Abstract:
A spark plug (20) for being threaded into a cylinder head (28) includes a shell (24) with threads (26) disposed at a predetermined angled relative to the ground electrode (34). The position of the threads (26) relative to the ground electrode (34) places the ground electrode (34) in a predetermined position in the combustion chamber (22) and relative to components of the engine, thus allowing the ground electrode (34) to provide a robust and reliable ignition. The threads (26) are formed by a thread forming apparatus (102) that includes an orientation tool (38) to position the ground electrode (34) relative to a thread forming apparatus (102), allowing the thread forming apparatus (102) to form the threads (26) at the desired angle (α).
Abstract:
A spark ignition device, metal shell, and methods of construction are provided. The spark ignition device has a ceramic insulator extending along a longitudinal axis and a metal shell. The metal shell extends along the longitudinal axis to a distal end. A center electrode is received in the ceramic insulator and extends along the longitudinal axis. A ground electrode has an attachment end fixed by a weld joint to the distal end of the shell and a free end extending from the distal end to provide a spark gap. The weld joint includes a resistance weld joint and a laser weld joint, which in combination inhibit material expulsion; provide a reliable, strong attachment of the ground electrode to the shell; provide an improved heat transfer path between the ground electrode and the shell, and facilitate repeatable and accurate positioning of the ground electrode to the shell.
Abstract:
A corona igniter 20 includes an electrode gap 28 between the central electrode 22 and the insulator 32 and a shell gap 30 between the insulator 32 and the shell 36. An electrically conductive coating 40 is disposed on the insulator 32 along the gaps 28, 30 to prevent corona discharge 24 in the gaps 28, 30 and to concentrate the energy at a firing tip 58 of the central electrode 22. The electrically conductive coating 40 is disposed on an insulator inner surface 64 and is spaced radially from the electrode 22. The electrically conductive coating 40 is also disposed on the insulator outer surface 72 and is spaced radially from the shell 36. During operation of the igniter 20, the electrically conductive coating 40 provides a reduced voltage drop across the gaps 28, 30 and a reduced electric field spike at the gaps 28, 30.
Abstract:
A corona igniter assembly 20 comprises an ignition coil assembly 22, a firing end assembly 24, and a metal tube 26 connecting the ignition coil assembly 22 to the firing end assembly 24. A rubber boot 28 is disposed in the metal tube 26 and compressed symmetrically between a coil output member 30 of the ignition coil assembly 22 and an insulator 42 of the firing end assembly 24. Thus, the rubber boot 28 fills any air gaps and provides a hermetic seal between the ignition coil assembly 22 and the firing end assembly 24 to prevent unwanted corona discharge from forming from those air gaps.
Abstract:
A corona igniter comprises an electrode with a central extended member extending along a central axis and a crown extending radially outwardly from the central extended member. The central extended member has an extended length and the crown has a crown length. The extended length is greater than the crown length such that the extended member approaches a piston more closely than the crown. In addition, the firing tips of the crown each present a first spherical radius which is less than a second spherical radius of the central extended member. Thus, if arcing occurs, it forms from the central extended member, rather than from the crown. Accordingly, the firing tips of the crown experience less wear and remain sharp. In addition, due to the sizes of the spherical radii, corona discharge is more likely to form from the firing tips than from the central extended member.
Abstract:
A spark ignition device, ground electrode therefor, and methods of construction thereof are provided. The spark ignition device includes a generally annular ceramic insulator with a metal shell surrounding at least a portion of the ceramic insulator. A center electrode is received at least in part in the ceramic insulator and a ground electrode extends from the shell to a free end portion. A firing tip is attached adjacent the free end portion of the ground electrode to provide a spark gap between the center electrode and the firing tip. The free end portion is at least partially bounded by at least one “as laser cut” peripheral side extending adjacent the firing tip.
Abstract:
A spark plug assembly has a ceramic insulator with a metal outer shell surrounding at least a portion of the insulator. A ground electrode is operatively attached to the outer shell and a center electrode having an elongate body extends through the insulator. The center electrode and the ground electrode provide a spark gap. A force sensor is received about the insulator. An annular inner shell is received between the outer shell and the insulator, wherein the inner shell has a surface configured to confront the insulator along an axial direction.
Abstract:
A spark plug assembly includes an insulator having an upper shoulder and a lower shoulder and a metal annular outer shell having an outer surface and a cavity bounded by an inner surface. The inner surface has a flange extending inwardly to confront the lower shoulder of the insulator. The outer shell has a proximal end and an opposite fastening end. The fastening end has an external threaded region and an annular sealing seat extending outwardly adjacent the flange. The outer shell has an annular shoulder extending radially between the sealing seat and the proximal end. The proximal end has a turnover axially confronting the upper shoulder of the insulator. A sensor assembly is received about the outer shell between the shoulder of the shell and the turnover. The sensor assembly is responsive to send a signal in response to relative axial movement between the insulator and the outer shell.
Abstract:
A spark plug includes an electrode tip assembly located at an axially-facing free end surface of an electrode body. The electrode tip assembly includes an electrode tip body and a firing tip and has a longitudinal axis that is generally perpendicular to a longitudinal axis of the electrode body. The electrode tip body may be a Ni-alloy piece and is attached to the electrode body, and the firing tip may be an Ir-alloy piece with a sparking surface that faces a spark gap. The electrode body may include a groove formed in the axially-facing free end surface that is useful to help position the electrode tip assembly for attachment. The spark gap can be formed between opposing electrode tip assemblies, and the size of the spark gap can be adjusted during assembly without the need for bending the electrode body.
Abstract:
A molded lamp socket. The molded lamp socket includes a lamp base body molded from a first plastic material providing a socket cavity with an opening for receiving a lamp bulb. The molded lamp socket also includes a lead extending from a first contact portion disposed in the socket cavity to a second contact portion spaced from the socket cavity. The molded lamp socket also includes a mounting body molded from a second plastic material providing a plug cavity encircling the second contact portion. The mounting body is overmolded with respect to the lamp base body.