Fuel injector flow restriction device
By designing a fuel injector flow limiting device and using a drain passage and stepped structure to control fuel flow, the problem of uneven fuel distribution in large diesel engine injectors was solved, improving combustion efficiency and engine safety, and preventing engine accidents caused by abnormal fuel.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- 重油高科电控燃油喷射系统有限公司
- Filing Date
- 2023-11-15
- Publication Date
- 2026-06-12
AI Technical Summary
Uneven fuel flow in large diesel engine injectors leads to inconsistent air-fuel mixture concentration, affecting engine combustion efficiency and safety, and may cause engine vibration, noise, and overheating damage.
A fuel injector flow limiting device was designed, including a valve body, valve seat, valve sleeve and spring. It controls the fuel flow through a drain passage and stepped structure to ensure stable injection under normal conditions and block fuel flow under abnormal conditions to prevent accidents.
It achieves stable control of fuel flow, improves fuel atomization and combustion efficiency, prevents engine malfunctions caused by too much or too little fuel, and ensures engine safety and stability.
Smart Images
Figure CN117345495B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of fuel injector technology, and more particularly to fuel injector flow limiting devices. Background Technology
[0002] As emission regulations become increasingly stringent, large diesel engines are increasingly adopting electronically controlled high-pressure common rail injection systems to meet engine emission requirements. Common rail electronic fuel injection technology generates a constant high-pressure fuel directly or indirectly through the common rail, distributing it to each injector. By utilizing the opening and closing of high-speed electromagnetic valves integrated into each injector, the amount of fuel injected into the diesel engine's combustion chamber is controlled in a timely and quantitative manner. This ensures optimal combustion ratios, good atomization, optimal ignition timing, sufficient ignition energy, and minimal emissions. Since large diesel engines are primarily used in generator sets and on ships, are expensive, and have extremely high safety requirements, the reliability and safety of the electronically controlled high-pressure common rail injectors are of paramount importance.
[0003] Large diesel engine injectors, due to their high flow rate, can experience uneven fuel injection due to pressure fluctuations and pipeline resistance, leading to inconsistent air-fuel mixture concentrations and affecting engine combustion efficiency. Uneven fuel injection also results in uneven combustion across the cylinders, potentially causing engine vibration and noise. Excessive fuel injection can lead to an overly rich mixture, resulting in incomplete combustion and increased fuel consumption. Furthermore, malfunctions in the fuel injection control mechanism or jamming of the injector assembly can cause excessive fuel injection into the combustion chamber, potentially leading to engine overheating, piston meltdown, and engine damage.
[0004] Therefore, providing a flow limiting device for fuel injectors with a stable flow limiting effect has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention
[0005] The purpose of this invention is to provide a fuel injector flow limiting device that has a stable flow limiting effect.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0007] A fuel injector flow limiting device includes a valve body, a valve seat, a valve sleeve, and a spring 1. The valve body has a hollow tube structure, including an oil inlet end on the left and an oil outlet end on the right. On the oil outlet end side, a first step and a second step are sequentially arranged inside the valve body, and an oil outlet 1 is provided on the right side of the second step. A valve seat is fixedly arranged on the oil inlet end side, and a first through hole is provided in the valve seat. A flow limiting step is provided in the first through hole. The valve seat and the valve body form a valve cavity for the valve sleeve to reciprocate. A first countersunk hole is provided on the right side of the valve sleeve, and the left side of the spring is arranged in the first countersunk hole, with the right side of the spring abutting against the second step. An oil drain channel is provided on the outer wall of the valve sleeve. One end of the oil drain channel is connected to the first through hole, and the other end of the oil drain channel is connected to the oil outlet through the valve cavity.
[0008] Furthermore, the right end face of the valve sleeve corresponds to the first step, and under the drive of fuel flow pressure, the right end face of the valve sleeve and the first step form an end face seal.
[0009] Furthermore, a second countersunk hole is provided on the left side of the valve sleeve, and the oil drain passage is connected to the first through hole through the second countersunk hole.
[0010] Furthermore, the outer wall of the valve sleeve is symmetrically provided with multiple oil drain channels.
[0011] Furthermore, the oil drain passage includes a first oil drain passage and a second oil drain passage that are interconnected; wherein the first oil drain passage is arranged along the radial direction of the valve sleeve, and the second oil drain passage is arranged along the axial direction of the valve sleeve.
[0012] Furthermore, the first drain passage is inclined along the axial direction of the valve sleeve, and its inclination is 45°-62°.
[0013] Furthermore, a notch is provided on the right end face of the outer wall of the valve sleeve.
[0014] Furthermore, an enlarged portion is provided inside the valve body on the left side of the first step.
[0015] Compared with existing technologies, the beneficial effects achieved by this invention are as follows: Through the cooperation of the valve body, valve sleeve, and spring, the injector flow limiting device can maintain stable fuel pressure within the injector when the fuel flow is normal, thereby ensuring effective fuel atomization and improving fuel combustion efficiency and degree. When the high-pressure fuel flow is abnormally high, it can block fuel from flowing out of the valve body and into the injector after entering the outlet. In other words, by using the injector flow limiting device to restrict the fuel flow, the maximum injection flow of the injector is controlled. Furthermore, when a malfunction occurs in the electronically controlled injector, resulting in direct fuel flow into the combustion chamber, the fuel supply to the injector is cut off, preventing or amplifying accidents. Attached Figure Description
[0016] Figure 1 This is a schematic cross-sectional view of the injector flow limiting device of the present invention;
[0017] Figure 2 This is a schematic cross-sectional view of the injector flow limiting device of the present invention when it is closed;
[0018] Figure 3 This is a schematic diagram of the valve sleeve in this invention;
[0019] Figure 4 This is a schematic cross-sectional view of the valve sleeve in this invention. Figure 1
[0020] Figure 5 This is a diagram illustrating the application scenario of the injector flow limiting device of the present invention.
[0021] Explanation of reference numerals in the attached drawings: Valve body 100; First step 1011; Second step 102; Oil outlet 103; Valve cavity 104; Valve seat 200; First through hole 201; Valve sleeve 300; First countersunk hole 301; Oil drain passage 302; First oil drain passage 30211; Second oil drain passage 30221; Second countersunk hole 303; Spring 400; Injector body 600; Filter structure 700. Detailed Implementation
[0022] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.
[0023] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.
[0024] In the description of this specification, the references to "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0025] As attached Figure 1-5 As shown, this application discloses an injector flow limiting device, which includes a valve body 100, a valve seat 200, a valve sleeve 300, and a spring 400; wherein the valve body 100 has a hollow tube sleeve structure, including an oil inlet end on the left and an oil outlet end on the right; on the oil outlet end side, a first step 101 and a second step 102 are sequentially arranged inside the valve body 100, and an oil outlet 103 is arranged on the right side of the second step 102; the valve seat 200 is fixedly arranged at the oil inlet end, and a first through hole 201 is provided inside the valve seat 200. A flow-limiting step is provided inside the through hole 201; and the valve seat 200 and the valve body 100 form a valve cavity 104 for the valve sleeve 300 to move back and forth; a first countersunk hole 301 is provided on the right side of the valve sleeve 300, and the spring 400 is provided on the left side in the first countersunk hole 301, and the right side of the spring 400 abuts against the second step 102; an oil drain passage 302 is provided on the outer wall of the valve sleeve 300, one end of the oil drain passage 302 is connected to the first through hole 201, and the other end of the oil drain passage 302 is connected to the oil outlet 103 through the valve cavity 104.
[0026] As described above, the injector flow restrictor device includes a valve body 100 made of stainless steel or carbon steel to withstand the high pressure and high temperature operating environment of the injector flow restrictor structure. The valve body 100 has a hollow tube-like structure, with one end for oil inlet and the other end for oil outlet. A valve seat 200 is fixedly installed at the oil inlet end of the valve body 100. Specifically, the valve seat 200 can be fixed to the end of the valve body 100 by interference fit. A first through hole 201 is also provided at the valve seat 200 for oil inlet. A flow restricting step is also provided inside the first through hole 201. Specifically, two stepped surfaces are provided inside the first through hole 201, so that the inner diameter of the first through hole 201 gradually decreases away from the oil inlet end. On the oil outlet side of the valve body 100, a first step 101 and a second step 102 are sequentially provided inside the valve body 100, so that the inner diameter of the valve body 100 gradually decreases away from the oil inlet end. A valve sleeve 300 is provided inside the valve body 100, and the valve sleeve 300 and the valve cavity 104 are fitted with a small clearance. The valve body 100 and the valve seat 200 provided at the end of the valve body 100 form the valve cavity 104, which allows the valve sleeve 300 to move back and forth. A first countersunk hole 301 is provided on the right side of the valve sleeve 300, and the inner diameter of the first countersunk hole 301 matches the outer diameter of the spring 400, so that the end of the spring 400 can be inserted into the first countersunk hole 301. The right side of the spring 400 abuts against the second step 102 provided on the oil outlet side of the valve body 100. The displacement of the spring 400 is restricted by the cooperation of the first countersunk hole 301 and the second step 102, preventing the spring 400 from falling out of the valve sleeve 300. Furthermore, neither end of the spring 400 is fixedly connected, so as to maintain the good elastic performance of the spring 400 and quickly absorb and release energy. The outer wall of the valve sleeve 300 is provided with an oil drain passage 302. One end of the oil drain passage 302 is connected to the first through hole 201, and the other end of the oil drain passage 302 is connected to the oil outlet located on the right side of the valve body 100 through the valve cavity 104. When assembling this injector flow limiting device, firstly, the spring 400 is placed into the first countersunk hole 301 of the valve sleeve 300, then the valve sleeve 300 and the spring 400 are placed into the valve body 100, so that the spring 400 abuts against the second step 102 to limit the position of the spring 400 and the valve sleeve 300; finally, the valve seat 200 is interference-fitted to the oil inlet end of the valve body 100, so that the first through hole 201 is connected to the oil drain passage 302.
[0027] When the fuel flow rate is normal, fuel enters the valve body 100 through the first through-hole 201. Since the drain passage 302 is connected to the first through-hole 201, the fuel flows through the first through-hole 201 and then into the drain passage 302. Because the drain passage 302 is the smallest flow orifice of fuel in the fuel injector flow restrictor, the flow pressure of the fuel is reduced, and it flows through the valve chamber 104 and then out of the valve body 100 through the outlet 103 to participate in the subsequent operation of the fuel injector. When the fuel flow rate is too high, it will push the valve sleeve 200 to overcome the elastic force of the spring 400 and move towards the outlet in the valve chamber 104. This reduces the distance between the valve sleeve 300 and the first step 101, thus reducing the fuel flow path from the valve chamber 104 to the outlet 103 and preventing excessive fuel from flowing out of the valve body 100 and into the fuel injector, which would affect the normal operation of the fuel injector. When the fuel flow rate is normal, the fuel injector flow restrictor can maintain a stable fuel pressure inside the injector, thereby ensuring the fuel atomization effect and improving the fuel combustion efficiency and combustion degree.
[0028] In further optimization, in other embodiments of this application, the right end face of the valve sleeve 300 corresponds to the first step 101, and under the drive of fuel flow pressure, the right end face of the valve sleeve and the first step 101 form an end face seal. When the injector malfunctions, i.e., the high-pressure fuel flow is abnormally large, when the fuel flowing through the injector flow restrictor enters the drain passage 301 in the injector flow restrictor sleeve 300 from the first through hole 301 in the valve seat 200, since the drain passage 301 is the smallest flow orifice of fuel in the injector flow restrictor, the fuel flow pressure increases, indicating that the fuel is throttled at the drain passage 302, and the fuel flow is obstructed. At this time, the fuel pressure acting on the end of the valve sleeve 200 overcomes the spring force of the spring 400, rapidly compressing the spring 400. Under the action of the fuel flow pressure, the valve sleeve 200 will overcome the spring force and move to the right, bringing the right end face of the valve sleeve 200 into contact with the first step 101 of the valve body 100, forming an end face seal. This prevents fuel from entering the outlet 103 and flowing out of the valve body 100 into the injector. By using the injector flow limiting device to restrict the fuel flow, the maximum injection flow of the injector can be controlled. In the event of a malfunction in the electronically controlled injector causing fuel to flow directly into the combustion chamber, the fuel supply to the injector is cut off to prevent or amplify an accident.
[0029] In further optimization, in other embodiments of this application, a second countersunk hole 303 is provided on the left side of the valve sleeve 300, and the oil drain passage 302 communicates with the first through hole 201 through the second countersunk hole 303. The second countersunk hole 303 is located at the center of the end of the valve sleeve 300 and is coaxially arranged with the first through hole 201. The oil drain passage 302 communicates with the first through hole 201 through the second countersunk hole 303. That is, when fuel enters the valve body 100 from the first through hole 201, it flows through the second countersunk hole 303 and then into the oil drain passage 302. Specifically, the second countersunk hole 303 is a blind hole machined from the right end of the valve sleeve 300 facing the inside of the valve sleeve 300. Because it is coaxially arranged with the first through hole 201, the fuel flows directly into the second countersunk hole 303 after passing through the first through hole 201, and the fluid pressure of the fuel directly impacts the end face of the second countersunk hole 303. When fuel flows through the valve sleeve 300, compared to the end face of the valve sleeve 300 without a countersunk hole, the same fuel flow rate passing through the end face of the smaller second countersunk hole 303 results in a greater fuel impact force on the valve sleeve 300. This increases the force of the valve sleeve 300 overcoming the spring 400, making it easier to control the rightward displacement of the valve sleeve 300. It also allows for better control of the fluid passage opening between the valve sleeve 300 and the first step 101, thus enabling more precise control of the fuel flow rate from the injector flow restrictor.
[0030] As attached Figure 5 As shown, in further optimization, in other embodiments of this application, the outer wall of the valve sleeve 300 is symmetrically provided with multiple oil drain channels 302. The oil drain channels 302 are located on the outer wall of the valve sleeve 300. Specifically, the oil drain channels 302 are formed by cutting a portion of the outer wall of a cylindrical structural member along the axial direction, for the flow of fuel. By providing multiple oil drain channels 302 on the outer wall of the valve sleeve 300, the oil drain area can be increased, allowing fuel to be discharged more quickly and evenly. Furthermore, the force on the valve sleeve 300 is made uniform throughout, ensuring greater stability of the valve sleeve 300 structure during use and extending the service life of the valve sleeve 300, thus extending the service life of the injector flow limiting device.
[0031] In further optimization, in other embodiments of this application, the oil drain passage 302 includes a first oil drain passage 3021 and a second oil drain passage 3022 that are interconnected, wherein the first oil drain passage 3021 is arranged along the radial direction of the valve sleeve 300, and the second oil drain passage 3022 is arranged along the axial direction of the valve sleeve 300. The oil drain passage 302 is an oil passage provided on the outer wall of the valve sleeve 300. Specifically, the oil drain passage 302 is formed by cutting a portion of the cylindrical outer wall of the valve sleeve 300 along the axial direction. By dividing the oil drain channel 302 into a first oil drain channel 3021 and a second oil drain channel 3022, wherein the first oil drain channel 3021 is a channel arranged radially along the valve sleeve 300 and the second oil drain channel 3022 is a channel arranged axially along the valve sleeve 300, the valve sleeve 300 can be machined parallel to the radial direction of the valve sleeve 300 end face and the axial direction of its side wall using a cutting tool when machining the oil drain channel 302. Compared with the integrated oil drain channel 300, the split oil drain channel 302 is easier to machine, which not only reduces the machining time but also improves the machining quality of the oil drain channel 302.
[0032] As attached Figure 3 As shown, in other embodiments of this application, the first oil drain passage 3021 is inclined along the axial direction of the valve sleeve 300, and its inclination angle is 45°-62°. Inclining the first oil drain passage 3021 along the axial direction of the valve sleeve 300 means that the first oil drain passage 3021 is set as a slope, and this slope guides the fuel flow to the second oil drain passage 3022. The sloped first oil drain passage 3021 can better guide the fuel flow to the second oil drain passage 3022, making it less likely for fuel to accumulate in the first oil drain passage 3021, allowing the fuel to flow more smoothly in the valve sleeve 300, thus improving the working efficiency of the injector flow restrictor.
[0033] Further optimization is possible in other embodiments of this application, where a notch can be provided on the outer wall of the right end face of the valve sleeve 300. When the fuel flow through the injector flow restrictor is too large, the valve sleeve 300 will overcome the spring force and move to the right, causing the right end face of the valve sleeve 300 to abut against the first step 101 to form an end face seal, thereby isolating the fuel from the outlet 103. The sealing performance between the right end face of the valve sleeve 300 and the first step 101 is determined by factors such as the flatness and roughness of the first step 101 and the right end face. To ensure a good sealing effect, the right end face of the valve sleeve 300 and the first step 101 need to be machined into an absolute plane. By providing a notch on the outer wall of the right end face of the valve sleeve 300, the area of the right end face is reduced, thus reducing the machining difficulty of the right end face as a sealing plane. This reduces the machining cost of the valve sleeve 300 and the injector flow restrictor while ensuring the sealing effect.
[0034] In further optimization, in other embodiments of this application, an enlarged portion is provided within the valve body 100 on the left side of the first step 101. The enlarged portion is a cavity on the left side of the first step 101 with an inner diameter greater than the length of the first step 101. Since the first step 101 needs to mate with the right end face of the valve sleeve 300 to achieve an end-face seal, ensuring the flatness of the first step 101 is a primary consideration when machining it. By providing an enlarged portion on the left side of the first step 101, machining the first step 101 within the valve body 100 becomes more convenient, improving the machining efficiency of the first step 101, thus increasing the machining efficiency of the injector flow limiting device.
[0035] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A fuel injector flow limiting device, characterized in that: The valve body (100), valve seat (200), valve sleeve (300), and spring (400) are included. The valve body (100) has a hollow tube structure, including an oil inlet end on the left and an oil outlet end on the right. On the oil outlet end side, a first step (101) and a second step (102) are sequentially arranged inside the valve body (100), and an oil outlet (103) is arranged on the right side of the second step (102). The valve seat (200) is fixedly arranged at the oil inlet end, and a first through hole (201) is provided inside the valve seat (200), and a flow limiting device is provided inside the first through hole (201). The valve seat (200) and valve body (100) form a valve cavity (104) for the valve sleeve (300) to reciprocate; a first countersunk hole (301) is provided on the right side of the valve sleeve (300), and a spring (400) is provided on the left side inside the first countersunk hole (301), and the right side of the spring (400) abuts against the second step (102); an oil drain passage (302) is provided on the outer wall of the valve sleeve (300), one end of the oil drain passage (302) is connected to the first through hole (201), and the other end of the oil drain passage (302) is connected to the oil outlet (103) through the valve cavity (104); The right end face of the valve sleeve (300) corresponds to the first step (101). Under the drive of fuel flow pressure, the right end face of the valve sleeve (300) and the first step (101) form an end face seal. The valve sleeve (300) is provided with a second countersunk hole (303) on the left side, and the oil drain passage (302) is connected to the first through hole (201) through the second countersunk hole (303); The oil drain passage (302) includes a first oil drain passage (3021) and a second oil drain passage (3022) that are interconnected; wherein the first oil drain passage (3021) is arranged in the radial direction of the valve sleeve (300), and the second oil drain passage (3022) is arranged in the axial direction of the valve sleeve (300).
2. The injector flow limiting device according to claim 1, characterized in that: The valve sleeve (300) has multiple oil drain channels (302) symmetrically arranged on its outer wall.
3. The injector flow limiting device according to claim 1, wherein the first drain passage (3021) is inclined along the axial direction of the valve sleeve (300), and its inclination is 45°-62°.
4. The injector flow limiting device according to claim 1, 2 or 3, wherein a notch is provided on the outer wall of the right end face of the valve sleeve (300).
5. The injector flow limiting device according to claim 1, 2 or 3, characterized in that: An enlarged portion is provided inside the valve body (100) on the left side of the first step (101).
6. The injector flow limiting device according to claim 4, characterized in that: An enlarged portion is provided inside the valve body (100) on the left side of the first step (101).