A marine fuel injection valve

Abstract

This invention relates to a marine fuel injection valve, comprising a valve body, an adjusting screw, a spring, a tappet, and a needle valve core. The valve body contains a control valve chamber, a needle valve chamber, and an injection chamber. A valve port is located at the lower end of the needle valve chamber. The adjusting screw is threaded to the valve body. The tappet slides within the control valve chamber, and a control chamber is located between the tappet and the control valve chamber. A sealing portion is located on the needle valve core, which slides within the needle valve chamber. A pressure accumulator chamber is located between the needle valve core and the needle valve chamber. The upper end of the spring is supported upwards on the adjusting screw, and the lower end of the spring is supported downwards on the tappet. The lower end of the tappet is supported downwards on the needle valve core, and the sealing portion is supported downwards on the valve port. The valve body contains a fuel oil passage for supplying fuel oil to the pressure accumulator chamber and a control oil passage for supplying control oil to the control chamber. This invention proposes a marine fuel injection valve that is compatible with both precise and conventional control methods, has a wide range of applications, and can reduce the cost of upgrading conventional main engines.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and more specifically to a marine fuel injection valve. Background Technology

[0002] There are two main approaches to fuel injection control for existing marine low-speed engines: the conventional control approach and the precision control approach.

[0003] Traditional control schemes use conventional marine fuel injection valves. The needle valve of a conventional marine fuel injection valve only overcomes the spring force, and injects fuel when the opening pressure is reached and closes when the pressure is lower. It is difficult to accurately control the fuel injection volume, but it has the advantage of low cost.

[0004] The precision control scheme uses control oil to control the opening and closing of the needle valve, making the fuel injection volume controllable. This can save fuel and reduce emissions to some extent, but it is more expensive.

[0005] With increasingly stringent emission regulations both domestically and internationally, and shipowners' demands for low fuel consumption in main engines, precision control solutions are gaining popularity. The marine fuel injection valves used in these precision control solutions are suitable for new main engines. When used in conjunction with the precision control system of a new main engine, they can precisely control the fuel injection volume to achieve high-efficiency operation of the main engine, thereby improving fuel efficiency and reducing emissions.

[0006] However, existing marine fuel injection valves, which are suitable for new main engines and precise control schemes, are expensive and complex in structure, and can only be used on main engines with precise control systems.

[0007] Currently, main engines using traditional control schemes still dominate the number of main engines. Upgrading these main engines will require replacing them with precision-controlled marine fuel injection valves, but for now, traditional marine fuel injection valves are still needed as a transition. Upgrading from traditional marine fuel injection valves to precision-controlled marine fuel injection valves is too costly. Summary of the Invention

[0008] The purpose of this invention is to provide a marine fuel injection valve to mitigate or eliminate at least one of the aforementioned problems.

[0009] This invention discloses a marine fuel injection valve, comprising a valve housing, a pressure adjusting screw, a spring, a tappet, and a needle valve core. The valve housing contains a control valve chamber, a needle valve chamber, and an injection chamber, which are sequentially connected from top to bottom. The valve housing has an injection hole communicating with the injection chamber. The lower end of the needle valve chamber has a valve port. The pressure adjusting screw is threaded to the valve housing and is used to adjust the compression of the spring. The tappet slides within the control valve chamber, and a control chamber is provided between the tappet and the control valve chamber. The needle valve core has a sealing portion and slides within the needle valve chamber. A pressure accumulator is provided between the needle valve core and the needle valve chamber, located above the valve port. The upper end of the spring... The spring is supported upward on the adjusting 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, and the sealing part is supported downward on the valve port. The sealing part closes the valve port to isolate the accumulator chamber and the injection chamber. The valve housing is provided with a fuel oil passage for supplying fuel oil to the accumulator chamber and a control oil passage for supplying control oil to the control chamber. When the fuel oil pressure in the accumulator chamber meets a first condition, the fuel oil in the accumulator chamber pushes the needle valve core upward, and the valve port opens to connect the accumulator chamber and the injection chamber. When the control oil in the control chamber meets a second condition, the control oil in the control chamber applies an upward thrust to the push rod.

[0010] Optionally, the control valve cavity includes a first bore section and a second bore section located below the first bore section. The push rod includes a first push rod section that slides with the first bore section and a second push rod section that slides with the second bore section. The diameter of the first bore section is larger than the diameter of the second bore section, and the outer diameter of the first push rod section is larger than the outer diameter of the second push rod section. The control cavity is formed by the stepped surface between the first push rod section and the second push rod section, the stepped surface between the first bore section and the second bore section, the bore wall of the first bore section, and the outer peripheral surface of the second push rod section.

[0011] Optionally, the control valve chamber further includes a third section located above the first section, with the spring located in the third section; the control valve chamber further includes a fourth section located above the third section, with the pressure adjusting screw threaded into the fourth section; the control valve chamber further includes a fifth section located above the fourth section, with a sealing ring provided between the pressure adjusting screw and the wall of the fifth section; the diameter of the third section is larger than the diameter of the first section.

[0012] Optionally, the push rod further includes a shoulder located on the upper side of the first push rod section, the shoulder extending outward from the first push rod section, and the lower end of the spring supported on the shoulder; the push rod further includes a third push rod section located on the upper side of the shoulder, the lower end of the adjusting screw is provided with a first limiting part for limiting the upper stop point of the stroke of the third push rod section; the first limiting part is provided with a first groove for engaging with the upper end of the third push rod section; the lower end of the push rod is provided with a second groove, and the upper end of the needle valve core engages with the second groove.

[0013] Optionally, the needle valve cavity includes a sixth orifice and a seventh orifice located below the sixth orifice. The diameter of the seventh orifice is larger than that of the sixth orifice. The valve port is located at the lower end of the seventh orifice. The needle valve core includes a first needle valve core segment that mates with the sixth orifice and a second needle valve core segment located below the first needle valve core segment. The sealing part is disposed at the lower end of the second needle valve core segment. The outer diameter of the second needle valve core segment is smaller than that of the first needle valve core segment. The orifice wall of the seventh orifice and the needle valve core form the accumulator cavity.

[0014] Optionally, the needle valve core further includes a third needle valve core section located below the second needle valve core section, the third needle valve core section extending into the fuel injection chamber; when the sealing part closes the valve port, the third needle valve core section closes the fuel injection hole; when the sealing part opens the valve port, the third needle valve core section 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 is smaller than the outer diameter of the first needle valve core segment. The upper end of the fourth needle valve core segment is used to support the lower end of the push rod. A second limiting part is provided inside the valve housing to limit the upper stop point of the travel of the stepped surface between the first needle valve core segment and the fourth needle valve core segment.

[0016] Optionally, the valve housing includes a control valve housing, a needle valve housing, and a nozzle connected sequentially from top to bottom. The control valve chamber is disposed within the control valve housing, the needle valve chamber is disposed within the needle valve housing, and the injection chamber is disposed within the nozzle.

[0017] Optionally, a 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 together.

[0018] Optionally, a second locking cap fixedly connected to the needle valve housing presses the nozzle upward onto the needle valve housing, creating a sealed connection between the nozzle and the needle valve housing.

[0019] This invention proposes a marine fuel injection valve that is compatible with both precision control and conventional control. It can meet the needs of both conventional main engines and main engines with precision control systems, and has a wide range of applications, which can reduce the cost of upgrading conventional main engines. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the marine fuel injection valve described in some embodiments;

[0021] Figure 2 This is one of the cross-sectional views of the marine fuel injection valve described in some embodiments;

[0022] Figure 3 This is a second cross-sectional view of the marine fuel injection valve described in some embodiments.

[0023] In the diagram, 1—control valve housing, 2—pushrod, 3—adjusting 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.

[0024] 101—Fourth orifice section, 102—Third orifice section, 103—First orifice section, 104—Second orifice section, 105—Fifth orifice section, 106—First fuel oil passage section, 107—Fuel oil inlet, 108—Control oil passage, 109—Control oil inlet.

[0025] 201—Third tappet section; 202—Shoulder; 203—First tappet section; 204—Second tappet section; 205—Second groove; 206—First step surface.

[0026] 301—First Groove

[0027] 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;

[0028] 601—Injection chamber, 602—Injection hole. Detailed Implementation

[0029] The embodiments of the present invention will be described below with reference to the accompanying 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 scope of protection of the present invention.

[0030] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0031] like Figures 1 to 3 The illustrated marine fuel injection valve includes a valve body, an adjusting screw 3, a spring 9, a tappet 2, and a needle valve core 5. The valve body contains a control valve chamber, a needle valve chamber, and an injection chamber 601 connected sequentially from top to bottom. The valve body has an injection hole 602 communicating with the injection chamber 601. A valve port 403 is located at the lower end of the needle valve chamber. The adjusting screw 3 is threaded to the valve body and is used to adjust the compression of the spring 9. The tappet 2 slides within the control valve chamber, and a control chamber 8 is located between the tappet 2 and the control valve chamber. A sealing part 505 is provided on the needle valve core 5, which slides within the needle valve chamber. A pressure accumulator 7 is located between the needle valve core 5 and the needle valve chamber, above the valve port 403. The upper end of the spring 9 faces... The upper support is on the pressure adjusting screw 3, the lower end of the spring 9 is supported downward on the push rod 2, the lower end of the push rod 2 is supported downward on the needle valve core 5, and the sealing part 505 is supported downward on the valve port 403. The sealing part 505 closes the valve port 403 to isolate the accumulator chamber 7 and the injection chamber 601. The valve body is provided with a fuel oil passage for supplying fuel oil to the accumulator chamber 7 and a control oil passage 108 for supplying control oil to the control chamber 8. When the oil pressure of the fuel oil in the accumulator chamber 7 meets the first condition, the fuel oil in the accumulator chamber 7 pushes the needle valve core 5 to move upward, and the valve port 403 opens to connect the accumulator 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.

[0032] By adopting the above technical solution, the marine fuel injection valve is compatible with both precision control and traditional control. It can meet the usage requirements of both traditional main engines and main engines with precision control systems, and has the characteristics of wide applicability, which can reduce the cost of upgrading traditional main engines.

[0033] In practical implementation, the valve body, adjusting screw 3, spring 9, push rod 2, and needle valve core 5 constitute a needle valve. The first condition refers to the fuel oil pressure in the accumulator chamber 7 being greater than the opening pressure of the needle valve. More specifically, the first condition refers to the fuel oil pressure in the accumulator chamber 7 being greater than a first threshold. At this time, the upward thrust exerted by the fuel oil in the accumulator chamber 7 on the needle valve core 5 is greater than the first combined force exerted on the needle valve core 5 in addition to this thrust, which is the resultant force of the force exerted by the push rod 2 on the needle valve core 5, the weight of the needle valve core 5, and the force between the needle valve core 5 and the valve body. By rotating the adjusting screw 3 to adjust the spring force of the spring 9, and by adjusting the control oil pressure in the control chamber 8, the force exerted by the push rod 2 on the needle valve core 5 can be adjusted, thereby adjusting the opening pressure of the needle valve. The second condition refers to the control oil pressure in the control chamber 8 being greater than 0. At this time, the control oil in the control chamber 8 exerts an upward thrust on the push rod 2.

[0034] As a specific example, the control valve cavity includes a first bore section 103 and a second bore section 104 located below the first bore section 103. The push rod 2 includes a first push rod section 203 that slides with the first bore section 103 and a second push rod section 204 that mates with the second bore section 104. The diameter of the first bore section 103 is larger than the diameter of the second bore section 104, and the outer diameter of the first push rod section 203 is larger than the outer diameter of the second push rod section 204. The step surface between the first push rod section 203 and the second push rod section 204, the step surface between the first bore section 103 and the second bore section 104, the bore wall of the first bore section 103, and the outer peripheral surface of the second push rod section 204 together form a control cavity 8. The step surface between the first push rod section 203 and the second push rod section 204 is a first step surface 206. Using the above technical solution, the first step surface 206 is the force-bearing 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 push rod 2 to the needle valve core 5. By adjusting the oil pressure of the control oil in the control chamber 8, the force applied by the push rod 2 to the needle valve core 5 can be adjusted, thereby adjusting the opening pressure of the needle valve.

[0035] In some embodiments, the control valve chamber further includes a third orifice 102 located above the first orifice 103, and the spring 9 is located in the third orifice 102; the control valve chamber further includes a fourth orifice 101 located above the third orifice 102, and the pressure adjusting screw 3 is threadedly engaged with the fourth orifice 101; the control valve chamber further includes a fifth orifice 105 located above the fourth orifice 101, and a sealing ring 12 is provided between the pressure adjusting screw 3 and the orifice wall of the fifth orifice 105. The sealing ring 12 can improve the sealing performance and prevent leakage; the orifice diameter of the third orifice 102 is larger than the orifice diameter of the first orifice 103.

[0036] In some embodiments, the push rod 2 further includes a shoulder 202 located on the upper side of the first push rod section 203. The shoulder 202 extends outward from the first push rod section 203, and the lower end of the spring 9 is supported on the shoulder 202. The shoulder 202 facilitates the vertical placement of the spring 9 and ensures the normal operation of the spring 9.

[0037] In some embodiments, the push rod 2 further includes a third push rod section 201 located on the upper side of the shoulder 202, and the lower end of the adjusting screw 3 is provided with a first limiting part for limiting the upper limit point of the stroke of the third push rod section 201; the third push rod section 201 is provided to facilitate the guidance of the spring 9, and the first limiting part limits the lift of the push rod 2 to ensure the normal operation of the push rod 2.

[0038] In some embodiments, a first groove 301 is provided at the first limiting part for engaging with the upper end of the third push rod section 201; when the push rod 2 rises, the upper end of the third push rod section 201 will contact the bottom surface of the first groove 301, ensuring that the push rod 2 moves stably and reliably.

[0039] In some embodiments, the lower end of the push rod 2 is provided with a second groove 205, and the upper end of the needle valve core 5 cooperates with the second groove 205. The cooperation between the second groove 205 and the upper end of the needle valve core 5 ensures that the movement of the needle valve core 5 is stable and reliable.

[0040] In some embodiments, the upper end of the pressure adjusting screw 3 is provided with an external hexagonal screw head for easy rotation during use. By rotating the external hexagonal screw head, the position of the pressure adjusting screw 3 in the vertical direction is adjusted, thereby adjusting the pressure of the spring 9. Compared to the traditional marine fuel injection valve where pressure is adjusted at the spring 9 using a gasket, using the pressure adjusting screw 3 eliminates the need to disassemble the marine fuel injection valve, allowing for pressure adjustment with simple tools—simple and quick. Furthermore, threaded pressure adjustment enables stepless pressure regulation, while gasket pressure adjustment requires the use of various gasket specifications, saving product costs.

[0041] Furthermore, a locking nut 13 can be installed on the upper part of the adjusting screw 3 to lock the position of the adjusting screw 3.

[0042] In some embodiments, the needle valve cavity includes a sixth orifice section 401 and a seventh orifice section 402 located below the sixth orifice section 401. The diameter of the seventh orifice section 402 is larger than the diameter of the sixth orifice section 401. The valve port 403 is located at the lower end of the seventh orifice section 402. The needle valve core 5 includes a first needle valve core section 501 that cooperates with the sixth orifice section 401 and a second needle valve core section 502 located below the first needle valve core section 501. A sealing portion 505 is disposed 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 the outer diameter of the first needle valve core section 501. The orifice wall of the seventh orifice section 402 and the needle valve core 5 form a pressure accumulator 7. The stepped surface between the first needle valve core section 501 and the second needle valve core section 502 is a second stepped surface 504. When the pressure applied to the second stepped surface 504 by the fuel oil in the pressure accumulator 7 is large enough, it can push the needle valve core 5 to move upward.

[0043] 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 extending into the injection chamber 601; when the sealing part 505 closes the valve port 403, the third needle valve core section 503 closes the injection port 602; when the sealing part 505 opens the valve port 403, the third needle valve core section 503 opens the injection port 602. Using the above technical solution, the third needle valve core section 503 can promptly cut off the fuel supply at the end of injection, preventing the generation of un-atomized fuel droplets, thus avoiding incomplete fuel production and increasing emissions and fuel consumption.

[0044] In some embodiments, the needle valve core 5 further includes a fourth needle valve core segment 506 located above the first needle valve core segment 501. The outer diameter of the fourth needle valve core segment 506 is smaller than the outer diameter of the first needle valve core segment 501. The upper end of the fourth needle valve core segment 506 is used to support the lower end of the push rod 2. A second limiting part is provided in the valve housing to define the upper limit point of the stroke of the stepped surface between the first needle valve core segment 501 and the fourth needle valve core segment 506.

[0045] In some embodiments, the valve housing includes a control valve housing 1, a needle valve housing 4, and a nozzle 6 connected sequentially from top to bottom. The control valve chamber is disposed within the control valve housing 1, the needle valve chamber is disposed within the needle valve housing 4, and the injection chamber 601 is disposed within the nozzle 6.

[0046] In practical 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 constitute the fuel oil passage, and the control oil passage 108 is disposed in the control valve housing 1. Using only the control valve housing 1, the entry, flow, and distribution of fuel can be achieved, while also controlling the entry, flow, and distribution of control oil. Compared to traditional fuel injection valves, it achieves the dual functions of the injection valve cover and injection valve housing, simplifying the product structure and saving assembly steps. Furthermore, since there is no connection between the injection valve cover and the injection valve housing, the integrated injection valve housing structure is more robust and reliable, while also reducing the use of seals at the connection points, avoiding failures such as leakage.

[0047] In some embodiments, a first locking cap 10, fixedly connected to the control valve housing 1, presses the needle valve housing 4 upward onto the control valve housing 1, creating a sealed connection between the needle valve housing 4 and the control valve housing 1. A planar sealing structure can be used to form a seal between the needle valve housing 4 and the control valve housing 1. Using the first locking cap 10 to lock the needle valve housing 4 and the control valve housing 1 has the advantages of simple structure and ease of implementation.

[0048] In some embodiments, the second locking cap 11, which is fixedly connected to the needle valve housing 4, presses the nozzle 6 upward onto the needle valve housing 4, creating a sealed connection between the nozzle 6 and the needle valve housing 4. A planar sealing structure can be used to form a seal between the nozzle 6 and the needle valve housing 4. Using the second locking cap 11 to lock the nozzle 6 and the needle valve housing 4 has the advantages of simple structure and ease of implementation.

[0049] In practical implementation, mounting bolts 14 for fixing the marine fuel injection valve can also be provided on the valve body.

[0050] The following combination Figure 2 and Figure 3 A more detailed explanation of the working principle of one of the above-mentioned marine fuel injection valves is provided below:

[0051] When the aforementioned marine fuel injection valve is used as a conventional control injection valve, fuel oil enters through fuel oil inlet 107 and is transported to the accumulator chamber 7 via the fuel oil passage. When the fuel oil pressure in the accumulator chamber 7 exceeds a first threshold, the needle valve core 5 moves upward, pushing the push rod 2 upward and compressing the spring 9. Simultaneously, the valve port 403 opens, allowing fuel oil to enter the injection chamber 601, ultimately achieving injection. At this time, the control oil inlet 109 is blocked, and the control oil passage 108 is not activated.

[0052] When the aforementioned marine fuel injection valve is used as a precision control injection valve, the pressure of spring 9 needs to be adjusted to be greater than the fuel pressure by rotating the pressure adjusting screw 3. Fuel oil enters from 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 insufficient to overcome the pressure of spring 9, so 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, allowing the tappet 2 and 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 fuel oil enters the injection chamber 601, ultimately achieving injection. At this time, the control oil inlet 109 is normally activated and needs to be connected to an external high-pressure control oil source.

[0053] This invention proposes a marine fuel injection valve compatible with both precision and conventional control systems. It is suitable for both conventionally controlled and precision-controlled main engines. Using this fuel injection valve, fuel injection for conventionally controlled marine low-speed engines can be achieved without increasing costs, and it can also be adapted for new precision-controlled marine low-speed engines during later engine retrofits, reducing the cost of replacing expensive precision-controlled injection valves during retrofits.

[0054] The marine fuel injection valve of this invention has a simple, compact structure and ingenious design. Compared with previous precision control injection valves, it has lower manufacturing costs, a simpler structure, and higher strength. It can prevent fuel leakage and incomplete fuel combustion, is easier to regulate pressure, and is easier to inspect and maintain, resulting in significant functional improvements and obvious economic benefits.

[0055] The marine fuel injection valve proposed in this invention has a simple structure and fewer parts, and is less expensive than previous precision control fuel injection valves. At the same time, the internal channels of the injection valve are simple and clear, making maintenance and replacement convenient.

[0056] The pressure adjustment of the marine fuel injection valve proposed in this invention is simple and convenient; the pressure of the spring 9 can be adjusted simply by rotating the pressure adjusting screw 3.

[0057] In the marine fuel injection valve proposed in this invention, the special design of the pressure adjusting screw 3 and the tappet 2 is conducive to the stable and reliable operation of the spring 9 and avoids the spring 9 from breaking due to uneven wear.

[0058] In the marine fuel injection valve proposed in this invention, the special design of the needle valve assembly ensures the normal operation of fuel injection, cuts off fuel in a timely manner, and reduces fuel loss and emissions.

[0059] The marine fuel injection valve proposed in this invention is suitable for traditional control hosts. By rotating the pressure adjusting screw 3, the opening pressure of the marine fuel injection valve can be set to the requirements of the traditional control host, thus realizing the function of the traditional fuel injection valve. That is, the needle valve core 5 overcomes the force of the spring 9, and injects when the opening pressure is reached, and closes when the injection pressure is lower.

[0060] The marine fuel injection valve proposed in this invention is suitable for precise control of the main engine. By rotating the pressure adjusting 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 insufficient to open the needle valve core 5. In conjunction with the control oil system of the precise control main engine, the control oil pressure is greater than the spring 9 pressure. The control oil controls the rise of the push rod 2 and the needle valve core 5, thereby realizing the function of precise control of the fuel injection valve. That is, the needle valve core 5 is opened and closed by the control oil, and the fuel injection volume is precisely controllable.

[0061] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., means that a specific feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions 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 suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

Claims

1. A marine fuel injection valve, characterized in that, The device includes a valve housing, a pressure adjusting screw, a spring, a tappet, and a needle valve core. The valve housing contains a control valve chamber, a needle valve chamber, and an injection chamber, which are connected sequentially from top to bottom. The valve housing has an injection hole communicating with the injection chamber. The lower end of the needle valve chamber has a valve port. The pressure adjusting screw is threaded to the valve housing and is used to adjust the compression of the spring. The tappet slides within the control valve chamber, and a control chamber is provided between the tappet and the control valve chamber. The needle valve core has a sealing portion and slides within the needle valve chamber. A pressure accumulator chamber is provided between the needle valve core and the needle valve chamber. The pressure accumulator chamber is located within the... The upper side of the valve port; the upper end of the spring is supported upward on the pressure adjusting 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 part is supported downward on the valve port, and the sealing part closes the valve port to isolate the accumulator chamber and the injection chamber; the valve housing is provided with a fuel oil passage for supplying fuel oil to the accumulator chamber and a control oil passage for supplying control oil to the control chamber; when the oil pressure of the fuel oil in the accumulator chamber meets the first condition, the fuel oil in the accumulator chamber pushes the needle valve core to move upward, and the valve port opens to connect the accumulator 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; the control valve chamber includes a first orifice and a second orifice located below the first orifice, the push rod includes a first push rod section that slides with the first orifice and a second push rod section that mates with the second orifice, the orifice diameter of the first orifice is larger than the orifice diameter of the second orifice, 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 orifice and the second orifice, the orifice wall of the first orifice and the outer peripheral surface of the second push rod section form the control chamber.

2. The marine fuel injection valve according to claim 1, characterized in that, The control valve chamber further includes a third section located above the first section, and the spring is located in the third section; the control valve chamber further includes a fourth section located above the third section, and the pressure adjusting screw is threaded into the fourth section; the control valve chamber further includes a fifth section located above the fourth section, and a sealing ring is provided between the pressure adjusting screw and the wall of the fifth section; the diameter of the third section is larger than the diameter of the first section.

3. The marine fuel injection valve according to claim 1, characterized in that, The push rod further includes a shoulder located on the upper side of the first push rod section, the shoulder extending outward from the first push rod section, and the lower end of the spring supported on the shoulder; the push rod further includes a third push rod section located on the upper side of the shoulder, the lower end of the adjusting screw is provided with a first limiting part for limiting the upper stop point of the stroke of the third push rod section; the first limiting part is provided with a first groove for engaging with the upper end of the third push rod section; the lower end of the push rod is provided with a second groove, and the upper end of the needle valve core engages with the second groove.

4. The marine fuel injection valve according to claim 1, characterized in that, The needle valve cavity includes a sixth orifice and a seventh orifice located below the sixth orifice. The diameter of the seventh orifice is larger than that of the sixth orifice. The valve port is located at the lower end of the seventh orifice. The needle valve core includes a first needle valve core segment that mates with the sixth orifice and a second needle valve core segment located below the first needle valve core segment. The sealing part is disposed at the lower end of the second needle valve core segment. The outer diameter of the second needle valve core segment is smaller than that of the first needle valve core segment. The accumulator cavity is formed between the wall of the seventh orifice and the needle valve core.

5. The marine fuel injection valve according to claim 4, characterized in that, The needle valve core also includes a third needle valve core section located below the second needle valve core section, the third needle valve core section extending into the fuel injection chamber; when the sealing part closes the valve port, the third needle valve core section closes the fuel injection hole; when the sealing part opens the valve port, the third needle valve core section opens the fuel injection hole.

6. The marine fuel injection valve according to claim 4, characterized in that, The needle valve core also 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 is smaller than the outer diameter of the first needle valve core segment. The upper end of the fourth needle valve core segment is used to support the lower end of the push rod. A second limiting part is provided inside the valve housing to limit the upper dead point of the travel of the stepped surface between the first needle valve core segment and the fourth needle valve core segment.

7. The marine fuel injection valve according to claim 1, characterized in that, The valve housing includes a control valve housing, a needle valve housing, and a nozzle connected sequentially from top to bottom. The control valve chamber is disposed within the control valve housing, the needle valve chamber is disposed within the needle valve housing, and the injection chamber is disposed within the nozzle.

8. The marine fuel injection valve according to claim 7, characterized in that, A first locking cap, which is 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 together.

9. The marine fuel injection valve according to claim 7, characterized in that, A second locking cap, which is fixedly connected to the needle valve housing, presses the nozzle upward onto the needle valve housing, and a sealed connection is formed between the nozzle and the needle valve housing.

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