PISTON, BLOCK ASSEMBLY, AND METHOD FOR COOLING
20240011451 ยท 2024-01-11
Inventors
Cpc classification
F02F3/28
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
Abstract
A piston can include a skirt, a crown, and a cooling gallery. The skirt can have an upper body portion. The crown can be formed at the upper body portion. A wall can be formed underneath the crown so as to define a cooling gallery within the piston. The cooling gallery includes cooling gallery peripheral portion and a cooling gallery central portion. The cooling gallery can be configured to receive and to retain an amount of cooling fluid and to cause movement thereof within the cooling gallery between a cooling gallery peripheral portion and a cooling gallery central portion as the piston travels between top dead center and bottom dead center so as to cool both the piston outer region and the piston center region.
Claims
1. A piston having a piston outer region and a piston center region, the piston comprising: a skirt having an upper body portion; a crown formed at the upper body portion; and a wall formed underneath the crown so as to define a cooling gallery within the piston, the cooling gallery having cooling gallery peripheral portion and a cooling gallery central portion, the cooling gallery configured to receive and to retain an amount of cooling fluid such that the wall directs movement of the cooling fluid within the cooling gallery between the cooling gallery peripheral portion and the cooling gallery central portion as the piston travels between top dead center and bottom dead center so as to cool both the piston outer region and the piston center region.
2. The piston of claim 1, wherein the wall continuously extends circumferentially within the piston such that the cooling gallery is a single continuous volume.
3. The piston of claim 1, wherein when the amount of cooling fluid moves toward at least one of the cooling gallery central portion and the cooling gallery peripheral portion, the wall directs the amount of cooling fluid to swirl.
4. The piston of claim 3, wherein the wall includes at a ridge positioned proximate to the cooling gallery central portion and a ceiling of the wall, the ridge protruding inwardly from the wall such that the wall is configured to direct the amount of cooling fluid to swirl by altering movement of the amount of cooling fluid along the wall at the ridge.
5. The piston of claim 1, wherein the wall includes a sloped floor portion, a sloped ceiling portion, the cooling gallery central portion, and the cooling gallery peripheral portion, and wherein both the cooling gallery central portion and the cooling gallery peripheral portion extend between the sloped floor portion and the sloped ceiling portion.
6. The piston of claim 1, wherein the wall further includes a ceiling portion, and wherein the wall directs the amount of cooling fluid to move toward the cooling gallery peripheral portion when the cooling fluid travels along the ceiling portion of the wall in the direction from the piston center region to the piston outer region, and wherein the wall directs the amount of cooling fluid to move toward the cooling gallery central portion when the cooling fluid travels along a floor portion of the wall in the direction from the piston outer region to the piston center region.
7. The piston claim 1, wherein the piston further includes at least one piston ring groove and the skirt further includes an outer surface, and wherein the piston ring groove is formed in the outer surface and the cooling gallery peripheral portion is positioned proximate to the piston ring groove.
8. The piston of any claim 1, wherein a bowl of the piston is axisymmetric about a central longitudinal axis of the piston.
9. The piston of claim 1, wherein the cooling gallery central portion and the cooling gallery peripheral portion are concave.
10. The piston of claim 1, wherein the wall includes a ridge protruding partially into the cooling gallery from the wall.
11. A block assembly, comprising: at least one cylinder; and a piston configured to reciprocate within the at least one cylinder, the piston having a piston outer region and a piston center region, the piston comprising: a skirt having an upper body portion; a crown formed at the upper body portion; and a wall formed underneath the crown so as to define a cooling gallery within the piston, the cooling gallery having cooling gallery peripheral portion and a cooling gallery central portion, the cooling gallery configured to receive and to retain an amount of cooling fluid such that the wall directs movement of the cooling fluid within the cooling gallery between the cooling gallery peripheral portion and the cooling gallery central portion as the piston travels between top dead center and bottom dead center so as to cool both the piston outer region and the piston center region.
12. The block assembly of claim 11, further comprising at least one of: a crankshaft that is operatively connected to the piston so as to facilitate movement of the piston from top dead center to bottom dead center and from bottom dead center to top dead center; and a fuel injector that is configured to receive fuel from a fuel source and to spray the fuel into the at least one cylinder for combustion within the at least one cylinder.
13. The block assembly of claim 11, wherein the wall directs the amount of cooling fluid to move toward the cooling gallery peripheral portion when the piston is approaching top dead center, and wherein the wall directs the amount of cooling fluid to move toward the cooling gallery central portion when the piston is approaching bottom dead center.
14. The block assembly of claim 11, wherein the wall includes a sloped floor portion, a sloped ceiling portion, the cooling gallery central portion, and the cooling gallery peripheral portion, and wherein both the cooling gallery central portion and the cooling gallery peripheral portion extend between the sloped floor portion and the sloped ceiling portion.
15. The block assembly of claim 11, the wall is configured to swirl the amount of cooling fluid as the amount of cooling fluid flows toward at least one of the cooling gallery central portion and the cooling gallery peripheral portion.
16. The block assembly of claim 11, wherein the wall includes at least one ridge that protrudes inwardly from the wall of the cooling gallery thereby causing the amount of cooling fluid to swirl, the at least one ridge including a first ridge that is positioned proximate to one of the cooling gallery central portion and the cooling gallery outer portion.
17. A method of cooling a piston, the method comprising: receiving and retaining an amount of cooling fluid within a cooling gallery; directing, as the piston travels toward top dead center, the amount of cooling fluid to move within the cooling gallery toward one of a cooling gallery central portion so as to cool a piston center region and a cooling gallery peripheral portion so as to cool a piston outer region; and directing, as the piston travels toward bottom dead center, the amount of cooling fluid to move within the cooling gallery toward the other of the cooling gallery central portion so as to cool the piston center region and the cooling gallery peripheral portion so as to cool the piston outer region.
18. The method of claim 17, further comprising swirling the amount of cooling fluid when the amount of cooling fluid moves into the cooling gallery central portion or the cooling gallery peripheral portion by causing the amount of cooling fluid to move toward at least one ridge extending radially inward from a wall of the cooling gallery.
19. The method of claim 18, wherein swirling the amount of cooling fluid occurs when the amount of cooling fluid moves into the cooling gallery central portion.
20. The method of any one claim 17, wherein directing, as the piston travels toward top dead center, the amount of cooling fluid to move within the cooling gallery toward one of the cooling gallery central portion so as to cool the piston center region and the cooling gallery peripheral portion so as to cool the piston outer region comprises moving the amount of cooling fluid toward the cooling gallery central portion as the piston travels toward bottom dead center; and wherein directing, as the piston travels toward bottom dead center, the amount of cooling fluid to move within the cooling gallery toward the other of the cooling gallery central portion so as to cool the piston center region and the cooling gallery peripheral portion so as to cool the piston outer region includes moving the amount of cooling fluid toward the cooling gallery peripheral portion as the piston travels toward top dead center.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The above-mentioned and other features of this disclosure and the manner of obtaining them will become more apparent and the disclosure itself will be better understood by reference to the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings, wherein;
[0013]
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[0015]
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[0018]
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[0020]
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[0023]
[0024] Although the drawings represent embodiments of the various features and components according to the present disclosure, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate and explain the present disclosure. The exemplification set out herein illustrates embodiments of the disclosure, and such exemplifications are not to be construed as limiting the scope of the disclosure in any manner.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE DISCLOSURE
[0025] For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings, which are described below. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. The disclosure includes any alterations and further modifications in the illustrated device and described methods and further applications of the principles of the disclosure, which would normally occur to one skilled in the art to which the disclosure relates. Moreover, the embodiments were selected for description to enable one of ordinary skill in the art to practice the disclosure.
[0026]
[0027] As described in further detail below, the piston 100 can be configured to reciprocate within the at least one cylinder 5 during engine operation. As a general introduction with relation to the engine 1 and its components, movement of the piston 100 relative to the cylinder 5 can correspond to movement of a crankshaft 9 of the engine 1. The crankshaft 9 is movably received within the block assembly 7 and operatively connected to the piston 100 such that rotation of the crankshaft 9 causes translation of the piston 100 within the cylinder 5. In this regard, the block assembly 7 can include a crankshaft 9 that is operatively connected to the piston 100 so as to facilitate movement of the piston 100 from top dead center to bottom dead center and from bottom dead center to top dead center. In addition, or in alternative, the block assembly 7 can include a fuel injector 10 that is configured to receive fuel from a fuel source 11 and to spray the fuel into the at least one cylinder 5 for use in combustion within the at least one cylinder 5.
[0028] In operation, the engine 1 can perform one or more combustion cycles that cause the piston 100 to reciprocate within the cylinder 5. For instance, during an engine operation, a fuel injector 10 provides (directly or indirectly) controlled injections of fuel into the piston 100 (e.g., at a piston bowl), which, in a compression-ignition engine, results in combustion that is contained within a combustion chamber when the piston 100 is at or near TDC. This combustion at or near TDC then forces the piston 100 to move toward BDC. In continued operation, the piston 100 cyclically reciprocates between TDC and BDC in this manner at varying rates depending on user demand. This cyclic combustion heats the piston 100 and/or movement generates heat within the piston 100 either or both of which is then cooled by cooling fluid retained within the cooling gallery 110. By designing the cooling gallery 110, for example, to optimize the shape of cooling gallery 110 considering the reciprocal movement of the piston 100 within a cylinder 5 as described herein, cooling efficiency of the piston 100 may be increased.
[0029] To this end,
[0030] As illustrated between these figures, the piston 100 includes a skirt 16 having an upper body portion 32, a crown 14 formed at the upper body portion 32, and a cooling gallery 110 formed via one or more voids underneath the crown 14 and in fluid communication with the at least one cylinder 5. In effect, the cooling gallery 110 is defined by wall portions (e.g., some or all of the wall 114) of the piston such that the cooling gallery is an internal volume or void formed within the piston 100. The cooling gallery 110 is thereby configured to receive and to retain an amount of cooling fluid. As described in further detail below, the wall 114 that defines the cooling gallery 110 can be configured to direct, cause, or otherwise facilitate movement of the cooling fluid within the cooling gallery 110 between a cooling gallery peripheral portion 111 and a cooling gallery central portion 112 as the piston 100 travels between TDC and BDC so as to cool both the piston outer region 101 and the piston center region 102.
[0031] In examples, the cooling gallery 110 can be a single continuous volume that is defined by the wall 114 of the piston. For instance, in examples the wall 114 continuously extends circumferentially within the piston 100 such that the cooling gallery 110 is a single continuous volume. During operation, the wall 114 of the piston 100 directs movement of cooling fluid within the cooling gallery 110 between a cooling gallery peripheral portion 111 and a cooling gallery central portion 112 as the piston 100 travels between and arrives at TDC and BDC. In this manner, the cooling gallery 110 facilitates cooling both of a piston outer region 101 and a piston center region 102. In addition to circumferential movement within the cooling gallery 110, having a cooling gallery 110 that is a single continuous volume promotes movement of the amount of cooling fluid throughout the cooling gallery 110. This phenomenon occurs at least because the cooling gallery peripheral portion 111 and the cooling gallery central portion 112 are in fluid communication with each other throughout operation. Alternatively, similar results can be achieved by a cooling gallery 110 having a plurality of continuous volumes, such as discrete volumes spaced circumferentially and/or radially about the piston 100.
[0032] The wall 114 of the piston can include a number of sloped and curved portions that define the cooling gallery 110. As illustrated, the cooling gallery 110 includes a wall 114 that has floor portions 115 and ceiling portions 116. For instance, in this regard, the wall 114 can direct the amount of cooling fluid to move toward the cooling gallery peripheral portion 111 when the cooling fluid travels along the ceiling portion 116 of the wall 114 in the direction from the piston center region 102 to the piston outer region 101. Moreover, the wall 114 can direct the amount of cooling fluid to move toward the cooling gallery central portion 112 when the cooling fluid travels along a floor portion 115 of the wall 114 in the direction from the piston outer region 101 to the piston center region 102.
[0033] In particular, the wall 114 as shown has a sloped floor portion 115, a sloped ceiling portion 116, the cooling gallery central portion 112, and the cooling gallery peripheral portion 111. Both the cooling gallery central portion 112 and the cooling gallery peripheral portion 111 extend between the sloped floor portion 115 and the sloped ceiling portion 116. To promote swirling the cooling fluid, for example, either or both of the cooling gallery central portion 112 and the cooling gallery peripheral portion 111 are curved. As such, as shown the cooling gallery central portion 112 and the cooling gallery peripheral portion 111 can be generally concave toward the sloped floor portion 115 and the sloped ceiling portion 116. In examples, the cooling gallery peripheral portion 111 can be positioned proximate the piston outer region 101, and the cooling gallery central portion 112 can be positioned proximate to the piston center region 102. As such, the cooling gallery peripheral portion 111 can be proximate to at least one piston ring groove 106 at an outer surface 104 of the skirt 16, and the cooling gallery central portion 112 can be proximate to a center of the bowl 26. In this manner, movement of the cooling fluid at the cooling gallery peripheral portion 111 cools the piston outer region 101, and movement of the cooling fluid at the cooling gallery central portion 112 cools the piston center region 102.
[0034] One or more slope angles can define the cooling gallery 110 sloped ceiling portion 116 and sloped floor portion 115 relative to the longitudinal axis 12 of the piston 100. As shown, both the sloped ceiling portion 116 and the sloped floor portion 115 slope downwardly from the cooling gallery peripheral portion 111 to the cooling gallery central portion 112. As well, the slope angle of the sloped ceiling portion 116 is different from the slope angle of the sloped floor portion 115. Of course, it is not beyond the scope of this disclosure for the slope angle for either or both of the cooling gallery peripheral portion 111 and the cooling gallery central portion 112 to be more or less than shown, in a different direction than shown, or to be the same magnitude rather than different magnitudes. For instance, certain cooling galleries 110 can have only a sloped floor portion 115 or a sloped ceiling portion 116. Likewise, certain cooling galleries 110 can have only one curved cooling gallery central portion 112 or cooling gallery peripheral portion 111.
[0035] In examples, an obstruction (e.g., a recess or protrusion) in the wall 114 of the cooling gallery can direct the amount of cooling fluid to swirl at certain portions within the cooling gallery 110. For instance, the wall 114 can swirl the amount of cooling fluid as it flows toward at least one of the cooling gallery central portion 112 and the cooling gallery peripheral portion 111. As illustrated, the wall 114 includes at least one ridge 120 protruding inwardly from the wall 114 that defines the cooling gallery 110. In this regard, the wall 114 can thereby direct the amount of cooling fluid to swirl by altering movement of the amount of cooling fluid along the wall 114 at the at least one ridge. Size, shape, and location of the ridge 120 may vary between examples.
[0036] With continued reference to
[0037] The wall may include multiple ridges 120 spaced about the cooling gallery 110. Circumferential spacing, radial spacing, or both can define a plurality of ridges 120 within the cooling gallery 110. In examples, a first ridge of the at least one ridge 120 can be positioned proximate to the cooling gallery central portion 112. A second ridge can, for example, be proximate the cooling gallery peripheral portion 111. In examples, the first ridge is positioned at a sloped ceiling portion 116 of the cooling gallery 110 but can be positioned at the sloped floor portion 115 of the cooling gallery 110 in other examples. In examples, the second ridge can be positioned on the same or other of the sloped floor portion 115 and the sloped ceiling portion 116 as the first ridge.
[0038]
[0039] The four illustrated stages of operation generally cover one cycle of the piston 100 moving within a respective cylinder. In examples, the wall direct the amount of cooling fluid 301 to move toward the cooling gallery peripheral portion 111 when the piston 100 is approaching TDC, and the wall directs the amount of cooling fluid 301 to move toward the cooling gallery central portion 112 when the piston 100 is approaching BDC. Beginning with the first stage shown in
[0040]
[0041] In more detail regarding the contour plots, Detail A shows heat transfer coefficient contour plots for the outer and inner galleries 34, 36 of a known piston for comparison purposes to Detail B. In particular, Detail B shows heat transfer coefficient contour plots for piston cooling galleries similar to those discussed herein, including the cooling gallery 110 discussed in relation to
[0042] According to principles of the present disclosure, as shown in
[0043] In examples, the method 600 can include, at step 609, swirling the amount of cooling fluid when the amount of cooling fluid moves into the cooling gallery central portion or the cooling gallery peripheral portion. In examples, swirling the amount of cooling fluid can include causing the amount of cooling fluid to move toward at least one ridge extending radially inward from a wall of the cooling gallery. In examples, swirling the amount of cooling fluid can occur when the amount of cooling fluid moves into the cooling gallery central portion. In examples, the amount of cooling fluid can move toward the cooling gallery central portion as the piston travels toward BDC, and the amount of cooling fluid can move toward the cooling gallery peripheral portion as the piston travels toward TDC. In this regard, directing, as the piston travels toward top dead center, the amount of cooling fluid to move within the cooling gallery toward one of a cooling gallery central portion so as to cool the piston center region and the cooling gallery peripheral portion so as to cool a piston outer region at step 605 can include moving the amount of cooling fluid toward the cooling gallery central portion as the piston travels toward bottom dead center. Moreover, directing, as the piston travels toward bottom dead center, the amount of cooling fluid to move within the cooling gallery toward the other of the cooling gallery central portion so as to cool the piston center region and the cooling gallery peripheral portion so as to cool the piston outer region at step 607 can include moving the amount of cooling fluid toward the cooling gallery peripheral portion as the piston travels toward top dead center.
[0044] The connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements. The scope is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean one and only one unless explicitly so stated, but rather one or more. Moreover, where a phrase similar to at least one of A, B, or C is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B or C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C.
[0045] In the detailed description herein, references to one embodiment, an embodiment, an example embodiment, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art with the benefit of the present disclosure to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments.
[0046] Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f), unless the element is expressly recited using the phrase means for. As used herein, the terms comprises, comprising, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus
[0047] While the embodiments have been described as having exemplary designs, the present disclosure may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.