Cavity structure core box based on ship four-stroke engine

Abstract

The invention relates to a cavity structure core box based on a ship four-stroke engine, and belongs to the technical field of ship large-cylinder-diameter medium-speed four-stroke engines. The air inlet valve seat ring and the exhaust valve seat ring are arranged at the bottom of the core box shell, the air valve mechanism penetrates through the core box shell and is matched with the air inlet valve seat ring and the exhaust valve seat ring, and the air inlet channel and the exhaust channel are arranged in the core box shell and are connected with the air inlet valve seat ring and the exhaust valve seat ring respectively. The top of the core box shell and the air valve mechanism are connected with an air valve spring pressing mechanism; a plurality of hollow cavities which are not communicated are formed in the core box shell, the hollow cavities are connected through reinforcing ribs, and preset distances are reserved between the hollow cavities and the air inlet channel and between the hollow cavities and the air outlet channel. By arranging the hollow cavity and the reinforcing rib structure, the weight is effectively reduced, and the structural stability is ensured; an integral processing structure is adopted, so that the assembly complexity is reduced; the air passage test of engines with different cylinder diameters is realized through a principle of similar structure and flow.

Description

Technical Field

[0001] The present invention belongs to the technical field of large-bore medium-speed four-stroke engines for ships, and particularly relates to a cavity structure core box based on a four-stroke engine for ships. Background Art

[0002] In the technical field of traditional medium-speed four-stroke engines for ships, the structures of the intake and exhaust ports have a decisive influence on the vortices of the internal air flow movement and the distribution of the in-cylinder mixture near the top dead center, thus affecting the entire combustion and power stroke of the medium-speed four-stroke engine. Therefore, organizing good gas flow in the air passage has a very positive effect on optimizing the uniformity of the in-cylinder mixture and promoting flame diffusion combustion.

[0003] In order to verify the design level of the engine air passage structure and accurately evaluate the flow capacity of the air passage product, the traditional method usually manufactures an integral integrated structure air passage core box based on the air passage design model. By machining structures such as air passages, valve seats, air valves, and valve seats in a whole piece of metal or resin material, the shape of the air passage area inside the actual engine is simulated. And it is loaded onto the air passage steady flow blowing test bench, and the flow performance of the air passage is tested through a special blowing test. However, in the technical field of large-bore medium-speed four-stroke engines for ships, due to the very large overall size of general engines, if the traditional complete integrated air passage core box is still used for test and measurement, the weight of the actually processed sample parts is often too large. This makes it very difficult in the hoisting and handling, position adjustment, and inspection of the overall airtightness of the core box during the test operation process. In addition, due to the structural characteristics of the integrated air passage core box itself, the material-related costs are often greatly increased. Therefore, the traditional integral integrated structure is not perfectly applicable to the field of air passage testing for medium-speed four-stroke engines for ships. Summary of the Invention

[0004] The object of the present invention is to provide a cavity structure core box based on a four-stroke engine for ships, which is specifically applicable to the air passage testing of large-bore medium-speed four-stroke engines for ships.

[0005] To achieve the above object, the technical solution of the present invention provides a cavity structure core box based on a marine four-stroke engine, including a core box housing, an intake valve seat ring and an exhaust valve seat ring provided at the bottom of the core box housing, a valve mechanism passing through the core box housing and cooperating with the intake valve seat ring and the exhaust valve seat ring, and an intake passage and an exhaust passage provided inside the core box housing and respectively connected to the intake valve seat ring and the exhaust valve seat ring; a valve spring pressing mechanism is connected between the top of the core box housing and the valve mechanism; a plurality of non-connected hollow cavities are provided inside the core box housing, and the hollow cavities are connected by reinforcing ribs, and a preset distance is reserved between the hollow cavities and the intake passage and the exhaust passage.

[0006] Preferably, the hollow cavity is a completely hollow structure, and its quantity and layout are adapted to the size and weight requirements of the core box housing.

[0007] Preferably, the thickness and distribution of the reinforcing ribs are adapted to the load-bearing requirements of the core box housing to prevent structural deformation caused by the hollow cavities.

[0008] Preferably, the valve mechanism includes a valve guide and a valve; the valve guide is fixed in the core box housing by interference fit, the valve passes through the valve guide, one end of which is a flared valve head, which is sealingly matched with the intake valve seat ring or the exhaust valve seat ring, and the other end is connected to the valve spring pressing mechanism.

[0009] Preferably, the valve spring pressing mechanism includes a lock clip, a valve spring seat and a valve spring; the valve spring seat is fixed to the top of the valve by the lock clip, the valve spring is sleeved outside the valve, and both ends respectively abut against the valve spring seat and the top of the core box housing to press the valve against the intake valve seat ring or the exhaust valve seat ring and ensure sealing.

[0010] Preferably, the valve spring is a helical spring, the outer diameter of which matches the inner diameter of the valve spring seat, and the inner diameter matches the outer diameter of the valve to achieve stable force transmission.

[0011] Preferably, mounting positioning holes for mounting the intake valve seat ring and the exhaust valve seat ring are provided at the bottom of the core box housing.

[0012] Preferably, the intake valve seat ring and the exhaust valve seat ring are installed in the positioning holes at the bottom of the core box housing by interference fit, the inner surface is smooth and is precisely matched with the valve head of the valve to form a sealing interface.

[0013] Preferably, both the intake passage and the exhaust passage are bent pipe structures, and their shapes are adapted to the intake and exhaust flow characteristics of the engine to guide the air flow to generate eddy currents and reduce flow resistance.

[0014] Preferably, the core box housing is integrally machined by cutting or integrally formed by 3D printing, and the exhaust passage, the intake passage, the intake valve seat ring, the exhaust valve seat ring, and the hollow cavity structure are directly formed in the blank material.

[0015] In summary, the present invention includes the following beneficial technical effects:

[0016] The core box of the present invention is provided with a plurality of hollow cavity structures inside, which effectively reduces the weight of the core box sample and greatly facilitates the hoisting operation during the test. At the same time, the uniquely designed rib structure provides strong support for the overall framework of the core box housing, effectively avoiding the problem of self-weight deformation caused by the hollow structure, and ensuring the airtightness and structural stability of the core box.

[0017] The present invention adopts an integral processing structure, and is integrally printed and formed during the manufacturing process, minimizing the complex assembly of unnecessary components and improving the convenience of manufacturing and processing. On the basis of ensuring that the flow characteristics of the engine airway are not changed, the airtightness of the core box is ensured reliably with as few assembly structures as possible.

[0018] The present invention belongs to the technical field of large-bore medium-speed four-stroke marine engines, and is mainly applied to a steady-flow blowing special test bench. Through the principle of structural and flow similarity, the core box housing, the intake valve seat ring, the exhaust valve seat ring, the valve mechanism, the valve spring pressing mechanism, etc. can be scaled down or up to the existing core box size, realizing the steady-flow blowing test of four-stroke engines with different cylinder bores, and having broad application prospects and practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of a core box with a cavity structure based on a marine four-stroke engine according to the present invention;

[0020] Figure 2 It is a cross-sectional view of the intake passage in a core box with a cavity structure based on a marine four-stroke engine according to the present invention;

[0021] Figure 3 It is a cross-sectional view of the exhaust passage in a core box with a cavity structure based on a marine four-stroke engine according to the present invention;

[0022] Figure 4 It is a schematic diagram of the valve mechanism in a core box with a cavity structure based on a marine four-stroke engine according to the present invention;

[0023] Figure 5 It is a schematic diagram of the valve spring pressing mechanism in a core box with a cavity structure based on a marine four-stroke engine according to the present invention.

[0024] Reference numerals: 1. core box housing; 2. intake valve seat ring; 3. exhaust valve seat ring; 4. hollow cavity; 5. exhaust passage; 6. intake passage; 7. valve mechanism; 8. valve spring compression mechanism; 9. valve guide; 10. valve; 11. lock clip; 12. valve spring seat; 13. valve spring. Detailed implementation manners

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] The embodiment of the present invention discloses a core box with a cavity structure based on a marine four-stroke engine, which is specifically applicable to the air passage test of a marine medium-speed four-stroke engine with a large cylinder diameter. Through optimized design, this core box effectively solves many problems of traditional integrated air passage core boxes in terms of weight, cost, and processing and manufacturing while ensuring the test accuracy.

[0027] Based on the air passage structure of a marine four-stroke engine with a large cylinder diameter, the present invention is machined to form shapes such as air passages and valve seats on a complete blank material, or directly manufactured by 3D printing. And the core box is internally provided with a plurality of hollow cavity 4 structures, which can effectively reduce the overall weight of the core box. At the same time, a reinforcing rib structure is provided between the plurality of hollow cavities 4, which can avoid the problem of self-weight deformation of the core box due to the internal hollow cavity 4. Therefore, the core box with the hollow cavity 4 structure provided by the present invention can ensure the overall airtightness while effectively reducing its own weight, reducing material-related costs, and shortening the processing and manufacturing cycle.

[0028] The core box of the present invention mainly includes a core box housing 1, an intake valve seat ring 2, an exhaust valve seat ring 3, a hollow cavity 4, an exhaust passage 5, an intake passage 6, a valve mechanism 7, and a valve spring compression mechanism 8. The core box housing 1 serves as the main framework, and its shape is designed based on a marine medium-speed four-stroke engine. It internally contains a plurality of hollow cavities 4, which are completely hollow structures and are not directly connected to each other, but are connected to each other through reinforcing ribs to support the housing and avoid self-weight deformation. The upper and lower surfaces of the housing are provided with installation and positioning holes for the valve spring 13, the intake valve seat ring 2, and the exhaust valve seat ring 3, providing an installation foundation and positioning holes for the intake valve seat ring 2, the exhaust valve seat ring 3, the valve mechanism 7, the valve spring compression mechanism 8, etc., simulating the shape of the engine air passage area, providing a basic structure for the air passage test, and at the same time reducing its own weight and material cost through the design of the hollow cavity 4.

[0029] Both the intake valve seat ring 2 and the exhaust valve seat ring 3 are installed in the positioning holes at the bottom of the core box housing 1 by interference fit, respectively close to the side where the intake passage 6 is located and the side where the exhaust passage 5 is located. The intake valve seat ring 2 is of annular structure with a smooth inner surface, which closely cooperates with the bottom surface of the valve 10 to ensure sealing, provides a sealing interface for the intake process, prevents gas leakage, and ensures the intake efficiency; the exhaust valve seat ring 3 has a similar structure and is adjusted according to the design of the bottom of the valve 10, provides a sealing interface for the exhaust process, and ensures the exhaust efficiency.

[0030] The intake passage 6 and the exhaust passage 5 are located inside the core box housing 1, connecting the intake valve seat ring 2 with the intake inlet of the core box and the exhaust valve seat ring 3 with the exhaust outlet of the core box respectively. The intake passage 6 is a bent pipe structure, designed to guide fresh air or mixture into the cylinder. Its shape and size are optimized according to the intake flow characteristics of the engine to generate good swirl and mixture distribution, simulate the engine intake passage 6, provide a passage for the intake process, optimize the air flow movement, improve the uniformity of the mixture in the cylinder, promote flame diffusion combustion, and enhance the combustion efficiency of the engine; the exhaust passage 5 guides the exhaust gas out, is a bent pipe structure, and its shape and size are optimized according to the exhaust flow characteristics of the engine to reduce the flow resistance and improve the exhaust efficiency, simulate the engine exhaust passage 5, provide a passage for the exhaust process, ensure the smooth discharge of the exhaust gas, reduce the exhaust back pressure, and improve the engine performance.

[0031] The valve mechanism 7 mainly consists of a valve guide 9 and a valve 10, passing through the core box housing 1. The valve guide 9 is of tubular structure with a smooth inner surface for the valve 10 to pass through, and is installed in the core box housing 1 by interference fit, providing accurate guidance for the valve 10 to ensure that the valve 10 can move up and down accurately, achieve sealing cooperation with the seat ring, and ensure the sealing of the cylinder. The valve 10 is of long rod-like structure, passing through the valve guide 9 and extending to the intake valve seat ring 2 or the exhaust valve seat ring 3. One end is a valve head for sealing cooperation with the intake valve seat ring 2 or the exhaust valve seat ring 3, and the other end is connected to the valve spring pressing mechanism 8 to control the intake and exhaust processes of the cylinder. The gas enters and exits through the opening and closing of the valve 10 to ensure the normal working cycle of the engine. Among them, the valve head is of flared shape with a smooth surface, and the contact surface with the intake valve seat ring 2 or the exhaust valve seat ring 3 is precision machined to ensure good sealing effect.

[0032] The valve spring pressing mechanism 8 is located at the top of the core box housing 1 and is connected to the valve mechanism 7. It mainly includes a lock clip 11, a valve spring seat 12, and a valve spring 13. The lock clip 11 is in a ring-shaped or clamping structure and is used to connect the valve 10 and the valve spring seat 12; the valve spring seat 12 is in a disc-shaped or ring-shaped structure with a through hole in the middle, and is fixed to the top of the valve 10 through the lock clip 11. The valve spring seat 12 provides support for the valve spring 13; the valve spring 13 is in a helical spring structure, having a certain elasticity and strength. It is sleeved outside the top of the valve 10 and is installed between the valve spring seat 12 and the top of the core box housing 1. Its outer diameter matches the inner diameter of the valve spring seat 12, and its inner diameter matches the outer diameter of the valve 10 to ensure good installation and force transmission; the valve spring 13 presses the valve head of the valve 10 against the intake valve seat ring 2 or the exhaust valve seat ring 3 through the spring force, ensuring that the surface of the valve 10 is closely attached to the surface of the intake valve seat ring 2 or the exhaust valve seat ring 3, effectively ensuring the airtightness of the core box and preventing gas leakage. At the same time, the valve spring 13 can also absorb the impact force during the movement of the valve 10, protecting the valve 10 and the seat ring from damage.

[0033] The core box with a cavity structure described in the present invention contains multiple hollow cavity 4 structures inside (the hollow cavity 4 structure must maintain a certain distance from the exhaust passage 5 and the intake passage 6), which can effectively reduce the weight of the core box sample, providing great convenience for the requirements of test and lifting operations. At the same time, its uniquely designed rib structure can effectively support the overall framework of the core box housing 1, avoiding the problem of self-weight deformation of the core box caused by the hollow structure, and ensuring the airtightness and structural stability of the core box.

[0034] During the manufacturing process, the core box adopts an integral processing structure. The airway, valve seat and other shapes can be machined by cutting on a complete blank material, or directly manufactured and processed integrally by 3D printing, minimizing the complex assembly of unnecessary components, providing convenience for the manufacturing process, effectively reducing the material-related costs, and shortening the manufacturing cycle. And, on the basis of not changing the flow characteristics of the engine airway, ensuring the reliability of the airtightness of the core box with as few assembly structures as possible.

[0035] In addition, the core box of the present invention belongs to the technical field of marine large-bore medium-speed four-stroke engines and is mainly applied to the steady-flow blowing special test bench. According to the principle of structural and flow similarity, the core box housing 1, the intake valve seat ring 2, the exhaust valve seat ring 3, the valve mechanism 7, the valve spring pressing mechanism 8, etc. can be scaled down or up to the existing core box size to realize the steady-flow blowing test of four-stroke engines with different cylinder bores, having broad application prospects and practical value.

[0036] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A cavity structure core box based on a four-stroke ship engine, characterized in that: The invention comprises a core box shell (1), an intake valve seat ring (2) and an exhaust valve seat ring (3) arranged at the bottom of the core box shell (1), a valve mechanism (7) penetrating the core box shell (1) and cooperating with the intake valve seat ring (2) and the exhaust valve seat ring (3), and an intake passage (6) and an exhaust passage (5) arranged inside the core box shell (1) and respectively connected to the intake valve seat ring (2) and the exhaust valve seat ring (3); a valve spring pressing mechanism (8) is connected to the valve mechanism (7) at the top of the core box shell (1); a plurality of non-connected hollow cavities (4) are arranged inside the core box shell (1), each of the hollow cavities (4) is connected by a reinforcing rib, and a preset distance is retained between the hollow cavity (4) and the intake passage (6) and the exhaust passage (5).

2. A cavity structure core box based on a marine four-stroke engine according to claim 1, characterized in that: The hollow cavities (4) are completely hollow structures, and the number and layout of the hollow cavities (4) are adapted to the size and weight requirements of the core box shell (1).

3. A cavity structure core box based on a marine four-stroke engine according to claim 2, characterized in that: The thickness and distribution of the reinforcing ribs are adapted to the load-bearing requirements of the core box shell (1) and are used to prevent structural deformation caused by the hollow cavity (4).

4. A cavity structure core box based on a marine four-stroke engine according to claim 3, characterized in that: The valve mechanism (7) comprises a valve guide (9) and a valve (10); the valve guide (9) is fixed in the core box shell (1) by interference fit, and the valve (10) is inserted into the valve guide (9), one end of which is a flared valve head that is sealed with the intake valve seat ring (2) or the exhaust valve seat ring (3), and the other end is connected to the valve spring clamping mechanism (8).

5. A cavity structure core box based on a marine four-stroke engine according to claim 4, characterized in that: The valve spring pressing mechanism (8) comprises a locking clamp (11), a valve spring seat (12) and a valve spring (13); the valve spring seat (12) is fixed to the top of the air valve (10) by the locking clamp (11); the valve spring (13) is sleeved on the outside of the air valve (10), with two ends respectively abutting against the valve spring seat (12) and the top of the core box shell (1), so as to press the air valve (10) against the intake valve seat ring (2) or the exhaust valve seat ring (3) and ensure sealing.

6. A cavity structure core box based on a marine four-stroke engine according to claim 5, characterized in that: The valve spring (13) is a spiral spring, the outer diameter of which matches the inner diameter of the valve spring seat (12), and the inner diameter of which matches the outer diameter of the valve (10), so as to achieve stable force transmission.

7. A cavity structure core box based on a marine four-stroke engine according to any one of claims 1 to 6, characterized in that: The bottom of the core box shell (1) is provided with mounting positioning holes for mounting the intake valve seat ring (2) and the exhaust valve seat ring (3).

8. A cavity structure core box based on a marine four-stroke engine according to claim 7, characterized in that: The intake valve seat ring (2) and the exhaust valve seat ring (3) are installed in the positioning holes at the bottom of the core box shell (1) through interference fit, and the inner surfaces are smooth and precisely matched with the valve head of the gas valve (10) to form a sealing interface.

9. A cavity structure core box based on a marine four-stroke engine according to any one of claims 1 to 6, characterized in that: The air inlet (6) and the exhaust (5) are both curved pipe structures, the shapes of which are adapted to the air inlet and exhaust flow characteristics of the engine, and are used to guide the airflow to generate vortices and reduce flow resistance.

10. A cavity structure core box based on a marine four-stroke engine according to any one of claims 1 to 6, characterized in that: The core box shell (1) is integrally formed by integral cutting or 3D printing, and the exhaust duct (5), the intake duct (6), the intake valve seat ring (2), the exhaust valve seat ring (3) and the hollow cavity (4) structure are directly formed in the blank material.

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