An engine combustion chamber oil leakage structure

Abstract

The utility model discloses an engine combustion chamber oil leakage structure, include: mounting seat, fixed base, valve, steel ball, spring and standard adjustment pad, fixed base upper end seal installation in the shell outside, and the lower end detachable seal connection mounting seat upper end, mounting seat and fixed base inside through and jointly formed have installation cavity, and the installation cavity upper and lower respectively communicate shell and mounting seat outside to form the oil leakage passage, valve, steel ball, spring and the number adjustable standard adjustment pad are in the installation cavity and are in contact with each other setting gradually, and through valve and steel ball along the installation cavity axis up and down movement is opened or sealed to the oil leakage passage both ends respectively, realizes in the engine start initial period or parking automatic opening to discharge residual oil, closes seal when the engine normal work guarantees not to leak the air and makes the engine normal work. And through adjusting the number of standard adjustment pad, adjust spring initial telescopic amount to change the combustion chamber oil leakage passage closing pressure, and reach higher accuracy requirement.

Description

Technical Field

[0001] This utility model relates to the field of aero-engine technology, specifically to an oil draining structure for an engine combustion chamber. Background Technology

[0002] During the low-temperature start-up process at high altitudes, micro-engines often experience either a rich fuel start-up or a failed start, leading to fuel accumulation in the combustion chamber. If this accumulated fuel is not drained promptly, it may detonate in the combustion chamber upon restarting, resulting in a large flame at the exhaust nozzle. This can compromise the engine's safe operation. The combustion chamber fuel drain structure needs to automatically open during initial engine start-up or when the engine is stopped to drain residual fuel from the bottom of the combustion chamber casing, and then close and seal during normal engine operation to ensure no leakage and allow the engine to function properly.

[0003] Existing fuel drain structures for aero-engine combustion chambers use the spring force value resulting from the depth of screw insertion to adjust the shut-off pressure range. This depends on the machining results of the parts, and the shut-off pressure accuracy is not high, with a large fluctuation range. In addition, the sealing surfaces of existing fuel drain structures for aero-engine combustion chambers are mostly direct surface seals between metal surfaces, which have high requirements for the axis of the two surfaces during movement, resulting in reduced sealing performance of the mating surfaces. Utility Model Content

[0004] To address the problems existing in the prior art, the purpose of this utility model is to provide an engine combustion chamber oil drain structure that is simple in structure, easy to disassemble, has good sealing performance, high adjustment accuracy, and low cost. It uses a standard adjusting shim to adjust the initial compression of the spring, thereby adjusting the pressure required for the steel ball sealing surface and the mounting seat sealing surface to seal. Ultimately, it ensures that the oil drain structure can open and seal within the specified pressure difference range, reducing the impact of combustion chamber oil accumulation on the engine.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] An engine combustion chamber oil drain structure includes: a mounting base, a fixed base, a valve, a steel ball, a spring, and a standard adjusting shim. The upper end of the fixed base is sealed and installed outside the housing, and the lower end is detachably and sealed to the upper end of the mounting base. The mounting base and the fixed base are internally connected and together form a mounting cavity. The upper and lower parts of the mounting cavity are respectively connected to the inside of the housing and the outside of the mounting base to form an oil drain channel. The valve, steel ball, spring, and a number of adjustable standard adjusting shims are sequentially arranged in contact with each other in the mounting cavity. The valve and the steel ball move up and down along the axis of the mounting cavity to open or seal the two ends of the oil drain channel respectively.

[0007] As a further improvement, the two ends of the valve are limited by the housing and the mounting base, respectively.

[0008] As a further improvement, the upper end of the valve is formed with a boss that matches the oil unloading through hole provided on the housing. The upper end of the boss extends into the housing through the oil unloading through hole, and the lower end of the boss extends out of the housing, so that the movement position of the valve and the housing is restricted.

[0009] As a further improvement, the valve is provided with an oil drain hole to connect the inside and outside of the valve cavity.

[0010] As a further improvement, there are gaps between the outer side of the valve and the inner side of the fixed seat, as well as between the inner side of the valve and the outer side of the steel ball.

[0011] As a further improvement, one end of the spring is ground flat to ensure that its axis is always parallel to the axis of the valve during assembly or operation.

[0012] As a further improvement, the mounting base has an intermediate step for mounting a steel ball, a spring, and a standard adjusting pad. A conical surface is provided at the intermediate step. When the airflow pushes the valve and causes the steel ball to squeeze the spring, the spherical surface of the steel ball contacts the conical surface to form a line seal. When the pressure is insufficient and the steel ball is dislodged from the mounting base under the action of the spring, the oil drain channel opens and the accumulated oil is discharged from the lower end of the mounting base.

[0013] As a further improvement, an oil drain pipe is installed at the lower end of the mounting base to drain accumulated oil.

[0014] As a further improvement, the drain pipe is welded to the mounting base;

[0015] And / or the housing is welded to the mounting base.

[0016] As a further improvement, the mounting base is threadedly connected to the fixing base, and a sealing gasket is provided at the connection.

[0017] The beneficial effects of this utility model are:

[0018] (1) When the engine of this utility model is working normally, the air pressure in the combustion chamber is greater than the external atmospheric pressure. The pressure difference between the inside and outside causes the spring to compress downward, and the steel ball surface contacts the conical surface of the mounting seat to form a line seal. The structure is simple and the sealing effect is good. At the same time, a large proportion of the core components are standard parts that are easy to purchase on the market, so as to achieve low cost. It can also prevent air leakage in the combustion chamber and ensure the normal operation of the engine. During the engine's dummy start or just after starting, the pressure in the combustion chamber is insufficient. The steel ball is disengaged from the mounting seat under the action of the spring, and the oil drain channel is in the open state. The accumulated oil is discharged from the oil drain pipe. The conical surface of the mounting seat contacts the spherical surface of the steel ball to form a line contact, thereby closing the oil drain channel and preventing air leakage.

[0019] (2) The combustion chamber oil drain structure of this utility model can change the closing pressure of the combustion chamber oil drain channel by adjusting the number of standard adjusting pads and adjusting the initial extension of the spring, thereby adjusting the pressure required for sealing between the steel ball sealing surface and the mounting seat sealing surface, and finally ensuring that the oil drain structure can be opened and sealed within the specified pressure difference range, reducing the impact of combustion chamber oil accumulation on the engine, and achieving high precision requirements. Attached Figure Description

[0020] Figure 1 This is a cross-sectional schematic diagram of an engine combustion chamber oil drain structure according to the present invention;

[0021] Figure 2 This is a cross-sectional schematic diagram of the fixing base of this utility model;

[0022] Figure 3 This is a cross-sectional schematic diagram of the valve of this utility model;

[0023] Figure 4 This is a cross-sectional schematic diagram of the mounting base of this utility model.

[0024] Reference numerals: 1-Mounting base; 11-Conical surface; 2-Sealing gasket; 3-Fixed base; 4-Valve; 41-Boss; 42-Drain hole; 5-Housing; 6-Steel ball; 7-Spring; 8-Standard adjusting shim; 9-Drain pipe. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0026] In one embodiment, such as Figure 1-4 As shown, an engine combustion chamber oil drain structure comprises a mounting base 1, a sealing gasket 2, a fixing base 3, a valve 4, a housing 5, a steel ball 6, a spring 7, a standard adjusting shim 8, and an oil drain pipe 9. An oil drain hole is formed on the housing 5. The oil drain hole of the housing 5 is welded to one end of the fixing base 3 or sealed by other means. The other end of the fixing base 3 is sealed to one end of the mounting base 1. An installation cavity is formed inside the mounting base 1 and the fixing base 3, communicating with the oil drain hole. The upper and lower parts of the installation cavity are connected to the inside of the housing 5 and the outside of the mounting base 1, respectively, to form an oil drain channel. The valve 4 and the steel ball 6, as well as the spring 7 and the adjustable standard adjusting shims 8, are disposed within the installation cavity. The valve 4 and the steel ball 6 move up and down along the axis of the installation cavity to open or seal both ends of the oil drain channel.

[0027] The valve 4 is limited at both ends by the housing 5 and the mounting base 1, respectively. Specifically, the valve 4 is installed near the housing 5 and located in the cavity of the fixed base 3, and is limited by the mounting base 1. It can move up and down along the axis of the fixed base 3, i.e., the axis of the mounting cavity. Preferably, one end of the valve 4 is designed with a boss that matches the oil discharge hole. The upper end of the boss extends into the housing 5, and the lower end of the boss extends out of the housing 5, so that the valve 4 and the housing 5 are restricted in their movement position. The steel ball 6 is installed at the end away from the housing 5 and located in the cavity of the mounting base 1. The spring 7 and the standard adjusting shim 8 are set in the cavity of the mounting base 1. One end of the spring 7 contacts the steel ball 6, and the other end contacts the standard adjusting shim 8. The end of the mounting base 1 away from the steel ball 6 is connected to the oil drain pipe 9. Preferably, the oil drain pipe 9 is welded to the mounting base 1.

[0028] The valve 4 is designed with an oil drain hole 42 to connect the inside and outside of the valve 4 cavity; there are gaps between the outer side of the valve 4 and the inner side of the fixed seat 3, and between the inner side of the valve 4 and the outer side of the steel ball 6, so that the oil accumulated in the combustion chamber cavity can enter the oil drain channel through the oil discharge hole and then be discharged through the oil drain pipe 9.

[0029] Preferably, one end of the mounting base 1 is provided with an external thread, and a sealing gasket 2 is provided on the outer limit sleeve of the mounting base 1. When the external thread is connected with the internal thread of the fixed base 3, both ends of the sealing gasket 2 are in contact with the mounting base 1 and the fixed base 3 respectively to achieve sealing.

[0030] Further optimization involves using brass for the mounting base 1 and copper for the sealing gasket 2. A low-stiffness spring is used.

[0031] Furthermore, both the mounting base 1 and the fixing base 3 are provided with annular fuse mounting holes for installing fuses to prevent loosening and avoid the nuts from coming loose during operation, which could cause excess material to affect operation.

[0032] Specifically, such as Figure 2 As shown, the mounting base 3 is cylindrical, with one end having an arc-shaped cut surface that fits against the surface of the housing 5 for easy welding, and is used to connect to the combustion chamber; as Figure 3As shown, a boss 41 is provided at one end of the valve 4. The upper end of the boss 41 extends into the housing 5, and the lower end of the boss 41 extends out of the housing. The valve 4 is installed in the fixed seat 3 and moves up and down along the axis of the valve 4 within the fixed seat 3 to limit the movement distance between the valve and the housing. Oil drain holes 42 are symmetrically provided on the left and right sides at the lower end of the valve 4. A steel ball 6 is installed in the cavity of the valve 4. The inner diameter of the valve 4 cavity is slightly larger than the diameter of the steel ball 6 so that the gap between the oil drain hole, the steel ball 6 and the mounting seat 1 is connected, thereby ensuring a smooth oil drain channel. This allows the oil accumulated in the combustion chamber to flow into the space between the fixed seat 3 and the valve 4 through the gap between the housing 5 and the valve 4, and then enter the valve 4 and the mounting seat 1 through the oil drain hole 42. Finally, the steel ball 6 moves upward, allowing the oil accumulated in the combustion chamber to be discharged from the oil drain pipe 9. One end of spring 7 is ground flat to ensure that its axis is always parallel to the axis of valve 4 during assembly or operation; one end of spring 7 contacts steel ball 6, and the other end contacts standard adjusting pad 8, with spring 7 providing elastic support for steel ball 6 and valve 4; Figure 4 As shown, the mounting base 1 has an intermediate step for mounting the steel ball 6, spring 7 and standard adjusting pad 8. A conical surface 11 is provided at the intermediate step of the mounting base 1. When the engine is working normally, the airflow pushes the valve 4 and the steel ball 6. The steel ball 6 compresses the spring 7, and the spherical surface of the steel ball 6 contacts the conical surface of the mounting base 1 to form a line seal. When the engine starts, if the pressure is insufficient, the steel ball 6 will disengage from the mounting base 1 under the action of the spring, and the oil drain channel will open. The accumulated oil generated will be discharged from the oil drain pipe 9.

[0033] Because the pressure inside the combustion chamber of a micro-engine is relatively low during operation, the pressure value and range for opening or closing the oil drain channel are also small. There are slight differences in the performance of different batches of engines. At this time, it is necessary to adjust the initial force value of the selected low stiffness spring according to the test results. This can be achieved by simply unscrewing the mounting base 1 and the fixed base 3, removing the valve 4, steel ball 6, and spring 7, adding or subtracting the number of standard adjusting shims 8, and then reinstalling them in their original positions. The operation process is simple and can effectively meet the oil drain and sealing requirements of different engines.

[0034] When the engine is operating normally, the air pressure inside the combustion chamber is greater than the external atmospheric pressure. The pressure difference between the inside and outside causes the spring to compress downwards, and the steel ball surface contacts the conical surface of the mounting base, forming a line seal to prevent air leakage from the combustion chamber and ensure normal engine operation. During engine start-up or initial start-up, the pressure inside the combustion chamber is insufficient. The steel ball is released from the mounting base under the action of the spring, and the oil drain channel is open, allowing the accumulated oil to be discharged from the oil drain pipe. The conical surface of the mounting base contacts the spherical surface of the steel ball, forming a line contact to close the oil drain channel and prevent air leakage.

[0035] Compared to existing fuel drain structures for aero-engine combustion chambers, which change the closing pressure range by altering the spring force through screw thread engagement—a process dependent on component manufacturing and exhibiting low precision and significant fluctuation—this novel fuel drain structure allows for adjustment of the initial spring extension and retraction by adjusting the number of standard adjusting shims, thereby changing the closing pressure of the fuel drain channel and achieving higher precision. Furthermore, 55% of the core components in this structure are readily available standard parts such as gaskets, steel balls, springs, standard adjusting shims, and drain pipes, resulting in a significant cost advantage compared to other fuel drain structures.

[0036] The above embodiments merely illustrate specific implementations of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model.

Claims

1. An engine combustion chamber oil drain structure, characterized in that, include: The mounting base, fixed base, valve, steel ball, spring, and standard adjusting shims are arranged in sequence. The upper end of the fixed base is sealed and installed outside the housing, and the lower end is detachably sealed and connected to the upper end of the mounting base. The mounting base and the fixed base are internally connected and together form a mounting cavity. The upper and lower parts of the mounting cavity are connected to the inside of the housing and the outside of the mounting base to form an oil drain channel. The valve, steel ball, spring, and standard adjusting shims of adjustable quantity are arranged in sequence in contact with each other in the mounting cavity. The valve and steel ball move up and down along the axis of the mounting cavity to open or seal the two ends of the oil drain channel respectively.

2. The engine combustion chamber oil drain structure according to claim 1, characterized in that, The valve is limited at both ends by the housing and the mounting base, respectively.

3. The engine combustion chamber oil drain structure according to claim 2, characterized in that, The upper end of the valve has a boss that matches the oil unloading hole provided on the housing. The upper end of the boss extends into the housing through the oil unloading hole, and the lower end of the boss extends out of the housing, thereby restricting the movement position between the valve and the housing.

4. The engine combustion chamber oil drain structure according to claim 3, characterized in that, The valve has an oil drain hole to connect the inside and outside of the valve cavity.

5. The engine combustion chamber oil drain structure according to claim 4, characterized in that, There are gaps between the outer side of the valve and the inner side of the fixed seat, as well as between the inner side of the valve and the outer side of the steel ball.

6. The engine combustion chamber oil drain structure according to claim 1, characterized in that, One end of the spring is ground flat to ensure that its axis is always parallel to the axis of the valve during assembly or operation.

7. The engine combustion chamber oil drain structure according to claim 1, characterized in that, The mounting base has an intermediate step for mounting a steel ball, a spring, and a standard adjusting pad. A conical surface is provided at the intermediate step. When the airflow pushes the valve and causes the steel ball to squeeze the spring, the spherical surface of the steel ball contacts the conical surface to form a line seal. When the pressure is insufficient, the steel ball disengages from the mounting base under the action of the spring, and the oil drain channel opens at the lower end, causing the accumulated oil to be discharged from the lower end of the mounting base.

8. The engine combustion chamber oil drain structure according to claim 7, characterized in that, An oil drain pipe is installed at the lower end of the mounting base so that accumulated oil can be discharged through the oil drain pipe.

9. The engine combustion chamber oil drain structure according to claim 8, characterized in that, The drain pipe is welded to the mounting base; And / or the housing is welded to the mounting base.

10. An engine combustion chamber oil draining structure according to any one of claims 1-9, characterized in that, The mounting base and the fixed base are threaded together, and a sealing gasket is provided at the connection.

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