摘要:
There is provided a test method for detecting the presence or absence of a defect in a spark plug insulator, including a reference voltage determination process, a test area determination process, a test voltage determination process and a current detection process. In the reference voltage determination process, a reference voltage V F is determined. In the test area and voltage determined processes, test area and voltage are determined so as not to incur a flashover on the basis of a reference insulator of the same material, shape and size as the spark plug insulator when the reference insulator is placed in position between first and second test electrodes. In the current detection step, the test voltage is applied between the first and second test electrodes to detect an electric current between the first and second test electrodes.
摘要:
A spark plug (100) including a cylindrical insulator (10) having an axial hole (12) extending in an axial direction; a center electrode (20) held in the axial hole on a leading end side; a connecting terminal (40) held in the axial hole (12) on a trailing end side; and a sealing layer (80, 85) provided in the axial hole and including a glass sealing material containing a glass component and a metallic component, the sealing layer including a first sealing layer (80) containing a first glass sealing material and a second sealing layer containing a second glass sealing material laminated in an axial direction of the axial hole, the first sealing layer (80) contacting the center electrode, and the second sealing layer (85) contacting the connecting terminal (40), wherein the second glass sealing material has a fluidity higher than that of the first glass sealing material at a temperature higher than a softening point of a glass component in the sealing layer.
摘要:
A spark plug 100 with a built-in resistor comprises an insulator 2 having an axially extending passing-through-hole 6, a terminal metal fitting 13 fixed within the passing-through-hole 6 at an end thereof, a center electrode 3 fixed within the same passing-through-hole at the other end thereof and a resistor 15 provided between the terminal metal fitting 13 and the center electrode 3 within the passing-through-hole 6. A surface layer region including the surface of the center electrode 3 which is exposed (facing) to the resistor 15 is a metallic layer 30 formed of a metal based on at least one of Zn, Sn, Pb, Rh, Pd, Pt, Cu, Au, Sb and Ag or a Ni alloy containing at least one of B and P, so that the center electrode 3 is provided in direct contact with the resistor 15 on the surface of the metallic layer 30.
摘要:
An ignition plug (1) includes an insulator (2) having an axial hole (4) extending therethrough in the direction of an axial line (CL1), a center electrode (5) inserted into a forward end portion of the axial hole (4), and a metallic shell (3) disposed externally of the insulator (2). The insulator (2) includes a step portion (14) engaged with an inner circumferential portion of the metallic shell (3) and a leg portion (13) extending forward from the forward end of the step portion (14). The porosity of the leg portion (13) is 3.0% or less. Of three regions of the leg portion (13) obtained by radially trisecting it in a cross section perpendicular to the axial line (CL1), the outermost region is defined as a first region (AR1) and the innermost region is defined as a second region (AR2). The porosity of the first region (AR1) is equal to or more than 1.20 times the porosity of the second region (AR2).
摘要:
[Objective] To improve both load life performance and radio-noise-preventing property in a spark plug including a resistor containing a Ti component. [Means for Solution] A spark plug includes a circular columnar insulator (2) having a through hole (6), a center electrode (3), a terminal shell (13), and a resistor (15) which is provided in the through hole (6) and between the terminal shell (13) and the center electrode (3), and which contains glass, a Ti component, a Zr component, and a non-metallic electrically conductive material. In a cross section of a conduction path portion of the resistor(15), the conduction path portion containing the Zr component and the Ti component, the average of the Ti component contents by weight of five continuous circular regions, each region having a diameter of 20 µm, is 0.5 wt.% to 15 wt.%; and when A represents the average of the Ti component contents by weight of any 30 circular regions in the conduction path portion, and when B represents the Ti component content by weight of each of the 30 circular regions, the total of the number of circular regions in which B is less than 0.25 times A and the number of circular regions in which B is greater than 3.0 times A is 2 or less.
摘要:
[Objective] To improve both load life performance and radio-noise-preventing property in a spark plug including a resistor containing a Ti component. [Means for Solution] A spark plug includes a circular columnar insulator (2) having a through hole (6), a center electrode (3), a terminal shell (13), and a resistor (15) which is provided in the through hole (6) and between the terminal shell (13) and the center electrode (3), and which contains glass, a Ti component, a Zr component, and a non-metallic electrically conductive material. In a cross section of a conduction path portion of the resistor(15), the conduction path portion containing the Zr component and the Ti component, the average of the Ti component contents by weight of five continuous circular regions, each region having a diameter of 20 µm, is 0.5 wt.% to 15 wt.%; and when A represents the average of the Ti component contents by weight of any 30 circular regions in the conduction path portion, and when B represents the Ti component content by weight of each of the 30 circular regions, the total of the number of circular regions in which B is less than 0.25 times A and the number of circular regions in which B is greater than 3.0 times A is 2 or less.
摘要:
A method for manufacturing an insulator for a spark plug is provided. The method includes: a preparing step; a press pin arranging step; a powder filling step after the press pin arranging step; a cavity blocking step after the powder filling step; a compression molding step after the cavity blocking step; a die releasing step after the compression molding step; and a press pin removing step after the die releasing step.
摘要:
A method for manufacturing an insulator includes: preparing a press pin (50) and a forming die (80) having a cavity (83), the press pin (50) including a pin-side spiral portion (54) formed on a first position; filling a raw powder (GP) into the cavity (80); arranging the press pin (50) within the cavity (83); pressing the raw powder (GP) within the cavity (83) along with the press pin (50), and obtaining a green body (PC1) formed with a green body-side spiral portion; releasing the green body (PC1) along with the press pin (50) from the cavity (83); retreating the press pin (50) with respect to the green body (PC1) while rotating the press pin (50) relative to the green body (PC1) around an axis, and extracting the press pin (50) from the green body (PC1) ; and removing an unnecessary portion from the green body (PC1). The first position is positioned such that the green body-side spiral portion is located in the unnecessary portion of the green body (PC1).
摘要:
There is provided a test method for detecting the presence or absence of a defect in a spark plug insulator, including a reference voltage determination process, a test area determination process, a test voltage determination process and a current detection process. In the reference voltage determination process, a reference voltage V F is determined. In the test area and voltage determined processes, test area and voltage are determined so as not to incur a flashover on the basis of a reference insulator of the same material, shape and size as the spark plug insulator when the reference insulator is placed in position between first and second test electrodes. In the current detection step, the test voltage is applied between the first and second test electrodes to detect an electric current between the first and second test electrodes.