Dual-fuel engine piston and engine

Abstract

The invention relates to the technical field of engines, and provides a dual-fuel engine piston and an engine. The dual-fuel engine piston comprises a combustion chamber pit, an annular end face and a convex ridge. The combustion chamber pit is formed in the head of the piston, the inner side of the annular end face is connected with the outer side of the combustion chamber pit, and the inner surface of the combustion chamber pit is a smooth curved surface; the multiple convex ridges are sequentially arranged at intervals in the circumferential direction of the inner surface of the combustion chamber pit, and each convex ridge is provided with a smooth curved surface. According to the dual-fuel engine piston, collision of adjacent jet flows is avoided so as to reduce kinetic energy loss, the strength of the jet flows in a combustion chamber is further enhanced, mixing of gas fuel and liquid fuel is enhanced, combustion is accelerated, and the combustion effect is improved.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and more particularly to a dual-fuel engine piston and engine. Background Technology

[0002] With the diversification of the global energy structure and increasingly stringent requirements for engine performance and emissions, dual-fuel engines are attracting more and more attention. A dual-fuel engine is an internal combustion engine that can use two different fuels simultaneously or alternately, typically combining traditional liquid fuels (such as diesel and gasoline) with clean gaseous fuels (such as natural gas, liquefied petroleum gas LPG, hydrogen, etc.), thereby improving energy flexibility while reducing emissions.

[0003] The fuel injection device located at the top of the combustion chamber injects a high-pressure jet toward the burner. The high-pressure jet contacts the combustion chamber wall, and adjacent jets are prone to collision, which reduces the jet velocity and causes kinetic energy loss, affecting the uniformity of fuel-air mixing and combustion speed. Summary of the Invention

[0004] This invention provides a dual-fuel engine piston and engine to solve the problem in the prior art where the combustion chamber formed by the piston easily causes fuel jet collision, affecting the uniformity of fuel-air mixing and combustion speed.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, the present invention provides a dual-fuel engine piston, comprising: a combustion chamber recess, an annular end face, and a convex ridge; The combustion chamber recess is located at the head of the piston, the inner side of the annular end face is connected to the outer side of the combustion chamber recess, and the inner surface of the combustion chamber recess is a smooth curved surface. The ridges are provided in multiples, and the multiple ridges are arranged sequentially at intervals around the inner surface of the combustion chamber recess. The ridges have smooth curved surfaces.

[0006] According to a dual-fuel engine piston provided by the present invention, the ridge includes a blocking strip and a transition strip; The blocking strip extends radially along the combustion chamber recess, the transition strip is arranged side by side with the blocking strip, and two transition strips are sandwiched between the two sides of each blocking strip; Both the blocking strip and the transition strip have smooth curved surfaces.

[0007] According to the present invention, in a dual-fuel engine piston, the two transition bars are arranged in parallel.

[0008] According to the present invention, a dual-fuel engine piston has a plurality of convex ridges uniformly arranged circumferentially around the inner surface of the combustion chamber recess.

[0009] According to a dual-fuel engine piston provided by the present invention, the inner surface of the combustion chamber recess is a maximum speed curve, which is generated by the cycloidal equation.

[0010] According to a dual-fuel engine piston provided by the present invention, the radius of the swing circle of the maximum speed curve is 0.075 to 0.15 times the piston diameter; And / or, the distance from the bottom of the fastest curve to the annular end face is 0.19 to 0.38 times the piston diameter.

[0011] A dual-fuel engine piston according to the present invention further includes: a swirl section; The flow section is located between the combustion chamber recess and the annular end face, and the flow section includes a first arc section and a horizontal section; One end of the first arc segment is connected to the annular end face, and the other end is connected to the first end of the horizontal segment. The second end of the horizontal segment is connected to the combustion chamber recess.

[0012] According to a dual-fuel engine piston provided by the present invention, the distance between the horizontal section and the annular end face is 0.02 to 0.04 times the piston diameter; And / or, the radius of the first arc segment is 0.1 to 0.2 times the diameter of the piston.

[0013] According to a dual-fuel engine piston provided by the present invention, the swirling section and the combustion chamber recess are connected by a second arc segment, wherein the radius of the second arc segment is 0.02 to 0.04 times the piston diameter; And / or, the convection section is connected to the annular end face via a third arc segment, the radius of which is 0.01 to 0.04 times the diameter of the piston.

[0014] In a second aspect, the present invention provides an engine comprising: a cylinder block, a cylinder head, and a dual-fuel engine piston as described above; The cylinder head is equipped with an intake valve, an exhaust valve, and a fuel injection device; The cylinder head is pressed onto the cylinder block, and the piston is movably disposed on the cylinder block. The cylinder head, the cylinder block, and the head of the piston form a combustion chamber. The intake valve, the exhaust valve, and the fuel injection device pass through the cylinder head and extend into the combustion chamber.

[0015] The dual-fuel engine piston and engine provided by this invention, by setting a combustion chamber recess and an annular end face at the head of the piston, and by setting multiple convex ridges circumferentially on the inner surface of the combustion chamber recess, and the convex ridges having smooth curved surfaces, so that when multiple jets are injected into the top of the combustion chamber, adjacent jets are blocked by the middle convex ridge when they are sprayed toward the inner surface of the combustion chamber recess, avoiding collisions between adjacent jets and reducing kinetic energy loss. In addition, the smooth curved surfaces of the convex ridges can also guide the jets toward the center of the combustion chamber, further enhancing the intensity of the jets in the combustion chamber, strengthening the mixing of gaseous fuel and liquid fuel, accelerating combustion, and improving combustion efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a three-dimensional structural diagram of the piston provided by the present invention.

[0018] Figure 2 This is a top view schematic diagram of the piston structure provided by the present invention.

[0019] Figure 3 This is a schematic diagram of the parameters of the combustion chamber provided by the present invention.

[0020] Figure 4 This is one of the schematic diagrams of the flow path of the fuel jet in the combustion chamber provided by the present invention.

[0021] Figure 5 This is a schematic diagram of the steepest curve principle provided by the present invention.

[0022] Figure 6 This is the second schematic diagram of the flow path of the fuel jet in the combustion chamber provided by the present invention.

[0023] Figure 7 This is a cross-sectional structural schematic diagram of the engine provided by the present invention.

[0024] Figure label: 1. Piston; 11. Head; 12. Skirt; 111. Combustion chamber recess; 112. Annular end face; 113. Ridge; 114. Swirl section; 115. Second arc section; 116. Third arc section; 1131. Barrier strip; 1132. Transition strip; 1141. First arc section; 1142. Horizontal section; 2. Cylinder block; 3. Cylinder head; 4. Intake valve; 5. Exhaust valve; 6. Fuel injection system; A. Jet curve moving towards the ridge; B. Jet curve moving towards the piston top; C. Jet curve moving in the swirling section; D. Jet blocked by the cylinder head; E. Jet moving towards the combustion chamber recess. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0026] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of clarifying the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0028] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0029] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0030] The following is combined Figures 1 to 7 The present invention will provide a detailed description of the dual-fuel engine piston and engine provided in the embodiments of the present invention through specific implementation methods and application scenarios.

[0031] Firstly, such as Figure 1 and Figure 2 As shown, this embodiment provides a dual-fuel engine piston 1, including: a combustion chamber recess 111, an annular end face 112, and a ridge 113.

[0032] The combustion chamber recess 111 is located at the head 11 of the piston 1. The inner side of the annular end face 112 is connected to the outer side of the combustion chamber recess 111. The inner surface of the combustion chamber recess 111 is a smooth curved surface.

[0033] Multiple ridges 113 are provided, and the multiple ridges 113 are arranged circumferentially around the inner surface of the combustion chamber recess 111. The ridges 113 have smooth curved surfaces.

[0034] Understandably, a dual-fuel engine typically refers to a gaseous fuel and a liquid fuel, with the liquid fuel being injected into the combustion chamber from the fuel injection device 6 in the middle of the cylinder head 3.

[0035] The piston 1 of a dual-fuel engine typically consists of a head 11 and a skirt 12. The head 11 faces the cylinder head 3, and the combustion chamber recess 111 of the head 11 forms a combustion chamber with the enclosed space of the cylinder head 3 and the cylinder block 2. The head 11 and the skirt 12 are welded together, and the side of the skirt 12 is provided with mounting holes for mounting piston pins and connecting rods, and for connecting to the crankshaft.

[0036] The head 11 of piston 1 is recessed inward to form a combustion chamber recess 111. The inner surface of the recess is used to guide the jet to move towards the top, bottom and sides of the combustion chamber during combustion. The combustion chamber recess 111 is a smooth curved surface, which is conducive to the discharge of residual exhaust gas from the combustion chamber during the intake process, thereby reducing the surface temperature of the combustion chamber, avoiding the formation of hot spots on the surface of the combustion chamber, and thus reducing the risk of knocking.

[0037] The fuel injection device 6 injects fuel into the combustion chamber, and the resulting jets are distributed circumferentially along the surface of the combustion chamber recess 111. Ridges 113 are positioned between adjacent jets, isolating them to prevent kinetic energy loss due to impact. Because the surface of the ridges 113 has a smooth curve, it also guides the contacting jets towards the center of the combustion chamber. Since the jet impact point is located on the surface of the combustion chamber recess 111 between adjacent ridges 113, the jets, guided by the surface of the recesses 111, move partly towards the top and bottom of the combustion chamber, and partly towards the ridges 113 on both sides. The edges of the ridges 113 are connected to the surface of the combustion chamber recess 111 through smooth curves, further reducing impact kinetic energy loss, thereby increasing the turbulence intensity of the combustion chamber, improving the mixing uniformity of liquid and gaseous fuels, and increasing the combustion speed.

[0038] like Figure 4 As shown, A represents the jet curve moving towards the ridge 113, and B represents the jet curve moving towards the top of the piston 1. The two jets moving towards the same ridge 113 are blocked by the sidewall of the ridge 113, causing their paths to change direction. Guided by the sidewall of the ridge 113, the two jets change direction and flow towards the center of the combustion chamber recess 111. This avoids collisions between adjacent jets and enhances jet turbulence within the combustion chamber, thus improving combustion efficiency. Furthermore, the jet moving towards the top of the piston 1 and the jet that changes direction upon encountering the ridge 113 rise in the combustion chamber recess 111 and accelerates jet turbulence, increasing the airflow velocity in the combustion chamber and enhancing the mixing of liquid and gaseous fuels.

[0039] Specifically, the number of ridges 113 ranges from 4 to 12.

[0040] The dual-fuel engine piston 1 provided by the present invention has a combustion chamber recess 111 and an annular end face 112 provided at the head 11 of the piston 1, and multiple ridges 113 are provided circumferentially on the inner surface of the combustion chamber recess 111. The ridges 113 have smooth curved surfaces, so that when multiple jets are injected into the top of the combustion chamber, adjacent jets are blocked by the middle ridge 113 when they are sprayed toward the inner surface of the combustion chamber recess 111, avoiding collision between adjacent jets and reducing kinetic energy loss. In addition, the smooth curved surfaces of the ridges 113 can also guide the jets toward the center of the combustion chamber, further enhancing the intensity of the jets in the combustion chamber, strengthening the mixing of gaseous fuel and liquid fuel, accelerating combustion, and improving the combustion effect.

[0041] like Figure 2 As shown, the ridge 113 in this embodiment includes a blocking strip 1131 and a transition strip 1132.

[0042] The blocking strip 1131 extends radially along the combustion chamber recess 111, and the transition strip 1132 is arranged side by side with the blocking strip 1131. Two transition strips 1132 are sandwiched on both sides of each blocking strip 1131.

[0043] Both the blocking strip 1131 and the transition strip 1132 have smooth curved surfaces.

[0044] Understandably, the transition strip 1132 serves as a smooth transition connection between the blocking strip 1131 and the surface of the burner recess, ensuring that the jet's impact point on the ridge 113 is always a smooth contact. This prevents the jet from encountering sharp or abrupt surfaces that could cause abrupt changes in velocity gradient, increasing flow resistance and creating localized pressure fluctuations that affect combustion stability. The transition strip 1132 gradually guides the jet's direction, maintaining the continuity of the jet flow, preventing concentrated jet impacts that could form localized hot spots, and reducing thermal stress concentration.

[0045] like Figure 2 As shown, the two transition bars 1132 in this embodiment are arranged in parallel.

[0046] Understandably, the smooth and parallel outer walls of the two transition strips 1132 allow adjacent jets to turn at relatively parallel angles when they hit the outer walls of the transition strips 1132, thus preventing adjacent jets from continuing to collide after turning, avoiding interference between adjacent jets, further reducing impact kinetic energy loss, and improving the uniformity of oil-gas mixing.

[0047] like Figure 1 and Figure 2 As shown, in this embodiment, multiple ridges 113 are uniformly arranged circumferentially around the inner surface of the combustion chamber recess 111.

[0048] Understandably, the uniform arrangement of multiple ridges 113 allows the turbulence effect of the inner surface of the burner recess on the jet to be uniformly distributed along the center of the combustion chamber recess 111. Since the jet injected by the fuel injection device 6 toward the combustion chamber is also uniformly distributed along the center of the combustion chamber, the obstruction and guidance of multiple jets by the multiple ridges 113 can also be uniformly distributed, thereby making the turning path of the jet in the combustion chamber uniformly distributed, improving the uniformity of the jet in the combustion chamber, and strengthening the jet turbulence.

[0049] like Figure 1 and Figure 5 As shown, the inner surface of the combustion chamber recess 111 in this embodiment is a speed curve, which is generated by the cycloidal equation.

[0050] Understandably, the brachistochrone curve is a cycloid, which is the trajectory of a circle at a certain point on the boundary of the circle when the circle moves along a straight line.

[0051] The brachistochrone curve segment is generated by the following system of equations, and the coordinates (x, y) of the brachistochrone curve satisfy the following cycloid equation: x = R × (θ / 180 × π - sinθ); y = R × (1 - cosθ); Where R is the radius of the pendulum circle, and θ is the angle of the circle's roll (0°≤θ≤360°).

[0052] like Figure 5 As shown in the figure, both the speed limit curve and the circular arc curve are displayed. Point P represents the trajectory of the speed limit curve. The starting point and ending point of the speed limit curve are steeper than those of the circular arc curve. The average velocity of the jet is fastest on the speed limit curve. Therefore, compared to the circular arc curve, the speed limit curve can further increase the velocity of the airflow along the combustion chamber wall during the intake process, which helps to reduce the surface temperature of piston 1 and reduce the risk of engine knock. At the same time, the smooth curved surface helps to remove residual exhaust gas from the combustion chamber during the overlapping period of intake valve 4 and exhaust valve 5. The residual exhaust gas on the wall heats the combustion chamber gas, which helps to improve the combustion chamber volumetric efficiency.

[0053] The fastest curve ensures that the resistance of the gas moving along the combustion chamber wall through the intake valve 4 during the intake process is minimized. This further increases the average speed of the airflow along the combustion chamber wall during the intake process, increases the intensity of turbulence in the combustion chamber, reduces kinetic energy dissipation, and helps the gas to quickly remove heat from the piston 1 surface, thereby reducing the surface temperature of the piston 1 and reducing the risk of knocking in the gas engine.

[0054] like Figure 6 As shown, D is the jet blocked by the cylinder head 3, and E is the jet moving towards the combustion chamber recess 111. Among them, the jet that is directed towards the inner surface of the combustion chamber recess 111 is guided by the inner surface of the fastest curve, one path is reflected downward by the combustion chamber recess 111, and the other path is blocked upward by the cylinder head 3.

[0055] like Figure 3 As shown, the radius of the swing circle of the fastest curve in this embodiment is 0.075 to 0.15 times the diameter of piston 1.

[0056] Understandably, such as Figure 3 As shown, D0 is the diameter of piston 1.

[0057] Optionally, the radius of the pendulum of the steepest curve is 0.075 times the diameter of piston 1, or it can be 0.1125 times, or it can be 0.15 times.

[0058] like Figure 3 As shown, in this embodiment, the distance from the bottom of the fastest curve to the annular end face 112 is 0.19 to 0.38 times the diameter of the piston 1.

[0059] Understandably, the distance from the bottom of the steepest curve to the annular end face 112 is h1.

[0060] Optionally, the distance from the bottom of the fastest curve to the annular end face 112 is 0.19 times the diameter of piston 1, or it can be 0.285 times or 0.38 times.

[0061] like Figure 1 and Figure 2 As shown, the dual-fuel engine piston 1 in this embodiment also includes a swirl section 114.

[0062] The swirling section 114 is located between the combustion chamber recess 111 and the annular end face 112. The swirling section 114 includes a first arc section 1141 and a horizontal section 1142.

[0063] One end of the first arc segment 1141 is connected to the annular end face 112, and the other end is connected to the first end of the horizontal segment 1142. The second end of the horizontal segment 1142 is connected to the combustion chamber recess 111.

[0064] Understandably, there is a compression clearance between the piston head 11 and the cylinder head 3. Due to manufacturing errors, the piston head 11 cannot directly contact the cylinder head 3, and gas exists in the compression clearance. The jet reflected by the cylinder head 3 can be reflected by the first arc segment 1141, changing its flow direction and flowing along the horizontal segment 1142, forming a vortex to increase the airflow disturbance in the compression clearance. This causes the jet to form a vortex effect in the vortex segment 114, which fully improves the diffusion and mixing of the jet, increases the air utilization rate of the top of the combustion chamber and the compression clearance, increases the turbulence intensity of the compression clearance, further improves emissions and combustion efficiency, and reduces the generation of unburned fuel and emission pollutants.

[0065] like Figure 3 As shown, the diameter of the convection section 114 is D1. D2 is twice the distance from the starting point of the steepest curve to the central axis.

[0066] Specifically, after the jet collides with the surface of the combustion chamber recess 111, a portion of the jet moves towards the top of the combustion chamber and is blocked by the bottom surface of the cylinder head 3, such as... Figure 6 As shown, C is the jet curve of the jet moving in the vortex section 114, where part of the jet moves towards the vortex region and the other part moves towards the center of the combustion chamber.

[0067] like Figure 3 As shown, in this embodiment, the distance between the horizontal segment 1142 and the annular end face 112 is 0.02 to 0.04 times the diameter of the piston 1.

[0068] Understandably, such as Figure 3 As shown, the distance between the horizontal segment 1142 and the annular end face 112 is h2.

[0069] Optionally, the distance between the horizontal segment 1142 and the annular end face 112 is 0.02 times the diameter of the piston 1, or it can be 0.03 times or 0.04 times.

[0070] like Figure 1 and Figure 2 As shown, the radius of the first arc segment 1141 in this embodiment is 0.1 to 0.2 times the diameter of the piston 1.

[0071] Understandably, such as Figure 3 As shown, the radius of the first arc segment 1141 is R3.

[0072] Optionally, the radius of the first arc segment 1141 is 0.1 times the diameter of the piston 1, or it can be 0.15 times or 0.2 times.

[0073] like Figure 1 and Figure 2 As shown, in this embodiment, the swirl section 114 and the combustion chamber recess 111 are connected by a second arc section 115, and the radius of the second arc section 115 is 0.02 to 0.04 times the diameter of the piston 1.

[0074] Understandably, such as Figure 3 As shown, the radius of the second arc segment 115 is R2.

[0075] Optionally, the radius of the second arc segment 115 is 0.02 times the diameter of the piston 1, or it can be 0.03 times or 0.04 times.

[0076] like Figure 1 and Figure 2 As shown, in this embodiment, the convection section 114 and the annular end face 112 are connected by a third arc section 116, and the radius of the arc of the third arc section 116 is 0.01 to 0.04 times the diameter of the piston 1.

[0077] Understandably, such as Figure 3 As shown, the radius of the third arc segment 116 is R1. The swirling section 114 and the annular end face 112 transition smoothly through the third arc. No constriction is provided here. This facilitates the removal of residual exhaust gas from the combustion chamber during the valve overlap period, preventing the residual exhaust gas from heating the combustion chamber gases, thus further improving the combustion chamber charge coefficient. On the other hand, it reduces turbulent dissipation in the combustion chamber during the compression process, allowing the intake vortex to be maintained for a longer period, thereby improving the flame propagation speed after ignition and reducing cycle fluctuations.

[0078] Optionally, the radius of the third arc segment 116 is 0.01 times the diameter of the piston 1, or it can be 0.025 times, or it can be 0.04 times.

[0079] Furthermore, since the combustion chamber does not have a constriction structure, the piston head 11 can be machined by precision forging, eliminating the need for machining and thus reducing production costs and processing difficulty.

[0080] Forging draft analysis of piston head 11 shows that piston 1 can be pulled out of the mold after forging.

[0081] Secondly, such as Figure 7 As shown, this embodiment provides an engine, including: a cylinder block 2, a cylinder head 3, and a dual-fuel engine piston 1 as described above.

[0082] The cylinder head 3 is equipped with an intake valve 4, an exhaust valve 5, and a fuel injection device 6.

[0083] The cylinder head 3 is pressed onto the cylinder block 2, and the piston 1 is movably disposed on the cylinder block 2. The cylinder head 3, the cylinder block 2, and the head 11 of the piston 1 form a combustion chamber.

[0084] The intake valve 4, the exhaust valve 5, and the fuel injection device 6 pass through the cylinder head 3 and extend into the combustion chamber.

[0085] Specifically, since the engine includes a dual-fuel engine piston 1, and the specific structure of the dual-fuel engine piston 1 is as described in the above embodiments, the engine shown in this embodiment includes all the technical solutions of the above embodiments. Therefore, it has at least all the beneficial effects achieved by all the technical solutions of the above embodiments, which will not be described in detail here.

[0086] It is understood that a dual-fuel engine typically refers to a gaseous fuel and a liquid fuel. In this embodiment, the liquid fuel is injected into the combustion chamber from the fuel injection device 6, and the gaseous fuel enters the combustion chamber from the intake valve 4 and exits the combustion chamber from the exhaust valve 5.

[0087] The intake valve 4 and exhaust valve are movable relative to the cylinder head 3 to control the opening and closing of the intake and exhaust passages. The portion of the fuel injection device 6 extending into the combustion chamber is capable of injecting liquid fuel, and injects it uniformly circumferentially along the center of the combustion chamber.

[0088] Piston 1 is pushed toward cylinder head 3. The combustion chamber recess 111 of piston head 11 and cylinder head 3 form a closed combustion chamber. Liquid fuel is burned in the combustion chamber, further igniting gas fuel. Gas fuel and liquid fuel are burned in the combustion chamber to do work.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dual-fuel engine piston, characterized in that, include: Combustion chamber recesses, annular end faces, and convex ridges; The combustion chamber recess is located at the head of the piston, the inner side of the annular end face is connected to the outer side of the combustion chamber recess, and the inner surface of the combustion chamber recess is a smooth curved surface. The ridges are provided in multiples, and the multiple ridges are arranged sequentially at intervals around the inner surface of the combustion chamber recess. The ridges have smooth curved surfaces.

2. The dual-fuel engine piston according to claim 1, characterized in that, The ridge includes a blocking strip and a transition strip; The blocking strip extends radially along the combustion chamber recess, the transition strip is arranged side by side with the blocking strip, and two transition strips are sandwiched between the two sides of each blocking strip; Both the blocking strip and the transition strip have smooth curved surfaces.

3. The dual-fuel engine piston according to claim 2, characterized in that, The two transition bars are set in parallel.

4. The dual-fuel engine piston according to claim 1, characterized in that, The plurality of the convex ridges are uniformly arranged circumferentially around the inner surface of the combustion chamber recess.

5. The dual-fuel engine piston according to claim 1, characterized in that, The inner surface of the combustion chamber recess is a steepest curve, which is generated by the cycloidal equation.

6. The dual-fuel engine piston according to claim 5, characterized in that, The radius of the swing circle of the fastest curve is 0.075 to 0.15 times the diameter of the piston; And / or, the distance from the bottom of the fastest curve to the annular end face is 0.19 to 0.38 times the piston diameter.

7. The dual-fuel engine piston according to claim 1, characterized in that, Also includes: Volume Flow section; The flow section is located between the combustion chamber recess and the annular end face, and the flow section includes a first arc section and a horizontal section; One end of the first arc segment is connected to the annular end face, and the other end is connected to the first end of the horizontal segment. The second end of the horizontal segment is connected to the combustion chamber recess.

8. The dual-fuel engine piston according to claim 7, characterized in that, The distance between the horizontal segment and the annular end face is 0.02 to 0.04 times the diameter of the piston; And / or, the radius of the first arc segment is 0.1 to 0.2 times the diameter of the piston.

9. The dual-fuel engine piston according to claim 8, characterized in that, The swirling section is connected to the combustion chamber recess by a second arc segment, the radius of which is 0.02 to 0.04 times the piston diameter. And / or, the convection section is connected to the annular end face via a third arc segment, the radius of which is 0.01 to 0.04 times the diameter of the piston.

10. An engine, characterized in that, include: Cylinder block, cylinder head, and dual-fuel engine piston as described in any one of claims 1 to 9; The cylinder head is equipped with an intake valve, an exhaust valve, and a fuel injection device; The cylinder head is pressed onto the cylinder block, and the piston is movably disposed on the cylinder block. The cylinder head, the cylinder block, and the head of the piston form a combustion chamber. The intake valve, the exhaust valve, and the fuel injection device pass through the cylinder head and extend into the combustion chamber.

Images