CN1302200C

CN1302200C - Combustion chamber

Info

Publication number: CN1302200C
Application number: CNB028184750A
Authority: CN
Inventors: Z·刘; X·贵
Original assignee: International Engine Intellectual Property Co LLC
Current assignee: International Engine Intellectual Property Co LLC
Priority date: 2001-07-23
Filing date: 2002-07-18
Publication date: 2007-02-28
Anticipated expiration: 2022-07-18
Also published as: MXPA04000642A; CA2454719A1; EP1409858A4; CN1556894A; WO2003010423A1; KR20040021645A; EP1409858A1; BR0211398A; JP2004536992A

Abstract

A combustion chamber assembly for use in a diesel engine includes a combustion chamber (14) being defined in a crown (12) of a piston (10), the piston (10) having a central axis (16, 18, 518, 524), the combustion chamber (14) having a center portion defining a post, the center portion being defined at least in part by a portion of a sphere, the sphere having a radius, the origin of the radius lying on the piston central axis (16, 18, 518, 524) and the combustion chamber (14) further having a plurality of curved surfaces having smooth tangential transitions between adjacent smooth surfaces, the smooth surfaces including the spherical center portion and at least one annular surface, the combustion chamber (14) being symmetrical with respect to a combustion chamber longitudinal axis (16, 216, 316, 416). A piston (10) incorporating the aforementioned combustion chamber (14) and a method of forming the combustion chamber (14) are further included.

Description

The firing chamber

Technical field

The present invention relates to a firing chamber, it is designed for the internal-combustion engine of an ignition by compression (diesel engine).Or rather, the present invention relates to a piston with the firing chamber that is formed on its top.

Background of invention

People have carried out multiple trial, in the hope of produce the desirable flow pattern be used for air and fuel-feed in the firing chamber of internal-combustion engine.The effect that must consider include but not limited to provide produce that the NOx that carries secretly in enough power, the engine exhaust minimizes and engine exhaust in the smokeshade amount of carrying secretly minimize.

As everyone knows, the multiple variable of engine design/operation injects spray pattern and other variable such as engine compression ratio, combustion-chamber shape, fuel, and the change meeting of its arbitrary variable is influential to the power of discharging and generation.

The fume amount of discharging in the engine exhaust is unbecoming, produces public pressure thus and requires to remove diesel engine.In addition, the fume amount that is entrained in the engine lubricating oil can have illeffects to engine reliability.The non-regular meeting of flue dust causes abrasion, thereby can cause the high wear of motor.

In addition, also have a large amount of pressure to require to reduce the NOx discharging of motor.The management rules of increasingly stringent have required constantly to issue that decree is to reduce the level of NOx.Normally, found a kind of Combustion chamber design to reduce the NOx level effectively and increased smoke levels, vice versa.In addition, make each aforesaid content and generally can reduce the output of engine torque and power.

Many examples that are formed on the firing chamber of piston head are arranged.Although the design of these prior aries is arranged, people still hold such demand: can reduce NOx and can reduce the flue dust of carrying secretly again, and keep simultaneously or raising engine torque and power output.

Brief summary of the invention

Piston of the present invention satisfies above-mentioned industrial requirement basically.The firing chamber that is formed on the piston head has demonstrated the discharging that reduces flue dust entrainment and Nox, meanwhile slightly increases engine power output.Piston has shown the cylinder head that is used to have two or more valves effectively.Another advantage of firing chamber of the present invention is: the firing chamber is with respect to the central axis symmetry of piston, and the firing chamber relatively easily forms at the top of piston.

The present invention is a kind of combustion-chamber assembly that is used for diesel engine, it comprises that one is formed on the firing chamber of piston head, piston has a central axis, this firing chamber has a core that forms a cylinder, core is formed by the part of a spheroid at least in part, this spheroid has a radius, the centre of sphere drops on the piston middle spindle line, and the firing chamber also has a plurality of curved surfaces with level and smooth tangent line transition between the adjacency smooth surface, smooth surface comprises spherical core and at least one ring surface, and the firing chamber is with respect to firing chamber longitudinal axis symmetry.The present invention comprises that also one has the piston of previous combustion chamber component and the method that forms the previous combustion chamber.

Brief description of drawings

Fig. 1 is the sectional view of piston of the present invention;

Fig. 2 is the diagram of comparison of the power of the power of prior art piston and firing chamber and piston of the present invention and firing chamber;

Fig. 3 is the diagram by the comparison of the NOx of the NOx of prior art piston and firing chamber generation and piston of the present invention and firing chamber generation;

Fig. 4 is the diagram by the comparison of the flue dust of the flue dust of prior art piston and firing chamber generation and piston of the present invention and firing chamber generation;

Fig. 5 is the sectional view of the piston of the second embodiment of the present invention;

Fig. 6 is the diagram of comparison of the power of the piston of the power of prior art piston and firing chamber and second embodiment of the invention and firing chamber;

Fig. 7 is the diagram by the comparison of the piston of the NOx of prior art piston and firing chamber generation and second embodiment of the invention and the NOx that the firing chamber produces;

Fig. 8 is the diagram by the comparison of the piston of the flue dust of prior art piston and firing chamber generation and second embodiment of the invention and the flue dust that the firing chamber produces;

Fig. 9 is the sectional view of the piston of the third embodiment of the present invention;

Figure 10 is the diagram by the comparison of the piston of the NOx of prior art piston and firing chamber generation and third embodiment of the invention and the NOx that the firing chamber produces;

Figure 11 is the diagram by the comparison of the piston of the flue dust of prior art piston and firing chamber generation and third embodiment of the invention and the flue dust that the firing chamber produces;

Figure 12 is the piston of the fourth embodiment of the present invention and the sectional view of firing chamber;

Figure 13 is for the pressure B0 of the crankangle of prior art motor posterior infromation (a kind of simulation of same motor to embody simulation validity), with the diagram of simulation B44a that has a motor of the piston of the fourth embodiment of the present invention and firing chamber;

Figure 14 is the diagram by the comparison of the piston of the NOx of prior art B0 piston and firing chamber generation and fourth embodiment of the invention B44a and the NOx that the firing chamber produces;

Figure 15 is the diagram by the comparison of the piston of the flue dust of prior art B0 piston and firing chamber generation and fourth embodiment of the invention B44a and the flue dust that the firing chamber produces;

Figure 16 is the piston of the fifth embodiment of the present invention and the sectional view of firing chamber;

Figure 17 is that (a kind of simulation B0 of same motor is to embody simulation validity for the B0 of the Nox of the crankangle generation of prior art motor posterior infromation, basically overlapping posterior infromation), with the diagram of B27 of simulation that has a motor of the piston of the fifth embodiment of the present invention and firing chamber; And

Figure 18 is the diagram by the comparison of the piston of the flue dust of prior art B0 piston and firing chamber generation and fifth embodiment of the invention B27 and the flue dust that the firing chamber produces.

The detailed description of accompanying drawing

First embodiment

Piston of the present invention illustrates with label " 10 " in Fig. 1 usually.Top 12 parts of piston 10 form the top sides distance of piston 10.Firing chamber 14 of the present invention is formed in the top 12.Should be noted that: firing chamber 14 is with respect to longitudinal axis 16 symmetries, and the central axes of longitudinal axis 16 and piston 10.The various radiuses (R) that to describe below, diameter (D) and height (H) are shown clearly in the describing of Fig. 1.

Piston 10 of the present invention mainly is designed for large diesel engine, but also is applicable to than LD-diesel.Piston 10 can use the head of 2 valves or many valves.It is desirable to, fuel is spraying near the piston center, and spray pattern is radially symmetrical.In a preferred embodiment, sparger ejects injected fuel spray stream, and it has the thin spray flow that discharge on 6 strands of relative axis 16 equal angles ground.

The 12 interior firing chambers 14, top that are formed on piston 10 are made up of the curved surface that comprises sphere and ring surface.Sphere is represented by radius R S, and ring surface is represented by radius R.Firing chamber 14 does not have flat surface.Between the various curved surfaces that form firing chamber 14, a transition level and smooth, tangent line is arranged, will describe in more detail below.

Usually, firing chamber 14 is made up of two sphere RS1 and RS2, and sphere RS1 forms a center goalpost 17.Two sphere RS1 are connected by the ring surface R1 of 14 bottoms in the firing chamber with RS2.Sphere RS2 carries out the transition to piston head 12 by two ring surface R2, R3, and ring surface has relatively little bending, and is connected with top 12 formation, one cavity.Diameter dimension illustrates with D, and height dimension illustrates with H.

The parameter of existing many controls firing chamber 14 geometrical shapies, thus, the discharging of may command diesel combustion characteristic and NOx and flue dust.The a part of sphere that is formed by radius R S1 is positioned at the central space (core) of firing chamber 14.The centre of sphere 18 of sphere RS1 is positioned on the central axis 16 of piston 10.Distance between the intersection point of the bottom surface 20 of the centre of sphere 18 of sphere RS1 and axis 16 and firing chamber 14 is equal to or greater than 0, and should be less than 0.25D2.Describe as Fig. 1, the centre of sphere 18 is on the intersection point 22 of the bottom surface 20 of the axis 16 of firing chamber 14 and firing chamber 14.In other words, the centre of sphere 18 overlaps with intersection point 22.This preferable deployment that is the centre of sphere 18 on the intersection point 22 of the axis 16 of firing chamber 14 and the bottom surface 20 of firing chamber, but the centre of sphere 1 with and intersection point 22 between a vertical height distance also can be arranged.

Second sphere with radius R S2 is positioned at the outside of first (core) sphere RS1, and part forms an external edge of firing chamber 14 apart from (outer margin).External edge has a centre of sphere 23 on central axis 16 apart from sphere RS2.Core sphere RS1 and external edge are equal to or greater than 0.0 and less than ± 2 (R1) apart from the distance between two corresponding centre ofs sphere 22,23 of sphere RS2.Preferably, described distance is zero, and two centre ofs sphere 22,23 are concentric, and preferably are positioned at the central axis 16 of firing chamber 14 and the intersection point of bottom surface 20.Should be noted that: distance value is positive when the centre of sphere 23 promotes with respect to the centre of sphere 22, and Fig. 1 illustrates a positive distance H 1.In addition, the ratio of RS2/RS1 is equal to or greater than 1.0, and less than 3.0.RS2/RS1 preferably is about 2.0, and especially 2.073.

Following ratio limits certain several parameter of firing chamber 14.

The ratio of a.RS1/D2 is greater than 0.10, and less than 0.45, and preferably be 0.253.

The ratio of b.D2/D1 is greater than 0.45, and less than 0.85, and preferably be 0.619.

The ratio of c.D3/D2 is greater than 0.75, and less than 0.95, and preferably be 0.849.

The ratio of d.H/D2 is greater than 0.15, and less than 0.45, and preferably be 0.337.

The ratio of e.R1/D2 is greater than 0.11, and less than 0.45, and preferably be 0.136.

The ratio of f.R2/D2 is greater than 0.0, and less than 0.35, and preferably be 0.11.

The ratio of g.R3/D2 is greater than 0.0, and less than 0.2, and preferably be 0.14.

Foregoing firing chamber 14 by sphere and ring surface in conjunction with forming.Should be noted that the transition between RS1 and the R1 is level and smooth and tangent line, the transition between R1 and the RS2 is level and smooth and tangent line, and transition is level and smooth and tangent line between RS2 and the R2, and the transition between R2 and the R3 is level and smooth and tangent line.Therefore, there is not flat surface to form firing chamber 14.Foregoing curve and seamlessly transitting impels the smooth flow in the firing chamber 14, and is used for reducing the thermal force in firing chamber 14.In addition, firing chamber 14 is with respect to axis 16 symmetries.Therefore, compare, far beyond easily rotating (turn) firing chamber 14 with the asymmetric firing chamber in being formed on a piston.

Should further be recognized that radius R 2, R3 forming a bowl-in-piston chamber 14 with 12 intersections, top, obviously are different from the firing chamber of the opening of some descriptions of the Prior Art.

In the improvement of combustion performance shown in Fig. 2-4 and the minimizing of pollutant emission.With reference to Fig. 2, power output is the zone under each curve.The experiment of one first reality of one known firing chamber illustrates with curve 24.Near the peak value of curve 24, the analog track of known firing chamber causes curve 24 closely overlapping with curve 24.Closely confirmed the correctness of simulation with the overlapping track 26 of curve 24.Then, this identical simulation is used for the performance of simulated combustion chamber 14.The simulation of firing chamber 14 illustrates with curve 28.Should be noted that: regional bigger in the zone below the curve 28 than below the curve 24 illustrates that from the firing chamber 14 output is more bigger than the power output of known firing chamber.

Fig. 3 illustrates the analog result (shown in line 28) of the NOx (shown in line 26) and the NOx that firing chamber of the present invention 14 produces of known combustion chamber generation.Should be noted that: the NOx that the NOx that firing chamber 14 of the present invention is produced produces less than the known combustion chamber shown in the line 6 significantly.

The comparison of the flue dust (shown in line 28) of the simulation that the flue dust (shown in line 26) that Fig. 4 illustrates the simulation that a known firing chamber produces and firing chamber 14 of the present invention produce.Should be noted that: the flue dust that the flue dust that firing chamber 14 of the present invention is produced produces less than the known combustion chamber significantly.Should notice significantly: with reference to Fig. 2-4, firing chamber 14 is compared with known firing chamber, and it causes power output to increase and reduced simultaneously NOx and flue dust that the firing chamber produces.

Second embodiment

Piston of the present invention illustrates with label " 210 " in Fig. 5 usually.Top 212 parts of piston 210 form the top sides distance of piston 210.Firing chamber 214 of the present invention is formed in the top 212.Should be noted that: firing chamber 214 is with respect to longitudinal axis 216 symmetries, and the central axes of longitudinal axis 216 and piston 210.The various radiuses (R) that to describe below, diameter (D) and height (H) are shown clearly in the describing of Fig. 5.

Piston 210 of the present invention mainly is designed for large diesel engine, but also is applicable to than LD-diesel.Piston 210 can use the head of 2 valves or many valves.It is desirable to fuel and spraying, and spray pattern is radially symmetrical near the piston center.In a preferred embodiment, sparger ejects injected fuel spray stream, and it has the thin spray flow that discharge on 6 strands of relative axis 216 equal angles ground.

The 212 interior firing chambers 214, top that are formed on piston 210 are made up of the curved surface that comprises sphere and ring surface.Firing chamber 214 does not have flat surface.Between the various curved surfaces that form firing chamber 214, a transition level and smooth, tangent line is arranged, will describe in more detail below.

The parameter of existing many controls firing chamber 214 geometrical shapies thus, can be controlled the discharging of diesel combustion characteristic and NOx and flue dust.The a part of sphere that is formed by radius R 1 is positioned at the central space of firing chamber 214, and forms a center goalpost 217.The centre of sphere 218 of sphere R1 is positioned on the central axis 216 of piston 210.Distance between the intersection point of the bottom surface 220 of the centre of sphere 218 of sphere R1 and axis 216 and firing chamber 214 is equal to or greater than 0, and should be less than 0.2D.Describe as Fig. 5, the centre of sphere 218 is on the intersection point 222 of the bottom surface 220 of the axis 216 of firing chamber 214 and firing chamber 214.In other words, the centre of sphere 218 overlaps with intersection point 222.This preferable deployment that is the centre of sphere 218 on the intersection point 222 of the axis 216 of firing chamber 214 and the bottom surface 220 of firing chamber, but between the centre of sphere 218 and intersection point 222, a vertical height distance can be arranged also.

Following ratio limits certain several parameter of firing chamber 214.

The ratio of a.D1/D is greater than 0.49, and less than 0.81, and preferably be 0.6065.

The ratio of b.D2/D1 is greater than 0.81, and less than 0.99, and preferably be 0.908.

The ratio of c.H1/D1 is greater than 0.17, and less than 0.47, and preferably be 0.344.

The ratio of d.H2/H1 is greater than 0.05, and less than 0.45, and preferably be 0.253.

The ratio of e.R1/D1 is greater than 0.13, and less than 0.43, and preferably be 0.257.

The ratio of f.R2/D1 is greater than 0.09, and less than 0.25, and preferably be 0.133.

The ratio of g.R3/D1 is greater than 0.17, and less than 0.55, and preferably be 0.36.

The ratio of h.R4/D1 is greater than 0.08, and less than 0.33, and preferably be 0.142.

The ratio of i.R5/D1 is greater than 0.01, and less than 0.02, and preferably be 0.14.

Foregoing firing chamber 214 by sphere and ring surface in conjunction with forming.Sphere R1 is formed by radius R 1.Ring surface is formed by radius R 2-R5.Should be noted that: the transition between sphere R1 and the ring surface R2 is level and smooth and tangent line, transition between ring surface R2 and the ring surface R3 is level and smooth and tangent line, transition is level and smooth and tangent line between ring surface R3 and the ring surface R4, and the transition between ring surface R4 and the ring surface R5 is level and smooth and tangent line.Therefore, there is not flat surface to form firing chamber 214.Foregoing curve and seamlessly transitting impels the smooth flow in the firing chamber 214, and is used for reducing the thermal force in firing chamber 214.In addition, firing chamber 214 is with respect to axis 216 symmetries.Therefore, compare with the asymmetric firing chamber in being formed on a piston, far beyond easily rotating firing chamber 214.

The face R3-R5 of should further be recognized that forms a bowl-in-piston chamber 214, obviously is different from the firing chamber of the opening of description of the Prior Art.

The improvement of combustion performance and the minimizing of pollutant emission have been shown in Fig. 6-8.With reference to Fig. 6, power output is the zone under each curve.The experiment of one first reality of one known firing chamber illustrates with curve 224.Near the peak value of curve 224, it is closely overlapping with curve 224 that the analog track of known firing chamber produces curve 224.Closely confirmed the correctness of simulation with the overlapping track 226 of curve 224.Then, this identical simulation is used for the performance of simulated combustion chamber 214.The simulation of firing chamber 214 illustrates with curve 228.Should be noted that: regional bigger in the zone below the curve 228 than below the curve 224 illustrates that from the firing chamber 214 output is more bigger than the power output of known firing chamber.

Fig. 7 illustrates the analog result (shown in line 228) of the NOx (shown in line 226) and the NOx that firing chamber of the present invention 214 produces of known combustion chamber generation.Should be noted that: the NOx that the NOx that firing chamber 214 of the present invention is produced produces less than the known combustion chamber shown in the line 226 significantly.

The comparison of the flue dust (shown in line 228) of the simulation that the flue dust (shown in line 226) that Fig. 8 illustrates the simulation that a known firing chamber produces and firing chamber 214 of the present invention produce.Should be noted that: the flue dust that the flue dust that firing chamber 214 of the present invention is produced produces less than the known combustion chamber significantly.Should notice significantly: with reference to Fig. 6-8, firing chamber 214 is compared with known firing chamber, and it causes power output to increase and reduce simultaneously NOx and the flue dust that the firing chamber produces.

The 3rd embodiment

Usually with label " 310 ", " 314 " illustrate in Fig. 9 for piston of the present invention and firing chamber of the present invention.Usually, piston 310 has the depression up of the symmetry of a centralized positioning, and it is used for being formed on a major component of the combustor inner cylinder ware of diesel engine, and motor has a fuel injector that is used to form a fuel jet flow.Piston 310 can use the head of 2 valves or many valves.It is desirable to fuel and spraying, and spray pattern is radially symmetrical near piston 310 centers.In a preferred embodiment, sparger ejects injected fuel spray stream, and it has the thin spray flow that discharge on 6 strands of relative axis 316 equal angles ground.The piston 310 that has a firing chamber 314 has effectively reduced the diesel engine pollutant emission such as NOx and flue dust.Piston 310 preferably is applicable to heavy and middle diesel engine.

Top 312 parts of piston 310 form the top sides distance of piston 310.Firing chamber 314 of the present invention is formed in the top 312.Should be noted that: firing chamber 314 is with respect to longitudinal axis 316 symmetries of chamber, and the central axes of longitudinal axis 316 and piston 310.The various radiuses (R) that to describe below, diameter (D) and height (H) are shown clearly in the describing of Fig. 9.

The 312 interior firing chambers 314, top that are formed on piston 310 are made up of the curved surface that comprises sphere and ring surface.Sphere represented by radius R S, and may be that the curved surface of ring surface is indicated by radius R.Firing chamber 314 does not have flat surface.Have one smoothly between the various curved surfaces of firing chamber 314 forming, be generally the transition of tangent line, will describe in more detail below.

Usually, firing chamber 314 is made up of two sphere RS1 and RS2, and RS1 forms a protruding sphere, and RS2 forms a concave spherical surface.Sphere RS1 is formed on the center of the firing chamber 314 that forms a center short column 317, and sphere RS2 radially forms in sphere RS1 outside simultaneously.Two sphere RS1 and RS2 are connected by the circlet shape face that 314 bottoms in the firing chamber have a radius R 2.Sidewall of combustion chamber is formed by a bent ring surface with R1 radius.Sidewall curved surface R1 is connected to sphere RS2 by a curved surface with radius R 3.Sidewall curved surface R1 by means of a little curved surface (such as, R4) transit to the intersection point that intersects with top 312.

The parameter of existing many controls firing chamber 314 geometrical shapies thus, can be controlled the discharging of diesel combustion characteristic and NOx and flue dust.The protruding sphere RS1 that is formed by radius R S1 is positioned at the center bottom space (core) of firing chamber 14.On the firing chamber longitudinal axis 316 that the centre of sphere 318 of sphere RS1 is positioned at preferably with the longitudinal axis of piston 310 overlaps.Distance between the intersection point of the bottom surface 320 of the centre of sphere 318 of sphere RS1 and axis 316 and firing chamber 314 is equal to or greater than 0 (as shown in Figure 9, the distance of upwards measuring from the centre of sphere be on the occasion of), and should be less than 0.3D1 (D1 is the diameter of piston 310).Described distance preferably is zero, and wherein, the centre of sphere 318 overlaps with the intersection point 322 of bottom surface 320 and axis 16.

Concave spherical surface with diameter RS2 makes its centre of sphere 324 on axis 316, and as shown in Figure 9, above piston 310.Distance between the intersection point 322 of the centre of sphere 324 of sphere RS2 and bottom surface 320 and axis 316 is equal to or greater than 1.0D1, and less than 8.0D1, and preferably is 2.5D1 (distance of upwards measuring from the intersection point of bottom surface 320 and axis 316 be on the occasion of) as shown in Figure 9.

Following ratio defines certain several parameter of firing chamber 314, D2 is the maximum diameter of firing chamber 314, D3 be firing chamber 314 with the diameter at the intersection point place on top 312, H1 is the maximum height of firing chamber 314, and H2 for from the summit of protruding sphere RS1 to the height that pushes up 312.

The ratio of a.RS1/D2 is greater than 0.11, and less than 0.44, and preferably be 0.245.

The ratio of b.RS2/D2 is greater than 1.5, and less than 30.0, and preferably be 3.432.

The ratio of c.D2/D1 is greater than 0.42, and less than 0.88, and preferably be 0.635.

The ratio of d.D3/D2 is greater than 0.7, and less than 0.995, and preferably be 0.832.

The ratio of e.H1/D2 is greater than 0.13, and less than 0.49, and preferably be 0.318.

The ratio of f.H2/D2 is greater than 0.005, and less than 0.49, and preferably be 0.073.

The ratio of g.R1/D2 is greater than 0.11, and less than 0.65, and preferably be 0.412.

The ratio of h.R2/D2 is greater than 0.01, and less than 0.33, and preferably be 0.068.

The ratio of i.R3/D2 is greater than 0.01, and less than 0.33, and preferably be 0.068.

The curve of foregoing firing chamber 314 and seamlessly transitting impels the smooth flow in the firing chamber 314, and is used for reducing the thermal force in firing chamber 314.In addition, firing chamber 314 is with respect to axis 316 symmetries.Therefore, compare with the asymmetric firing chamber in being formed on a piston, far beyond easily rotating firing chamber 314.

In the improvement of combustion performance shown in Figure 10 and Figure 11 and the minimizing of pollutant emission.Figure 10 illustrates the analog result (shown in line 330) of the NOx (shown in line 328) and the NOx that firing chamber of the present invention 314 produces of known combustion chamber generation.Should be noted that: the NOx that the NOx (line 330) that firing chamber 314 of the present invention is produced produces less than the known combustion chamber shown in the line 328 significantly.

The comparison of the flue dust (shown in line 330) of the simulation that the flue dust (shown in line 328) that Figure 11 illustrates the simulation that a known firing chamber produces and firing chamber 314 of the present invention produce.Should be noted that: the flue dust (line 328) that the flue dust (line 330) that firing chamber 314 of the present invention is produced produces less than the known combustion chamber significantly.

The 4th embodiment

Usually respectively with label " 410 ", " 414 " illustrate in Figure 12 for piston of the present invention and firing chamber.Usually, piston 410 has the depression up of the symmetry of a centralized positioning, and it is used for being formed in the cylinder of diesel engine the part of a complete firing chamber.Firing chamber 414 is formed in the top 412 of piston 410.Motor has a fuel injector that is used to form a fuel jet flow of relative combustion chamber 414.Piston 410 can use the head of 2 valves or many valves.It is desirable to fuel and spraying, and spray pattern is radially symmetrical with respect to axis 416 near piston 410 centers.Piston 410 has effectively reduced the diesel engine pollutant emission (shown in the curve of Figure 14 and 15) such as NOx and flue dust.Piston 410 preferably is applicable to heavy and middle diesel engine.

Top 412 parts of piston 410 form the top sides distance of piston 410.Firing chamber 414 of the present invention is formed in the top 412.Should be noted that: firing chamber 414 is with respect to firing chamber longitudinal axis 416 symmetries, and longitudinal axis 416 preferably overlaps with the central axis of piston 410.The various radiuses (R) that to describe below, diameter (D) and height (H) are shown clearly in the describing of Figure 12.RS represents spherical radius, and ring surface is indicated by radius R.

The firing chamber 414 of piston 410 is made up of the curved surface that comprises sphere and ring surface.Firing chamber 414 does not have flat surface.Have one smoothly between the various curved surfaces of firing chamber 414 forming, be generally the transition of tangent line, will describe in more detail below.

Normally, firing chamber 414 is made up of four of three parameters, and as shown in figure 12, they comprise:

(1) diameter group (group);

(2) spherical set;

(3) highly organize; And

(4) circular groups.

The diameter group comprises three diameter parameters, and wherein, D1 is the diameter of piston 410, and D2 is the diameter of firing chamber 414, and D3 is firing chamber 414 and the diameter that pushes up the cavity of 412 firing chambers 414 of intersecting.Spherical set comprises three spheres that have radius R S1, RS2 and RS3 respectively.Highly group comprises three height parameters, and wherein, H1 is the degree of depth of firing chamber 414, and H2 is the distance between the summit of piston head 412 and protruding sphere RS1, and H3 is the thickness of the cavity of firing chamber 414.Circular groups comprises three ring surfaces that comprise radius R 1, R2 and R3 respectively.

Protruding sphere RS1 is positioned at the center of 414 bottoms, firing chamber that form a center short column 417.Two sphere RS2 and RS3 form the sidewall of firing chamber 414 respectively.Two sphere RS1 are connected by ring surface R1 with RS2.Ring surface R1 forms the bottom of firing chamber 414.Two spherical RS2 are connected by a circlet shape face R2 with RS3, therefore, form a level and smooth transition between two sphere RS2 and RS3.Sphere RS3 carries out the transition to top 412 by means of a circlet shape face R3.The center of three sphere RS1, RS2 and RS3 all is positioned on the firing chamber longitudinal axis 416, forms the center line of firing chamber 414.

Below the correlation of all parameters controlled the geometrical shape of firing chamber 14 and the emission result that uses the diesel engine of piston 410 and firing chamber 414.

The ratio of a.D2/D1 is greater than 0.43, and less than 0.83, and preferably be 0.631.

The ratio of b.D3/D2 is greater than 0.68, and less than 0.998, and preferably be 0.883.

The ratio of c.RS1/D1 is greater than 0.08, and less than 0.38, and preferably be 0.181.

The ratio of d.RS2/D2 is greater than 0.16, and less than 0.56, and preferably be 0.364.

The ratio of e.RS3/D1 is greater than 0.18, and less than 0.48, and preferably be 0.282.

The ratio of f.H1/D2 is greater than 0.12, and less than 0.52, and preferably be 0.321.

The ratio of g.H2/D1 is greater than 0.006, and less than 0.256, and preferably be 0.056.

The ratio of h.H3/D1 is greater than 0.01, and less than 0.45, and preferably be 0.05.

The ratio of i.R1/D1 is greater than 0.02, and less than 0.28, and preferably be 0.081.

The ratio of j.R2/D1 is equal to or greater than 0, and less than 0.31, and preferably be 0.017.

The ratio of k.R3/D1 is equal to or greater than 0, and less than 0.31, and preferably be 0.009.

The curve of foregoing firing chamber 414 and seamlessly transitting impels the smooth flow in the firing chamber 414, and is used for reducing the thermal force in firing chamber 414.In addition, firing chamber 414 is with respect to axis 416 symmetries.Therefore, compare with the asymmetric firing chamber in being formed on a piston, far beyond easily rotating firing chamber 414.

Figure 13 illustrates the comparison by the combustion performance of inner cylinder pressure indication, wherein, and the power output of Regional Representative's one diesel engine of pressure diagram below.Should be realized that: at Figure 13, in 14 and 15, the experimental result basically identical of the analog result of prior art motor and prior art motor has illustrated the accuracy of simulation.Get back among Figure 13, pressure diagram B44a of the present invention is more bigger than the pressure diagram B0 of prior art motor, and the performance of this explanation motor of the present invention is slightly better than the performance of prior art motor, and power output of the present invention is more bigger than prior art motor.

In the improvement of combustion performance shown in Figure 14 and Figure 15 and the minimizing of pollutant emission.Figure 14 shows the analog result (shown in line B44a) of the NOx (shown in line B0) and the NOx that firing chamber of the present invention 414 produces of known combustion chamber generation.Should be noted that: the NOx that the NOx that firing chamber 414 of the present invention is produced produces less than the known combustion chamber shown in the line B0 significantly.

The comparison of the flue dust (shown in line B44a) of the simulation that the flue dust (shown in line B0) that Figure 15 illustrates the simulation that a known firing chamber produces and firing chamber 414 of the present invention produce.Should be noted that: the flue dust (line B0) that the flue dust (line B44a) that firing chamber 414 of the present invention is produced produces less than the known combustion chamber significantly.

The 5th embodiment

Usually respectively with label " 510 ", " 512 " illustrate in Figure 16 for piston of the present invention and firing chamber.Usually, piston 510 has the depression up of the symmetry of a centralized positioning, and it is used for being formed on the part of the firing chamber in the cylinder of diesel engine.Firing chamber 512 is formed in the top 512 of piston 510.Motor has the fuel injector that is used to form relative combustion chamber 512 1 fuel jet flows.Piston 510 can use the head of 2 valves or many valves.Piston 510 has effectively reduced the diesel engine pollutant emission such as NOx and flue dust, shown in the diagram of Figure 17 and 18.Piston 510 preferably is applicable to heavy and middle diesel engine.

Piston 510 have a symmetry towards upper shed firing chamber 512, it is used for being formed in the cylinder of diesel engine a major component of a complete firing chamber, motor has a fuel injector that is used to form a fuel jet flow, does not damage fuel economy and power output so that reduce such as the diesel engine pollutant emission of NOx and flue dust.

Firing chamber 512 is positioned at the piston head 514 of diesel engine, and mainly comprises one group of sphere, as shown in figure 16.Make concentricity 516 to be positioned at the major component that two sphere RS1 on the firing chamber axis 518 and RS2 form firing chamber 512.Inner ball surface RS1 is positioned at the centre bottom of firing chamber 512, forming a short column 520, and has the radius of a RS1.Outer spherical surface RS2 forms the bottom of the sidewall of firing chamber 512, and has the radius of a RS2.One the 3rd sphere RS3 with RS3 radius forms the exterior base back gauge of firing chamber 512.One the 4th sphere RS4 with RS4 radius forms the higher part of the sidewall of firing chamber 512.

Four circlet shape face R1-R4 as transitional surface between the contiguous sphere with being connected of top 514.Inner ball surface RS1 is connected by the ring surface with R1 radius with outer bottom sphere RS3.Lower wall sphere RS2 is connected by the ring surface with R2 radius with outer bottom sphere RS3.Lower wall sphere RS2 is connected by the ring surface with radius R 3 with upper side wall sphere RS4.Upper side squash face RS4 transits to or inserts piston head 514 by the circlet shape face R4 with radius R 4.

The centre of sphere of sphere RS1 and RS2 overlaps each other, and in other words, they have a common center 516, and this common center 516 is positioned on the central axis 518 of firing chamber 512.Distance between the common center 516 of sphere RS1 and RS2 and firing chamber axis 518 and firing chamber bottom surface 522 intersection points is equal to or greater than 0, and less than 0.28D1, D1 is the diameter of piston, and preferably is 0.073D1.The centre of sphere of sphere RS3 is positioned on the central axis 518 of firing chamber, and the distance between the intersection point of the bottom surface 522 of the centre of sphere of sphere RS3 and firing chamber axis 518 and firing chamber 512 is greater than 0.75D1, and less than 3.0D1, and preferably be 2.178D1.The centre of sphere of sphere RS4 is positioned on the central axis 518 of firing chamber 512, and the distance between the intersection point on the top 514 of the centre of sphere of sphere RS4 and firing chamber axis 518 and piston 510 equals H3.The ratio of H3/D1 is greater than 0.02, and less than 0.42, and preferably be 0.051.

The central axis 518 of firing chamber 512 can overlap with the central axis 524 of piston 510, or have a side-play amount, in other words, the distance H 4 between the central axis 518 of firing chamber 512 and the central axis 524 of piston 510 is equal to or greater than 0, and less than 0.1D1, and preferably be 0.Preferably, axis 518 and 524 overlaps.

The relation of other of all parameters has also been controlled geometrical shape and the combustion performance of diesel engine and the effulent in the diesel engine of firing chamber, as listed below:

1.D2/D1 ratio greater than 0.43, and less than 0.83, and preferably be 0.637, D2 is the maximum diameter of firing chamber.

2.D3/D1 ratio greater than 0.33, and less than 0.83, and preferably be 0.548, D3 is the minimum diameter of firing chamber.

3.RS1/D1 ratio greater than 0.05, and less than 0.35, and preferably be 0.18.

4.RS2/D1 ratio greater than 0.23, and less than 0.53, and preferably be 0.334.

5.RS3/D1 ratio greater than 1.18, and less than 4.18, and preferably be 2.18.

6.RS4/D1 ratio greater than 0.18, and less than 0.38, and preferably be 0.28.

7.H1/D1 ratio greater than 0.1, and less than 0.4, and preferably be 0.2, H1 is the degree of depth of firing chamber.

8.H2/D1 ratio greater than 0.04, and less than 0.24, and preferably be 0.144, H2 is the height of piston.

9. the radius of ring surface R1 equals the radius of ring surface R2.The ratio of R1/D1 and R2/D1 is all greater than 0.03, and less than 0.25, and preferably be 0.051.

10. the radius of ring surface R3 and R4 is very little.Therefore, the ratio of R3/D1 and R4/D1 is all greater than 0, and less than 0.1.

The curve of foregoing firing chamber 512 and seamlessly transitting impels the smooth flow in the firing chamber 512, and is used for reducing the thermal force in firing chamber 512.In addition, firing chamber 512 is preferably with respect to piston axis 524 symmetries, but can be offset distance H 4 as shown in figure 16.Therefore, compare, far beyond easily rotating (formation) firing chamber 512 with the asymmetric firing chamber in being formed on a piston.

Should be realized that: in Figure 17 and 18, the experimental result basically identical of the analog result of prior art motor and prior art motor (experience track and analog track, B0 and B0 overlap substantially) has illustrated the accuracy of simulating.In the improvement of combustion performance shown in Figure 17 and Figure 18 and the minimizing of pollutant emission.Figure 17 illustrates the analog result (shown in line B27) of the NOx (shown in line B0) and the NOx that firing chamber of the present invention 512 produces of known combustion chamber generation.Should be noted that: the NOx that the NOx that firing chamber 512 of the present invention is produced produces less than the known combustion chamber shown in the line B0 significantly.

The comparison of the flue dust (shown in line B27) of the simulation that the flue dust (shown in line B0) that Figure 18 illustrates the simulation that a known firing chamber produces and firing chamber 512 of the present invention produce.Should be noted that: the flue dust (line B0) that the flue dust that firing chamber 512 is produced (line B27) produces less than the known combustion chamber significantly.

Obviously, those skilled person in the present technique field will appreciate that, except embodiment described here, also can point out other various embodiments in the application's scope and width.Therefore, the applicant's intention is only limited by appended claims.

Claims

1. the piston with firing chamber that is used in the diesel engine comprises:

One is formed on the firing chamber of a piston head, this piston has a central axis, this firing chamber has a side wall surface and forms a core of a cylinder, this core is formed by the part of a spheroid at least in part, this spheroid has a radius, the centre of sphere drops on the piston middle spindle line, and this side wall surface is formed by a sphere that is connected to bottom surface; The firing chamber also has some level and smooth tangent line transition between the smooth surface of all adjacency, and smooth surface comprises spherical core and side wall surface, and the firing chamber is with respect to firing chamber longitudinal axis symmetry.

2. piston as claimed in claim 1 is characterized in that, the centre of sphere of core sphere is positioned at the bottom surface of firing chamber or is positioned at the below of the bottom surface of firing chamber.

3. piston as claimed in claim 2 is characterized in that, the centre of sphere of core sphere overlaps with the intersection point of bottom surface and piston middle spindle line.

4. as each described piston in the claim 1,2 and 3, it is characterized in that described firing chamber does not have flat surface.

5. piston as claimed in claim 1 is characterized in that, curved surface formation one and piston head connect the concave panel on boundary.

6. piston as claimed in claim 1 is characterized in that, the bottom surface of firing chamber is formed by a sphere that combines with cylinder.

7. piston as claimed in claim 1 is characterized in that, the bottom surface of firing chamber is formed by a ring surface that combines with cylinder.

8. one kind forms a method that is used for the firing chamber in the diesel engine, and it comprises:

Form a firing chamber at a piston head, this piston has a central axis;

Formation one has the cylinder of a firing chamber core; Core is formed by the part of a spheroid at least in part, and this spheroid has a radius;

The centre of sphere is arranged on the central axis of piston;

Form a side wall surface of firing chamber with the sphere that is connected to bottom surface, and some level and smooth tangent line transition also are set between the smooth surface of all adjacency, smooth surface comprises spherical core and side wall surface; And

The firing chamber is provided with symmetrically with respect to the firing chamber longitudinal axis.

9. method as claimed in claim 8 is characterized in that, comprises the centre of sphere that the core sphere is set, and this centre of sphere is in the bottom plane of firing chamber or be positioned at below the bottom plane, firing chamber.

10. method as claimed in claim 9 is characterized in that, comprises the centre of sphere that the core sphere is set, and this centre of sphere overlaps with the intersection point of bottom plane and piston middle spindle line.

11. as claim 8, any one the described method in 9,10 is characterized in that, comprises that the firing chamber of formation does not have flat surface.

12. method as claimed in claim 8 is characterized in that, comprises the concave panel that meets the boundary with curved surface formation one and piston head.

13. method as claimed in claim 8 is characterized in that, comprises a bottom surface that is formed the firing chamber by a sphere that combines with cylinder.

14. method as claimed in claim 8 is characterized in that, comprises a bottom surface that is formed the firing chamber by a ring surface that combines with cylinder.