Intake pipe structure and internal combustion engine
By designing the intake pipe structure, including the main intake pipe, the first intake manifold, the second intake manifold, and the branch intake pipes, and by using a flow regulating valve to adjust the swirl ratio, the problem of poor combustion efficiency of internal combustion engines under different speeds and loads was solved, thereby improving combustion efficiency and stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- WEICHAI POWER CO LTD
- Filing Date
- 2025-06-27
- Publication Date
- 2026-07-21
AI Technical Summary
The intake structure of existing internal combustion engines cannot actively adjust the swirl ratio, resulting in poor combustion efficiency at different speeds and loads, leading to problems such as deteriorated combustion, poor gas consumption, and high exhaust temperature.
Design an intake pipe structure including an intake main pipe, a first intake manifold, a second intake manifold, and branch intake pipes. Adjust the swirl ratio by setting a flow regulating valve to meet the combustion requirements under different speeds and loads.
By adjusting the swirl ratio, the combustion efficiency of the internal combustion engine is improved, avoiding combustion degradation, poor gas consumption, and exhaust temperature problems, thereby enhancing the stability and efficiency of the combustion process.
Smart Images
Figure CN224532858U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of internal combustion engine technology, and in particular to an intake manifold structure and an internal combustion engine. Background Technology
[0002] Swirl intensity is a core parameter affecting combustion. At specific engine speeds and loads, there exists an optimal swirl ratio: a too-small swirl ratio results in slow flame propagation, slow combustion, and low thermal efficiency. As the swirl ratio increases, combustion speed accelerates and thermal efficiency improves; however, if the swirl ratio is too large, in-cylinder heat transfer increases dramatically, leading to increased heat loss and a decrease in thermal efficiency. Figure 1 As shown.
[0003] Swirl ratio intensity is a key parameter affecting the combustion speed of premixed spark-ignition gas engines. The swirl ratio requirement for combustion varies with engine speed and load, while the intake manifold structure of existing gas engines is fixed. During the intake process, an in-cylinder swirl is formed by guidance through the intake manifold. Common intake manifold structures that form swirls include tangential intake manifolds (O1) and spiral intake manifolds (O2). For example... Figure 2 and Figure 3 As shown, the tangential intake duct 01 guides the airflow into the cylinder along the cylinder tangential direction. Guided by the cylinder wall, the airflow forms a vortex rotating along the cylinder's central axis. For example... Figure 4 and Figure 5 As shown, the spiral intake duct 02 causes the airflow to generate a spiral motion within the intake duct. The intake duct outlet direction is tangential to the cylinder wall, and a circumferential vortex is formed by the guidance of the cylinder wall. The vortex is formed by the flow velocity of the intake airflow and the guidance of the cylinder wall.
[0004] It is evident that vortex intensity is positively correlated with intake airflow and negatively correlated with cylinder diameter. For the same internal combustion engine, since the cylinder diameter is fixed, vortex intensity is only positively correlated with intake airflow.
[0005] For internal combustion engines, the required swirl ratio varies under different engine speeds and loads. Current gas engine cylinder head structures are fixed and lack active adjustment capabilities for swirl ratio intensity. The swirl ratio intensity is only positively correlated with the intake airflow rate, and its variation characteristics differ from the required swirl characteristics under different engine speeds and operating conditions. Therefore, it is difficult to meet the swirl ratio requirements of combustion at different speeds and loads, leading to problems such as poor combustion, low fuel consumption, and high exhaust temperatures in gas engines. Utility Model Content
[0006] The first objective of this invention is to provide an intake manifold structure that can meet the combustion requirements for swirl ratio under different speeds and loads, thereby avoiding problems such as poor combustion, low gas consumption, and high exhaust temperature in internal combustion engines.
[0007] The second objective of this invention is to provide an internal combustion engine including the above-described intake manifold structure.
[0008] To achieve the above objectives, this utility model provides the following technical solution:
[0009] An intake manifold structure includes an intake main, a first intake manifold, a second intake manifold, and a branch intake manifold. The first ends of the first and second intake manifolds are connected in parallel to the intake main, and the second ends of the first and second intake manifolds are connected to a cylinder. The first intake manifold is a tangential intake passage or a helical intake passage. The first end of the branch intake manifold is connected to the intake main, and the second end of the branch intake manifold is connected to the second intake manifold on the side of the second intake manifold away from the first intake manifold. The branch intake manifold is equipped with a flow regulating valve.
[0010] In one embodiment of this application, the pipe diameter ratio d / D of the equivalent diameter d of the branch intake pipe and the equivalent diameter D of the main intake pipe satisfies 0 < d / D ≤ 0.5.
[0011] In one embodiment of this application, the line connecting the center of the outlet end of the second intake manifold and the center of the intake end of the second intake manifold is the centerline of the second intake manifold. The straight line passing through the center of the outlet end of the branch intake pipe and perpendicular to the end face of the outlet end of the branch intake pipe is the outlet end extension line of the branch intake pipe. The angle α between the centerline of the second intake manifold and the outlet end extension line of the branch intake pipe satisfies 15°≤α≤90°.
[0012] In one embodiment of this application, the distance L between the extension line of the outlet end of the branch intake pipe and the center line of the outlet end of the second intake manifold is greater than 0 and less than or equal to a preset distance upstream of the parallel position of the second intake manifold and the first intake manifold.
[0013] In one embodiment of this application, the preset distance is 2D, where D is the equivalent diameter of the intake manifold.
[0014] In one embodiment of this application, the branch intake pipe is connected to the second intake manifold at a position where the second intake manifold and the first intake manifold are connected in parallel, or the branch intake pipe is connected to the second intake manifold at a position where the second intake manifold and the first intake manifold are connected and at a position where the second intake manifold and the main intake pipe are connected.
[0015] In one embodiment of this application, the flow regulating valve is communicatively connected to an internal combustion engine controller, and the internal combustion engine controller is used to control the working state of the flow regulating valve according to the internal combustion engine intake air volume detection value.
[0016] In one embodiment of this application, the cross-sectional shape of the branch intake pipe is circular, elliptical, or rectangular.
[0017] In one embodiment of this application, the branch intake pipe is a heat-resistant rigid pipe or a heat-resistant flexible pipe.
[0018] An internal combustion engine comprising an intake manifold structure as described in any of the above claims.
[0019] As can be seen from the above technical solutions, this utility model discloses an intake pipe structure, which includes an intake manifold, a first intake manifold, a second intake manifold, and a branch intake pipe. The first ends of the first and second intake manifolds are connected in parallel to the intake manifold, and the second ends of the first and second intake manifolds are connected to the cylinder. The first intake manifold is a tangential intake passage or a spiral intake passage. The first end of the branch intake pipe is connected to the intake manifold, and the second end of the branch intake pipe is connected to the second intake manifold on the side of the second intake manifold away from the first intake manifold. The branch intake pipe is equipped with a flow regulating valve, and the opening degree of the flow regulating valve is related to the operating conditions.
[0020] In application, when the intake air volume of the internal combustion engine is low, the in-cylinder swirl ratio is low. At this time, by opening the flow control valve and adjusting its opening to the maximum, the airflow in the branch intake manifold impacts the airflow in the second intake manifold at a certain angle, changing the airflow direction in the second intake manifold and deflecting it towards the first intake manifold. This results in the airflow rate in the first intake manifold being greater than that in the second intake manifold, allowing as much airflow as possible to enter the cylinder from the first intake manifold. Since most of the airflow is guided in the first intake manifold, it easily forms a swirl in the cylinder, thus increasing the swirl ratio. As the intake air volume of the internal combustion engine increases, the in-cylinder swirl intensity gradually increases. At this time, the opening of the flow control valve is gradually reduced until it is completely closed to avoid an excessively high swirl ratio.
[0021] As can be seen from the above-mentioned intake pipe structure, the opening of the flow regulating valve can be controlled according to the intake air volume of the internal combustion engine, thereby adjusting the swirl ratio. This makes the swirl variation characteristics more closely match the swirl characteristics required by the internal combustion engine under different speeds and operating conditions, so as to meet the combustion requirements for the swirl ratio under different speeds and loads, and avoid problems such as poor combustion, poor gas consumption, and high exhaust temperature in the internal combustion engine. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 The graph shows the relationship between the eddy current ratio and thermal efficiency, in-cylinder heat transfer, and thermal efficiency.
[0024] Figure 2 This is a front view of the tangential air intake.
[0025] Figure 3 This is a top view of the tangential air intake.
[0026] Figure 4 This is a front view of the spiral air intake.
[0027] Figure 5 This is a top view of the spiral air intake.
[0028] Figure 6 This is a schematic diagram of the intake pipe structure provided in an embodiment of the present utility model;
[0029] Figure 7 A top view of the intake pipe structure provided in an embodiment of this utility model;
[0030] Figure 8 This is a graph showing the relationship between the vortex ratio and the intake air volume of an internal combustion engine after adopting the intake pipe structure provided in this embodiment of the utility model.
[0031] Figures 2 to 5 middle:
[0032] 01 is a tangential air intake; 02 is a spiral air intake.
[0033] Figure 6 and Figure 7 middle:
[0034] 1 is the first intake manifold; 2 is the second intake manifold; 3 is the branch intake manifold; 4 is the cylinder; 5 is the exhaust manifold. Detailed Implementation
[0035] One of the core features of this invention is to provide an intake pipe structure. The structural design of this intake pipe structure enables it to meet the combustion requirements for swirl ratio under different speeds and loads, thereby avoiding problems such as deteriorated combustion, poor gas consumption, and high exhaust temperature in internal combustion engines.
[0036] Another core aspect of this invention is to provide an internal combustion engine that includes the aforementioned intake manifold structure.
[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0038] Please see Figure 6 and Figure 7 , Figure 6 This is a schematic diagram of the intake pipe structure provided in an embodiment of the present utility model. Figure 7 This is a top view of the intake pipe structure provided in an embodiment of the present utility model.
[0039] This utility model discloses an intake pipe structure for connecting to the cylinder head of an internal combustion engine and supplying air to the combustion chamber of the internal combustion engine during operation. The intake pipe structure includes an intake main pipe, a first intake manifold 1, a second intake manifold 2, and a branch intake pipe 3.
[0040] The intake manifold and branch intake manifolds 3 can be made of metal or durable plastic. The first intake manifold 1 and the second intake manifold 2 are usually made of metal, including but not limited to cast iron and aluminum alloy. An air filter is usually installed on the intake manifold to guide the intake airflow through the air filter. If the internal combustion engine is a turbocharged internal combustion engine, an intercooler is usually also installed on the intake manifold. The first intake manifold 1 and the second intake manifold 2 are connected to the same cylinder 4 as a group. The intake manifold can connect to multiple groups of first intake manifolds 1 and second intake manifolds 2 at the same time. For example, when the internal combustion engine is a four-cylinder internal combustion engine, the intake manifold can connect to four groups of first intake manifolds 1 and second intake manifolds 2 at the same time.
[0041] The first intake manifold 1 and the first ends of the second intake manifold 2 are connected in parallel to the intake main pipe. The outlet end of the intake main pipe is connected to the first end (intake end) of the first intake manifold 1 and the second intake manifold 2 respectively. The second ends (outlet ends) of the first intake manifold 1 and the second intake manifold 2 are connected to the cylinder 4. The first intake manifold 1 is a tangential intake passage or a spiral intake passage, which is used to guide the airflow to form an organized rotating airflow, i.e., a vortex, in the cylinder 4. During the operation of the internal combustion engine, the fuel is injected into the combustion chamber in the direction of the vortex. Under the action of the vortex, it quickly diffuses and evaporates and mixes with the airflow. After the fuel is ignited, the flame can quickly spread throughout the entire combustion chamber with the rotation of the vortex. This can effectively promote the mixing of fuel and air, optimize the combustion process, prevent the internal combustion engine from surging, and form a low-pressure zone in the central part, which is beneficial to ignition and flame stability.
[0042] On the other side of the first intake manifold 1 and the second intake manifold 2, cylinder 4 is connected to an exhaust manifold 5, through which exhaust gases generated during combustion in the combustion chamber of cylinder 4 are discharged.
[0043] The first end of the branch intake pipe 3 is connected to the main intake pipe, and the second end of the branch intake pipe 3 is connected to the second intake manifold 2 on the side away from the first intake manifold 1. The branch intake pipe 3 is equipped with a flow regulating valve, the opening degree of which is related to the operating conditions. According to the overall layout of the internal combustion engine, the branch intake pipe 3 can be a straight pipe, a curved pipe or a bend pipe, or a combination of a straight pipe and a curved pipe or a bend pipe.
[0044] The branch intake pipe 3 can be a heat-resistant rigid pipe or a heat-resistant flexible pipe, or part of it can be a heat-resistant rigid pipe and the rest can be a heat-resistant flexible pipe. That is, the branch intake pipe 3 can be formed by sealing and connecting at least one heat-resistant rigid pipe and at least one heat-resistant flexible pipe. The cross-sectional shape of the branch intake pipe 3 can be of various shapes, including but not limited to circular, elliptical or rectangular. The branch intake pipe 3 can be a pipe with a constant cross-sectional area from one end to the other, or it can be a pipe with a variable cross-sectional area and / or shape that is different from the other part.
[0045] In application, when the intake air volume of the internal combustion engine is low, the in-cylinder swirl ratio is low. At this time, by opening the flow control valve and adjusting its opening to the maximum, the airflow in the branch intake pipe 3 impacts the airflow in the second intake manifold 2 at a certain angle, changing the airflow direction in the second intake manifold 2 and deflecting the airflow towards the first intake manifold 1. This results in the airflow rate in the first intake manifold 1 being greater than the airflow rate in the second intake manifold 2, allowing as much airflow as possible to enter the cylinder 4 from the first intake manifold 1. Since most of the airflow is guided in the first intake manifold 1, it easily forms a swirl in the cylinder 4, thereby increasing the swirl ratio. As the intake air volume of the internal combustion engine increases, the in-cylinder swirl intensity also gradually increases. At this time, the opening of the flow control valve is gradually reduced until it is completely closed to avoid an excessively large swirl ratio.
[0046] like Figure 8 As shown, Figure 8 The dashed line represents the relationship between vortex ratio and internal combustion engine intake volume in the prior art, while the solid line represents the relationship between vortex ratio and internal combustion engine intake volume after adopting the intake pipe structure provided in this application embodiment. It can be seen that when the internal combustion engine intake volume is small, the opening of the flow regulating valve is the largest. The vortex ratio formed by the intake pipe structure provided in this application embodiment is greater than the vortex ratio formed by the intake pipe structure in the prior art. As the internal combustion engine intake volume increases, the opening of the flow regulating valve gradually decreases, and the vortex ratio formed by the intake pipe structure provided in this application embodiment gradually becomes consistent with the vortex ratio formed by the intake pipe structure in the prior art.
[0047] Compared with the prior art, the intake pipe structure provided by this utility model embodiment can control the opening of the flow regulating valve according to the intake air volume of the internal combustion engine, thereby adjusting the swirl ratio. This makes the swirl change characteristics more closely match the swirl characteristics required by the internal combustion engine under different speeds and operating conditions, so as to meet the combustion requirements for the swirl ratio under different speeds and loads, and avoid problems such as poor combustion, poor gas consumption, and high exhaust temperature of the internal combustion engine.
[0048] Specifically, in one embodiment of this application, the pipe diameter ratio d / D of the equivalent diameter d of the branch intake pipe 3 and the equivalent diameter D of the intake main pipe satisfies 0 < d / D ≤ 0.5, and the size of the pipe diameter ratio d / D is positively correlated with the adjustment capability of the vortex ratio.
[0049] It should be noted that the formula for calculating the equivalent diameter is as follows:
[0050] Equivalent diameter = 4 × pipe cross-sectional area / pipe cross-sectional perimeter.
[0051] The equivalent diameter d of the branch intake pipe 3 and the equivalent diameter D of the main intake pipe are both calculated using the above formula.
[0052] Preferably, the line connecting the center of the outlet end of the second intake manifold 2 and the center of the intake end of the second intake manifold 2 is the centerline of the second intake manifold 2, and the straight line passing through the center of the outlet end of the branch intake pipe 3 and perpendicular to the end face of the outlet end of the branch intake pipe 3 is the extension line of the outlet end of the branch intake pipe 3. The angle α between the centerline of the second intake manifold 2 and the extension line of the outlet end of the branch intake pipe 3 satisfies 15°≤α≤90°.
[0053] like Figure 7 As shown, when 15°≤α≤45°, the angle between the branch intake pipe 3 and the second intake manifold 2 is small. The airflow in the branch intake pipe 3 mainly increases the airflow rate in the second intake manifold 2. Since the second intake manifold 2 does not guide the airflow to form a vortex, the increase in the airflow rate in the second intake manifold 2 has a small effect on enhancing the vortex ratio. When 45°≤α≤90°, the angle between the branch intake pipe 3 and the second intake manifold 2 is large. The airflow in the branch intake pipe 3 mainly increases the airflow rate in the first intake manifold 1. Since the first intake manifold 1 is a tangential intake or a spiral intake, the increase in the airflow rate in the first intake manifold 1 has a greater effect on enhancing the vortex ratio.
[0054] Further optimize the above technical solutions, such as Figure 8 As shown, the distance L between the extension line of the outlet end of the branch intake pipe 3 and the center line of the outlet end of the second intake manifold 2 is greater than 0 and less than or equal to the preset distance upstream of the parallel position of the second intake manifold 2 and the first intake manifold 1. In the actual design process, the specific value of L is determined according to the actual flow rate and swirl ratio requirements of the internal combustion engine.
[0055] Specifically, in one embodiment of this application, the aforementioned preset distance is 2D, where D is the equivalent diameter of the intake manifold.
[0056] Preferably, in one embodiment of this application, the branch intake pipe 3 and the second intake manifold 2 are connected at the position where the second intake manifold 2 and the first intake manifold 1 are connected in parallel, or the branch intake pipe 3 and the second intake manifold 2 are connected between the position where the second intake manifold 2 and the first intake manifold 1 are connected in parallel and the position where the second intake manifold 2 and the main intake pipe are connected.
[0057] To precisely control the flow regulating valve so that its opening is inversely related to the intake air volume of the internal combustion engine, in one embodiment of this application, the flow regulating valve is communicatively connected to the internal combustion engine controller. The internal combustion engine controller controls the working state of the flow regulating valve based on the detected intake air volume value of the internal combustion engine. As the intake air volume increases, the internal combustion engine controller gradually reduces the opening of the flow regulating valve until the flow regulating valve is closed. It should be noted that the change in the opening of the flow regulating valve and the increase or decrease in the intake air volume can be linear or non-linear, and can be set according to the actual working conditions of the internal combustion engine.
[0058] This application also provides an internal combustion engine, which includes the intake manifold structure as described in the above embodiments. Since the internal combustion engine adopts the intake manifold structure in the above embodiments, the technical effect of the internal combustion engine can be referred to the above embodiments. The internal combustion engine provided in this application includes, but is not limited to, gas engines, gasoline engines, and diesel engines.
[0059] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.
[0060] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.
[0061] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0062] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.
Claims
1. An intake pipe structure, characterized in that, It includes an intake manifold, a first intake manifold (1), a second intake manifold (2), and a branch intake pipe (3). The first ends of the first intake manifold (1) and the second intake manifold (2) are connected in parallel to the intake manifold. The second ends of the first intake manifold (1) and the second intake manifold (2) are connected to the cylinder (4). The first intake manifold (1) is a tangential intake passage or a spiral intake passage. The first end of the branch intake pipe (3) is connected to the intake manifold. The second end of the branch intake pipe (3) is connected to the second intake manifold (2) on the side of the second intake manifold (2) away from the first intake manifold (1). The branch intake pipe (3) is equipped with a flow regulating valve.
2. The intake pipe structure according to claim 1, characterized in that, The pipe diameter ratio d / D of the equivalent diameter d of the branch intake pipe (3) and the equivalent diameter D of the main intake pipe satisfies 0 < d / D ≤ 0.
5.
3. The intake pipe structure according to claim 1, characterized in that, The line connecting the center of the outlet end of the second intake manifold (2) and the center of the intake end of the second intake manifold (2) is the centerline of the second intake manifold (2). The straight line passing through the center of the outlet end of the branch intake pipe (3) and perpendicular to the end face of the outlet end of the branch intake pipe (3) is the extension line of the outlet end of the branch intake pipe (3). The angle α between the centerline of the second intake manifold (2) and the extension line of the outlet end of the branch intake pipe (3) satisfies 15°≤α≤90°.
4. The intake pipe structure according to claim 3, characterized in that, The distance L between the extension line of the outlet end of the branch intake pipe (3) and the center line of the outlet end of the second intake manifold (2) is greater than 0 and less than or equal to the preset distance upstream of the parallel position of the second intake manifold (2) and the first intake manifold (1).
5. The intake pipe structure according to claim 4, characterized in that, The preset distance is 2D, where D is the equivalent diameter of the intake manifold.
6. The intake pipe structure according to claim 4, characterized in that, The branch intake pipe (3) is connected to the second intake manifold (2) at the parallel position of the second intake manifold (2) and the first intake manifold (1), or the branch intake pipe (3) is connected to the second intake manifold (2) at the parallel position of the second intake manifold (2) and the first intake manifold (1) and the position where the second intake manifold (2) is connected to the main intake pipe.
7. The intake pipe structure according to any one of claims 1-6, characterized in that, The flow regulating valve is communicatively connected to the internal combustion engine controller, which controls the working state of the flow regulating valve based on the detected intake air volume of the internal combustion engine.
8. The intake pipe structure according to any one of claims 1-6, characterized in that, The cross-sectional shape of the branch intake pipe (3) is circular, elliptical or rectangular.
9. The intake pipe structure according to any one of claims 1-6, characterized in that, The branch intake pipe (3) is a heat-resistant rigid pipe or a heat-resistant flexible pipe.
10. An internal combustion engine, characterized in that, Includes the intake pipe structure as described in any one of claims 1-9.