Exhaust pipe based on binder injection additive manufacturing
By using binder-jet additive manufacturing technology based on a three-cycle minimal curved surface structure, the inner wall of the exhaust pipe and the noise reduction baffle were designed, solving the problems of insufficient heat dissipation and noise pollution in the exhaust pipe under high temperature environment, achieving efficient heat dissipation and noise reduction effect, which is suitable for automotive and industrial emissions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-03
- Publication Date
- 2026-03-27
AI Technical Summary
Existing exhaust pipes fail to dissipate heat effectively in high-temperature and harsh environments, leading to component deformation, thermal damage, and the risk of spontaneous combustion, as well as severe noise pollution. Existing technologies are unable to effectively solve these problems.
Adhesive jet additive manufacturing technology based on a three-period minimal curved surface structure was used to design the inner wall of the exhaust pipe and the noise reduction baffle. Combined with the external heat dissipation structure, the exhaust pipe was fabricated by utilizing the high specific surface area and pore connectivity of the minimal curved surface through adhesive jet additive manufacturing technology.
It improves the heat dissipation capacity of the exhaust pipe, reduces noise pollution, extends service life, and reduces exhaust gas pollution levels, making it suitable for automotive and industrial gas emissions.
Smart Images
Figure CN224049292U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application relates to the technical field of exhaust pipe heat dissipation, and particularly relates to an exhaust pipe based on binder jetting additive manufacturing. BACKGROUND
[0002] An exhaust system is a key part of a vehicle as a whole, and its main function is to discharge exhaust gas generated during engine operation, reduce exhaust gas pollution, reduce noise, and ultimately ensure the comfort of the vehicle during driving. As a main core component of the engine exhaust system, the exhaust pipe is in a harsh environment with long-term pollution and repeated high temperature. If the heat dissipation is insufficient, heat accumulation may cause deformation of parts, thermal damage to surrounding parts (such as burning out of wiring harnesses or vehicle body coatings), and even cause spontaneous combustion risk. Therefore, improving the exhaust pipe's ability to discharge pollutants and dissipate heat in a high-temperature harsh environment has important influence on its service life.
[0003] A triply periodic minimal surface (TPMS) is a special surface structure that is periodically repeated in three dimensions and has a zero average curvature characteristic. The TPMS structure has a highly connected smooth implicit surface and a high specific surface area, which endow it with excellent energy absorption and efficient heat exchange properties, and can provide great application value in the heat dissipation of exhaust pipe components. CONTENT OF THE UTILITY MODEL
[0004] In order to solve the heat dissipation problem of the exhaust pipe, the application based on the triply periodic minimal surface structure provides an exhaust pipe based on binder jetting additive manufacturing. The inner wall of the exhaust pipe body composed of the triply periodic minimal surface structure has excellent energy absorption and heat exchange capacity when the gas flows through the inner wall, so that the exhaust pipe has excellent heat dissipation effect. The specific scheme adopted is as follows:
[0005] An exhaust pipe based on binder jetting additive manufacturing, comprising a hollow exhaust pipe body, the exhaust pipe body comprising a pipe wall and an inner cavity surrounded by the pipe wall; the pipe wall comprises an inner wall and an outer wall, the inner wall comprises a pipe body composed of a triply periodic minimal surface structure, and the outer wall is sleeved on the periphery of the inner wall to prevent gas from escaping outward in the circumferential direction through the minimal surface structure.
[0006] Preferably, a plurality of noise reduction baffles are further included, the noise reduction baffles are distributed in the inner cavity of the exhaust pipe body in the axial direction of the exhaust pipe body; the noise reduction baffles comprise baffles composed of a triply periodic minimal surface structure, and can reduce the flow speed of the gas in the inner cavity.
[0007] Preferably, the plane where the noise reduction baffle is located is perpendicular to the axial direction of the exhaust pipe body.
[0008] Preferably, the outer wall is circumferentially provided with a heat dissipation structure, and the heat dissipation structure comprises heat dissipation fins.
[0009] Preferably, the inner wall further comprises two connecting ends, and the connecting ends are located at two ends of the tubular body formed by the minimal surface structure and are respectively connected with an air inlet or an air outlet.
[0010] Preferably, the noise reduction baffle is integrally formed with the inner wall and is prepared by a binder jet additive manufacturing technology.
[0011] Preferably, at least one of the minimal surface structure unit of the tubular body and the minimal surface structure unit of the baffle adopts the following model equation:
[0012] ;
[0013] l is the size of the minimal surface structure unit.
[0014] Preferably, at least one of the minimal surface structure unit of the tubular body and the minimal surface structure unit of the baffle adopts the following model equation:
[0015] ;
[0016] l is the size of the minimal surface structure unit.
[0017] Preferably, at least one of the minimal surface structure unit of the tubular body and the minimal surface structure unit of the baffle adopts the following model equation:
[0018] ;
[0019] ;
[0020] l is the size of the minimal surface structure unit.
[0021] Preferably, the porosity of the inner wall decreases in the flow direction of the gas, or / and the porosity of the noise reduction baffle decreases.
[0022] The beneficial effects of the present application are as follows:
[0023] The exhaust pipe of the utility model adopts the design idea of minimal surface porous structure, the structure has the smooth surface of hole height intercommunication and the characteristics of high specific surface area, these characteristics endow the corresponding structure with excellent energy absorption capacity and high efficient heat transfer capacity, combined with the utilization of external heat dissipation structure, the exhaust pipe can maximize the exhaust and heat dissipation capacity for the pollution exhaust gas, and prolong the service life.
[0024] The noise reduction baffle designed by the minimal surface porous structure can effectively inhibit the gas flow velocity and reduce the generated noise when the exhaust gas flow passes through the baffle, and reduce the vibration damage caused by the noise.
[0025] The unit size and porosity parameters of the minimal surface structure unit can also be used to adjust the overall structure and mechanical strength of the internal minimal surface structure according to different actual road conditions, such as along the flow direction of the gas, the porosity decreasing structure design prolongs the residence time of the exhaust gas in the pipe, enhances the exhaust treatment effect, and can maximize the reduction of the pollution degree of the exhaust gas; at the same time, the exhaust noise is reduced, which has important significance for improving the environmental quality.
[0026] The exhaust pipe assembly body of the utility model is prepared by using the current mainstream binder jetting additive manufacturing technology, which can be applied to the preparation of commonly used metals and alloys such as aluminum alloy, iron alloy and the like, and has wide application. BRIEF DESCRIPTION OF DRAWINGS
[0027] Figure 1 is the exhaust pipe assembly body structure schematic diagram of the utility model;
[0028] Figure 2 is the exhaust pipe assembly body structure explosion view of the utility model;
[0029] Figure 3 is the calculation schematic diagram of the porosity p value of the minimal surface structure unit;
[0030] Figure 4 is the schematic diagram of the minimal surface structure unit;
[0031] Figure 5 is the noise reduction baffle setting mode schematic diagram in the exhaust pipe inner cavity;
[0032] Figure 6 is Figure 5 the enlarged schematic diagram of the partial structure in. DETAILED DESCRIPTION
[0033] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings of the present application. Obviously, the embodiments described in the present application are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.
[0034] In combination with Figure 1 and Figure 2An exhaust pipe based on binder jetting additive manufacturing, comprising a hollow exhaust pipe body, the exhaust pipe body comprising a pipe wall and an inner cavity surrounded by the pipe wall; the pipe wall comprising an inner wall 3 and an outer wall 4, the inner wall 3 comprising a pipe body composed of a three-period minimal surface structure, the outer wall 4 being sleeved on the periphery of the inner wall 3 to prevent gas from escaping outward in the circumferential direction through the minimal surface structure.
[0035] Referring to Figure 5 , the exhaust pipe further comprises noise reduction baffles 5, which are spaced apart along the axial direction of the exhaust pipe body in the inner cavity of the exhaust pipe body; the noise reduction baffles 5 comprise baffles composed of a three-period minimal surface structure, and after the gas enters the inner cavity of the exhaust pipe body, it passes through a series of noise reduction baffles to achieve layer-by-layer buffering, reduce the gas flow speed and air flow disturbance, thereby achieving the effect of noise reduction.
[0036] As Figure 5 and Figure 6 , the plane of the noise reduction baffle is perpendicular to the axial direction of the exhaust pipe body; the noise reduction baffle can also be arranged in a manner inclined to the axial direction of the exhaust pipe body.
[0037] The inner wall 3 and the noise reduction baffle 5 can also use other porous structures in addition to the minimal surface structure, and the minimal surface structure has the characteristics of smooth surface with hole height communication and high specific surface area, which performs relatively more excellent in exhaust pipe heat dissipation and noise reduction.
[0038] Referring to Figure 1 and Figure 2 , the outer wall is provided with a heat dissipation structure in the circumferential direction, and the heat dissipation structure comprises, but is not limited to, heat dissipation fins, heat dissipation pipes or heat dissipation coatings surrounding the outer wall.
[0039] Referring to Figure 1 , in order to facilitate gas flow, the inner wall further comprises two connecting ends, the connecting ends being located at both ends of the pipe body composed of the minimal surface structure and being respectively connected with the gas inlet 1 or the gas outlet 6.
[0040] Referring to Figure 2 , the connecting end of the inner wall can be connected with the gas inlet 1 or the gas outlet 6 through fasteners such as bolts and pins; the connecting end of the inner wall can also be connected with the gas inlet 1 or the gas outlet 6 through welding.
[0041] In order to improve production efficiency, the noise reduction baffle is integrally formed with the inner wall and is prepared by a binder jet additive manufacturing technology. As a mainstream additive manufacturing technology at present, the binder jet additive manufacturing technology can be widely applied to the development and manufacturing of parts made of metal, alloy, ceramic and other materials. In the embodiment, the inner wall and the noise reduction baffle can be made of at least one of 316L stainless steel, aluminum alloy, magnesium alloy, iron alloy, silicon carbide metal matrix composite, titanium carbide metal matrix composite and titanium nitride metal matrix composite.
[0042] The outer wall and the inner wall can be connected by welding, and the outer wall can also be directly attached to the outer side of the inner wall.
[0043] At least one of the minimal surface structure unit of the pipe body and the minimal surface structure unit of the noise reduction baffle adopts the following A model equation:
[0044] .
[0045] At least one of the minimal surface structure unit of the pipe body and the minimal surface structure unit of the noise reduction baffle adopts the following B model equation:
[0046] .
[0047] Wherein, l is the size of the minimal surface structure unit, x, y, z are the coordinate position points of the minimal surface structure unit in three-dimensional direction. When f=0, the function surface of the minimal surface structure unit is obtained;
[0048] As shown in Figure 4 , the isometric view is a view seen from the orthogonal 45° direction; the side view is a view seen from the left and right side; the plan / section view is a view seen from the top / bottom surface of the structure unit; both the A and B minimal surface unit structures have a highly connected smooth surface, and the high specific surface area of these surfaces has a good fluid flow effect, which can effectively reduce the flow speed of the exhaust gas flow and reduce noise and vibration noise energy.
[0049] As shown in Figure 3 , the minimal surface structure unit is designed based on a cubic structure, and the length, width and height of the structure unit all adopt a consistent size, i.e. the size of the minimal surface structure unit. The difference between the volume (V lattice ) of the minimal surface structure unit and the volume (V solid ) of the corresponding cubic entity with the same unit length is the pore area volume (V pore ) of the minimal surface structure unit inside the cubic frame.
[0050] The ratio of the pore area volume of the minimal surface structure unit to the volume of the cube entity with the corresponding unit edge length is denoted as porosity ρ (ρ = V pore / V solid )。
[0051] In this embodiment, the size of the minimal surface unit structure is 10 mm; the porosity of the minimal surface unit structure A is 0.6, and the porosity of the minimal surface unit structure B is 0.4.
[0052] Referring to Figure 3 to Figure 5 In this embodiment, the minimal surface structure unit of the pipe body adopts the B model equation, and the minimal surface structure unit of the noise reduction baffle adopts the A model equation.
[0053] In other embodiments, the minimal surface structure unit of the pipe body can also adopt the A model equation, and the minimal surface structure unit of the noise reduction baffle can adopt the B model equation.
[0054] In some embodiments, the porosity of the inner wall decreases in the flow direction of the gas, for example, the porosity of the inner wall decreases from 0.6 to 0.4; the porosity of the noise reduction baffle decreases, and the decrease can be an arithmetic decrease according to the actual number of baffles, that is, the porosity of adjacent noise reduction baffles decreases. Whether the porosity of the inner wall or the porosity of the noise reduction baffle is kept above 0.2 as much as possible.
[0055] The exhaust pipe described in the present application is suitable for automobile exhaust emission and also suitable for gas emission in industrial production scenes.
Claims
1. An exhaust pipe based on binder jet additive manufacturing, comprising a hollow exhaust pipe body, the exhaust pipe body comprising a pipe wall and an inner cavity enclosed by the pipe wall; characterized in that: The pipe wall comprises an inner wall and an outer wall, the inner wall comprises a pipe body composed of a three-period minimal surface structure, and the outer wall is sleeved on the periphery of the inner wall to prevent gas from escaping outward in the circumferential direction through the minimal surface structure.
2. The binder jet additive manufactured exhaust pipe of claim 1, wherein: The exhaust pipe body further comprises a plurality of noise reduction baffles, which are spaced apart along the axial direction of the exhaust pipe body and arranged in the inner cavity of the exhaust pipe body; the noise reduction baffles comprise baffles composed of a three-period minimal surface structure, which can reduce the flow speed of gas in the inner cavity.
3. The binder jet additive manufactured exhaust pipe of claim 2, wherein: The plane of the noise reduction baffles is perpendicular to the axial direction of the exhaust pipe body.
4. The binder jet additive manufactured exhaust pipe of claim 2, wherein: The outer wall is provided with a heat dissipation structure in the circumferential direction.
5. The binder jet additive manufactured exhaust pipe of claim 1, wherein: The inner wall further comprises two connecting ends, which are located at the two ends of the pipe body composed of the minimal surface structure and are respectively connected with an air inlet or an air outlet.
6. The binder jet additive manufactured exhaust pipe of claim 2, wherein: The noise reduction baffles are integrally formed with the inner wall and are prepared by a binder jet additive manufacturing technology.
7. The binder jet additive manufactured exhaust pipe of claim 2, wherein: At least one of the minimal surface structure units of the pipe body and the minimal surface structure units of the noise reduction baffles adopts the following model equation: ； l is the size of the minimal surface structure unit.
8. The binder jet additive manufactured exhaust pipe of claim 2, wherein: At least one of the minimal surface structure units of the pipe body and the minimal surface structure units of the noise reduction baffles adopts the following model equation: ； l is the size of the minimal surface structure unit.
9. The binder jet additive manufactured exhaust pipe of claim 2, wherein: The minimal surface structure units of the pipe body and the minimal surface structure units of the noise reduction baffles adopt the following model equation: ； ； l is the size of the minimal surface structure unit.
10. The binder jet additive manufactured exhaust pipe of claim 2, wherein: The porosity of the inner wall decreases in the direction of the flow of the gas, or / and the porosity of the noise reduction baffles decreases.