Engine combustion system
By designing a recessed structure and an oil guide section in the combustion chamber of the opposed piston engine, the problem of uneven fuel spray diffusion was solved, achieving uniform mixing and improved air utilization in the combustion chamber, thus improving combustion performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- TIANJIN UNIV
- Filing Date
- 2025-01-15
- Publication Date
- 2026-05-19
AI Technical Summary
In existing opposed piston engines, the fuel injectors in the combustion chamber can only be arranged radially along the cylinder, which leads to an increase in the fuel spray diffusion and mixing distance, low air utilization, uneven fuel-air mixture distribution, and poor combustion performance.
The design incorporates recessed structures on the first and second pistons, which, in conjunction with the injector, guide the fuel to be evenly distributed within the combustion chamber. The design of the fuel guide section ensures that the fuel flows along a specific path, guaranteeing uniform distribution.
It improves the air utilization rate in the combustion chamber, enhances the fuel-air mixing characteristics, and improves combustion performance.
Smart Images
Figure CN119825592B_ABST
Abstract
Description
Technical Field
[0001] At least one embodiment of the present invention relates to the field of internal combustion engine technology, and particularly to an engine combustion system. Background Technology
[0002] In an opposed-piston engine combustion system, the two pistons are symmetrically positioned on either side of the crankshaft and move horizontally towards or away from each other, resulting in better balance. The overall height and length of this combustion system are low, which lowers the vehicle's center of gravity and makes driving more stable. During operation, the torque generated by the two pistons on either side cancels each other out, significantly reducing vibration during vehicle operation.
[0003] However, existing opposed piston engines mainly use a spatially symmetrical combined combustion chamber, meaning that the fuel-containing areas of the intake and exhaust pistons have basically the same shape. Due to the structure of the opposed piston arrangement, the injectors can only be arranged radially along the cylinder, which leads to an increase in the spray diffusion and mixing distance in the combustion chamber, low air utilization, uneven fuel-air mixture distribution, and poor combustion performance. Summary of the Invention
[0004] In view of this, the present invention provides an engine combustion system that makes the fuel injected into the combustion chamber by the injector evenly dispersed inside the combustion chamber.
[0005] According to an embodiment of the present invention, an engine combustion system is provided, comprising: a cylinder block; a first piston movably mounted inside the cylinder block, wherein a first recess is formed at one end of the first piston extending in an axial direction; a second piston movably mounted inside the cylinder block and disposed facing the first piston, wherein a second recess is formed at the end of the second piston facing the first recess, the first recess, the second recess, and the cylinder block forming a combustion chamber; and a fuel injector mounted on the cylinder block, adapted to inject fuel toward the interior of the combustion chamber; wherein the first recess is configured to guide fuel to flow toward the inner wall of the combustion chamber near the fuel injector side when the first piston and the second piston are in contact; the second recess is configured to guide fuel to flow toward the inner wall of the combustion chamber near the fuel injector side and toward the inner wall of the combustion chamber facing the fuel injector side when the first piston and the second piston are in contact, such that the fuel is uniformly distributed inside the combustion chamber.
[0006] According to an embodiment of the present invention, the inner wall of the first recess facing the injector includes a first oil guide section, a second oil guide section, and a third oil guide section that are smoothly connected in sequence. The first oil guide section and the third oil guide section are both recessed toward the side away from the injector, and the second oil guide section is protruding toward the side facing the injector, so that after the fuel sprayed from the injector hits the second oil guide section, it flows along the first oil guide section and the third oil guide section toward the inner wall of the first recess near the injector.
[0007] According to an embodiment of the present invention, the first oil guide section, the second oil guide section and the third oil guide section are all constructed in a generally arc shape.
[0008] According to an embodiment of the present invention, the projection of the middle part of the arc of the second oil guide section in the axial direction falls on the radial line connecting the cross sections of the first piston, and the first oil guide section and the third oil guide section are symmetrically arranged about the second oil guide section.
[0009] According to an embodiment of the present invention, the inner wall of the first recess near the injector is constructed to be generally arc-shaped, and both ends are smoothly connected to the first oil guide section and the third oil guide section, respectively.
[0010] According to an embodiment of the present invention, the inner wall of the second recess facing the injector includes a fourth oil guide section, a fifth oil guide section, and a sixth oil guide section that are smoothly connected in sequence. The fourth oil guide section and the sixth oil guide section both protrude towards the side facing the injector, and the fifth oil guide section is recessed towards the side away from the injector, so that after the fuel sprayed from the injector hits the fourth oil guide section or the sixth oil guide section, it flows along the fourth oil guide section or the sixth oil guide section towards the inner wall of the second recess near the injector and the fifth oil guide section, respectively.
[0011] According to an embodiment of the present invention, the fourth oil guide section, the fifth oil guide section, and the sixth oil guide section are all constructed in a generally arc shape.
[0012] According to an embodiment of the present invention, the projection of the middle part of the arc of the fifth oil guide section in the axial direction falls on the radial line connecting the cross sections of the second piston, and the fourth guide section and the sixth guide section are symmetrically arranged about the fifth guide section.
[0013] According to an embodiment of the present invention, the inner wall of the second recess near the injector is constructed to be generally arc-shaped, and both ends are smoothly connected to the fourth oil guide section and the sixth oil guide section, respectively.
[0014] According to an embodiment of the present invention, the first recess and the second recess are respectively formed with mutually compatible notches, which are suitable for guiding the fuel injected by the injector into the interior of the first recess and the second recess when the first piston and the second piston are in contact.
[0015] According to the engine combustion system of the above embodiment of the present invention, a first recess is formed at one end of the first piston extending in the axial direction, and a second recess is formed at the end of the second piston facing the first recess. The first recess, the second recess, and the cylinder block form a combustion chamber. The first recess is configured to guide fuel to flow toward the inner wall of the combustion chamber near the injector side when the first piston and the second piston are in contact. The second recess is configured to guide fuel to flow toward the inner wall of the combustion chamber near the injector side and toward the inner wall of the combustion chamber facing the injector side when the first piston and the second piston are in contact, respectively, so that the fuel is evenly distributed inside the combustion chamber. Attached Figure Description
[0016] Figure 1 This is a cross-sectional view of the engine combustion system according to an embodiment of the present invention;
[0017] Figure 2 This is a three-dimensional schematic diagram of the fuel injector injecting fuel into the first piston in the engine combustion system according to an embodiment of the present invention;
[0018] Figure 3 This is a three-dimensional schematic diagram of the fuel injector injecting fuel into the second piston in the engine combustion system according to an embodiment of the present invention;
[0019] Figure 4 This is a schematic diagram of the fuel injection circuit of the engine combustion system according to an embodiment of the present invention, showing the fuel injector injecting fuel into the first piston; and
[0020] Figure 5 This is a schematic diagram of the oil circuit of the engine combustion system according to an embodiment of the present invention, showing the injector injecting oil into the second piston.
[0021] In the picture:
[0022] 1-Cylinder block;
[0023] 2-First piston; 21-First recess; 211-First oil guide section; 212-Second oil guide section; 213-Third oil guide section; 214-Notch;
[0024] 3-Second piston; 31-Second recess; 311-Fourth oil guide section; 312-Fifth oil guide section; 313-Sixth oil guide section;
[0025] 4-Combustion chamber;
[0026] 5-Injector; 51-Middle oil jet; 52-Outer oil jet. Detailed Implementation
[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.
[0028] According to one aspect of the inventive concept of the present invention, an engine combustion system is provided, comprising: a cylinder block; a first piston movably mounted inside the cylinder block, wherein a first recess is formed at one end of the first piston extending in an axial direction; a second piston movably mounted inside the cylinder block and disposed facing the first piston, wherein a second recess is formed at the end of the second piston facing the first recess, the first recess, the second recess, and the cylinder block forming a combustion chamber; and a fuel injector mounted on the cylinder block, adapted to inject fuel toward the interior of the combustion chamber; wherein the first recess is configured to guide fuel to flow toward the inner wall of the combustion chamber near the fuel injector side when the first piston and the second piston are in contact; the second recess is configured to guide fuel to flow toward the inner wall of the combustion chamber near the fuel injector side and toward the inner wall of the combustion chamber facing the fuel injector side when the first piston and the second piston are in contact, thereby uniformly dispersing fuel inside the combustion chamber.
[0029] Figure 1 This is a cross-sectional view of the engine combustion system according to an embodiment of the present invention; Figure 2 This is a three-dimensional schematic diagram of the fuel injector injecting fuel into the first piston in the engine combustion system according to an embodiment of the present invention; Figure 3 This is a three-dimensional schematic diagram of the fuel injector injecting fuel into the second piston of the engine combustion system according to an embodiment of the present invention.
[0030] According to an exemplary embodiment of the present invention, please refer to Figures 1-3 An engine combustion system is provided, including a cylinder block 1, a first piston 2, a second piston 3, and a fuel injector 5. The first piston 2 is movably mounted inside the cylinder block 1, and a first recess 21 is formed at one end of the first piston 2 extending axially. The second piston 3 is movably mounted inside the cylinder block 1, facing the first piston 2, and a second recess 31 is formed at the end of the second piston 3 facing the first recess 21. The first recess 21, the second recess 31, and the cylinder block 1 form a combustion chamber 4. The fuel injector 5 is mounted on the cylinder block 1 and is adapted to inject fuel into the combustion chamber 4. The first recess 21 is configured to guide fuel to flow towards the inner wall 41 of the combustion chamber 4 near the fuel injector 5 when the first piston 2 and the second piston 3 are in contact. The second recess 31 is configured to guide fuel to flow towards the inner wall of the combustion chamber 4 near the fuel injector 5 and towards the inner wall of the combustion chamber 4 facing the fuel injector 5, respectively, when the first piston 2 and the second piston 3 are in contact, so that the fuel is evenly distributed inside the combustion chamber 4.
[0031] In this embodiment, a first recess 21 is formed at one end of the first piston 2 extending in the axial direction, and a second recess 31 is formed at the end of the second piston 3 facing the first recess 21. The first recess 21, the second recess 31, and the cylinder block 1 form a combustion chamber 4. The first recess 21 is configured to guide fuel to flow toward the inner wall of the combustion chamber 4 near the injector 5 when the first piston 2 and the second piston 3 are in contact. The second recess 31 is configured to guide fuel to flow toward the inner wall of the combustion chamber 4 near the injector 5 and toward the inner wall of the combustion chamber 4 facing the injector 5 when the first piston 2 and the second piston 3 are in contact, so that the fuel is evenly distributed inside the combustion chamber 4.
[0032] Figure 4 This is a schematic diagram of the oil circuit of the engine combustion system according to an embodiment of the present invention, showing the injector injecting oil into the first piston.
[0033] In some exemplary embodiments, reference is made to Figure 4 The inner wall of the first recess 21 facing the injector 5 includes a first oil guide section 211, a second oil guide section 212, and a third oil guide section 213 connected smoothly in sequence. The first oil guide section 211 and the third oil guide section 213 are both recessed towards the side away from the injector 5, while the second oil guide section 212 protrudes towards the side facing the injector 5. This allows the fuel ejected from the injector 5 to flow along the inner wall of the first recess 21 towards the side of the first recess 21 near the injector 5 after impacting the second oil guide section 212.
[0034] In this embodiment, after the fuel injected by the injector 5 impacts the second oil guide section 212, it flows along the inner wall of the first oil guide section 211 and the third oil guide section 213 toward the side of the first recess 21 near the injector 5. Figure 4 The middle arrows A and B indicate the flow direction of fuel inside the first recess 21, so that the fuel fills the side of the first recess 21 near the injector 5.
[0035] In some exemplary embodiments, reference is made to Figure 4 The first oil guide section 211, the second oil guide section 212 and the third oil guide section 213 are all constructed in a roughly circular arc shape.
[0036] By means of the above configuration, the fuel is guided to flow along the first oil guide section 211, the second oil guide section 212 and the third oil guide section 213 respectively, so that the fuel flows smoothly through the first oil guide section 211, the second oil guide section 212 and the third oil guide section 213.
[0037] In some exemplary embodiments, reference is made to Figure 4The projection of the middle part of the arc of the second oil guide section 212 in the axial direction falls on the radial line connecting the cross sections of the first piston 2. The first oil guide section 211 and the third oil guide section 213 are symmetrically arranged about the second oil guide section 212.
[0038] In this embodiment, by setting the projection of the middle part of the arc of the second oil guide section 212 in the axial direction onto the radial line connecting the cross sections of the first piston 2, the first oil guide section 211 and the third oil guide section 213 are symmetrically arranged about the second oil guide section 212 to guide the oil jet 51 sprayed from the injector 5 in the middle towards the inner wall of the first recess 21 near the injector 5. Figure 4 As shown by arrows A and B.
[0039] In other words, when the first piston 2 and the second piston 3 are in contact, the middle part of the arc of the injector 5 and the second oil guide section 212 face each other, so that the oil jet 51 sprayed by the injector 5 in the middle hits the second oil guide section 212 and flows along the first oil guide section 211 or the third oil guide section 213 toward the inner wall of the first pit 21 near the injector 5.
[0040] In some exemplary embodiments, reference is made to Figure 4 The inner wall of the first recess 21 near the injector 5 is constructed in a roughly arc shape, and its two ends are smoothly connected to the first oil guide section 211 and the third oil guide section 213, respectively.
[0041] The above configuration allows fuel to flow smoothly between the first oil guide section 211 and the side of the first recess 21 near the injector 5, or between the third oil guide section 213 and the side of the first recess 21 near the injector 5.
[0042] Figure 5 This is a schematic diagram of the oil circuit of the engine combustion system according to an embodiment of the present invention, showing the injector injecting oil into the second piston.
[0043] In some exemplary embodiments, reference is made to Figure 5 The inner wall of the second recess 31 facing the injector 5 includes a fourth oil guide section 311, a fifth oil guide section 312, and a sixth oil guide section 313 connected smoothly in sequence. The fourth oil guide section 311 and the sixth oil guide section 313 both protrude towards the side facing the injector 5, while the fifth oil guide section 312 is recessed towards the side away from the injector 5. This allows the fuel ejected from the injector 5 to flow along the fourth oil guide section 311 or the sixth oil guide section 313 towards the inner wall of the second recess 31 near the injector 5 and towards the fifth oil guide section 312 after impacting the fourth oil guide section 311 or the sixth oil guide section 313.
[0044] In this embodiment, after the fuel injected by the injector 5 impacts the fourth fuel guide section 311 or the sixth fuel guide section 313, it flows along the fourth fuel guide section 311 or the sixth fuel guide section 313 toward the inner wall of the second recess 31 near the injector 5 and the fifth fuel guide section 312, respectively. Figure 5 Arrows C, D, E, and F indicate the flow direction of fuel inside the second recess 31, so that most of the fuel fills the side of the second recess 31 facing the injector 5, and a small portion fills the side of the first recess 21 near the injector 5.
[0045] In some exemplary embodiments, reference is made to Figure 5 The fourth oil guide section 311, the fifth oil guide section 312, and the sixth oil guide section 313 are all constructed in a roughly circular arc shape.
[0046] By means of the above configuration, the fuel is guided to flow along the fourth oil guide section 311, the fifth oil guide section 312 and the sixth oil guide section 313 respectively, so that the fuel flows smoothly through the fourth oil guide section 311, the fifth oil guide section 312 and the sixth oil guide section 313.
[0047] In some exemplary embodiments, reference is made to Figure 5 The projection of the middle part of the arc of the fifth oil guide section 312 in the axial direction falls on the radial line connecting the cross sections of the second piston 3. The fourth guide section 311 and the sixth guide section 313 are symmetrically arranged about the fifth guide section 312.
[0048] In this embodiment, the fifth oil guide section 312 is configured such that the projection of the middle part of the arc of the fifth oil guide section 312 in the axial direction falls on the radial line connecting the cross sections of the second piston 3. The fourth guide section 311 and the sixth guide section 313 are symmetrically arranged about the fifth guide section 312 to guide the oil jet 52 sprayed by the injector 5 on the outer side to flow toward the inner wall of the second recess 31 near the injector 5. Figure 5 As indicated by arrows C and E, and the flow toward the fifth guide oil section 312, as shown... Figure 5 As indicated by arrows D and F.
[0049] In other words, when the first piston 2 and the second piston 3 are in contact, the middle part of the arc of the injector 5 and the fifth oil guide section 312 faces each other, so that the oil jet 52 sprayed by the injector 5 on the outer side hits the fifth oil guide section 312, and the oil jet 52 sprayed by the injector 5 on the outer side flows toward the inner wall of the second recess 31 near the injector 5 and the fifth oil guide section 312 respectively.
[0050] In some exemplary embodiments, reference is made to Figure 5The inner wall of the second recess 31 near the injector 5 is constructed in a roughly arc shape, and its two ends are smoothly connected to the fourth oil guide section 311 and the sixth oil guide section 313, respectively.
[0051] The above configuration allows fuel to flow smoothly between the fourth oil guide section 311 and the side of the second recess 31 near the injector 5, or between the sixth oil guide section 313 and the side of the second recess 31 near the injector 5.
[0052] In some exemplary embodiments, reference is made to Figures 4-5 The first recess 21 and the second recess 31 are respectively formed with matching notches 214, which are suitable for guiding the fuel injected by the injector 5 into the first recess 21 and the second recess 31 when the first piston 2 and the second piston 3 are in contact.
[0053] In this embodiment, mutually compatible notches 214 are formed on the first recess 21 and the second recess 31, so that when the first piston 2 and the second piston 3 are in contact, a flow channel is reserved for the fuel injected by the injector 5 to be injected into the combustion chamber 4, so as to guide the fuel injected by the injector 5 into the interior of the first recess 21 and the second recess 31.
[0054] The engine combustion system of this invention has the following advantages:
[0055] The first recess 21 formed on the first piston 2 and the second recess 31 formed on the second piston 3 cooperate with each other to form the combustion chamber 4 with the cylinder block 1. The cooperation between the first recess 21 and the second recess 31 guides the fuel flow, enhances the airflow movement of fuel near the wall of the combustion chamber 4, and changes the diffusion direction of fuel inside the combustion chamber 4, thereby improving the air utilization rate inside the combustion chamber 4 and making the distribution of combustible mixture inside the combustion chamber 4 more uniform, thus improving the fuel-air mixing characteristics.
[0056] Fuel injected by injector 5 enters the first recess 21. The central fuel jet 51 impacts the second fuel guide section 212. Under the diversion effect of the first fuel guide section 211 and the third fuel guide section 213, it mixes with air throughout the first recess 21. Fuel injected by injector 5 enters the second recess 31. The outer fuel jet 52, under the diversion effect of the fourth guide section 311 and the sixth fuel guide section 313, and guided by the fifth fuel guide section 312, mixes with air inside the second recess 31, improving the air utilization rate inside the combustion chamber 4. The engine combustion system of this invention, while maintaining a constant compression ratio, expands the fuel-air mixing area and guides the spatial distribution of the combustible mixture within the cylinder block 1 to become more uniform.
[0057] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. An engine combustion system, comprising: Cylinder block (1); A first piston (2) is movably installed inside the cylinder (1), and a first recess (21) is formed at one end of the first piston (2) extending in the axial direction; The second piston (3) is movably installed inside the cylinder (1) and is arranged facing the first piston (2). The second piston (3) has a second recess (31) formed at one end facing the first recess (21). The first recess (21), the second recess (31) and the cylinder (1) form a combustion chamber (4). as well as A fuel injector (5) is mounted on the cylinder block (1) and is adapted to inject fuel toward the interior of the combustion chamber (4); The inner wall of the first recess (21) facing the injector (5) includes a first oil guide section (211), a second oil guide section (212), and a third oil guide section (213) connected in sequence. The first oil guide section (211) and the third oil guide section (213) are both recessed towards the side away from the injector (5), and the second oil guide section (212) is protruding towards the side facing the injector (5). This allows the fuel sprayed from the injector (5) to flow along the inner wall of the first recess (211) and the third oil guide section (213) towards the side of the first recess (21) near the injector (5) after it hits the second oil guide section (212). The inner wall of the second recess (31) facing the injector (5) includes a fourth oil guide section (311), a fifth oil guide section (312), and a sixth oil guide section (313) connected smoothly in sequence. The fourth oil guide section (311) and the sixth oil guide section (313) both protrude towards the side facing the injector (5), and the fifth oil guide section (312) is recessed towards the side away from the injector (5). This allows the fuel sprayed from the injector (5) to flow along the fourth oil guide section (311) or the sixth oil guide section (313) towards the inner wall of the second recess (311) near the injector (5) and the fifth oil guide section (312) after it hits the fourth oil guide section (311) or the sixth oil guide section (313). The first recess (21) is configured to guide fuel toward the inner wall (41) of the combustion chamber (4) near the injector (5) when the first piston (2) and the second piston (3) are in contact; the second recess (31) is configured to guide fuel toward the inner wall of the combustion chamber (4) near the injector (5) and toward the inner wall of the combustion chamber (4) facing the injector (5) when the first piston (2) and the second piston (3) are in contact, so that the fuel is evenly distributed inside the combustion chamber (4).
2. The engine combustion system according to claim 1, wherein, The first oil guide section (211), the second oil guide section (212), and the third oil guide section (213) are all constructed in a generally arc shape.
3. The engine combustion system according to claim 2, wherein, The projection of the middle part of the arc of the second oil guide section (212) in the axial direction falls on the radial line connecting the cross sections of the first piston (2). The first oil guide section (211) and the third oil guide section (213) are symmetrically arranged about the second oil guide section (212).
4. The engine combustion system according to claim 2, wherein, The inner wall of the first recess (21) near the injector (5) is constructed in a generally arc shape, and its two ends are smoothly connected to the first oil guide section (211) and the third oil guide section (213) respectively.
5. The engine combustion system according to claim 1, wherein, The fourth oil guide section (311), the fifth oil guide section (312), and the sixth oil guide section (313) are all constructed in a generally arc shape.
6. The engine combustion system according to claim 5, wherein, The projection of the middle part of the arc of the fifth oil guide section (312) in the axial direction falls on the radial line connecting the cross sections of the second piston (3). The fourth oil guide section (311) and the sixth oil guide section (313) are symmetrically arranged about the fifth oil guide section (312).
7. The engine combustion system according to claim 5, wherein, The inner wall of the second recess (31) near the injector (5) is constructed in a generally arc shape, and its two ends are smoothly connected to the fourth oil guide section (311) and the sixth oil guide section (313) respectively.
8. The engine combustion system according to claim 1, wherein, The first recess (21) and the second recess (31) are respectively provided with matching notches (214) to guide the fuel injected by the injector (5) into the first recess (21) and the second recess (31) when the first piston (2) and the second piston (3) are in contact.