A dynamically pressure-adjustable fuel injector and a fuel injection system thereof

Abstract

This invention discloses a dynamically adjustable fuel injector and its injection system, comprising an injector body, a spring seat push rod, an adjusting shim, a compression spring, a clamping nut, a needle valve limiter disc, and a nozzle. A high-pressure fuel inlet is provided at the upper end of the injector body. The spring seat push rod, adjusting shim, compression spring, needle valve limiter disc, and nozzle are sequentially installed in the injector body from top to bottom and are sealed by the clamping nut threaded onto the lower end of the outer surface of the injector body. A low-pressure fuel inlet is provided at the upper end of the outer surface of the injector body, and the low-pressure fuel inlet is connected to a channel located above the spring seat push rod. This dynamically adjustable fuel injector and its injection system can dynamically adjust the injection pressure, while simultaneously reducing the stiffness of the compression spring, extending its service life, and achieving a cooling effect on the injector, thus greatly improving the reliability of the injector.

Description

Technical Field

[0001] This invention relates to the field of internal combustion engine technology, specifically to a dynamically adjustable fuel injector and its injection system. Background Technology

[0002] The existing Chinese patent number CN222415042U discloses a double-nut locking pressure regulating injector, which consists of a needle valve assembly, a nozzle cap, a needle valve limit plate, a push rod, a pressure regulating spring, an injector body, a spring seat, a pressure regulating block, and a pressure regulating nut. This patent has the following defects: (1) It has many parts and a complex structure, which cannot achieve dynamic pressure regulation. Moreover, the pressure regulation process requires multiple adjustments, and the nut is prone to wear; (2) Since the pressure regulation process requires multiple adjustments, it affects the service life of the pressure regulating spring; (3) It does not have the function of cooling the injector and requires a separate cooling system, which increases the cost. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the existing defects and provide a dynamically adjustable injector and its injection system, which overcomes the shortcomings of the existing injector technology, such as low reliability, inability to dynamically adjust pressure and lack of self-cooling.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a dynamically adjustable fuel injector, comprising an injector body, a spring seat push rod, an adjusting shim, a compression spring, a clamping nut, a needle valve limit disc, and a nozzle. The upper end of the injector body is provided with a high-pressure fuel inlet. The spring seat push rod, adjusting shim, compression spring, needle valve limit disc, and nozzle are sequentially installed in the injector body from top to bottom, and are sealed by the clamping nut threadedly connected to the lower end of the outer side of the injector body. The upper end of the outer side of the injector body is provided with a low-pressure fuel inlet, which is connected to a channel provided above the spring seat push rod.

[0005] The low-pressure fuel inlet is used to receive fuel filtered by the fuel filter. As the rotational speed varies, the fuel pressure at the spring seat push rod varies, thereby achieving the purpose of dynamically adjusting the injection pressure.

[0006] As a preferred embodiment of the present invention, the lower end of the outer side of the injector body is provided with an oil return port, which is connected to the oil return passage located at the gap of the needle valve limit disc.

[0007] As a preferred embodiment of the present invention, the nozzle includes a needle valve body and a needle valve, wherein the needle valve is located within the needle valve body, and the amount of fuel injected is adjusted by the relative movement of the needle valve and the needle valve body.

[0008] As a preferred embodiment of the present invention, a slit filter element is provided in the injector body, the slit filter element being positioned corresponding to the high-pressure fuel inlet and used to filter the high-pressure fuel entering the injector body.

[0009] As a preferred embodiment of the present invention, the spring seat push rod is an integral structure of the spring seat and the long push rod.

[0010] In a preferred embodiment of the present invention, the needle valve body and the needle valve limit disc are connected by a positioning pin.

[0011] As a preferred embodiment of the present invention, an O-ring is provided between the contact surface of the clamping nut and the injector body.

[0012] A dynamically pressure-adjustable fuel injection system includes a fuel injector, a fuel-water separator, a manual pump, a low-pressure delivery pump, a fuel filter, a fuel injection pump, and a throttle valve;

[0013] The output pipeline of the oil-water separator is connected to the manual pump and the low-pressure delivery pump respectively. Both the manual pump and the low-pressure delivery pump are connected to the inlet of the fuel filter. The output pipeline of the fuel filter is divided into two paths: one path enters the low-pressure fuel inlet of the injector, and the other path enters the injection pump. The output end of the injection pump is connected to the high-pressure fuel inlet of the injector and the oil-water separator respectively.

[0014] A throttle valve is installed on the fuel filter and injector lines to regulate the pressure of the low-pressure fuel entering the injector.

[0015] As a preferred embodiment of the present invention, the oil return port on the injector is connected to the output pipeline of the oil-water separator via a pipeline.

[0016] As a preferred technical solution of the present invention, a one-way valve is provided on the output pipeline of the oil-water separator.

[0017] Compared with the prior art, the beneficial effects of the present invention are: (1) fewer parts, as the output pressure of the low-pressure delivery pump varies with different rotation speeds, the fuel pressure at the spring seat push rod also varies, and the preload of the pressure regulating spring varies, so the injection pressure can be dynamically adjusted; (2) the stiffness of the compression spring can be reduced, and the service life of the pressure regulating spring can be extended; (3) the low-pressure fuel leaks through the gap of the spring seat push rod, which can lubricate the mating surface and cool the injector at the same time, eliminating the need for a special cooling system and reducing costs. Attached Figure Description

[0018] Figure 1 This is a main sectional view of the present invention;

[0019] Figure 2 This is a cross-sectional view of the return oil passage of the present invention;

[0020] Figure 3 This is a schematic diagram illustrating the working principle of the fuel injection system.

[0021] In the diagram: 1 Injector body, 2 Slotted filter element, 3 Low-pressure fuel inlet, 4 Spring seat push rod, 5 Adjusting shim, 6 Compression spring, 7 Pressure nut, 8 Needle valve limit plate, 9 Nozzle, 91 Needle valve body, 92 Needle valve, 10 Positioning pin, 11 O-ring, 12 Return port, 13 High-pressure fuel inlet, K1 Injection pump, K2 Manual pump, K3 Low-pressure delivery pump, K4 Fuel filter, K5 Injection pump, K6 Injector, K7 Check valve, K8 Throttle valve. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments (for ease of description and understanding, the following refers to...). Figure 1 (The above is described above). Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0023] Please see Figure 1-2 The present invention provides a technical solution: a dynamically adjustable fuel injector, comprising an injector body 1, a spring seat push rod 4, an adjusting shim 5, a compression spring 6, a clamping nut 7, a needle valve limit disc 8, and a nozzle 9. The upper end of the injector body 1 is provided with a high-pressure oil inlet 13. The spring seat push rod 4, the adjusting shim 5, the compression spring 6, the needle valve limit disc 8, and the nozzle 9 are installed in the injector body 1 from top to bottom, and are sealed by the clamping nut 7 threadedly connected to the lower end of the outer side of the injector body 1.

[0024] The nozzle 9 includes a needle valve body 91 and a needle valve 92. The needle valve 92 is located inside the needle valve body 91, and the amount of fuel injected is adjusted by the relative movement of the needle valve 92 and the needle valve body 91.

[0025] A low-pressure fuel inlet 3 is provided on the upper part of the outer side of the injector body 1. The low-pressure fuel inlet 3 is connected to a channel located above the spring seat push rod 4. After being filtered, the low-pressure fuel enters the injector body 1 through the low-pressure fuel inlet 3. As the rotation speed is different, the fuel pressure at the spring seat push rod 4 is different. By controlling the pressure of the low-pressure fuel entering, the injection pressure can be dynamically adjusted. At the same time, the stiffness of the compression spring 6 can be reduced, and the service life of the compression spring 6 can be extended.

[0026] In this embodiment, since the low-pressure fuel is clean fuel, it can lubricate the mating surfaces and cool the fuel injector by leaking through the gap of the spring seat push rod 4.

[0027] In order to achieve the reuse of low-pressure fuel and save costs, a return port 12 is provided at the lower end of the outer side of the injector body 1. The return port 12 is connected to the return oil passage located at the gap of the needle valve limit plate 8. The low-pressure fuel rises along the gap of the needle valve limit plate 8 and flows out from the return oil passage.

[0028] Furthermore, in order to filter the high-pressure fuel, a slit filter element 2 is installed inside the injector body 1. The slit filter element 2 corresponds to the high-pressure fuel inlet 13 and is used to filter the high-pressure fuel entering the injector body 1.

[0029] In this embodiment, the existing spring seat push rod 4 is generally short. The spring seat push rod 4 is an integrated structure of spring seat and long push rod, which can enhance the stability of compression spring 6 and improve the reliability of injector.

[0030] Furthermore, in order to improve the connection stability of the needle valve body 91, the needle valve body 91 and the needle valve limit plate 8 are connected by a positioning pin 10.

[0031] Furthermore, an O-ring 11 is provided between the contact surface of the clamping nut 7 and the injector body 1.

[0032] like Figure 3 A dynamically adjustable fuel injection system includes a dynamically adjustable fuel injector K6, a fuel-water separator K1, a manual pump K2, a low-pressure delivery pump K3, a fuel filter K4, a fuel injection pump K5, and a throttle valve K8.

[0033] The output pipe of the oil-water separator K1 is connected to the manual pump K2 and the low-pressure delivery pump K3 respectively. Both the manual pump K2 and the low-pressure delivery pump K3 are connected to the inlet of the fuel filter K4. The output pipe of the fuel filter K4 is divided into two paths: one path enters the low-pressure fuel inlet 3 of the injector K6, and the other path enters the injection pump K5. The output end of the injection pump K5 is connected to the high-pressure fuel inlet 13 of the injector K6 and the oil-water separator K1 respectively. The number of cylinders of the injection pump K5 and the number of injectors K6 are consistent with the actual number of cylinders of the diesel engine.

[0034] Among them, a throttle valve K8 is installed on the pipeline between the fuel filter K4 and the injector K6 to regulate the pressure of the low-pressure fuel entering the injector K6.

[0035] In order to achieve the reuse of low-pressure fuel, the return port 12 on the injector K6 is connected to the output pipeline of the oil-water separator K1 through a pipeline.

[0036] To prevent fuel backflow, a one-way valve K7 is installed on the output line of the oil-water separator K1.

[0037] In use: Fuel filtered by fuel filter K4 enters the injector body 1 through low-pressure fuel inlet 3. The pressure of low-pressure fuel is adjusted by throttle valve K8. The pressure at spring seat push rod 4 is adjusted according to different speeds to achieve dynamic adjustment of injection.

[0038] The parts of the invention not described in detail are prior art. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dynamically pressure-regulatable fuel injection system, characterized by: It includes fuel injectors (K6), fuel-water separators (K1), manual pumps (K2), low-pressure delivery pumps (K3), fuel filters (K4), fuel injection pumps (K5), and throttle valves (K8). The injector (K6) includes an injector body (1), a spring seat top rod (4), an adjusting shim (5), a compression spring (6), a clamping nut (7), a needle valve limit plate (8), and a nozzle (9). The upper end of the injector body (1) is provided with a high-pressure oil inlet (13). The spring seat top rod (4), adjusting shim (5), compression spring (6), needle valve limit plate (8), and nozzle (9) are installed in the injector body (1) from top to bottom, and are sealed by the clamping nut (7) threadedly connected to the lower end of the outer side of the injector body (1). The upper end of the outer side of the injector body (1) is provided with a low-pressure fuel inlet (3), and the low-pressure fuel inlet (3) is connected to the channel provided above the spring seat top rod (4). The low-pressure fuel inlet (3) is used to receive fuel filtered by the fuel filter. As the rotation speed varies, the fuel pressure at the spring seat push rod (4) is different, so as to achieve the purpose of dynamically adjusting the injection pressure. The lower end of the outer side of the injector body (1) is provided with an oil return port (12), which is connected to the oil return passage located at the gap position of the needle valve limit plate (8). The nozzle (9) includes a needle valve body (91) and a needle valve (92). The needle valve (92) is located inside the needle valve body (91). The amount of fuel injected is adjusted by the relative movement of the needle valve (92) and the needle valve body (91). The injector body (1) is provided with a slit filter element (2), which corresponds to the high pressure inlet (13) and is used to filter the high pressure fuel entering the injector body (1). The spring seat top rod (4) is an integral structure of the spring seat and the long top rod; The needle valve body (91) and the needle valve limit plate (8) are connected by a positioning pin (10); An O-ring (11) is provided between the contact surface of the clamping nut (7) and the injector body (1). The output pipe of the oil-water separator (K1) is connected to the manual pump (K2) and the low-pressure delivery pump (K3) respectively. The manual pump (K2) and the low-pressure delivery pump (K3) are both connected to the oil inlet of the fuel filter (K4). The output pipe of the fuel filter (K4) is divided into two paths. One path enters the low-pressure fuel inlet (3) of the injector (K6), and the other path enters the fuel injection pump (K5). The output end of the fuel injection pump (K5) is connected to the high-pressure fuel inlet (13) of the injector (K6) and the oil-water separator (K1) respectively. A throttle valve (K8) is installed on the pipeline between the fuel filter (K4) and the injector (K6) to regulate the pressure of the low-pressure fuel entering the injector (K6).

2. A dynamically pressure-regulated fuel injection system according to claim 1, characterized in that: The return port (12) on the injector (K6) is connected to the output pipeline of the oil-water separator (K1) via a pipeline.

3. The dynamically adjustable fuel injection system according to claim 1, characterized in that: A one-way valve (K7) is installed on the output pipeline of the oil-water separator (K1).

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