Large marine diesel engine cylinder sleeve inner hole sleeve core type circulating water cooling tool and method

Abstract

The large marine diesel engine cylinder sleeve inner hole sleeve core type circulating water cooling tool comprises a circulating water cooling pipe, the bottom end of the circulating water cooling pipe is sealed through a bottom plate, an inner water supply pipe is fixed to the inner wall of the circulating water cooling pipe, and the top end of the inner water supply pipe extends out of the circulating water cooling pipe and is bent to form a water inlet pipe; the bottom end of the inner water supply pipe is arranged at the inner bottom of the circulating water cooling pipe and bent to form an arc-shaped water outlet pipe, a water outlet is machined in the upper portion of the circulating water cooling pipe, and a water outlet pipe is fixed to the position of the water outlet. The heat of the inner hole of the cylinder sleeve in a casting state is continuously taken away by circulating water in a circulating water cooling manner, and the inner hole is continuously radiated and cooled, so that the aim of continuously increasing the cooling speed of the inner hole of the cylinder sleeve is fulfilled, the fine structure of the inner hole of the cylinder sleeve and the high strength of the inner surface are ensured, and the wear resistance of the working surface of the inner hole of the cylinder sleeve is finally improved; in addition, operation is simple and efficient, and the cooling speed of the diesel engine cylinder sleeve inner hole in the casting state can be continuously increased.

Description

Technical Field

[0001] The invention relates to the technical field of marine diesel engine cylinder liner casting, and mainly relates to a core-shell type circulating water cooling tool and method for an inner hole of a large marine diesel engine cylinder liner. Background Art

[0002] The cylinder liner of a marine low-speed diesel engine is usually made of gray cast iron alloy material. Its inner hole surface and its running piston form a complete set of friction pairs. Since the inner surface of the cylinder liner is in direct contact with combustion and explosion and the working environment is harsh, high requirements are placed on the wear resistance and strength of the inner hole surface of the cylinder liner, especially the inner hole surface of the cylinder liner is required to have high strength and fine structure.

[0003] In order to meet the special requirements of the inner hole of the cylinder liner, when casting the cylinder liner blank, it is key to speed up the cooling speed of the inner hole of the cylinder liner in the cast state. Generally, the process of attaching a chill iron to the surface of the inner hole of the cylinder liner is adopted to speed up the cooling speed. However, on the one hand, attaching the chill iron is entirely manual operation, which is labor-intensive; on the other hand, the heat storage capacity of the chill iron is limited, and it is easy to saturate and cannot continuously accelerate the cooling, especially for thick-walled cylinder liners. Although spray cooling has an obvious cooling effect, the reaction is too intense and it is easy to cause stress. Heat treatment is required to relieve stress in the later stage. At the same time, each type of cylinder liner must first simulate and calculate its solidification time, and then remove the core tube, and finally implement the spray cooling plan. There is a lot of preliminary preparation work and the operation is not very convenient. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a core-type circulating water cooling tooling and method for the inner hole of the cylinder liner of a large marine diesel engine. This tooling is through a core tube tooling with circulating water in the cylinder liner core tube, and the circulating water cooling method is used to allow the circulating water to continuously take away the heat of the inner hole of the cylinder liner in the cast state, so that the inner hole can continuously dissipate heat and cool, so as to achieve the purpose of continuously accelerating the cooling rate of the inner hole of the cylinder liner, thereby ensuring the fine structure of the inner hole of the cylinder liner and the high strength of the inner surface, and finally improving the wear resistance of the working surface of the inner hole of the cylinder liner; in addition, the operation is simple and efficient, and the cooling rate of the inner hole of the diesel engine cylinder liner in the cast state can be continuously accelerated.

[0005] In order to achieve the above-mentioned technical features, the purpose of the present invention is achieved as follows: a large-scale marine diesel engine cylinder liner inner hole sleeve core type circulating water cooling tooling includes a circulating water cooling pipe, the bottom end of the circulating water cooling pipe is closed by a bottom plate, an inner water supply pipe is fixed on the inner wall of the circulating water cooling pipe, the top end of the inner water supply pipe extends out of the circulating water cooling pipe and is bent to form a water inlet pipe, the bottom end of the inner water supply pipe is arranged at the inner bottom of the circulating water cooling pipe and is bent to form an arc-shaped water outlet pipe, the upper part of the circulating water cooling pipe is processed with a water outlet, and the water outlet pipe is fixed at the position of the water outlet.

[0006] Preferably, the circulating water cooling pipe is made of a seamless steel pipe, and a waist-shaped hole for hoisting is provided on the upper part of the circulating water cooling pipe.

[0007] Preferably, the bottom plate is sealed and welded to the bottom end of the circulating water cooling pipe via a bottom plate welding point.

[0008] Preferably, the inner water supply pipe is fixed to the inner wall of the circulating water cooling pipe by welding through a first welding point and a second welding point.

[0009] Preferably, the water outlet of the arc-shaped water outlet pipe faces the top end of the circulating water cooling pipe.

[0010] Preferably, the water inlet pipe is connected to a water tower and introduces cold water, and the water outlet pipe is connected to a water tower or a bathhouse water tank.

[0011] Preferably, the entire circulating water cooling pipe is arranged in the central part of the cylinder liner core tube, core tube molding sand is arranged on the outer wall of the cylinder liner core tube, the core tube molding sand is in contact with the inner hole of the cast cylinder liner, the outer wall of the cast cylinder liner is in contact with the cylinder liner molding sand, and the cylinder liner molding sand is arranged inside the cylinder liner casting sand box.

[0012] Preferably, an external chiller is provided between the middle outer wall of the cast cylinder liner and the cylinder liner molding sand.

[0013] On the other hand, the present invention provides a casting method for the inner hole sleeve core type circulating water cooling of the cylinder liner of a large marine diesel engine, the casting method is implemented by using the sleeve core type circulating water cooling tooling, and comprises the following steps: Step 1, bending and forming of the inner water supply pipe: Select steel pipes of appropriate sizes and bend the ends to form water inlet pipes and arc-shaped water outlet pipes respectively; Step 2, assembly of the internal water supply pipe: Select a circulating water cooling pipe of appropriate size and fix the bent inner water supply pipe inside the circulating water cooling pipe by spot welding; Step 3, bottom sealing of circulating water cooling pipe: After the internal water supply pipe is fixed, weld the bottom plate at the bottom end of the circulating water cooling pipe for sealing; Step 4: Installation of the core-type circulating water cooling tooling: After the casting of the as-cast cylinder liner is completed, the core-type circulating water cooling tooling is placed inside the cylinder liner core tube by hoisting the core as a whole and keeping the coaxial arrangement; Step 5: Connection of core-type circulating water cooling tooling: Connect the water inlet pipe to the cold water pipe of the water tower, introduce cold water, and the cold water is discharged from the arc-shaped outlet pipe and flows into the circulating water cooling pipe. The water level inside the circulating water cooling pipe rises to the outlet pipe position and flows out from the outlet pipe. The outlet pipe is connected to the cooling water tower and the bathhouse water tank. The hot water is used for employees to take a bath. Step 6, cyclic cooling of the cast cylinder liner: As the cast cylinder liner solidifies and cools down from liquid to solid, a large amount of heat is transferred to the cylinder liner core tube through the core tube molding sand and the cylinder liner molding sand, causing the cylinder liner core tube to heat up rapidly, and even become red and reach saturation. As the heat radiation in the cylinder liner core tube continues to intensify, the water inside the circulating water cooling tube is heated. Due to the flow of circulating water, the heat is continuously taken away from the outlet pipe in the form of hot water, thereby realizing a positive temperature gradient of heat conduction from the cast cylinder liner to the circulating water, continuously taking away the heat of the entire inner hole of the cast cylinder liner, thereby accelerating the cooling of the inner hole of the cast cylinder liner, and realizing continuous cooling of the inner hole surface of the cylinder liner, thereby ensuring the inner hole strength and tissue density, and further improving the wear resistance of the inner surface of the cylinder liner; Step 7, disassembly of the core-type circulating water cooling tooling: After the casting of the as-cast cylinder liner is completed, take out the circulating water cooling pipe for next use.

[0014] By adopting circulating water cooling to accelerate cooling, the stress of the inner hole of the cylinder liner is reduced, and no subsequent stress relief heat treatment is required. According to metallographic inspection, the inner hole structure of the cylinder liner has been significantly refined, the strength has been increased by 20~40Mpa, and the inner hole surface hardness has been increased by 30~40HB.

[0015] The present invention has the following beneficial effects: 1. By adopting the present invention, the circulating water can continuously take away the heat of the inner hole of the cylinder liner in the cast state, so that the inner hole always dissipates heat first, so as to achieve the purpose of continuously accelerating the cooling speed of the inner hole of the cylinder liner, thereby ensuring the fine structure of the inner hole of the cylinder liner and the high strength of the inner surface, thereby improving the wear resistance of the surface of the inner hole of the cylinder liner. At the same time, the hot water is led to the bathhouse water tower, which can be used for the casting employees to take a bath, and partial heat energy recovery can be achieved.

[0016] 2. By adopting the present invention, in the production process of a certain type of heavy-walled low-speed diesel engine cylinder liner casting, the above-mentioned inner bore circulating water cooling method is adopted, which not only greatly reduces the actual labor intensity of workers, but also makes the inner bore of the cylinder liner in the cast state continuously and acceleratedly cooled, and the inner bore stress of the cylinder liner is minimized, and no later stress relief heat treatment is required. According to metallographic detection, the inner bore structure of the cylinder liner has been significantly refined, the strength has been increased by 20~40Mpa, and the inner bore surface hardness has been increased by 30~40HB, which improves the mechanical properties and inner bore surface wear resistance of the cylinder liner of the marine low-speed diesel engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0018] Figure 1 It is a tooling structure diagram of the present invention.

[0019] Figure 2 For the present invention Figure 1 An enlarged view of the water inlet pipe.

[0020] Figure 3 For the present invention Figure 1 An enlarged view of the location of the middle arc outlet pipe.

[0021] Figure 4 This is a diagram of the installation layout of the casting process tooling of the present invention.

[0022] In the figure: water inlet pipe 1, first welding point 2, inner water supply pipe 3, waist-shaped hole 4, water outlet 5, water outlet pipe 6, circulating water cooling pipe 7, second welding point 8, arc-shaped water outlet pipe 9, bottom plate 10, bottom plate welding point 11, inner hole surface of cast cylinder liner 12, cylinder liner casting sand box 13, core tube molding sand 14, cylinder liner molding sand 15, external chiller 16, cast cylinder liner 17. DETAILED DESCRIPTION

[0023] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0024] Embodiment 1: See also Figure 1-4 A large marine diesel engine cylinder liner inner hole sleeve core type circulating water cooling tooling includes a circulating water cooling pipe 7, the bottom end of the circulating water cooling pipe 7 is closed by a bottom plate 10, an inner water supply pipe 3 is fixed on the inner wall of the circulating water cooling pipe 7, the top end of the inner water supply pipe 3 extends out of the circulating water cooling pipe 7 and forms a water inlet pipe 1 by bending, the bottom end of the inner water supply pipe 3 is arranged at the inner bottom of the circulating water cooling pipe 7 and forms an arc-shaped water outlet pipe 9 by bending, and a water outlet 5 is processed on the upper part of the circulating water cooling pipe 7, and a water outlet pipe 6 is fixed at the position of the water outlet 5. This tooling installs another core tube tooling with circulating water inside the cylinder liner core tube, and uses circulating water cooling to allow the circulating water to continuously take away the heat from the inner hole of the cylinder liner in the cast state, allowing the inner hole to continuously dissipate heat and cool, thereby achieving the purpose of continuously accelerating the cooling rate of the inner hole of the cylinder liner, thereby ensuring the fine structure of the inner hole of the cylinder liner and the high strength of the inner surface, and ultimately improving the wear resistance of the working surface of the inner hole of the cylinder liner; in addition, the operation is simple and efficient, and can continuously accelerate the cooling rate of the inner hole of the diesel engine cylinder liner in the cast state.

[0025] Furthermore, the circulating water cooling pipe 7 is made of seamless steel pipe, and a waist-shaped hole 4 for hoisting is provided on the upper part of the circulating water cooling pipe 7. By adopting seamless steel pipe, the subsequent leakage problem is effectively prevented. By adopting the waist-shaped hole 4, it is convenient to hoist and lower the entire circulating water cooling pipe 7 by hoisting, thereby facilitating the installation and arrangement of the entire tooling.

[0026] Furthermore, the bottom plate 10 is sealed and welded to the bottom end of the circulating water cooling pipe 7 via the bottom plate welding point 11. The bottom plate 10 can be used to reliably seal the circulating water cooling pipe 7.

[0027] Furthermore, the inner water supply pipe 3 is welded and fixed to the inner wall of the circulating water cooling pipe 7 through the first welding point 2 and the second welding point 8. The first welding point 2 and the second welding point 8 can be used to reliably fix the inner water supply pipe 3.

[0028] Furthermore, the water outlet of the arc-shaped water outlet pipe 9 faces the top of the circulating water cooling pipe 7. The arc-shaped water outlet pipe 9 can be used to guide the cold water entering the circulating water cooling pipe 7, thereby ensuring that the cold water is continuously sprayed upward.

[0029] Furthermore, the water inlet pipe 1 is connected to a water tower and introduces cold water, and the water outlet pipe 6 is connected to a water tower or a bathhouse water reservoir. The heated water can be easily led out through the water outlet pipe 6, thereby achieving the effect of heat energy reuse.

[0030] Furthermore, the entire circulating water cooling pipe 7 is arranged at the center of the cylinder liner core tube 18, and the outer wall of the cylinder liner core tube 18 is provided with core tube molding sand 14, which contacts the inner hole of the cast cylinder liner 17, and the outer wall of the cast cylinder liner 17 contacts the cylinder liner molding sand 15, and the cylinder liner molding sand 15 is arranged inside the cylinder liner casting sand box 13. Through the above casting structure, the inner cylinder liner can be effectively cast.

[0031] Furthermore, an external chiller 16 is provided between the middle outer wall of the as-cast cylinder liner 17 and the cylinder liner molding sand 15. The external chiller 16 can be used to realize external cooling of the as-cast cylinder liner 17 during the casting process.

[0032] Embodiment 2: The present invention provides a casting method for a large marine diesel engine cylinder liner inner hole sleeve core-type circulating water cooling, the casting method is implemented by using the sleeve core-type circulating water cooling tooling, and comprises the following steps: Step 1, bending and forming of the inner water supply pipe 3: Select steel pipes of appropriate sizes and bend the ends to form a water inlet pipe 1 and an arc-shaped water outlet pipe 9; Step 2, assembly of the inner water supply pipe 3: Select a circulating water cooling pipe 7 of appropriate size, and fix the bent inner water supply pipe 3 to the inside of the circulating water cooling pipe 7 by spot welding; Step 3, sealing the bottom of the circulating water cooling tube 7: After the internal water supply pipe 3 is fixed, a bottom plate 10 is welded to the bottom end of the circulating water cooling pipe 7 for sealing; Step 4: Installation of the core-type circulating water cooling tooling: After the casting of the as-cast cylinder liner 17 is completed, the core-in-shell circulating water cooling tooling is sheathed inside the cylinder liner core tube 18 by an integral hoisting and lowering core method, and the coaxial arrangement is maintained; Step 5: Connection of core-type circulating water cooling tooling: Connect the water inlet pipe 1 to the cold water pipe of the water tower, introduce cold water, the cold water is discharged from the arc-shaped water outlet pipe 9, and flows into the circulating water cooling pipe 7. The water level inside the circulating water cooling pipe 7 rises to the position of the water outlet pipe 6, and flows out from the water outlet pipe 6. The water outlet pipe 6 is connected to the cooling water tower and the bathhouse water tank, and the hot water is used for employees to take a bath; Step 6, cyclic cooling of the cast cylinder liner 17: As the cast cylinder liner 17 solidifies and cools down from liquid to solid, a large amount of heat is conducted to the cylinder liner core tube 18 through the core tube sand 14 and the cylinder liner sand 15, causing the cylinder liner core tube 18 to heat up rapidly until it turns red and reaches saturation. As the heat radiation in the cylinder liner core tube 18 continues to intensify, the water inside the circulating water cooling tube 7 is heated. Due to the flow of circulating water, the heat is continuously taken away from the outlet pipe 6 in the form of hot water, thereby realizing a heat conduction positive temperature gradient from the cast cylinder liner 17 to the circulating water, continuously taking away the heat of the entire inner hole of the cast cylinder liner 17, thereby accelerating the cooling of the inner hole of the cast cylinder liner 17, and realizing continuous cooling of the inner hole surface of the cylinder liner, thereby ensuring the inner hole strength and tissue density, and further improving the wear resistance of the inner surface of the cylinder liner; Step 7, disassembly of the core-type circulating water cooling tooling: After the casting of the as-cast cylinder liner 17 is completed, the circulating water cooling pipe 7 is taken out for next use.

[0033] Furthermore, by adopting circulating water cooling to accelerate cooling, the stress of the inner hole of the cylinder liner is reduced, and no subsequent stress relief heat treatment is required. After metallographic inspection, the inner hole structure of the cylinder liner has been significantly refined, the strength has been increased by 20~40Mpa, and the inner hole surface hardness has been increased by 30~40HB.

Claims

1. A large marine diesel engine cylinder liner inner hole sleeve core type circulating water cooling tooling, characterized in that: The invention comprises a circulating water cooling pipe (7), the bottom end of which is sealed by a bottom plate (10), an inner water supply pipe (3) is fixed on the inner wall of the circulating water cooling pipe (7), the top end of the inner water supply pipe (3) extends out of the circulating water cooling pipe (7) and is bent to form a water inlet pipe (1), the bottom end of the inner water supply pipe (3) is arranged at the inner bottom of the circulating water cooling pipe (7) and is bent to form an arc-shaped water outlet pipe (9), and a water outlet (5) is processed on the upper part of the circulating water cooling pipe (7), and a water outlet pipe (6) is fixed at the position of the water outlet (5).

2. According to claim 1, the large marine diesel engine cylinder liner inner hole sleeve core type circulating water cooling tooling is characterized by: The circulating water cooling pipe (7) is made of a seamless steel pipe, and a waist-shaped hole (4) for hoisting is provided on the upper part of the circulating water cooling pipe (7).

3. According to claim 1, the large marine diesel engine cylinder liner inner hole sleeve core type circulating water cooling tooling is characterized by: The bottom plate (10) is sealed and welded to the bottom end of the circulating water cooling pipe (7) via a bottom plate welding point (11).

4. According to claim 3, the large marine diesel engine cylinder liner inner hole sleeve core type circulating water cooling tooling is characterized in that: The inner water supply pipe (3) is welded and fixed to the inner side wall of the circulating water cooling pipe (7) via a first welding point (2) and a second welding point (8).

5. According to claim 1, the large marine diesel engine cylinder liner inner hole sleeve core type circulating water cooling tooling is characterized by: The water outlet of the arc-shaped water outlet pipe (9) faces the top end of the circulating water cooling pipe (7).

6. According to claim 1, the large marine diesel engine cylinder liner inner hole sleeve core type circulating water cooling tooling is characterized by: The water inlet pipe (1) is connected to a water tower and introduces cold water, and the water outlet pipe (6) is connected to a water tower or a bathhouse water reservoir.

7. According to claim 1, the large marine diesel engine cylinder liner inner hole sleeve core type circulating water cooling tooling is characterized by: The entire circulating water cooling pipe (7) is arranged at the center of the cylinder liner core tube (18), and core tube molding sand (14) is arranged on the outer wall of the cylinder liner core tube (18). The core tube molding sand (14) is in contact with the inner hole of the cast cylinder liner (17), and the outer wall of the cast cylinder liner (17) is in contact with the cylinder liner molding sand (15). The cylinder liner molding sand (15) is arranged inside the cylinder liner casting sand box (13).

8. According to claim 1, the large marine diesel engine cylinder liner inner hole sleeve core type circulating water cooling tooling is characterized by: An external chiller (16) is provided between the middle outer wall of the cast cylinder liner (17) and the cylinder liner molding sand (15).

9. A casting method for inner hole core type circulating water cooling of a large marine diesel engine cylinder liner, characterized in that: The casting method is implemented by using the sleeve-core circulating water cooling tooling according to any one of claims 1 to 8, comprising the following steps: Step 1: Bending and forming the inner water supply pipe (3): Select steel pipes of suitable size and bend the ends to form a water inlet pipe (1) and an arc-shaped water outlet pipe (9); Step 2, assembly of the inner water supply pipe (3): Select a circulating water cooling pipe (7) of suitable size, and fix the bent inner water supply pipe (3) inside the circulating water cooling pipe (7) by spot welding; Step 3, sealing the bottom of the circulating water cooling tube (7): After the internal water supply pipe (3) is fixed, a bottom plate (10) is welded to the bottom end of the circulating water cooling pipe (7) for sealing; Step 4: Installation of the core-type circulating water cooling tooling: After the casting of the as-cast cylinder liner (17) is completed, the core-in-shell circulating water cooling tooling is sheathed inside the cylinder liner core tube (18) by an integral hoisting and lowering core method, and the coaxial arrangement is maintained; Step 5: Connection of core-type circulating water cooling tooling: The water inlet pipe (1) is connected to the cold water pipe of the water tower to introduce cold water, and the cold water is discharged from the arc-shaped water outlet pipe (9) and flows into the circulating water cooling pipe (7). The water level inside the circulating water cooling pipe (7) rises to the position of the water outlet pipe (6) and flows out from the water outlet pipe (6). The water outlet pipe (6) is connected to the cooling water tower and the water storage tank of the bathhouse, and the hot water is used for employees to take a bath. Step 6, cyclic cooling of the cast cylinder liner (17): As the cast cylinder liner (17) solidifies and cools from liquid to solid, a large amount of heat is transferred to the cylinder liner core tube (18) through the core tube molding sand (14) and the cylinder liner molding sand (15), causing the cylinder liner core tube (18) to heat up rapidly until it becomes red and reaches saturation. As the heat radiation in the cylinder liner core tube (18) continues to intensify, the water inside the circulating water cooling tube (7) is heated. Due to the flow of the circulating water, the heat is continuously taken away from the outlet pipe (6) in the form of hot water, thereby achieving a positive temperature gradient of heat conduction from the cast cylinder liner (17) to the circulating water, continuously taking away the heat of the entire inner hole of the cast cylinder liner (17), thereby accelerating the cooling of the inner hole of the cast cylinder liner (17) and achieving continuous cooling of the inner hole surface of the cylinder liner, thereby ensuring the inner hole strength and structural density, and further improving the wear resistance of the inner surface of the cylinder liner; Step 7, disassembly of the core-type circulating water cooling tooling: After the casting of the as-cast cylinder liner (17) is completed, the circulating water cooling pipe (7) is taken out for next use.

10. The casting method of large marine diesel engine cylinder liner inner hole sleeve core type circulating water cooling according to claim 9, characterized in that: By adopting circulating water cooling to accelerate cooling, the stress of the inner hole of the cylinder liner is reduced, and no subsequent stress relief heat treatment is required. According to metallographic inspection, the inner hole structure of the cylinder liner has been significantly refined, the strength has been increased by 20~40Mpa, and the inner hole surface hardness has been increased by 30~40HB.

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