Piston head and piston head assembly

Abstract

To provide a piston head and a piston head assembly.SOLUTION: A piston head includes an upper portion including an upper wall, an outer wall extending around a periphery of the upper wall, and an inner wall disposed at the radial inner side of the outer wall. A cooling passage is defined between the outer wall and the inner wall. The piston head further includes a lower potion extending downward from the upper portion. The lower portion includes an upper surface and a skirt extending from the upper surface in a direction away from the upper portion. The skirt defines a pin hole which receives the pin. The pin hole is centered on a pin hole center axis. A part of the skirt between the pin hole center axis and a skirt reference axis has a vertical profile which is substantially non-linear. The skirt reference axis is orthogonal to the pin hole center axis and parallel to the upper surface.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This application generally relates to a piston head for use in a combustion cylinder.

Background Art

[0002] An internal combustion engine burns a mixture of fuel (e.g., diesel, gasoline, natural gas, etc.) and air in a combustion chamber. The combustion of the air-fuel mixture moves the piston, which in turn generates power (e.g., to move a vehicle, to power a device, etc.). The combustion of the air-fuel mixture can increase the temperature of the piston.

Summary of the Invention

Means for Solving the Problems

[0003] Various embodiments relate to a piston head. The piston head includes an upper portion including an upper wall, an outer wall extending around the periphery of the upper wall, and an inner wall disposed radially inward of the outer wall. A cooling passage is defined between the outer wall and the inner wall. The piston head further includes a lower portion extending downward from the upper portion. The lower portion includes an upper surface and a skirt extending from the upper surface in a direction away from the upper portion. The skirt defines a pin hole for receiving a pin. The pin hole is centered about a pin hole central axis. A portion of the skirt between the pin hole central axis and a skirt reference axis has a vertical profile that is substantially non-linear. The skirt reference axis is orthogonal to the pin hole central axis and parallel to the upper surface.

[0004] In some embodiments, the vertical profile of the skirt at the skirt reference axis is substantially linear.

[0005] In some embodiments, the average slope of the vertical profile of a portion of the skirt increases in a circumferential direction extending from the skirt reference axis to the pin hole central axis.

[0006] In some embodiments, a portion of the skirt extends from an angle greater than 0 degrees relative to the skirt reference axis to an angle relative to the skirt reference axis corresponding to the edge of the pin hole.

[0007] In some embodiments, a portion of the skirt includes an upper end proximate to the upper surface and a lower end distal from the upper surface. The lower end is disposed closer to the inner wall than the upper end in the radial direction.

[0008] In some embodiments, the inner wall extends from the upper wall of the upper portion to the upper surface of the lower portion.

[0009] In some embodiments, a gap is defined between the outer wall of the upper portion and the upper surface of the lower portion.

[0010] In some embodiments, V min = 0.03D bore 2 H compression where V min is the minimum open volume of the cooling passage, D bore is the diameter of the pin hole, and H compression is the compression height defined as the height extending from the upper wall to the center axis of the pin hole.

[0011] In some embodiments, V max = 0.25D bore 2 H compression where V max is the maximum open volume of the cooling passage, D bore is the diameter of the pin hole, and H compression is the compression height defined as the height extending from the upper wall to the center axis of the pin hole.

[0012] In some embodiments, the piston head is a single-piece piston head forged from steel.

[0013] Various embodiments relate to a piston head assembly including a piston head. The piston head includes an upper portion including an outer wall and an inner wall disposed radially inward of the outer wall. A cooling passage is at least partially defined between the outer wall and the inner wall. The piston head further includes a lower portion extending downward from the upper portion. The lower portion includes an upper surface and a skirt extending from the upper surface. The skirt defines a pin hole centered on a pin hole central axis. A portion of the skirt between the pin hole central axis and a skirt reference axis has a curved vertical profile. The skirt reference axis intersects the pin hole central axis. The piston head assembly further includes a plurality of locking plates coupled to the upper portion. Each locking plate extends between the outer wall and the inner wall. The cooling passage is defined between the outer wall, the inner wall, and the plurality of locking plates.

[0014] In some embodiments, the locking plates include a first locking plate and a second locking plate. The first locking plate and the second locking plate are parallel to the upper surface of the lower portion.

[0015] In some embodiments, each of the locking plates defines an inlet for receiving cooling fluid and passing the cooling fluid into the cooling passage. The inlet defines an inlet opening region. Each of the locking plates further defines an outlet for receiving cooling fluid from the cooling passage and discharging the cooling fluid out of the cooling passage. The outlet defines an outlet opening region smaller than the inlet opening region. The upper surface of the lower portion defines at least one inlet port for receiving cooling fluid and passing the cooling fluid into the corresponding inlet of the plurality of locking plates, and at least one outlet port for receiving cooling fluid from the outlet of the corresponding locking plate.

[0016] In some embodiments, each of the locking plates includes a first edge and a second edge opposite and coaxial with the first edge. The first edge and the second edge extend along a first plate reference axis. Each of the locking plates further includes a tab disposed between the first edge and the second edge at a non-zero angle with respect to a second plate reference axis. The second plate reference axis is orthogonal to the first plate reference axis and parallel to the upper surface of the lower portion. The tab engages the outer wall.

[0017] In some embodiments, the non-zero angle extends circumferentially from the second plate reference axis towards the first edge.

[0018] In some embodiments, each of the locking plates defines an inlet between the tab and the second edge. The inlet receives the cooling fluid and passes the cooling fluid into the cooling passage. Each of the locking plates further defines an outlet between the tab and the first edge. The outlet receives the cooling fluid from the cooling passage and discharges the cooling fluid out of the cooling passage.

[0019] In some embodiments, the non-zero angle is greater than 0 degrees and less than or equal to 10 degrees.

[0020] In some embodiments, the non-zero angle is 3 degrees.

[0021] In some embodiments, the second plate reference axis is parallel to the pin hole central axis.

[0022] In some embodiments, the first plate reference axis is parallel to the skirt reference axis.

[0023] Details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the present disclosure will become apparent from the description, the drawings, and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

DETAILED DESCRIPTION OF THE INVENTION

[0025] It is to be recognized that the figures are schematic depictions for illustrative purposes. The figures are provided for the purpose of illustrating one or more implementations with the explicit understanding that they are not used to limit the scope or meaning of the claims.

[0026] Following are various concepts related to methods, apparatuses, and systems for a piston head assembly of an internal combustion engine, as well as more detailed descriptions of the implementation of those methods, apparatuses, and systems. The various concepts introduced above and discussed in more detail below can be implemented in any of several ways so that the concepts described are not limited to the techniques of any specific implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.

[0027] Figures 1 to 5 depict a piston head assembly 100. The piston head assembly 100 can be part of an engine (e.g., an internal combustion engine), such as a spark ignition engine or a compression ignition engine. Examples of engines include hydrogen engines, diesel engines, gasoline engines, propane engines, dual fuel engines, natural gas engines, etc. The engine is configured to burn at least one fuel (e.g., hydrogen, diesel, gasoline, propane, natural gas, etc., or a combination of fuels) to generate energy that can be utilized at various outputs. For example, the engine can generate energy to drive a moving member (e.g., a wheel, a ground contact surface, a propeller, a fan, a turbine, a rotor, etc.) or to power a generator. The engine can be implemented in a vehicle (e.g., a truck, an automobile, a construction vehicle, a freight vehicle, a commercial vehicle, an emergency vehicle, a military vehicle, a ship, etc.).

[0028] In some embodiments, the piston head assembly 100 can correspond to a combustion chamber assembly of an engine configured to burn fuel. For example, the combustion chamber assembly can include a cylinder (e.g., a combustion chamber, etc.) configured to receive the piston head assembly 100. The cylinder can include a cylinder liner or a cylinder wall that at least partially defines an internal volume. The cylinder is configured to receive air from an air intake and fuel from a fuel injector. A mixture of air and fuel can be burned within the internal volume of the cylinder.

[0029] The piston head assembly 100 includes a piston head 102. The piston head assembly 100 can be part of a piston assembly. The piston assembly can include a connecting rod that is connected to the piston head 102 via a pin (e.g., a piston pin, etc.) that is received in a pin hole of the piston head 102. The connecting rod can be configured to be connected to a crankshaft of an engine. The piston head 102 and the cylinder wall can define an internal volume together such that when an air-fuel mixture is combusted, the piston head 102 is axially translated within the cylinder by the force of combustion. One or more cylinder rings can be disposed between the piston head 102 and the cylinder liner. The cylinder ring is configured to form a seal between the piston head 102 and the cylinder liner.

[0030] Figures 1 - 5 depict a piston head assembly 100 that includes a piston head 102. The piston head 102 includes an upper portion 110 that includes an upper wall 112, an outer wall 114 that extends around the periphery of the upper wall 112, and an inner wall 116 that is disposed radially inward of the outer wall 114. A cooling passage 118 is defined between the outer wall 114 and the inner wall 116. The piston head 102 includes a lower portion 120 that extends downward from the upper portion 110. The lower portion 120 includes an upper surface 122 and a skirt 130 that extends from the upper surface 122 in a direction away from the upper portion 110. The skirt 130 defines a pin hole 140 that is configured to receive a pin. The pin hole 140 is centered about a pin hole central axis 142. A portion of the skirt 130 between the pin hole central axis 142 and a skirt reference axis 144 has a vertical profile that is substantially non-linear. The skirt reference axis 144 is orthogonal to the pin hole central axis 142 and is parallel to the upper surface 122.

[0031] According to various embodiments, the piston head assembly 100 includes a piston head 102. The piston head 102 includes an upper portion 110 that includes an outer wall 114 and an inner wall 116 disposed radially inward of the outer wall 114. A cooling passage 118 is at least partially defined between the outer wall 114 and the inner wall 116. The piston head 102 further includes a lower portion 120 that extends downward from the upper portion 110. The lower portion 120 includes an upper surface 122 and a skirt 130 that extends from the upper surface 122. The skirt 130 defines a pin hole 140 that is centered on a pin hole central axis 142. A portion of the skirt 130 between the pin hole central axis 142 and a skirt reference axis 144 has a curved vertical profile. The skirt reference axis 144 intersects the pin hole central axis 142. The piston head assembly 100 further includes a plurality of locking plates 150 coupled to the upper portion 110. Each locking plate 150 extends between the outer wall 114 and the inner wall 116. The cooling passage 118 is defined between the outer wall 114, the inner wall 116, and the plurality of locking plates 150.

[0032] The outer wall 114 can extend axially toward the lower portion 120 around the periphery of the upper wall 112. The outer wall 114 of the upper portion 110 can include a plurality of ring grooves 115. Each of the ring grooves 115 is configured to receive a cylinder ring configured to form a seal between the piston head 102 and a cylinder liner.

[0033] The inner wall 116 can extend from the upper wall 112 of the upper portion 110 to the upper surface 122 of the lower portion 120. A gap 123 can be defined between the outer wall 114 of the upper portion 110 and the upper surface 122 of the lower portion 120. The gap 123 can improve the cooling characteristics of the cooling passage 118 by reducing the surface area that the cooling fluid contacts and cools, thereby providing more efficient and faster cooling. The gap 123 can reduce the total mass of the piston head 102, thereby improving engine characteristics.

[0034] As shown in FIG. 3, the upper wall 112 may include a first portion that defines a substantially concave shape. The upper wall 112 may further include a second portion that is positioned radially inward of the first portion and defines a substantially convex shape.

[0035] A portion of the skirt 130 having a substantially non-linear vertical profile may include an upper end proximate to the upper surface 122 and a lower end distal from the upper surface 122. In some embodiments, the lower end is disposed closer to the inner wall 116 than the upper end in the radial direction. For example, a lower end radius extending from the skirt central axis 131 of the skirt 130 (i.e., the skirt 130 is centered along the skirt central axis 131) to the lower end is smaller than an upper end radius extending from the skirt central axis 131 to the upper end. In other embodiments, the upper end is disposed closer to the inner wall 116 than the lower end in the radial direction. For example, the upper end radius is smaller than the lower end radius. In some embodiments, a portion of the skirt 130 has a curved vertical profile (e.g., a curved vertical profile).

[0036] In some embodiments, the piston head 102 is a single-piece piston head (e.g., manufactured from a single piece of material, etc.). The single-piece piston head can simplify the process of manufacturing the piston head 102, provide a relatively high structural strength for the piston head 102, and / or provide a relatively high thermal strength for the piston head 102. In some further embodiments, the piston head 102 that is a single-piece piston head is forged from a metal. For example, the metal can be steel, aluminum metal, etc. In other embodiments, the piston head 102 can be manufactured from various elements that are integrally connected via welding, adhesives, etc.

[0037] As shown in FIGS. 1 and 3 - 5, the piston head assembly 100 includes a piston head 102 and a plurality of locking plates 150 connected to the upper portion 110 of the piston head 102. Each of the locking plates 150 extends between an outer wall 114 and an inner wall 116. The inner wall 116 may include a shoulder portion 117 configured to receive at least a portion of each of the locking plates 150 and connect each of the locking plates 150 to the inner wall 116. A cooling passage 118 can be defined between the outer wall 114, the inner wall 116, and the plurality of locking plates 150. The locking plates 150 can be parallel or substantially parallel to the upper surface 122 of the lower portion 120.

[0038] In some embodiments, the locking plate 150 includes two locking plates. For example, as shown in FIG. 4, the locking plate 150 includes a first locking plate 152 and a second locking plate 154. In some embodiments, the first locking plate 152 and the second locking plate 154 have equal mass, volume, and / or surface area. In other embodiments, the first locking plate 152 and the second locking plate 154 have unequal mass, volume, and / or surface area.

[0039] In other embodiments (not shown), the locking plate 150 includes fewer than two locking plates (e.g., one locking plate) or more than two locking plates (e.g., three locking plates, four locking plates, seven locking plates, etc.). In some further embodiments, the locking plates 150 have equal mass, volume, and / or surface area. In other further embodiments, the locking plates 150 have unequal mass, volume, and / or surface area.

[0040] Each of the locking plates 150 defines an inlet 156 configured to receive a cooling fluid and pass the cooling fluid into the cooling passage 118. Each of the locking plates 150 further defines an outlet 158 configured to receive the cooling fluid from the cooling passage 118 and discharge the cooling fluid out of the cooling passage 118.

[0041] In some embodiments, the inlet 156 can define an inlet opening area that is larger than the outlet opening area of the outlet 158, thereby allowing sufficient cooling fluid to be retained in the cooling passage 118 for sufficient cooling of the piston head 102, specifically, at least a portion of the upper wall 112, the outer wall 114 (including the ring groove 115), and / or the inner wall 116. In other embodiments, the inlet opening area can be equal to or approximately equal to the outlet opening area. In still other embodiments, the inlet opening area can be smaller than the outlet opening area.

[0042] As shown in FIG. 4, each of the locking plates 150 can include a first edge 160 and a second edge 162 opposite the first edge 160. The first edge 160 and the second edge 162 can be coaxial. The first edge 160 and the second edge 162 can extend along a first plate reference axis 164. The first plate reference axis 164 can be parallel to the skirt reference axis 144. In some embodiments, the skirt reference axis 144 can be offset from the pin hole center axis 142. As shown in FIG. 4, the skirt reference axis 144 intersects the pin hole center axis 142. For example, the skirt reference axis 144 can be perpendicular to the pin hole center axis 142.

[0043] Each of the locking plates 150 can include a tab 166 disposed between the first edge 160 and the second edge 162. The tab 166 is configured to engage with a tab groove in the outer wall 114 via a snap fit (e.g., friction fit, etc.), thereby connecting the corresponding locking plate of the locking plate 150 to the outer wall 114. The tab groove in the outer wall 114 can be defined along the inner surface of the outer wall 114, and the ring groove 115 is defined along the outer surface of the outer wall 114 opposite the inner surface of the outer wall 114. The combination of the tab 166 and the shoulder portion 117 of the inner wall 116 can connect the corresponding locking plate to the upper portion 110.

[0044] The tab 166 can be disposed between the first edge 160 and the second edge 162 at a first non-zero angle A1 with respect to the second plate reference axis 168. The second plate reference axis 168 can be orthogonal to the first plate reference axis 164 and parallel to the upper surface 122 of the lower portion 120. The second plate reference axis 168 can be parallel to the pin hole central axis 142. The first non-zero angle A1 can extend circumferentially from the second plate reference axis 168 towards the first edge 160. The tab groove of the outer wall 114 configured to receive the tab 166 can be disposed along the inner surface of the outer wall 114 at an angle with respect to the second plate reference axis 168 that is equal to or approximately equal to the first non-zero angle A1.

[0045] In some embodiments, as shown in FIG. 4, the locking plate 150 includes a first locking plate 152 and a second locking plate 154. The tab 166 of the first locking plate 152 can be disposed between the first edge 160 and the second edge 162 at a first non-zero angle A1 with respect to the second plate reference axis 168. The tab 166 of the second locking plate 154 can be disposed between the first edge 160 and the second edge 162 at a second non-zero angle A2 with respect to the second plate reference axis 168. The second non-zero angle A2 can extend circumferentially from the second plate reference axis 168 towards the first edge 160. The first non-zero angle A1 and the second non-zero angle A2 can connect the first locking plate 152 and the second locking plate 154 to the upper portion 110 only in the correct orientation with respect to the inlet 156 and the outlet 158, thereby ensuring that the inlets 156 of both the first locking plate 152 and the second locking plate 154 are positioned in the correct position with respect to the injection of the coolant fluid (discussed in more detail herein).

[0046] The first non-zero angle A1 and the second non-zero angle A2 are angled to prevent the first locking plate 152 and the second locking plate 154 from being assembled in an incorrect orientation. Incorrect orientations include the first locking plate 152 and the second locking plate 154 being positioned in opposite positions relative to each other (e.g., positions swapped relative to the first plate reference axis 164). If the grooves inside the outer wall 114 configured to receive the tabs 166 of the first locking plate 152 and the second locking plate 154 are angled at the first non-zero angle A1 and the second non-zero angle A2 relative to the second plate reference axis 168 based on the correct orientations of the first locking plate 152 and the second locking plate 154, the tabs 166 will be received in their non-corresponding inner grooves, and if the first locking plate 152 and the second locking plate 154 are in opposite positions, as a result, (i) the first locking plate 152 and the second locking plate 154 will at least partially overlap, and (ii) the inlet 156 of at least one of the first locking plate 152 or the second locking plate 154 will be in an incorrect position for coolant injection.

[0047] Other incorrect orientations may include using two first locking plates 152 instead of one first locking plate 152 and one second locking plate 154, or using two second locking plates 154 instead of one first locking plate 152 and one second locking plate 154. Both of these incorrect orientations will result in (i) the locking plates overlapping each other (e.g., two first locking plates 152 at least partially overlapping, two second locking plates 154 at least partially overlapping, etc.), and (ii) the inlet 156 of at least one of the first locking plate 152 or the second locking plate 154 being in an incorrect position for coolant injection.

[0048] In some embodiments, the first non-zero angle A1 and the second non-zero angle A2 are equal or approximately equal. In other embodiments, the first non-zero angle A1 and the second non-zero angle A2 are not equal. In some embodiments, at least one of the first non-zero angle A1 or the second non-zero angle A2 is greater than 0 degrees and less than or equal to 10 degrees, preferably equal to or approximately equal to 3 degrees. In other embodiments, at least one of the first non-zero angle A1 or the second non-zero angle A2 is greater than 0 degrees and less than 90 degrees.

[0049] In some embodiments, as shown in FIG. 4, at least one of the first non-zero angle A1 or the second non-zero angle A2 extends circumferentially from the second plate reference axis 168 towards the first edge 160. In other embodiments (not shown), at least one of the first non-zero angle A1 or the second non-zero angle A2 extends circumferentially from the second plate reference axis 168 towards the second edge 162.

[0050] In some embodiments, as shown in FIG. 4, the inlet 156 is defined between the tab 166 and the second edge 162, and the outlet 158 is defined between the tab 166 and the first edge 160. In other embodiments (not shown), the inlet 156 is defined between the tab 166 and the first edge 160, and the outlet 158 is defined between the tab 166 and the second edge 162.

[0051] The engine may include a coolant injection system positioned proximate to the combustion chamber assembly. The coolant injection system can include nozzles for supplying a fluid (e.g., oil, coolant, lubricant, etc.). The nozzles can extend towards the piston head 102 so as to supply coolant to the piston head 102.

[0052] As shown in FIGS. 1 and 2, the upper surface 122 of the lower part 120 can define at least one inlet port 124 configured to receive a cooling fluid via a nozzle of a coolant injection system and pass the cooling fluid to an inlet 156 of a corresponding locking plate among the locking plates 150. The upper surface 122 of the lower part 120 can further define at least one outlet port 126 configured to receive the cooling fluid from an outlet 158 of a corresponding locking plate and discharge the received cooling fluid downstream of the outlet port 126.

[0053] The open volume of the cooling passage 118 can be defined by the outer wall 114, the inner wall 116, and the plurality of locking plates 150. The minimum open volume (V min ) of the cooling passage 118 can be determined based on Equation (1) as shown below. V min =0.03D bore 2 H compression (1)

[0054] The minimum open volume (V min ) determined based on Equation (1) depends on the diameter (D bore ) of the pin hole 140 and the compression height (H compression or H comp ) defined as the height extending from the upper wall 112 to the central axis 142 of the pin hole. The minimum open volume (V min ) determined based on Equation (1) can be the minimum open volume of the cooling passage 118 that enables proper cooling of the piston head 102 through the cooling fluid in the cooling passage 118 and / or simplifies the manufacturing process of the piston head 102.

[0055] The maximum open volume (V max ) of the cooling passage 118 can be determined based on Equation (2) as shown below. V max =0.25D bore 2 H compression (2)

[0056] The maximum opening volume (V max ) determined based on Equation (2) depends on the diameter (D bore ) of the pin hole 140 and the compression height (H comp ) defined as the height extending from the upper wall 112 to the pin hole central axis 142. The minimum opening volume (V max ) determined based on Equation (2) can be the maximum opening volume of the cooling passage 118 that enables an appropriate structural strength of the piston head 102, enables an appropriate thermal strength of the piston head 102 against thermal stress, and / or simplifies the manufacturing process of the piston head 102.

[0057] FIG. 6 shows a diagram of the vertical profile 200 of a skirt (e.g., skirt 130), including, on the x-axis, the radial displacement of the skirt 130 with respect to the skirt reference axis 144, and, on the y-axis, the distance from the lower part of the skirt (e.g., the second edge 162 of the skirt 130, etc.). Zero in the radial displacement can correspond to the radius of the skirt 130 at the skirt reference axis 144. The values provided on the x-axis and y-axis of FIG. 6 are for illustrative purposes only, such that the values of the radial displacement and the distance from the lower part of the skirt are not limited to the presented values, and values other than the presented values (i.e., within the presented range, outside the presented range, etc.) can be included.

[0058] As shown in FIGS. 1-3, the skirt 130 can include an upper edge 132 close to the upper surface 122 and a lower edge 134 distal from the upper surface 122. The vertical profile 200 shown in FIG. 6 is orthogonal to the pin hole central axis 142 and includes a first vertical skirt profile 210 in a skirt reference plane 145 along which the skirt reference axis 144 extends. The first vertical skirt profile 210 can be substantially linear.

[0059] In some embodiments, at least a portion of the first vertical skirt profile 210 is curved. In some examples, both the radius of the lower edge 134 extending along the skirt reference plane 145 from the skirt central axis 131 and the radius of the upper edge 132 extending along the skirt reference plane 145 from the skirt central axis 131 are smaller than the radius of the skirt 130 between the upper edge 132 and the lower edge 134 extending along the skirt reference plane 145 from the skirt central axis 131. In other examples, the radius of the lower edge 134 along the skirt reference plane 145 may be smaller than the radius of the upper edge 132 along the skirt reference plane 145.

[0060] In other embodiments, the first vertical skirt profile 210 is flat or substantially flat. For example, the radius of the lower edge 134 along the skirt reference plane 145 can be equal to or approximately equal to the radius of the upper edge 132 along the skirt reference plane 145 and the radius of the skirt 130 between the upper edge 132 and the lower edge 134 along the skirt reference plane 145.

[0061] The vertical profile 200 is orthogonal to the skirt reference axis 144 and the skirt reference plane 145 and includes a second vertical skirt profile 220 in a pin hole plane 143 along which the pin hole central axis 142 extends. The second vertical skirt profile 220 can be substantially linear. In some embodiments, at least a portion of the second vertical skirt profile 220 is curved. In other embodiments, the second vertical skirt profile 220 is flat or substantially flat.

[0062] The vertical profile 200 includes a third vertical skirt profile 230 in the pin hole plane 143. The third vertical skirt profile 230 can be substantially non-linear as shown by the radial displacement in FIG. 6 between a distance of 0 and a distance of 30 from the lower part of the skirt. The substantially non-linear profile of the third vertical skirt profile 230 can prevent or minimize accidental contact between the lower part of the skirt (e.g., the second edge 162 of the skirt 130) and the cylinder liner. Specifically, accidental contact can be avoided during thermo-mechanical deformation, thereby minimizing damage to the piston head 102 and the cylinder liner.

[0063] In some embodiments, the substantially linear profile of the second vertical skirt profile 220 includes one substantially constant slope throughout the vertical profile or throughout most of the vertical profile. In other embodiments, the substantially linear profile of the second vertical skirt profile 220 includes two or more slopes along the vertical profile. In some further embodiments, both the substantially linear profile of the second vertical skirt profile 220 and the substantially non-linear profile of the third vertical skirt profile 230 include two or more slopes along their respective vertical profiles. In these embodiments, the substantially linear vertical profile of the second vertical skirt profile 220 and the substantially non-linear profile of the third vertical skirt profile 230 have different degrees of freedom between their respective two or more slopes (i.e., the degree of freedom (e.g., the maximum difference, etc.) between the first slope and the second slope of the two or more slopes). More specifically, the two or more slopes corresponding to the substantially non-linear profile (e.g., the third vertical skirt profile 230) have a greater degree of freedom than the two or more slopes corresponding to the substantially linear profile (e.g., the second vertical skirt profile 220).

[0064] In some embodiments, at least a portion of the third vertical skirt profile 230 is curved. In further embodiments, the curvature of the third vertical skirt profile 230 can increase as the distance from the lower portion of the skirt (e.g., the second edge 162 of skirt 130) decreases (e.g., the radial displacement increases). In other embodiments, the third vertical skirt profile 230 is flat or substantially flat.

[0065] FIG. 7 shows a diagram of the vertical profile 300 of skirt 130 at various angles relative to the skirt reference plane 145. The diagram of the vertical profile 300 includes, on the y-axis, the radial displacement of skirt 130 relative to the skirt reference axis 144, and on the x-axis, the distance from the lower portion of the skirt (e.g., the second edge 162 of skirt 130, etc.). Zero in the radial displacement can correspond to the radius of skirt 130 at the skirt reference axis 144. It is understood that the values provided on the x-axis and y-axis of FIG. 7 are for illustrative purposes only so that the values of the radial displacement and the distance from the lower portion of the skirt are not limited to the presented values and values other than the presented values can be included.

[0066] The vertical profile 300 includes a first angle vertical skirt profile 310 at a first angle relative to the skirt reference plane 145. The first angle can be equal to or approximately equal to 0 degrees such that the first angle vertical skirt profile 310 becomes the skirt reference plane 145. In some embodiments, as shown in FIG. 7, the first angle vertical skirt profile 310 is flat or substantially flat. In other embodiments, at least a portion of the first angle vertical skirt profile 310 is curved.

[0067] The vertical contour 300 further includes a second-angle vertical skirt contour 320 at a second angle with respect to the skirt reference plane 145, a third-angle vertical skirt contour 330 at a third angle with respect to the skirt reference plane 145, a fourth-angle vertical skirt contour 340 at a fourth angle with respect to the skirt reference plane 145, a fifth-angle vertical skirt contour 350 at a fifth angle with respect to the skirt reference plane 145, a sixth-angle vertical skirt contour 360 at a sixth angle with respect to the skirt reference plane 145, and a seventh-angle vertical skirt contour 370 at a seventh angle with respect to the skirt reference plane 145. The second angle can be equal to or approximately equal to 15 degrees, the third angle can be equal to or approximately equal to 30 degrees, the fourth angle can be equal to or approximately equal to 45 degrees, the fifth angle can be equal to or approximately equal to 60 degrees, the sixth angle can be equal to or approximately equal to 75 degrees, and the seventh angle can be equal to or approximately equal to 90 degrees (i.e., it can be on the pin hole central axis 142).

[0068] As shown in FIG. 7, at least some of the second-angle vertical skirt contour 320, the third-angle vertical skirt contour 330, the fourth-angle vertical skirt contour 340, the fifth-angle vertical skirt contour 350, the sixth-angle vertical skirt contour 360, and the seventh-angle vertical skirt contour 370 are substantially non-linear.

[0069] The average inclination of the vertical profile of a portion of the skirt 130 having a substantially non-linear vertical profile can increase in the circumferential direction extending from the skirt reference plane 145 to the pin hole plane 143 or from the skirt reference plane 145 to the pin hole central axis 142. More specifically, the average inclination of the radial displacement over the distance from the lower part of the skirt for the vertical profiles 310-370 (i.e., the first angular vertical skirt profile 310, the second angular vertical skirt profile 320, the third angular vertical skirt profile 330, the fourth angular vertical skirt profile 340, the fifth angular vertical skirt profile 350, the sixth angular vertical skirt profile 360, and the seventh angular vertical skirt profile 370) can increase as the angle with respect to the skirt reference plane 145 increases.

[0070] For example, the average inclination of the seventh angular vertical skirt profile 370 can be greater than the average inclination of the sixth angular vertical skirt profile 360, the average inclination of the sixth angular vertical skirt profile 360 can be greater than the average inclination of the fifth angular vertical skirt profile 350, the average inclination of the fifth angular vertical skirt profile 350 can be greater than the average inclination of the fourth angular vertical skirt profile 340, the average inclination of the fourth angular vertical skirt profile 340 can be greater than the average inclination of the third angular vertical skirt profile 330, the average inclination of the third angular vertical skirt profile 330 can be greater than the average inclination of the second angular vertical skirt profile 320, and / or the average inclination of the second angular vertical skirt profile 320 can be greater than the average inclination of the first angular vertical skirt profile 310.

[0071] In some embodiments, the piston head 102 does not physically include at least one of the vertical profiles 310 - 370. In these embodiments, at least one of the vertical profiles 310 - 370 that is not physically included in the piston head 102 is utilized to model and / or design the piston head 102 by assisting in the generation of the other vertical profiles among the vertical profiles 310 - 370 through interpolation. In some examples, at least one of the vertical profiles 310 - 370 that is not physically included in the piston head 102 includes a seventh angular vertical skirt profile 370 at the pin hole plane 143. In some examples, at least one of the vertical profiles 310 - 370 that is not physically included in the piston head 102 includes a sixth angular vertical skirt profile 360 and a seventh angular vertical skirt profile 370.

[0072] In some embodiments, the piston head 102 does not include a substantially non-linear vertical profile in the vicinity of the pin hole 140. For example, a portion of the skirt 130 having a substantially non-linear vertical profile can extend at an angle greater than 0 degrees with respect to the skirt reference plane 145 (or skirt reference axis 144) to an angle with respect to the skirt reference plane 145 (or skirt reference axis 144) corresponding to the edge of the pin hole 140.

[0073] This specification includes details of many specific implementations, which should not be construed as limitations on the scope of what can be claimed, but rather as descriptions of features specific to particular implementations. Specific features described herein in the context of one implementation may be implemented in combination in a single implementation. Conversely, the various features described in the context of a single implementation may be implemented separately or in any suitable sub-combination in multiple implementations. Further, features may be described as acting in a particular combination and may even be claimed as such initially, but one or more features from the claimed combination may in some cases be deleted from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

[0074] As used herein, terms such as "substantially", "generally", "approximately", and similar terms are intended to have a broad meaning consistent with the commonly accepted use by those skilled in the art to which the subject matter of this disclosure pertains. It should be understood by those skilled in the art considering this disclosure that these terms are intended to allow the description of the specific features recited and claimed without restricting the scope of these features to the exact numerical ranges provided. Accordingly, these terms should be construed as indicating that non-substantive or non-logical changes or substitutions to the subject matter described and claimed are considered to be within the scope of the appended claims.

[0075] Unless otherwise indicated, all amounts expressed in terms of numerical values of properties, parameters, conditions, etc. used in this specification and the claims are to be understood as being modified in all instances by the term "about" or "approximately." Accordingly, unless otherwise indicated, the numerical parameters set forth in this specification and the appended claims are approximations. All numerical parameters should be construed, at least, in light of the number of reported significant digits and by applying ordinary rounding techniques. The term "about" or "approximately" when used prior to an indication of a numerical value, such as in the case of ranges including temperature, time, amount, and concentration, indicates an approximation that can vary by (+) or (-) 10%, 5%, or 1%.

[0076] As used herein, terms such as "connected" mean a direct or indirect coupling of two components to each other. Such a coupling can be stationary (e.g., permanent) or movable (e.g., removable or releasable). Such a coupling can be achieved by the two components, or the two components and any additional intermediate components, being integrally formed as a single unitary body with each other, or by the two components, or the two components and any additional intermediate components, being attached to each other.

[0077] In some cases, terms such as "connected to" in relation to a fluid system can mean that two components or objects have a passage formed between them through which a fluid such as air, process fluid, air - process fluid mixture, exhaust, hydrocarbon fluid, air - hydrocarbon fluid mixture, etc. can flow, with or without intervening components or objects. Examples of such connections or configurations to enable fluid communication can include piping, passages, or any other suitable components to allow fluid flow from one component or object to another.

[0078] It is important to note that the structures and arrangements of the various systems shown in the implementation forms of the various examples are merely illustrative and do not constitute a constraint in nature. All changes and improvements that fall within the spirit and / or scope of the described implementation forms are desired to be protected. It should be understood that some of the features may not be necessary, and implementation forms lacking various features may be considered within the scope defined by the appended claims as being within the scope of this disclosure. When the term "a part" is used, that item may include part of the item and / or the whole item unless it is clearly stated otherwise.

[0079] Also, when the term "or" is used to connect a listing of elements, it is used in its inclusive sense (and not in its exclusive sense) in the context of the listing of elements to mean one, some, or all of the elements in that listing. Connective language such as the expression "at least one of X, Y, and Z" is understood in the context in which it is used to convey that the items, terms, etc. can generally be any of X, Y, Z, X and Y, X and Z, Y and Z, or X, Y, and Z (i.e., any combination of X, Y, and Z), unless otherwise clearly stated. Thus, such connective language is generally not intended to mean that a particular implementation form requires at least one of each of the X's, at least one of each of the Y's, and at least one of each of the Z's that exist, unless otherwise indicated.

[0080] In addition, the use of value ranges in this specification (e.g., W1 to W2, etc.) includes their maximum and minimum values (e.g., W1 to W2 includes W1 and includes W2, etc.) unless otherwise indicated. Further, a value range (e.g., W1 to W2, etc.) may or may not include intermediate values within the value range (e.g., W1 to W2 may include only W1 and W2, etc.).

Description of Reference Numerals

[0081] 100 Piston head assembly 102 Piston head 110 Upper part 112 Upper wall 114 Outer wall 115 Ring groove 116 Inner wall 117 Shoulder portion 118 Cooling passage 120 Lower part 122 Upper surface 123 Gap 124 Inlet port 126 Outlet port 130 Skirt 131 Skirt central axis 132 Upper edge 134 Lower edge 140 Pin hole 142 Pin hole central axis 143 Pin hole plane 144 Skirt reference axis 150 Locking plate 152 First locking plate 154 Second locking plate 156 Inlet 158 Outlet 160 First edge 162 Second edge 166 Tab 210 First vertical skirt profile 220 Second vertical skirt profile 230 Third vertical skirt profile 310 First angular vertical skirt profile 320 Second angular vertical skirt profile 330 Third angular vertical skirt profile 340 Fourth angular vertical skirt profile 350 Fifth angular vertical skirt profile 360 Sixth angular vertical skirt profile 370 Seventh angular vertical skirt profile A1 First non-zero angle A2 A non-zero angle of the second

Claims

1. An upper portion comprising: an upper wall, an outer wall extending around the periphery of the upper wall, and an inner wall disposed radially inward of the outer wall such that a cooling passage is defined between the outer wall and the inner wall; an upper portion, a lower portion extending downward from the upper portion, the lower portion comprising: an upper surface, and a skirt extending from the upper surface in a direction away from the upper portion, the skirt defining a pin hole configured to receive a pin, the pin hole being centered on a pin hole central axis; wherein a portion of the skirt between the pin hole central axis and a skirt reference axis that is orthogonal to the pin hole central axis and parallel to the upper surface has a substantially non-linear vertical profile; a lower portion; a piston head.

2. The piston head according to claim 1, wherein the vertical profile of the skirt at the skirt reference axis is substantially linear.

3. The piston head according to claim 1, wherein an average inclination of the vertical profile of the portion of the skirt increases in a circumferential direction extending from the skirt reference axis to the pin hole central axis.

4. The piston head according to claim 1, wherein the portion of the skirt extends from an angle greater than 0 degrees with respect to the skirt reference axis to an angle with respect to the skirt reference axis corresponding to an edge of the pin hole.

5. The piston head according to claim 1, wherein the portion of the skirt comprises: an upper end proximate to the upper surface, and a lower end distal from the upper surface and disposed radially closer to the inner wall than the upper end.

6. The piston head according to claim 1, wherein the inner wall extends from the upper wall of the upper portion to the upper surface of the lower portion.

7. The piston head according to claim 1, wherein a gap is defined between the outer wall of the upper portion and the upper surface of the lower portion.

8. wherein...

9. wherein... V min = 0.03D bore 2 H compression

10. V min is the minimum open volume of the cooling passage, D bore is the diameter of the pin hole, H compression is defined as the compression height extending from the upper wall to the center axis of the pin hole The piston head according to claim 1, which is a single-piece piston head forged from steel.

11. V max = 0.25 D bore 2 H compression A piston head comprising: V max is the maximum open volume of the cooling passage, D bore is the diameter of the pin hole, H compression is defined as the compression height extending from the upper wall to the center axis of the pin hole an upper portion comprising: an outer wall, and an inner wall disposed radially inward of the outer wall such that a cooling passage is at least partially defined between the outer wall and the inner wall; an upper portion, as well as ... ... ... ... ... ... A lower part extending downward from the upper part, an upper surface, and a skirt extending from the upper surface, the skirt defining a pin hole centered on a pin hole central axis, and a portion of the skirt between the pin hole central axis and a skirt reference axis intersecting the pin hole central axis having a curved vertical contour, the skirt comprising the lower part comprising a piston head, and a plurality of locking plates connected to the upper part and each extending between the outer wall and the inner wall, the cooling passages being defined between the outer wall, the inner wall, and the plurality of locking plates, the plurality of locking plates comprising a piston head assembly.

12. The locking plate comprises a first locking plate and a second locking plate, and the first locking plate and the second locking plate are parallel to the upper surface of the lower part. The piston head assembly according to claim 11.

13. Each of the locking plates has an inlet configured to receive a cooling fluid and pass the cooling fluid into the cooling passage, the inlet defining an inlet opening region, and an outlet configured to receive the cooling fluid from the cooling passage and discharge the cooling fluid out of the cooling passage, the outlet defining an outlet opening region smaller than the inlet opening region, the outlet defining, the upper surface of the lower part has at least one inlet port configured to receive the cooling fluid and pass the cooling fluid into the corresponding inlet of the plurality of locking plates, and at least one outlet port configured to receive the cooling fluid from the outlet of the corresponding locking plate, defining the piston head assembly according to claim 11.

14. Each of the locking plates has a first edge, and a second edge opposite the first edge and coaxial with the first edge, the first axis and the second axis extending along a first plate reference axis, the second edge, and a tab disposed at a non-zero angle between the first edge and the second edge with respect to a second plate reference axis that is orthogonal to the first plate reference axis and parallel to the upper surface of the lower part, the tab being configured to engage the outer wall, the tab comprising the piston head assembly according to claim 11.

15. The non-zero angle extends circumferentially from the second plate reference axis toward the first edge. The piston head assembly according to claim 14.

16. Each of the locking plates An inlet that is between the tab and the second edge, configured to receive a cooling fluid and pass the cooling fluid into the cooling passage; An outlet that is between the tab and the first edge, configured to receive the cooling fluid from the cooling passage and discharge the cooling fluid out of the cooling passage The piston head assembly according to claim 14, defining the same.

17. The piston head assembly according to claim 14, wherein the non-zero angle is greater than 0 degrees and equal to or less than 10 degrees.

18. The piston head assembly according to claim 17, wherein the non-zero angle is 3 degrees.

19. The piston head assembly according to claim 14, wherein the second plate reference axis is parallel to the pin hole central axis.

20. The piston head assembly according to claim 14, wherein the first plate reference axis is parallel to the skirt reference axis.

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