Engine hydraulic variable inlet valve different lift mechanism and engine

Abstract

The invention relates to the technical field of engine variable valves, in particular to an engine hydraulic variable inlet valve different lift mechanism and an engine, a tappet compresses medium oil under the driving of a cam shaft to build pressure, and two pistons walk out different valve lift curves due to different diameters under the pushing of oil pressure; or different valve lift curves are formed due to the difference of the two valve springs; or different valve lift curves are formed under the combined action of different diameters of the pistons and different valve springs. Compared with the prior art, cost is low, engine modification is small, and modification and upgrading of an existing machine type are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of engine variable valves, and in particular to an engine hydraulic variable intake valve differential lift mechanism and an engine. Background Art

[0002] For the intake in the engine cylinder, the coexistence of tumble and swirl is more conducive to the organization of the combustion process. However, due to the symmetrical arrangement of the dual intake duct structure of the traditional four-valve engine, and the use of the valve bridge to drive the two intake valves at the same time, the two intake valves are opened to the same extent at the same time, so that the intake speed and intake volume of the two intake valves are the same at the same time. The rotating airflows in the cross-sectional direction of the cylinder cancel each other out, and the overall movement of the air in the cylinder is manifested as a single longitudinal tumble pattern with almost no swirl. This is an important factor causing poor mixture formation and worsening combustion. If tangential air ducts or rotating air ducts are used to obtain swirls to improve combustion conditions and emission performance, the cylinder head structure will be complicated and the airflow resistance will increase. When the opening degrees of the two intake valves are different, larger swirls can be generated, which promote combustion mixing to a certain extent and improve combustion efficiency.

[0003] Hydraulic variable valve lift plays a positive role in promoting combustion and improving emission performance, but most of them are to reduce the lift of two intake valves at the same time to obtain a strong vortex, which is equivalent to partially closing the two intake valves. When the two intake valves are fully open at high speed, there is no vortex. For details, please refer to patent CN214944476U; In order to realize the existence of vortexes in the two intake valves at high speed, patent CN115182800A discloses a hydraulic valve mechanism for realizing different lifts of valves with the same name. In order to realize different lifts, the patent adopts a method of a set of independent control mechanisms for each valve, but the two sets of independent control mechanisms inevitably have the problem of limited installation space and high cost; Patent CN208220853U discloses a diesel engine valve mechanism that can form an intake vortex. The mechanism arranges two intake valves diagonally so that the two intake air flows can produce a staggered offset effect. This method causes relatively large changes to the engine and is not conducive to the transformation and upgrading of existing models. Summary of the invention

[0004] In order to solve the technical problems existing in the prior art, the purpose of the present invention is to provide an engine hydraulic variable intake valve different lift mechanism and method to solve the problem of the existing four-valve engine's demand for the hydraulic variable valve intake valve swirl intensity.

[0005] In order to achieve the above object, the present invention solves it through the following technical solutions: In the first aspect, the present invention provides an engine hydraulic variable intake valve differential lift mechanism, comprising: a camshaft, a tappet, a first piston, a second piston, a first intake valve, a second intake valve, a first valve spring, and a second valve spring. The tappet compresses medium oil under the drive of the camshaft to build up pressure and drive the first piston and the second piston. The first piston drives the first intake valve, and the second piston drives the second intake valve. The first intake valve is equipped with a first valve spring; the second intake valve is equipped with a second valve spring; the diameters of the first piston and the second piston are different.

[0006] As a further technical solution, the cross-sectional area SA of the first piston and the cross-sectional area SB of the second piston are calculated by the following formula: =

[0007]

[0008] Among them, F A0 is the spring preload of the first valve spring; F B0 is the spring preload of the second valve spring; K A is the stiffness of the first valve spring; K B is the stiffness of the second valve spring; L Amax L is the maximum lift of the intake valve at full opening; Bmax =L Amax -δ; δ is the maximum lift difference between the first intake valve and the second intake valve; according to the cross-sectional area S of the first piston A , the cross-sectional area S of the second piston B , and obtain the diameters of the first piston and the second piston.

[0009] In a second aspect, the present invention provides an engine comprising the engine hydraulic variable valve different lift mechanism as described above.

[0010] In a third aspect, the present invention provides an engine hydraulic variable intake valve differential lift mechanism, comprising: a camshaft, a tappet, a first piston, a second piston, a first intake valve, a second intake valve, a first valve spring, and a second valve spring. The tappet compresses medium oil under the drive of the camshaft to build up pressure and drive the first piston and the second piston. The first piston drives the first intake valve, and the second piston drives the second intake valve. The first intake valve is equipped with a first valve spring; the second intake valve is equipped with a second valve spring; the first valve spring and the second valve spring are different.

[0011] As a further technical solution, the first valve spring and the second valve spring are different including that the first valve spring and the second valve spring have exactly the same stiffness but different preload forces; or the first valve spring and the second valve spring have different stiffness but the same preload forces, or the first valve spring and the second valve spring have different stiffness and different preload forces.

[0012] In a fourth aspect, the present invention provides an engine comprising the engine hydraulic variable valve different lift mechanism as described above.

[0013] In a fifth aspect, the present invention provides an engine hydraulic variable intake valve differential lift mechanism, comprising: a camshaft, a tappet, a first piston, a second piston, a first intake valve, a second intake valve, a first valve spring, and a second valve spring. The tappet compresses medium oil under the drive of the camshaft to build up pressure and drive the first piston and the second piston. The first piston drives the first intake valve, and the second piston drives the second intake valve. The first intake valve is equipped with a first valve spring; the second intake valve is equipped with a second valve spring; the first valve spring and the second valve spring are different and the diameters of the first piston and the second piston are different.

[0014] As a further technical solution, the first valve spring and the second valve spring are different including that the first valve spring and the second valve spring have exactly the same stiffness but different preload forces; or the first valve spring and the second valve spring have different stiffness but the same preload forces, or the first valve spring and the second valve spring have different stiffness and different preload forces.

[0015] As a further technical solution, the diameter of the first piston or the diameter of the second piston; the stiffness of the first valve spring or the stiffness of the second valve spring, and the preload force of the first valve spring or the preload force of the second valve spring are all calculated by the following formula: =

[0016]

[0017] Among them, F A0 is the spring preload of the first valve spring; F B0 is the spring preload of the second valve spring; K A is the stiffness of the first valve spring; K B is the stiffness of the second valve spring; L Amax L is the maximum lift of the intake valve at full opening; Bmax =L Amax -δ; δ is the maximum lift difference between the first intake valve and the second intake valve; according to the cross-sectional area S of the first piston A , the cross-sectional area S of the second piston B, and obtain the diameters of the first piston and the second piston. In a sixth aspect, the present invention provides an engine comprising the various engine hydraulic variable valve different lift mechanisms described above.

[0018] The beneficial effects of the present invention are as follows: In the engine hydraulic variable valve differential lift mechanism proposed by the present invention, the tappet compresses the medium oil under the drive of the camshaft to build up pressure, and the two pistons, driven by the oil pressure, follow different valve lift curves due to their different diameters; or follow different valve lift curves due to the difference in the two valve springs; or follow different valve lift curves due to the combined effect of different piston diameters and different valve springs. This method can achieve the generation of larger vortexes due to the different openings of the two intake valves, promote combustion mixing to a certain extent, and improve combustion efficiency. Compared with the existing technology, it has low cost and relatively small changes to the engine, which is conducive to the transformation and upgrading of existing models. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their description are used to explain the present invention and do not constitute a limitation of the present invention. It should also be understood that these drawings are shown for simplicity and clarity and are not necessarily drawn to scale. The present invention will now be described and explained with additional features and details through the use of the accompanying drawings, in which: Figure 1 The schematic diagram of the arrangement of the hydraulic variable valve different lift mechanism disclosed in the present invention is shown; Figure 2 The figure shows the appearance of the hydraulic variable valve different lift mechanism disclosed in the present invention; Figure 3 The valve lift in different states in the embodiment of the present invention is shown in FIG. Figure 1 ; Figure 4 The valve lift in different states in the embodiment of the present invention is shown in FIG. Figure 2 ; Figure 5 A schematic diagram of lift transmission relationship in an embodiment of the present invention is shown; In the figure: 1. first intake valve; 2. second intake valve; 3. valve spring seat; 4. first piston; 5. second piston; 6. tappet; 7. camshaft; 11. first valve spring; 12. second valve spring; DETAILED DESCRIPTION It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0020] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise explicitly stated in the present invention, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof; The purpose of this embodiment is to provide an engine hydraulic variable intake valve different lift mechanism and method to solve the problem of the existing four-valve engine's demand for hydraulic variable valve intake valve swirl intensity.

[0021] Example 1 In order to solve the problem of the existing four-valve engine's demand for the vortex strength of the hydraulic variable valve intake valve, this embodiment discloses an engine hydraulic variable intake valve different lift mechanism; Figure 1 As shown, it includes a pump body, a camshaft 7, a tappet 6, a first piston 4, a second piston 5, a first intake valve 1, a second intake valve 2, a first valve spring 11, a second valve spring 12 and a valve spring seat 3. The tappet 6 compresses the medium oil under the drive of the camshaft 7 to build up pressure and drive the first piston 4 and the second piston 5. The first piston 4 drives the first intake valve 1, and the second piston 5 drives the second intake valve 2. The first intake valve 1 is installed with the first valve spring 11; the second intake valve 2 is installed with the second valve spring 12. The first piston 4 needs to overcome the reaction force of the first valve spring 11 to push the first intake valve 1 to move; the second piston 5 needs to overcome the reaction force of the second valve spring 12 to push the second intake valve 2 to move; the first piston 4 and the second piston 5 have different valve lift curves due to their different diameters under the drive of oil pressure; Specifically, Figure 1 , Figure 2 , Figure 5 The hydraulic variable valve differential lift mechanism shown in the figure is mainly composed of a tappet 6 and two pistons (a first piston 4 and a second piston 5). The first piston 4 and the second piston 5 drive the two first intake valves 1 and the second intake valves 2 respectively. The first piston 4 drives the first intake valve 1, and the second piston 5 drives the second intake valve 2. In this embodiment, the first piston 4 and the second piston 5 are set to have different diameters. Since the pressure in the high-pressure chamber is the same, the output forces of the two pistons with different diameters are different, and the strokes acting on the first intake valve 1 and the second intake valve 2 are different, such as Figure 3 As shown, the lift curves of large and small lift valves not only differ in lift, but also in phase angle, thereby achieving the purpose of changing the vortex intensity.

[0022] In this embodiment, it is assumed that the diameter of the first piston 4 is d A , cross-sectional area is S A, lift is L A ; Cross-sectional area S A =πd A ² / 4.

[0023] The diameter of the second piston 5 is d B , the cross-sectional area is S B , lift is L B ; Cross-sectional area S B =πd B ² / 4.

[0024] The diameter of the tappet 6 is d T , the cross-sectional area is S T , lift is L T , the oil chamber pressure is P, and the stiffness of the first valve spring 11 is K A ; The stiffness of the second valve spring 12 is K B , the spring preload force of the first valve spring 11 is F A0 , the spring preload force of the second valve spring 12 is F B0 ; It is known that the maximum lift difference between the two intake valves (the first intake valve 1 and the second intake valve 2) is δ, and the maximum lift at the widest opening is L Amax , the diameter of the tappet 6 is d T and lift is L Tmax Then L Bmax =L Amax -δ.

[0025] According to the principle that the displacement of the tappet 6 is the same as the displacement of the piston:

[0026] According to the principle of balance between piston thrust and valve spring force:

[0027] Combining formula (2) and formula (3): =

[0028]

[0029] Substituting formula (1) into the above formula, we can solve for S A and S B , and then solve for the diameter d of the first piston 4 A and the diameter d of the second piston 5 B .

[0030] Compared with the prior art, the engine hydraulic variable intake valve differential lift mechanism provided in this embodiment has low cost and relatively small changes to the engine, which is conducive to the transformation and upgrading of existing models.

[0031] Example 2 In order to solve the problem of the existing four-valve engine's requirement for the vortex strength of the hydraulic variable valve intake valve, this embodiment discloses another engine hydraulic variable intake valve different lift mechanism; including a pump body, a camshaft 7, a tappet 6, a first piston 4, a second piston 5, a first intake valve 1, a second intake valve 2, a first valve spring 11, a second valve spring 12 and a valve spring seat 3, the tappet 6 compresses the medium oil under the drive of the camshaft 7 to build up pressure and drive the first piston 4 and the second piston 5, the first piston 4 drives the first intake valve 1, the second piston 5 drives the second intake valve 2, the first intake valve 1 is installed with a first valve spring 11; the second intake valve 2 is installed with a second valve spring 12; in this embodiment, the first piston 4 and the second piston 5 are set to the same diameter, and the valve difference is achieved by setting the first valve spring 11 and the second valve spring 12 to different springs; that is, different valve lift curves are produced due to the difference in the two valve springs; In this embodiment, the first valve spring 11 and the second valve spring 12 are different, including the first valve spring 11 and the second valve spring 12 having exactly the same stiffness but different preload forces, or the first valve spring 11 and the second valve spring 12 having different stiffness but the same preload forces, or the first valve spring 11 and the second valve spring 12 having different stiffness and different preload forces.

[0032] When the first valve spring 11 and the second valve spring 12 are set to springs with different stiffness, the spring stiffness can be adjusted by selecting different materials, different wire diameters, different center diameters, different effective numbers of turns and spring shapes.

[0033] Compared with the prior art, the engine hydraulic variable intake valve differential lift mechanism provided in this embodiment has low cost and relatively small changes to the engine, which is conducive to the transformation and upgrading of existing models.

[0034] The calculation method of the stiffness of the first valve spring 11, the stiffness of the second valve spring 12, and the preload of the first valve spring 11, and the preload of the second valve spring 12 in this embodiment can refer to the calculation method in Example 1; generally, the stiffness or preload of the first valve spring 11 or the second valve spring 12 is determined in advance, and then the stiffness or preload of the other valve spring is solved.

[0035] Example 3 In order to solve the problem of the existing four-valve engine's demand for the vortex intensity of the hydraulic variable valve intake valve, the present embodiment discloses another engine hydraulic variable intake valve different lift mechanism; it includes a pump body, a camshaft 7, a tappet 6, a first piston 4, a second piston 5, a first intake valve 1, a second intake valve 2, a first valve spring 11, a second valve spring 12 and a valve spring seat 3, the tappet 6 compresses the medium oil under the drive of the camshaft 7 to build up pressure and drive the first piston 4 and the second piston 5, the first piston 4 drives the first intake valve 1, the second piston 5 drives the second intake valve 2, the first intake valve 1 is installed with a first valve spring 11; the second intake valve 2 is installed with a second valve spring 12; in the present embodiment, the first piston 4 and the second piston 5 are set to different diameters, and the first valve spring 11 and the second valve spring 12 are set to different springs to achieve valve differences; that is, the valve lift difference curve is achieved by combining different piston diameters and different springs.

[0036] In this embodiment, the first valve spring 11 and the second valve spring 12 are configured as different springs, specifically, the first valve spring 11 and the second valve spring 12 are configured as springs with different stiffnesses; the spring stiffness can be adjusted by selecting different materials, different wire diameters, different center diameters, different effective numbers of turns and spring shapes.

[0037] Alternatively, in this embodiment, the first valve spring 11 and the second valve spring 12 have exactly the same stiffness but different preload forces, which also includes the first valve spring 11 and the second valve spring 12 having different stiffnesses and the same preload forces, and also includes the first valve spring 11 and the second valve spring 12 having different stiffnesses and different preload forces.

[0038] in, Figure 3 When the preload of the two valve springs is the same and the two piston diameters are different, the two valve phase angles and lifts will be different; or when the preload of the two valve springs is different and the two piston diameters are also different, the two valve phase angles and lifts will also be different. The same or different stiffness of the two valve springs only affects the difference in the lift of the two valves. Figure 4 When the two piston diameters are the same and the two valve spring preloads are the same, and only the valve spring stiffness is changed, the two valve phase angles are the same, but the valve lifts are different. Figure 3 A1 and A2 in the figure represent the phase angle corresponding to the small lift valve and the phase angle corresponding to the large lift valve respectively; Figure 4 A2 in the figure indicates the phase angle corresponding to the small lift valve when the phase angle is the same as the phase angle of the large lift valve; Compared with the prior art, the engine hydraulic variable intake valve differential lift mechanism provided in this embodiment has low cost and relatively small changes to the engine, which is conducive to the transformation and upgrading of existing models.

[0039] The calculation method of the diameter of the first piston 4 or the diameter of the second piston 5, the stiffness of the first valve spring 11, the stiffness of the second valve spring 12, and the preload force of the first valve spring 11, the preload force of the second valve spring 12 can be calculated by referring to the calculation method in Example 1.

[0040] Example 4 This embodiment provides an engine, which adopts the engine hydraulic variable intake valve different lift mechanism disclosed in Embodiment 1, Embodiment 2, and Embodiment 3. The engine includes the engine hydraulic variable intake valve different lift mechanism described above. Since the engine is provided with the engine hydraulic variable intake valve different lift mechanism described above, the engine also has all the advantages described above.

[0041] In the engine hydraulic variable valve differential lift mechanism proposed in the above embodiment, the tappet compresses the medium oil under the drive of the camshaft to build up pressure, and the two pistons follow different valve lift curves due to different diameters under the push of oil pressure; or follow different valve lift curves due to the difference in two valve springs; or follow different valve lift curves due to the combined effect of different piston diameters and different valve springs. Compared with the existing technology, this method has low cost and relatively small changes to the engine, which is conducive to the transformation and upgrading of existing models.

[0042] Finally, it should be noted that relational terms such as first and second are merely used to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An engine hydraulic variable intake valve different lift mechanism, comprising: Camshaft, tappet, first piston, second piston, first intake valve, second intake valve, first valve spring, second valve spring. Driven by the camshaft, the tappet compresses medium oil to build up pressure and drive the first piston and the second piston. The first piston drives the first intake valve and the second piston drives the second intake valve. The first intake valve is equipped with a first valve spring and the second intake valve is equipped with a second valve spring. It is characterized in that the first piston and the second piston have different diameters.

2. The engine hydraulic variable intake valve different lift mechanism according to claim 1, characterized in that: The cross-sectional area S of the first piston A , the cross-sectional area S of the second piston B Calculated by the following formula: = Among them, F A0 is the spring preload of the first valve spring; F B0 is the spring preload of the second valve spring; K A is the stiffness of the first valve spring; K B is the stiffness of the second valve spring; L Amax L is the maximum lift of the intake valve at full opening; Bmax =L Amax -δ; δ is the maximum lift difference between the first intake valve and the second intake valve; According to the cross-sectional area S of the first piston A , the cross-sectional area S of the second piston B , and obtain the diameters of the first piston and the second piston.

3. An engine, characterized in that: It includes the engine hydraulic variable intake valve different lift mechanism as described in any one of claims 1-2.

4. An engine hydraulic variable intake valve different lift mechanism, comprising: Camshaft, tappet, first piston, second piston, first intake valve, second intake valve, first valve spring, second valve spring. Driven by the camshaft, the tappet compresses medium oil to build up pressure and drive the first piston and the second piston. The first piston drives the first intake valve and the second piston drives the second intake valve. The first intake valve is equipped with a first valve spring and the second intake valve is equipped with a second valve spring. The characteristic is that the first valve spring and the second valve spring are different.

5. The engine hydraulic variable intake valve different lift mechanism as claimed in claim 4, characterized in that: The first valve spring and the second valve spring are different including that the first valve spring and the second valve spring have exactly the same stiffness but different preload forces; or the first valve spring and the second valve spring have different stiffness but the same preload forces, or the first valve spring and the second valve spring have different stiffness and different preload forces.

6. An engine, characterized in that: It includes the engine hydraulic variable intake valve different lift mechanism as described in any one of claims 4-5.

7. An engine hydraulic variable intake valve different lift mechanism, comprising: Camshaft, tappet, first piston, second piston, first intake valve, second intake valve, first valve spring, second valve spring. Driven by the camshaft, the tappet compresses medium oil to build up pressure and drive the first piston and the second piston. The first piston drives the first intake valve and the second piston drives the second intake valve. The first intake valve is equipped with a first valve spring and the second intake valve is equipped with a second valve spring. The first valve spring and the second valve spring are different and the diameters of the first piston and the second piston are different.

8. The engine hydraulic variable intake valve different lift mechanism as claimed in claim 7, characterized in that: The first valve spring and the second valve spring are different including that the first valve spring and the second valve spring have exactly the same stiffness but different preload forces; or the first valve spring and the second valve spring have different stiffness but the same preload forces, or the first valve spring and the second valve spring have different stiffness and different preload forces.

9. The engine hydraulic variable intake valve different lift mechanism as claimed in claim 7, characterized in that: The diameter of the first piston or the diameter of the second piston; the stiffness of the first valve spring or the stiffness of the second valve spring, and the preload force of the first valve spring or the preload force of the second valve spring are all calculated by the following formula: = Among them, F A0 is the spring preload of the first valve spring; F B0 is the spring preload of the second valve spring; K A is the stiffness of the first valve spring; K B is the stiffness of the second valve spring; L Amax L is the maximum lift of the intake valve at full opening; Bmax =L Amax -δ; δ is the maximum lift difference between the first intake valve and the second intake valve; according to the cross-sectional area S of the first piston A , the cross-sectional area S of the second piston B , and obtain the diameters of the first piston and the second piston.

10. An engine, characterized in that: It includes the engine hydraulic variable intake valve different lift mechanism as described in any one of claims 7-9.

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