the weld puddles extending a second distance below the outer surface, where the second distance is greater than the first distance.
Another aspect of the invention includes a method for building an igniter. The method includes providing an electrode body having an outer surface and a preformed piece of noble metal firing tip material. Then, resistance-weld the trigger tip material to the body to at least partially form a trigger tip and define a lower surface of the trigger tip at a first distance below the outer surface. In addition, laser welding a continuous bead of laser weld pools superimposed on an outer periphery of the firing tip, so that the weld pools extend a second distance below the outer surface, where the second distance is greater than the first distance.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features and advantages of the present invention will be more readily appreciated when considered in connection with the following detailed description of the presently preferred embodiments and best mode and the accompanying drawings, where, with similar characteristics, reference numbers have been given. similar, and where:
fig. 1 is a partial side view of a spark plug having a central electrode and an earth electrode constructed in accordance with a presently preferred embodiment of the invention;
fig. 2 is an enlarged partial side view of an initial step in the construction of the electrode according to a presently preferred embodiment of the invention;
fig. 3 is a side view in enlarged partial cross section of the ground electrode after conducting a resistance welding process;
fig. 4 is a side view in enlarged partial cross-section of the ground electrode after carrying out a forming process;
fig. 5 is an enlarged partial side view of the ground electrode showing the orientation of a laser beam during a laser welding process;
fig. 6 is a side view in enlarged partial cross section of the ground electrode after the laser welding process has been carried out;
fig. 7 is an enlarged partial top view of the ground electrode shown in the finished state;
fig. 8 is an enlarged partial side view of an initial stage of construction of the central electrode according to a presently preferred embodiment of the invention;
fig. 9 is a side view in enlarged partial cross-section of the central electrode after performing a resistance welding process;
fig. 10 is a side view in enlarged partial cross-section of the central electrode showing the orientation of a laser beam during a laser welding process;
fig. 11 is a side view in enlarged partial cross-section of the central electrode after performing the laser welding process;
fig. 12 is a side view in enlarged cross-section of the central electrode in a finished state after the completion of a forming process;
fig. 13 is an enlarged partial side view of the central electrode showing the orientation of a laser beam during a laser welding process according to another embodiment of the invention; and fig. 14 is a side view in enlarged cross section of the central electrode in a finished state when the laser welding process of fig. 13.
DETAILED DESCRIPTION OF PERFORMANCE MODES
PREFERRED
With more detailed reference to the drawings, figure 1 shows a firing end of a spark plug 10 constructed in accordance with the presently preferred method of construction of the invention. The spark plug 10 includes a metal case or housing 12, an insulator 14 stuck inside the housing 12, a central electrode 16, a ground electrode 18, and a pair of trigger tips 20, 22 located opposite each other on the central and ground electrodes 16, 18, respectively. The housing 12 can be constructed in a conventional manner like a metal shell and can include normal threads 24 and an annular lower end 26 from which the earth electrode 18 extends, as if it is welded or otherwise joined thereto. Similarly, all other components of the spark plug 10 (including those not shown) can be constructed using known techniques and materials, with the exception of central and / or ground electrodes 16, 18 which have trigger points 20, 22 constructed from according to the present invention.
As is known, the annular end 26 of the housing 12 defines an opening 28 through which the insulator 14 preferably extends. The central electrode 16 is generally mounted inside the insulator 14 by a glass seal or using another suitable technique. The central electrode 16 can have any suitable shape, but it is usually generally cylindrical, having a widening or tapering arc to a larger diameter on the end opposite the trigger tip 20 to facilitate seating and sealing the end inside the insulator 14. The central electrode 16 generally extends out of the insulator 14 through an exposed axial end 30. The central electrode 16 is constructed from any suitable conductor, as is well known in the field of spark plug manufacturing, such as various NI alloys and Ni-based, for example, and may also include such materials overlaid on an alloy core. Cu or Cu-based.
The ground electrode 18 is illustrated, as an example and without limitations, in the form of a conventional elbow arched by 90 degrees in a generally rectangular cross section. The ground electrode 18 is coupled to the housing 12 by an end 32 for electrical and thermal communication with it, and preferably ends at a free end 34 generally opposite the central electrode 16. A firing portion or end is defined adjacent to the free end 34 of the ground electrode 18 which, together with the corresponding firing end of the central electrode 16, defines a spark gap 36 between them.
However, it will be readily understood by someone skilled in the art that the ground electrode 18 can have a multitude of configurations, shapes and sizes.
The firing tips 20, 22 are each located at the firing ends of their respective electrodes 16, 18, in order to provide sparking surfaces 21, 23, respectively, for the emission and reception of electrons through the spark gap 36. As seen from the trigger tip surfaces 21, 23, as shown for surface 23 in Figure 7, which also applies to the trigger tip surface 21, it can be seen that the trigger tip surfaces 21, 23 have a generally circular geometric shape, which is defined, at least partially, by the construction method explained below. The firing tips 20, 22 comprise noble metals that are relatively soft and have a lower melting point than a known and widely used noble metal, iridium (Ir), which has a melting temperature of about 2,447 ° C. The preferred noble metal used here is platinum (Pt), which has a melting temperature of about 1,769 ° C, or an alloy thereof, such as platinum-nickel (Pt-Ni), for example, which has a higher melting temperature low.
According to the invention, the firing tips 20, 22 are first welded to the resistance on their respective electrodes 16, 18 and then they are laser welded for greater grip of their coupling to the electrodes and to prevent unwanted ingress of oxidation in the welded joint formed between firing tips 20, 22 and electrodes 16, 18. The resistance welded joint defines a bottom surface 40 embedded at a first distance (d) under an external surface 42 of the respective electrode 16, 18. The laser welded joint defines overlapping weld pools 44 that extend a second distance (D ) under the outer surface 42 of the respective electrode 16, 18, where the second distance (D) is greater than the first distance (d). To assist in the establishment of a reliable welded joint, and to further assist in inhibiting the ingress of oxidation, the laser welded joint is formed so that the respective firing tip 20, 22 is free from recesses in laser weld pools 44 . Consequently, each of the laser weld pools 4 forms a side wall 46 which is firmly attached to the respective firing tip 20, 22, where the side wall 46 is generally parallel and / or radially extending off a central axis 48 of the firing tip 20, 22 when extending below the outer surface 42.
In the construction of the respective electrode 16, 18, as shown in figure 2, a preformed PT pad 50, represented here as having preferably an arcuate, convex or spherical surface 52 and, more preferably, as being generally spherical or in the form of a sphere, it is placed on its outer surface 42. The pad 50 is then welded to the resistance to electrode 16, 18. During the resistance welding process, with the spherical surface 52 of the pad 50 being convex, any presence of oxide 54 formed on the outer surface 42 is caused to be evacuated during the resistance welding process, as generally indicated by the arrows 56. Consequently, when the generally spherical surface 52 of pad 50 is pushed under a weld shaft (not shown) to the outer surface 42 of electrode 16, 18, oxide 54 is pushed out of the welded joint. Additionally, the generally convex shape has a minimum contact area, theoretically established as a point between the pad 50 and the electrode 16, 18 which, in turn, increases the electrical resistance between the pad 50 and the respective electrode 16, 18 during the resistance welding process and thus increasing the heat generated during the resistance welding process. This facilitates the formation of a welded joint to the reliable resistance by providing a good union between melting materials of the non-similar materials being joined.
By forming a suitable weld puddle of both materials, and pressing pad 50 to the desired depth (d) below the outer surface, 42 of electrode 16, 18, the applied electrical current is turned off, and the weld puddle established it is allowed to solidify generally free of oxide inclusions.
Then, as shown in figure 3, a portion 58 of the pad 50 may require additional shaping to obtain the desired finished shape. In this way, the pad 50 can be coined or otherwise shaped so that the firing surface 21, 23 of the respective firing tip 20, 22 is generally flat and parallel to the outer surface 42 of electrode 16, 18, as shown in figure 4.
When forming the firing tip 20, 22, a laser welded joint 60 is established to enhance the mechanical resistance of the firing tip connection 20, 22 to the respective electrode 16, 18, such as, as an example and without limitations, a head GSI-Lumonics trepanation with pulsed ND-YAG laser. In a preferred embodiment, the laser welding energy was controlled between about 11.5J / pulse, the welding frequency between about 75-85Hz, and the optical focus diameter between about 0.20mm-0, 25mm to provide individual weld pools of about 0.50mm in diameter. To carry out laser welding, the laser head, and thus a laser beam 62, is drilled around the electrode 16, 18 and the respective trigger tip 20, 22, which are preferably kept stationary. The preferred speed for clamping the laser head is between about 140-160rpm, while the preferred nuance of pulse / spot welds is between about 30-33. It must be recognized that, depending on the determined application, the parameters mentioned above may be changed. During the laser welding process, it is also preferred that a cover gas is used, such as argon, for example, where the flow rate of the cover gas can be controlled as best suited for the application, such as about 5.661 / min, for example.
As shown in figure 5, the laser beam 62 is preferably held at about 90 orientation cranes with respect to the weld surface 42. In addition, the focal point of the laser beam is preferably kept as close to an outer periphery 64 of the firing pad as possible, and preferably over an exposed weld seam 66 between firing tip 20, 22 and the respective electrode body 16, 18, during the initial resistance welding process, thereby making that the continuous bead of overlapping weld pools 44 formed by the pulsed laser weld completely cover the seam 66, as shown in figure 7. As noted above, this increases the bond strength between the trigger tip material and the electrode material , while also inhibiting the entry of oxygen into the welded joint established between the trigger tip 20, 22 and the respective electrode 16, 18.
As shown in figure 6, the individual laser weld pools 44 extend below the outer surface 42 of electrode 16, 18 to the predetermined depth (D) which is greater than the depth (d) of the lower surface of the firing tip 40. Consequently, laser weld pools 44 extend below the resistance welded joint that was formed in the previous resistance welding process. With the orientation of the laser beam 62 being approximately 90 degrees in relation to the outer surface 42 of the electrode 16, 18, the laser weld pools 44 are formed so that they do not form a recess in the material defining the tip of the shot 20, 22. As shown in figure 6, the laser weld puddles 44 form a toroid or annular ring having a generally fustustonic shape in the axial cross section, where the inner side walls 46 of the individual laser weld puddles 44 join the respective firing tips 20, 22. The side wall 46 of the solidified continuous laser weld pool is generally parallel to and / or extends radially outward from the central axis 48 of the firing tip 20, 22.
As shown in figure 8, in another presently preferred construction, with particular reference to the central electrode 16, instead of using an initially spherical Pt pad, a PT 150 rivet having a generally frustoconical shape end 152 for coupling to the central electrode is used to form a trigger tip 120. As described above in association with the spherical or convex surface, the shape of the end 152 facilitates an increase in the resistance and expulsion of the oxide, as shown in figure 9 by the arrows 56, during an initial resistance welding process. Consequently, as in the previous embodiment, the rivet of Pt 150 is first welded to the resistance to the outer outer surface 42 of the central electrode 16. The Pt 150 rivet is preferably centered on the end, where an annular surface 70 of the end generally concentric to the longitudinal axis 48 of electrode 16 remains exposed and generally free from the effects of the resistance welding process. Then, as above, the PT 150 rivet is still attached to the central electrode 16 in a pulsed laser welding process. Since the central electrode 16 is typically cylindrical, the pulsed laser beam 62 can be trepaned as explained above, or the central electrode 16 can be rotated, and the laser beam 62 is kept in a fixed location. Laser weld pools 44 are formed in the same manner as described above, and are shown here as being formed radially spaced into a side wall 72 of central electrode 16. Thus, as shown in figure 11, an annular ring 74 generally free from the effects of the laser welding process remains at the end of the central electrode 16. Upon completing the laser welding process, the central electrode 16 can be considered finished for use . Otherwise, as shown in figure 12, the end of the central electrode 16 can be formed, as in a machining operation, to form a tapered or tapered wall 76 generally extending from the continuous laser weld pools 44 to the side wall 72. Preferably, the tapered wall 76 is formed adjacent to the laser weld pools 44, and slightly radially spaced out of it so as not to touch or extend into the laser weld pools 44.
In yet another still preferred construction of the central electrode 16, as shown in figures 13 and 14, instead of leaving an unaffected annular ring 74 between the side wall 72 of the electrode 16 and the laser weld pools 44, the laser weld it can be made so that the laser weld pools 44 extend radially outwardly in contact with the side wall 72, or substantially close to it. This can be done by increasing the energy of the laser beam, by changing the optical focus diameter of the laser beam 62, or both, thereby causing a larger area to be affected by the thermal energy of the laser beam pulses. . In doing so, the laser weld pools 44 preferably form a tapered or tapered surface 78 without the need for a secondary machining operation, as described in connection with figure 12.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is to be understood, therefore, that, within the scope of the appended claims, the invention may be practiced in a manner other than that specifically described.
Contents8
7 sheets
Sheet 1 Sheet 2 Sheet 3 Sheet 4 Sheet 5 Sheet 6 Sheet 7
21 members in 7 offices
Priority claims7
| Document | Office | Kind | Date |
|---|---|---|---|
| 11624272 | United States of America | – | |
| 62427207 | United States of America | A | |
| 2008050827 | United States of America | W | |
| 11624272 | – | – | – |
| 2008050827 | – | – | – |
| US20070624272 | – | – | – |
| WO2008US50827 | – | – | – |
Members21
| Document | Office | Kind | |
|---|---|---|---|
| US2008174221A1 | United States of America | A1 | |
| US2008174222A1 | United States of America | A1 | |
| WO2008089048A1 | World Intellectual Property Organization (WIPO) | A1 | |
| WO2009042557A2 | World Intellectual Property Organization (WIPO) | A2 | |
| WO2009042557A3 | World Intellectual Property Organization (WIPO) | A3 | |
| EP2109923A1 | European Patent Office (EPO) | A1 | |
| KR20090117741A | Republic of Korea | A | |
| CN101636888A | China | A | |
| JP2010517225A | Japan | A | |
| EP2193582A2 | European Patent Office (EPO) | A2 | |
| KR20100082786A | Republic of Korea | A | |
| CN101842948A | China | A | |
| JP2011501859A | Japan | A | |
| US7923909B2 | United States of America | B2 | |
| BRPI0806625A2This record | Brazil | A2 | |
| US8026654B2 | United States of America | B2 | |
| CN101842948B | China | B | |
| EP2109923A4 | European Patent Office (EPO) | A4 | |
| EP2193582A4 | European Patent Office (EPO) | A4 | |
| EP2109923B1 | European Patent Office (EPO) | B1 | |
| EP2193582B1 | European Patent Office (EPO) | B1 |
2 legal events, as the office reported them to INPADOC
Over the term
Point at a mark for the eventEvents
| Event | Code | |
|---|---|---|
| Patent lapsed as no evidence of payment of the annual fee has been furnished to inpi [chapter 8.11 patent gazette]LapsedREFERENTE AO DESPACHO 8.6 PUBLICADO NA RPI 2288 DE 11/11/2014.B08K | B08K | |
| Application dismissed because of non-payment of annual fees [chapter 8.6 patent gazette]REFERENTE A 7A ANUIDADE.B08F | B08F |
Numbers
- Publication
- PI0806625
- Publication, DOCDB
- PI0806625
- Publication, EPODOC
- BRPI0806625
- Application
- 6625
- Application, DOCDB
- PI0806625
- Application, EPODOC
- BR2008PI06625
Titles2
- Portuguese
- DISPOSITIVO DE IGNIÇÃO PARA UM MOTOR DE COMBUSTÃO INTERNA, CONJUNTO DE ELETRODO PARA UM DISPOSITIVO DE IGNIÇÃO, E, MÉTODO PARA CONSTRUIR UM DISPOSITIVO DE IGNIÇÃO
- English
- IGNITION DEVICE FOR AN INTERNAL COMBUSTION ENGINE, ELECTRODE ASSEMBLY FOR AN IGNITION DEVICE, AND METHOD FOR BUILDING AN IGNITION DEVICE
Classification
- CPC, 5
- H01T13/32
- H01T13/20
- H01T13/39
- H01T21/02
- H01T13/02
- IPC, 2
- H01T13 20
- H01T13 02