Pressure measuring glow plug
AssigneeRobert Bosch GmbH
InventorsJanpeter Wolff, Wolfgang Koetzle, Holger Scholzen
Life of this patent
Estimating the term…
Abstract
A pressure measuring glow plug includes: a housing in which a heating pin for igniting a combustion mixture of an internal combustion engine and a pressure measuring unit for recording a combustion chamber pressure of the internal combustion engine are situated. The heating pin has a glow current contact for an electric heating element. At the end of the heating pin facing away from the combustion chamber, a pressure transmitting element is fastened, which transmits the combustion chamber pressure acting on the heating pin to the pressure measuring unit. The pressure transmitting element is sleeve-shaped and forms an accommodation space for the glow current contact of the heating element.
Claims10
A pressure measuring glow plug comprising:
- a sleeve;
- a support element attached to the sleeve;
- a heating pin that is configured to ignite a combustion mixture of an internal combustion engine and that includes a heating pin housing that is at least partially within the sleeve, a heating element inside the heating pin housing, and a glow current contact, wherein:
- in a direction extending away from the internal combustion engine, the glow current contact extends from inside the heating pin housing to beyond an end of the heating pin housing, so that a distal end of the glow current contact, which is within the sleeve, is outside of the heating pin housing;
- and
- the glow current contact is configured to power the heating element at a proximal end of the glow current contact;
- a pressure sensor arranged within the sleeve and between the distal end of the glow current contact and a first side of the support element that faces toward the internal combustion engine;
- a flexible diaphragm attached to the sleeve and attached to the heating pin housing, the heating pin being axially displaceable within the sleeve, under a pressure of the internal combustion engine, by flexure of the flexible diaphragm, wherein the pressure sensor is configured to sense a pressure applied by the heating pin against the pressure sensor due to the axial displacement of the heating pin within the sleeve;
- and
- a glow current line that (a) at a connection point inside the sleeve, is connected to the glow current contact, (b) extends axially away from the connection point and into and through a first cutout in the support element to beyond a second side of the support element that faces away from the internal combustion engine, passing around the pressure sensor, so that at least a portion of the glow current line is arranged, in a radial direction, between the pressure sensor and the sleeve, and (c) downstream of the support element, with respect to the direction extending away from the internal combustion engine, is configured to electrically connect to a current terminal.
Dependencies are inferred from the claim text.