Marine fuel injector safety valve

Abstract

The utility model discloses a marine fuel injector safety valve which comprises a valve body applied to a fuel injector, the valve body is provided with a hollow valve cavity, a valve element is arranged in the valve cavity, and a pressure mechanism capable of driving the valve element to move downwards is arranged at the top of the valve element. The pressure mechanism comprises an adjusting part, a pressing plate and a double-layer spiral spring, a deformation space used for installing the double-layer spiral spring is defined between the pressing plate and the valve element, and the resilience force of the double-layer spiral spring is used for driving the valve element to block the opening in the bottom of the valve cavity. An oil inlet channel communicated with the bottom of the valve cavity is arranged at the bottom of the valve body, and the oil inlet channel is of a spiral structure. According to the technical scheme provided by the utility model, the double-layer reducing reverse spiral spring is innovatively adopted and is matched with the design of the spiral oil inlet channel, so that a hydraulic damping effect is generated in the rapid opening and closing process, transient response is ensured, and mechanical oscillation is inhibited.

Description

Technical Field

[0001] This utility model belongs to the field of safety valve technology, specifically a marine fuel injector safety valve. Background Technology

[0002] The manufacturing technology of marine medium- and high-speed high-power diesel engines is extremely complex. Among them, the core component technology, represented by the high-pressure common rail electronic fuel injection system, is particularly crucial. Not only are high performance requirements demanded, but safety and reliability must also be guaranteed. Currently, in order to ensure the safe operation of the high-pressure common rail electronic fuel injection system, a safety valve is added to the injector in the injection system to perform a pressure relief operation when the fuel pressure is too high.

[0003] Current safety valves generally use springs to actuate the seals, resulting in a fixed sealing pressure. Traditional marine injector safety valves suffer from the following drawbacks: 1) Springs are susceptible to vibration and displacement, causing set pressure drift; 2) High pressure during depressurization leads to cavitation damage to the sealing surface due to the impact of high-pressure oil; 3) Water hammer during depressurization exacerbates valve vibration. Therefore, a new marine injector safety valve is proposed. Utility Model Content

[0004] The purpose of this utility model is to provide a safety valve for marine fuel injectors in order to solve the problems mentioned above.

[0005] The technical solution adopted by this utility model is as follows: A marine injector safety valve includes a valve body applied to the injector, the valve body having a hollow valve cavity, a valve core being disposed inside the valve cavity, and a pressure mechanism being disposed on the top of the valve core that can drive it to move downward; the pressure mechanism includes an adjusting component, a pressure plate, and a double-layer helical spring, the pressure plate and the valve core forming a deformation space for installing the double-layer helical spring, and the rebound force of the double-layer helical spring being used to drive the valve core to seal the bottom opening of the valve cavity.

[0006] In a preferred embodiment, the bottom of the valve body is provided with an oil inlet channel that communicates with the bottom of the valve cavity, and the oil inlet channel is arranged in a spiral structure.

[0007] In a preferred embodiment, the valve body has a connecting joint on its side that communicates with the side of the valve cavity, and the oil outlet end of the connecting joint is connected to an external oil return system.

[0008] In a preferred embodiment, the double-layer helical spring includes an inner helical spring and an outer helical spring arranged sequentially from the inside to the outside, and the helical directions of the inner and outer helical springs are opposite.

[0009] In a preferred embodiment, the adjusting member is a screw, which is threadedly connected to the top wall of the valve body, and the bottom of the adjusting member extends into the valve body and abuts against the pressure plate.

[0010] In a preferred embodiment, the outer wall of the valve core is recessed inward to form an annular groove, and a sealing ring is embedded in the annular groove. The outer wall of the sealing ring is elastically fitted to the inner wall of the valve cavity.

[0011] In a preferred embodiment, the outer diameter of the valve core is the same as the inner diameter of the valve cavity, and the length of the valve core is greater than the length of the valve cavity.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0013] 1. In this utility model, a double-layer variable diameter reverse helical spring is used instead of the traditional single spring structure. The double reverse helical structure can suppress resonance, reduce the amplitude under high frequency vibration, and avoid the problem of accidental opening. It is suitable for vibration reduction scenarios. Moreover, the double-layer reverse structure shares the dynamic load, reduces the local wear of the single-layer spring, and delays fatigue aging.

[0014] 2. In this utility model, the valve body is configured with a spiral-shaped oil inlet channel, which generates a hydraulic damping effect during rapid opening and closing, ensuring both transient response and suppressing mechanical oscillation. Attached Figure Description

[0015] Figure 1 This is a cross-sectional planar structural diagram of the entire utility model;

[0016] Figure 2 This is a simplified three-dimensional structural diagram of the double-layer helical spring in this utility model.

[0017] The markings in the diagram are: 1-valve body, 100-valve cavity, 2-valve core, 3-sealing ring, 4-oil inlet channel, 5-connecting joint, 6-pressure plate, 7-double-layer helical spring, 71-outer helical spring, 72-inner helical spring, 8-adjusting component. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0019] Reference Figure 1-2A marine fuel injector safety valve includes a valve body 1 applied to the fuel injector. The valve body 1 has a hollow valve cavity 100, and a valve core 2 is disposed inside the valve cavity 100. A pressure mechanism is disposed on the top of the valve core 2, which can be driven to move downward. The pressure mechanism includes an adjusting element 8, a pressure plate 6, and a double-layer helical spring 7. The pressure plate 6 and the valve core 2 form a deformation space for installing the double-layer helical spring 7. The rebound force of the double-layer helical spring 7 is used to drive the valve core 2 to block the bottom opening of the valve cavity 100. The double-layer helical spring 7 includes an inner helical spring 72 and an outer helical spring 71 arranged sequentially from the inside to the outside. The spiral directions of 71 are set in opposite directions. A double-layer variable diameter reverse spiral spring is used instead of the traditional single spring structure. The double-layer spiral spring 7 can suppress resonance, reduce the amplitude under high frequency vibration, and avoid the problem of accidental opening. It is suitable for vibration damping scenarios (i.e., marine common rail engines). Moreover, the double-layer reverse structure shares the dynamic load, reduces the local wear of the single-layer spring, and delays fatigue aging. The inner and outer spiral directions are opposite (one layer is left-handed and one layer is right-handed). The torque generated when under force cancels each other out, reduces overall torsion and lateral sway, and avoids instability caused by unidirectional torsion. Therefore, it is not easy to cause wear on the valve core 2, the inner wall of the valve cavity 100 and the seals.

[0020] Furthermore, the bottom of the valve body 1 is provided with an oil inlet channel 4 that communicates with the bottom of the valve cavity 100. The oil inlet channel 4 is arranged in a spiral structure. The oil inlet channel 4 inside the valve body 1 is arranged in a spiral shape, which generates a hydraulic damping effect during rapid opening and closing, which not only ensures transient response but also suppresses mechanical oscillation. In addition, it can also work together to improve flow stability and reduce eddies and turbulence.

[0021] Furthermore, the valve body 1 is provided with a connecting joint 5 on its side, which is connected to the side of the valve cavity 100. The oil outlet of the connecting joint 5 is connected to the external oil return system. When the injector nozzle is blocked, the high pressure of the system rises abnormally. If the pressure is higher than the opening pressure of the safety valve, it will squeeze the valve core 2 and the double-layer helical spring 7 to move upward. At this time, the safety valve opens, and the high-pressure fuel flows back to the external oil return system (not shown in the figure) through the designed oil circuit, so as to reduce the pressure and ensure the normal operation of the system. The external oil return system includes pipelines, low-pressure oil tanks and other structures.

[0022] Furthermore, the adjusting element 8 is a screw, which is threaded onto the top wall of the valve body 1. The bottom of the adjusting element 8 extends into the valve body 1 and abuts against the pressure plate 6. The depth of the screw is adjusted according to the desired opening pressure. The more it is fed in, the greater the subsequent opening pressure (i.e., the change in the spring force after compression), and vice versa. It can be adjusted according to actual needs.

[0023] Furthermore, the outer diameter of the valve core 2 is the same as the inner diameter of the valve cavity 100, the length of the valve core 2 is greater than the length of the valve cavity 100, the outer wall of the valve core 2 is recessed inward to form an annular groove, and a sealing ring 3 is embedded in the annular groove. The outer wall of the sealing ring 3 is elastically fitted with the inner wall of the valve cavity 100. The sealing performance at the connection between the valve cavity 100 and the valve core 2 can be improved by the sealing ring 3.

[0024] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A safety valve for a marine fuel injector, characterized in that, The device includes a valve body for use on a fuel injector, the valve body having a hollow valve cavity, a valve core disposed inside the valve cavity, and a pressure mechanism disposed on the top of the valve core that can drive it to move downward; the pressure mechanism includes an adjusting element, a pressure plate, and a double-layer helical spring, the pressure plate and the valve core forming a deformation space for mounting the double-layer helical spring, the rebound force of the double-layer helical spring being used to drive the valve core to seal the bottom opening of the valve cavity.

2. The marine injector safety valve as described in claim 1, characterized in that: The bottom of the valve body is provided with an oil inlet channel that communicates with the bottom of the valve cavity, and the oil inlet channel is arranged in a spiral structure.

3. A marine fuel injector safety valve as described in claim 1, characterized in that: The valve body has a connecting joint on its side that communicates with the side of the valve cavity, and the oil outlet end of the connecting joint is connected to the external oil return system.

4. A marine fuel injector safety valve as described in claim 1, characterized in that: The double-layer helical spring includes an inner helical spring and an outer helical spring arranged sequentially from the inside to the outside, and the helical directions of the inner and outer helical springs are opposite.

5. A marine fuel injector safety valve as described in claim 1, characterized in that: The adjusting component is a screw, which is threaded to the top wall of the valve body. The bottom of the adjusting component extends into the valve body and abuts against the pressure plate.

6. A marine fuel injector safety valve as described in claim 1, characterized in that: The outer wall of the valve core is recessed inward to form an annular groove, and a sealing ring is embedded in the annular groove. The outer wall of the sealing ring is elastically fitted to the inner wall of the valve cavity.

7. A marine fuel injector safety valve as described in claim 1, characterized in that: The outer diameter of the valve core is the same as the inner diameter of the valve cavity, and the length of the valve core is greater than the length of the valve cavity.

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