A leakage-proof device for the connection between a diesel engine injector and a high-pressure oil pipe

Abstract

The application relates to a leakage-proof device for the connection between a diesel engine injector and a high-pressure oil pipe, comprising an improved lower-positioned injector with a pressure regulating spring, a front end of the injector being provided with threads matched with a tightly-pressed hollow bolt, and a rear end of the injector being provided with an installation space matched with an O-shaped sealing ring on the tightly-pressed hollow bolt. The application solves the problem of diesel oil leakage at the threaded joint between the injector and the high-pressure oil pipe without changing the original appearance and installation size of the injector, and moves the oil inlet of the injector forward to provide an installation position for the O-shaped sealing ring under the premise of ensuring the performance of the injector, so that the O-shaped sealing ring can complete the oil sealing task, and the application can be widely applied to the leakage-proof between the diesel engine injector and the high-pressure oil pipe.

Description

Technical Field

[0001] This application relates to the field of anti-leakage technology for diesel engine fuel supply systems, and in particular to an anti-leakage device for the connection between a diesel engine injector and a high-pressure fuel line. Background Technology

[0002] A certain type of diesel engine exhibited symptoms such as rising oil level in the tank, decreased power, and abnormal noises during operation. Analysis revealed that the abnormal operation was caused by diesel fuel mixing with the engine oil. This caused the oil level to rise, and the diesel diluted the oil, reducing its viscosity and preventing the formation of an effective lubricating film on the friction surfaces. This resulted in increased wear on the friction surfaces and irregular metallic knocking sounds. Further investigation revealed that the key to these problems lay in the diesel engine's injectors and high-pressure fuel lines. These injectors and high-pressure fuel lines, connected and secured by threads, supply high-pressure fuel to the engine. Under the impact of the high-pressure fuel pulsations, the threads at their connection points, subjected to high-frequency impacts from the fuel and engine vibrations, caused diesel fuel leakage. Since the injectors are mounted on the cylinder head, this leaked diesel fuel directly entered the valve cover, easily leading to diesel-fuel mixing. Meanwhile, due to poor thread sealing, outside air can be drawn into the fuel line and then into the fuel injection pump, causing the engine to fail to start or to shut down automatically.

[0003] In view of this, this application aims to develop a leak-proof device for the connection between the diesel engine injector and the high-pressure fuel line, which solves the problems of diesel-fuel mixing and automatic engine shutdown without altering the overall structure of the diesel engine as much as possible. Summary of the Invention

[0004] The technical problem to be solved by this application is that during the operation of a diesel engine, the oil level in the oil tank rises, the power decreases, and abnormal noises occur due to diesel fuel mixing with the engine oil.

[0005] To solve the above-mentioned technical problems, this application provides a leak-proof device for the connection between a diesel engine injector and a high-pressure fuel line, comprising: an injector with a lower-mounted pressure regulating spring inside, one end of the oil inlet channel and the oil return channel extending upwards towards the pressure regulating spring; a high-pressure fuel line with a clamping hollow bolt at the connection section with the injector, an O-ring being installed at one end of the clamping hollow bolt near the injector; a nut at the other end of the clamping hollow bolt for locking the clamping hollow bolt; wherein, the front end of the injector has a thread that mates with the clamping hollow bolt, and a conical surface for conical sealing, and the rear end of the thread has reserved installation space to mate with the O-ring on the clamping hollow bolt.

[0006] According to an embodiment of this application, the compacted hollow bolt is 14 mm longer than a conventional compacted hollow bolt.

[0007] According to an embodiment of this application, the O-ring has a specification of φ13.2×φ1.8.

[0008] According to an embodiment of this application, the installation space reserved at the rear end of the thread forms an O-ring seat, and the specifications of the O-ring seat are φ13.2×φ1.8.

[0009] According to an embodiment of this application, the nut is an M16×1.5 anti-loosening nut added to the tail of the hollow bolt.

[0010] According to an embodiment of this application, the high-pressure oil pipe connects the oil inlet channel and the oil return channel.

[0011] According to an embodiment of this application, an O-ring is installed in the slot of a clamping hollow bolt for sealing low-pressure diesel fuel.

[0012] According to the embodiments of this application, the conical surface of the compressed hollow bolt and the injector is free from indentations, wear or foreign matter, and the contact area of ​​the conical surface is uniform without uneven wear.

[0013] According to an embodiment of this application, the injector and the high-pressure oil pipe are connected by threads, the connecting thread of the injector is moved forward, and space is reserved at the rear end of the connecting thread for an O-ring seal.

[0014] According to embodiments of this application, the leak-proof device is used to isolate and seal low-pressure leaking diesel fuel with a pressure of 0.25~0.55MPa, preventing it from leaking outward from the threaded joint.

[0015] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0016] 1. This application solves the problem of diesel leakage at the joint between the injector and the high-pressure oil pipe thread by using a combination of extended hollow bolts, O-rings, and a lower spring, as well as a double seal of conical surface and O-ring, without changing the original injector's external shape and installation dimensions.

[0017] 2. The original injector was a top-mounted pressure regulating spring type, which could not provide installation space for the new O-ring. This application improves it to a bottom-mounted pressure regulating spring type, and moves the oil inlet and connecting thread forward. Without changing the external installation dimensions, it reserves an installation position for the O-ring, enabling the O-ring to complete the oil sealing task and achieving compatibility of sealing functions. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this application, and are not intended to limit this application.

[0019] Figure 1 This is a schematic diagram illustrating the connection between the injector and the high-pressure fuel line, as exemplified by the present invention.

[0020] Figure 2 This is a schematic diagram comparing the original injector and the improved injector as examples of the present invention.

[0021] The annotations in the attached figures are explained as follows:

[0022] 10. High-pressure oil pipe, 11. Tightening hollow bolt, 12. Nut, 13. O-ring seal, 20. Injector, 21. Oil inlet channel, 22. Oil return channel, 23. Pressure regulating spring, 111. Slot.

[0023] Where A is the original injector and B is the improved injector. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the described embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this application pertains. The terms “first,” “second,” and similar terms used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a,” and similar terms, do not indicate a limitation of quantity, but rather indicate the presence of at least one.

[0026] like Figure 1 , Figure 2 As shown in the example, this application provides a leak-proof device for the connection between a diesel engine injector and a high-pressure fuel line. It includes an improved pressure regulating spring 23 and a lower-mounted injector 20. The injector 20 has a thread at its front end that mates with a tightening hollow bolt 11, and an installation space at its rear end that mates with an O-ring seal 13 on the tightening hollow bolt 11. This application solves the problem of diesel leakage at the threaded connection between the injector 20 and the high-pressure fuel line 10 without altering the original injector's external dimensions. While ensuring the performance of the injector 20, the injector 20's fuel inlet is moved forward, providing an installation position for the O-ring seal 13, allowing the O-ring seal 13 to perform its sealing function.

[0027] In this embodiment, a lower-mounted pressure regulating spring 23 is provided inside the injector 20, and one end of the oil inlet channel 21 and the oil return channel 22 extends above the pressure regulating spring 23.

[0028] Specifically, because an O-ring 13 was added to the tightening hollow bolt 11, the original injector lacked a mating position with the O-ring 13, thus failing to prevent diesel fuel leakage using the O-ring 13. Therefore, the original injector design was improved. Figure 2 As shown, the original pressure regulating spring 23 upper-mounted injector is changed to a pressure regulating spring 23 lower-mounted injector. The oil inlet of injector 20 is moved forward, and the corresponding connection thread between high-pressure oil pipe 10 and injector 20 is also arranged forward. Without changing the original external shape and installation dimensions of injector 20, the O-ring seal 13 added to high-pressure oil pipe 10 is positioned at the rear end of the connection thread between injector 20 and high-pressure oil pipe 10, thereby ensuring that the O-ring seal 13 performs the function of engine-diesel isolation and sealing during diesel engine operation.

[0029] In this embodiment, the high-pressure oil pipe 10 is provided with a clamping hollow bolt 11 at the connection section with the injector 20. An O-ring is installed at one end of the clamping hollow bolt 11 near the injector 20. A nut 12 is provided at the other end of the clamping hollow bolt 11 for locking the clamping hollow bolt 11.

[0030] The injector 20 has a thread at the front end that mates with the tightening hollow bolt 11, and a conical surface for conical sealing. The rear end of the thread has reserved installation space to mate with the O-ring 13 on the tightening hollow bolt 11.

[0031] Specifically, the tightening hollow bolt 11 is 14mm longer than the traditional tightening hollow bolt 11. To address the low-pressure oil leakage issue, the high-pressure oil pipe 10 is redesigned by extending the tightening hollow bolt 11 of the high-pressure oil pipe 10 by 14mm and adding a φ13.2×φ1.8 O-ring seal. At the same time, an M16x1.5 loosening nut is added to the tail of the tightening hollow bolt 11 to enhance the sealing effect between the conical surface of the high-pressure oil pipe and the conical surface of the injector 20.

[0032] Specifically, the O-ring has a specification of φ13.2×φ1.8. Meanwhile, the installation space reserved at the rear end of the thread forms an O-ring seat, with a corresponding specification of φ13.2×φ1.8.

[0033] Specifically, nut 12 is an M16×1.5 anti-loosening nut added to the tail of the hollow bolt 11 to tighten it.

[0034] Specifically, the high-pressure oil pipe 10 connects the oil inlet channel 21 and the oil return channel 22.

[0035] Specifically, the O-ring 13 is installed in the slot 111 of the tightening hollow bolt 11 for sealing low-pressure diesel fuel.

[0036] Specifically, the conical surface of the tightened hollow bolt 11 and the injector 20 is free of indentations, wear, or foreign matter, and the contact area of ​​the conical surface is uniform without uneven wear.

[0037] Specifically, the injector 20 and the high-pressure oil pipe 10 are connected by threads. The connection thread of the injector 20 is moved forward, and space is reserved at the rear end of the connection thread for the O-ring seal 13.

[0038] Specifically, the leak-proof device is used to isolate and seal low-pressure leaking diesel fuel with a pressure of 0.25~0.55MPa, preventing it from leaking outward from the threaded joint.

[0039] The working principle of the anti-leakage device for the connection between the diesel engine injector and the high-pressure fuel line in this embodiment is as follows: the tight-fitting hollow bolt 11 of the high-pressure fuel line 10 and the conical surface of the injector 20 are tightly fitted by the pre-tightening force of the nut 12. This structure is mainly used to seal fuel with extremely high pressure (usually at the level of hundreds of MPa) to prevent high-pressure fuel leakage. When the tight-fitting hollow bolt 11 is tightened with the threads of the injector 20, the O-ring seal 13 on the tight-fitting hollow bolt 11 will be embedded in the reserved installation position of the injector 20. This structure is specifically used to isolate and seal low-pressure leaking diesel fuel with a pressure of 0.25~0.55MPa, preventing it from leaking outward from the threaded connection. The M16×1.5 at the tail can prevent the tight-fitting hollow bolt 11 from loosening under diesel engine vibration conditions, which ensures the long-term effectiveness of the conical surface seal and the O-ring seal.

[0040] In summary, the technical solution of this application has the following beneficial effects:

[0041] 1. This application solves the problem of diesel leakage at the joint between the injector and the high-pressure oil pipe thread by using a combination of extended hollow bolts, O-rings, and a lower spring, as well as a double seal of conical surface and O-ring, without changing the original injector's external shape and installation dimensions.

[0042] 2. The original injector was a top-mounted pressure regulating spring type, which could not provide installation space for the new O-ring. This application improves it to a bottom-mounted pressure regulating spring type, and moves the oil inlet and connecting thread forward. Without changing the external installation dimensions, it reserves an installation position for the O-ring, enabling the O-ring to complete the oil sealing task and achieving compatibility of sealing functions.

[0043] The above are merely exemplary embodiments of this application and are not intended to limit the scope of protection of this application, which is determined by the appended claims.

Claims

1. A leak-proof device for the connection between a diesel engine injector and a high-pressure fuel line, characterized in that, include: The injector has a lower-mounted pressure regulating spring inside, and one end of the oil inlet channel and the oil return channel extends upward to the pressure regulating spring; The high-pressure oil pipe is connected to the injector with a clamping hollow bolt. An O-ring is installed at one end of the clamping hollow bolt near the injector. A nut is provided at the other end of the clamping hollow bolt for locking the clamping hollow bolt. The injector has a thread at its front end that mates with a tightening hollow bolt, and a conical surface for conical sealing. The rear end of the thread has reserved installation space to mate with the O-ring on the tightening hollow bolt.

2. A leak-proof device for the connection between a diesel engine injector and a high-pressure fuel line according to claim 1, characterized in that, The tightened hollow bolt is 14mm longer than the traditional tightened hollow bolt.

3. A leak-proof device for the connection between a diesel engine injector and a high-pressure fuel line according to claim 1, characterized in that, The O-ring has a specification of φ13.2×φ1.

8.

4. A leak-proof device for the connection between a diesel engine injector and a high-pressure fuel line according to claim 3, characterized in that, The installation space reserved at the rear end of the thread forms an O-ring seat, and the specifications of the O-ring seat are φ13.2×φ1.

8.

5. A leak-proof device for the connection between a diesel engine injector and a high-pressure fuel line according to claim 1, characterized in that, The nut is an M16×1.5 anti-loosening nut added to the tail of the tightening hollow bolt.

6. A leak-proof device for the connection between a diesel engine injector and a high-pressure fuel line according to claim 1, characterized in that, The high-pressure oil pipe connects the oil inlet channel and the oil return channel.

7. A leak-proof device for the connection between a diesel engine injector and a high-pressure fuel line according to claim 1, characterized in that, The O-ring is installed in the slot of the tightening hollow bolt for sealing low-pressure diesel fuel.

8. A leak-proof device for the connection between a diesel engine injector and a high-pressure fuel line according to claim 1, characterized in that, The tightened hollow bolt and the conical surface of the injector are free from indentations, wear, or foreign matter, and the contact area of ​​the conical surface is uniform without uneven wear.

9. A leak-proof device for the connection between a diesel engine injector and a high-pressure fuel line according to claim 1, characterized in that, The injector is threaded to the high-pressure oil pipe. The connecting thread of the injector is moved forward, and space is reserved at the rear end of the connecting thread for the O-ring seal.

10. A leak-proof device for the connection between a diesel engine injector and a high-pressure fuel line according to claim 1, characterized in that, The leak-proof device is used to isolate and seal low-pressure leaking diesel fuel with a pressure of 0.25~0.55MPa, preventing it from leaking outward from the threaded joint.

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