A pencil type common rail fuel injector

Abstract

The application discloses a pencil type common rail oil injector, which comprises an injector body, a sunken electromagnetic valve, an armature, a planar control valve component, an oil nozzle coupling and an injector spring; a spring washer is arranged on the upper end surface of the sunken electromagnetic valve, and the sunken electromagnetic valve is compressed by the spring washer to obtain a certain force value; the armature is provided with a T-shaped integrated upper guide structure, a sealing element accommodating cavity is arranged on the head of the armature, the tail of the armature is attached to the spring, and the T-shaped guide part is slidably matched with the middle hole of the sunken electromagnetic valve; the planar control valve component comprises a sealing element, a biasing planar valve plate and a hole plate type oil inlet and outlet control valve; the sealing element is arranged in the sealing element accommodating cavity, and one side of the planar valve plate is attached to the biasing planar valve plate to realize sealing; the biasing planar valve plate and the hole plate type oil inlet and outlet control valve are both designed in a hole plate type structure, sealing is realized by planar compression, the planar valve structure of the biasing planar valve plate is arranged on one side of the hole plate, and the hole plate type oil inlet and outlet control valve is integrated with an oil inlet and outlet channel and is arranged in parallel on both sides of the center line.

Description

Technical Field

[0001] This application relates to the field of high-pressure common rail technology for diesel engines, and more particularly to a pencil-type common rail injector. Background Technology

[0002] To meet increasingly stringent environmental and energy conservation requirements, and to improve diesel engine performance, reduce emissions, and ensure better product reliability, high-pressure common rail injectors are increasingly being used in diesel engines below 37kW. While this brings many advantages and development prospects, it still faces some potential bottlenecks, including cost, technology, space limitations, market demand, and fuel quality requirements. For low-power diesel engines, the manufacturing and maintenance costs of high-pressure common rail injectors are relatively high, limiting their adoption. Low-power engines are typically small and have limited space; installing high-pressure common rail injectors may require structural adjustments, increasing complexity and cost. High-pressure common rail injectors have high fuel quality requirements, necessitating the use of high-quality fuel. In some regions or application scenarios, fuel quality may not meet the requirements of high-pressure common rail injectors. High-pressure common rail injectors require precise control technology and highly sophisticated manufacturing processes; issues such as achieving high-pressure injection within a limited space and maintaining injector stability all constrain the application of high-pressure common rail injectors in diesel engines below 37kW.

[0003] To address the bottleneck problem of low-power diesel engines, a common rail injector was invented that is small in size, can be flexibly adapted to different installation spaces, and retains the performance and reliability advantages of common rail injectors without sacrificing system strength and rigidity. Summary of the Invention

[0004] To address the problems existing in the prior art, the purpose of this application is to provide a pencil-type common rail injector, the technical solution of which is as follows:

[0005] A pencil-type common rail injector includes an injector body, a sinking solenoid valve, an armature, a flat control valve assembly, a nozzle assembly, and an injector spring.

[0006] A spring washer is installed on the upper end face of the sinking solenoid valve. The spring washer contacts the inner end face of the injector body. A certain force is obtained by compressing the spring washer to press the sinking solenoid valve.

[0007] The armature is a T-shaped integrated upper guide structure. The head of the T-shaped structure is provided with a sealing cavity, the tail of the T-shaped structure is in contact with the spring, and the T-shaped guide part slides in cooperation with the middle hole of the sinking solenoid valve.

[0008] The planar control valve component includes a seal, an offset planar valve plate, and an orifice plate inlet / outlet control valve. The seal is installed in the seal cavity, with its planar side fitting and sealing against the offset planar valve plate. Both the offset planar valve plate and the orifice plate inlet / outlet control valve adopt an orifice plate structure design, achieving sealing through planar pressing. The offset planar valve has its planar valve structure located on one side of the orifice plate. The orifice plate inlet / outlet control valve integrates inlet and outlet channels, arranged parallel to each other on both sides of the centerline.

[0009] The nozzle assembly, after being combined with the injector spring, is connected via a locating pin, an orifice-type inlet / outlet oil control valve, and an offset flat valve plate.

[0010] Furthermore, the structure of the sealing cavity is a single cone, a cone with a guide cylinder, or a sphere.

[0011] Furthermore, the spring is placed in the central hole of the sinking solenoid valve, and the T-shaped tail of the armature is inserted into the sinking solenoid valve and fits against the spring.

[0012] Furthermore, the armature, spring, and sinking solenoid valve are assembled and installed in the inner cavity of the injector body, and the inner cavity is the receiving cavity of the sinking solenoid valve.

[0013] Furthermore, the nozzle assembly includes a needle valve and a needle valve body, wherein the needle valve and the needle valve body are coupled together to form the nozzle assembly.

[0014] Furthermore, the sealing element is a spherical planar structure of greater than or equal to 1 / 2 spherical shape.

[0015] Furthermore, the injector body component includes a sealing gasket, a connector harness, an injector body, and a return pipe connector connected in sequence, with each component connected by a locating pin and a nozzle cap.

[0016] The technical solutions provided by the embodiments of this application may include the following beneficial effects:

[0017] ① Its outer diameter at its thickest point is less than 17mm, and the injector is small in size, which solves the problem of limited installation space. It can be embedded in the engine block, and has strong installation flexibility. The inlet and outlet structure is directly integrated into the injector.

[0018] ② The solenoid valve uses electromagnetic force to attract and drop the armature, thereby controlling the fuel injector to spray. It has a compact structure, fast opening and closing speed, and low electromagnetic force.

[0019] ③ For engines with power below 37kw, it replaces mechanical fuel injectors, reducing fuel consumption and is cheaper.

[0020] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0022] Figure 1 This is a schematic diagram of a pencil-type common rail injector according to an exemplary embodiment.

[0023] Figure 2 This is a schematic diagram of the structure of an orifice plate type inlet / outlet oil control valve according to an exemplary embodiment.

[0024] Figure 3 This is a schematic diagram of the structure of a biased planar valve plate according to an exemplary embodiment.

[0025] 1. Spring; 2. Orifice plate type inlet / outlet oil control valve; 3. Seal; 4. Armature; 5. Recessed solenoid valve; 6. Offset flat valve plate; 201. Orifice plate type inlet / outlet oil control valve outlet; 202. Oil inlet; 601. Transverse oil passage; 602. Offset flat valve plate outlet; 7. Return oil pipe; 8. Nozzle assembly; 9. Second pressure chamber; 10. Injector spring; 11. First pressure chamber. Detailed Implementation

[0026] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application.

[0027] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0028] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0029] This invention provides a pencil-type common rail injector, comprising: an injector body component, a recessed solenoid valve 5, an armature 4, a planar control valve component, a nozzle assembly 8, and an injector spring 10. The components are connected by locating pins and nozzle caps. A spring washer is mounted on the upper surface of the recessed solenoid valve 5, and the spring washer contacts the inner end face of the injector body. A certain force is obtained by compressing the spring washer to press the recessed solenoid valve 5. The armature 4 is a T-shaped integrated upper guide structure. The T-shaped head has a sealing cavity, the T-shaped tail fits against the spring, and the T-shaped guide portion slides with the central hole of the recessed solenoid valve. The planar control valve component includes a seal 3, an offset planar valve plate 6, and an orifice plate inlet / outlet control valve 2. The seal 3 is mounted on... In the cavity of the sealing element, one side of the plane is fitted and sealed with the offset plane valve plate 6; both the offset plane valve plate 6 and the orifice plate inlet / outlet oil control valve 2 adopt an orifice plate structure design, and the sealing is achieved by plane pressing. The offset plane valve plate 6 has its plane valve structure set on one side of the orifice plate. The orifice plate inlet / outlet oil control valve 2 integrates the inlet and outlet oil channels, which are arranged in parallel on both sides of the center line; after the nozzle assembly 8 is combined with the injector spring 10, it is connected to the orifice plate inlet / outlet oil control valve 2 and the offset plane valve plate 6 through the positioning pin.

[0030] Specifically, the submerged solenoid valve 5 adopts a submerged structure. The outer diameter of the solenoid valve is clearance-fitted with the central hole of the injector body. A spring washer is installed on the upper end face of the solenoid valve, and the spring washer contacts the inner end face of the injector body. A certain force is obtained by compressing the spring washer, thus pressing the solenoid valve. By submerging the electromagnet and valve core assembly below the injector body, the mass and inertia of the control valve can be reduced, the response speed of the solenoid valve can be improved, more precise fuel injection control can be achieved, and noise and vibration can be reduced. It also has the benefit of improving fuel system efficiency and fuel utilization.

[0031] The armature 4 is a T-shaped integrated upper guide structure. The head of the T-shaped structure is provided with a sealing cavity. Its structure can be a separate cone, a cone with a guide cylinder, or a sphere. The tail of the T-shaped structure is in contact with the spring 1. The T-shaped guide part slides in cooperation with the middle hole of the sinking solenoid valve 5. Unlike the separate design of the armature 4, armature 4 rod, and ball valve seat of a typical injector, this design can greatly avoid the waste of design space caused by excessive connection structure design. It occupies less space, which is conducive to the reduction of the overall structure of the injector and solves the problem of limited installation space.

[0032] The armature 4, spring 1, and retractable solenoid valve 5 are assembled and installed in the inner cavity of the injector body, which serves as the receiving cavity for the retractable solenoid valve 5. Spring 1 is placed in the central hole of the retractable solenoid valve 5, and the tail of armature 4 is inserted into the retractable solenoid valve 5 and fits against spring 1. After assembly, spring 1 is in a compressed state, constantly applying pressure to armature 4 and seal 3, pressing seal 3 against the offset plane valve plate 6. When the solenoid valve is not working, seal 3 is pressed against the offset plane valve plate 6 by the spring force, the injector is in a sealed state, the high and low pressure areas are not connected, and the injector does not spray fuel. When the solenoid valve is working, the electromagnetic force is greater than the spring force, armature 4 is attracted by the solenoid valve, and seal 3 is lifted under the action of high-pressure fuel in the high-pressure area, and the injector begins to spray fuel.

[0033] The aforementioned planar control valve component is a planar sealed switching valve with low electromagnetic force requirements, effectively reducing the size of the solenoid valve. It consists of a seal 3, an offset planar valve plate 6, and an orifice plate type inlet / outlet oil control valve 2. The seal 3 has a spherical planar structure greater than or equal to 1 / 2 spherical shape, providing good sealing, annular surface contact, low contact stress, and good durability. It is installed in the seal 3 accommodating cavity of the armature 4, with its planar side fitting tightly against the offset planar valve plate 6 for sealing. Figure 2 and Figure 3 As shown, both the offset planar valve plate 6 and the orifice plate inlet / outlet control valve 2 adopt an orifice plate structure design, achieving sealing through planar pressing. The offset planar valve has its planar valve structure positioned on one side of the orifice plate, not centrally located. This planar valve structure design requires less electromagnetic force, effectively reducing the size of the solenoid valve and allowing it to sink, thus reducing the injector size. The inlet / outlet control method integrates the inlet / outlet ports onto the valve plate, simplifying the parts, facilitating machining, and reducing the injector size. The orifice plate inlet / outlet control valve 2 integrates inlet / outlet channels, arranged parallel to each other on both sides of the centerline, effectively reducing the size of the parts.

[0034] The injector assembly includes a needle valve and a needle valve body, with the volume at the tail of the needle valve and needle valve body forming a second pressure chamber 9. The injector body assembly consists of a sealing gasket, a connector harness, the injector body, and a return oil pipe connector connected sequentially. Each component is connected via a locating pin and an injector cap. The needle valve and needle valve body form a pair (paired relationship), which in turn forms the injector assembly. The injector assembly, combined with the injector spring 10, is connected via a locating pin, an orifice-type inlet / outlet control valve 2, and an offset flat valve plate 6 (this is the lower part of the injector). The armature, armature stroke adjustment ring, and solenoid valve are installed in the central hole of the injector body (this is the upper part of the injector). Finally, the upper and lower parts are tightened together as a single unit using the injector cap via a threaded connection (the return oil pipe connector is pre-installed on the injector body).

[0035] Single-component low-inertia design refers to the use of a simple, lightweight component with low inertia in mechanical system design. This design effectively reduces the system's inertia, thereby improving its response speed and dynamic performance. In traditional mechanical design, to meet strength and stiffness requirements, thicker components are often used, which increases the system's inertia. Increased inertia reduces the system's acceleration and deceleration, thus lowering its response speed and dynamic performance. Single-component low-inertia design reduces inertia by optimizing component structure and reducing material usage, thereby improving performance. Common single-component low-inertia designs include using lightweight materials, employing thin-walled structures, and reducing component mass. Using single-component low-inertia design can improve system response speed and dynamic performance without sacrificing system strength and stiffness. This is crucial in applications with high speed and precision requirements. In this application, the inertia is reduced by decreasing the mass and volume of the armature 4 and the sinking solenoid valve 5.

[0036] The working principle of this pencil-type common rail injector is as follows: the injector's internal oil circuit is divided into high-pressure and low-pressure parts by a planar control valve component. High-pressure oil flows in from the inlet pipe interface, and through the inlet hole, it connects to the first pressure chamber 11 (the chamber left in the front middle of the needle valve body) and the second pressure chamber 9 of the needle valve body. This part is the high-pressure area. After the seal is opened, the oil flows into the return pipe 7 through the offset planar valve plate outlet 602. This part is the low-pressure area.

[0037] High-pressure oil enters the oil passage through the inlet 202 of the injector body, flows through the offset planar valve plate 6 and the orifice plate inlet / outlet control valve 2, and reaches the nozzle assembly. When the solenoid valve is energized, it generates electromagnetic force to attract the armature 4, and the seal 3 is lifted under hydraulic pressure. The high-pressure oil in the second pressure chamber 9 is released into the low-pressure chamber through the outlet 201 and the outlet 602 of the offset planar valve plate. At the same time, high-pressure oil continuously flows into the second pressure chamber 9 through the outlet of the orifice plate inlet / outlet control valve 2. Since the flow rate of the outlet of the orifice plate inlet / outlet control valve 2 is higher than that of the inlet, the pressure in the pressure chamber decreases, the pressure on the needle valve decreases, and the oil flows through the outlet 602 of the offset planar valve plate. 2. The oil flows into the return pipe 7. Under the action of hydraulic pressure, the needle valve overcomes the force of the spring 1 and opens, and the injector starts to spray. When the solenoid valve is de-energized, the armature 4 sits down under the preload of the solenoid valve spring 1, presses the seal 3, and closes the oil outlet 602 of the offset plane valve plate. The high-pressure oil enters the first pressure chamber 11 through the transverse oil passage 601 on the offset plane valve plate and the oil inlet 202, so that high pressure is established in the first pressure chamber 11, the needle valve pressure increases, the needle valve sits down under the action of hydraulic pressure, and the injector stops spraying.

[0038] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0039] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A pencil-type common rail injector, characterized in that, Includes injector body, sinking solenoid valve, armature, flat control valve assembly, nozzle assembly and injector spring; A spring washer is installed on the upper end face of the sinking solenoid valve. The spring washer contacts the inner end face of the injector body. A certain force is obtained by compressing the spring washer to press the sinking solenoid valve. The armature is a T-shaped integrated upper guide structure. The head of the T-shaped structure is provided with a sealing cavity. The structure of the sealing cavity is a separate cone, a cone with a guide cylinder, or a sphere. The tail of the T-shaped structure is in contact with the spring. The guide part of the T-shaped structure slides in cooperation with the middle hole of the sinking solenoid valve. The spring is placed in the middle hole of the sinking solenoid valve. The tail of the armature is inserted into the sinking solenoid valve and contacts the spring. The planar control valve component includes a seal, an offset planar valve plate, and an orifice plate inlet / outlet control valve. The seal is a planar structure of at least 1 / 2 spherical shape, installed in the seal's accommodating cavity, with one planar side fitting and sealing against the offset planar valve plate. Both the offset planar valve plate and the orifice plate inlet / outlet control valve adopt an orifice plate structure design, achieving sealing through planar pressing. The offset planar valve has its planar valve structure located on one side of the orifice plate. The orifice plate inlet / outlet control valve integrates inlet and outlet channels, arranged parallel to each other on both sides of the centerline. The nozzle assembly, after being combined with the injector spring, is connected via a locating pin, an orifice-type inlet / outlet oil control valve, and an offset flat valve plate.

2. The pencil-type common rail injector according to claim 1, characterized in that, The armature, spring, and sinking solenoid valve are assembled and installed in the inner cavity of the injector body, and the inner cavity is the receiving cavity of the sinking solenoid valve.

3. The pencil-type common rail injector according to claim 1, characterized in that, The nozzle assembly includes a needle valve and a needle valve body, which are coupled together to form the nozzle assembly.

4. The pencil-type common rail injector according to claim 1, characterized in that, The injector body component includes a sealing gasket, a connector harness, an injector body, and a return pipe connector connected in sequence. Each component is connected by a locating pin and a nozzle cap.

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