Needle-valve-free prepressing spring diesel injector
By installing an inner filter element and a central mesh reinforcement cylinder inside the fuel inlet pipe joint of the diesel injector, designing the fluid passage as a frustum-shaped pressure buffer, optimizing the flow structure, and setting an anti-slip layer on the surface of the inner filter element, the problems of wear, slow response, and impurity entry of traditional diesel injectors are solved, achieving efficient filtration and convenient maintenance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NANYANG TENGCHI CHAIYE MACHINERY CO LTD
- Filing Date
- 2025-06-13
- Publication Date
- 2026-05-12
AI Technical Summary
Traditional diesel injectors suffer from problems such as needle valve wear, slow response speed, and impurities entering and affecting the engine. Existing technologies have problems such as complex needle valve structure design and installation methods.
In the diesel injection system, a needle-free valve structure is adopted. An inner filter element is set in the oil inlet pipe joint. The inner filter element has an oil channel. The central mesh reinforcement cylinder and the oil filter screen form a filtration structure. The liquid passage is designed as a frustum-shaped pressure buffer. The front expansion chamber and the outer expansion chamber optimize the flow. The surface of the inner filter element is provided with an anti-slip layer for easy replacement.
It achieves effective filtration of diesel injector fluid, prevents impurities from entering, extends engine life, ensures the safety of the fuel system, simplifies the filter cartridge replacement process, and improves filtration efficiency and maintenance convenience.
Smart Images
Figure CN224228772U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of diesel injector technology, and more specifically, to a needle-valve-less preload spring diesel injector. Background Technology
[0002] During the operation of a diesel engine, the fuel injector, as the core component of the fuel injection system, plays a decisive role in the engine's power, economy, and emission characteristics. Traditional diesel fuel injectors typically employ a needle valve structure, relying on the opening and closing of the needle valve to achieve fuel injection and cutoff. When the needle valve is in operation, it needs to overcome the pressure of the preload spring through a complex hydraulic drive system to achieve precise opening and closing actions.
[0003] However, this traditional needle valve injector has many problems. First, the long-term high-frequency impact and friction between the needle valve and the valve seat can easily lead to wear, affecting the injector's sealing performance and service life, which in turn causes deviations in fuel injection quantity and reduces engine combustion efficiency. Second, the opening and closing response speed of the needle valve is limited, making it difficult to meet the requirements of modern diesel engines for fast and precise fuel injection control. Especially when engine operating conditions change frequently, it cannot adjust the injection timing and quantity in time, resulting in incomplete combustion, increased fuel consumption, and pollutant emissions.
[0004] To avoid the aforementioned problems, invention patent CN109098907A discloses a diesel injector without a needle valve preload spring. Its key feature is that the injector control valve seat adopts a long-hole T-shaped column structure, with liquid controlling the hydraulic pressure at the tail of the needle valve through the long hole of the control valve seat. The T-shaped pilot valve seat adopts a floating installation structure: the large end of the T-shaped control valve seat faces downwards, and the long column of the T-shaped pilot valve seat is slidably assembled in the central hole of the injector body. The large end of the T-shaped control valve seat and the central hole of the injector body have mutually mating sealing surfaces. The hydraulic pressure at the lower end of the T-shaped control valve seat causes the sealing surface of the T-shaped control valve seat to press against the sealing surface on the injector body. No needle valve spring is installed at the tail of the needle valve. When the engine stops or just starts, the control valve spring also acts as a needle valve preload spring, causing the needle valve to close. When the control valve is closed, the pressure at the tail of the needle valve is higher than the pressure at the front end of the needle valve, and the needle valve closes due to the pressure difference.
[0005] While this technical solution has its advantages, most needle-valve-less preloaded spring diesel injectors still have some shortcomings in practical use. For example, their inlet pipe joints lack corresponding filter components, preventing filtration and allowing impurities to enter with the fuel, thus affecting the service life of the diesel engine. Furthermore, some inlet pipe joints do have filter components, but these components are assembled using complex methods, such as screw connections, making installation and removal cumbersome and hindering filter replacement. Therefore, we propose the needle-valve-less preloaded spring diesel injector. Utility Model Content
[0006] The purpose of this invention is to provide a needle valve-free preload spring diesel injector to solve the defects mentioned in the background art.
[0007] To achieve the above objectives, this utility model provides the following technical solution:
[0008] A needle valve-less preloaded spring diesel injector includes a diesel injector body and an inlet pipe connector disposed on the diesel injector body. An oil passage is provided inside the inlet pipe connector. An inner limiting ring is fixedly installed on the rear end wall of the oil passage. The inner limiting ring has an annular structure. An inner filter element is inserted into the oil passage. An oil channel is provided inside the inner filter element, extending along the length of the inner filter element. A central mesh reinforcement cylinder is fixedly installed on the inner wall of the oil channel. Oil filter screens are fixedly installed on both ends of the central mesh reinforcement cylinder.
[0009] Preferably, a fluid passage hole connected to the oil passage is provided at the center of the inner limiting ring, and the fluid passage hole is arranged along the length of the oil passage.
[0010] Preferably, the liquid passage is frustum-shaped, and the inner diameter of the liquid passage increases sequentially from left to right;
[0011] This setting enables pressure relief protection, preventing excessive oil pressure at the inner limit ring from causing the rear pipeline to burst.
[0012] Preferably, the inner filter element abuts against the front side of the inner limiting ring, and the central mesh reinforcing cylinder has a mesh structure.
[0013] Preferably, both the central mesh reinforcing cylinder and the oil filter screen are wavy, and the end of the oil filter screen is simultaneously fixedly installed on the inner wall of the oil channel.
[0014] This setting increases the filtration area of the oil filter screen and also ensures that the structure of the oil filter screen is more robust and stable.
[0015] Preferably, a front-expanding oral cavity is provided at the front opening of the oil passage, and an outer-expanding oral cavity is provided on the front wall of the front-expanding oral cavity.
[0016] Preferably, the front end of the inner filter cartridge is located in the anterior expansion oral cavity, and the length of the inner filter cartridge located in the anterior expansion oral cavity is between 0.6cm and 1.3cm.
[0017] Preferably, an anti-slip layer is provided on the surface of the inner filter cartridge located in the anterior expansion chamber of the oral cavity, and the anti-slip layer is an anti-slip particle structure.
[0018] The above two features make it easier to clamp and remove the inner filter cartridge using tweezers or other tools for replacement in the anterior oral cavity.
[0019] Compared with the prior art, the beneficial effects of this utility model are:
[0020] 1. This utility model achieves the filtration of impurities in the diesel injector by setting an inner limiting ring and an inner filter element cylinder in the oil passage of the oil inlet pipe joint. The central mesh reinforcement cylinder in the inner filter element cylinder forms a filtration structure with the oil filter screen, thereby effectively preventing impurities from entering the diesel engine with the oil and achieving the effect of protecting the engine and extending its service life.
[0021] 2. This utility model designs the fluid passage as a frustum shape with an increasing inner diameter from left to right, and sets it in the front expansion chamber and the outer expansion chamber on the front side. This achieves pressure relief protection for the oil, avoids excessive oil pressure at the inner limit ring, which could cause the rear pipe to burst, and ensures the safe and stable operation of the injector oil circuit system.
[0022] 3. This utility model increases the filtration area of the oil filter by designing the central mesh reinforcement cylinder and the oil filter screen in a wavy shape, and by setting an anti-slip layer on the end of the inner filter element cylinder located in the front expansion chamber. This ensures that the structure is firm and stable. At the same time, the inner filter element cylinder and the oil passage are connected by an insertion joint, which makes it easy to use tools such as tweezers to clamp the inner filter element cylinder for replacement, making replacement more convenient. This achieves the effect of improving filtration efficiency and facilitating maintenance. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0024] Figure 2 This utility model Figure 1 Enlarged view of point A in the middle;
[0025] Figure 3 This is a schematic diagram of the inner limiting ring of this utility model;
[0026] Figure 4This is a schematic diagram of the structure of the inner filter element cylinder of this utility model;
[0027] The meanings of the labels in the diagram are as follows:
[0028] 1. Diesel injector body; 10. Inlet pipe connector; 11. Oil passage; 12. Inner limiting ring; 121. Fluid passage hole; 13. Front expansion chamber; 14. Outer expansion chamber;
[0029] 2. Inner filter element; 20. Oil channel; 21. Central mesh reinforcement cylinder; 22. Oil filter screen; 23. End anti-slip layer. Detailed Implementation
[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0031] Please see Figures 1-4 This utility model provides a technical solution: a needle valve-free preload spring diesel injector, including a diesel injector body 1 and an inlet pipe connector 10 disposed on the diesel injector body 1. An oil passage 11 is provided inside the inlet pipe connector 10. An inner limiting ring 12 is fixedly installed on the rear end cavity wall of the oil passage 11. The inner limiting ring 12 has an annular structure. An inner filter element cylinder 2 is inserted and fitted inside the oil passage 11. An oil channel 20 is provided inside the inner filter element cylinder 2 along the length direction of the inner filter element cylinder 2. A central mesh reinforcement cylinder is fixedly installed on the inner wall of the oil channel 20. 21. Oil filters 22 are fixedly installed on both ends of the central mesh reinforcement cylinder 21, so that the oil passes through the inner filter cylinder 2 before entering the diesel injector body 1. The central mesh reinforcement cylinder 21 and the oil filter 22 effectively intercept impurities, prevent impurities from entering the injector, ensure the cleanliness of the fuel, make the injector work more stably, and extend the service life of the injector and the engine. In addition, the inner filter cylinder 2 is inserted into the oil passage 11, and the inner filter cylinder 2 abuts against the front side of the inner limit ring 12, which facilitates the disassembly and replacement of the inner filter cylinder 2.
[0032] In this embodiment, a fluid passage hole 121 connected to the oil passage 11 is provided at the center of the inner limiting ring 12. The fluid passage hole 121 is arranged along the length of the oil passage 11. The fluid passage hole 121 is frustum-shaped, and the inner diameter of the fluid passage hole 121 increases from left to right. When the oil flows through the fluid passage hole 121, its special shape makes the oil flow space gradually larger, the flow velocity decreases, and the pressure is buffered. This effectively avoids the risk of the rear pipe bursting due to excessive oil pressure at the inner limiting ring 12, and enhances the safety and reliability of the oil circuit system of the oil inlet pipe joint 10.
[0033] like Figure 2 As shown, the central mesh reinforcing cylinder 21 has a mesh structure, and the inner filter element cylinder 2 abuts against the inner limiting ring 12 to form a stable support, ensuring that the position of the inner filter element cylinder 2 is fixed during the filtration process; the mesh-shaped central mesh reinforcing cylinder 21 provides support for the oil filter screen 22 while ensuring the smooth passage of oil, ensuring the stability of the filtration structure and ensuring the normal realization of the filtration function.
[0034] like Figure 2 As shown, both the central mesh reinforcement cylinder 21 and the oil filter screen 22 are wavy. The ends of the oil filter screen 22 are fixedly installed on the inner wall of the oil channel 20. The wavy structure greatly increases the contact area between the oil filter screen 22 and the oil, significantly improving the filtration efficiency. At the same time, this structure enhances the structural strength of the oil filter screen 22, making it less prone to deformation and damage during the filtration process, thus ensuring a long-term stable filtration effect.
[0035] like Figure 2 As shown, a front expansion chamber 13 is provided at the front opening of the oil passage 11, and an outer expansion chamber 14 is provided on the front wall of the front expansion chamber 13. The front expansion chamber 13 provides a larger operating space for the installation and removal of the inner filter element 2, and the outer expansion chamber 14 can further optimize the flow state of the oil entering the oil passage 11, reduce the oil flow resistance, make the oil flow smoother, and ensure the stability of the oil intake of the injector.
[0036] like Figure 2 As shown, the front end of the inner filter cartridge 2 is located in the anterior expansion chamber 13. The length of the inner filter cartridge 2 located in the anterior expansion chamber 13 is between 0.6cm and 1.3cm. The appropriate length allows the front end of the inner filter cartridge 2 to protrude from the oil passage 11, making it convenient for operators to use tools such as tweezers to clamp and operate. At the same time, it ensures that the inner filter cartridge 2 has sufficient installation depth in the oil passage 11 to ensure the effectiveness of the filtration function.
[0037] It is worth noting that the inner filter cartridge 2 located in the anterior expansion chamber 13 is provided with an end anti-slip layer 23. The end anti-slip layer 23 has an anti-slip particle structure. The anti-slip particles increase the friction of the inner filter cartridge 2 surface. When using tools such as tweezers to hold the inner filter cartridge 2 for replacement, it can effectively prevent the inner filter cartridge 2 from slipping, making the replacement process smoother and more convenient, and improving the efficiency of maintenance.
[0038] When using the needleless valve preloaded spring diesel injector of this utility model, the inner filter element cylinder 2 is installed in the oil passage 11 of the oil inlet pipe joint 10 by plugging and connecting, so that its front end abuts against the front side of the inner limiting ring 12. The central mesh reinforcement cylinder 21 inside the inner filter element cylinder 2 and the oil filter screen 22 form a filter structure.
[0039] When the engine is running, high-pressure fuel enters the oil passage 11 from the fuel inlet pipe joint 10. It is first filtered by the inner filter element 2. The fuel passes through the fuel passage 20, and impurities are intercepted by the central mesh reinforcement cylinder 21 and the fuel filter screen 22. Then, the fuel flows through the frustum-shaped liquid passage 121 in the center of the inner limiting ring 12. After the pressure is buffered, it smoothly enters the fuel passage of the diesel injector body 1 to participate in the subsequent injection process.
[0040] When the inner filter cartridge 2 needs to be replaced, the operator can use the operating space reserved in the front expansion chamber 13 to use tweezers or other tools to grasp the inner filter cartridge 2, which is of appropriate length and has an anti-slip layer 23 on the end of the front expansion chamber 13, and easily remove it. When replacing the new inner filter cartridge 2, the operator can also use the same space and structural features to accurately insert the new filter cartridge into the oil passage 11 and press it against the inner limit ring 12 to complete the replacement and ensure that the injector continues to work stably.
[0041] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.
Claims
1. A needle valve-less preloaded spring diesel injector, comprising a diesel injector body (1) and an inlet pipe connector (10) disposed on the diesel injector body (1), characterized in that: An oil passage (11) is provided inside the oil inlet pipe joint (10). An inner limiting ring (12) is fixedly installed on the rear end cavity wall of the oil passage (11). The inner limiting ring (12) is a ring structure. An inner filter element cylinder (2) is inserted and fitted inside the oil passage (11). An oil channel (20) is provided inside the inner filter element cylinder (2) along the length direction of the inner filter element cylinder (2). A central mesh reinforcement cylinder (21) is fixedly installed on the inner wall of the oil channel (20). An oil filter screen (22) is fixedly installed on both ends of the central mesh reinforcement cylinder (21).
2. The needle-free preloaded spring diesel injector according to claim 1, characterized in that: The inner limiting ring (12) is provided with a fluid passage hole (121) connected to the oil passage (11) at the center position, and the fluid passage hole (121) is arranged along the length direction of the oil passage (11).
3. The needleless valve preloaded spring diesel injector according to claim 2, characterized in that: The liquid passage (121) is frustum-shaped, and the inner diameter of the liquid passage (121) increases sequentially from left to right.
4. The needle-free preloaded spring diesel injector according to claim 1, characterized in that: The inner filter element (2) rests against the front side of the inner limiting ring (12), and the central mesh reinforcement cylinder (21) has a mesh structure.
5. The needle-free preload spring diesel injector according to claim 1, characterized in that: Both the central mesh reinforcement cylinder (21) and the oil filter (22) are wavy, and the end of the oil filter (22) is fixedly installed on the inner wall of the oil channel (20).
6. The needleless valve preloaded spring diesel injector according to claim 1, characterized in that: An anteriorly expanded oral cavity chamber (13) is provided at the front opening of the oil passage (11), and an laterally expanded oral cavity chamber (14) is provided on the front wall of the anteriorly expanded oral cavity chamber (13).
7. The needleless valve preloaded spring diesel injector according to claim 6, characterized in that: The front end of the inner filter cartridge (2) is located in the anterior expansion oral cavity (13), and the length of the inner filter cartridge (2) located in the anterior expansion oral cavity (13) is between 0.6cm and 1.3cm.
8. The needleless valve preloaded spring diesel injector according to claim 7, characterized in that: An anti-slip layer (23) is provided on the surface of the inner filter cartridge (2) located in the anterior expansion oral cavity (13), and the anti-slip layer (23) is an anti-slip particle structure.