Patents by Inventor Mamoru Musasa
Mamoru Musasa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20120176019Abstract: Problem is to enhance the welding strength when a projecting shape section is resistance-welded to a around electrode. A ground electrode 30 includes a ground electrode base material 35 and a projecting shape section 36. The projecting shape section 36 is connected by resistance welding to an opposite surface 32 of the ground electrode 30 so as to be opposite and project towards the leading end of a center electrode 20. The ground electrode base material 35 and the projecting shape section 36 are formed from a material that is composed of the same metal (for example, nickel) as a main component and have a relation of formulas (1) and (2) described below. In formula (1), the specific resistance of the ground electrode base material 35 is R (??cm) and the specific resistance of the projecting shape section 36 is S (??cm). The specific resistance R>the specific resistance S . . . (formula 1), the specific resistance R? specific resistance S?20 . . . (formula 2).Type: ApplicationFiled: August 4, 2010Publication date: July 12, 2012Applicant: NGK SPARK PLUG CO., LTD.Inventors: Akira Suzuki, Mamoru Musasa
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Patent number: 8212461Abstract: A spark plug including: a rod-shaped center electrode; an insulator; a metal shell; a ground electrode joined to the metal shell and bent toward the center electrode; a noble metal tip joined to an end portion of the ground electrode and opposing a leading end portion of the center electrode via a gap; and a bulge portion. A part of the noble metal tip is embedded in the ground electrode, and another part of the noble metal tip protrudes from a distal end surface of the ground electrode. A relationship A?0.25 mm is satisfied where A (mm) is a protruding length of the noble metal tip from the distal end surface. The bulge portion covers a center part of a boundary between the noble metal tip and the end surface in a width direction.Type: GrantFiled: November 20, 2008Date of Patent: July 3, 2012Assignee: NGK Spark Plug Co., Ltd.Inventors: Hiroyuki Kameda, Mamoru Musasa
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Patent number: 8207657Abstract: A spark plug capable of increasing a welding strength between a leading end of a metal shell and a base end of a ground electrode to avoid fracture of a welded part due to vibrations and the like even when making the metal shell smaller. The spark plug satisfies a relation of S2?S wherein S2 is a sectional area of the welded part between the metal shell and the ground electrode, the sectional area S2 being cut off by a plane including a leading end surface of the metal shell, and S is a sectional area of the ground electrode, the sectional area S being cut off by a plane passing to the most axial leading end of a boundary between the ground electrode and the welded part and perpendicular to the axial direction.Type: GrantFiled: November 4, 2009Date of Patent: June 26, 2012Assignee: NGK Spark Plug Co., Ltd.Inventors: Akira Suzuki, Mamoru Musasa
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Publication number: 20120146484Abstract: A generation of a stress corrosion cracking is prevented in a middle section. The spark plug 1 includes an insulator 2 that extends along an axis CL1 direction and a metal shell 3. The metal shell 3 includes a middle section 41 that is positioned between a collar section 16 and a tool engaging section 19. The middle section 41 has a bulged section 42 that bulges towards both the inside and the outside in the diametrical direction, a first slender section 43 that is the most slender at a portion that is positioned further to the rear end side in the axis CL1 direction than the bulged section 42 and a second slender section 44 that is the most slender at a portion that is positioned further to the leading end side in the axis CL1 direction than the bulged section 42 and the bulged section 42 has the most bulged section 42M that bulges toward the most inside of diametrical direction.Type: ApplicationFiled: June 23, 2010Publication date: June 14, 2012Applicant: NGK SPARK PLUG CO., LTD.Inventors: Akira Suzuki, Mai Nakamura, Mamoru Musasa
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Patent number: 8143773Abstract: When an insulator of a spark plug receives an external force in a bending direction perpendicular to an axis at a rear end side body portion, a position C where the insulator is supported by a crimping portion via a packing acts as a fulcrum, and a stress is applied between the position C and a position B where the insulator is supported by a ledge portion via a packing. When an insulator is designed in which the balance of size and modulus of section is adjusted so that ?A which denotes a proof strength against bending between a rear end position A of the insulator and the position C and ?B which denotes a proof strength against bending between the position B and the position C satisfy 0.71??A/?B?1.27, cracks can be prevented.Type: GrantFiled: March 17, 2009Date of Patent: March 27, 2012Assignee: NGK Spark Plug Co., Ltd.Inventors: Akira Suzuki, Tomoaki Kato, Mamoru Musasa
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Publication number: 20120062099Abstract: An object of the invention is to restrain separation of an electrode tip from a ground electrode or from a center electrode. A spark plug satisfies a condition 0.8?A1/A2?1.9, where, as viewed on a section which contains a center axis (O) of an electrode tip, A1 [Hv] is hardness of the electrode tip as measured outside a circle having a radius of 0.2 mm, with a boundary point (PA) on a surface of the spark plug between a fusion zone and the electrode tip serving as the center of the circle, and A2 [Hv] is hardness of the electrode tip as measured within the circle having a radius of 0.2 mm.Type: ApplicationFiled: April 5, 2010Publication date: March 15, 2012Inventors: Naomichi Miyashita, Mamoru Musasa
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Patent number: 8098004Abstract: A spark plug (100) including a center electrode (130) and a ground electrode (140), which is formed by joining a ground electrode chip (143) to a ground electrode base material (141) via an intermediate member (142). A method for producing the spark plug (100) includes providing a projecting portion (142p) on the intermediate member (142), and projection-welding the intermediate member (142) to the ground electrode base material (141) by means of the projecting portion (142p), to thereby join the intermediate member 142 to the ground electrode base material (141). Further, the intermediate member (142) of the spark plug (100) includes a cylindrical columnar portion (142e) which is joined to the ground electrode chip (143), and a flange portion (142d) which is joined to the ground electrode base material (141) and which flange portion (142d) has a diameter greater than that of the cylindrical columnar portion (142e).Type: GrantFiled: July 29, 2010Date of Patent: January 17, 2012Assignee: NGK Spark Plug Co., Ltd.Inventors: Tomoaki Kato, Kazuyoshi Torii, Mamoru Musasa
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Publication number: 20110294369Abstract: The present invention provides a spark plug which is capable of suppressing a occurrence of crack and separation by determining a structural configuration of a melting portion formed in a junction portion between a discharge portion and a pedestal portion which form an ignition portion that protrudes from a ground electrode. In a profile line shape of a cross section including a center axis P of an ignition portion 80, an exposure surface 88 of a melting portion 83 connects a side surface 82 of a discharge portion 81 and a side surface 85 of a pedestal portion 84. Further, an exterior angle ? formed between an imaginary line Q, which passes through a boundary position X1 between the melting portion 83 and the pedestal portion 84 and a boundary position X2 between the melting portion 83 and the discharge portion 81, and the center axis P at a node C, satisfies 135°???175°.Type: ApplicationFiled: January 27, 2010Publication date: December 1, 2011Applicant: NGK SPARK PLUG CO., LTD.Inventors: Naomichi Miyashita, Mamoru Musasa, Akira Suzuki, Kazuyoshi Torii, Tomoaki Kato
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Patent number: 8052495Abstract: A spark plug (100) including a center electrode (130) and a ground electrode (140), which is formed by joining a ground electrode chip (143) to a ground electrode base material (141) via an intermediate member (142). A method for producing the spark plug (100) includes providing a projecting portion (142p) on the intermediate member (142), and projection-welding the intermediate member (142) to the ground electrode base material (141) by means of the projecting portion (142p), to thereby join the intermediate member 142 to the ground electrode base material (141). Further, the intermediate member (142) of the spark plug (100) includes a cylindrical columnar portion (142e) which is joined to the ground electrode chip (143), and a flange portion (142d) which is joined to the ground electrode base material (141) and which flange portion (142d) has a diameter greater than that of the cylindrical columnar portion (142e).Type: GrantFiled: March 27, 2008Date of Patent: November 8, 2011Assignee: NGK Spark Plug Co., Ltd.Inventors: Tomoaki Kato, Kazuyoshi Torii, Mamoru Musasa
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Publication number: 20110266940Abstract: A spark plug which provides reliable prevention of adhesion and accumulation of carbon on an insulator, includes a center electrode extending in the direction of an axis CL1, a ceramic insulator having an axial hole which extends in the direction of the axis CL1 and in which the center electrode is provided, a cylindrical metallic shell provided externally of the outer circumference of the insulator and having a support portion formed on the inner circumferential surface thereof, and a ground electrode extending from a front end portion of the metallic shell. The insulator has a stepped portion supported by the support portion of the metallic shell, and a leg portion formed forward of the stepped portion. A space SP formed between the leg portion of the insulator and the inner circumferential surface of the metallic shell has a volume of 100 mm3 to 300 mm3 inclusive.Type: ApplicationFiled: December 7, 2009Publication date: November 3, 2011Applicant: NGK Spark Plug Co., Ltd.Inventors: Akira Suzuki, Tomoaki Kate, Mamoru Musasa, Toshitaka Honda
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Patent number: 8044562Abstract: There is provided a spark section (80) of needle-like shape protruding from an inner surface (33) of a ground electrode (30) to define a spark gap between the spark section and an electrode tip on a center electrode. The spark section (80) has a noble metal member (81) and an intermediate member (86) joined to each other. The materials of the noble metal member (81) and the intermediate member (86) are selected in such a manner that the thermal conductivity of the intermediate member (86) is lower than that of the noble metal member (81). This limits heat radiation through the heat radiation passage from the noble metal member (81) through the intermediate member (86) to the ground electrode (30) so as to maintain the noble metal member (81) at a higher temperature than conventional types and reduce a quenching effect of the noble metal member (81) on a flame core generated in the spark gap for improvement in ignition performance.Type: GrantFiled: November 12, 2008Date of Patent: October 25, 2011Assignee: NGK Spark Plug Co., Ltd.Inventors: Mamoru Musasa, Naomichi Miyashita, Kazuyoshi Torii
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Publication number: 20110254428Abstract: [Objective] To provide a spark plug which is configured such that an insulation member, from which a center electrode projects, is pressed frontward and held in a metallic shell, and is fixed by means of crimping the rear end of the metallic shell, and which can prevent a drop in gas tightness between the metallic shell and the insulation member due to a difference in thermal expansion therebetween. [Means for Solution] In a spark plug in which a mating shaft portion (10) of an insulation member (1) is loose-fitted into a mating hole portion (30) of a metallic shell (21), a filler (41) for maintaining gas tightness is charged between the outer circumferential surface of the mating shaft portion (10) and the inner circumferential surface of the mating hole portion (30). Despite the thermal expansion difference, the gas tightness is maintained, because the filler (41) for maintaining gas tightness is charged between the inner and outer circumferential surfaces.Type: ApplicationFiled: December 22, 2009Publication date: October 20, 2011Inventors: Jiro Kyuno, Akira Suzuki, Mamoru Musasa
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Patent number: 8033880Abstract: A method for manufacturing a spark plug which includes: (a) preparing a metal shell; (b) preparing an insulator; (c) inserting the insulator in an insertion hole of the metal shell; (d) forming an intended crimping portion of the metal shell into a crimping portion; and (e) pressing a lower side portion of the metal shell closer to a position lower than the intended compressive deformation portion, and pressing the crimping portion of the metal shell in an axial direction to compressively deform the intended compressive deformation portion of the metal shell and thus seal a space between a stepped portion of the metal shell and a stepped portion of the insulator, wherein step (e) controls a pressing amount of a press in a constant value from the start of compressive deformation to the end thereof.Type: GrantFiled: February 9, 2010Date of Patent: October 11, 2011Assignee: NGK Spark Plug Co., Ltd.Inventors: Akira Suzuki, Mai Nakamura, Mamoru Musasa
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Publication number: 20110198982Abstract: A spark plug capable of increasing a welding strength between a leading end of a metal shell and a base end of a ground electrode to avoid fracture of a welded part due to vibrations and the like even when making the metal shell smaller. The spark plug satisfies a relation of S2?S wherein S2 is a sectional area of the welded part between the metal shell and the ground electrode, the sectional area S2 being cut off by a plane including a leading end surface of the metal shell, and S is a sectional area of the ground electrode, the sectional area S being cut off by a plane passing to the most axial leading end of a boundary between the ground electrode and the welded part and perpendicular to the axial direction.Type: ApplicationFiled: November 4, 2009Publication date: August 18, 2011Applicant: NGK SPARK PLUG CO., LTD.Inventors: Akira Suzuki, Mamoru Musasa
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Publication number: 20110163653Abstract: A spark plug includes a cylindrical metal shell; a cylindrical insulator that is held in the metal shell; a center electrode; and a ground electrode that comprises a ground electrode main body part and a noble metal tip, a spark discharge gap being formed between the leading end of the center electrode and the noble metal tip wherein at least a portion of the ground electrode main body part, to which the noble metal tip is joined, is made of Ni alloy containing 12 to 35 mass % of Cr, 7 mass % or less of Fe, 0.5 to 5 mass % of Al, 0.3 to 5 mass % of Si and 50 mass % or more of the balance, and wherein the joined portion and the noble metal tip are joined by laser welding or electron beam welding.Type: ApplicationFiled: September 9, 2009Publication date: July 7, 2011Applicant: NGK SPARK PLUG CO., LTD.Inventors: Kazuyoshi Torii, Tomoo Tanaka, Akira Suzuki, Mamoru Musasa, Naomichi Miyashita, Osamu Yoshimoto
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Patent number: 7944134Abstract: A spark plug including: a center electrode including an electrode base member and a core member; an electrode tip joined to the center electrode via a molten bond; an insulator holding the center electrode; a metal shell holding the insulator; and a ground electrode joined to the metal shell. Relationships d?2.1 [mm] and ?0.09×d+0.33<Vb/(Va+Vb)<?0.2×d+0.75 are satisfied, where d is an outer diameter of the center electrode at a position 4 mm closer to the base end of the center electrode from the base end of the molten bond in the axial direction, and Va and Vb are volumes of the electrode base member and the core member, respectively, at a region between the base end of the molten bond and the position in the axial direction.Type: GrantFiled: November 21, 2008Date of Patent: May 17, 2011Assignee: NGK Spark Plug Co., Ltd.Inventors: Jiro Kyuno, Akira Suzuki, Mai Moribe, Yuichi Nakano, Mamoru Musasa
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Publication number: 20110045731Abstract: To provide a method of producing a spark plug in which a spark discharge gap with a suitable distance can easily be obtained without bending to deform a ground electrode in a direction in which the ground electrode moves towards or away from a metal tip of a center electrode, in the method of producing a spark plug, when a metal tip (a noble metal tip) 21 is welded to a front end portion 13a of a center electrode 13, the metal tip 21 is welded to the front end portion 13a of the center electrode 13 after a state is established in which the metal tip 21 alone is positioned in a radial direction where a predetermined spark discharge gap g is formed relative to a distal end portion 14b of a ground electrode 14 which is joined to a metal shell 11 at a proximal end portion 14a thereof.Type: ApplicationFiled: April 22, 2009Publication date: February 24, 2011Applicant: NGK SPARK PLUG CO., LTD.Inventors: Mamoru Musasa, Akira Suzuki
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Publication number: 20110025185Abstract: A spark member (70) is formed by joining a noble metal member (71) and an intermediate member (75) and is provided in a spark discharge gap between a center electrode and a ground electrode (30). A bottom surface (80) of the intermediate member (75) is resistance-welded to an inner surface (33) of the ground electrode (30), and a weld metal zone (73) is formed in the region of joint therebetween. As viewed on the section of the spark member (70) which contains a centerline (Q), the weld metal zone (73) is reliably formed within the range of the length (D) of a columnar portion (76) as measured along a direction orthogonal to the projecting direction of the spark member (70) and has a length (d) of at least 0.1 times (10% of) the length (D).Type: ApplicationFiled: December 25, 2008Publication date: February 3, 2011Applicant: NGK Spark Plug Co., Ltd.Inventors: Kazuyoshi Torii, Akira Suzuki, Naomichi Miyashita, Mamoru Musasa, Kenji Moritani
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Publication number: 20110018422Abstract: When an insulator of a spark plug receives an external force in a bending direction perpendicular to an axis at a rear end side body portion, a position C where the insulator is supported by a crimping portion via a packing acts as a fulcrum, and a stress is applied between the position C and a position B where the insulator is supported by a ledge portion via a packing. When an insulator is designed in which the balance of size and modulus of section is adjusted so that ?A which denotes a proof strength against bending between a rear end position A of the insulator and the position C and ?B which denotes a proof strength against bending between the position B and the position C satisfy 0.71??A/?B?1.27, cracks can be prevented.Type: ApplicationFiled: March 17, 2009Publication date: January 27, 2011Applicant: NGK SPARK PLUG CO., LTD.Inventors: Akira Suzuki, Tomoaki Kato, Mamoru Musasa
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Publication number: 20100289398Abstract: A spark plug (100) including a center electrode (130) and a ground electrode (140), which is formed by joining a ground electrode chip (143) to a ground electrode base material (141) via an intermediate member (142). A method for producing the spark plug (100) includes providing a projecting portion (142p) on the intermediate member (142), and projection-welding the intermediate member (142) to the ground electrode base material (141) by means of the projecting portion (142p), to thereby join the intermediate member 142 to the ground electrode base material (141). Further, the intermediate member (142) of the spark plug (100) includes a cylindrical columnar portion (142e) which is joined to the ground electrode chip (143), and a flange portion (142d) which is joined to the ground electrode base material (141) and which flange portion (142d) has a diameter greater than that of the cylindrical columnar portion (142e).Type: ApplicationFiled: July 29, 2010Publication date: November 18, 2010Applicant: NGK SPARK PLUG CO., LTD.Inventors: Tomoaki KATO, Kazuyoshi TORII, Mamoru MUSASA