Marine fuel injection valve

Abstract

The marine fuel injection valve comprises a valve shell, a pressure adjusting screw, a spring, a tappet and a needle valve element, a control valve cavity, a needle valve cavity and an oil injection cavity are formed in the valve shell, a valve port is formed in the lower end of the needle valve cavity, the pressure adjusting screw is in threaded connection with the valve shell, the tappet is in sliding fit with the control valve cavity, and a control cavity is formed between the tappet and the control valve cavity; a sealing part is arranged on the needle valve element, the needle valve element is in sliding fit with the needle valve cavity, and a pressure storage cavity is formed between the needle valve element and the needle valve cavity; the upper end of the spring is upwards supported on the pressure adjusting screw, the lower end of the spring is downwards supported on the tappet, the lower end of the tappet is downwards supported on the needle valve element, and the sealing part is downwards supported on the valve port; a fuel oil channel used for conveying fuel oil to the pressure storage cavity and a control oil channel used for conveying control oil to the control cavity are arranged in the valve shell. The marine fuel injection valve is compatible with precise control and traditional control, has the advantage of being wide in application range, and can reduce the cost for upgrading a traditional host.

Description

Technical Field

[0001] The present invention relates to the technical field of valves, and more particularly to a marine fuel injection valve. Background Art

[0002] There are mainly two schemes for controlling fuel injection of existing marine low-speed engines, namely the traditional control scheme and the precise control scheme.

[0003] The traditional control scheme uses a traditional marine fuel injection valve. The needle valve of the traditional marine fuel injection valve only overcomes the spring force, opens for injection when reaching the opening pressure, and closes when below the injection pressure. It is difficult to precisely control the fuel injection volume, but it has the characteristic of low cost.

[0004] The precise control scheme is to control the opening and closing of the needle valve by control oil. The fuel injection volume is controllable, which can save fuel and reduce emissions to a certain extent, but the cost is relatively high.

[0005] With the increasingly strict domestic and international emission regulations and the requirements of shipowners for low fuel consumption of the main engine, the precise control scheme is becoming more and more popular. The marine fuel injection valve adopted by the precise control scheme is suitable for newly built main engines and is used in conjunction with the precise control system of newly built main engines. It can precisely control the fuel injection volume to achieve the high-efficiency operation of the main engine, thereby improving fuel efficiency and reducing emissions.

[0006] However, the existing marine fuel injection valves suitable for newly built main engines and the precise control scheme are expensive and have complex structures, and can only be applied to main engines with precise control systems.

[0007] At present, the main engines adopting the traditional control scheme still dominate the number of main engines. These main engines need to replace the marine fuel injection valves with precise control for subsequent upgrades. However, at present, traditional marine fuel injection valves are still needed for transition, and there is a problem of too high cost in upgrading from traditional marine fuel injection valves to marine fuel injection valves with precise control. Summary of the Invention

[0008] The object of the present invention is to provide a marine fuel injection valve to alleviate or eliminate at least one of the above problems.

[0009] A marine fuel injection valve described in the present invention comprises a valve housing, a pressure regulating screw, a spring, a push rod and a needle valve core, wherein the valve housing is provided with a control valve chamber, a needle valve chamber and an injection chamber which are connected in sequence from top to bottom, the valve housing is provided with an injection hole which is connected with the injection chamber, the lower end of the needle valve chamber is provided with a valve port, the pressure regulating screw is threadedly connected with the valve housing, the pressure regulating screw is used to adjust the compression amount of the spring, the push rod is slidably matched with the control valve chamber, a control chamber is provided between the push rod and the control valve chamber, a sealing portion is provided on the needle valve core, the needle valve core is slidably matched with the needle valve chamber, a pressure storage chamber is provided between the needle valve core and the needle valve chamber, and the pressure storage chamber is located on the upper side of the valve port; the upper end of the spring The valve body is upwardly supported on the pressure regulating screw, the lower end of the spring is downwardly supported on the push rod, the lower end of the push rod is downwardly supported on the needle valve core, and the sealing part is downwardly supported on the valve port, and the sealing part closes the valve port to separate the pressure accumulation chamber and the injection chamber; the valve housing is provided with a fuel oil channel for conveying fuel oil to the pressure accumulation chamber and a control oil channel for conveying control oil to the control chamber, when the oil pressure of the fuel oil in the pressure accumulation chamber meets the first condition, the fuel oil in the pressure accumulation chamber pushes the needle valve core to move upward, and the valve port is opened to connect the pressure accumulation chamber and the injection chamber; when the control oil in the control chamber meets the second condition, the control oil in the control chamber applies an upward thrust to the push rod.

[0010] Optionally, the control valve chamber includes a first hole section and a second hole section located at the lower side of the first hole section, the push rod includes a first push rod section slidingly matched with the first hole section and a second push rod section matched with the second hole section, the aperture of the first hole section is larger than the aperture of the second hole section, the outer diameter of the first push rod section is larger than the outer diameter of the second push rod section, and the step surface between the first push rod section and the second push rod section, the step surface between the first hole section and the second hole section, the hole wall of the first hole section and the outer peripheral surface of the second push rod section form the control chamber.

[0011] Optionally, the control valve chamber also includes a third hole section located on the upper side of the first hole section, and the spring is located in the third hole section; the control valve chamber also includes a fourth hole section located on the upper side of the third hole section, and the pressure-adjusting screw is threadedly engaged with the fourth hole section; the control valve chamber also includes a fifth hole section located on the upper side of the fourth hole section, and a sealing ring is arranged between the pressure-adjusting screw and the hole wall of the fifth hole section; the aperture of the third hole section is larger than the aperture of the first hole section.

[0012] Optionally, the tappet further includes a shoulder located above the first tappet segment, the shoulder protruding outward from the first tappet segment, and the lower end of the spring being supported on the shoulder; the tappet further includes a third tappet segment located above the shoulder, and a first limiting portion for defining the upper dead center of the stroke of the third tappet segment is provided at the lower end of the pressure regulating screw; a first groove for cooperating with the upper end portion of the third tappet segment is provided at the first limiting portion; a second groove is provided at the lower end of the tappet, and the upper end portion of the needle valve core is in cooperation with the second groove.

[0013] Optionally, the needle valve cavity includes a sixth hole segment and a seventh hole segment located below the sixth hole segment, the aperture of the seventh hole segment being larger than that of the sixth hole segment, the valve port being located at the lower end of the seventh hole segment, the needle valve core including a first needle valve core segment cooperating with the sixth hole segment and a second needle valve core segment located below the first needle valve core segment, the sealing portion being provided at the lower end of the second needle valve core segment, the outer diameter of the second needle valve core segment being smaller than that of the first needle valve core segment, and a pressure accumulation cavity being formed between the wall of the seventh hole segment and the needle valve core.

[0014] Optionally, the needle valve core further includes a third needle valve core segment located below the second needle valve core segment, and the third needle valve core segment extends into the fuel injection cavity; when the sealing portion closes the valve port, the third needle valve core segment closes the fuel injection hole; when the sealing portion opens the valve port, the third needle valve core segment opens the fuel injection hole.

[0015] Optionally, the needle valve core further includes a fourth needle valve core segment located above the first needle valve core segment, the outer diameter of the fourth needle valve core segment being smaller than that of the first needle valve core segment, and the upper end portion of the fourth needle valve core segment being used to support the lower end portion of the tappet; a second limiting portion for defining the upper dead center of the stroke of the step surface between the first needle valve core segment and the fourth needle valve core segment is provided in the valve housing.

[0016] Optionally, the valve housing includes a control valve housing, a needle valve housing, and a nozzle connected in sequence from top to bottom, the control valve cavity being provided in the control valve housing, the needle valve cavity being provided in the needle valve housing, and the fuel injection cavity being provided in the nozzle.

[0017] Optionally, a first locking cap fixedly connected to the control valve housing presses the needle valve housing upward against the control valve housing, and the needle valve housing and the control valve housing are sealingly connected.

[0018] Optionally, a second locking cap fixedly connected to the needle valve housing presses the nozzle upward against the needle valve housing, and the nozzle and the needle valve housing are sealingly connected.

[0019] The present invention provides a marine fuel injection valve that is compatible with precise control and traditional control. It can not only meet the usage requirements of traditional main engines but also those of main engines with precise control systems, featuring a wide range of applications and being able to reduce the cost of upgrading traditional main engines. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of the marine fuel injection valve described in some embodiments; Figure 2 It is one of the cross-sectional views of the marine fuel injection valve described in some embodiments; Figure 3 It is the second cross-sectional view of the marine fuel injection valve described in some embodiments.

[0021] In the figures, 1 - control valve housing, 2 - tappet, 3 - pressure regulating screw, 4 - needle valve housing, 5 - needle valve core, 6 - nozzle, 7 - accumulator chamber, 8 - control chamber, 9 - spring, 10 - first locking cap, 11 - second locking cap, 12 - sealing ring, 13 - locking nut, 14 - mounting bolt, 101 - fourth hole section, 102 - third hole section, 103 - first hole section, 104 - second hole section, 105 - fifth hole section, 106 - first fuel oil passage section, 107 - fuel oil inlet, 108 - control oil passage, 109 - control oil inlet, 201 - third tappet section, 202 - shoulder, 203 - first tappet section, 204 - second tappet section, 205 - second groove, 206 - first step surface, 301 - first groove, 401 - sixth hole section, 402 - seventh hole section, 403 - valve port, 404 - second fuel oil passage section, 501 - first needle valve core section, 502 - second needle valve core section, 503 - third needle valve core section, 504 - second step surface, 505 - sealing surface; 506 - fourth needle valve core section; 601 - injection chamber, 602 - injection hole. Detailed Embodiments

[0022] The following will illustrate the embodiments of the present invention with reference to the drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the protection scope of the present invention.

[0023] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and thus the drawings only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0024] like Figures 1 to 3 A marine fuel injection valve shown in the figure comprises a valve housing, a pressure regulating screw 3, a spring 9, a tappet 2 and a needle valve core 5. The valve housing is provided with a control valve chamber, a needle valve chamber and an injection chamber 601 which are connected in sequence from top to bottom. The valve housing is provided with an injection hole 602 which is connected with the injection chamber 601. The lower end of the needle valve chamber is provided with a valve port 403. The pressure regulating screw 3 is threadedly connected with the valve housing. The pressure regulating screw 3 is used to adjust the compression amount of the spring 9. The tappet 2 is slidably matched with the control valve chamber. A control chamber 8 is provided between the tappet 2 and the control valve chamber. A sealing portion 505 is provided on the needle valve core 5. The needle valve core 5 is slidably matched with the needle valve chamber. A pressure storage chamber 7 is provided between the needle valve core 5 and the needle valve chamber. The pressure storage chamber 7 is located on the upper side of the valve port 403. The upper end of the spring 9 is directed to the upper side of the valve port 403. The upper part is supported on the pressure regulating screw 3, the lower end of the spring 9 is downwardly supported on the push rod 2, the lower end of the push rod 2 is downwardly supported on the needle valve core 5, the sealing part 505 is downwardly supported on the valve port 403, the sealing part 505 closes the valve port 403 to separate the pressure accumulation chamber 7 and the injection chamber 601; the valve housing is provided with a fuel oil channel for conveying fuel oil to the pressure accumulation chamber 7 and a control oil channel 108 for conveying control oil to the control chamber 8. When the oil pressure of the fuel oil in the pressure accumulation chamber 7 meets the first condition, the fuel oil in the pressure accumulation chamber 7 pushes the needle valve core 5 to move upward, and the valve port 403 is opened to connect the pressure accumulation chamber 7 and the injection chamber 601; when the control oil in the control chamber 8 meets the second condition, the control oil in the control chamber 8 applies an upward thrust to the push rod 2.

[0025] By adopting the above technical solution, the marine fuel injection valve is compatible with precise control and traditional control, which can meet the use requirements of both traditional main engines and main engines with precise control systems. It has a wide range of applications and can reduce the cost of upgrading traditional main engines.

[0026] In specific implementation, the valve housing, pressure regulating screw 3, spring 9, tappet 2 and needle valve core 5 form a needle valve. The first condition means that the oil pressure of the fuel oil in the accumulator chamber 7 is greater than the opening pressure of the needle valve. More specifically, the first condition means that the oil pressure of the fuel oil in the accumulator chamber 7 is greater than a first threshold value. At this time, the upward thrust applied by the fuel oil in the accumulator chamber 7 to the needle valve core 5 is greater than the first combined force that the needle valve core 5 receives and acts downward in addition to this thrust. The first combined force is the resultant force of the force applied by the tappet 2 to the needle valve core 5, the gravity of the needle valve core 5, and the acting force between the needle valve core 5 and the valve housing. By rotating the pressure regulating screw 3 to adjust the spring force of the spring 9, and by adjusting the oil pressure of the control oil in the control chamber 8, the force applied by the tappet 2 to the needle valve core 5 can be adjusted, and thus the opening pressure of the needle valve can be adjusted. The second condition means that the oil pressure of the control oil in the control chamber 8 is greater than 0. At this time, the control oil in the control chamber 8 applies an upward thrust to the tappet 2.

[0027] As a specific example, the control valve chamber includes a first hole section 103 and a second hole section 104 located below the first hole section 103. The tappet 2 includes a first tappet section 203 that slidably cooperates with the first hole section 103 and a second tappet section 204 that cooperates with the second hole section 104. The aperture of the first hole section 103 is larger than that of the second hole section 104, the outer diameter of the first tappet section 203 is larger than that of the second tappet section 204, and a control chamber 8 is formed by enclosing the step surface between the first tappet section 203 and the second tappet section 204, the step surface between the first hole section 103 and the second hole section 104, and the outer peripheral surface of the second hole section 104 and the hole wall of the first hole section 103. The step surface between the first tappet section 203 and the second tappet section 204 is the first step surface 206. With the above technical solution, the first step surface 206 is the force-receiving surface. When the control oil in the control chamber 8 applies a thrust to the first step surface 206, this thrust can reduce the force applied by the tappet 2 to the needle valve core 5. By adjusting the magnitude of the oil pressure of the control oil in the control chamber 8, the force applied by the tappet 2 to the needle valve core 5 can be adjusted, and thus the opening pressure of the needle valve can be adjusted.

[0028] In some embodiments, the control valve chamber further includes a third hole section 102 located above the first hole section 103, and the spring 9 is located in the third hole section 102; the control valve chamber further includes a fourth hole section 101 located above the third hole section 102, and the pressure regulating screw 3 is threadedly engaged with the fourth hole section 101; the control valve chamber further includes a fifth hole section 105 located above the fourth hole section 101, and a sealing ring 12 is provided between the pressure regulating screw 3 and the hole wall of the fifth hole section 105. Providing the sealing ring 12 can improve the sealing performance and prevent leakage; the aperture of the third hole section 102 is larger than that of the first hole section 103.

[0029] In some embodiments, the tappet 2 further includes a shoulder 202 located above the first tappet segment 203. The shoulder 202 extends outwardly from the first tappet segment 203, and the lower end of the spring 9 is supported on the shoulder 202. The provision of the shoulder 202 is conducive to the vertical placement of the spring 9, ensuring the normal operation of the spring 9.

[0030] In some embodiments, the tappet 2 further includes a third tappet segment 201 located above the shoulder 202. The lower end of the pressure regulating screw 3 is provided with a first limiting portion for defining the upper dead center of the stroke of the third tappet segment 201. The provision of the third tappet segment 201 is conducive to the guiding of the spring 9, and the first limiting portion limits the lift of the tappet 2, ensuring the normal operation of the tappet 2.

[0031] In some embodiments, a first groove 301 for cooperating with the upper end portion of the third tappet segment 201 is provided at the first limiting portion. When the tappet 2 rises, the upper end portion of the third tappet segment 201 will contact the bottom surface of the first groove 301, ensuring the stable and reliable movement of the tappet 2.

[0032] In some embodiments, a second groove 205 is provided at the lower end of the tappet 2, and the upper end portion of the needle valve core 5 cooperates with the second groove 205. The cooperation between the second groove 205 and the upper end portion of the needle valve core 5 ensures the stable and reliable movement of the needle valve core 5.

[0033] In some embodiments, the upper end portion of the pressure regulating screw 3 is provided with an external hexagonal screw head, which is convenient for rotation during use. By rotating the external hexagonal screw head, the position of the pressure regulating screw 3 in the up and down directions is adjusted to achieve the effect of adjusting the pressure of the spring 9. Compared with the traditional marine fuel injection valve installation gasket for pressure regulation at the spring 9, using the pressure regulating screw 3 for pressure regulation can avoid disassembling the marine fuel injection valve, and the pressure adjustment can be achieved with simple tools, which is simple and fast. At the same time, thread pressure regulation can achieve stepless pressure regulation, while gasket pressure regulation requires the use of various specifications of gaskets, saving product costs.

[0034] Furthermore, a lock nut 13 can be installed on the upper part of the pressure regulating screw 3 to lock the position of the pressure regulating screw 3 by using the lock nut 13.

[0035] In some embodiments, the needle valve chamber includes a sixth hole section 401 and a seventh hole section 402 located below the sixth hole section 401. The aperture of the seventh hole section 402 is larger than that of the sixth hole section 401. The valve port 403 is located at the lower end of the seventh hole section 402. The needle valve core 5 includes a first needle valve core section 501 that cooperates with the sixth hole section 401 and a second needle valve core section 502 located below the first needle valve core section 501. The sealing portion 505 is provided at the lower end of the second needle valve core section 502. The outer diameter of the second needle valve core section 502 is smaller than that of the first needle valve core section 501. A pressure accumulation chamber 7 is formed between the inner wall of the seventh hole section 402 and the needle valve core 5. The step surface between the first needle valve core section 501 and the second needle valve core section 502 is the second step surface 504. When the pressure exerted by the fuel oil in the pressure accumulation chamber 7 on the second step surface 504 is large enough, the needle valve core 5 can be pushed to move upward.

[0036] In some embodiments, the needle valve core 5 further includes a third needle valve core section 503 located below the second needle valve core section 502. The third needle valve core section 503 extends into the fuel injection chamber 601. When the sealing portion 505 closes the valve port 403, the third needle valve core section 503 closes the fuel injection hole 602. When the sealing portion 505 opens the valve port 403, the third needle valve core section 503 opens the fuel injection hole 602. With the above technical solution, the third needle valve core section 503 can cut off the fuel in time at the end of injection, and there will be no problem of fuel droplets that are not atomized, resulting in incomplete fuel, increased emissions and fuel consumption.

[0037] In some embodiments, the needle valve core 5 further includes a fourth needle valve core section 506 located above the first needle valve core section 501. The outer diameter of the fourth needle valve core section 506 is smaller than that of the first needle valve core section 501. The upper end of the fourth needle valve core section 506 is used to support the lower end of the tappet 2. A second limiting portion for defining the upper dead point of the stroke of the step surface between the first needle valve core section 501 and the fourth needle valve core section 506 is provided in the valve housing.

[0038] In some embodiments, the valve housing includes a control valve housing 1, a needle valve housing 4, and a nozzle 6 connected in sequence from top to bottom. The control valve chamber is arranged in the control valve housing 1, the needle valve chamber is arranged in the needle valve housing 4, and the fuel injection chamber 601 is arranged in the nozzle 6.

[0039] In specific implementation, the first fuel oil passage section 106 in the control valve housing 1 and the second fuel oil passage section 404 in the needle valve housing 4 form a fuel oil passage, and the control oil passage 108 is arranged in the control valve housing 1. By using only one part, i.e., the control valve housing 1, the entry, flow, and distribution of fuel can be realized, and at the same time, the entry, flow, and distribution of control oil are also taken into account. Compared with traditional fuel injection valves, the functions of the injection valve cover and the injection valve housing are realized, simplifying the product structure and saving the assembly process. Additionally, since there is no connection between the injection valve cover and the injection valve housing, the integral injection valve housing structure is more firm and reliable, and at the same time, the use of seals at the connection is reduced, avoiding failure situations such as leakage.

[0040] In some embodiments, the first locking cap 10 fixedly connected to the control valve housing 1 presses the needle valve housing 4 upward against the control valve housing 1, and the needle valve housing 4 and the control valve housing 1 are sealed and connected. A planar sealing structure can be adopted between the needle valve housing 4 and the control valve housing 1 to form a seal. Using the first locking cap 10 to lock the needle valve housing 4 and the control valve housing 1 has the characteristics of simple structure and easy implementation.

[0041] In some embodiments, the second locking cap 11 fixedly connected to the needle valve housing 4 presses the nozzle 6 upward against the needle valve housing 4, and the nozzle 6 and the needle valve housing 4 are sealed and connected. A planar sealing structure can be adopted between the nozzle 6 and the needle valve housing 4 to form a seal. Using the second locking cap 11 to lock the nozzle 6 and the needle valve housing 4 has the characteristics of simple structure and easy implementation.

[0042] In specific implementation, mounting bolts 14 for fixedly installing the marine fuel injection valve can also be provided on the valve housing.

[0043] The following combines Figure 2 and Figure 3 to make a more specific description of the working principle of a marine fuel injection valve as described above: When the above-mentioned marine fuel injection valve is used as a traditional control injection valve, fuel oil enters from the fuel oil inlet 107 and is transported to the accumulator chamber 7 through the fuel oil passage. When the fuel oil pressure in the accumulator chamber 7 is greater than the first threshold, the needle valve core 5 moves upward, pushing the tappet 2 upward, compressing the spring 9, and at the same time, the valve port 403 opens, and the fuel oil enters the injection chamber 601, finally realizing injection. At this time, the control oil inlet 109 is blocked with a plug, and the control oil passage 108 is not enabled.

[0044] When the above marine fuel injection valve is used as an accurate control injection valve, the pressure of the spring 9 needs to be adjusted to be greater than the fuel pressure by rotating the pressure regulating screw 3. Fuel oil enters from the fuel oil inlet 107 and is transported to the accumulator chamber 7 through the fuel oil passage. At this time, the fuel oil pressure in the accumulator chamber 7 is not sufficient to overcome the pressure of the spring 9, and high-pressure control oil needs to be introduced from the control oil inlet 109. The high-pressure control oil pressure can overcome part of the spring 9 pressure, enabling the tappet 2 and the needle valve core 5 to move upward. The fuel pressure in the accumulator chamber 7 causes the needle valve core 5 to move upward, opening the valve port 403, and the fuel oil enters the injection chamber 601, finally realizing injection. At this time, the control oil inlet 109 is normally enabled and needs to be connected to external high-pressure control oil.

[0045] The present invention proposes a marine fuel injection valve that is compatible with accurate control and traditional control, and is applicable to both traditional control main engines and accurate control main engines. Using this fuel injection valve, without increasing costs, it can not only meet the fuel injection of traditional control marine low-speed engines, but also be applicable to the fuel injection of new accurate control marine low-speed engines during the later engine transformation, reducing the cost of replacing expensive accurate control injection valves during the transformation.

[0046] The marine fuel injection valve of the present invention has a simple, compact and ingenious structure. Compared with the previous accurate control injection valves, it has a lower manufacturing cost, a simpler structure, higher strength, can prevent problems such as fuel leakage and incomplete fuel combustion, is easier to adjust the pressure, and is easier to repair and maintain the product, with significant functional improvement and obvious economic benefits.

[0047] The marine fuel injection valve proposed by the present invention has a simple structure and fewer parts, with a lower cost compared to the previous accurate control fuel injection valves. At the same time, the internal channels of the injection valve are simple and clear, making maintenance and replacement convenient.

[0048] The pressure adjustment of the marine fuel injection valve proposed by the present invention is simple and convenient. Only by rotating the pressure regulating screw 3 can the pressure of the spring 9 be adjusted.

[0049] In the marine fuel injection valve proposed by the present invention, the special design of the pressure regulating screw 3 and the tappet 2 is beneficial to the stable and reliable operation of the spring 9, avoiding breakage caused by eccentric wear of the spring 9.

[0050] In the marine fuel injection valve proposed by the present invention, the special design of the needle valve pair ensures the normal operation of fuel injection, timely cuts off the fuel, and reduces fuel loss and emissions.

[0051] The marine fuel injection valve proposed by the present invention is applicable to traditional control main engines. By rotating the pressure regulating screw 3 and setting the opening pressure of the marine fuel injection valve to the requirements of the traditional control main engine, the function of the traditional fuel injection valve can be realized, that is, the needle valve core 5 only overcomes the force of the spring 9, injects when reaching the opening pressure, and closes when lower than the injection pressure.

[0052] The marine fuel injection valve proposed by the present invention is applicable to accurately control the main engine. By rotating the pressure regulating screw 3, the pressure of the spring 9 is adjusted to be greater than the fuel pressure. At this time, the fuel pressure alone is not sufficient to open the needle valve core 5. Then, in cooperation with the control oil system for accurately controlling the main engine, the control oil pressure is greater than the pressure of the spring 9, and the control oil controls the tappet 2 and the needle valve core 5 to rise, so as to realize the function of accurately controlling the fuel injection valve, that is, the control oil controls the opening and closing of the needle valve core 5, and the fuel injection volume is accurately controllable.

[0053] The above embodiments are only preferred embodiments given to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are within the protection scope of the present invention. In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples", etc. means that the specific features, structures, materials or characteristics of the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification.

Claims

1. A marine fuel injection valve, characterized in that: The invention comprises a valve housing, a pressure regulating screw, a spring, a push rod and a needle valve core, wherein the valve housing is provided with a control valve chamber, a needle valve chamber and an oil injection chamber which are connected in sequence from top to bottom, the valve housing is provided with an oil injection hole which is connected with the oil injection chamber, the lower end of the needle valve chamber is provided with a valve port, the pressure regulating screw is threadedly connected with the valve housing, the pressure regulating screw is used to adjust the compression amount of the spring, the push rod is slidably matched with the control valve chamber, a control chamber is provided between the push rod and the control valve chamber, a sealing part is provided on the needle valve core, the needle valve core is slidably matched with the needle valve chamber, a pressure storage chamber is provided between the needle valve core and the needle valve chamber, and the pressure storage chamber is located at the The upper side of the valve port; the upper end of the spring is supported upward on the pressure regulating screw, the lower end of the spring is supported downward on the push rod, the lower end of the push rod is supported downward on the needle valve core, the sealing portion is supported downward on the valve port, and the sealing portion closes the valve port to separate the pressure accumulation chamber and the injection chamber; a fuel oil channel for conveying fuel oil to the pressure accumulation chamber and a control oil channel for conveying control oil to the control chamber are provided in the valve housing, when the oil pressure of the fuel oil in the pressure accumulation chamber meets the first condition, the fuel oil in the pressure accumulation chamber pushes the needle valve core to move upward, and the valve port is opened to connect the pressure accumulation chamber and the injection chamber; When the control oil in the control chamber satisfies a second condition, the control oil in the control chamber applies an upward thrust to the tappet.

2. The marine fuel injection valve according to claim 1, characterized in that: The control valve chamber includes a first hole section and a second hole section located at the lower side of the first hole section, the push rod includes a first push rod section slidingly matched with the first hole section and a second push rod section matched with the second hole section, the aperture of the first hole section is larger than the aperture of the second hole section, the outer diameter of the first push rod section is larger than the outer diameter of the second push rod section, and the step surface between the first push rod section and the second push rod section, the step surface between the first hole section and the second hole section, the hole wall of the first hole section and the outer peripheral surface of the second push rod section form the control chamber.

3. The marine fuel injection valve according to claim 2, characterized in that: The control valve chamber also includes a third hole section located on the upper side of the first hole section, and the spring is located in the third hole section; the control valve chamber also includes a fourth hole section located on the upper side of the third hole section, and the pressure-adjusting screw is threadedly engaged with the fourth hole section; the control valve chamber also includes a fifth hole section located on the upper side of the fourth hole section, and a sealing ring is provided between the pressure-adjusting screw and the hole wall of the fifth hole section; the aperture of the third hole section is larger than the aperture of the first hole section.

4. The marine fuel injection valve according to claim 2, characterized in that: The push rod also includes a boss located on the upper side of the first push rod segment, the boss extends outward from the first push rod segment, and the lower end of the spring is supported on the boss; the push rod also includes a third push rod segment located on the upper side of the boss, and the lower end of the pressure regulating screw is provided with a first limiting portion for limiting the upper dead point of the stroke of the third push rod segment; the first limiting portion is provided with a first groove for cooperating with the upper end of the third push rod segment; the lower end of the push rod is provided with a second groove, and the upper end of the needle valve core cooperates with the second groove.

5. The marine fuel injection valve according to claim 1, characterized in that: The needle valve cavity includes a sixth hole segment and a seventh hole segment located below the sixth hole segment, the aperture of the seventh hole segment is larger than that of the sixth hole segment, the valve port is located at the lower end of the seventh hole segment, the needle valve core includes a first needle valve core segment matched with the sixth hole segment and a second needle valve core segment located below the first needle valve core segment, the sealing portion is arranged at the lower end of the second needle valve core segment, the outer diameter of the second needle valve core segment is smaller than the outer diameter of the first needle valve core segment, and the pressure storage cavity is surrounded by the hole wall of the seventh hole segment and the needle valve core.

6. The marine fuel injection valve according to claim 1, characterized in that: The needle valve core also includes a third needle valve core section located at the lower side of the second needle valve core section, and the third needle valve core section extends into the oil injection chamber; when the sealing portion closes the valve port, the third needle valve core section closes the oil injection hole; when the sealing portion opens the valve port, the third needle valve core section opens the oil injection hole.

7. The marine fuel injection valve according to claim 1, characterized in that: The needle valve core also includes a fourth needle valve core segment located on the upper side of the first needle valve core segment, the outer diameter of the fourth needle valve core segment is smaller than the outer diameter of the first needle valve core segment, and the upper end of the fourth needle valve core segment is used to support the lower end of the push rod; a second limiting portion is provided in the valve housing for limiting the upper dead point of the step surface between the first needle valve core segment and the fourth needle valve core segment.

8. The marine fuel injection valve according to claim 1, characterized in that: The valve housing comprises a control valve housing, a needle valve housing and a nozzle which are sequentially connected from top to bottom, the control valve chamber is arranged in the control valve housing, the needle valve chamber is arranged in the needle valve housing, and the oil injection chamber is arranged in the nozzle.

9. The marine fuel injection valve according to claim 8, characterized in that: The first locking cap fixedly connected to the control valve housing presses the needle valve housing upward onto the control valve housing, and the needle valve housing and the control valve housing are sealed.

10. The marine fuel injection valve according to claim 8, characterized in that: The second locking cap fixedly connected to the needle valve housing presses the nozzle upward onto the needle valve housing, and the nozzle and the needle valve housing are sealed.

Images