Abstract:
A dosing device (1) is provided that is suitable for administering a reagent (2) into an exhaust chamber (4) of an internal combustion engine. The device (1) comprises a nozzle body (6) and an insulating jacket (5) wherein the jacket (5) is mounted to the nozzle body (6) at one or more mounting points (8,9), and wherein the dosing device (1) is adapted to engage with a port (10) located in the wall of an exhaust chamber (4). The insulating jacket (5) defines a compartment (11), which can comprise an insulating material or can be substantially evacuated. The dosing device (1) of the invention is advantageously insulated from the elevated temperatures in the surrounding environment, thereby allowing for the reagent to be maintained at an optimal working temperature range.
Abstract:
The present invention relates an actuator arrangement for use in a fuel injector, comprising: a piezoelectric actuator having a body section, said body section having a first end piece and a second end piece; a sleeve which enshrouds at least part of the body section of the actuator; and at least one constrictive member, disposed externally with respect to the sleeve wherein the constrictive member applies a constrictive force to the sleeve to maintain a seal between the sleeve and the underlying body section of the actuator. The underlying body section comprises an alternation of smooth sections and rough sections; said rough sections comprising superficial markings.
Abstract:
A method of dosing a reagent into an exhaust gas stream of an internal combustion engine (3) having an SCR catalyst (13), the method comprising injecting reagent from a reagent tank (21) into the exhaust gas stream at a position upstream of the SCR catalyst (13) using a reagent injector (40) in accordance with a first dosing schedule in order to remediate a predetermined proportion of NOx in the exhaust gas stream, the first dosing schedule being associated with a first range of engine operating conditions; and injecting reagent from the reagent tank (21) into the exhaust gas stream at a position upstream of the SCR catalyst (13) using a reagent injector (40) in accordance with a second dosing schedule in order to enable heat transfer between the reagent injector (40) and said injected reagent, the second dosing schedule being associated with a second range of engine operating conditions. Dosing in accordance with said first or said second dosing schedule is carried out in dependence on whether engine operating conditions lie within said first or said second range of engine operating conditions, and the proportion of NOx in the exhaust gas stream which is remediated by dosing using said second dosing schedule is less than said predetermined portion. A reagent dosing system (1) is also provided for dosing a reagent into the exhaust gas stream of an internal combustion engine (3), comprising a reagent tank (21) for storing a supply of reagent, an injector module (40) comprising an atomising dispenser (42) and a positive-displacement metering pump (41) which draws reagent from the reagent tank (21) and delivers it to the dispenser (42) a supply line (35) coupling the reagent tank (21) to the injector module (40), and a dosing control unit (70) operable to control the injector module (40) to inject reagent into the exhaust gas stream. A priming pump (80) is provided to urge reagent along the supply line (35) toward the injector module (40) under selected conditions.
Abstract:
Apparatus is disclosed that is suitable for connecting first and second electrical connection points arranged at different angular orientations, for example in a fuel injector having a pressure sensor integrated into a cap nut. The apparatus comprises a generally cylindrical first body (118) having a first electrical connection point (B), a generally tubular second body (122) attachable to an end region (120) of the first body (118) and having a second electrical connection point (136), a first annular conductor (152) associated with the first body (118) and connected to the first connection point (B), and a second annular conductor (164) associated with the second body (122) and connected to the second connection point (136). The first and second connection points (B, 136) are located laterally from a common axis (A) of the first and second bodies (118, 122) and, when the second body (122) is attached to the first body (118), the first and second annular conductors (152, 164) are in electrical contact so as to connect the first connection point to the second connection point (136) irrespective of whether the first and second connection points are in alignment in a direction parallel to the common axis (A).
Abstract:
The invention concerns an encapsulated actuator as well as a method of encapsulating an actuator/stack in an encapsulation member, which comprising at least an innermost heat shrinkable, polymeric sleeve member and an overlaying outermost, heat shrinkable, polymeric sleeve member. The sleeve members have each a different shrinkage temperature, wherein the shrinkage temperature of the outermost sleeve member is higher than the shrinkage temperature of the innermost sleeve member. The method comprising essentially the following steps: a. Arranging the stack inside the innermost sleeve member, b. Arranging the outermost sleeve member so as to overlay the innermost sleeve member(s), c. Placing the stack under vacuum so as to degas it, d. Heating the stack above the shrinkage temperature of the outermost sleeve member so as to shrink the outermost sleeve member, e. Placing the stack under atmospheric pressure f. Cooling the stack.
Abstract:
An injector (56) for a fuel injection system comprising: input means (51a,51b) for receiving drive signals from an injector drive circuit for controlling operation of the injector, and; an ID chip (62) wherein the injector further comprises an electronic latch means (68) arranged such that (i) in response to a first condition, the electronic latch means is arranged to be enabled such that the ID chip is in communication with the injector drive circuit via the input means, and; (ii) in response to a second condition, the electronic latch means is arranged to be disabled such that the ID chip is not in communication with the injector drive circuit via the input means.