WO2017037969A1 - スパークプラグ - Google Patents
スパークプラグ Download PDFInfo
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- WO2017037969A1 WO2017037969A1 PCT/JP2016/002771 JP2016002771W WO2017037969A1 WO 2017037969 A1 WO2017037969 A1 WO 2017037969A1 JP 2016002771 W JP2016002771 W JP 2016002771W WO 2017037969 A1 WO2017037969 A1 WO 2017037969A1
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- discharge
- electrode
- spark plug
- base material
- layer
- Prior art date
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T13/00—Sparking plugs
- H01T13/20—Sparking plugs characterised by features of the electrodes or insulation
- H01T13/32—Sparking plugs characterised by features of the electrodes or insulation characterised by features of the earthed electrode
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T1/00—Details of spark gaps
- H01T1/20—Means for starting arc or facilitating ignition of spark gap
- H01T1/22—Means for starting arc or facilitating ignition of spark gap by the shape or the composition of the electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T1/00—Details of spark gaps
- H01T1/24—Selection of materials for electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T13/00—Sparking plugs
- H01T13/20—Sparking plugs characterised by features of the electrodes or insulation
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T13/00—Sparking plugs
- H01T13/20—Sparking plugs characterised by features of the electrodes or insulation
- H01T13/39—Selection of materials for electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01T—SPARK GAPS; OVERVOLTAGE ARRESTERS USING SPARK GAPS; SPARKING PLUGS; CORONA DEVICES; GENERATING IONS TO BE INTRODUCED INTO NON-ENCLOSED GASES
- H01T13/00—Sparking plugs
- H01T13/20—Sparking plugs characterised by features of the electrodes or insulation
- H01T13/38—Selection of materials for insulation
Definitions
- the present invention relates to a spark plug.
- the present invention has been made to solve the above-described problems, and can be realized as the following forms. *
- a central electrode extending in the axial direction; an insulator having an axial hole and the central electrode being provided in the axial hole; and a cylindrical metal shell holding the insulator
- An electrode base material having one end connected to the tip of the metal shell, and a discharge chip joined to the inner surface of the other end of the electrode base material and facing the center electrode with a gap therebetween
- a spark plug comprising a ground electrode.
- the discharge chip includes: a discharge layer including a noble metal or a noble metal alloy disposed on the center electrode side; one end joined to the discharge layer, and at least a part of the other end via the melting portion.
- the discharge chip When the discharge chip is viewed, it is formed at least in a region on the other end side of the electrode base material from the center of the discharge layer; includes a center line along the longitudinal direction of the ground electrode and is parallel to the axis.
- the ratio of the length along the longitudinal direction of the melted portion in the range where the discharge chip exists along the longitudinal direction to the length of the discharge chip along the longitudinal direction is It is 76.2% or more.
- the end face of the intermediate layer may be exposed on the other end side of the electrode base material.
- the discharge chip is compared with the case where the end surface of the intermediate layer is covered with the melted portion. It is possible to improve the wear resistance of the spark.
- the area of the surface of the discharge chip facing the center electrode may be 0.75 mm 2 or more. If it is a spark plug of such a form, durability of a spark plug can be improved.
- the ratio may be 100% or more. If it is a spark plug of such a form, it can suppress more that the discharge chip provided with a discharge layer and an intermediate
- the present invention can be implemented in various forms other than the above-described form as a spark plug, such as a spark plug manufacturing method.
- FIG. 1 It is a longitudinal cross-sectional view of the front-end
- FIG. It is a longitudinal cross-sectional view of the front-end
- FIG. 1 is a partial sectional view of a spark plug 100 in one embodiment of the present invention.
- the spark plug 100 has an elongated shape along the axis O.
- the right side of the axis O indicated by a dashed line shows an external front view
- the left side of the axis O shows a cross-sectional view passing through the axis O.
- the lower side in FIG. 1 is referred to as the front end side of the spark plug 100
- the upper side in FIG. 1 is referred to as the rear end side.
- the XYZ axes in FIG. 1 correspond to the XYZ axes in the other drawings.
- the axis O and the Z axis are parallel.
- the front end side of the spark plug 100 is the + Z direction
- the rear end side of the spark plug 100 is the ⁇ Z direction.
- the simple “Z direction” refers to a direction parallel to the Z axis (a direction along the Z axis). The same applies to the X axis and the Y axis. *
- the spark plug 100 includes an insulator 10, a center electrode 20, a ground electrode 30, and a metal shell 50.
- the insulator 10 has at least a part of its outer periphery held by a cylindrical metal shell 50 and has a shaft hole 12 along the axis O.
- a center electrode 20 is provided in the shaft hole 12.
- the ground electrode 30 is fixed to the front end surface 57 of the metal shell 50 and forms a discharge gap G between the ground electrode 30 and the center electrode 20.
- the insulator 10 is an insulator formed by firing a ceramic material such as alumina.
- the insulator 10 is a cylindrical member in which a part of the center electrode 20 is accommodated at the front end side and the shaft hole 12 that accommodates a part of the terminal fitting 40 is formed at the rear end side.
- a central body 19 having a larger outer diameter is formed at the center in the axial direction of the insulator 10.
- a rear end side body portion 18 that insulates between the terminal metal fitting 40 and the metal shell 50 is formed on the terminal metal fitting 40 side of the central body portion 19.
- a front end side body portion 17 having an outer diameter smaller than that of the rear end side body portion 18 is formed on the side of the center electrode 20 relative to the central body portion 19, and a front end side body portion 17 is further provided ahead of the front end side body portion 17.
- a leg length portion 13 having a smaller outer diameter and a smaller outer diameter toward the center electrode 20 side is formed.
- the metal shell 50 is a cylindrical metal fitting that surrounds and holds a portion extending from a part of the rear end body portion 18 of the insulator 10 to the long leg portion 13.
- the metal shell 50 is made of, for example, low carbon steel, and is subjected to a plating process such as nickel plating or zinc plating.
- the metal shell 50 includes a tool engaging portion 51, a seal portion 54, and a mounting screw portion 52 in order from the rear end side.
- the tool engaging portion 51 is fitted with a tool for attaching the spark plug 100 to the engine head.
- the attachment screw portion 52 has a thread that is screwed into the attachment screw hole of the engine head.
- the seal portion 54 is formed in a hook shape at the base of the mounting screw portion 52.
- An annular gasket 5 formed by bending a plate is fitted between the seal portion 54 and the engine head.
- the front end surface 57 of the metal shell 50 has a hollow circular shape, and the leg long portion 13 of the insulator 10 and the center electrode 20 protrude from the center thereof.
- a thin caulking portion 53 is provided on the rear end side of the metal shell 50 from the tool engaging portion 51. Further, between the seal portion 54 and the tool engaging portion 51, a compression deformation portion 58 having a small thickness is provided in the same manner as the caulking portion 53. Between the inner peripheral surface of the metal shell 50 from the tool engaging portion 51 to the crimping portion 53 and the outer peripheral surface of the rear end side body portion 18 of the insulator 10, annular ring members 6 and 7 are interposed. Further, talc (talc) 9 powder is filled between the ring members 6 and 7.
- the compression deformation portion 58 is compressed and deformed by pressing the crimping portion 53 inward so as to be bent inward, and the compression deformation of the compression deformation portion 58 causes the ring members 6, 7 and The insulator 10 is pressed toward the front end side in the metal shell 50 through the talc 9. By this pressing, the talc 9 is compressed in the direction of the axis O, and the airtightness in the metal shell 50 is enhanced.
- an insulator step portion located at the base end of the leg long portion 13 of the insulator 10 via an annular plate packing 8 on a metal inner step portion 56 formed at the position of the mounting screw portion 52. 15 is pressed.
- the plate packing 8 is a member that maintains airtightness between the metal shell 50 and the insulator 10, and prevents the combustion gas from flowing out.
- the center electrode 20 is a rod-like member in which a core material 22 having better thermal conductivity than the center electrode base material 21 is embedded in the center electrode base material 21.
- the center electrode base material 21 is made of a nickel alloy containing nickel as a main component
- the core member 22 is made of copper or an alloy containing copper as a main component.
- a flange portion 23 having a shape projecting to the outer peripheral side is formed in the vicinity of the rear end portion of the center electrode 20, a flange portion 23 having a shape projecting to the outer peripheral side is formed.
- the flange 23 contacts the shaft hole inner step 14 formed in the shaft hole 12 from the rear end side, and positions the center electrode 20 in the insulator 10.
- the rear end portion of the center electrode 20 is electrically connected to the terminal fitting 40 via the ceramic resistor 3 and the seal body 4.
- the ground electrode 30 is made of a metal having high corrosion resistance.
- a metal having high corrosion resistance for example, a nickel alloy mainly composed of nickel such as Inconel (trade name) 600 or Inconel 601 is used.
- the proximal end of the ground electrode 30 is welded to the distal end surface 57 of the metal shell 50.
- the ground electrode 30 is bent at an intermediate portion so that one side surface of the tip portion of the ground electrode 30 faces the center electrode 20.
- the ground electrode 30 includes a rectangular columnar discharge chip 80 that protrudes toward the center electrode 20 that is the other electrode on the inner side surface of the tip end (other end) 32 and forms a discharge gap G. 1 passes through the center P of the discharge chip 80.
- FIG. 2 is a longitudinal sectional view of the tip 32 of the ground electrode 30.
- 2 is a cross section including the center line C along the longitudinal direction of the ground electrode 30 and parallel to the axis O.
- the center line C of the ground electrode 30 is a line along the longitudinal direction of the ground electrode 30 that bisects the ground electrode 30 in the width direction.
- the middle portion of the ground electrode 30 is bent so as to face the center electrode 20, but the longitudinal direction of the ground electrode 30 is the Y direction.
- the width direction of the ground electrode 30 is parallel to the X-axis direction.
- the Y-axis direction is a direction perpendicular to the X-axis direction and the Z-axis direction, and is parallel to the longitudinal direction of the ground electrode 30.
- the ground electrode 30 includes an electrode base material 31, a discharge tip 80, and a melting portion 84.
- the discharge chip 80 is a clad material formed by bonding a discharge layer 82 and an intermediate layer 83.
- the surface 86 facing the center electrode 20 has a square column shape.
- the discharge chip 80 will be described with the + Y direction as the front end 85 and the ⁇ Y direction as the rear end 88. *
- the discharge layer 82 is disposed on the center electrode 20 side.
- the discharge layer 82 includes a noble metal or a noble metal alloy, and is formed of, for example, platinum (Pt), iridium (Ir), ruthenium (Ru), rhodium (Rh), or an alloy thereof.
- One end of the intermediate layer 83 is joined to the discharge layer 82, and at least a part of the other end is welded to the electrode base material 31.
- the other end of the intermediate layer 83 shown in FIG. 2 also includes a boundary portion 36 between the intermediate layer 83 and the electrode base material 31.
- the intermediate layer 83 includes a noble metal element contained most in the discharge layer 82 and an element contained in the electrode base material 31.
- the amount of the noble metal element contained in the intermediate layer 83 is less than that of the discharge layer 82 in mass percent.
- the intermediate layer 83 includes a small amount of Pt in a mass percentage ratio relative to the discharge layer 82, and the electrode base material 31.
- a Pt—Ni-based alloy containing nickel is used.
- Such a clad material composed of the discharge layer 82 and the intermediate layer 83 is formed, for example, by rolling the discharge layer 82 and the intermediate layer 83 while applying heat.
- the melting portion 84 is located near the boundary portion 36 between the intermediate layer 83 and the electrode base material 31.
- the melting portion 84 extends from the tip 85 side (+ Y direction) of the discharge chip 80 toward the longitudinal direction ( ⁇ Y direction) of the electrode base material 31.
- the melting portion 84 is formed by melting and solidifying the intermediate layer 83 and the electrode base material 31 by laser welding, and includes a noble metal element contained in the intermediate layer 83 and an element contained in the electrode base material 31. It is out.
- the total amount of noble metal elements in the melting portion 84 is, for example, 2.8 mass percent or less.
- the melting portion 84 is a layer for relieving thermal stress generated when the spark plug 100 is used in addition to joining the intermediate layer 83 and the electrode base material 31 to join the discharge chip 80 to the electrode base material 31. is there. *
- FIG. 2 further shows the height H1 of the discharge chip 80, the height H2 of the discharge layer 82, the height H3 of the intermediate layer 83, and the longitudinal direction ( ⁇ Y direction) of the ground electrode 30 along the axis O. ) Along the longitudinal direction of the melted portion 84 within the range in which the discharge chip 80 exists along the longitudinal direction (hereinafter, depth).
- the depth length L is also the length of the melting portion 84 from the front end 85 of the discharge chip 80 located on the other end 35 side of the electrode base material 31 toward the rear end 88 of the discharge chip 80.
- the ratio D (hereinafter, ratio D) of the depth length L to the length T is 76.2% or more and less than 100%. *
- the height H1 of the discharge chip 80 is not less than 0.30 mm and not more than 0.65 mm, and is 0.50 mm in this embodiment.
- the length T of the discharge chip 80 is 1.0 mm or more and 2.0 mm or less, and is 1.8 mm in this embodiment.
- the ratio H1 / T between the height H1 and the length T of the discharge chip 80 is not less than 0.20 and not more than 0.45, and is 0.28 in this embodiment.
- the ratio H2 / H3 between the height H2 of the discharge layer 82 and the height H3 of the intermediate layer 83 is not less than 0.30 and not more than 2.05, and is 1.0 in this embodiment.
- the area of the surface 86 facing the center electrode 20 of the discharge chip 80 is 0.75 mm 2 or more.
- FIG. 3 is a cross-sectional view of the distal end portion 32 of the ground electrode 30.
- the cross sectional view shown in FIG. 3 is a cross sectional view taken along the line AA in FIG.
- the center P of the discharge chip 80, the straight line m passing through the center P of the discharge chip 80 and parallel to the width direction (X-axis direction) of the ground electrode 30, the center line C of the ground electrode, and the discharge chip 80 2 shows a region S (region indicated by a cross hatch) where the melted portion 84 is formed.
- the center P of the discharge chip 80 is also the center of the discharge layer 82. *
- the melting portion 84 is further formed in the ⁇ Y direction beyond the straight line m.
- the melting portion 84 is located on the other end 35 side of the electrode base material 31 than the center P of the discharge chip 80 (up to the depth T / 2 of the discharge chip 80).
- the region S can be confirmed by observing the cross section of the tip 32 of the ground electrode 30, but the discharge chip can be seen from the ⁇ Z direction using X-rays (CT scan). It can also be confirmed by observing 80. *
- the spark plug 100 is manufactured as follows. First, the metal shell 50, the insulator 10, the center electrode 20, and the electrode base material 31 are prepared. Subsequently, the electrode base material 31 before being bent is joined to the metal shell 50. Apart from this, the center electrode 20 and the insulator 10 are assembled. And the assembly
- the discharge tip 80 is laser-welded to the electrode base material 31.
- a laser welding method for the electrode base material 31 and the discharge tip 80 will be described later.
- the ground electrode 30 is bent so that one side surface of the tip 32 of the ground electrode 30 faces the center electrode 20.
- the spark plug 100 is completed.
- the said manufacturing method is an example, A spark plug can be manufactured by the various methods different from this. For example, the order of the steps described above can be arbitrarily changed. *
- FIG. 4 is a flowchart showing a laser welding method between the electrode base material 31 and the discharge tip 80.
- the discharge chip 80 is disposed at a predetermined position of the electrode base material 31 (step S101).
- a recess 60 for disposing the discharge chip 80 is formed in the distal end portion 32 of the electrode base material 31, and the discharge chip 80 is disposed in the recess 60 of the distal end portion 32.
- the electrode base material 31 and the discharge tip 80 may be resistance-welded for temporary fixing, or the electrode base material 31 and the discharge tip 80 may be fixed with a jig. *
- a laser welding process is performed in which a laser is applied to the boundary portion 36 between the electrode base material 31 and the discharge tip 80 (step S103).
- FIG. 5 is a schematic diagram showing a state of the laser welding process.
- FIG. 5A is a diagram of the laser welding process viewed from the ⁇ X direction
- FIG. 5B is a diagram of the laser welding process viewed from the ⁇ Z direction.
- step S103 as shown in FIG. 5A, the boundary 36 between the electrode base material 31 and the discharge chip 80 is parallel to the boundary 36 from the + Y direction on the other end 35 side of the ground electrode 30. Is irradiated with laser LB. Further, as shown in FIG. 5B, the laser LB is scanned over the entire end face 85 of the discharge chip 80.
- the laser LB for example, a high energy fiber laser can be used.
- the laser LB does not have to be irradiated in parallel with the boundary portion 36.
- the laser LB may be irradiated with an inclination in the range of ⁇ 5 ° to 5 ° with respect to the boundary portion 36 in the Z direction.
- the melted portion 84 is formed at least in the region on the other end 35 side of the electrode base material 31 from the center P of the discharge chip 80 when the discharge chip 80 is viewed from the ⁇ Z direction, and Laser is irradiated so that the ratio D becomes 76.2% or more, and the melted portion 84 is formed.
- a melting portion 84 has obtained a relationship between the laser output value, the laser scanning speed, the region S, and the ratio D by experiment, and the region S is at least from the center P of the discharge chip 80.
- the melted portion 84 is sufficiently formed in the region on the other end 35 side of the electrode base material 31, and the depth length of the melted portion 84 is sufficiently secured. Therefore, it is possible to suppress the discharge chip 80 including the discharge layer 82 and the intermediate layer 83 from warping from the electrode base material 31. Therefore, the peeling resistance of the discharge chip 80 can be improved. Further, since the discharge chip 80 is a clad material including the discharge layer 82 and the intermediate layer 83, the discharge layer 82 improves the durability of the spark plug 100, and the intermediate layer 83 allows the discharge layer 82 and the electrode base material 31 to be improved. It is possible to relieve the thermal stress generated by the difference in the linear expansion coefficient. *
- the area of the surface 86 facing the center electrode 20 of the discharge chip 80 is 0.75 mm 2 or more, the durability of the spark plug 100 can be improved.
- the melting part 84 when the melting part 84 is viewed from the ⁇ Z direction when the discharge chip 80 is viewed, it is formed at least in a region closer to the other end 35 of the electrode base material 31 than the center P of the discharge chip 80, and the ratio D is The grounds for configuring the spark plug 100 to satisfy 76.2% or more will be described based on experimental results. *
- FIG. 6 is a graph showing the results of experiments conducted to obtain the optimum range of the ratio D.
- the ratio D is varied by changing the output value of the laser LB and the scan speed, and the discharge shown below for each ratio D.
- Three spark plugs were produced for each shape and material of the chip 80.
- the discharge chip 80 when the discharge chip 80 was viewed from the ⁇ Z direction, the laser LB was irradiated so that the melted portion 84 was formed at least in the region on the other end 35 side of the electrode base material 31.
- the discharge chip 80 a discharge chip having the following three types of shapes and materials was used. Inconel 601 was used as the material of the electrode base material 31. *
- a cooling test was performed.
- the tip 32 of the ground electrode 30 was first heated with a burner for 2 minutes to raise the temperature of the ground electrode 30 to 1050 ° C. Thereafter, the burner was turned off, the ground electrode 30 was gradually cooled for 1 minute, and the ground electrode 30 was heated again with the burner for 2 minutes to raise the temperature of the ground electrode 30 to 1050 ° C. This cycle was repeated 1000 times. *
- the ground electrode 30 was cut in parallel with the axis O, including the center line C of the ground electrode 30.
- this cross section (longitudinal cross section shown in FIG. 2), the length of the boundary portion 36 where the intermediate layer 83 and the electrode base material 31 are not melted, and the length of the oxide scale and crack of the molten portion 84 generated near the boundary portion 36. And the combined length were measured.
- the ratio K of the combined length to the length T of the discharge chip was obtained. The smaller the ratio K, the lower the possibility that the discharge chip 80 will peel off from the electrode base material 31.
- melting part 84 with respect to the length T of the discharge chip 80 was calculated
- the ratio D and the ratio K of the three spark plugs produced on the same conditions were averaged, respectively, and the relationship between the ratio D and the ratio K was calculated
- the ratio K decreases. That is, the longer the length of the welded portion between the discharge tip 80 and the electrode base material 31, the lower the possibility that the discharge tip 80 peels from the electrode base material 31.
- the ratio D is 76.2% or more
- the ratio K is significantly smaller than the ratio D of less than 76.2%, and the generation of oxide scale and cracks can suppress the peeling of the discharge chip 80. It was found to be suppressed. There was no significant difference in peel resistance depending on the shape of the discharge tip. *
- the melting portion 84 is formed at least in the region on the other end 35 side of the electrode base material 31 with respect to the center P of the discharge chip 80. It was shown that the ratio D of the depth length L of the fusion zone 84 to the length T of the chip 80 is preferably 76.2% or more.
- FIG. 7 is a longitudinal sectional view of the tip end portion 32a of the ground electrode 30a of the spark plug in the second embodiment.
- the longitudinal sectional view shown in FIG. 7 is parallel to the axis O and includes the center line C of the ground electrode 30.
- the end surface 87a of the intermediate layer 83a of the discharge chip 80a is exposed on the other end 35a side of the electrode base material 31a.
- the spark plug according to the present embodiment similarly to the spark plug according to the first embodiment, when the melting portion 84a views the discharge chip 80a from the ⁇ Z direction, the discharge chip 80a (discharge layer 82) is seen.
- the ratio D of the depth length L of the melting portion 84a is 76.2% or more. Since the other structure of the spark plug is the same as that of the spark plug 100 of the first embodiment, the description thereof is omitted.
- the ground electrode 30a whose end face 87a is exposed on the other end 35a side of the electrode base material 31a is the output value of the laser LB or the laser so that the end face 87a is exposed in the laser welding step (FIG. 4, step S103). It can be manufactured by appropriately adjusting the scanning speed of the LB and the irradiation angle with respect to the boundary portion 36a of the laser LB. *
- the intermediate layer 83a contains the most precious metal element contained in the discharge layer 82a, compared to a melted portion 84a formed by melting the electrode base material 31a and the intermediate layer 83a, spark consumption is reduced. High nature.
- the end surface 87a of the intermediate layer 83a of the discharge chip 80a is exposed on the other end 35a side of the electrode base material 31a. Therefore, even when the spark plug discharges on the tip 85a side of the discharge chip 80a, compared to the spark plug 100 of the first embodiment in which the intermediate layer 83 is covered by the melting portion 84, the consumption of sparks is reduced. The sex can be further improved.
- FIG. 7 shows a state in which the end surface 87a of the intermediate layer 83a is exposed in a longitudinal sectional view including the center line C of the ground electrode 30a, but the end surface 87a is the other end 35a of the electrode base material 31a. If the spark plug is exposed on the side, the same effects as those of the second embodiment can be obtained. *
- the discharge chips 80 and 80a include the discharge layers 82 and 82a and the intermediate layers 83 and 83a one by one.
- the discharge chip 80c may include an intermediate layer having a two-layer structure, or may include an intermediate layer that is multilayered from two layers.
- FIG. 8 is a longitudinal sectional view of the tip 32c of the ground electrode 30c.
- the discharge chip 80c includes a discharge layer 82c, a first intermediate layer 83b, and a second intermediate layer 83c.
- the first intermediate layer 83b includes a noble metal element (for example, Pt) that is contained most in the discharge layer 82c and an element (for example, Ni) that is included in the electrode base material 31c.
- the second intermediate layer 83c contains a smaller amount of the noble metal element (for example, Pt) contained most in the discharge layer 82c than in the first intermediate layer 83b.
- the second intermediate layer 83c contains more elements (for example, Ni) contained in the electrode base material 31c than the first intermediate layer 83b. *
- the second intermediate layer 83c contains more elements (for example, Ni) contained in the electrode base material 31c than the first intermediate layer 83b. Compared with the case where only the layer 83b is provided, it is easily melted by the electrode base material 31c. Therefore, since the ratio D of the depth length L of the fusion
- the discharge chips 80 and 80a are columnar in shape with the surfaces 86 and 86a facing the center electrode 20 being square.
- the shape of the discharge chips 80 and 80a may be, for example, a columnar shape in which the shape of the surfaces 86 and 86a facing the center electrode 20 is a rectangular shape, or may be a cylindrical shape. That is, the shape of the discharge chips 80 and 80a is not limited to the above embodiment, and any shape can be adopted.
- FIG. 9 is a vertical cross-sectional view of the distal end portion 32f of the ground electrode 30f.
- the longitudinal sectional view shown in FIG. 9 is parallel to the axis O and includes the center line C of the ground electrode 30f.
- FIG. 10 is a cross-sectional view of the distal end portion 32f of the ground electrode 30f.
- FIG. 10 is a cross-sectional view taken along the line BB in FIG. 9 and includes a boundary portion 36f.
- the shape of the discharge chip 80f shown in FIGS. 9 and 10 is a columnar shape in which the shape of the surface 86f facing the center electrode 20 is a rectangular shape. Even in the discharge chip 80f having such a shape, as shown in FIG.
- the ratio D of the depth length L to the length T of the melting portion 84f is 76.2% or more, as shown in FIG.
- the melting portion 84f is at least formed in the region on the other end 35f side of the electrode base material 31f with respect to the center P of the discharge tip 80f (discharge layer 82f).
- FIG. 11 is a longitudinal sectional view of the tip 32e of the ground electrode 30e.
- the longitudinal sectional view shown in FIG. 11 is parallel to the axis O and includes the center line C of the ground electrode 30e.
- FIG. 12 is a cross-sectional view of the tip 32e of the ground electrode 30e.
- FIG. 12 is a cross-sectional view taken along line EE in FIG. 11 and includes a boundary portion 36e.
- the other end 35e of the ground electrode 30e and the tip 85e of the discharge chip 80e are not aligned and are not located on the same XZ plane.
- the melting portion 84 has a depth D ratio D of 76.2% or more.
- the end face 87e of the intermediate layer 83e is exposed. Further, as shown in FIG. 12, when the discharge tip 80e is viewed from the ⁇ Z direction, the melting portion 84e is closer to the other end 35e side of the electrode base material 31e than the center P of the discharge tip 80e (discharge layer 82e). At least formed in the region. Even a spark plug having such a ground electrode 30e has the same effects as those of the second embodiment. *
- the discharge tips 80 and 80a are laser welded to the recesses 60 of the electrode base materials 31 and 31a.
- the discharge tips 80 and 80a may be directly welded to the flat surfaces of the electrode base materials 31 and 31a without providing the recess 60 in the electrode base materials 31 and 31a.
- the ratio D of the depth length L of the fusion zone is 76.2% or more and less than 100%. On the other hand, the ratio D may be 100% or more.
- FIG. 13 is a longitudinal sectional view of the tip 32d of the ground electrode 30d.
- the longitudinal sectional view shown in FIG. 13 is parallel to the axis O and includes the center line C of the ground electrode 30d.
- the ratio D of the depth length L is 100% or more.
- the depth L of the melting portion 84d may be measured by measuring the length L along the longitudinal direction from the front end 85d of the discharge chip 80d toward the rear end 88d. Although illustration is omitted, when the discharge tip 80d is viewed from the ⁇ Z direction, the melting portion 84d is formed at least in a region closer to the other end 35d of the electrode base material 31d than the center P of the discharge tip 80d. Yes. *
- the discharge chip 80d can be further prevented from warping from the electrode base material 31d, and the peel resistance of the discharge chip 80d can be further improved. . *
- the area of the surface 86 facing the center electrode 20 of the discharge chip 80 is 0.75 mm 2 or more. On the other hand, the area of the surface 86 may be less than 0.75 mm 2 .
- the present invention is not limited to the above-described embodiments and modifications, and can be realized with various configurations without departing from the spirit thereof.
- the technical features in the embodiments and the modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.
- boundary part 40 ... terminal fitting 50 ... main body Metal fitting 51 ... Tool engaging part 52 ... Mounting screw part 53 ... Casting part 54 ... Seal part 56: metal fitting inner step 57 ... tip surface 58 ... compression deformation part 60 ... dent 80, 80a, 80c, 80d, 80e, 80f ... discharge chip 82, 82a, 82c, 82d, 82e, 82f ... discharge layer 83, 83a, 83e ... intermediate layer 83b ... first intermediate layer 83c ... second intermediate layer 84, 84a, 84c, 84d, 84f ... melting part 85, 85d, 85e ... discharging tip tips 86, 86f ...
- discharging tip center electrode Opposing surfaces 87a, 87e ... end face of intermediate layer 88, 88d ... rear end of discharge tip 100 ... spark plug C ... center line of ground electrode G ... discharge gap LB ... laser O ... axis P ... center of discharge layer S ... area m ... straight line
Landscapes
- Spark Plugs (AREA)
Abstract
Description
とにより形成される。
a)の中心Pよりも電極母材31aの他端35a側の領域に少なくともに形成されており、溶融部84aの奥行き長さLの割合Dは76.2%以上である。スパークプラグのその他の構成は、第1実施形態のスパークプラグ100と同様であるため説明を省略する。
Claims (4)
- 軸線方向に延びる中心電極と、 軸孔を有し前記中心電極が前記軸孔に設けられる絶縁体と、 前記絶縁体を保持する筒状の主体金具と、 前記主体金具の先端に一端部が接続される電極母材と、前記電極母材の他端部の内側面に接合され、前記中心電極と間隙を介して対向する放電チップと、を有する接地電極と、
を備えるスパークプラグであって、
前記放電チップは、
前記中心電極側に配置された貴金属又は貴金属合金を含む放電層と、
一端が前記放電層に接合され、他端の少なくとも一部が溶融部を介して前記電極母材と接合されるとともに、前記放電層に含まれる貴金属元素のうち最も多く含まれる貴金属元素を前記放電層よりも少量含む中間層と、を有し、
前記溶融部は、前記軸線方向から前記放電チップを見た場合に、前記放電層の中心よりも前記電極母材の他端側の領域に少なくとも形成されており、
前記接地電極の長手方向に沿った中心線を含み前記軸線と平行な断面において、前記長手方向に沿った前記放電チップの長さに対する、前記長手方向に沿って前記放電チップが存在する範囲内における前記溶融部の前記長手方向に沿った長さの割合は、76.2%以上である、 スパークプラグ。 - 請求項1に記載のスパークプラグであって、
前記電極母材の他端側において、前記中間層の端面が露出する、スパークプラグ。 - 請求項1又は請求項2に記載のスパークプラグであって、
前記放電チップの前記中心電極と対向する面の面積は、0.75mm2以上である、スパークプラグ。 - 請求項1から請求項3までのいずれか一項に記載のスパークプラグであって、
前記割合は100%以上である、スパークプラグ。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP16841017.3A EP3346559A4 (en) | 2015-09-04 | 2016-06-08 | SPARK PLUG |
US15/755,746 US10181702B2 (en) | 2015-09-04 | 2016-06-08 | Spark plug |
KR1020187005960A KR20180037007A (ko) | 2015-09-04 | 2016-06-08 | 스파크 플러그 |
CN201680051036.XA CN107925221A (zh) | 2015-09-04 | 2016-06-08 | 火花塞 |
Applications Claiming Priority (2)
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JP2015-174520 | 2015-09-04 | ||
JP2015174520A JP6105694B2 (ja) | 2015-09-04 | 2015-09-04 | スパークプラグ |
Publications (1)
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WO2017037969A1 true WO2017037969A1 (ja) | 2017-03-09 |
Family
ID=58186779
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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PCT/JP2016/002771 WO2017037969A1 (ja) | 2015-09-04 | 2016-06-08 | スパークプラグ |
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US (1) | US10181702B2 (ja) |
EP (1) | EP3346559A4 (ja) |
JP (1) | JP6105694B2 (ja) |
KR (1) | KR20180037007A (ja) |
CN (1) | CN107925221A (ja) |
WO (1) | WO2017037969A1 (ja) |
Families Citing this family (3)
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JP6793154B2 (ja) * | 2018-06-13 | 2020-12-02 | 日本特殊陶業株式会社 | スパークプラグ |
DE112020005849T5 (de) * | 2019-11-29 | 2022-09-08 | Ngk Spark Plug Co., Ltd. | Zündkerze |
JP7121081B2 (ja) * | 2020-08-19 | 2022-08-17 | 日本特殊陶業株式会社 | スパークプラグ |
Citations (6)
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JPS59160988A (ja) * | 1983-03-02 | 1984-09-11 | 日本特殊陶業株式会社 | スパ−クプラグ |
JPS61135080A (ja) * | 1984-12-05 | 1986-06-23 | 日本特殊陶業株式会社 | スパ−クプラグ |
JPS61135081A (ja) * | 1984-12-06 | 1986-06-23 | 日本特殊陶業株式会社 | スパ−クプラグ |
WO2009081563A1 (ja) * | 2007-12-20 | 2009-07-02 | Ngk Spark Plug Co., Ltd. | スパークプラグ及びその製造方法 |
JP2010238498A (ja) * | 2009-03-31 | 2010-10-21 | Ngk Spark Plug Co Ltd | スパークプラグ |
JP2013041754A (ja) * | 2011-08-17 | 2013-02-28 | Ngk Spark Plug Co Ltd | スパークプラグ |
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US5465022A (en) | 1992-08-12 | 1995-11-07 | Nippondenso Co., Ltd. | Spark plug for internal-combustion engine and manufacture method of the same |
JP3724815B2 (ja) | 1992-08-12 | 2005-12-07 | 株式会社デンソー | 内燃機関用スパークプラグ |
EP2211433B1 (en) * | 2007-11-15 | 2019-01-16 | NGK Spark Plug Co., Ltd. | Spark plug |
JP4705129B2 (ja) * | 2008-05-21 | 2011-06-22 | 日本特殊陶業株式会社 | スパークプラグ |
EP2348590B1 (en) * | 2008-11-21 | 2018-05-02 | Ngk Spark Plug Co., Ltd. | Spark plug for internal combustion engine |
EP3624279B1 (en) * | 2010-09-29 | 2021-11-24 | NGK Spark Plug Co., Ltd. | Spark plug |
DE112011103796B4 (de) * | 2010-11-17 | 2019-10-31 | Ngk Spark Plug Co., Ltd. | Zündkerze |
JP5835704B2 (ja) * | 2011-08-03 | 2015-12-24 | 日本特殊陶業株式会社 | スパークプラグ |
US9368943B2 (en) * | 2013-03-12 | 2016-06-14 | Federal-Mogul Ignition Company | Spark plug having multi-layer sparking component attached to ground electrode |
-
2015
- 2015-09-04 JP JP2015174520A patent/JP6105694B2/ja not_active Expired - Fee Related
-
2016
- 2016-06-08 US US15/755,746 patent/US10181702B2/en not_active Expired - Fee Related
- 2016-06-08 CN CN201680051036.XA patent/CN107925221A/zh active Pending
- 2016-06-08 EP EP16841017.3A patent/EP3346559A4/en not_active Withdrawn
- 2016-06-08 WO PCT/JP2016/002771 patent/WO2017037969A1/ja active Application Filing
- 2016-06-08 KR KR1020187005960A patent/KR20180037007A/ko active IP Right Grant
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JPS59160988A (ja) * | 1983-03-02 | 1984-09-11 | 日本特殊陶業株式会社 | スパ−クプラグ |
JPS61135080A (ja) * | 1984-12-05 | 1986-06-23 | 日本特殊陶業株式会社 | スパ−クプラグ |
JPS61135081A (ja) * | 1984-12-06 | 1986-06-23 | 日本特殊陶業株式会社 | スパ−クプラグ |
WO2009081563A1 (ja) * | 2007-12-20 | 2009-07-02 | Ngk Spark Plug Co., Ltd. | スパークプラグ及びその製造方法 |
JP2010238498A (ja) * | 2009-03-31 | 2010-10-21 | Ngk Spark Plug Co Ltd | スパークプラグ |
JP2013041754A (ja) * | 2011-08-17 | 2013-02-28 | Ngk Spark Plug Co Ltd | スパークプラグ |
Non-Patent Citations (1)
Title |
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See also references of EP3346559A4 * |
Also Published As
Publication number | Publication date |
---|---|
CN107925221A (zh) | 2018-04-17 |
EP3346559A4 (en) | 2019-04-17 |
JP6105694B2 (ja) | 2017-03-29 |
KR20180037007A (ko) | 2018-04-10 |
JP2017050234A (ja) | 2017-03-09 |
US10181702B2 (en) | 2019-01-15 |
US20180248340A1 (en) | 2018-08-30 |
EP3346559A1 (en) | 2018-07-11 |
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