Fuel injection control system of low-speed diesel engine

Abstract

The invention relates to the technical field of diesel engines, in particular to a fuel injection control system of a low-speed diesel engine, which comprises an outer cylinder fixed on a cylinder cover of the diesel engine and a fuel rail positioned in the outer cylinder, and a plurality of fuel injection nozzles distributed at equal intervals are arranged below the fuel rail. A metal corrugated pipe for connecting the oil nozzle and the bottom branch pipe of the fuel rail is arranged between the oil nozzle and the bottom branch pipe; the oil nozzle is inserted into the combustion chamber through the cylinder cover; a plurality of thermosensitive mounting sleeves which are distributed at equal intervals are arranged on the fuel rail in a sleeving manner; a plurality of first damping assemblies which are uniformly distributed along the circumference and are used for reducing vibration of the fuel rail are arranged between the thermosensitive mounting sleeves and the outer cylinder; and an elastic fixing assembly is arranged between the oil nozzle and the cylinder cover. According to the control system, the thermosensitive installation sleeve and the first damping assembly are installed between the fuel rail and the outer cylinder to isolate and attenuate vibration, the stability and reliability of the fuel rail are improved, the precision and stability of fuel injection control are greatly improved, and therefore the overall performance of the low-speed diesel engine is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of diesel engines, and in particular relates to a fuel injection control system for a low-speed diesel engine. Background Art

[0002] In a high-vibration environment such as ships, the fuel rail and fuel injector of the low-speed diesel engine fuel injection control system will produce certain vibrations during operation. Excessive vibration will affect the accuracy of fuel injection control and the injection effect. The vibration of the fuel rail and fuel injector comes from many aspects. For example, the high-pressure oil pump will produce pressure fluctuations during the fuel supply process. These fluctuations will be transmitted to the fuel rail, thereby causing the vibration of the fuel rail. For example, the fuel injector will produce pressure fluctuations when injecting fuel, especially when the injection interval and injection amount change. The fluctuations will be transmitted to the fuel rail, causing its vibration. For example, the engine will produce vibrations during operation, and the vibrations will be transmitted to the fuel rail and fuel injector through the connectors and supporting structures, causing vibrations.

[0003] The existing low-speed diesel engine fuel injection control system is difficult to meet the needs of different application scenarios, and often considers the needs of land or general industrial environments more. However, when facing the special environment of ships, many inadaptability may be exposed. During navigation, ships will be affected by various natural forces such as waves and tides, resulting in large vibrations and shocks. However, the fuel rails and injectors of the existing low-speed diesel engine fuel injection control system have certain deficiencies in anti-vibration design, and are difficult to withstand continuous vibration and shock, which leads to loosening of components, increased wear, and even damage, which not only affects the accuracy and stability of fuel injection, but may also cause more serious failures; at the same time, the existing low-speed diesel engine fuel injection control system's anti-vibration measures are also relatively simple, generally only using a single vibration isolation element to reduce vibration, and the anti-vibration effect is not ideal, making it difficult to cope with complex marine environments.

[0004] To this end, we provide a low-speed diesel engine fuel injection control system to solve the above-mentioned problems. Summary of the invention

[0005] The purpose of the present invention is to provide a low-speed diesel engine fuel injection control system in view of the problems of the background technology.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0007] A low-speed diesel engine fuel injection control system comprises an outer cylinder fixed on a diesel engine cylinder head and a fuel rail located inside the outer cylinder, a plurality of fuel injection nozzles distributed at equal intervals are arranged below the fuel rail, a metal bellows is arranged between the fuel injection nozzle and a bottom branch pipe of the fuel rail for connecting the two, and the fuel injection nozzle is inserted into a combustion chamber through the cylinder head.

[0008] The fuel rail is provided with a plurality of equally spaced thermal mounting sleeves, and a plurality of first damping components evenly distributed along the circumference for reducing vibration of the fuel rail are provided between the thermal mounting sleeve and the outer cylinder; an elastic fixing component is provided between the fuel injector and the cylinder head, and three second damping components evenly distributed along the circumference for reducing vibration of the fuel injector are provided on the upper and lower end surfaces of the fuel injector.

[0009] As a further optimization scheme of the present invention, the outer cylinder includes two semi-cylindrical bodies fixedly spliced ​​with each other, and the bottom of the semi-cylindrical body is provided with an L-shaped mounting plate for mounting on the cylinder head; an air inlet hole is provided on one end face of the semi-cylindrical body, and a cooling fan is provided on the other end face; and a movable door panel for mounting a first damping assembly is provided on the surface of the semi-cylindrical body.

[0010] As a further optimization solution of the present invention, a sound-absorbing layer is provided on the inner surface of the semi-cylindrical body.

[0011] As a further optimization scheme of the present invention, the thermal mounting sleeve includes a thermal ring body located in the fuel rail groove and a mounting ring body with a fixed sleeve arranged outside the thermal ring body; a heating ring body and a cooling ring body for adjusting the temperature of the thermal ring body are respectively arranged on both sides of the mounting ring body.

[0012] As a further optimization scheme of the present invention, the first damping assembly includes a damper and a first ball joint and a second ball joint located at both ends of the damper; the first ball joint is fixedly mounted on the surface of the mounting ring body, the second ball joint is fixedly mounted on the inner wall of the outer tube, and a spring is provided between the first ball joint and the housing of the damper.

[0013] As a further optimization scheme of the present invention, the elastic fixing assembly includes an outer elastic ring body and an inner elastic ring body located in the stepped hole of the cylinder head, and a pressure plate is provided on the top of the inner elastic ring body, and the pressure plate is fixedly installed on the cylinder head.

[0014] As a further optimization solution of the present invention, the contact surfaces of the outer elastic ring body and the inner elastic ring body are set to be matching inclined surfaces, and the inner surface of the inner elastic ring body abuts against the fuel injection nozzle.

[0015] As a further optimization scheme of the present invention, the structure of the second damping assembly is the same as that of the first damping assembly; the outer end of the second damping assembly on the lower end surface of the injector is fixedly connected to the pressure plate, and the outer end of the second damping assembly on the upper end surface of the injector is fixedly connected to the outer surface of the outer cylinder.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present invention installs a vibration isolation element between the fuel rail and the outer cylinder to isolate and attenuate vibration by arranging a thermal mounting sleeve and a first damping assembly, thereby preventing the fuel rail from being directly mounted on the cylinder head to cause excessive vibration. In addition, an anti-vibration measure combining a thermal sensitive material with a damping mechanism is adopted. The thermal sensitive material expands or contracts with temperature changes, thereby offsetting or alleviating the vibration of the fuel rail to a certain extent. The damping mechanism further consumes vibration energy, thereby improving the stability and reliability of the fuel rail, reducing failures and damages caused by vibration, and greatly improving the accuracy and stability of fuel injection control, thereby improving the overall performance of the low-speed diesel engine.

[0018] 2. The present invention optimizes the flexible connection portion between the fuel injector and the cylinder head by providing a metal bellows, an elastic fixing component and a second damping component, and adopts vibration isolation treatment to reduce the vibration of the fuel injector caused by the cylinder head. At the same time, a plurality of second damping components that play a supporting role are provided at the upper and lower ends of the fuel injector to increase its stability and reduce vibration.

[0019] 3. The present invention can protect the fuel rail by providing an outer cylinder, prevent the fuel rail from being damaged by external impact or damage, enhance the structural stability of the entire fuel rail and the fuel injector system, and reduce looseness or deformation caused by vibration. The design of the outer cylinder makes the installation and replacement of the damping mechanism more convenient, and also facilitates the maintenance and inspection of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a three-dimensional schematic diagram of the overall structure of the present invention;

[0021] Figure 2 It is a schematic diagram of the connection structure between the fuel rail and the fuel injection nozzle of the present invention;

[0022] Figure 3 It is a schematic diagram of the structure of the thermal-sensitive mounting sleeve of the present invention;

[0023] Figure 4 It is a schematic structural diagram of the first damping component of the present invention;

[0024] Figure 5 It is a schematic diagram of the outer cylinder structure of the present invention;

[0025] Figure 6 It is a cross-sectional view of a semi-cylindrical body of the present invention;

[0026] Figure 7 It is a schematic diagram of the structure of the elastic fixing component of the present invention.

[0027] In the figure:

[0028] 1. Outer cylinder; 101. Semi-cylinder; 102. L-shaped mounting plate; 103. Movable door plate; 104. Air inlet; 105. Cooling fan; 106. Noise-absorbing layer; 2. Fuel rail; 3. Thermosensitive mounting sleeve; 301. Thermosensitive ring; 302. Mounting ring; 303. Heating ring; 304. Cooling ring; 4. First damping assembly; 401. Damper; 402. First ball joint; 403. Second ball joint; 404. Spring; 5. Metal bellows; 6. Fuel injector; 7. Elastic fixing assembly; 701. Outer elastic ring; 702. Inner elastic ring; 703. Pressure plate; 8. Second damping assembly; 9. Cylinder head. DETAILED DESCRIPTION

[0029] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0030] Embodiment 1

[0031] In order to solve the problem that the existing diesel engine fuel injection control system is difficult to adapt to the environment with large vibration such as ships, the vibration of the fuel rail is too large during operation, thus affecting the accuracy of fuel injection control, please refer to Figure 1-Figure 2 The present invention provides a low-speed diesel engine fuel injection control system, comprising an outer cylinder 1 fixed on a diesel engine cylinder head 9 and a fuel rail 2 located inside the outer cylinder 1, a plurality of fuel injection nozzles 6 distributed at equal intervals are arranged below the fuel rail 2, a metal bellows 5 for connecting the fuel injection nozzle 6 and the bottom branch pipe of the fuel rail 2 is arranged between the two, the metal bellows 5 can absorb and disperse vibration energy to a certain extent, thereby reducing the vibration between the fuel injection nozzle 6 and the fuel rail 2, the fuel injection nozzle 6 is inserted into the combustion chamber through the cylinder head 9, a plurality of thermal sensitive mounting sleeves 3 distributed at equal intervals are sleeved on the fuel rail 2, and a plurality of first damping components 4 for reducing the vibration of the fuel rail 2 and uniformly distributed along the circumference are arranged between the thermal sensitive mounting sleeve 3 and the outer cylinder 1. The thermosensitive mounting sleeve 3 and the first damping component 4 are matched, and the anti-vibration measure combining the thermosensitive material with the damping mechanism is adopted. The thermosensitive material expands or contracts with the temperature change, which offsets or alleviates the vibration of the fuel rail 2 to a certain extent. The damping mechanism further consumes the vibration energy, effectively reduces the vibration impact on the fuel rail 2 during the ship's driving, improves its ability to resist vibration and impact, greatly improves the accuracy and stability of fuel injection control, and thus improves the overall performance of the low-speed diesel engine.

[0032] like Figure 5-Figure 6As shown, the outer cylinder 1 includes two semi-cylindrical bodies 101 fixedly spliced ​​to each other, and an L-shaped mounting plate 102 for mounting on the cylinder head 9 is provided at the bottom of the semi-cylindrical body 101; an air inlet hole 104 is provided on one end surface of the semi-cylindrical body 101, and a cooling fan 105 is provided on the other end surface; a movable door plate 103 for mounting the first damping assembly 4 is provided on the surface of the semi-cylindrical body 101; a sound-absorbing layer 106 is provided on the inner surface of the semi-cylindrical body 101, and the sound-absorbing layer 106 can significantly reduce the noise level of the fuel rail 2 and reduce the propagation of noise. The outer cylinder 1 can protect the fuel rail 2 and prevent external impact or damage from causing damage to the fuel rail 2. At the same time, the outer cylinder 1 provides a foundation for installation and support for the thermal mounting sleeve 3 and the first damping component 4, so that the entire vibration reduction system can work stably and reduce looseness or deformation caused by vibration; the setting of the movable door plate 103 makes the installation and replacement of the damping mechanism more convenient, and also facilitates the maintenance and inspection of the entire system. When the system needs to be maintained, the movable door plate 103 at the corresponding part can be opened. The cooperation of the air inlet 104 and the cooling fan 105 allows the heat of the fuel rail 2 to be dissipated in time, thereby improving the stability of the fuel injection control system.

[0033] like Figure 4 As shown, the first damping assembly 4 includes a damper 401 and a first ball joint 402 and a second ball joint 403 located at both ends of the damper 401; the first ball joint 402 is fixedly mounted on the surface of the mounting ring 302, the second ball joint 403 is fixedly mounted on the inner wall of the outer tube 1, and a spring 404 is provided between the first ball joint 402 and the housing of the damper 401, and the spring 404 is provided to enhance the damping effect. The damper 401 converts vibration energy into other forms of energy and dissipates it, reducing the amplitude and duration of vibration, and further reducing the vibration of the fuel rail 2. At the same time, the existence of the damper 401 also enhances the stability of the entire structure, so that the fuel rail 2 can better maintain its original position and shape when subjected to external impact or vibration.

[0034] Embodiment 2

[0035] On the basis of the first embodiment, in order to alleviate the vibration of the fuel rail 2 caused by temperature changes, further improve the anti-vibration performance of the fuel rail 2, and thus improve the accuracy and injection effect of the fuel injection control system, as shown in FIG. Figure 3 As shown, the thermosensitive mounting sleeve 3 includes a thermosensitive coil 301 located in the groove of the fuel rail 2 and a mounting sleeve 302 fixedly mounted outside the thermosensitive coil 301; a heating coil 303 and a cooling coil 304 for adjusting the temperature of the thermosensitive coil 301 are respectively arranged on both sides of the mounting coil 302. The arrangement of the heating coil 303 and the cooling coil 304 enables the thermosensitive coil 301 to have an adjustable heating or cooling function.

[0036] By utilizing the thermal expansion and contraction characteristics of the thermosensitive material, the thermosensitive coil 301 can automatically adjust its size as the temperature changes, so as to compensate for the size change of the fuel rail 2 caused by the temperature change and reduce the vibration caused by the size mismatch. When the fuel rail 2 is heated, the thermosensitive coil 301 expands or contracts as the temperature changes, effectively absorbing the vibration energy, and offsetting or alleviating the vibration of the fuel rail 2 to a certain extent. At the same time, the thermosensitive coil 301 also plays the role of a traditional vibration reduction element and has a buffering function. When the fuel rail 2 is vibrated, the thermosensitive coil 301 can absorb part of the vibration energy and convert it into heat energy to dissipate it, thereby reducing the vibration amplitude.

[0037] Embodiment 3

[0038] On the basis of the first and second embodiments, in order to reduce the vibration between the fuel injection nozzle 6 and the cylinder head 9 and improve the anti-vibration effect of the fuel injection nozzle 6, as shown in FIG. Figure 1-Figure 2 , Figure 7 As shown, an elastic fixing component 7 is provided between the fuel injector 6 and the cylinder head 9, and three second damping components 8 for reducing the vibration of the fuel injector 6 are provided on the upper and lower end surfaces of the fuel injector 6 and are evenly distributed along the circumference.

[0039] The elastic fixing assembly 7 includes an outer elastic ring body 701 and an inner elastic ring body 702 located in the stepped hole of the cylinder head 9. A pressure plate 703 is provided on the top of the inner elastic ring body 702, and the pressure plate 703 is fixedly mounted on the cylinder head 9. The contact surfaces of the outer elastic ring body 701 and the inner elastic ring body 702 are set as matching inclined surfaces, and the inner surface of the inner elastic ring body 702 abuts against the fuel injector 6. The elastic fixing assembly 7 is installed between the fuel injector 6 and the cylinder head 9, and the outer elastic ring body 701 and the inner elastic ring body 702 with good vibration reduction performance are used to effectively absorb and disperse vibration energy. At the same time, the outer elastic ring body 701 and the inner elastic ring body 702 are squeezed by the pressure plate 703, and the inner elastic ring body 702 and the fuel injector 6 can be in close contact, thereby ensuring a close fit between the fuel injector 6 and the cylinder head 9.

[0040] The structure of the second damping assembly 8 is the same as that of the first damping assembly 4; the outer end of the second damping assembly 8 on the lower end surface of the fuel injector 6 is fixedly connected to the pressure plate 703, and the outer end of the second damping assembly 8 on the upper end surface of the fuel injector 6 is fixedly connected to the outer surface of the outer cylinder 1. A plurality of second damping assemblies 8 that play a supporting role are provided at both the upper and lower ends of the fuel injector 6 to increase its stability and reduce vibration, and the vibration energy of the fuel injector 6 can be absorbed and dissipated by the second damping assembly 8.

[0041] The above-mentioned embodiment only expresses one implementation mode of the present invention, and its description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A low-speed diesel engine fuel injection control system, comprising an outer cylinder (1) fixed to a diesel engine cylinder head (9) and a fuel rail (2) located inside the outer cylinder (1), characterized in that: A plurality of fuel injection nozzles (6) are arranged at equal intervals below the fuel rail (2); a metal bellows (5) is arranged between the fuel injection nozzle (6) and the bottom branch pipe of the fuel rail (2) for connecting the two; and the fuel injection nozzle (6) is inserted into the combustion chamber through the cylinder head (9); The fuel rail (2) is provided with a plurality of heat-sensitive mounting sleeves (3) which are distributed at equal intervals, and a plurality of first damping components (4) which are evenly distributed along the circumference and are used to reduce vibration of the fuel rail (2) are provided between the heat-sensitive mounting sleeve (3) and the outer cylinder (1); An elastic fixing component (7) is provided between the fuel injector (6) and the cylinder head (9), and three second damping components (8) evenly distributed along the circumference for reducing vibration of the fuel injector (6) are provided on the upper and lower end surfaces of the fuel injector (6).

2. A low-speed diesel engine fuel injection control system according to claim 1, characterized in that: The outer cylinder (1) comprises two semi-cylindrical bodies (101) fixedly connected to each other, and an L-shaped mounting plate (102) for mounting on a cylinder head (9) is provided at the bottom of the semi-cylindrical body (101); An air inlet hole (104) is provided on one end surface of the semi-cylindrical body (101), and a heat dissipation fan (105) is provided on the other end surface; A movable door plate (103) for mounting the first damping assembly (4) is provided on the surface of the semi-cylindrical body (101).

3. A low speed diesel engine fuel injection control system according to claim 2, characterized in that: A sound-absorbing layer (106) is provided on the inner surface of the semi-cylindrical body (101).

4. A low speed diesel engine fuel injection control system according to claim 1, characterized in that: The thermal installation sleeve (3) comprises a thermal ring body (301) located in the groove of the fuel rail (2) and a mounting ring body (302) fixedly mounted outside the thermal ring body (301); A heating ring (303) and a cooling ring (304) for adjusting the temperature of the thermosensitive ring (301) are respectively arranged on both sides of the installation ring (302).

5. A low-speed diesel engine fuel injection control system according to claim 4, characterized in that: The first damping assembly (4) comprises a damper (401) and a first ball joint (402) and a second ball joint (403) located at two ends of the damper (401); The first ball joint (402) is fixedly mounted on the surface of the mounting ring (302), the second ball joint (403) is fixedly mounted on the inner wall of the outer cylinder (1), and a spring (404) is provided between the first ball joint (402) and the housing of the damper (401).

6. A low-speed diesel engine fuel injection control system according to claim 5, characterized in that: The elastic fixing assembly (7) comprises an outer elastic ring body (701) and an inner elastic ring body (702) located in the stepped hole of the cylinder head (9); a pressing plate (703) is provided on the top of the inner elastic ring body (702); and the pressing plate (703) is fixedly mounted on the cylinder head (9).

7. A low-speed diesel engine fuel injection control system according to claim 6, characterized in that: The contact surfaces of the outer elastic ring body (701) and the inner elastic ring body (702) are arranged as matching inclined surfaces, and the inner surface of the inner elastic ring body (702) abuts against the fuel injection nozzle (6).

8. A low speed diesel engine fuel injection control system according to claim 6, characterized in that: The structure of the second damping component (8) is the same as that of the first damping component (4); The outer end of the second damping component (8) on the lower end surface of the fuel injection nozzle (6) is fixedly connected to the pressure plate (703), and the outer end of the second damping component (8) on the upper end surface of the fuel injection nozzle (6) is fixedly connected to the outer surface of the outer cylinder (1).

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