Patent Application
20170342956
The present disclosure relates to a laser ignition plug with multiple ignition points for an internal combustion engine.
This section provides background information related to the present disclosure which is not necessarily prior art.
Internal combustion engines typically include a combustion chamber, intake and exhaust ports, a compression device, a fuel delivery system, and an ignition device. A combustible mixture of air and fuel flows into the combustion chamber through the intake port and is ignited by the ignition device. The ignition device may be a laser ignition plug that emits focused laser light into the combustion chamber to produce flame kernel and ignite the mixture of air and fuel. Conventional laser ignition plugs, however, emit a single laser pulse to ignite the mixture of air and fuel and are subject to improvement.
This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.
The present teachings are directed to an ignition device for an internal combustion engine. The ignition device includes a plurality of optical focusing lenses, including a center optical focusing lens and at least one satellite optical focusing lens. The center optical focusing lens is configured to focus laser light from a laser generator to a center ignition point in a combustion chamber of a cylinder of the internal combustion engine. The at least one satellite optical focusing lens is configured to focus laser light from the laser generator to at least one satellite ignition point in the combustion chamber of the cylinder of the internal combustion engine. The at least one satellite optical focusing lens is directionally angled away from the center optical focusing lens. A firing depth of the center ignition point is greater than a firing depth of the at least one satellite ignition point.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
Example embodiments will now be described more fully with reference to the accompanying drawings.
The present teachings are directed toward a laser ignition plug that uses focused laser light to ignite a combustible air-fuel mixture within a combustion chamber of an internal combustion engine. As discussed in further detail below, the laser ignition plug uses multiple lasers to generate multiple ignition points at different firing projections and depths, resulting in enhanced ignitability. In internal combustion engines using highly diluted and lean burn combustion mixtures, ignitable pockets of the air-fuel mixture may be less prevalent than in traditional internal combustion engines that do not use highly diluted and lean burn combustion mixtures. As such, using a laser ignition plug with multiple lasers that generate multiple ignition points at different firing projections and depths can increase the combustion stability and performance, as well as the efficiency of the internal combustion engine.
With reference to
The laser ignition plug 12 is connected to a laser generator 16. The laser generator 16 can be a pulse laser generator configured to selectively emit pulses of laser light. The laser generator 16 emits laser light through optical fiber connections 18 to the laser ignition plug 12. While the sectional view of
The optical fiber connections 18 are received by a cover plate 20 of the laser ignition plug 12 and fed through the cover plate 20 to connect to collimating lens housings 22. The collimating lens housings 22 are each connected to optical lens support tubes 25, 26 positioned within a laser ignition plug housing 27 of the laser ignition plug 12. As discussed in further detail below, the optical lens support tubes 25, 26 include a center optical lens support tube 25 and multiple satellite optical lens support tubes 26. With reference to
With reference again to
As shown in
As shown in
L=L1+L2, where L1 is not equal to L2. (1)
Further, the firing depth L1 of the satellite ignition points 52 may be more than half of the firing depth L of the center ignition point 50.
As shown in
Because the satellite optical lens support tubes 26 are angled by the offset angle theta (θ) and the optical focusing lenses 32 are pointed towards the periphery of the laser ignition plug housing 27, the resulting satellite ignition points 52 can be located further away from the laser emitted by the center optical lens support tube 25, as compared with a configuration of satellite optical lens support tubes that are not angled and that are configured to be parallel with a vertical axis of the center optical lens support tube 25. With reference again to
With reference to
In this way, as shown in
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
