Abstract: A spark plug comprising a center electrode, a ground electrode disposed on the center electrode across a gap, and a tip joined to an opposed surface of the ground electrode that is opposed to the center electrode, the tip has a discharge layer and a relieving layer, the relieving layer is formed from a Pt—Ni alloy and joined to the opposed surface via a diffusion layer, the discharge layer is formed from a Pt—Rh alloy and joined via a clad diffusion layer to a side of the relieving layer opposite to a side of the relieving layer at which the ground electrode is joined, and 0.81?A/B?1.21 is satisfied when an average cross-sectional area of the discharge layer is A mm2 and an average cross-sectional area of the relieving layer is B mm2, and a method for producing the spark plug.

Abstract: A spark plug that includes a center electrode and a ground electrode. The center electrode is disposed providing a gap with the center electrode. At least one of the center electrode and the ground electrode includes a tip forming the gap. The tip includes a main body portion and a front surface layer. A composition of the main body portion is Pt as a main constituent and Rh of 5 mass % or more and Ni of 0 mass % or more to less than 8 mass %. The front surface layer is disposed at least at a surface radially outside of an axial line extending in a direction from a center of the main body portion to the gap. The front surface layer contains Ni of 8 mass % or more and has a thickness of 2 ?m or more.

Abstract: A storage unit of a relaying apparatus stores first identification information that identifies an SIP terminal and second identification that identifies other SIP terminal which is forecast as a transfer destination of a message. A transmitting-and-receiving unit receives from the SIP terminal a request message that is received before a transfer message to be transferred to other SIP terminal and that includes a processing request concerning communications and the first identification information. An obtaining unit obtains from a storage unit the second identification information corresponding to the first identification information included in the received request message. A connection establishing unit establishes communications between the other SIP terminal of the obtained second identification information and the relaying apparatus.

Abstract: A spark plug having a connecting portion that electrically connects a center electrode with a metal terminal within an axial bore in an insulator. The connecting portion of the spark plug includes a resistor. A center electrode-side resistance, which is the resistance of a portion of the resistor that extends from the center thereof toward the center electrode in the axial direction, is larger than a metal terminal-side resistance, which is the resistance of a portion of the resistor that extends from the center thereof toward the metal terminal.

Abstract: A transfer unit transfers a message between a network and an external terminal. An input unit inputs a user ID for identifying a user. A generating unit generates a registration message requesting a registration of address information of the user. A transmitting unit transmits the registration message to a server. A receiving unit receives a response message including registration information and connection information from the server. When the connection information indicates a permission of a connection of the external terminal to the network, a control unit controls the transfer unit to transfer the message between the network and the external terminal.

Abstract: A spark plug having an insulator that can be restrained from cracking in an environment of heating and cooling cycles. The spark plug includes an insulator having an axial bore extending in the direction of the axis, and a center electrode held in one end portion of the axial bore. The center electrode has an outer layer, and a core provided within the outer layer and formed from a material higher in thermal conductivity than the outer layer. After a heat treatment, the outer layer has a high-hardness region having a hardness of 190 Hv or higher and a thickness of 30 ?m to 200 ?m, and an element supply region having a thickness of 50 ?m or more.

Abstract: A spark plug including a center electrode and a ground electrode having a core portion and an outer layer covering the core portion, the core portion being formed from a material having a thermal conductivity higher than that of the outer layer. At least a portion in which thickness of the outer layer is 0.5 mm or less is present at a cross-section perpendicular to a direction in which the ground electrode is extended. Further, the composition of the electrode material forming the outer layer is as follows: Ni is 96 mass % or more, total of at least one kind selected from Y and rare earth elements is 0.05 mass % or more, Al is 0.5 mass % or less, and Si is 0.5 mass % or more and 1.5 mass % or less, where the total of Ni, Y, rare earth elements, Al, Si does not exceed 100 mass %.

Abstract: The transferring unit transfers a message received from a PC or a network to a designated destination address. The judging unit judges whether an authentication message including the identification information of the user and a grant message indicating that the user is authenticated are transferred. The identification information acquiring unit acquires the identification information from the transferred authentication message. The SIP message processing unit creates a registration message that includes the address information of the user having the acquired identification information and transmits the created registration message to the SIP server when the grant message is transferred.

Abstract: A spark plug includes at least one of a center electrode or a ground electrode that is produced by the steps of: mixing a matrix metal with carbon so that the carbon content of the resultant mixture is adjusted to 80 vol. % or less; subjecting the mixture to powder compacting or sintering, to thereby form a core; placing the core in a cup formed of nickel or a metal containing nickel as a main component; and subjecting the cup to cold working. The thus-produced electrode exhibits favorable thermal conductivity and good heat dissipation, by virtue of the small difference in thermal expansion coefficient between the core and an outer shell. The spark plug including the above electrode exhibits excellent durability.

Abstract: A spark plug is provided having at least one of a center electrode or a ground electrode. The electrode comprises: a core formed of a composite material containing a matrix metal, the matrix metal being copper or a metal containing copper as a main component, and carbon dispersed in the matrix metal in an amount of 10 to 80 vol. %, the carbon having a thermal conductivity higher than that of the matrix metal. The electrode also contains an outer shell which surrounds the core and which is formed of nickel or a metal containing nickel as a main component. The thus-produced electrode exhibits favorable thermal conductivity and good heat dissipation, by virtue of the small difference in thermal expansion coefficient between the core and an outer shell. The spark plug including the above electrode exhibits excellent durability.

Abstract: A spark plug including a center electrode and a ground electrode having a gap between the center electrode and the ground electrode, the ground electrode has an outer layer which is formed from an Ni-based alloy and a core portion which is covered by the outer layer and formed from a material having a thermal conductivity higher than that of the outer layer. Further, the melting point of the Ni-based alloy forming the outer layer is 1150° C. or more and 1350° C. or less.

Abstract: A spark plug includes a ceramic insulator, a center electrode, a metallic shell, and a ground electrode. The center electrode has a shoulder portion at a forward end portion, which tapers forward with respect to the axial direction. A noble metal tip is joined to the forward end portion of the center electrode through a fusion zone. A spark discharge gap is formed between the noble metal tip and the ground electrode. The shortest distance between the fusion zone and a forward end surface of the noble metal tip is 0.8-1.2 mm. The outside diameter of the fusion zone as measured at a forward end of the fusion zone is smaller than that as measured at a rear end of the fusion zone. An acute angle ?1 formed by a straight line L1 and a straight line L2 satisfies the relational expression ?1?72°.

Abstract: A switching equipment stores identification information of communication established with respect to an infrastructure network system in a storage unit, and when an access request is received from a terminal device, the switching equipment adds the stored identification information to the access request and transfers the access request to a 1× Radius server. When the terminal device having requested the access is authenticated, the 1× Radius server notifies a PANA PAA of address information of the terminal device associated with the identification information added to the access request. The PANA PAA approves the same network access as the switching equipment with respect to the terminal device in the received address information.

Abstract: The storage unit stores therein authentication IDs that are used for authentication of users and address information in association with one another. The authentication processing unit receives from a PC an authentication message that includes an authentication ID and is used for the authentication of the user of a communication terminal, and performs authentication on the user based on the received authentication message. The SIP address acquiring unit acquires from the storage unit address information that corresponds to the authentication ID included in the authentication message when the user is authenticated. The SIP address registering unit sends the SIP location server a registration request for registering the acquired address information as the address information of the user of the IP telephone terminal associated with the PC that transmits the authentication message.

Abstract: A spark plug having a connecting portion that electrically connects a center electrode with a metal terminal within an axial bore in an insulator. The connecting portion of the spark plug includes a resistor. A center electrode-side resistance, which is the resistance of a portion of the resistor that extends from the center thereof toward the center electrode in the axial direction, is larger than a metal terminal-side resistance, which is the resistance of a portion of the resistor that extends from the center thereof toward the metal terminal.

Abstract: A spark plug includes a ceramic insulator having an axial hole formed in an axis direction of the spark plug, a center electrode inserted in a front side of the axial hole, a metal shell disposed around the ceramic insulator and a ground electrode joined to a front end portion of the metal shell, wherein the ground electrode has a cross-sectional area of 2.0 mm2 or smaller in any arbitrary cross section thereof taken in a direction perpendicular to a center line of the ground electrode; the ground electrode is made of a metal material containing 93 mass % or more of nickel; and the ground electrode has a Vickers hardness of 130 to 260 Hv.

Abstract: Provided is a spark plug which allows a predetermined resistance to be imparted to a resistor with restraint of variation in resistance of the resistor and in turn, enables enhancement of yield. The spark plug includes a ceramic insulator having an axial hole extending in the direction of an axis CL1, a center electrode, and a terminal electrode. A resistor is provided in the axial hole through sintering of a resistor composition which contains a conductive material such as carbon black, glass powder, and ceramic particles other than glass. As viewed on a section of the resistor taken along a direction orthogonal to the axis CL1, 50% or more of sintered glass powder formed through sintering of the glass powder has a circularity of 0.8 or greater.

Abstract: A spark plug is provided having at least one of a center electrode or a ground electrode. The electrode comprises: a core formed of a composite material containing a matrix metal, the matrix metal being copper or a metal containing copper as a main component, and carbon dispersed in the matrix metal in an amount of 10 to 80 vol. %, the carbon having a thermal conductivity higher than that of the matrix metal. The electrode also contains an outer shell which surrounds the core and which is formed of nickel or a metal containing nickel as a main component. The thus-produced electrode exhibits favorable thermal conductivity and good heat dissipation, by virtue of the small difference in thermal expansion coefficient-between the core and an outer shell. The spark plug including the above electrode exhibits excellent durability.

Abstract: A spark plug includes at least one of a center electrode or a ground electrode that is produced by the steps of: mixing a matrix metal with carbon so that the carbon content of the resultant mixture is adjusted to 80 vol. % or less; subjecting the mixture to powder compacting or sintering, to thereby form a core; placing the core in a cup formed of nickel or a metal containing nickel as a main component; and subjecting the cup to cold working. The thus-produced electrode exhibits favorable thermal conductivity and good heat dissipation, by virtue of the small difference in thermal expansion coefficient between the core and an outer shell. The spark plug including the above electrode exhibits excellent durability.

Abstract: A spark plug includes a ceramic insulator, a center electrode, a metallic shell, and a ground electrode. The center electrode has a shoulder portion at a forward end portion, which tapers forward with respect to the axial direction. A noble metal tip is joined to the forward end portion of the center electrode through a fusion zone. A spark discharge gap is formed between the noble metal tip and the ground electrode. The shortest distance between the fusion zone and a forward end surface of the noble metal tip is 0.8-1.2 mm. The outside diameter of the fusion zone as measured at a forward end of the fusion zone is smaller than that as measured at a rear end of the fusion zone. An acute angle ?1 formed by a straight line L1 and a straight line L2 satisfies the relational expression ?1?72°.